bluuebunny/crossref_metadata_2025 huggingface dataset:
A reliability-centred maintenance strategy based on maintenance-free operating period philosophy and total lifetime operating cost analysis
Authors: Long J , Shenoi R A , Jiang W
Published: May 2009

Maintenance intervention is necessary for the equipment, such as aircraft structures and systems, to maintain their operational performance status during their lifetime. Generally maintenance costs make a significant contribution to overall operating costs. Accordingly, developing an optimal maintenance strategy to minimize maintenance costs and total lifetime operating cost (TLOC) is a critical task. This article proposes a methodology for the optimization of a reliability-centred maintenance strategy based on maintenance-free operating period (MFOP) philosophy by considering the TLOC. The method can be used to evaluate the TLOC of alternative maintenance strategies and determine the optimal maintenance interval while meeting the proposed reliability requirements. The method is also suitable for evaluating and optimizing the MFOP-based reliability design of the products. An example based on line replaceable unit replacement strategy is introduced to illustrate the proposed maintenance strategy optimization approach. And a sensitivity analysis on the TLOC index for each of the two reliability requirement parameters is also performed.
Stress analysis in the mandibular condyle during prolonged clenching: A theoretical approach with the finite element method
Authors: Nishio C , Tanimoto K , Hirose M , Horiuchi S , Kuroda S , Tanne K , Tanaka E
Published: May 2009

Parafunctional habits, such as bruxism and prolonged clenching, have been associated with functional overloading in the temporomandibular joint (TMJ), which may result in internal derangement and osteoarthrosis of the TMJ. In this study, the distributions of stress on the mandibular condylar surface during prolonged clenching were examined with TMJ mathematical models. Finite element models were developed on the basis of magnetic resonance images from two subjects with or without anterior disc displacement of the TMJ. Masticatory muscle forces were used as a loading condition for stress analysis during a 10 min clenching. In the asymptomatic model, the stress values in the anterior area (0.100 MPa) and lateral area (0.074 MPa) were relatively high among the five areas at 10 min. In the middle and posterior areas, stress relaxation occurred during the first 2 min. In contrast, the stress value in the lateral area was markedly lower (0.020 MPa) than in other areas in the symptomatic model at 10 min. The largest stress (0.050 MPa) was located in the posterior area. All except the anterior area revealed an increase in stress during the first 2 min. The present result indicates that the displacement of the disc could affect the stress distribution on the condylar articular surface during prolonged clenching, especially in the posterior area, probably leading to the cartilage breakdown on the condylar articular surface.
Design and evaluation of a novel triaxial isometric trunk muscle strength measurement system
Authors: Azghani M R , Farahmand F , Meghdari A , Vossoughi G , Parnianpour M
Published: May 2009

Maximal strength measurements of the trunk have been used to evaluate the maximum functional capacity of muscles and the potential mechanical overload or overuse of the lumbar spine tissues in order to estimate the risk of developing musculoskeletal injuries. A new triaxial isometric trunk strength measurement system was designed and developed in the present study, and its reliability and performance was investigated. The system consisted of three main revolute joints, equipped with torque sensors, which intersect at L5—S1 and adjustment facilities to fit the body anthropometry and to accommodate both symmetric and asymmetric postures in both seated and standing positions. The dynamics of the system was formulated to resolve validly the moment generated by trunk muscles in the three anatomic planes. The optimal gain and offset of the system were obtained using deadweights based on the least-squares linear regression analysis. The R2 results of calibration for all loading courses of all joints were higher than 0.99, which indicated an excellent linear correlation. The results of the validation analysis of the regression model suggested that the mean absolute error and the r.m.s. error were less than 2 per cent of the applied load. The maximum value of the minimum detectable change was found to be 1.63 N m for the sagittal plane torque measurement, 0.8 per cent of the full-scale load. The trial-to-trial variability analysis of the device using deadweights provided intra-class correlation coefficients of higher than 0.99, suggesting excellent reliability. The cross-talk analysis of the device indicated maximum cross-talks of 1.7 per cent and 3.4 per cent when the system was subjected to flexion—extension and lateral bending torques respectively. The trial-to-trial variability of the system during in-vivo strength measurement tests resulted in good to excellent reliability, with intra-class correlation coefficients ranging from 0.69 to 0.91. The results of the maximum voluntary isometric torques exertion measurements for 30 subjects indicated good agreement with the previously published data in the literature. The extensive capabilities and high reliability of the system are promising for more comprehensive investigations on the trunk biomechanics in future, e.g. isometric strength measurement at symmetric and asymmetric postures, muscle endurance, and recruitment pattern analysis.
High-solid-content hydroxyapatite slurry for the production of bone substitute scaffolds
Authors: Cunningham E , Dunne N , Walker G , Buchanan F
Published: May 2009

Key to various bone substitute scaffold production techniques is the development of free-flowing ceramic slurry with optimum rheological properties. The aim is to achieve a colloidal suspension with as high a solid content as possible while maintaining a low viscosity which easily penetrates the pores of relevant sacrificial templates. The following investigation describes the optimization of a hydroxyapatite slip and demonstrates its potential application in scaffold production. Using predominantly spherical particles of hydroxyapatite of between 0.82 μm and 16.2 μm, coupled with a 2 wt % addition of the anionic polyelectrolyte, ammonium polyacrylate, an 80 wt % (55.9 vol %) hydroxyapatite solid loaded slip with a viscosity of approximately 126 mPa s has been developed. Its ability to infiltrate and replicate porous preforms has been shown using polyurethane foam. The enhanced particle packing achieved has allowed for the production of scaffolds with highly dense and uniform grain structures. The results represent a significant improvement in current slurry production techniques and can be utilized to develop high-density ceramic bone substitute scaffolds.
Calibration of a meanline centrifugal pump model using evolutionary algorithms
Authors: Benini E , Cenzon M
Published: May 2009

A one-dimensional meanline prediction code suitable for performance prediction of small-to-medium size turbopumps (3–40 kW) is developed, which is able to predict both on and off-design performance of a turbopump given the loss of the diffusion system at the design point. This model is then calibrated against experimental data using an optimization technique. Due to the rapidity of code computations, a single-objective evolutionary algorithm is used for model calibration in order to obtain a wide exploration of the search space. Accuracy of the calibrated model is finally demonstrated by means of a comparison between predicted and actual pump performance.
Performance characteristics of natural-refrigerants- based ejector expansion refrigeration cycles
Authors: Sarkar J
Published: May 2009

The thermodynamic analyses and comparison of three natural-refrigerants-based vapour compression refrigeration cycles (ammonia, isobutane, and propane) are presented in this article using a constant pressure mixing ejector as an expansion device. Optimization of the area ratio of the ejector is done based on maximum cooling coefficient of performance (COP) and performance improvement for different operating conditions. The effect of using an internal heat exchanger is studied as well. Results show that optimum area ratio and cooling COP increases with a decrease in cycle temperature lift, whereas the COP improvement over basic expansion cycle increases with the increase in cycle temperature lift. Study shows that the optimum parameters, as well as performance using the ejector as an expansion device, are strongly dependent on the refrigerant properties as well as the operating conditions. The optimum area ratio is maximum for ammonia and minimum for propane, whereas maximum cooling COPs are similar. Using the ejector as an expansion device, propane yields a maximum COP improvement of 26.1 per cent followed by isobutane (22.8 per cent) and ammonia (11.7 per cent) for studies ranges. The effect of using an internal heat exchanger in the ejector expansion refrigeration cycle is found to be not profitable.
Tribology research trends in Italy
Authors: Ciulli E
Published: May 2009

This article furnishes a survey of recent investigations and of the current tribology research trends in Italy. Several topics related to tribology are investigated in several different departments of universities, research centres, and industries. Some basic studies on friction and lubrication at the atomic-scale level are also reported. A big effort is addressed to researches on surface topography, contact mechanics aspects, and particularly on surface coatings and treatments. Indentation and scratching techniques are used for the characterization of both coatings and bulk materials down to the nanoscale. Mechanical characterization of materials and mat- erial processing involve tribological aspects too. Investigations on the wear behaviour of different materials for applications in the field of biotribology are also being carried out. The increasing interest of the industrial world in tribological problems is producing a lot of collaborations among universities, research centres, and industries. Several tribological components and practical applications are investigated, such as lubricated sliding bearings, gas and magnetic bearings, gears, sealing systems, and automotive and rail components. Investigations are often completed by diagnostic studies for monitoring or maintenance purposes.
Modelling and simulation of thermal effects in wet clutches operating under boundary lubrication conditions
Authors: Marklund P , Sahlin F , Larsson R
Published: May 2009

Wet clutches are frequently used in the drive trains of many modern vehicles. The behaviour of the clutches influences the behaviour of the whole drive train and therefore of the whole vehicle. The design of the clutch is very important because it operates in cooperation with the other parts of the drive train. The clutch also often has to work in the lubricant present in the transmission. To optimize the clutch for an application, properties such as disc geometry, materials, friction disc surface, and engagement axial force can be varied when designing the clutch. Today, the design process involves much testing, which is expensive and time consuming. There are no good hand-book solutions or engineering tools available, hence the designer has to be very experienced and often use trial and error methods in order to end up with a working clutch for an application.

A simulation model is developed in this article, which in combination with a simple measurement technique for measuring the boundary lubrication friction coefficient is used to estimate temperature and torque transfer for a wet clutch working under limited slip conditions. The developed simulation model can be used as a design tool for wet clutches. The approach developed in this article can be used to investigate torque behaviour for wet clutches that have not been designed and is, therefore, suitable to use when optimizing the performance of a new clutch. The model includes fluid dynamics, contact mechanics, and temperature computations in the fluid film between the friction disc and the separator disc. Temperature computations in the clutch discs are also included in the model. The fluid dynamics calculations use homogenized flow factors to enable simulations of flow on a coarser grid and still include all surface roughness effects. The temperature distribution in the film in the sliding interface is approximated as a polynomial of the second order. The heat transfer in the grooves of the friction discs is solved by means of an equilibrium equation that includes radial cooling flow effects because of centrifugal flows. The temperature in the friction disc and separator disc is obtained from the solution of the full three-dimensional energy equation in polar cylindrical coordinates.

The model is validated by measurements made in a test rig and good agreement between measurements and simulations is obtained, both with regard to temperature and transfered torque.

The use of this model can reduce the time needed to develop a limited slip wet clutch application since the systematic way of finding the optimal clutch design will be more efficient than the often used Edisonian trial and error approach.
Self-lubricating chromium carbide/amorphous hydrogenated carbon nanocomposite coatings: A new alternative to tungsten carbide/amorphous hydrogenated carbon
Authors: Mitterer C , Lechthaler M , Gassner G , Fontalvo G A , Tóth L , Pécz B , Raible M , Maier K , Bergmann E
Published: May 2009

In the automotive industry, there is an increasing demand to apply self-lubricious coatings to reduce fuel and oil consumption. Within this work, self-lubricious nanocomposite coatings consisting of 1-3.5 nm sized CrC nanocrystals embedded in an amorphous hydrogenated carbon (a-C:H) matrix have been developed in a laboratory-scale sputtering system and up-scaled to a production-type plant. The nanostructure and composition of these coatings are presented and correlated to mechanical and tribological properties. With hardness values of about 11 GPa, dry-sliding friction coefficients between 0.08 and 0.18, and wear rates between 3.9×10−16 and 2.8×10−15 m3/N/m, the coatings outperform present state-of-the-art WC/a-C:H coatings and seem to be excellent candidates for applications in automotive engines and drivetrain systems.
Finite element analysis of a Timoshenko beam traversed by a moving vehicle
Authors: Moghaddas M , Sedaghati R , Esmailzadeh E , Khosravi P
Published: May 2009

In this study the finite element formulation for the dynamics of a bridge traversed by moving vehicles is presented. The vehicle including the driver and the passenger is modelled as a half-car planner model with six degree of freedom, travelling on the bridge with constant velocity. The bridge is modelled as a uniform beam with simply supported end conditions that obeys the Timoshenko beam theory. The governing equations of motion are derived using the extended Hamilton principle and then transformed into the finite element format by using the weak-form formulation. The Newmark-β method is utilized to solve the governing equations and the results are compared with those reported in the literature. Furthermore, the maximum values of deflection for the Timoshenko and Euler—Bernoulli beams have been compared. The results illustrated that as the velocity of the vehicle increases, the difference between the maximum beam deflections in the two beam models becomes more significant.
Non-linear elastic ring tyre model using the absolute nodal coordinate formulation
Authors: Sugiyama H , Suda Y
Published: May 2009

In this investigation, a non-linear elastic ring tyre model is developed. The elastic deformation of the tyre belt is modelled using the finite element absolute nodal coordinate formulation that allows for describing large rotational motion and the non-linear inertia effects; the curved structure of the tyre belt; and moving boundary resulting from the tread and road interaction. Using a concept of elastic ring tyre models, the sidewall flexibility of a tyre is modelled using circumferential and radial springs and dampers defined between the belt and rim, while the tangential tyre force is modelled using friction elements defined at contact nodes defined within the curved belt elements. Numerical examples are presented in order to demonstrate the use of the flexible tyre model developed in this investigation. Good agreements are demonstrated in the tyre vibration characteristics obtained using the experiments and the proposed model. It is presented that the proposed tyre model can be used for assessing dynamic characteristics of tyres in high frequency ranges resulting from the interaction to uneven road surfaces.
Vortex ring-like structures in gasoline fuel sprays under cold-start conditions
Authors: Begg S , Kaplanski F , Sazhin S , Hindle M , Heikal M
Published: May 2009

A phenomenological study of vortex ring-like structures in gasoline fuel sprays is presented for two types of production fuel injectors: a low-pressure, port fuel injector (PFI) and a high-pressure atomizer that injects fuel directly into an engine combustion chamber (G-DI). High-speed photography and phase Doppler anemometry (PDA) were used to study the fuel sprays. In general, each spray was seen to comprise three distinct periods: an initial, unsteady phase; a quasi-steady injection phase; and an exponential trailing phase. For both injectors, vortex ring-like structures could be clearly traced in the tail of the sprays. The location of the region of maximal vorticity of the droplet and gas mixture was used to calculate the temporal evolution of the radial and axial components of the translational velocity of the vortex ring-like structures. The radial components of this velocity remained close to zero in both cases. The experimental results were used to evaluate the robustness of previously developed models of laminar and turbulent vortex rings. The normalized time, , and normalized axial velocity, , were introduced, where tinit is the time of initial observation of vortex ring-like structures. The time dependence of on was approximated as and for the PFI and G-DI sprays respectively. The G-DI spray compared favourably with the analytical vortex ring model, predicting , in the limit of long times, where α = 3/2 in the laminar case and α = 3/4 when the effects of turbulence are taken into account. The results for the PFI spray do not seem to be compatible with the predictions of the available theoretical models.
Light scattering technique for estimating soot mass loading in diesel particulate filters
Authors: Kamimoto T , Murayama Y , Minagawa T , Minami T
Published: May 2009

The real-time estimation of soot mass loading on diesel particulate filters (DPF) is essential to assure perfect and fuel efficient regeneration. Computer models based on the pressure drop across the DPF are usually installed in the engine control unit to estimate the soot mass loading during vehicle driving, but this approach is still subject to uncertainty about the lack of resources available. The aim of this study is to develop a portable instrument that can make real-time measurements of soot mass loading under transient mode for calibrating the models. The instrument is based on the light scattering technique: A laser beam illuminates diesel particles in a small exhaust sample and the intensity of scattered light from soot particles is reduced to soot mass concentration using calibration data obtained under steady engine operating conditions. It is demonstrated that the prototype instrument can measure the temporal variations of cumulative soot mass and filtration efficiency of a diesel particulate filter under a transient mode, and that it has a minimum detectable concentration of 5 μg/m3, which is low enough to detect the particle breakthrough in the DPF. The proposed technique has potential to be applied for on-board diagnostics if the device is downsized.
RNase MRP is required for entry of 35S precursor rRNA into the canonical processing pathway
Authors: Lindahl Lasse , Bommankanti Ananth , Li Xing , Hayden Lauren , Jones Adrienne , Khan Miriam , Oni Tolulope , Zengel Janice M.
Published: May 2009

RNase MRP is a nucleolar RNA–protein enzyme that participates in the processing of rRNA during ribosome biogenesis. Previous experiments suggested that RNase MRP makes a nonessential cleavage in the first internal transcribed spacer. Here we report experiments with new temperature-sensitive RNase MRP mutants in Saccharomyces cerevisiae that show that the abundance of all early intermediates in the processing pathway is severely reduced upon inactivation of RNase MRP. Transcription of rRNA continues unabated as determined by RNA polymerase run-on transcription, but the precursor rRNA transcript does not accumulate, and appears to be unstable. Taken together, these observations suggest that inactivation of RNase MRP blocks cleavage at sites A0, A1, A2, and A3, which in turn, prevents precursor rRNA from entering the canonical processing pathway (35S > 20S + 27S > 18S + 25S + 5.8S rRNA). Nevertheless, at least some cleavage at the processing site in the second internal transcribed spacer takes place to form an unusual 24S intermediate, suggesting that cleavage at C2 is not blocked. Furthermore, the long form of 5.8S rRNA is made in the absence of RNase MRP activity, but only in the presence of Xrn1p (exonuclease 1), an enzyme not required for the canonical pathway. We conclude that RNase MRP is a key enzyme for initiating the canonical processing of precursor rRNA transcripts, but alternative pathway(s) might provide a backup for production of small amounts of rRNA.
Novel TUTase associates with an editosome-like complex in mitochondria of Trypanosoma brucei
Authors: Aphasizheva Inna , Ringpis Gene-Errol , Weng James , Gershon Paul D. , Lathrop Richard H. , Aphasizhev Ruslan
Published: May 2009

Expression of mitochondrial genomes in Kinetoplastida protists requires massive uracil insertion/deletion mRNA editing. The cascade of editing reactions is accomplished by a multiprotein complex, the 20S editosome, and is directed by trans-acting guide RNAs. Two distinct RNA terminal uridylyl transferases (TUTases), RNA Editing TUTase 1 (RET1) and RNA Editing TUTase 2 (RET2), catalyze 3′ uridylylation of guide RNAs and U-insertions into the mRNAs, respectively. RET1 is also involved in mitochondrial mRNA turnover and participates in numerous heterogeneous complexes; RET2 is an integral part of the 20S editosome, in which it forms a U-insertion subcomplex with zinc finger protein MP81 and RNA editing ligase REL2. Here we report the identification of a third mitochondrial TUTase from Trypanosoma brucei. The mitochondrial editosome-like complex associated TUTase (MEAT1) interacts with a 20S editosome-like particle, effectively substituting the U-insertion subcomplex. MEAT1 and RET2 are mutually exclusive in their respective complexes, which otherwise share several components. Similarly to RET2, MEAT1 is exclusively U-specific in vitro and is active on gapped double-stranded RNA resembling editing substrates. However, MEAT1 does not require a 5′ phosphate group on the 3′ mRNA cleavage fragment produced by editing endonucleases. The functional RNAi complementation experiments showed that MEAT1 is essential for viability of bloodstream and insect parasite forms. The growth inhibition phenotype in the latter can be rescued by coexpressing an RNAi-resistant gene with double-stranded RNA targeting the endogenous transcript. However, preliminary RNA analysis revealed no gross effects on RNA editing in MEAT1-depleted cells and indicated its possible role in regulating the mitochondrial RNA stability.
Mitochondrial tRNA import in Trypanosoma brucei is independent of thiolation and the Rieske protein
Authors: Paris Zdeněk , Rubio Mary Anne T. , Lukeš Julius , Alfonzo Juan D.
Published: May 2009

Due to a complete lack of the tRNA genes in the mitochondrial genome of Trypanosoma brucei, all tRNAs needed for mitochondrial translation have to be imported into the organelle from the cytosol. A previous study showed that the modified nucleotide s2U could act as a negative determinant for mitochondrial tRNA import in another kinetoplastid, Leishmania tarentolae. We have investigated whether the same type of cytosolic control for tRNA retention exists in T. brucei. Based on Northern analysis with subcellular RNA fractions and in vitro import assays, we demonstrate that silencing of the cysteine desulfurase, TbNfs (TbIscS), the key enzyme in tRNA thiolation (s2U) and Fe-S cluster formation in vivo, has no effect on tRNA partitioning. This observation is especially surprising in light of a recent report suggesting that in L. tropica the Rieske Fe-S protein is an essential component of the RNA import complex (RIC). In line with the above observation, we also show that down-regulation of the Rieske protein by RNA interference, similar to the TbNfs knockdowns, has no effect on import. The data presented here supports the view that in T. brucei: (1) s2U is not a negative determinant for tRNA import; (2) the Rieske protein is not an essential component of the import machinery, and (3) since the Rieske protein is essential for respiration and maintenance of inner mitochondrial membrane potential, neither process plays a critical role in tRNA import. We therefore suggest that the T. brucei import machinery differs substantially from what has been described in Leishmania.
Association of the Pro12Ala polymorphism in peroxisome proliferator-activated receptor γ2 with decreased basic metabolic rate in women with polycystic ovary syndrome
Authors: Koika Vasiliki , Marioli Dimitra J , Saltamavros Alexandros D , Vervita Vasiliki , Koufogiannis Kleanthis D , Adonakis George , Decavalas George , Georgopoulos Neoklis A
Published: May 2009

Objective

The peroxisome proliferator-activated receptor (PPAR)γ is a transcription factor involved in glucose homeostasis and energy metabolism. A missense mutation at codon 12 in the PPARγ2 has been associated with increased body mass index (BMI) and attenuated insulin resistance (IR) in polycystic ovary syndrome (PCOS). We have recently shown a decreased basic metabolic rate (BMR) in PCOS. The aim of the present study is to determine the prevalence of the Pro12Ala polymorphism of the PPARγ2 gene and its associations with indices of IR and BMR in lean and slightly overweight PCOS women.

Design

Case–control association study involving 156 PCOS women with biochemical hyperandrogenism, chronic anovulation and polycystic ovarian morphology in ultrasound and 56 unrelated healthy controls.

Methods

Hormonal determinations were performed by electrochemiluminescence quantitation or RIA. BMR was measured by indirect calorimetry. All subjects were genotyped by a PCR–restriction fragment length polymorphism assay.

Results

Genotype frequencies of the Pro12Ala polymorphism in PPARγ2 did not differ among PCOS women and control subjects.

The presence of Pro12Ala polymorphism of PPARγ2 was associated with lower BMR (P=0.04). This finding was valid in our subgroup of lean PCOS (BMI<25 kg/m2), in which the Ala variant was also associated with higher total testosterone values.

Conclusion

The Pro12Ala polymorphism in the PPARγ2 gene is associated with decreased BMR in women with PCOS and biochemical hyperandrogenemia. These young women are therefore at risk to increase their body weight and should restrict their energy intake by diet and enhance their energy expenditure by exercise.
High-dose intramuscular octreotide in patients with acromegaly inadequately controlled on conventional somatostatin analogue therapy: a randomised controlled trial
Authors: Giustina Andrea , Bonadonna Stefania , Bugari Giovanna , Colao Annamaria , Cozzi Renato , Cannavo Salvatore , de Marinis Laura , degli Uberti Ettore , Bogazzi Fausto , Mazziotti Gherardo , Minuto Francesco , Montini Marcella , Ghigo Ezio
Published: May 2009

Objective

In acromegaly, 25–50% of patients respond inadequately to conventional long-acting somatostatin analogue (SSA) therapy. Response may be improved by increasing SSA frequency or dose. This study evaluated the biochemical efficacy and safety of high-dose octreotide in patients with acromegaly.

Design

A 24-week prospective, multicentre, randomised, open-label trial conducted from 12 December 2005 to 23 October 2007 in patients with persistently uncontrolled acromegaly despite ≥6 month conventional SSA therapy.

Methods

Patients with ≥50% reduction in GH levels during previous SSA treatment were randomised to high-dose (60 mg/28 days) or high-frequency (30 mg/21 days) octreotide i.m. injection. Primary end-points were week 12 and 24 reduction in serum IGF1 and GH from baseline. Secondary end points included IGF1 normalisation and tumour shrinkage rates, and safety/tolerability evaluations.

Results

Significantly, more patients (10 out of 11) achieved week 24 IGF1 reduction in the high-dose than the high-frequency group (8 out of 15; P<0.05). In the high-dose group only, week-24 IGF1 values were significantly reduced (P=0.02) versus baseline. Normalisation of IGF1 occurred only with the high-dose regimen (4/11; P=0.02). Out of 14 patients experiencing adverse events, 5 reported drug-related gastrointestinal effects. No dose–response relationship was seen. Safety parameters were similar between treatment groups, apart from a slight decrease in HbA1c in the high-dose group only.

Conclusion

High-dose octreotide treatment is safe and effective (normalisation of IGF1 levels) in a subset of patients with active acromegaly inadequately controlled with long-term SSA. Individualised octreotide doses up to 60 mg/28 days may improve outcomes of SSA therapy.
Retrotransposon expression as a defining event of genome reprograming in fertilized and cloned bovine embryos
Authors: Bui L C , Evsikov A V , Khan D R , Archilla C , Peynot N , Hénaut A , Le Bourhis D , Vignon X , Renard J P , Duranthon V
Published: May 2009

Genome reprograming is the ability of a nucleus to modify its epigenetic characteristics and gene expression pattern when placed in a new environment. Low efficiency of mammalian cloning is attributed to the incomplete and aberrant nature of genome reprograming after somatic cell nuclear transfer (SCNT) in oocytes. To date, the aspects of genome reprograming critical for full-term development after SCNT remain poorly understood. To identify the key elements of this process, changes in gene expression during maternal-to-embryonic transition in normal bovine embryos and changes in gene expression between donor cells and SCNT embryos were compared using a new cDNA array dedicated to embryonic genome transcriptional activation in the bovine. Three groups of transcripts were mostly affected during somatic reprograming: endogenous terminal repeat (LTR) retrotransposons and mitochondrial transcripts were up-regulated, while genes encoding ribosomal proteins were downregulated. These unexpected data demonstrate specific categories of transcripts most sensitive to somatic reprograming and likely affecting viability of SCNT embryos. Importantly, massive transcriptional activation of LTR retrotransposons resulted in similar levels of their transcripts in SCNT and fertilized embryos. Taken together, these results open a new avenue in the quest to understand nuclear reprograming driven by oocyte cytoplasm.
Pyruvate prevents aging of mouse oocytes
Authors: Liu Na , Wu Yan-Guang , Lan Guo-Cheng , Sui Hong-Shu , Ge Li , Wang Jun-Zuo , Liu Yong , Qiao Tian-Wu , Tan Jing-He
Published: May 2009

Inhibiting oocyte aging is important not only for healthy reproduction but also for the success of assisted reproduction techniques. Although our previous studies showed that cumulus cells accelerated aging of mouse oocytes, the underlying mechanism is unknown. The objective of this paper was to study the effects of pyruvate and cumulus cells on mouse oocyte aging. Freshly ovulated mouse cumulus–oocyte complexes (COCs) or cumulus-denuded oocytes (DOs) were cultured in Chatot-Ziomek-Bavister (CZB) medium or COC-conditioned CZB medium supplemented with different concentrations of pyruvate before being examined for aging signs and developmental potential. Pyruvate supplementation to CZB medium decreased rates of ethanol-induced activation in both COCs and DOs by maintaining their maturation-promoting factor activities, but more pyruvate was needed for COCs than for DOs. Addition of pyruvate to the COC-conditioned CZB also alleviated aging of DOs. Observations on cortical granules, level of BCL2 proteins, histone acetylation, intracellular concentration of glutathione, and embryo development all confirmed that pyruvate supplementation inhibited aging of mouse oocytes. It is concluded that the aging of mouse oocytes, facilitated by culture in COCs, can be partially prevented by the addition of pyruvate to the culture medium.
Glycogen synthase kinase 3B in bovine oocytes and granulosa cells: possible involvement in meiosis during in vitro maturation
Authors: Uzbekova Svetlana , Salhab Mohamad , Perreau Christine , Mermillod Pascal , Dupont Joëlle
Published: May 2009

Glycogen synthase kinase 3 (GSK3) regulates cellular metabolism and cell cycle via different signalling pathways. In response to insulin and growth factors GSK3 is serine-phosphorylated and inactivated. We analysed GSK3B expression and activation in bovine cumulus cells (CC) and oocytes at different meiotic stagesin vitroin parallel with MAP kinases ERK (MAPK3/MAPK1) and p38 (MAPK14). GSK3B localised to cytoplasm in granulosa cells and in oocytes throughout folliculogenesis. In mature metaphase-II (MII) oocytes, GSK3B was concentrated to the region of midzone between the oocyte and the first polar body, as well as active phospho-Thr Aurora A kinase (AURKA). Duringin vitromaturation (IVM), in oocytes, phospho-Ser9-GSK3B level increased as well as phospho-MAPK3/MAPK1, while phospho-MAPK14 decreased. In CC, phospho-MAPK14 increased upon germinal vesicle breakdown (GVBD)/metaphase-I (MI) and then decreased during transition to MII. Administration of inhibitors of GSK3 activity (lithium chloride or 2′Z,3′E -6-bromoindirubin-3′-oxime) rapidly increased phospho-Ser9-GSK3B, and led to transient decrease of phospho-MAPK3/MAPK1 and to durable enhancing of phospho-MAPK14 in granulosa primary cell culture. GSK3 inhibitors during IVM diminished cumulus expansion and delayed meiotic progression. In cumulus, phospho-MAPK14 level was significantly higher in the presence of inhibitors, comparing with control, through the time of MI/MII transition. In oocytes, phospho-GSK3B was increased and phospho-MAPK3/MAPK1 was decreased before GVBD and oocytes were mainly arrested at MI. Therefore, GSK3B might regulate oocyte meiosis, notably MI/MII transition being the part of MAPK3/1 and MAPK14 pathways in oocytes and CC. GSK3B might be also involved in the local activation of AURKA that controls this transition.
Worlds of discourse in translation studies
Authors: Stolze Radegundis
Published: May 2009

This article addresses the issue that researchers in Translation Studies (TS), who apparently come from different worlds of discourse, seem to not really understand each other. Whereas in the liberal arts the focus is on the discussion and development of ideas and theories, empirical science concentrates on objects and data. This leads to differences in the academic conventions of scholarly communication and the construction of terminology. On the one hand, there is a preference for independent argumentation, not necessarily with exhaustive evidence; on the other hand, a systematic analysis of data using rigorous logical inference is expected. The paper describes the basic characteristics of academic writing in both worlds of discourse and presents a comparative survey of research skills needed in all fields of TS. The necessary skills, such as awareness of one’s background, critical reading, personal standpoint, consistency and logic, and explicitness in the presentation are valid for doing research in general. But they find different expression in scholarly writing according to the academic background.
Marked word order in the Qur’ān: Functions and translation
Authors: Elimam Ahmed
Published: May 2009

Word order in English is relatively fixed and the meaning of a sentence depends on the position of words in that sentence (Biber et al. 1999:898). Arabic, on the other hand, is more flexible as far as word order is concerned, thanks to its elaborate case marking and verb inflection systems. Moving elements within a sentence are called ‘foregrounding’, ‘inversion’, ‘preposing and postposing’ etc., in English and
al-Taqdīm wa al-Ta’khīr
in Arabic. The Qur’ān, rather than only using unmarked word orders, employs this linguistic feature of altering the order of elements within a clause for certain discursive functions. Drawing on the Arabic
balāghah
(Arabic art of eloquence) literature, this paper attempts, first, to establish some of the functions that are realised through using marked word order in the Qur’ān and, second, emphasise that word order in the Qur’ān is used to realise specific discursive functions, which should be taken into consideration when translating it into other languages, including English.
Info-promotional material discourse and its translation: The case of the Asturian tourist board texts
Authors: Valdeón Roberto
Published: May 2009

Tourism became the world’s first industry in the last decades of the 20th century. In this paper we examine the features of Spanish info-promotional materials, i.e. the official tourist brochures whose aim is to attract visitors and provide them with adequate information, as well as their English versions. We will assess four texts published by the Tourist Board of the Autonomous Government of the Principality of Asturias, in Northern Spain. The paper will examine the features (situational, interpersonal, ideational and textual) of the Spanish texts from a functional perspective, in an attempt to explore whether the information included is relevant for the communicative purposes of the texts. The next section will discuss the English translations, with particular reference to grammatical conventions, proper names and lexical choices. In the final discussion, we present some of the shortcomings of the texts and the problems deriving from certain cultural assumptions and linguistic choices. The paper concludes with some remarks about the need to involve specialists from various fields in the production of this type of materials.
War and interpreters
Authors: Takeda Kayoko
Published: May 2009

This paper attempts to shed light on issues of trust, control, ethics and identity concerning military interpreters who use their language skills against the country or people of their own cultural heritage. It examines linguists (translators and interpreters) who worked in military intelligence and operations during the Pacific War and the occupation of Japan, and military linguists involved in the current context of the “global war on terror”. Drawing on Cronin’s notion (2002, 2006) of heteronomous and autonomous interpreting systems, this paper discusses different sourcing avenues of military linguists during and after the Pacific War: Caucasian linguists trained at US military Japanese schools as autonomous, Japanese nationals locally hired for the occupation as heteronomous, andNisei(second-generation Japanese American) linguists as in-between. Parallels and comparisons are drawn between the ambiguous standing of thoseNiseilinguists and the situations of foreign-born US military interpreters and locally hired civilian interpreters in Iraq and Afghanistan. The complex and difficult challenges faced by military interpreters who utilize skills deeply rooted in their heritage against their own people or people of their cultural heritage should be visited in future discussion of government policies for recruiting, training and utilizing heritage language linguists in military settings.
A cognitive approach to the translation of metonymy-based humor
Authors: Rojo López Ana
Published: May 2009

This paper proposes an approach to the translation of humorous texts based on Cognitive Linguistics, one of the few linguistic theories which have attempted to unveil and understand the cognitive mechanisms that underlie the use of language for humorous purposes. More specifically, we argue that a model focused on the frames or knowledge structures activated in the text and on the metonymical mappings that guide humorous inferences may help us gain useful insights into the cognitive mechanisms used during humor production and understanding. This model is applied to the analysis of a number of examples from three different novels and their translations into Spanish:
Small World
by David Lodge,
Money
by Martin Amis, and
The Buddha of Suburbia
by Hanif Kureishi.The approach suggested here has centered on the metonymical patterns which have been most relevant to explain the humorous examples found in our corpus. In this sense, we have specifically focused on the analysis of four of the most productive types of metonymical mappings: part for whole, material for object, cause for effect
and producer for product
. Following Peirsman and Geeraerts’ (2006) prototypical organization of conceptual contiguity, these mappings have been classified into two different domains: a) contiguity in the spatial and material domain and b) contiguity in the domain of actions, events and processes. We will argue that such a model can guide translators, helping them to develop a systematic method to solve the problems implied in the translation of humor. In this way, it will be easier to adjust the comprehension mechanisms of the ST audience and those of the TT audience and elaborate a translation that achieves an equivalent effect to that of the ST.
A study of translatological dictionaries from the perspective of text linguistics
Authors: Min Fan , Wang He
Published: May 2009

This study examines translatological dictionaries from the perspective of text linguistics with a discussion of the close relationship between translatological dictionary studies and text linguistics. This is done to promote translatological dictionary studies and further the development of translation studies. The study demonstrates the textual and extra-textual constraints on the research and compilation of translatological dictionaries by discussing how seven criteria of textuality can be integrated into translatological dictionary studies. The study discusses the following three topics: (1) an understanding of the translatological dictionary and its research methodologies; (2) theoretical basis and significance of the translatological dictionary as text; and (3) the integration of the seven criteria of textuality into translatological dictionary studies.
Microbiological service for intensive care units in Hungary
Authors: Hajdú Edit , Benkő Ria , Matuz Mária , Pető Zoltán , Hegedűs Ágnes , Soós Gyöngyvér , Bogár Lajos , Nagy Erzsébet
Published: May 2009

Az intenzív osztályon az infekciók hatékony kezeléséhez elengedhetetlen a megbízható mikrobiológiai háttér, a mikrobiológiai leletek értékeléséhez infektológus vagy mikrobiológus szakember. A hazai felnőtt intenzív osztályok antibiotikum-politikájáról, mikrobiológiai hátteréről, infektológiai/mikrobiológiai konzultációs lehetőségeiről 97 kérdést tartalmazó kérdőív alapján készült felmérés. Az intenzív osztályok 62%-a (60/96) küldte vissza a kitöltött kérdőívet. A kérdésekre válaszoló osztályok 55%-ában működik az anyaintézetben mikrobiológiai laboratórium. Az antibiotikum-választáshoz a mikrobiológiai lelet szolgáltat elsősorban információt, míg a gyakori nosocomialis pneumoniák kórokozójának kimutatására szolgáló pozitív tenyésztésű alsó légúti minta eredménye hét közben 50%-ban, hétvégén <20%-ban érkezik optimális időben vissza az osztályokra. Az eredmények értelmezését segítő infektológus-mikrobiológus konzíliumra munkaidőben >90%-ban, munkaidőn kívül infektológus 70%-ban, mikrobiológus 55%-ban érhető el. Az osztályok közel fele veszi igénybe az infektológus, kevesebb mint egyharmada a mikrobiológus segítségét. A mikrobiológiai laboratóriumi diagnosztikai háttér messze nem optimális a magyarországi intenzív osztályok esetében, ezt a működési minimumfeltételek sem írják elő. Nagyon kevés a személyes szakmai konzultáció lehetősége is.
Reconstructive surgery of penile deformities and tissue deficiencies
Authors: Kelemen Zsolt
Published: May 2009

A hímvessző torzulatai és szövethiányos állapotai zavarják a közösülést vagy akár lehetetlenné tehetik. A dolgozat célja a különböző betegségek összefoglalása klinikai megjelenésük és kórfolyamataik alapján, a műtéti módszerek meghatározása és eredményességük bemutatása gyakorlatunkban. A hypo- és epispadiasis ellátása rendszerint gyermekkorban megtörténik, de a sikertelen műtétek utáni torzulatok a húgycső, a bőr és esetlegesen a barlangos testek helyreállítását is szükségessé tehetik. Az induratio penis plastica (Peyronie-kór) és a penis fractura utáni görbület a tunica albuginea műtétét igényli. A plakksebészet irha-, hereburok- vagy vénagraft felhasználását jelenti, a legjobb eredményeket azonban a Heinecke–Mikulitz-elv szerinti ellenoldali rövidítéssel érték el. Szövethiányos állapotokat és görbületeket észleltek olyan nekrotizáló, gyulladásos folyamatok után, mint a Fournier-gangraena vagy az idült bőrgyulladás. A bőrhiányokat lebenyekkel és graftokkal pótolták. Az erectilis diszfunkció kezelésében alkalmazott intracavernosus injekciók után a hímvessző súlyos tályogos szövetpusztulását vagy heges torzulatát észlelték. A helyreállító műtét lehetőségei ezen esetekben meglehetősen korlátozottak. Új feladatként jelentkezett a hímtag zsírgranulomájának eltávolítása. A bőrpótlás legjobb módszerének a hímvessző átmeneti herezacskóba bújtatása bizonyult.
Current status of treatment for early-stage invasive breast cancer
Authors: Kásler Miklós , Polgár Csaba , Fodor János
Published: May 2009

Az emlőrák a nők leggyakoribb rákos megbetegedése. Évente több mint egymillió nő betegszik meg emlőrákban. Az emlőrákos morbiditás meredeken emelkedett a fejlett ipari országokban az utóbbi pár évtizedben, de a mortalitási ráta mostanában csökken. Az utóbbi a szervezett lakossági szűréseknek, a korszerű sebészi és sugárterápiás beavatkozásoknak és a hatékonyabb szisztémás kezeléseknek köszönhető. A fejlődés egyik legizgalmasabb területe az új terápiás szerek bevezetése a klinikai gyakorlatba. A célzott terápia (tirozinkinázok gátlása) rohamosan fejlődik. Korai (0./I./II. stádium) emlőrákban a daganatot műtéttel eltávolítják, és ezt követi az adjuváns kezelés. Az adjuváns kezelés célja a lokoregionális és távoli mikroszkopikus daganatdepozitok elpusztítása. A daganatos kiújulás kockázatának megbecsülésére prognosztikai faktorokat használunk. Az optimális individualizált kezelés meghatározását a prediktív faktorok segítik. A dolgozatban a korai emlőrák kezelésének jelenlegi helyzetét tárgyaljuk, beleértve az emlőmegtartó kezelést, a mastectomia utáni sugárkezelést, a hormon- és kemoterápiát, valamint a humán epidermális növekedési faktor receptor-2- (HER-2-) pozitív daganatok trastuzumabkezelését.