bluuebunny/crossref_metadata_2025 huggingface dataset:
Precision of Landmark Positioning on Digitized Models from Patients with Cleft Lip and Palate
Authors: Brief Jakob , Behle Jan H. , Stellzig-Eisenhauer Angelika , Hassfeld Stefan
Published: March 2006

Objective

To quantify the precision of landmark positioning on digitized casts of patients with unilateral cleft lip and palate.

Patients

Forty plaster models of newborns up to 8 months of age were selected from the archive of the Department of Orthodontics of the University of Heidelberg.

Material and Method

The plaster-cast models were digitized with a Micromeasure 70 three-dimensional laser scanner (Micromeasure, Bischoffen, Germany). The laser scanner used in this study operates with a precision of 0.15 mm on the x- and y-axes and 0.06 mm on the z-axis. In the intraobserver study, a single observer placed anatomical landmarks in four rounds, with at least 4 weeks between each round. In the interobserver study, four different observers each placed the same landmarks once. For the two different studies, an ideal location for each landmark was calculated by averaging the landmark positions of the four rounds or observers. The distance between each of the four landmark positions and the ideal landmark was measured.

Results

A 95% confidence interval for the landmark positioning error was calculated. For the intraobserver investigation, this error was 0.34 to 1.30 mm, and for the interobserver investigation it was 0.7 to 2.00 mm.

Conclusion

Because both investigations displayed comparable error intervals, it was concluded that different observers could perform landmark positioning for the same studies.
Determination of Facial Symmetry in Unilateral Cleft Lip and Palate Patients from Three-Dimensional Data: Technical Report and Assessment of Measurement Errors
Authors: Nkenke Emeka , Lehner Bernhard , Kramer Manuel , Haeusler Gerd , Benz Stefanie , Schuster Maria , Neukam Friedrich W. , Vairaktaris Eleftherios G. , Wurm Jochen
Published: March 2006

Objective

To assess measurement errors of a novel technique for the three-dimensional determination of the degree of facial symmetry in patients suffering from unilateral cleft lip and palate malformations.

Design

Technical report, reliability study.

Setting

Cleft Lip and Palate Center of the University of Erlangen-Nuremberg, Erlangen, Germany.

Patients

The three-dimensional facial surface data of five 10-year-old unilateral cleft lip and palate patients were subjected to the analysis. Distances, angles, surface areas, and volumes were assessed twice.

Main Outcome Measures

Calculations were made for method error, intraclass correlation coefficient, and repeatability of the measurements of distances, angles, surface areas, and volumes.

Results

The method errors were less than 1 mm for distances and less than 1.5° for angles. The intraclass correlation coefficients showed values greater than .90 for all parameters. The repeatability values were comparable for cleft and noncleft sides.

Conclusion

The small method errors, high intraclass correlation coefficients, and comparable repeatability values for cleft and noncleft sides reveal that the new technique is appropriate for clinical use.
Q289P Mutation in FGFR2 Gene Causes Saethre-Chotzen Syndrome: Some Considerations About Familial Heterogeneity
Authors: de Freitas Érika Cristina Lopes Burrone , Nascimento Sandra Regina Dantas , de Mello Maricilda Palandi , Gil-da-Silva-Lopes Vera Lúcia
Published: March 2006

Objective

To describe the first report on a three-generation family presenting typical features of Saethre-Chotzen syndrome, in which the Q289P mutation in the FGFR2 gene was detected.

Design

Dysmorphological evaluation was performed by a clinical geneticist. Direct sequencing of the polymerase chain reaction-amplified coding region of TWIST and screening for the P250R mutation in the FGFR3 gene were performed. Exons IIIa and IIIc of FGFR2 were sequenced also. The mutation was confirmed by both restriction-enzyme digestion and allelic-specific polymerase chain reaction.

Results

Neither TWIST gene analysis nor analysis of the P250R mutation on gene FGFR3 showed mutation within the coding sequence. A nucleotide change from CAG to CCG in exon IIIa of the FGFR2 gene that caused a Q289P mutation was detected, although exon IIIc in the propositus was normal. These same results were detected in his mother, but no other members of the kindred presented clinical features consistent with Saethre-Chotzen syndrome.

Conclusions

This mutation was previously reported in individuals with Crouzon and Jackson-Weiss syndromes. The FGFR2 mutation in the family with Saethre-Chotzen syndrome herein reported reinforces the idea of an interaction among TWIST and FGFR genes during development. Absence of the Q289P mutation in some affected individuals in this family is discussed.
Three-Dimensional Computed Tomography Cephalometry of Plagiocephaly: Asymmetry and Shape Analysis
Authors: Netherway D. J. , Abbott A. H. , Gulamhuseinwala N. , McGlaughlin K. L. , Anderson P. J. , Townsend G. C. , David D. J.
Published: March 2006

Objective

To investigate facial asymmetry associated with both deformational and synostotic plagiocephaly and to identify variables based on skeletal landmarks that distinguish the conditions and quantify severity.

Design

Retrospective, cross sectional.

Setting

Australian Craniofacial Unit, Adelaide.

Main Outcome Measures

Proportional differences between bilateral distances and principal component (PC) analysis of the skeletal landmarks.

Patients

The three-dimensional positions of 78 osseous landmarks were determined from computed tomography (CT) scans of 21 patients with deformational plagiocephaly (DP), 20 patients with unilateral coronal synostosis (UCS), and 2 patients with unilateral lambdoid synostosis (ULS).

Results

For both DP and UCS, significant asymmetry was found for the orbital depths, mandibular lengths, maxillary depths, zygomatic arch lengths, lateral base of the parietal bone, and the angle between the anterior and the posterior cranial base projected onto the axial plane. The small sample size for ULS precluded definitive statistical statements but allowed some useful comparisons with the other conditions. The first three PC scores were able to distinguish among the three conditions and which side was affected.

Conclusions

The asymmetry of the cranial base and facial structures, arising from localized abnormality or deformational forces in either the frontal or the occipital regions, can be quantified by a plethora of bilateral features or summarized by PC analysis.
The Genetic Basis of the Pierre Robin Sequence
Authors: Jakobsen Linda P. , Knudsen Mary A. , Lespinasse James , García Ayuso Carmen , Ramos Carmen , Fryns Jean-Pierre , Bugge Merete , Tommerup Niels
Published: March 2006

Objective

The Pierre Robin Sequence (PRS) is subgroup of the cleft palate population. As with the etiology of cleft lip or palate, the etiology of PRS is generally unknown. Some factors are suggestive of a genetic basis for PRS. The purpose of this study was to compare genetic information on PRS available in the literature and in a cytogenetic database to facilitate focused genetic studies of PRS.

Design

After searching Medline for “pierre robin and genetics,” the Mendelian Cytogenetics Network database for “robin” and “pierre robin,” and two reviews from the Human Cytogenetics Database for “cleft palate” and “micrognathia,” a comparison of the data and a search in Online Mendelian Inheritance in Man (OMIM) Gene Map was performed to identify relevant candidate genes.

Results

The findings revealed consistency to a certain degree to loci 2q24.1-33.3, 4q32-qter, 11q21-23.1, and 17q21-24.3. A search in the OMIM Gene Map provided many candidate genes for PRS in these regions. The GAD67 on 2q31, the PVRL1 on 11q23-q24, and the SOX9 gene on 17q24.3-q25.1 are suggested to be of particular importance.

Conclusion

Candidate loci and a few potential candidate genes for PRS are proposed from the present study. This may enable researchers to focus their effort in the studies of PRS.
Regional Anesthesia for Cleft Lip Repair: A Preliminary Study
Authors: Eipe Naveen , Choudhrie Ashish , Pillai A. Dildeep , Choudhrie Rajiv
Published: March 2006

Objective

To assess whether local anesthetic blockade of the infraorbital nerve may allow for cleft lip repair to be performed under regional anesthesia.

Method

Twenty patients above 12 years of age with cleft lip (7 females and 13 males) were enrolled. Careful preoperative counseling was given. Bilateral infraorbital block was performed (extraoral approach) with 10 mL of equal volumes of 2% lidocaine with 1:200,000 adrenaline and 0.5% bupivacaine. The point of entry was the intersection of a vertical line through the pupil of the eye (in the neutral position) and a horizontal line through the ala of the nose. The needle was directed medially and cephalad until the infraorbital foramina was reached and 2 mL was injected. Through the same point of entry, but directed medially (toward the ala), 1 mL was injected followed by a 2-mL injection caudally and medially (into the lip).

Results

The block was successful in all patients without complication. The surgery was uneventful, lasting between 45 and 60 minutes. The postoperative duration of analgesia was between 6 and 24 hours (mean 16.5 ± 5.10 SD).

Conclusions

The nerve supply of the cleft lip, our modification of the block, and possible problems with this technique are discussed. This study confirms the utility of this block for postoperative analgesia. Further studies are required to apply this innovative, safe, and economical modification of anesthesia for cleft lip surgery.
Phonetic Description of Babbling in Danish Toddlers Born with and without Unilateral Cleft Lip and Palate
Authors: Willadsen Elisabeth , Albrechtsen Helle
Published: March 2006

Objective

To investigate prelinguistic vocalization sequences of 1-year-old children with and without cleft lip and palate.

Design

Prospective study.

Participants

Thirty-eight children born with unilateral cleft lip and palate and 36 control children born without clefts. The cleft children had the lip, soft palate, and posterior part of the hard palate repaired at 4 months of age. The lip was closed ad modum Millard, the nose was corrected according to McComb, and the soft palate was closed with a posteriorly based vomer flap.

Methods

Data were obtained from a clinical visit during which the baby played with the mother. Video recordings were transcribed and analyzed concerning (1) the frequency of occurrence of vocalization sequences, (2) the frequency of occurrence of contoids and vocoids, (3) the contoids’ place and manner of articulation, and (4) the percentage of children who entered the canonical babbling stage.

Results

No significant differences were observed between the cleft and control groups concerning frequency of occurrence of vocalization sequences, contoids, or vocoids. Structural differences between the groups seem to influence the contoid inventory, with a higher frequency of occurrence of nasal contoids and a smaller frequency of occurrence of alveolar contoids in the cleft group. Canonical babbling was achieved by most children in both groups, and no significant difference was found between the groups.

Conclusions

Early closure of the soft palate seems to have a positive influence on the prelinguistic development of children with cleft palate.
Installing rock anchorages in a nuclear-licensed dock site
Authors: Chapman M. , Parrish S. , Solley K.
Published: March 2006

This paper reports on and presents details of rock anchorages installed within the nuclear-licensed site at Devonport Royal Dockyard. For those upgrade works undertaken since 1997, when the dockyard was sold to Devonport Management Ltd, the paper describes the design and installation considerations for the selection of rock anchorages. The selection process involved considerations of examination, inspection, maintenance and testing (EIMT) requirements to meet nuclear safety criteria, anchorage capacity and cost. Bar anchorages were generally adopted, but where their capacity was less than the required working load strand anchorages were used.
A geotechnical classification system for coal ashes
Authors: Prakash K. , Sridharan A.
Published: March 2006

Most of the existing soil classification systems make use of the plasticity chart for classifying fine-grained soils and some coarse-grained soils as well. They cannot classify those granular materials that are non-plastic through appropriate group symbols indicative of their non-plastic nature without any ambiguity. Coal ashes, consisting of fly ash (known as pulverised fuel ash in the UK), bottom ash and pond ash, are produced in large quantities and are occasionally used in geotechnical applications. As they are non-plastic materials, the existing classification systems fail to classify them appropriately. This paper discusses this issue in detail. A classification system for coal ashes that are essentially non-plastic is formulated and proposed in this paper. It is shown through illustrative examples that the coal ashes can be classified easily and without any ambiguity using the proposed system.
Sample disturbance effects on medium plasticity clay/silt
Authors: Long M.
Published: March 2006

Practising engineers designing civil engineering works on soft clay usually assume that laboratory tests on normal piston tube sampling will at worst give conservative design parameters. Indeed most research into sampling disturbance effects on soft clays has proven that use of poor-quality tube samplers ultimately leads to lower undrained strength, stiffness and preconsolidation stress than actually exist in situ. There is some evidence to suggest that this may not hold true for ‘intermediate’ clay/silts or laminated soils. These issues were investigated for the Athlone laminated clay/silt, and it was found that tube sampling disturbance leads to increase in stiffness and undrained strength, and induces a strong tendency for dilatant behaviour post peak. These findings were made by comparing tube sample data with data from high-quality Sherbrooke block sampling and full-scale field trials. From the results of this investigation, and from comparisons with other soils, it is concluded that undrained tube sampling strains have only a minor influence, and that the behaviour of these medium plasticity clay/silts is due mainly to partially drained tube insertion process. Engineers dealing with soft ‘intermediate’ or laminated soils need to assess the laboratory-derived parameters carefully, especially when the clay content is less than about 40% and the plasticity index is less than 20%.
Voltammetric Studies and Determination of Levodopa and Carbidopa in Pharmaceutical Products
Authors: Quintino Maria Socorro Maia , Yamashita Miyuki , Angnes Lúcio
Published: March 2006

In this paper, the possibility of analyzing levodopa and carbidopa by differential pulse voltammetry (DPV) utilizing a glassy carbon electrode in 0.1 mol L−1 HClO4 is reported. Cyclic voltammograms of levodopa show a redox couple with anodic and cathodic peak potentials at 0.58 V and 0.52 V (vs. Ag/AgCl), respectively. For carbidopa, there are two oxidation waves with maximum currents at 0.53 V and 1.02 V, without any cathodic counterpart at slow enough scan rate. Since in such conditions, the oxidation product of carbidopa does not undergo reduction, it is possible to analyze levodopa without interference. On the other hand, carbidopa can be determined between 0.85 V and 1.1 V in the presence of levodopa, coating the electrode with a Nafion film, which is selective for carbidopa. The developed methodology was applied to two different commercial samples of pharmaceutical products. The obtained data were compared with the results of the analysis by high performance liquid chromatography (HPLC) with UV detection, showing good correlation (relative errors changing between 0.4% and 3.5%) and absence of interference of the other components that accompanied the pharmaceuticals.
Acetalization and thioacetalization of cabonyl compounds: A case study based on global and local electrophilicity descriptors
Authors: Roy Ram Kinkar , Usha V. , Patel Bhisma K. , Hirao Kimihiko
Published: March 2006

Acetalization of benzaldehyde and substituted benzaldehydes (containing both electron‐donating and electron‐withdrawing groups) is explained qualitatively on the basis of global electrophilicity descriptor, w, as proposed by Parr and coworkers (J Am Chem Soc 1999, 121, 1922). The generated values of w can explain qualitatively the preferential electrophilic addition, and hence, the yield of acetalization obtained in an earlier experimental study carried by Patel and coworkers (J Org Chem 2002, 67, 5842). The present study also reveals that although both steric and electronic factors affect the yield, only later can be taken care of by w. In the case of a competitive formation of cyclic acetals and cyclic thioacetals from a reaction mixture containing p‐hydroxybenzaldehyde, p‐nitrobenzaldehyde, 1,2‐ethanediol (i.e., glycol), and 1,2‐ethanedithiol, the relative experimental yields (Org Biomol Chem 2004, 2, 1670) could be explained from the difference of the global electrophilicity values between aldehydes and acetalizing agents in the same line of arguments of Maynard et al. (Proc Natl Acad Sci USA 1998, 95, 11578). © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 773–780, 2006
Caspase‐dependent cleavage of 170‐kDa P‐glycoprotein during apoptosis of human T‐lymphoblastoid CEM cells
Authors: Mantovani Irina , Cappellini Alessandra , Tazzari Pier Luigi , Papa Veronica , Cocco Lucio , Martelli Alberto M.
Published: March 2006

Multidrug resistance (MDR) mediated by the drug efflux protein, 170‐kDa P‐glycoprotein (P‐gp), is one mechanism that tumor cells use to escape cell death induced by chemotherapeutic drugs. Moreover, evidence suggests that cell lines expressing high levels of 170‐kDa P‐gp are less sensitive to caspase‐mediated apoptosis induced by a wide range of death stimuli, including Fas ligand, tumor necrosis factor, and ultraviolet irradiation. However, the fate of 170‐kDa P‐gp during apoptosis is unknown. In this study, we demonstrate for the first time that 170‐kDa P‐gp is cleaved during apoptosis of VBL100 human T‐lymphoblastoid CEM cells. Apoptotic cell death was induced by LY294002 (a pharmacological inhibitor of the phosphoinositide 3‐kinase/Akt survival pathway), H2O2, and Z‐LEHD‐FMK (a caspase‐9 inhibitor which has been recently reported to induce apoptosis in CEM cells). Using an antibody to a common epitope present in both the third and the sixth extracellular loop of P‐gp, two cleavage products were detected, with an apparent molecular weight of 80 and 85 kDa. DEVD‐FMK (a caspase‐3 inhibitor), but not VEID‐CHO (a caspase‐6 inhibitor), blocked 170‐kDa P‐gp cleavage. Recombinant caspase‐3 was able to cleave in vitro 170‐kDa P‐gp yielding two fragments of equal size to those generated in vivo. Considering the size of the cleaved fragments and their reactivity with antibodies, which recognize either the N‐half or the C‐half region of the protein, it is conceivable that the cleavage occurs intracytoplasmically. Since 170‐kDa P‐gp has been reported to counteract apoptosis, its cleavage may be a mechanism aimed at blocking an important cell survival component. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.
Mutational analysis of the cell cycle inhibitor Kip1/p27 in childhood leukemia
Authors: Markaki E.‐A. , Stiakaki E. , Zafiropoulos A. , Arvanitis D.A. , Katzilakis N. , Dimitriou H. , Spandidos D.A. , Kalmanti M.
Published: March 2006

Background

Cyclin‐dependent kinases (CDKs) and cyclins, their regulatory subunits, govern cell‐cycle progression in eukaryotic cells. Kip1/p27 is the main cyclin‐dependent kinase inhibitor, which arrests cell division inhibiting G1–S transition. Kip1/p27 seems to play a critical role in the pathogenesis of several human malignancies and its lower expression has been shown to correlate with a poor prognosis in adult solid tumors.

Methods

Bone marrow blasts from 49 children with leukemia, 37 acute lymphoblastic leukemia (ALL), and 12 acute myeloid leukemia (AML) were studied. Exon 3 of Kip1/p27 was amplified using the polymerase chain reaction technique (PCR). Single strand conformational polymorphism and heterodouplex analysis were performed to detect DNA sequence with altered conformations and were subsequently sequenced to document mutations.

Results

Mutations in Kip1/p27 gene were detected in 2 out of 3 T‐ALL, 6 out of 12 AML patients, and only 1 out of 34 B lineage ALL cases. Although the patient groups are small, a highly significant relation of the mutation status with the type of leukemia (P = 0.0037) and the risk group according to treatment protocols (P = 0.00021) was estimated. A statistically significant difference in the white blood count was observed (P = 0.019) between the mutated and non‐mutated patient groups although no statistically significant association of the mutation status with the hemoglobin and platelets values, karyotype, age, sex, disease progression, and outcome was determined.

Conclusions

Based upon these results, the Kip1/p27 mutations should be considered for further prospective testing as an additional parameter for risk stratification and treatment of childhood leukemia. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.
Leydig cell tumor after treatment for Ewing's sarcoma
Authors: Butros Linda J. , Phillip Shaji , Chou Alexander , Meyers Paul A. , Huvos Andrew G. , Healey John H. , Russo Paul , Gorlick Richard G.
Published: March 2006

Leydig cell tumors account for 3% of testicular tumors and have never been reported after treatment for Ewing's sarcoma. We report the unusual occurrence of a patient who developed a Leydig cell tumor of the testis 18 years after successful treatment for Ewing's sarcoma. Additional monitoring for second malignancies may become appropriate as long‐term survival continues to improve for patients with Ewing's sarcoma. Pediatr Blood Cancer 2007;49:1008–1010. © 2006 Wiley‐Liss, Inc.
Polymerization compounding of HDPE/Kevlar composites. I. Morphology and mechanical properties
Authors: Rajabian Mahmoud , Dubois Charles
Published: March 2006

The aim of this work is to perform the polymerization compounding to improve the properties of Kevlar/PE composites. The approach consists in involving the surface of a reinforcement in a polymerization process of a polymer to be used either as a matrix in the final composite or as a special surface treatment to enhance solid/polymer interface properties in the composite. The polymerization compounding process is illustrated here with the polyaramid fibers as reinforcements and polyethylene as a matrix. The number of active sites on the fiber surface, initially insufficient to anchor the catalyst, were increased by a hydrolysis reaction prior to the polymerization. The anchored catalyst was subsequently used to conduct the Ziegler–Natta polymerization reaction of ethylene. The modified fibers were incorporated into the polyethylene resin to produce composites at fiber concentrations as high as 15 wt%. The morphology of the fibers and the composites was tested using electron microscopy. Finally, the mechanical properties of the composites (in impact and tensile tests) were measured to characterize the properties of model composites. Polym. Compos. 27:129–137, 2006. © 2006 Society of Plastics Engineers.
The Human Liver Proteome Project (HLPP) Workshop during the 4th HUPO World Congress
Authors: Zheng Junjie , Gao Xue , Beretta Laura , He Fuchu
Published: March 2006

The Human Liver Proteome Project (HLPP) is the first initiative of the Human Proteome Organisation (HUPO) to target a human organ/tissue and aims at the establishment of a biological atlas of the liver to advance our understanding of liver functions and to provide the tools to develop new diagnostics and therapeutics for liver diseases. The major achievements of HLPP during its pilot phase (2003–2005) were presented during a one‐day workshop held on August 27, 2005, immediately prior to the 4th HUPO World Congress in Munich, Germany. These include (i) the participation of a large number of laboratories worldwide and the initiation of international research collaborations; (ii) the establishment of a management infrastructure and (iii) the development of standard operating procedures and the generation and collection of a first set of expression profile data. A summary of the workshop was subsequently presented by Professor Fuchu He, the Chair of this initiative, during the HUPO 4th Annual World Congress.
Book Review: Proteomics in Cancer Research. By Daniel C. Liebler (Ed.)
Authors: Kovarova Hana
Published: March 2006

No abstracts.
Perfluorous Solid‐Phase Organic Synthesis (PF‐SPOS) and IRORI Technology for Combinatorial Chemistry
Authors: Ortega Alberto , Erra Montserrat , Navarro Eloísa , Roberts Richard S. , Fernández‐Forner Dolors
Published: March 2006

The use of perfluorous solvents in combination with IRORI technology and its application for the synthesis of combinatorial libraries is described. This methodology shows a clear advantage over standard solid‐phase synthesis in IRORI MiniKans, because the large amounts of reagents and solvents required for IRORI can be substantially reduced. Herein we report a comparative study for the synthesis of some dihydroquinazolines and quinazolinones derivatives, using standard SPOS conditions and perfluorous solvent conditions (PF‐SPOS) in IRORI reactors. Yields of products were normally greater with perfluorous solvents than those observed with standard SPOS conditions. The results obtained by the use of this convenient strategy for the solid‐phase preparation of a 384‐membered library of dihydroquinazolines and quinazolinones are also shown
Information Gain versus State Disturbance for a Single Qubit
Authors: Banaszek Konrad
Published: March 2006

The trade-off between the information gain and the state disturbance is derived for quantum operations on a single qubit prepared in a uniformly distributed pure state. The derivation is valid for a class of measures quantifying the state disturbance and the information gain which satisfy certain invariance conditions. This class includes in particular the Shannon entropy versus the operation fidelity. The central role in the derivation is played by efficient quantum operations, which leave the system in a pure output state for any measurement outcome. It is pointed out that the optimality of efficient quantum operations among those inducing a given operator-valued measure is related to Davies' characterization of convex invariant functions on hermitian operators.
On Partially Entanglement Breaking Channels
Authors: Chruściński Dariusz , Kossakowski Andrzej
Published: March 2006

Using well known duality between quantum maps and states of composite systems we introduce the notion of Schmidt number for a quantum channel. It enables one to define classes of quantum channels which partially break quantum entanglement. These classes generalize the well known class of entanglement breaking channels.
Neural Structures Using the Eigenstates of a Quantum Harmonic Oscillator
Authors: Rigatos Gerasimos , Tzafestas Spyros
Published: March 2006

The main result of the paper is the use of orthogonal Hermite polynomials as the basis functions of feedforward neural networks. The proposed neural networks have some interesting properties: (i) the basis functions are invariant under the Fourier transform, subject only to a change of scale, (ii) the basis functions are the eigenstates of the quantum harmonic oscillator, and stem from the solution of Schrödinger's diffusion equation. The proposed feed-forward neural networks demonstrate the particle-wave nature of information and can be used in nonparametric estimation. Possible applications of the proposed neural networks include function approximation, image processing and system modelling.
Stability Analysis of an Endoreversible Heat Engine with Stefan-Boltzmann Heat Transfer Law Working in Maximum-Power-Like Regime
Authors: Chimal-Eguía J. C. , Barranco-Jiménez M. A. , Angulo-Brown F.
Published: March 2006

A local stability study of an endoreversible Stefan-Boltzmann (SB) engine, working in a maximum-power-like regime, is presented. This engine consists of a Carnot engine that exchanges heat with heat reservoirs T1 and T2, (T 1 > T2) through a couple of thermal links, both having the same conductance g. In addition, the working fluid has the same heat capacity C in the two isothermal branches of the cycle. From the local stability analysis we conclude that the SB engine is stable for every value of g, C and τ = T2/T1. After a small perturbation, the system decays to the steady state with either of two different relaxation times; both being proportional to C/g, and τ. Finally, when we plot some of the thermodynamic properties in the steady state versus τ, we find how an increment of τ can improve the stability of the system, at the same decreasing the efficiency and the power of the system. This suggests a compromise between the stability and the energetic properties of the engine driven by τ.
Ecological Optimization Performance of An Irreversible Quantum Otto Cycle Working with an Ideal Fermi Gas
Authors: Wu Feng , Chen Lingen , Sun Fengrui , Wu Chih , Guo Fangzhong , Li Qing
Published: March 2006

The model of an irreversible Otto cycle using an ideal Fermi gas as the working fluid, which is called as the irreversible Fermi Otto cycle, is established in this paper. Based on the equation of state of an ideal Fermi gas, the ecological optimization performance of an irreversible Fermi Otto cycle is examined by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the exergy output and exergy loss (entropy production) of the cycle. The relationship between the ecological function E and the efficiency η is studied. Three special cases are discussed in detail. The results obtained herein may reveal the general performance characteristics of the irreversible Fermi Otto cycle.
Phase-Space Approach to Berry Phases
Authors: Chruściński Dariusz
Published: March 2006

We propose a new formula for the adiabatic Berry phase which is based on phase-space formulation of quantum mechanics. This approach sheds a new light onto the correspondence between classical and quantum adiabatic phases — both phases are related with the averaging procedure: Hannay angle with averaging over the classical torus and Berry phase with averaging over the entire classical phase space with respect to the corresponding Wigner function.
Entropies of Mixing (EOM) and the Lorenz Order
Authors: Lavenda B. H.
Published: March 2006

Polynomial nonadditive, or pseudo-additive (PAE), entropies are related to the Shannon entropy in that both are derived from two classes of parent distributions of extreme-value theory, the Pareto and power distributions. The third class is the exponential distribution, corresponding to the Shannon entropy, to which the other two tend as their shape parameters increase without limit. These entropies all belong to a single class of entropies referred to as EOM. EOM is defined as the normalized difference between the dual of the Lorentz function and the Lorenz function. Sufficient conditions for majorization involve finding a separable, Schur-concave function, like the EOM, which increases as the distribution becomes more uniform or less spread out. Lorenz ordering has been associated to the degree in which the Lorenz curve is bent. This criterion is valid for tail distributions, and fails in the case where the distribution is limited on the right. EOM provide criteria for inequality in the Lorenz ordering sense: In the Pareto case, an increase in the shape parameter implies a decrease in inequality and the EOM decreases, whereas for the power distribution an increase in the shape parameter corresponds to an increase in inequality leading to an increase in the EOM. An analogy is drawn between Gauss' invariant distribution for the probability of the fractional part of a continued fraction and the area criterion in Lorenz ordering, analogous to the Gini index criterion. The tendency to approach the invariant distribution, as the number of partial quotients increases without limit, is shown to be analogous to the tendency to approach the invariant area, as the shape parameters increase without limit.
Geometric Entropies of Mixing (EOM)
Authors: Lavenda B. H.
Published: March 2006

Trigonometric and trigonometric-algebraic entropies are introduced and are given an axiomatic characterization. Regularity increases the entropy and the maximal entropy is shown to result when a regular n-gon is inscribed in a circle. A regular n-gon circumscribing a circle gives the largest entropy reduction, or the smallest change in entropy from the state of maximum entropy, which occurs in the asymptotic infinite n-limit. The EOM are shown to correspond to minimum perimeter and maximum area in the theory of convex bodies, and can be used in the prediction of new inequalities for convex sets. These expressions are shown to be related to the phase functions obtained from the WKB approximation for Bessel and Hermite functions.
Separability of Mixed Quantum States: Linear Contractions and Permutation Criteria
Authors: Horodecki Michał , Horodecki Paweł , Horodecki Ryszard
Published: March 2006

Recently, a powerful separability criterion was introduced by O. Rudolf in [5] and by K. Chen et al. in [6] — basing on realignment of elements of density matrix. Composing the main idea behind the above criterion and the necessary and sufficient condition in terms of positive maps, we provide a characterization of separable states by means of linear contractions. The latter need not be positive maps. We extend the idea to multipartite systems, and find that, somewhat suprisingly, partial realigment (unlike partial transposition) can detect genuinely tri-parite entanglement. We generalize it by introducing a family of so called permutation separability criteria for multipartite states. Namely, any permutation of indices of density matrix written in product basis leads to a separability criterion. Partial transpose and realignment criterion are special cases of permutation criteria.
Clinical profile, contemporary management and one‐year mortality in patients with severe acute heart failure syndromes: The EFICA study☆
Authors: Zannad Faiez , Mebazaa Alexandre , Juillière Yves , Cohen‐Solal Alain , Guize Louis , Alla François , Rougé Pierre , Blin Patrick , Barlet Marie‐Hélène , Paolozzi Laurence , Vincent Catherine , Desnos Michel , Samii Kamran ,   for the EFICA Investigators
Published: March 2006

Background:

Little is known about the epidemiology of acute decompensated heart failure (ADHF) in patients admitted to intensive and coronary care units (ICU/CCU). Observational data may improve disease management and guide the design of clinical trials.

Aims:

EFICA is an observational study of the clinical profile, management and survival of ADHF patients admitted to ICU/CCU.

Methods:

The study included 599 patients admitted to 60 ICU/CCUs across France. Relevant data was recorded during hospitalisation. Survival was assessed at 4 weeks and 1 year.

Results:

The main cause of ADHF was ischaemic heart disease (61%); 29% of patients had cardiogenic shock. Mortality was 27.4% at 4 weeks and 46.5% at 1 year, increasing to 43.2% and 62.5%, respectively, when including pre‐admission deaths. Shock patients had the highest [57.8% vs. 15.2% without shock (p<0.001)] and patients with hypertension and pulmonary oedema had the lowest 4‐week mortality: (7%). Pre‐admission NYHA class III–IV heart failure, not initial clinical presentation, influenced 1‐year mortality.

Conclusion:

ADHF is a heterogeneous syndrome. Based on initial clinical presentation, three entities with distinct features and outcome may be described: cardiogenic shock, pulmonary oedema with hypertension, and ‘decompensated’ chronic heart failure. This should be taken into account in future observational studies, guidelines and clinical trials.
Familial inflammatory dilated cardiomyopathy
Authors: Portig Irene , Wilke Andreas , Freyland Matthias , Wolf Markus‐Joachim , Richter Anette , Ruppert Volker , Pankuweit Sabine , Maisch Bernhard
Published: March 2006

Background

Systematic family screening has recently identified dilated cardiomyopathy as an inherited disorder in up to 30% of cases. Mutations in genes encoding proteins responsible for myocardial architecture have been identified, but additional pathophysiological mechanisms including inflammatory reactions have been proposed.

Aims

Identification and characterization of familial DCM, where at least one affected family member fulfils the criteria for inflammatory DCM may lead to a better understanding of the aetiology and pathogenesis of (inflammatory) DCM.

Methods and results

Ten families were examined. In six families, clinical characteristics and mode of inheritance were compatible with pure fDCM, fDCM with conduction defect and autosomal recessive fDCM. In four families, (auto‐)immune features were diagnosed in affected and non‐affected family members.

Conclusions

Familial DCM with an inflammatory component was identified as a specific subgroup of familial DCM. In most cases, the inflammatory process seems to modify, i.e. aggravate, the “classic, cytoskeletopathic” familial DCM, but in some, especially when taking clinical and genetic aspects into account, inflammatory (auto‐)immune features can be addressed as the leading pathogenetic principle. Further elucidation of these families may provide a better insight into pathophysiologic processes and may aid in the development of specific therapeutic strategies.
Adult attachment variables predict depression before and after treatment for chronic pain
Authors: Meredith Pamela J. , Strong Jenny , Feeney Judith A.
Published: March 2006

The complex relationship between chronic pain and depression has long been of clinical and empirical interest. Although attachment theory has been described as a “theory of affect regulation”, and has been lauded as a developmental framework for chronic pain, surprisingly little research specifically considers the links between adult attachment variables and pain‐related depression. A sample of 99 participants with chronic pain of non‐cancer origin was evaluated before and after pain rehabilitation. Results demonstrated that two attachment dimensions (comfort with closeness and relationship anxiety) were related to pre‐ and post‐treatment depression. Of particular interest was the finding that comfort with closeness was the unique predictor of lower levels of post‐treatment depression, usurping pain intensity and pre‐treatment depression. These results are discussed in terms of clinical implications, and suggest that adult attachment theory may prove a valuable perspective in pain treatment programs.
Role of the carboxyl terminal stop transfer sequence of UGT1A6 membrane protein in ER targeting and translocation of upstream lumenal domain
Authors: Ouzzine M. , Barré L. , Netter P. , Magdalou J. , Fournel-Gigleux S.
Published: March 2006

We investigated the role of the stop transfer sequence of human UGT1A6 in ER assembly and enzyme activity. We found that this sequence was able to address and translocate the upstream lumenal domain into microsomal membranes in vitro co‐ and posttranslationally. The signal activity of this sequence was further demonstrated in HeLa cells by its ability to target and maintain the CD4 protein deleted from both the N‐terminal signal peptide and C‐terminal transmembrane domain into the ER. We showed that total or partial deletion of the stop transfer sequence of UGT1A6 severely impaired enzyme activity highlighting its importance in both membrane assembly and function.
Erythropoietin activates caspase‐3 and downregulates CAD during erythroid differentiation in TF‐1 cells – A protection mechanism against DNA fragmentation
Authors: Lui Julian Chun-Kin , Kong Siu-Kai
Published: March 2006

The involvement of caspase‐3 and its failure in the induction of DNA fragmentation during erythropoiesis were investigated with TF‐1 cells. During erythroid differentiation, caspase‐3 activation and cleavage of caspase‐3 substrates such as ICAD (inhibitor of caspase‐activated DNase) were detected without concomitant phosphatidyl‐serine (PS) externalization and DNA fragmentation. These observations are in contrast to our understanding that DNA is degraded by CAD (caspase‐activated DNase) when ICAD is cleaved by caspase‐3. Our study demonstrates that CAD is downregulated at the mRNA and protein level during the erythroid differentiation in TF‐1 cells. This provides a mechanism for the first time how cells avoid DNA fragmentation with activated caspase‐3.
Skl, a novel choline‐binding N‐acetylmuramoyl‐l‐alanine amidase of Streptococcus mitis SK137 containing a CHAP domain
Authors: Llull Daniel , López Rubens , García Ernesto
Published: March 2006

The skl gene from Streptococcus mitis SK137 encodes a peptidoglycan hydrolase (Skl) that has been purified and biochemically characterized. Analysis of the degradation products obtained by digestion of pneumococcal cell walls with Skl revealed that this enzyme is an N‐acetylmuramoyl‐l‐alanine amidase (EC 3.5.1.28), showing optimum activity at 30 °C and at a pH of 6.5. Skl is a unique member of the choline‐binding family of proteins since it contains a cysteine, histidine‐dependent amidohydrolases/peptidases (CHAP) domain. The CHAP domain of Skl showed homology to lysins of unknown especificity from a variety of streptococcal prophages. Skl represents the first characterized member of a new subfamily of CHAP‐containing choline‐binding proteins.
Level of M(IP)2C sphingolipid affects plant defensin sensitivity, oxidative stress resistance and chronological life‐span in yeast
Authors: Aerts An M. , François Isabelle E.J.A. , Bammens Leen , Cammue Bruno P.A. , Smets Bart , Winderickx Joris , Accardo Sabina , De Vos Dirk E. , Thevissen Karin
Published: March 2006

The antifungal plant defensin DmAMP1 interacts with fungal sphingolipids of mannosyldiinositolphosphorylceramide (M(IP)2C) class. We screened a Saccharomyces cerevisiae transposon (Tn) mutant library against DmAMP1 and identified one DmAMP1‐resistant mutant with the Tn inserted in the M(IP)2C biosynthesis gene IPT1 (DmTn11) and one DmAMP1‐hypersensitive mutant with the Tn inserted in rDNA (HsTnII). However, tetrad analysis pointed to HsTnII as a spontaneous mutant. Apparently, membranes of DmTn11 lack M(IP)2C, whereas membranes of HsTnII have increased M(IP)2C levels. In addition, DmTn11 and HsTnII are characterized by increased and reduced oxidative stress resistance/chronological life‐span (CL), respectively. A putative involvement of M(IP)2C in oxidative stress and CL in yeast is discussed.
The alternative pathway C20 Δ8‐desaturase from the non‐photosynthetic organism Acanthamoeba castellanii is an atypical cytochrome b5‐fusion desaturase
Authors: Sayanova Olga , Haslam Richard , Qi Baoxiu , Lazarus Colin M. , Napier Johnathan A.
Published: March 2006

A cDNA encoding a C20 Δ8‐desaturase was isolated from the free‐living soil amoeba, Acanthamoeba castellanii and functionally characterised by heterologous expression. The open reading frame of the A. castellanii C20 Δ8‐desaturase showed similarity to other microsomal front‐end desaturases, but the N‐terminal domain contained a variant form of the conserved heme‐binding motif in which H‐P‐G‐G is replaced by H‐P‐A‐G. Co‐expression of the A. castellani Δ8‐desaturase with the Isochrysis galbana Δ9‐elongase in transgenic Arabidopsis plants confirmed the activity observed in yeast and its role in the alternative pathway for C20 polyunsaturated fatty acid synthesis. Acyl‐CoA profiles of these transgenic plants revealed an unexpected accumulation of C20 fatty acids in the acyl‐CoA pool. This is the first report of an alternative pathway C20 Δ8‐desaturase from a non‐photosynthetic organism, and also the first report of a front‐end desaturase lacking the canonical cytochrome b
5 domain.
Yarrowia lipolytica possesses two plasma membrane alkali metal cation/H+ antiporters with different functions in cell physiology
Authors: Papouskova Klara , Sychrova Hana
Published: March 2006

The family of Nha antiporters mediating the efflux of alkali metal cations in exchange for protons across the plasma membrane is conserved in all yeast species. Yarrowia lipolytica is a dimorphic yeast, phylogenetically very distant from the model yeast Saccharomyces cerevisiae. A search in its sequenced genome revealed two genes (designated as YlNHA1 and YlNHA2) with homology to the S. cerevisiae NHA1 gene, which encodes a plasma membrane alkali metal cation/H+ antiporter. Upon heterologous expression of both YlNHA genes in S. cerevisiae, we showed that Y. lipolytica antiporters differ not only in length and sequence, but also in their affinity for individual substrates. While the YlNha1 protein mainly increased cell tolerance to potassium, YlNha2p displayed a remarkable transport capacity for sodium. Thus, Y. lipolytica is the first example of a yeast species with two plasma membrane alkali metal cation/H+ antiporters differing in their putative functions in cell physiology; cell detoxification vs. the maintenance of stable intracellular pH, potassium content and cell volume.
Blue fluorescent protein from the calcium‐sensitive photoprotein aequorin: Catalytic properties for the oxidation of coelenterazine as an oxygenase
Authors: Inouye Satoshi , Sasaki Satoko
Published: March 2006

Blue fluorescent protein from the calcium‐binding photoprotein aequorin (BFP‐aq) is a complex of Ca2+‐bound apoaequorin and coelenteramide, and shows luminescence activity like a luciferase, catalyzing the oxidation of coelenterazine with molecular oxygen. To understand the catalytic properties of BFP‐aq, various fluorescent proteins (FP‐aq) have been prepared from semi‐synthetic aequorin and characterized in comparison with BFP‐aq. FP‐aq has luciferase activity and could be regenerated into native aequorin by incubation with coelenterazine. The results from substrate specificity studies of FP‐aq using various coelenterazine analogues have suggested that the oxidation of coelenterazine by BFP‐aq in the luciferase reaction and the regeneration process to aequorin might involve the same catalytic site of BFP‐aq.
The temporal architecture of eukaryotic growth
Authors: Lloyd David , Murray Douglas B.
Published: March 2006

Coherence of the time structure of growing organisms depends on a metronome‐like orchestration. In a continuously perfused culture of Saccharomyces cerevisiae the redox state of the cell shows a temperature‐compensated oscillation manifest in respiratory cycles, which are measured by continuous and non‐invasive electrodes of probes such as dissolved oxygen and probes such as fluorometric NAD(P)H. Although the entire transcriptome exhibits low‐amplitude oscillatory behaviour, transcripts involved in the vast majority of metabolism, stress response, cellular structure, protein turnover, mRNA turnover, and DNA synthesis are amongst the top oscillators and their orchestration occurs by an intricate network of transcriptional regulators. Therefore cellular auto‐dynamism is a function of a large ensemble of excitable intracellular components of that self‐organized temporally and spatially that encompasses mitochondrial, nuclear, transcriptional and metabolic dynamics, coupled by cellular redox state.
Tau phosphorylation and aggregation in Alzheimer's disease pathology
Authors: Avila Jesús
Published: March 2006

In this article I shall review how tau phosphorylation and aggregation participates in Alzheimer's disease (AD) and other tauopathies. Tau, a microtubule associated protein, is the main component, in phosphorylated form, of the aberrant paired helical filaments found in AD. Tau is present in phosphorylated and aggregated form not only in AD, but in other pathologies (tauopathies). In this review, the phosphorylation of tau, its aggregation, and the possible relation between tau phosphorylation and aggregation is, briefly, described. Also, it is discussed the toxicity of modified tau. In addition, I propose a working model detailing the progression of tau pathologies.