bluuebunny/crossref_metadata_2025 huggingface dataset:
Complement Activation and Formation of the Membrane Attack Complex on Serogroup BNeisseria meningitidisin the Presence or Absence of Serum Bactericidal Activity
Authors: Drogari-Apiranthitou M. , Kuijper E. J. , Dekker N. , Dankert J.
Published: July 2002

Encapsulated meningococci are complement sensitive only in the presence of bactericidal antibodies by yet-unexplored mechanisms. The objective of this study was to investigate the involvement of major bacterial surface constituents on complement activation and membrane attack complex (MAC) formation on serogroup B meningococci in the presence or absence of antibody-dependent serum bactericidal activity (SBA). The strains used were the encapsulated H44/76, five of its variants differing in capsulation and expression of the class 1 porin (PorA), and its lipopolysaccharide (LPS)-deficient isogenic mutant (LPS−) pLAK33. Two normal sera, one with high SBA (SBA+) and one with no bactericidal activity (SBA−) against H44/76 as well as an a-γ-globulinemic serum were used for sensibilization of the bacteria. C3b and iC3b deposition on H44/76, its unencapsulated variant v24, and pLAK33 was similar in SBA+and SBA−serum, and no difference was present between the strains. MAC deposition on H44/76 was higher in SBA+serum than in SBA−serum and the a-γ-globulinemic serum. The amounts of C3b on H44/76, v24, and pLAK33 in the a-γ-globulinemic serum were also not different, indicating immunoglobulin G (IgG)- and LPS-independent complement activation. H44/76 PorA(+) and its PorA(−) variant and the v24 PorA(+) and its PorA(−) variant incubated in SBA−serum induced comparable amounts of MAC, despite their different serum sensitivities. Complement formation on the surface of the bacteria occurred almost exclusively via the classical pathway, but the considerable amounts of Bb measured in the serum indicated alternative pathway activation in the fluid phase. We conclude that complement deposition on meningococci is, for the most part, independent of classical pathway IgG and is not influenced by the presence of PorA or LPS on the meningococcal surface. Addition of an anti-PorA chimeric antibody to the nonbactericidal normal serum, while promoting a dose-related bacterial lysis, did not influence the amounts of C3b, iC3b, and MAC formed on the bacterial surface. These findings support the hypothesis that proper MAC insertion rather than the quantity of MAC formed on the bacterial surface is of importance for efficient lysis of meningococci.
The ArcB Sensor Kinase of
Escherichia coli
: Genetic Exploration of the Transmembrane Region
Authors: Kwon Ohsuk , Georgellis Dimitris , Lynch A. Simon , Boyd Dana , Lin E. C. C.
Published: July 2002

The Arc two-component signal transduction system of
Escherichia coli
regulates the expression of numerous operons in response to respiratory growth conditions. Cellular redox state or proton motive force (Δμ̄

H
+

) has been proposed to be the signal for the membrane-associated ArcB sensor kinase. This study provided evidence for a short ArcB periplasmic bridge that contains a His47. The dispensability of this amino acid, the only amino acid with a pK in the physiological range, renders the Δμ̄

H
+

model unlikely. Furthermore, results from substituting membrane segments of ArcB with counterparts of MalF indicate that the region does not play a stereospecific role in signal reception.
A Positive
cis
-Acting DNA Element Is Required for High-Level Transcription in
Chlamydia
Authors: Schaumburg Chris S. , Tan Ming
Published: July 2002

The spacer A/T region is a positive
cis
-acting DNA element that was identified in the
Chlamydia trachomatis
rRNA promoter region. We have now demonstrated that similar sequences in other chlamydial promoters are important for transcription. Substitution of candidate spacer A/T regions in four chlamydial promoters decreased transcription by partially purified
C. trachomatis
RNA polymerase in an in vitro transcription assay. Addition of a spacer A/T region to the
dnaK
promoter, which does not contain an identifiable spacer A/T region, increased transcription 16-fold. Transcription of
Escherichia coli
promoters by
C. trachomatis
RNA polymerase also appeared to be dependent on the spacer A/T region. However, the effect of the spacer A/T region on transcription by
E. coli
RNA polymerase was small. In summary, the spacer A/T region is a novel DNA element that is required for high-level transcription of many promoters by chlamydial RNA polymerase.
Rapid Discrimination among Dermatophytes,
Scytalidium
spp., and Other Fungi with a PCR-Restriction Fragment Length Polymorphism Ribotyping Method
Authors: Machouart-Dubach Marie , Lacroix Claire , de Chauvin Martine Feuilhade , Le Gall Isabelle , Giudicelli Catherine , Lorenzo Frédéric , Derouin Francis
Published: July 2002

Dermatomycoses are very common infections caused mainly by dermatophytes. Scytalidiosis is a differential mycological diagnosis, especially in tropical and subtropical areas. Since a culture-based diagnosis takes 2 to 3 weeks, we set up a PCR-restriction fragment length polymorphism (RFLP) method for rapid discrimination of these fungi in clinical samples. The hypervariable V4 domain of the small ribosomal subunit 18S gene was chosen as the target for PCR. The corresponding sequences from 19 fungal species (9 dermatophytes, 2
Scytalidium
species, 6 other filamentous fungi, and 2 yeasts) were obtained from databases or were determined in the laboratory. Sequences were aligned to design primers for dermatophyte-specific PCR and to identify digestion sites for RFLP analysis. The reliability of PCR-RFLP for the diagnosis of dermatomycosis was assessed on fungal cultures and on specimens from patients with suspected dermatomycosis. Two sets of primers preferentially amplified fungal DNA from dermatophytes (DH1L and DH1R) or from
Scytalidium
spp. (DH2L and DH1R) relative to DNA from bacteria, yeasts, some other filamentous fungi, and humans. Digestion of PCR products with
Eae
I or
Bam
HI discriminated between dermatophytes and
Scytalidium
species, as shown with cultures of 31 different fungal species. When clinical samples were tested by PCR-RFLP, blindly to mycological findings, the results of the two methods agreed for 74 of 75 samples. Dermatophytes and
Scytalidium
spp. can thus be readily discriminated by PCR-RFLP within 24 h. This method can be applied to clinical samples and is suited to rapid etiologic diagnosis and treatment selection for patients with dermatomycosis.
Detachment of Human Immunodeficiency Virus Type 1 from Germinal Centers by Blocking Complement Receptor Type 2
Authors: Kacani Laco , Prodinger Wolfgang M. , Sprinzl Georg M. , Schwendinger Michael G. , Spruth Martin , Stoiber Heribert , Döpper Susanne , Steinhuber Sabine , Steindl Franz , Dierich Manfred P.
Published: July 2002

After the transition from the acute to the chronic phase of human immunodeficiency virus (HIV) infection, complement mediates long-term storage of virions in germinal centers (GC) of lymphoid tissue. The contribution of particular complement receptors (CRs) to virus trapping in GC was studied on tonsillar specimens from HIV-infected individuals. CR2 (CD21) was identified as the main binding site for HIV in GC. Monoclonal antibodies (MAb) blocking the CR2-C3d interaction were shown to detach 62 to 77% of HIV type 1 from tonsillar cells of an individual in the presymptomatic stage. Although they did so at a lower efficiency, these antibodies were able to remove HIV from tonsillar cells of patients under highly active antiretroviral therapy, suggesting that the C3d-CR2 interaction remains a primary entrapment mechanism in treated patients as well. In contrast, removal of HIV was not observed with MAb blocking CR1 or CR3. Thus, targeting CR2 may facilitate new approaches toward a reduction of residual virus in GC.
Biochemical and Genetic Studies of the Initiation of Human Rhinovirus 2 RNA Replication: Purification and Enzymatic Analysis of the RNA-Dependent RNA Polymerase 3D
pol
Authors: Gerber Kinga , Wimmer Eckard , Paul Aniko V.
Published: July 2002

The replication of human rhinovirus 2 (HRV2), a positive-stranded RNA virus belonging to the
Picornaviridae
, requires a virus-encoded RNA polymerase. We have expressed in
Escherichia coli
and purified both a glutathione
S
-transferase fusion polypeptide and an untagged form of the HRV2 RNA polymerase 3D
pol
. Using in vitro assay systems previously described for poliovirus RNA polymerase 3D
pol
(J. B. Flanegan and D. Baltimore, Proc. Natl. Acad. Sci. USA 74:3677–3680, 1977; A. V. Paul, J. H. van Boom, D. Filippov, and E. Wimmer, Nature 393:280–284, 1998), we have analyzed the biochemical properties of the two different enzyme preparations. HRV2 3D
pol
is both template and primer dependent, and it catalyzes two types of synthetic reactions in the presence of UTP, Mn
2+
, and a poly(A) template. The first consists of an elongation reaction of an oligo(dT)
15
primer into poly(U). The second is a protein-priming reaction in which the enzyme covalently links UMP to the hydroxyl group of tyrosine in the terminal protein VPg, yielding VPgpU. This precursor is elongated first into VPgpUpU and then into VPg-linked poly(U), which is identical to the 5′ end of picornavirus minus strands. The two forms of the enzyme are about equally active both in the oligonucleotide elongation and in the VPg-primed reaction. Various synthetic mutant VPgs were tested as substrates in the VPg uridylylation reaction.
The Molecular and Crystal Structure of Buprenorphine Hydrochloride, a Morphine Analogue
Authors: Kratochvíl Bohumil , Hušák Michal , Bulej Petr , Jegorov Alexandr
Published: July 2002

The structure of buprenorphine hydrochloride {(6R,7R,14S)-17-cyclopropylmethyl-7,8-dihydro- 7-[(1S)-1-hydroxy-1,2,2-trimethylpropyl]- 6-O-methyl-6,14-ethano-17-normorphine hydrochloride} was solved by direct methods and refined anisotropically to the R value of 0.062 for 3 049 observed reflections. The substance crystallizes in the tetragonal space group P43212, a = b = 11.513(2) Å, c = 42.054(8) Å, V = 5 574(2) Å3, Z = 8, Dcalc = 1.201 g cm-3, μ(MoKα) = 0.17 mm-1. The compound is the first morphine derivative with a 6,14-ethano bridge whose molecular structure has been solved.
X-Ray Structure Analysis and NMR Study of Sesquiterpene Lactone Hirsutolide
Authors: Rychłewska Urszula , Buděšínský Miloš , Grabarczyk Halina , Drożdż Bohdan , Holub Miroslav
Published: July 2002

Hirsutolide, the C(8)-lactonized sesquiterpene of the heliangolide type has been studied by X-ray and NMR methods. In crystal the ten-membered ring conformation closely resembles the conformation observed in C(6)-lactonized heliangolides. This conformation, which can be described as a boat-chair is contrasted with the chair-chair conformation found in the crystals of other C(8)-lactonized heliangolide, scorpioidine. Broad signals in 1H and 13C NMR spectra indicated the conformation equilibrium in solution which was confirmed by observation of signals of two conformers (ca 3 : 1) in low temperature 1H NMR spectra. The major conformer is the one present in the crystal structure of hirsutolide and the minor conformer corresponds very likely to the one observed in the crystal structure of scorpioidine.
Spectrophotometric Study of the Formation of Iron(III) Complexes with Some Salicylic Acid Derivatives
Authors: Surányi Terézia M. , Djurendić Evgenija A. , Vastag Gyöngyi Gy.
Published: July 2002

The stoichiometric ratio and stability constants of iron(III) complexes with 1,n-di-O-salicyloylalkane-1,n-diols (n = 2 - 8) and N,N'-disalicyloyl-1,n-alkanediamines (n= 2 - 4) were determined spectrophotometrically. In 61.10% aqueous ethanol, the iron-to-ligand ratio is 1 : 1 (FeL+). The stability constants of the complexes were measured at 298 K and μ = 0.5 mol dm-3 (LiCl). Since the determination was performed in a glycinate buffer, the constants were corrected for the side reaction of iron(III) with glycine.
Suspension of Solid Particles
Authors: Rieger František , Sinevič Václav
Published: July 2002

The results of agitator speed measurements for complete suspension of solid particles reported earlier were completed by new measurements in larger vessel and with smaller particles and with particles of different density. Good agreement between earlier and new results justifies the applicability of the correlation proposed for calculation of critical agitator speed.
Polarographic Reduction and Potential Carcinogenity of Substituted 1,3,5-Triazine Nucleosides
Authors: Novotný Ladislav , Vachálková Anna , Pískala Alois
Published: July 2002

The DC polarographic reduction of 11 new 5-azacytidine (5-azaCyd) and 5-azauridine (5-azaUrd) derivatives in strictly anhydrous dimethylformamide (DMF) was investigated. The reduction occurred within one two-electron step for all of the substances except 6-amino-3-(β-D-ribofuranosyl)-1,3,5-triazine-2,4(1H,3H)-dione, which was reduced in two one-electron steps. The 5-azaCyd monomethyl derivatives (6-methyl-5-azaCyd and N4-methyl-5-azaCyd) gave polarographic maxima of the 1st kind. Substitution in position 6 poses a marked hindrance to the reducibility of the nucleoside analogues. The α-lipoic acid test was applied to all the compounds to obtain the potential carcinogenity index (tg α). The highest tg α value, viz. 0.372, was found for 6-methyl-5-azaCyd; this value even exceeds that of 5-azaCyd (0.295), a compound which has been included in the category of substances probably carcinogenic to humans in the WHO classification. For the majority of the remaining compounds, the tg a values do not suggest any significant carcinogenic activity.
Investigation of the Polarographic Properties and Potential Carcinogenity of Some Hydroxyurea Derivatives by DC Polarography
Authors: Novotný Ladislav , Vachálková Anna , Pískala Alois
Published: July 2002

Polarographic reduction was studied for a series of 7 urea derivatives and the results were used to assess their potential carcinogenity. The polarographic reduction was examined in absolutely anhydrous dimethylformamide by DC polarography. In the conditions applied, the majority of the compounds was reduced within a single two-electron step, only biuret and its formyl derivative were reduced in two one-electron steps. The potential carcinogenity of the substances was assessed based on the tg α value of the slope of dependence of the polarographic wave height on the concentration of α-lipoic acid added as a test substance. For hydroxyurea, which is the only substance in this series for which a carcinogenic activity has been demonstrated, the tg α parameter attained a value of 0.290. Still higher values were obtained for the formyl derivatives - formylbiuret (0.362) and 2-carbamoyl-1-formylguanidine (0.510). So high tg α values warn of a significant potential carcinogenity. The other substances studied exhibited considerably lower tg α values, indicating that their potential carcinogenity will be low.
Reaction of Bis(trimethylphosphine)heptahydrotetraboron(1+) Cation with Trimethylphosphine
Authors: Kameda Mitsuaki , Kodama Goji
Published: July 2002

The reaction of the arachno-bis(trimethylphosphine)heptahydrotetraboron(1+) cation, B4H7 . 2 P(CH3)3+ (1), with trimethylphosphine paralleled with that of the isoelectronic arachno-trimethylphosphine-tetraborane(8), B4H8 . P(CH3)3 (2). Thus, it first gave the hypho-tris(trimethylphosphine)heptahydrotetraboron(1+) cation, B4H7 . 3 P(CH3)3+ (3), which further reacted with P(CH3)3 to finally give cleaved products, the hypho-tetrakis(trimethylphosphine)tetrahydrotriboron(1+) cation, B3H4 . 4 P(CH3)3+ (4), and trimethylphosphine-borane(3), BH3 . P(CH3)3. The effect of the ionic charges upon the reaction rates was apparent. Thus, the second reaction for 1 was rapid at room temperature while the corresponding reaction for 2 was slow and the negatively charged isoelectronic species, the B4H9 . P(CH3)3+ anion, did not undergo the second reaction. The above two hypho polyboron complex cations, 3 and 4, were characterized by 11B and 31P NMR spectroscopy. Like its isoelectronic counterparts, the cation 3 was highly fluxional; at room temperature the three B-P(CH3)3 groups were equivalent on the NMR time scale.
Evaluation of Molecular Integrals in a Mixed Gaussian and Plane-Wave Basis by Means of the Faddeeva Function and Its Derivatives
Authors: Čársky Petr , Reschel Tomáš
Published: July 2002

We present formulas for two-electron free-free exchange integrals and integrals with three Gaussians and one plane-wave function that are required in calculations of electron scattering by polyatomic molecules. The formulas of integrals with p- and d-type Gaussians were obtained by differentiation of the fundamental integrals (sk'|sk) and (ss|sk) that contain s-type Gaussians only and that may be evaluated by means of the Faddeeva function w. Explicit formulas are given for the two types of integrals in the spd Gaussian basis.
Trigold(I) Phosphine Derivatives of Clusters Containing Octahedral Rh2Ru4B-Boride Cores: The X-Ray Structure of [Rh2Ru4(CO)15Rh2Ru4B{AuPCy3}3] (Cy = cyclohexyl)
Authors: Hattersley Andrew D. , Housecroft Catherine E. , Rheingold Arnold L.
Published: July 2002

The reaction of [Rh(CO)2Cl]2 with [HRu4(CO)12BH]- followed by treatment with an excess (at least three-fold) of [Cy3PAuCl] (Cy = cyclohexyl) leads to the formation of [Rh2Ru4(CO)16B{AuPCy3}] (previously prepared by another route) and [Rh2Ru4(CO)15B{AuPCy3}3]. The new trigold derivative has been characterized by spectroscopic and mass spectrometric methods, and by single crystal X-ray diffraction. It possesses an octahedral Rh2Ru4 core containing an interstitial boron atom; two of the gold(I) phosphine units cap two adjacent faces and the third bridges an edge of the octahedral cage. There are no close Au···Au contacts. Reactions of [Rh2Ru4(CO)16B]- with [(R3PAu)3O]+ (R = Ph, 2-MeC6H4) resulted in the formation of [Rh2Ru4(CO)15B{AuPR3}3]; for R = Ph, two isomers in respect of the arrangements of the AuPPh3 were isolated. Fluxional processes involving the gold(I) phosphine fragments have been observed using solution variable-temperature 31P NMR spectroscopy.
Effect of Alcohols on Polarographic Reduction of Oximes
Authors: Aleksić Mara , Kapetanović Vera , Zuman Petr
Published: July 2002

Limiting currents of the protonated form of oximes decrease with increasing concentration of alcohols in alcohol-water mixtures. The measured current limits to a value corresponding to a two-electron reduction. The decrease is attributed to additions of the alcohol to the imine formed as intermediate. At a given concentration of the alcohol the drop of current increases in the sequence MeOH < EtOH < i-PrOH < tert-BuOH, following the increasing nucleophilicity of the alcohol.
Extraction of Tungsten with Trialkylamine - Effect of pH
Authors: Procházka Jaroslav , Heyberger Aleš , Horáček Jan , Volaufová Eva , Voborská Jitka , Macháčková Eva
Published: July 2002

Extraction equilibrium in the system aqueous solution of sodium tungstate-solution of trialkylamine in a mixed diluent was investigated. A tertiary amine with C7-C9 straight alkyl chains was dissolved in a mixture of tributyl phosphate and kerosene and presaturated with sulfuric acid to give normal trialkylamine sulfate. Extraction isotherms at 25 °C and at several constant values of equilibrium pH were measured in a broad range of aqueous tungstate concentrations. pH 2.0-6.0 was adjusted by addition of sulfuric acid during equilibration. The equilibrium tungstate and sulfate contents in both phases were determined. A typical tungstate isotherm exhibits a steep ascending part in the low concentration range, corresponding to the region of anion exchange, and a flat part in the high concentration range, where the acid content in the organic phase is virtually exhausted. The level of the flat part decreases with growing pH, corresponding to the increasing number of negative charges per tungsten atom in the tungstate polyanions extracted. At pH > 5, also the effect of hydrolysis of amine sulfate could be detected.
Advances in gastroenterology and hepatology
Authors: Bateson M C
Published: July 2002

This is a review of some of the most important growing points in the specialties of gastroenterology and hepatology. It does not aim to be completely comprehensive but to pick out major areas of importance to examination candidates and doctors without special experience in the field.

Topics covered include: upper gastrointestinal haemorrhage; Barrett's oesophagus; carcinoma of the oesophagus; achalasia;Helicobacter pylori; duodenal ulcer prevention; coeliac disease; dermatitis herpetiformis; Crohn's disease; small bowel overgrowth; ulcerative colitis; carcinoma of the large bowel; obesity; endoscope sterilisation; gall stones; liver transplantation; autoimmune liver disease; viral hepatitis; metabolic liver diseases; and pancreatic insufficiency.
Arrhythmogenic right ventricular dysplasia. An illustrated review highlighting developments in the diagnosis and management of this potentially fatal condition
Authors: Fisher N G , Gilbert T J
Published: July 2002

Arrhythmogenic right ventricular dysplasia is an inherited, progressive condition. Characterised by fatty infiltration of the right ventricle, it frequently results in life threatening cardiac arrhythmias, and is one of the important causes of sudden cardiac death in the young. There are characteristic electrocardiographic and echocardiographic features that all physicians need to be aware of if we are to reduce these occurrences of premature death. Diagnosis with magnetic resonance imaging is discussed along with current treatment options.
Neuralgic amyotrophy as a presenting feature of infective endocarditis
Authors: English P , Maciver D
Published: July 2002

A 35 year old man presented to his general practitioner with severe right shoulder pain and subsequent weakness and wasting of the muscles in the affected shoulder girdle three weeks after a dental filling. His symptoms persisted despite standard treatment. He developed malaise, night sweats, weight loss, a petechial rash and a microcytic anaemia. On admission to hospital three months after the start of his symptoms he had also developed splenomegaly and the murmur of aortic regurgitation. Investigations confirmed the diagnoses of infective endocarditis and neuralgic amyotrophy. In this case neuralgic amyotrophy appears to have been the presenting feature of infective endocarditis. This association has not previously been described.
Ethical, professional, and legal obligations in clinical practice: a series of discussion topics for postgraduate medical education
Authors: Gore D M
Published: July 2002

This is the second discussion topic in a series of five dealing with ethical, professional, and legal obligations of clinical practice. Junior doctors tend to lack confidence in these subjects, and thus I organised a series of informal discussions in our surgical unit on which these articles are based. The sessions were prepared with reference to non-academic literature readily available from the General Medical Council (GMC) and the medical defence organisations. While our unit dealt with these issues from a surgical perspective, the obligations of clinical practice apply to all practitioners and the series could be easily modified for other clinical specialties.
A 25 year old woman presenting with bleeding disorder and nystagmus
Authors: Saif M W , Hamilton J M
Published: July 2002

A 25 year old white woman presented with a history of severe bleeding after tooth extraction for a wisdom tooth. She admitted to a long history of nose bleeds; these had occurred about once every three weeks for many years and had required blood transfusion twice. She had an appendicectomy done at the age of 11 complicated by severe bleeding that required blood transfusion. The patient said that since childhood she had easily bruised and had severe bleeding after minor cuts. She started her menarche at the age of 14 and since then had menorrhagia. She denied experiencing haematemesis, haematochezia, joint pains, shortness of breath, abdominal pain, or any other systemic complaints.
Adenocarcinoma of the lung in Chinese patients: a revisit and some perspectives from the literature
Authors: Lam B , Lam W K , Lam C L , Ooi G C , Ho J C M , Wong M P , Tsang K W
Published: July 2002

Aim

To establish an updated clinical profile of adenocarcinoma of the lung.

Design

Retrospective review of clinical charts, chest radiography, and computed tomography of consecutive patients who attended Queen Mary Hospital in Hong Kong between June 1995 and December 1997.

Results

In the 115 patients studied, 13% were <40 years of age (33.3% ever smokers). Haemoptysis is more common among patients with early disease, while finger clubbing was detected more commonly among smokers and ex-smokers. Most (98.3%) patients had abnormal chest radiology including presence of mass lesion, pleural effusion, collapse/consolidation, and effusion. Patients with adenocarcinoma were significantly more likely to be younger, female, in advanced disease (stage IIIB and IV), non-smoker, and symptomatic on presentation (p<0.05) than those with squamous cell lung cancer (n=128).

Conclusion

The clinical profile of Chinese adenocarcinoma patients should help clinicians in the diagnosis and management of these patients.
Liver transplantation for chronic liver disease: advances and controversies in an era of organ shortages
Authors: Prince M I , Hudson M
Published: July 2002

Since liver transplantation was first performed in 1968 by Starzl et al, advances in case selection, liver surgery, anaesthetics, and immunotherapy have significantly increased the indications for and success of this operation. Liver transplantation is now a standard therapy for many end stage liver disorders as well as acute liver failure. However, while demand for cadaveric organ grafts has increased, in recent years the supply of organs has fallen. This review addresses current controversies resulting from this mismatch. In particular, methods for increasing graft availability and difficulties arising from transplantation in the context of alcohol related cirrhosis, primary liver tumours, and hepatitis C are reviewed. Together these three indications accounted for 42% of liver transplants performed for chronic liver disease in the UK in 2000. Ethical frameworks for making decisions on patients’ suitability for liver transplantation have been developed in both the USA and the UK and these are also reviewed.
A NON-DEFINABILITY RESULT FOR A PREDICATIONAL LANGUAGE WITH THE USUAL CONTROL
Authors: ELBL BIRGIT
Published: July 2002

A term calculus corresponding to pure prolog is introduced and extended by an if-then-else construct to obtain the expressiveness of pure prolog + cut. In contrast to functional terms which have a single value the evaluation of predicational terms leads to an enumeration of the several (finite or infinite) solutions. A user can control up to which point this stream of answers is computed and restrict his attention to a special position in this stream. We show that this can not be achieved inside the program. The addition of if-then-else offers the possibility to pick the first answer but this does not carry over to the second or later position. This is proved used the denotational semantics of the predicational language.
DIFFERENTIAL CALCULUS ON A THREE-PARAMETER OSCILLATOR ALGEBRA
Authors: IRAC-ASTAUD MICHÈLE
Published: July 2002

Two differential calculi are developed on an algebra generalizing the usual q-oscillator algebra and involving three generators and three parameters. They are shown to be invariant under the same quantum group that is extended to a ten-generator Hopf algebra. We discuss the special case where it reduces to a deformation of the invariance group of the Weyl-Heisenberg algebra for which we prove the existence of a constraint between the values of the parameters.
THE CONTINUOUS SPIN RANDOM FIELD MODEL: FERROMAGNETIC ORDERING IN d≥3
Authors: KÜLSKE CHRISTOF
Published: July 2002

We investigate the Gibbs-measures of ferromagnetically coupled continuous spins in double-well potentials subjected to a random field (our specific example being the ϕ4 theory), showing ferromagnetic ordering in d≥3 dimensions for weak disorder and large energy barriers. We map the random continuous spin distributions to distributions for an Ising-spin system by means of a single-site coarse-graining method described by local transition kernels. We derive a contour-representation for them with notably positive contour activities and prove their Gibbsianness. This representation is shown to allow for application of the discrete-spin renormalization group developed by Bricmont/Kupiainen implying the result in d≥3.
A NONDISPERSIVE AND NONDISSIPATIVE FINITE-DIFFERENCE LATTICE BOLTZMANN METHOD
Authors: HÁZI GÁBOR
Published: July 2002

In this paper a finite-difference lattice Boltzmann method is introduced, discretizing the lattice Boltzmann equation by centered-time and centered-space finite differences. It is well known from numerical analysis that such discretization of the derivatives results in numerical dispersion and dissipation. The numerical dispersion is eliminated perfectly by using a fictitious absorption term in the master equation and the dissipation is compensated by solving a second, reference equation and the method of division. As a test problem, the evolution of a decaying Taylor vortex in a 2π periodic domain is studied.
NONRELATIVISTIC SPIN-½ PARTICLE IN AN ARBITRARY NON-ABELIAN MAGNETIC FIELD IN TWO SPATIAL DIMENSIONS
Authors: CLARK T. E. , LOVE S. T. , NOWLING S. R.
Published: July 2002

The (group and spin space) matrix Hamiltonian describing the dynamics of a non-relativistic spin-½ particle moving in a static, but spatially dependent, non-Abelian magnetic field in two spatial dimensions is shown to take the form of an anticommutator of a nilpotent operator and its Hermitian conjugate. Consequently, the (group space) matrix Hamiltonians for the two different spin projections form partners of a supersymmetric quantum mechanical system. The resulting supersymmetry algebra is exploited to explicitly construct the exact zero energy ground state wave function(s) for the system. The remaining eigenstates and eigenvalues of the two partner Hamiltonians form positive energy degenerate pairs.
THE SENSITIVITY OF ANTENNAS FOR GRAVITATIONAL WAVE DETECTION
Authors: BRAUTTI GIULIO , PICCA DOMENICO
Published: July 2002

This work shows that the quantum calculation of the energy exchanged between gravitational waves and resonating antennas contains a term linear in the Riemann tensor if the oscillator is supposed to be in a coherent state, while it contains only quadratic terms if it is in a stationary state. In some cases the latter hypothesis, presently accepted in the literature, underestimates the sensitivity of GW antennas by several orders of magnitude. The authors show the need for the correction of the error, while its origin and consequences are explained.
PHASE SEPARATION AND STRIPES IN Ln2MO4+δ
Authors: POIROT-REVEAU NATHALIE , GERVAIS FRANÇOIS
Published: July 2002

A single crystal of La 2 NiO 4+δ with δ=0.11 giving a hole concentration favouring phase separation, has been studied by infrared reflectivity between 4 K and 300 K, from 20 to 7,000 cm -1. The spectra cannot be fitted properly by usual models and both plasma frequency and integrated conductivity shows two anomalies with temperature interpretable in terms of charge and spin ordering and their arrangements into stripes.
Fermi surface and photoemission lineshape of incommensurate CDW systems
Authors: Seibold G. , Castellani C. , Di Castro C. , Grilli M.
Published: July 2002

We study the single-particle spectra of a model which shows an incommensurate charge-density wave (CDW) instability arising from the competition between phase separation and long-range Coulomb interactions. Starting from an open Fermi surface we find that the resulting CDW is oriented along the (1,0)- and (or) (0,1)-direction which (besides a purely one-dimensional structure) allows for a two-dimensional "eggbox type" charge modulation. This leads to a substantial enhancement of the van Hove singularities and the spectral weight of Fermi surface states near the M-points tends to be suppressed. Remarkably, a leading edge gap arises near these points, which, in the eggbox case, leaves finite arcs of the Fermi surface gapless. Extending this approach to the inclusion of dynamic incommensurate CDW fluctuations in the superconducting state we calculate the photoemission lineshape which agrees well with experimental data of underdoped Bi2212 compounds.
MACROSCOPICALLY QUANTIZED HOLE STATES IN La2-χSrχCuO4-δ FILM CRYSTAL OBSERVABLE UP TO ROOM TEMPERATURE
Authors: SUGAHARA M. , OGI S. , ARAKI K. , SUGIURA R.
Published: July 2002

Theoretical study of multi-layered CuO 2 surfaces with localization potential shows that (i) special stable macroscopic quantum states appear when [Formula: see text], where χ is the doping level and G is the unit-cell number, and that (ii) the physical phenomena related to ‖c charge motion takes place just as expected in the fictitious situation where whole uniformly doped holes concentrate in one-side surface. In the dielectric measurement of doping-level dependence and film-thickness dependence on c-oriented La 2-χ Sr χ CuO 4-δ film, we find that (a) anomalous low-frequency polarization is enhanced when a scaling parameter χG is near to [Formula: see text], that (b) quasi-static measurement of the polarization property in low doped film shows two typical characteristics explicable by the fictitious charge concentrations, and that (c) ‖c small-voltage conduction measurement on low doped film also shows two types of characteristic which are switched each other triggered by laser irradiation. Since these macroscopic quantum effects with plural levels with very long life time are observable even up to room temperatures, they may be useful in quantum computing application.
PAIRING IN INHOMOGENEOUS SUPERCONDUCTORS
Authors: EROLES J. , ORTIZ G. , BALATSKY A. V. , BISHOP A. R.
Published: July 2002

Starting from a t-J model, we introduce inhomogenoeus terms to mimic stripes. We find that if the inhomogeneous terms break the SU(2) spin symmetry the binding between holes is tremendously enhanced in the thermodynamic limit. In any other model (including homogeneous models) the binind in the thermodynamic limit is small or neglible. By including these inhomogeneous terms we can reproduce experimental neutron scattering data. We also discuss the connection of the resulting inhomogeneity-induced superconductivity to recent experimental evidence for a linear relation between magnetic incommensurability and the superconducting transition temperature, as a function of doping.
INVESTIGATION ON NITROGENATED DLC FILMS FOR ANTI-REFLECTION COATING APPLICATION
Authors: VINOD P. R. , KAKIUCHI H. , TERAI T. , ITAKURA A. N. , KITAJIMA M.
Published: July 2002

Diamond-like carbon (DLC) films were deposited with a RF magnetron sputtering device. The target used was high purity graphite (99.999%) and n-type Si was used as the substrate. In order to get good anti-reflective films nitrogen gas was used to a small extent in addition to hydrogen gas thus resulting in a-C:H:N thin films. From the Ellipsometry studies it was found that the deposited films were good for optical coating. XPS studies indicate that film contains carbon in graphitic form, DLC form and CN bonding in sp 2 trigonal and sp 3 tetrahedral structure. FT-IR spectra analysis agrees with the results of XPS data. AFM studies show that the surface roughness of the films depend on the film composition.
STRUCTURAL COMPLIANCE, MISFIT STRAIN AND STRIPE NANOSTRUCTURES IN CUPRATE SUPERCONDUCTORS: IMPLICATIONS AND EXPERIMENTAL OBSERVATIONS
Authors: BILLINGE S. J. L. , DUXBURY P. M.
Published: July 2002

Structural compliance is defined as the ability of a crystal structure to accommodate variations in local atomic bond-lengths without incurring large strain energies. The structural compliance of cuprates is relatively small. In the presence of charge stripes short, highly doped, Cu-O-Cu bonds become subject to a tensile misfit strain. We show that this leads to nanoscale microstructures. This explains a number of experimental observations as we discuss here.
Symmetry of the Pairing State and Transition Temperature in the P-D Model
Authors: Citro R. , Marinaro M.
Published: July 2002

The effective pairing interaction and the superconducting transition temperature Tc, mediated by both spin and charge fluctuations, are investigated on the basis of the simplest p - d model by considering a Bethe-Salpeter equation for the vertex functions within a generalized cumulant expansion. The comparison with experimental results of hole-doped cuprates is discussed.
Numerical Study of the Role of Magnetic Field Ramping Rate on the Structure Formation in Magnetorheological Fluids
Authors: Mohebi M. , Jamasbi N. , Flores G. A. , Liu Jing
Published: July 2002

A molecular dynamics model is presented to understand the structural formation of MR fluids by including the thermal motion of the particles. The simulation results indicate that the complexity of the lateral pattern as viewed in the direction of the applied field increases with the rate of the application of external magnetic field. We have also found that the maximum range for attractive interaction (escape distance) for two initially straight chains increases with temperature. These results are relevant to understand the mechanisms and conditions for the formation of labyrinthine and columnar patterns found in MR fluids.
MECHANISM OF ELECTRON CAPTURE BY AN INTENSE LASER BEAM
Authors: YUAN X. Q. , HO Y. K. , WANG P. X. , KONG Q. , CAO N.
Published: July 2002

In this letter we report the studies of the mechanism which can lead to substantial energy exchange between electrons and intense laser beams interacting in vacuum. It has been found that the wave phase experienced by the electron when it encounters the intense beam is a crucial ingredient for discriminating the two totally different trajectories: capture and violent acceleration scenario (CAS) or conventional inelastic scattering (IS). When an electron is captured, due to the diffraction effect of the optical beam near the focused region, the effective wave-phase velocity along the dynamic trajectory of the captured particle is found to be less than c, the speed of light in vacuum. Thus the captured electron can remain in the acceleration phase of the wave for a long time, and gain considerable energy from the laser field.
CHARACTERIZATION OF SUPERCONDUCTING MULTILAYERED FILMS USING RBS AND TEM
Authors: ENGEL ANDREAS , JOE TRODAHL H. , MARKWITZ ANDREAS , JOHN KENNEDY V.
Published: July 2002

Amorphous multilayered films of superconducting Ta x Ge 1-x -alloy and insulating Ge have been characterized using RBS and TEM. The films were prepared using physical vapor evaporation and the substrates were tilted with respect to the incoming vapor flux, in order to achieve a columnar microstructure exhibiting strong flux-pinning in the superconducting mixed phase. RBS and TEM were successfully applied to obtain detailed information on the layering, columnar microstructure and chemical composition of the superconducting films.
THE INFLUENCE OF HEAT TRANSFER ON PHYSICAL AND MECHANICAL PROPERTIES IN NONCONVENTIONAL PROCESSES OF METALLIC SOLIDS PLASTIC DEFORMATION
Authors: POP MARIANA , CANTA TRAIAN , POP AUREL
Published: July 2002

The aim of this paper is to present a mathematical model for the steady state of the dieless drawing process. With this model, it is possible to study the influence of various process parameters, such as temperature, strain, strain rate and stress. The paper also presents some elements of the process control for producing variable cross-sections (cone-contour and sinus-contour).
MULTI-ANYONS IN THE MAGNETIC FIELD
Authors: CHOI TAESEUNG , LEE JUNGJAI , RYU CHANG-MO
Published: July 2002

We consider the external magnetic field effects on the two types of anyons with fractional statistical parameter p/q with coprimes p and q, one with a fractional charge e/q and the other with a fractional flux p ϕ0/q by exact ground state wave function. We also study the geometry in which a two-dimensional strip of anyons contains an island of anyons with different statistical parameters in their equilibrium. The equilibrium inside an island is shown to be periodic with respect to the magnetic flux through the island. The period for the fractional charge anyon equals to the integer multiple of the fundamental flux quantum. On the other hand, in the case of the fractional flux anyon, the period is found to be the fractional multiple of the fundamental flux quantum.
DECODING OF SIGNAL FROM PHASE MODULATED UNSTABLE PERIODIC ORBIT
Authors: KULKARNI D. R. , AMRITKAR R. E.
Published: July 2002

In the method of secure communication suggested by Abarbanel and Linsay, a binary message is encoded by phase modulation of an unstable periodic orbit (UPO) of a chaotic system. It is demonstrated that the encoded message can be decoded from the transmitted signal alone without the knowledge of chaotic system, its orbit, and encoding scheme. The decoding method is based on the fact that errors in single step prediction for models which reconstruct the state space using the local linear approximation are relatively large for the points on UPO in the transmitted signal. This enables us to extract the UPO from the transmitted signal. The identification of UPO is then used to recover the original message.
EXACT STATE RECONSTRUCTORS IN THE RECOVERY OF MESSAGES ENCRYPTED BY THE STATES OF NONLINEAR DISCRETE-TIME CHAOTIC SYSTEMS
Authors: SIRA-RAMÍREZ HEBERTT , IBÁÑEZ CARLOS AGUILAR , SUÁREZ-CASTAÑÓN MIGUEL
Published: July 2002

In this article we propose the use of nonlinear exact chaotic system state reconstructors for the fast and efficient decoding of multiple discrete-time chaotic encrypted digital messages. Exact state reconstruction features a state estimation error which settles to zero in a finite number of steps. This makes the method specially suitable for chaotic encrypted transmission of digitized files over "noise-free" environments such as the Internet. The method was tested in an actual transmission involving the simultaneous decoding of digitized color images and text files.
CHUA'S ATOM
Authors: ROMANO DANIELA , BOVATI MIRKO , MELONI FRANCO
Published: July 2002

The response of a chaotic Chua's electronic circuit and that of an atom show interesting common features. Starting from the comparison of the qualitative behavior of bifurcation diagrams and electronic spectroscopic series of atoms we associate order–chaos transition with those of an electron passing from a quantized to a continous energy spectrum. The resulting atomic model suggests an analogy between the synchronization of two Chua's atoms and chemical covalent bonding.
MINIMUM NUMBER OF FIXED POINTS FOR MAPS OF THE FIGURE EIGHT SPACE
Authors: LLIBRE JAUME , NUNES ANA
Published: July 2002

Let E denote the figure eight space, and M(f) the minimum number of fixed points achievable among maps homotopic to a given self-map f of E. We give an algorithm to compute M(f) from the induced homomorphism f* on the fundamental group of E.
THE COMBINATION THEOREM AND QUASICONVEXITY
Authors: KAPOVICH ILYA
Published: July 2002

We show that if G is a fundamental group of a finite k-acylindrical graph of groups where every vertex group is word-hyperbolic and where every edge-monomorphism is a quasi-isometric embedding, then all the vertex groups are quasiconvex in G (the group G is word-hyperbolic by the Combination Theorem of M. Bestvina and M. Feighn). This allows one, in particular, to approximate the word metric on G by normal forms for this graph of groups.
HOPF ALGEBRAS AND INVARIANTS OF COMBED AND FRAMED 3–MANIFOLDS
Authors: BENVENUTI SILVIA
Published: July 2002

We describe an algorithm to compute the Kuperberg invariant of a combed or framed 3–manifold, starting from a presentation of such a manifold in terms of branched standard spines.
GENERAL RELATIVISTIC RELATION BETWEEN DENSITY CONTRAST AND PECULIAR VELOCITY
Authors: MANSOURI REZA , RAHVAR SOHRAB
Published: July 2002

Concepts like peculiar velocity, gravitational force, and power spectrum and their interrelationships are of utmost importance in the theories of structure formation. The observational implementation of these concepts is usually based on the Newtonian hydrodynamic equations, but used up to scales where general relativistic effects come in. Using a perturbation of FRW metric in harmonic gauge, we show that the relativistic effects reduce to light cone effects including the expansion of the universe.

Within the Newtonian gravitation, the linear perturbation theory of large scale structure formation predicts the peculiar velocity field to be directly proportional to gravitational force due to the matter distribution. The corresponding relation between peculiar velocity field and density contrast has been given by Peebles. Using the general relativistic perturbation we have developed, this familiar relation is modified by doing the calculation on the light cone in contrast to the usual procedure of taking a spacelike slice defined at a definite time. The velocity and density-spectrum are compared to the familiar Newtonian expressions. In particular, the relativistic β-value obtained is reduced and leads to an increased bias factor or a decreased expected amount of the dark matter in a cluster.
FIND THE MANDELBROT-LIKE SETS IN ANY MAPPING
Authors: LIAW SY-SANG
Published: July 2002

The Mandelbrot-like sets appear in the parameter spaces of many one-parameter complex mappings. We find that the type of these sets depends on the multiplicity of the critical points of the mappings. We give the effective map for parameters in these sets, and accordingly calculate the positions, the sizes, and the orientations of these Mandelbrot-like sets for any one-parameter complex mappings.
SURGICAL TREATMENT OF SEVERE FRACTURE DISLOCATIONS OF THE PROXIMAL INTERPHALANGEAL JOINT
Authors: Büchler Ueli
Published: July 2002

A method is presented for open reduction, bone grafting, minimal internal fixation and ancillary dynamic external fixation of unstable impacted fracture-dislocations of the proximal interphalangeal joint of the finger involving more than 40% of the surface of the joint plateau.
CONGENITAL MALFORMATIONS OF THE HAND: NON-CLASSIFIABLE CASES
Authors: Buck-Gramcko Dieter , Ogino Toshihiko
Published: July 2002

Twelve patients with unclassifiable congenital anomalies of the upper extremity were described. They showed a combination of several different forms of malformation.
Double Crush Syndrome Related to the Thoracic Outlet Syndrome
Authors: Nishida Jun , Ichinohe Katsuaki , Shimamura Tadashi , Abe Masataka
Published: July 2002

Cases diagnosed as having thoracic outlet syndrome were examined by neurological examination, including provocation tests, electromyography and radiological examinations, to detect other sites of entrapment neuropathy of the upper extremity. During the last four years, 555 upper extremities of 494 patients were diagnosed as having thoracic outlet syndrome. Forty-five patients (9.3%) were diagnosed as having other entrapment neuropathy in one extremity. Ten cases were complicated by cervical radiculopathy, 15 by carpal tunnel syndrome, 11 by cubital tunnel syndrome, five by radial tunnel syndrome, two by ulnar tunnel syndrome, two by both carpal tunnel and cubital tunnel syndrome, and one by both cubital and ulnar tunnel syndrome.

Surgery was performed for 15 limbs, and the distal lesion was operated on the first in two-thirds of these patients. The relationship between thoracic outlet syndrome and cubital tunnel syndrome or carpal tunnel syndrome has been reported by several authors, but the rates of incidence vary among reports. The rate of incidence seems to depend upon the diagnostic technique. After adoption of the appropriate provocation tests, patients with thoracic outlet syndrome complicated by other entrapment neuropathies were detected at a relatively high rate of incidence. Provocation tests seem to be an essential measure for the diagnosis of double crush syndromes.