bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of jump training on passive mechanical stress and stiffness in rabbit skeletal muscle: role of collagen
Authors: Ducomps C. , Mauriège P. , Darche B. , Combes S. , Lebas F. , Doutreloux J. P.
Published: June 2003

Aims:  This study evaluated the effect of a 15‐week jump training period on mechanical parameters and collagen concentration of different muscle types in rabbits, at 50, 90 and 140 days of age.

Methods:  Trained (T) animals were made to jump over obstacles in order to get food and water. The height of the obstacle was increased according to the animal's age. Control (C) animals were sedentary. Mechanical parameters (force, stress, stiffness) and collagen concentration were measured in Extensor Digitorum Longus (EDL), Rectus Femoris (RF), Semimembranosus Proprius (SMP) and Psoas Major (PSOAS).

Results:  Both EDL and RF collagen concentrations and passive mechanical parameters increased between 50 and 140 days of age (P < 0.001), whereas SMP and PSOAS collagen concentrations decreased (P < 0.001). Soluble collagen concentration decreased similarly with age in all muscles and groups. Exercise training at 140 days induced a significant increase in force (EDL 20.4% and RF 15.3%, 0.01 < P < 0.05), stress (EDL 26.8% and RF 22.6%, P < 0.001), and stiffness (EDL 13.2% and RF 16%, 0.001 < P < 0.05) with a greater collagen concentration (EDL 16.1% and RF 19.1%, 0.001 < P < 0.05). Finally, stiffness and stress are well correlated with collagen concentration in EDL and RF muscles at 140 days (0.74 < r < 0.84, P < 0.05).

Conclusion:  These results suggest that jump training can increase muscle capabilities of strength and stiffness in fast‐twitch mixed muscles with pennate architecture (EDL, RF). This increase is essentially mediated by a rise in cross‐linked collagen fraction, coupled with a relative decrease in soluble collagen. The collagen covalent cross‐links improve resistance and stability in force transmission processes during stretching.
Endogenous NO does not regulate baseline pulmonary pressure, but reduces acute pulmonary hypertension in dogs
Authors: Sander M. , Welling K. ‐L. K. , Ravn J. B. , Boberg B. , Amtorp O.
Published: June 2003

It has remained unclear whether endogenous production of nitric oxide (NO) plays an important role in the regulation of physiologically normal pulmonary pressures. Severe alveolar hypoxia is accompanied by decreased pulmonary NO production, which could contribute to the development of hypoxic pulmonary hypertension. On the other hand, pharmacological NO inhibition further augments this hypertensive response.

Aims:  The aims of the present study were to test: (a) whether NO contributes importantly in the maintenance of baseline pulmonary pressure; and (b) to which degree NO is involved in the pulmonary haemodynamic adjustments to alveolar hypoxia.

Methods:  In anaesthetized dogs (n = 37), the systemic and pulmonary haemodynamic effects of the NO synthase inhibitor, Nω‐nitro‐l‐arginine methyl ester (l‐NAME, 20 mg kg−1) and substrate, l‐arginine (200–500 mg kg−1), were determined at baseline and during alveolar hypoxia. Constant blood flows were accomplished by biventricular bypass, and systemic normoxaemia was maintained by extracorporeal oxygenation.

Results:  The primary findings were: (a) l‐NAME failed to increase baseline mean pulmonary arterial pressure (10.1 ± 0.7 vs. 10.5 ± 0.5 mmHg, P = ns), despite effective NO synthase inhibition as evidenced by robust increases in systemic arterial pressures; (b) l‐NAME augmented the pulmonary hypertensive response to alveolar hypoxia (10.2 ± 0.7 to 19.5 ± 1.7 with l‐NAME vs. 9.9 ± 1.1 to 15.5 ± 1.0 mmHg without l‐NAME, P < 0.05); and (c) l‐arginine failed to decrease baseline or elevated pulmonary pressures. Instead, prolonged l‐arginine caused increases in pulmonary pressure.

Conclusion:  These findings suggest that NO plays no significant role in the tonic physiological control of pulmonary pressure, but endogenous NO becomes an important vasodilatory modulator during elevated pulmonary pressure.
Is antimicrobial susceptibility testing necessary before second‐line treatment for Helicobacter pylori infection?
Authors: Miwa H. , Nagahara A. , Kurosawa A. , Ohkusa T. , Ohkura R. , Hojo M. , Enomoto N. , Sato N.
Published: June 2003

Background:  An antimicrobial susceptibility test for Helicobacter pylori before second‐line treatment is often performed, although whether the test is truly necessary remains unknown.

Patients and methods:  Eighty‐two patients with H. pylori infection for whom first‐line treatment with a 1‐week proton pump inhibitor/amoxicillin–clarithromycin (AC) regimen had failed were randomly assigned to two groups: those having or not having the susceptibility test before re‐treatment. The cure rates for these two groups were compared.

Results:  Five of the 82 patients were excluded from the analysis. For 38 patients in the susceptibility‐test group, we used what we considered the best regimen based on susceptibility testing: 10 patients [no resistance to clarithromycin (CAM)] received the lansoprazole–amoxicillin–clarithromycin regimen, 22 patients [19 CAM resistant, metronidazole (MNZ) susceptible; three failure of culture] were given the lansoprazole‐amoxicillin‐metronidazole (LAM) regimen, and six patients (both MNZ and CAM resistant) received dual therapy with omeprazole (OPZ) and amoxicillin (AMOX) in which the OPZ dose was determined by the CYP2C19 gene polymorphism. For 39 patients in the group with no susceptibility testing, LAM regimens were prescribed. The intention‐to‐treat (ITT)‐based cure rates in the groups with and without susceptibility testing were 81.6% (95% confidence interval; 66–92%) and 92.4% (79–98%), respectively, and there was no significant difference between these two groups.

Conclusion:  Susceptibility testing is not necessarily required before second‐line therapy if the first‐line treatment has been performed using proton pump inhibitor/AC regimens.
Mobilized peripheral blood SSCloALDHbr cells have the phenotypic and functional properties of primitive haematopoietic cells and their number correlates with engraftment following autologous transplantation
Authors: Fallon Paul , Gentry Tracy , Balber Andrew E. , Boulware David , Janssen William E. , Smilee Renee , Storms Robert W. , Smith Clay
Published: June 2003

Summary. We have developed an approach for identifying primitive mobilized peripheral blood cells (PBSC) that express high levels of aldehyde dehydrogenase (ALDH). PBSC were stained with a fluorescent ALDH substrate, termed BODIPY™‐aminoacetaldehyde (BAAA), and then analysed using flow cytometry. A population of cells with a low side scatter (SSC) and a high level of BAAA staining, termed the SSCloALDHbr population, was readily discriminated and comprised a mean of 3 ± 5% of leukapheresis samples. A mean of 73 ± 11% of the SSCloALDHbr population expressed CD34 and 56 ± 25% of all the mobilized CD34+ cells resided within the SSCloALDHbr population. The SSCloALDHbr population was largely depleted of cells with mature phenotypes and enriched for cells with immature phenotypes. Sorted SSCloALDHbr and SSCloALDHbr CD34+ PBSC were enriched for progenitors with the ability to (1) generate colony‐forming units (CFU) and long‐term culture (LTC)‐derived CFU, (2) expand in primary and secondary LTC, and (3) generate multiple cell lineages. In 21 cancer patients who had undergone autologous PBSC transplantation, the number of infused SSCloALDHbr cells/kg highly correlated with the time to neutrophil and platelet engraftment (P < 0·015 and P < 0·003 respectively). In summary, peripheral blood SSCloALDHbr cells have the phenotypic and functional properties of primitive haematopoietic cells and their number correlates with engraftment following autologous transplantation.
Management of the Surgical Patient with End‐Stage Renal Disease
Authors: Friedman Amy L.
Published: June 2003

For health providers guiding the end‐stage renal disease patient's care, conventional surgical and anesthetic principles may demand substantial modifications to optimize both the immediate outcome and long‐term survival. Elective operation is conducted in the setting of optimized acid/base balance, volume status and potassium management with pre‐operative dialysis completed within 24 hours of the procedure (either hemodialysis or peritoneal dialysis). When peripheral intravenous access is inadequate, central venous access is obtained preferentially through the internal jugular veins because of the catastrophic consequences of catheter‐induced subclavian stenosis. Infectious prophylaxis incorporates antibiotic selection considering the lack of native renal drug clearance, the potential for drug loss across dialysis membranes and potential interactions with immunosuppressive medications. Judicious intraoperative blood and fluid replacement should not be so restricted as to permit inadequate end organ perfusion, even if post‐operative dialysis is necessitated. Hemostasis may be facilitated by the use of desmopressin to correct uremic platelet dysfunction. Wound closure techniques should accommodate the delayed healing associated with kidney failure and/or iatrogenic immunosuppression.
Additional molecular bases of the clinically important p blood group phenotype
Authors: Hellberg Åsa , Steffensen Rudi , Yahalom Vered , Sojka Birgitta Nilsson , Heier Hans Erik , Levene Cyril , Poole Joyce , Olsson Martin L.
Published: June 2003

BACKGROUND: The purpose of this study was to explore the molecular basis of the p phenotype by analysis of the recently cloned 4‐α‐galactosyltransferase gene responsible for synthesis of Pk (Gb3) antigen.

STUDY DESIGN AND METHODS: Forty samples from individuals of eight different nationalities were investigated by serologic methods and DNA sequencing of the Pk gene.

RESULTS: Ten different Pk‐null alleles, of which 6 are novel, were encountered. The 29 Swedes were homozygous for M183K or G187D, with the former as the predominant allele. Three Israelis were homozygous for a single‐nucleotide deletion at codon 219 that shifts and truncates the reading frame by 5 amino acids. Two Italians were homozygous for a triplet deletion causing F81del, while an English donor was heterozygous for F81del but also carried another allele with a combined deletion and insertion. A Pole was heterozygous for alleles with either a single‐base deletion at codon 257 or a mutation causing S97L. A Norwegian person and a Japanese person were homozygous for single‐base insertions causing a premature stop at codon 282 or extension of the protein by 92 residues, respectively. In 2 samples no mutations were detected.

CONCLUSION: The genetic heterogeneity underlying the p phenotype is further emphasized by this study. To date, 11 p‐specific mutations have been found in 14 distinct alleles.
The importance of antibodies against low‐incidence RBC antigens in complete and abbreviated cross‐matching
Authors: Schonewille Henk , Zijl Annette M. van , Wijermans Pierre W.
Published: June 2003

BACKGROUND: It is common practice to perform an antiglobulin cross‐match only when unexpected RBC alloantibodies are present, to detect antibodies against additional RBC antigens. In this study, the incidence of unexpected antibodies to low‐incidence antigens (Ab‐LIA) over a period of 23 years was investigated.

STUDY DESIGN AND METHODS: Records of RBC antibodies and the accompanying transfusion history from 1978 through 2000 was retrospectively examined. Complete cross‐matches were performed for all RBC transfusions before 1991. As of 1991, the type‐and‐screen policy was applied. To study the incidence of anti‐Wra, a prospective study was conducted on sera from 462 patients sent to the transfusion laboratory and 486 blood donors.

RESULTS: The records of 1795 patients containing 2257 RBC antibodies were examined. In 89 patients, a total of 94 Ab‐LIAs was found. Anti‐Wra was the most frequently encountered Ab‐LIA. Thirty‐nine patients had Ab‐LIA in combination with other antibodies, 20 of which were autoantibodies. Eighty percent of these Ab‐LIA were found at the first positive antibody screening test. Fifty‐one solitary Ab‐LIA were found in 50 patients, 37 during antibody screening tests, and 14 after positive complete cross‐matches conducted before 1991. After an RBC antibody was detected, 664 patients received a total of 7792 RBC transfusions. Since the introduction of the type‐and‐screen policy, only one anti‐Wra has been discovered during complete cross‐matching. No transfusion reactions due to Ab‐LIA were reported during the study period. In the prospective study, 12.3 percent of patients and 4.3 percent of blood donors had anti‐Wra.

CONCLUSIONS: Although Ab‐LIAs are found coincidentally in the sera of only 2 to 3 percent of patients with other RBC antibodies, they are formed often. Because we found no difference in serologic incompatibility, due to Ab‐LIAs, between patients with and without other blood group antibodies, we conclude that blood can be transfused safely to patients without performing a complete cross‐match.
e‐Courseware authoring tools for teaching electrodynamics
Authors: Baumgartner U. , Grumer M. , Jaindl M. , Köstinger A. , Magele Ch. , Preis K. , Reinbacher M. , Voller S.
Published: June 2003

Nowadays, there are strong movements towards development and usage of multimedia courseware as a means of knowledge transfer. Many authors of textbooks or lecture notes are now striving to redesign the supporting material for their major courses in a structured, highly efficient way, including interactive content and media. Thus, in order to avoid unnecessary work load resulting from updating and publishing various courseware versions, tools for improving document creation and conversion have been developed and are now being applied for the first time on a new “Electrodynamics”‐‐ courseware.
Path-Integral Quantum Transport Equation for the Study of Homogeneous Semiconductors
Authors: Schulz-Mirbach C.
Published: June 2003

Based on perturbation theory for real-time Feynman path-integrals, we derive a quantum transport equation for an electron in a semiconductor that uses a time-discretized formulation of the Feynman kernel in momentum space for the inclusion of scattering processes of any kind on the level of matrix-elements of the perturbing potential. The movement of the electron in the electric field is accounted for by the analytical solution of the homogeneous problem while the scattering processes are accounted for in a statistical procedure. We apply the method to calculate the momentum and energy distribution function for homogeneous GaAs.
The Influence of Long-Range Hopping on Ferromagnetism in the Hubbard Model
Authors: Farkašovský Pavol
Published: June 2003

The phase diagram of the Hubbard model in an external magnetic field is examined by extrapolation of small-cluster exact-diagonalization calculations. Using a general expression for the hopping matrix elements (tij ~ q|i-j|) the influence of long-range hopping (band asymmetry) on ferromagnetism in this model is studied. It is found that the long-range hopping (nonzero q) stabilizes ferromagnetism in an external magnetic field for n > 1. In the opposite limit n≤1 the fully polarized ferromagnetic state is generally suppressed with increasing q. The critical value of magnetic field h below which the ferromagnetic state becomes unstable is calculated numerically.
The Cumulant Expansion for the Anderson Lattice with Finite U: The Completeness Problem
Authors: Foglio M. E. , Figueira M. S.
Published: June 2003

"Completeness" (i.e. probability conservation) is not usually satisfied in the cumulant expansion of the Anderson lattice when a reduced state space is employed for U → ∞. To understand this result, the well known "Chain" approximation is first calculated for finite U, followed by taking U → ∞. Completeness is recovered by this procedure, but this result hides a serious inconsistency that causes completeness failure in the reduced space calculation. Completeness is satisfied and the inconsistency is removed by choosing an adequate family of diagrams. The main result of this work is that using a reduced space of relevant states is as good as using the whole space.
Floquet Energies and Quantum Hall Effect in a Periodic Potential
Authors: Ferrari Ruggero
Published: June 2003

The Quantum Hall Effect for free electrons in external periodic potential is discussed without using the linear response approximation. We find that the Hall conductivity is related in a simple way to Floquet energies (associated to the Schrödinger equation in the co-moving frame). By this relation one can analyze the dependence of the Hall conductivity from the electric field. Subbands can be introduced by the time average of the expectation value of the Hamiltonian on the Floquet states. Moreover we prove previous results in form of sum rules as, for instance: the topological character of the Hall conductivity (being an integer multiple of e2/h), the Diofantine equation which constrains the Hall conductivity by the rational number which measure the flux of the magnetic field through the periodicity cell. The Schrödinger equation fixes in a natural way the phase of the wave function over the reduced Brillouin zone: thus the topological invariant providing the Hall conductivity can be evaluated numerically without ambiguity.
On the Collective Mode Spectrum in FQHE
Authors: Cabo Alejandro , Martínez Aurora Pérez
Published: June 2003

We consider the Bethe Salpeter Equation (BSE) for a fractionally filled Landau level. A phenomenological discussion of the 1/3 Laughlin's state is performed by assuming an ansatz for the one-particle propagator. The BSE is solved in this approach and it predicts an instability under the formation of charge density oscillations for a wide range of the one-particle gap parameter values in contrast with previous single mode approximation results. However, the conclusion is compatible with the one obtained within a composite fermion description done by us before and with the saturation of the zero momentum oscillator strength sum rule by the cyclotronic resonance. Further studies should be done in order to understand the discrepancy.
Theory of Extremal Dynamics with Quenched Disorder: Self-Organization, Avalanche Dynamics and Critical Exponents
Authors: Cafiero R. , Pietronero L. , Gabrielli A. , Marsili M.
Published: June 2003

In this paper we discuss a general theoretical scheme, that we have recently proposed, for a class of phenomena characterized by extremal dynamics with quenched disorder. The approach is based on a transformation of the quenched dynamics into a stochastic dynamics with cognitive memory. This transformation, together with other concepts, permits a mathematical characterization of the self-organized nature of the avalanche type dynamics. By combining the mapping with real space methods, like the fixed scale transformation (FST), it is also possible to compute the relevant critical exponents directly from the microscopic model. A specific application to Invasion Percolation is presented but the approach can be easily extended to various other problems with quenched disorder.
Forecasting for a Remote Island: A Class Exercise
Authors: Riordan Allen J.
Published: June 2003

Students enrolled in a satellite meteorology course at North Carolina State University, Raleigh, recently had an unusual opportunity to apply their forecast skills to predict wind and weather conditions for a remote site in the Southern Hemisphere. For about 40 days starting in early February 2001, students used satellite and model guidance to develop forecasts to support a research team stationed on Bouvet Island (54°26′S, 3°24′E). Internet products together with current output from NCEP's Aviation (AVN) model supported the activity. Wind forecasts were of particular interest to the Bouvet team because violent winds often developed unexpectedly and posed a safety hazard.

Results were encouraging in that 24-h wind speed forecasts showed reasonable reliability over a wide range of wind speeds. Forecasts for 48 h showed only marginal skill, however. Two critical events were well forecasted—the major February storm with wind speeds of over 120 kt and a brief calm period following several days of strong winds in early March. The latter forecast proved instrumental in recovering the research team.
Students' Motivations for Data Handling Choices and Behaviors: Their Explanations of Performance
Authors: Keiler Leslie , Woolnough Brian
Published: June 2003

Cries for increased accountability through additional assessment are heard throughout the educational arena. However, as demonstrated in this study, to make a valid assessment of teaching and learning effectiveness, educators must determine not only what students do, but also why they do it, as the latter significantly affects the former. This study describes and analyzes 14- to 16-year-old students' explanations for their choices and performances during science data handling tasks. The study draws heavily on case-study methods for the purpose of seeking an in-depth understanding of classroom processes in an English comprehensive school. During semistructured scheduled and impromptu interviews, students were asked to describe, explain, and justify the work they did with data during their science classes. These student explanations fall within six categories, labeled 1) implementing correct procedures, 2) following instructions, 3) earning marks, 4) doing what is easy, 5) acting automatically, and 6) working within limits. Each category is associated with distinct outcomes for learning and assessment, with some motivations resulting in inflated performances while others mean that learning was underrepresented. These findings illuminate the complexity of student academic choices and behaviors as mediated by an array of motivations, casting doubt on the current understanding of student performance.
Extrusion of ultrahigh molecular weight polyethylene under ultrasonic vibration field
Authors: Liu Gongde , Li Huilin
Published: June 2003

The effects of polypropylene (PP) and ultrasonic irradiation on the processing and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) are studied. The results show that PP can effectively improve the fluidity and mechanical properties of UHMWPE. The Izod notched impact strength increases from 92 kJ/m2 for pure UHMWPE to 109.2 kJ/m2 for the blend of UHMWPE with 10 wt % PP. The Young's modulus increases from 528 MPa for pure UHMWPE to 1128 MPa when 25 wt % PP is contained in the blend, and the yield strength also rises when PP is added. The application of ultrasonic vibrations during extrusion can prominently decrease the die pressure and apparent viscosity of the melt, thus increasing the output of extrudate. An appropriate ultrasonic intensity and irradiation time can further promote the mechanical properties, while an overdose of irradiation destroys them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2628–2632, 2003
Some properties of polyethylene–heptadecane mixtures
Authors: Shlyapnikov Yury A. , Kolesnikova Natalya N.
Published: June 2003

A mixture of high‐density polyethylene and its low‐molecular‐weight analogue heptadecane was studied. The mixture behaved as a compound, that is, differently from polyethylene. Heptadecane reduced the crystallinity of polyethylene, and it intricately changed the concentration of centers sorbing phenyl‐β‐naphthylamine, the antioxidant, and simultaneously changed the equilibrium constant of sorption. Heptadecane also prolonged the duration of the antioxidant action in polyethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2597–2603, 2003
Synthesis and characterization of new polyureas based on 4‐(4′‐aminophenyl)urazole and various diisocyanates
Authors: Mallakpour Shadpour , Raheno Hossein
Published: June 2003

4‐(4′‐Aminophenyl)urazole (AmPU) was prepared from 4‐nitrobenzoic acid in six steps. The reaction of monomer AmPU with n‐isopropylisocyanate was performed in N,N‐dimethylacetamide solutions at different ratios, and the resulting disubstituted and trisubstituted urea derivatives were obtained in high yields and were finally used as models for polymerization reactions. The step‐growth polymerization reactions of AmPU with hexamethylene diisocyanate, isophorone diisocyanate, and toluene‐2,4‐diisocyanate were performed in N‐methylpyrrolidone solutions in the presence of pyridine as a catalyst. The resulting novel polyureas had inherent viscosities of 0.11–0.18 dL/g in dimethylformamide at 25°C. These polyureas were characterized with IR, 1H‐NMR, elemental analysis, and thermogravimetric analysis. Some physical properties and structural characterization of these novel polyureas are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2692–2700, 2003
Processability, rheology, and thermal, mechanical, and morphological properties of postconsumer poly(vinyl chloride) bottles and cables
Authors: Sombatsompop N. , Sungsanit K.
Published: June 2003

The processability, rheology, and thermal, mechanical, and morphological properties of three different commercial poly(vinyl chloride) (PVC) compounds blended with postconsumer PVC bottles and PVC cables were examined with respect to the recycled PVC content. The addition of PVC bottle recyclates [recycled bottles (RBs)] into virgin PVC bottle (VB) and virgin PVC pipe (VP) compounds caused a progressive reduction in the average torque. No thermal degradation or color change in the RB‐blended PVC compounds used was detected through carbonyl and polyene indices from IR analysis. The rheological properties for VP compounds were more sensitive to RB addition than those of VB compounds. The extrudate swell ratio did not change with the RB content. The decomposition temperature for the VB and VP compounds increased at 60–80% RB, whereas the glass‐transition temperature was unaffected by the RB loading. The 20 and 80 wt % RB loadings were recommended for the VB and VP compounds, respectively, for the optimum impact strength, the blends showing ductile fracture with a continuous phase. At the optimum impact and tensile properties, introducing RB recyclates into the VB compounds gave better results than the VP compounds. The hardness and density of the VB and VP compounds did not change with the RB content. The RB property change was comparatively faster than that of recycled PVC pipes. Adding the PVC cable recyclate [recycled cable (RC)] to virgin PVC cable (VC) had no obvious effect on the torque value of the RC/VC blends. The decomposition temperatures of the RC/VC blends stabilized at 20–60% RC and tended to decrease at 80% RC. The ultimate tensile stress was improved by the addition of the RC compounds, whereas the hardness and density of the VC compounds were unaffected by the RC content. It was concluded that the optimum concentrations of PVC recyclates to be added to virgin PVC compounds were different from one property to another and also depended on the type of virgin PVC grade used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2738–2748, 2003
Maximum likelihood constrained deconvolution. II: Application to experimental two‐ and three‐dimensional NMR spectra
Authors: Jeong Gwang‐Woo , Kang Heoung‐Keun
Published: June 2003

The maximum likelihood method (MLM) and related protocols were applied to the experimental 2‐D nuclear Overhauser effect (NOE) spectrum of a 24‐nucleotide RNA hairpin loop molecule. The output becomes more valuable when diagonal symmeterization is followed by MLM. This symmeterized maximum likelihood (SML) protocol restores the original spectral information with high fidelity by accurately partitioning components from overlapped peaks and provides substantial improvements in line shape and spectral resolution, in particular in the F1 dimension. These advantages lead to a simpler interpretation of the resonance frequencies, intensities, multiplet fine structure, and J‐coupling values from a heavily overlapped peak region. This promises a more effective tool for peak picking, assignment, and integration. Also, application of MLM and related protocols to the 2‐D NOE proton spectrum of a 24‐mer RNA dramatically increases the number of NOE‐based distance constraints that can be used for determination of its 3‐D molecular structure. By application of 3‐D MLM to a simple 3‐D spectrum, the spectral resolution and signal‐to‐noise (S/N) ratio was greatly improved by effective line sharpening and reduction of cross‐talk between planes. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 18A: 146–156, 2003
Suppressor activity of anergic T cells induced by IL‐10‐treated human dendritic cells: association with IL‐2‐ and CTLA‐4‐dependent G1 arrest of the cell cycle regulated by p27Kip1
Authors: Kubsch Sebastian , Graulich Edith , Knop Jürgen , Steinbrink Kerstin
Published: June 2003

We have previously shown that human IL‐10‐treated dendritic cells (DC) induce an antigen‐specific anergy in CD4+ T lymphocytes. These anergic T cells are characterized by an inhibitedproliferation, a reduced production of IL‐2, and additionally display antigen‐specific suppressor activity. In this study we investigated the mechanisms underlying the anergic state and regulatory function of these T cells. We did not observe enhanced rates of programmed cell death of anergic CD4+ suppressor T cells compared to T cells stimulated with mature DC. Cell cycle analysis by DNA staining and Western blot experiments revealed an arrest of anergic CD4+ T suppressor cells in the G1 phase. High levels of the IL‐2‐dependent cyclin‐dependent kinase (cdk) inhibitor p27Kip1 were found in anergic CD4+ suppressor T cells resulting in an inhibited activation of retinoblastoma protein and an arrest of cell cycle progression in the G1 phase. Addition of IL‐2, but not blocking of the CTLA‐4 pathway restored the proliferation of the suppressor T cells. In contrast, both treatments induced a down‐regulation of p27Kip1 and acomplete inhibition of the antigen‐specific regulatory function as demonstrated by high proliferation and enhanced IFN‐γ production of co‐cultured T cells. Further experiments demonstrated thatp27Kip‐expressing regulatory CD4+CD25+ T cells did not contribute to induction of T cell anergy in this model. Our data show that regulatory function of anergic CD4+ suppressor T cells is associated with an arrest in the G1 phase of the cell cycle mediated by increased levels of the IL‐2‐ and CTLA‐4‐dependent cdk inhibitor p27Kip1.
Essential role for IKKγ/NEMO in TCR‐induced IL‐2 expression in Jurkat T cells
Authors: He Kai‐Li , Ting Adrian T.
Published: June 2003

The control of IL‐2 gene expression in T cells by multiple transcriptional factors has been extensively explored, however, the role of the NF‐κB signaling pathway in TCR‐dependent IL‐2 production still remains unclear. In this study, we used a somatic cell genetics approach to address this question. Triggering TCR in mutant Jurkat T cells lacking IKKγ/NEMO failed to induce IL‐2due to a selective loss in I‐κB kinase activity, I‐κBα degradation and NF‐κB DNA‐binding activity. The AP‐1 and NF‐AT binding activities in the IL‐2 promoter were comparable between wild‐type and mutant T cells. These defects in the mutant cell line were rescued by the reintroduction of exogenous IKKγ. Taken together, our data demonstrate that IKKγ plays an essential role in TCR‐induced signaling pathways leading to IL‐2 expression.
Nucleosomes induce lymphocyte necrosis
Authors: Decker Patrice , Wolburg Hartwig , Rammensee Hans‐Georg
Published: June 2003

Nucleosomes are major autoantigens in systemic lupus erythematosus. These are found as circulating complexes in both lupus patients and lupus mice. The existence of a potential ubiquitous cellsurface receptor specific for nucleosomes has been suggested. However, neither the nature nor the role of this receptor has been identified. Moreover, the consequence of receptor‐nucleosome interaction on the target cell has not been studied in detail so far. We show here that purified nucleosomes induce cell death of normal and lupus lymphocytes ex vivo in a dose‐ and time‐dependentmanner whereas human dendritic cells were relatively resistant. Most importantly, nucleosome‐induced cell death is primary necrosis. Moreover, necrosis could be abolished when nucleosomes were first treated with deoxyribonuclease I, proteinase K or with a specific monoclonal antibody. Finally, intravenous injections of purified nucleosomes result in a reduced spleen cell number compared to buffer‐injected mice, indicating that circulating nucleosomes may behave similarly in vivo. Taken together, this is the first report indicating that nucleosomes are able to induce necrosis,which in turn could result in an amplification loop of the disease causing the inflammation observed in lupus patients.
Correction: Strong antigenic selection shaping the immunoglobulin heavy chain repertoire of B‐1a lymphocytes in λ2315 transgenic mice (Eur. J. Immunol. 7/2003)
Authors: Kretschmer K. , Engel H. , Weiss S.
Published: June 2003

Vol. 32(8) 2002, pp 2317‐2327

The following information was missing in the figure legends:

Figure 3: The complete sequence data from non‐Tg and L2 mice are available from GenBank under accession no. AY173963‐AY174047 and AY182378‐AY182378, respectively.

Figure 5: The complete sequence data are available from GenBank under accession no. AY182489‐AY182533 (non‐Tg fetal liver), AY182599‐AY182636 (L2 FL), AY182697‐AY182717 (L2 neonatal liver, Exp. 1), AY182718‐AY182754 (L2 neonatal liver, Exp. 2), AY182555‐AY182598 (VH‐gene specific amplification from L2 day 1 liver) and AY182489‐AY182533 (non‐Tg FL).

Figure 6: The sequence data from in vitro differentiated non‐Tg and Tg Pro/PreB cells are available from GenBank under accession no. AY182534‐AY182554 and AY182637‐AY182696, respectively.
In situ gene transfer into animal tendons by injection of naked DNA and electrotransfer
Authors: Jayankura Marc , Boggione Christophe , Frisén Charlotte , Boyer Olivier , Fouret Pierre , Saillant Gérard , Klatzmann David
Published: June 2003

Background

Degenerative or traumatic tendon injuries are extremely common but often heal poorly, not restoring the normal function of the injured tissues. Gene transfer could improve the repair process, by permitting local production of therapeutic substances, e.g. growth factors.

Methods and results

Injection of a plasmid carrying the lacZ marker gene was performed into the Achilles tendons of rat and mouse, and the patellar tendons of rabbit. At 48 h, transduced cells were found in the injected zones of the tendons but represented a minority of the tendon cells. A kinetics study in rats permitted observation of a gradual decrease with time in the β‐gal‐expressing cell number; at day 42 no more gene expression was detected. Noteworthy, no inflammatory reaction was observed. We then investigated whether electrotransfer could improve gene transfer efficacy in rat tendon by delivering in situ electric pulses after DNA injection. Gene transfer was improved at best by ≈50% under certain electrical conditions (200 V for 10 ms or 1200 V for 100 µs). Finally, multiple injections of plasmid permitted an increase in the number of transduced cells by ≈400%.

Conclusions

In situ injection of naked DNA into tendons is a very simple technique that permits delivery of genes with a duration of expression sufficient for clinical application aimed at modulating healing or restoration of a degenerative tendon. Despite a low transfer efficiency, this method should be compatible with clinical applications aimed at delivering therapeutic substances acting at low concentration. Copyright © 2003 John Wiley & Sons, Ltd.
pARMS: a parallel version of the algebraic recursive multilevel solver
Authors: Li Zhongze , Saad Yousef , Sosonkina Masha
Published: June 2003

A parallel version of the algebraic recursive multilevel solver (ARMS) is developed for distributed computing environments. The method adopts the general framework of distributed sparse matrices and relies on solving the resulting distributed Schur complement system. Numerical experiments are presented which compare these approaches on regularly and irregularly structured problems. Copyright © 2003 John Wiley & Sons, Ltd.
Formation mechanism of toroidal carbon nanotubes
Authors: Yang Linfeng , Jiang Jie , Dong Jinming
Published: June 2003

In order to study the formation mechanism of toroidal carbon nanotubes (TCNTs), we have examined their elastic energies by utilizing the continuum elastic theory. It is found that the allowed shapes of TCNTs should be determined by the constraint that the shape formation free energy should be equal to zero. We have also found that there exists a threshold condition under which a straight carbon nanotube will be curved and the TCNTs are one of the allowed shapes. The calculated torus radii for a toroidal multi‐wall carbon nanotube and single‐wall carbon nanotube bundle are in good agreement with the experimentally measured results. This indicates that the continuum elastic theory persists well into the small‐radius tubes and the formation of TCNT is a self‐organization process controlled by their shape formation free energy.
Transmission and backscattering energy distributions of slow electrons from metallic targets
Authors: Deghfel B. , Bentabet A. , Bouarissa N.
Published: June 2003

Transmission probabilities of slow electrons normally incident on aluminum and copper thin film targets are stochastically modeled within a Monte‐Carlo framework in the examined energy range 0.5–4 keV. Attention has also been given to transmission and backscattering energy distributions. The agreement between theory and experiment is found to be good in all cases.
Some details of the electronic structure of tin oxide films
Authors: Shcherba I. D. , Zakrzewska K. , Szuber J. , Czempic G. , Senkevich A. I. , Kravchenko I. I.
Published: June 2003

We present experimental results of electronic structure investigations of SnO2 films by X‐ray emission spectroscopy and X‐ray photoelectron spectroscopy methods wherein X‐ray O Kα emission spectra for these materials are reported for the first time. The O 2p electron band shifts toward the upper edge of the valence band when oxygen vacancies increase, but, at the same time, the distance on the binding energy scale from the O 2p band centroid to the Fermi level remains constant. The O 2p valence electron band is broader on the higher binding energy side for oxides having more oxygen vacancies.
Phonon drag thermopower in an AlGaN/GaN heterostructure
Authors: Kubakaddi S. S.
Published: June 2003

The theoretical thermopower of a two‐dimensional electron gas (2DEG) is studied in a clean AlGaN/GaN heterostructure of zincblende (ZB) and wurtzite (WZ) symmetry over the temperature range 0.1–10 K. The phonon drag thermopower (Sg) due to 2DEG coupling with 3D longitudinal and transverse acoustic phonons is calculated for high‐density electrons. It is found that, in both ZB and WZ symmetries, the Sg due to piezoelectrically coupled transverse acoustic phonons is dominant over the Sg due to longitudinal acoustic phonons via piezoelectric and deformation potential coupling over the entire temperature range. This dominance is attributed to the pronounced piezoelectricity of nitrides and the smaller velocity of transverse acoustic phonons. It is shown that the total Sg ∼ Tn with n = 3.8 at temperatures T < 2.0 K and is close to n = 4 in the Bloch–Gruneisen limit. Diffusion thermopower (Sd) is also presented and is found to be significant for T below 0.4 K. The calculations are compared with the results for GaAs/GaAlAs heterostructures.
Pressure‐induced increase of exciton–LO‐phonon coupling in a ZnCdSe/ZnSe quantum well
Authors: Guo Z. Z. , Liang X. X. , Ban S. L.
Published: June 2003

The possibility of pressure‐induced increase of exciton–LO‐phonon coupling in ZnCdSe/ZnSe quantum wells is studied. The ground state binding energies of the heavy hole excitons are calculated using a variational method with consideration of the electron–phonon interaction and the pressure dependence of the parameters. The results show that for quantum wells with intermediate well width, the exciton binding energy and the LO‐phonon energy may coincide in the course of pressure increasing, resulting in the increase of exciton–LO‐phonon coupling. It is also found that among the pressure‐dependent parameters, the influence of the lattice constant is the most important one. The changes of both the effective masses and the dielectric constants have obvious effects on the exciton binding energy, but their influences are counterbalanced.
First principles total energy calculations of the structural and electronic properties of ScxGa1–xN
Authors: Moreno‐Armenta Maria Guadalupe , Mancera Luis , Takeuchi Noboru
Published: June 2003

Using first principles total energy calculations within the the full‐potential linearized augmented plane wave (FP‐LAPW) method, we have investigated the structural and electronic properties of ScxGa1–xN, with Sc concentrations varying from 0% up to 100%. In particular we have studied the relative stability of several configurations of ScxGa1–xN in wurtzite‐like structures (the ground state configuration of GaN), or in rocksalt‐like structures (the ground state configuration of ScN). It is found that for Sc concentrations less than ≈65%, the favored structure is a wurtzite‐like one, while for Sc concentrations greater than ≈65%, the favored structure is a NaCl‐like structure. It is also found that for the wurtzite‐like crystals, the fundamental gap is large and direct. For the rocksalt crystals the fundamental gap is small and indirect, but with an additional larger direct gap. In agreement with the experiments of Little and Kordesch [Appl. Phys. Lett. 78, 2891 (2001)] we found a decrease of the band gap with the increase of the Sc concentration.
Electron mobility in ZnSe single crystals
Authors: Avdonin A. N. , Nedeoglo D. D. , Nedeoglo N. D. , Sirkeli V. P.
Published: June 2003

Temperature dependence of electron mobility in n‐ZnSe single crystals is investigated in the temperature range 77–300 K. A comparative analysis of experimental data with the known theoretical dependences calculated using solution of the Boltzmann transport equation and taking into consideration all major scattering mechanisms and screening effects is carried out. The good agreement between the experimental and theoretical dependences of electron mobility on both temperature and electron concentration is observed for the samples with various compensation ratios. It is shown that parameters such as the ionized impurity concentration and acceptor concentration can quickly be estimated for strongly compensated samples.
Environmental response to intentional dissemination of Bacillus anthracis spores in the United States–2001
Authors: Barth Edwin , Rupert Richard , Stroud Fred , Rice Eugene , Potoka Bruce
Published: June 2003

The intentional dissemination of Bacillus anthracis (anthrax) spores at multiple
locations in the United States in the fall of 2001 resulted not only in several deaths and illnesses
(including psychological effects), but likely changed lifestyles and attitudes, and increased the
public's awareness of individual vulnerability. While federal resources had previously been committed to
preparing local public health agencies for counter‐terrorism activities and to enhance environmental and
medical response, these release episodes have increased the consistency of environmental and medical response
activities, and increased government resources for homeland security. This article abstracts current information
from many sources that summarize the environmental responses to the anthrax releases. The article discusses the
international agreements and the U.S. regulations concerning biological weapons, the characteristics of the
anthrax organism, potential exposure pathways, adverse health conditions resulting from inhalation exposure, the
environmental response to two specific release episodes, environmental sampling and analytical procedures,
recommended personal protective equipment, and the subsequent federal efforts to improve response capabilities.
© 2003 Wiley Periodicals, Inc.
A custom‐fabricated device for chairside organization of multiple implant components
Authors: Toothaker Randy , Ashcraft Deborah , Soultanis Ioannis , Chang Myung W. Brian
Published: June 2003

Organizing multiple and varied implant components in preparation for providing treatment for a patient with a complex implant prosthesis can be a challenge to even the most experienced practitioner. The many implant abutment component options available, especially when different sizes and types of abutments will be used in 1 arch, can create confusion for both dentist and assistant, hindering chairside efficiency. This article describes the fabrication and use of a custom chairside implant components organizer.
Clinical evaluation of a new resilient denture liner. part 1: Compliance and color evaluation1
Authors: Villar Anamaria , Pesun Igor J. , Brosky Mary E. , Fines Casey , Hodges James S. , DeLong Ralph , Lai Juey H.
Published: June 2003

Purpose A new experimental resilient denture liner (MPDS‐SL; Lai Laboratories, Burnsville, MN) and Molloplast‐B (Buffalo Dental Manufacturing, Syosset, NY) were clinically evaluated for compliance and color change over a 1‐year period.

Materials and Methods In this crossover study, each of 20 patients had 2 dentures fabricated with long‐term, silicone‐based resilient liners, 1 denture with Molloplast‐B and the other with MPDS‐SL. Each denture was used for 6 months, during which time each patient kept a journal detailing his or her use and cleaning regimen. The 2 materials were assessed for compliance and color at the beginning of the study and again after 3 months and 6 months of use. Compliance was determined by applying a 3‐lb force to the surface of the material following a square‐wave pattern, using a closed‐loop servohydraulic testing system. The force and position values were recorded using a storage oscilloscope. Compliance was measured at 3 locations on each denture and analyzed using data‐acquisition software. Images of the dentures were captured using a zoom stereomicroscope with a charge‐coupled video camera and image analysis software. The color was measured at 3 locations on each denture; RGB and L* a* b* were calculated.

Results Compliance increased from baseline to 3 months and from 3 months to 6 months for almost all locations on both materials. Molloplast‐B and MPDS‐SL differed in average change in compliance at 6 months; the average change in compliance from baseline to 6 months was 453 (standard error, 46) for Molloplast‐B and 284 (standard error, 46) for MPDS‐SL (p= 0.019). For both materials, color changed significantly from baseline to 3 months and from baseline to 6 months (p <0.01). MPDS‐SL changed significantly less than Molloplast‐B from baseline to 6 months for R (p= 0.039), G (p= 0.037), B (p= 0.005), and L* (p= 0.042).

Conclusion For both materials, compliance increased over 6 months of wear. The color change for MPDS‐SL was considerably less significant than that for Molloplast‐B.
Modelling the climate evolution from the last interglacial to the start of the last glaciation: The role of Arctic Ocean freshwater budget
Authors: Khodri M. , Ramstein G. , Paillard D. , Duplessy J. C. , Kageyama M. , Ganopolski A.
Published: June 2003

The Earth's climate has alternated between glacial and interglacial stages, but we still do not understand how the changes in insolation have been amplified by the climate system to lead to such a large climatic response. Here we use a climate model of intermediate complexity to show that the orbitally induced shift from an interglacial to a pre‐glacial climate is highly sensitive to the high northern latitudes moisture budget. Using the insolation forcing alone, the model produces a first order response of sea surface temperatures and thermohaline circulation evolution which agrees with the available geological data. Under the same gradual insolation evolution, adding a small freshwater input into the Arctic Ocean induces a rapid climate switch from an interglacial to a pre‐glacial mode. These results suggest a simple connection between orbital forcing and the thermohaline circulation through a freshwater threshold within the ocean‐atmosphere‐sea‐ice system.