bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Exponents for the Model with Unique Stable Fixed Point From Three-Loop RG Expansions
Authors: Sokolov A. I. , Varnashev K. B. , Mudrov A. I.
Published: June 2003

The critical behavior of a model describing phase transitions in cubic and tetragonal anti-ferromagnets with 2N-component (N>1) real order parameters as well as the structural transition in NbO 2 crystal is studied within the field-theoretical renormalization-group (RG) approach in three and (4-∊)-dimensions. Perturbative expansions for RG functions are calculated up to three-loop order and resummed, in 3D, by means of the generalized Padé–Borel procedure which is shown to preserve the specific symmetry properties of the model. It is found that a stable fixed point does exist in the three-dimensional RG flow diagram for N>1, in accordance with predictions obtained earlier within the ∊-expansion. Fixed-point coordinates and critical-exponent values are presented for physically interesting cases N=2 and N=3. In both cases critical exponents are found to be numerically close to those of the 3DXY model. The analysis of the results given by the ∊-expansion and by the RG approach in three dimensions is performed resulting in a conclusion that the latter provides much more accurate numerical estimates.
Structure and oil‐resistant properties of HTPB‐based polyurea modified with polysulfide
Authors: Quan Yiwu , Wang Qingjun , Dong Wenzhao , Chen Qingmin
Published: June 2003

A series of hydroxy‐terminated polybutadiene (HTPB) polyureas modified with different liquid polysulfide content was synthesized and their structure and oil‐resistant properties were studied by attenuated total reflectance–FTIR spectroscopy, dynamic mechanical analysis, isothermal aging and differential scanning calorimetry, stress–strain analysis, oil absorption, and oil‐resistance test. The results showed that polysulfide–polybutadiene polyureas retained low temperature flexibility and had lower oil absorption and better oil resistance than that of HTPB‐based polyureas. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2672–2675, 2003
Soap‐free cationic emulsion copolymerization of styrene and butyl acrylate with comonomer in the presence of alcohols
Authors: Zhang Jinzhi , Zou Qichao , Li Xiaoqin , Cheng Shiyuan
Published: June 2003

Preparation of a cationic polymer latex of styrene and butyl acrylate with comonomer N,N‐dimethyl, N‐butyl,N‐methacryloloxylethyl ammonium bromide (DBMEA) was carried out by soap‐free emulsion polymerization. The effect of reaction conditions such as the ratio of methanol to water, DBMEA concentration, AIBA concentration and ionic strength on properties of copolymer particles was studied. The results showed that the average diameter (Dw) decreased with increasing of AIBA and DBMEA concentration; Dw decreased first then increased with increasing of methanol content; variation of the ionic strength led to a variation in the particle number (Np) and Dw because of the competition of two kinds of nucleation mechanisms. The same trend was found in the polymerization taking in pure water. The MWD was bimodal during the particle growth period. These results suggest that the particles can be generated through two particle‐formation mechanisms, micelle nucleation and homogeneous nucleation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2791–2797, 2003
Synthesis and characterization of novel polyfuran/poly(2‐iodoaniline) conducting composite
Authors: Gök Ayşegül , Sarı Bekir , Talu Muzaffer
Published: June 2003

The electrically conducting polyfuran/poly(2‐iodoaniline) (PFu/P2IAn) and P2IAn/PFu composites were prepared by chemical oxidative polymerization using polyfuran and poly(2‐iodoaniline) in HCl and CHCl3 media. The conductivities of composites were determined as a function of the amount of guest polymer. It was found out that the conductivities of P2IAn/PFu composites increased 100‐fold, whereas the conductivities of PFu/P2IAn composites did not show a specific increase. The composite compositions were altered by varying guest polymer feed ratios during preparation. Generally, the electrical conductivities of P2IAn/PFu composites increased with increasing the amount of PFu. Homopolymers and composites were further characterized thermally, employing thermogravimetry (TGA) and morphologically employing scanning electron microscopy (SEM). Further evidences concerning the polymer structures were obtained by FTIR and UV‐vis spectroscopies and magnetic susceptibility measurements. TGA results revealed that PFu/P2IAn among the homopolymers (PFu and P2IAn) and P2IAn/PFu composite have the highest thermal stability. The composites synthesized varying the host and the guest polymer order have different conductivities, morphological structures, and thermal properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2823–2830, 2003
Methodological development of solid‐state NMR for characterization of membrane proteins
Authors: Bjerring M. , Vosegaard T. , Malmendal A. , Nielsen N.C.
Published: June 2003

Solid‐state NMR is a promising method for structural analysis of membrane proteins. The method is capable of providing atomic‐resolution structure information without the need for crystals or fast molecular motion as is required for X‐ray diffraction and liquid‐state NMR, respectively. However, it is clear that solid‐state NMR still needs substantial methodological development before it can provide the desired detailed information about large structures or be applied routinely for structure–function relationship studies. Here, we address some important considerations and elements in the solid‐state NMR methodology relevant for characterization of membrane proteins. These are relevant for establishing the appropriate technology and may serve as an inspiration for future developments in synthesis, isotope labeling, and physical preparation of samples for solid‐state NMR characterization. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson 18A: 111–129, 2003
Type‐1 polarized nature of mouse liver CD8α– and CD8α+ dendritic cells: tissue‐dependent differences offset CD8α‐related dendritic cell heterogeneity
Authors: O'Connell Peta J. , Son Young‐Ik , Giermasz Adam , Wang Zhiliang , Logar Alison J. , Thomson Angus W. , Kalinski Pawel
Published: June 2003

Interleukin‐12 p70 (IL‐12p70) is a major dendritic cell (DC)‐produced cytokine known to support type‐1 T helper (Th1) cells and inflammatory‐type immunity. While the ability of DC to produce bioactive IL‐12p70 depends on both the DC subtype and the microenvironmental conditions of DC development, the relative contribution of each of these factors remains unclear. Here, we report that in contrast to spleen CD8α+ and CD8α– DC that show strong differences in their respective IL‐12p70‐producing capacities, CD8α+ and CD8α– DC isolated from the liver, a non‐lymphoid organ, both efficiently produce IL‐12p70 in amounts comparable to spleen CD8α+ DC. The IL‐12p70‐producing capacity of CD8α+ and CD8α– DC from either location is greatly increased following their overnight culture in the presence of granulocyte‐macrophage colony‐stimulating factor. The elevated production of IL‐12p70 by short‐term cultured DC correlates with their enhanced expression of CD40 and other costimulatory molecules, and elevated T cell‐stimulatory capacity. These data indicate that low IL‐12‐producing capacity is not an intrinsic property of the CD8α– DC subtype, and support the hypothesis that factors such as the site of DC development and maturation stage play a dominant role in defining DC function.
Using geostatistics to elucidate temporal change in the spatial variation of aeolian sediment transport
Authors: Chappell Adrian , Mctainsh Grant , Leys John , Strong Craig
Published: June 2003

Little is known about the spatial and temporal scales of variation in aeolian processes. Studies that aim to investigate surface erodibility often sample aeolian sediment transport at the nodes of a regular grid of arbitrary size. Few aeolian transport investigations have the resources to obtain sufficient samples to produce reliable models for mapping the spatial variation of transport. This study reports the use of an innovative nested strategy for sampling multiple spatial scales simultaneously using 40 sediment samplers. Reliable models of the spatial variation in aeolian sediment transport were produced and used for ordinary punctual kriging and stochastic simulated annealing to produce maps for several wind erosion events over a 25 km2 playa in western Queensland, Australia. The results support the existence of a highly dynamic wind erosion system that was responding to possibly cyclic variation in the availability of material and fluctuations in wind energy. The spatial scale of transport was considerably larger than the small scale expected of the factors controlling surface erodibility. Thus, it appears that transport cannot be used as a surrogate of erodibility at the scale of this investigation. Simulation maps of transport provided considerably more information than those from kriging about the variability in aeolian sediment transport and its possible controlling factors. The proposed optimal sampling strategy involves a nested approach using ca 50 samplers. Copyright © 2003 John Wiley & Sons, Ltd.
Recent channel adjustments in alluvial rivers of Tuscany, central Italy
Authors: Rinaldi Massimo
Published: June 2003

Drastic channel adjustments have affected the main alluvial rivers of Tuscany (central Italy) during the 20th century. Bed‐level adjustments were identified both by comparing available topographic longitudinal profiles of different years and through field observations. Changes in channel width were investigated by comparing available aerial photographs (1954 and 1993–98).

Bed incision represents the dominant type of vertical adjustment, and is generalized along all the fluvial systems investigated. The Arno River system is the most affected by bed‐level lowering (up to 9 m), whereas lower incision (generally less than 2 m) is observed along the rivers of the southern part of the region. Human disturbances appear to be the dominant factors of adjustments: the main phase of vertical change occurred during the period 1945–80, in concomitance with the phase of maximum sediment mining activity at the regional scale.

The second dominant type of adjustment that involved most of the rivers in the region consists of a narrowing of the active channel. Based on measurements of channel width conducted on aerial photographs, 38% of the reaches analysed experienced a narrowing greater than 50% of the initial channel width. The largest values of channel narrowing were observed along initially braided or sinuous with alternate bars morphologies in the southern portion of the region.

A regional scheme of channel adjustments is derived, based on initial channel morphology and on the amounts of incision and narrowing. Different styles of channel adjustments are described. Rivers that were originally sinuous with alternate bars to braided generally became adjusted by a moderate incision and a moderate to intense narrowing; in contrast, sinuous‐meandering channels mainly adjusted vertically, with a minor amount of narrowing. Copyright © 2003 John Wiley & Sons, Ltd.
Grid transfer operators for highly variable coefficient problems in two‐level non‐overlapping domain decomposition methods
Authors: Giraud L. , Guevara Vasquez F. , Tuminaro R. S.
Published: June 2003

We propose a robust interpolation scheme for non‐overlapping two‐level domain decomposition methods applied to two‐dimensional elliptic problems with discontinuous coefficients. This interpolation is used to design a preconditioner closely related to the BPS scheme proposed in [Bramble et al. (Math. Comput. 1986; 47(175):103)]. Through numerical experiments, we show on structured and unstructured finite element problems that the new preconditioning scheme reduces to the BPS method on smooth problems but outperforms it on problems with discontinuous coefficients. In particular it maintains good scalable convergence behaviour even when the jumps in the coefficients are not aligned with subdomain interfaces. Copyright © 2003 John Wiley & Sons, Ltd.
Electronic properties of Si/SiGe ultrathin quantum wire superlattices
Authors: Benkhettou N. , Rached D. , Sekkal N.
Published: June 2003

The electronic bandstructure of ultrathin Si/Si1–xGex quantum wire superlattices is investigated using two methods. The first is the pseudopotential method of M. Jaros. The second is the first‐principles method of full potential linear muffin‐tin orbitals (FP‐LMTO) coupled to a plane‐wave basis (PLW) in the interstitial regions, which is employed to verify the results obtained with the previous method. Larger quantum wire superlattices (but always ultrathin) are also investigated. The most important result is that one of these systems is found to be promising for optoelectronic applications.
Impact of stress and long‐range interaction on ultrathin ferroelectric films
Authors: Cao Hai‐Xia , Wu Yin‐Zhong , Dong Wen , Li Zhen‐Ya
Published: June 2003

Based on the Landau–Devonshire type theory, the polarization, critical thickness, pyroelectric coefficient and correlation length of epitaxial ultrathin ferroelectric BaTiO3 films with first‐order phase transition have been investigated using the finite difference method. The theory not only allows for the influence of the stress attributed to lattice constant misfit between the ferroelectric film and the thick substrate, but also takes into account the long‐range dipole–dipole interactions. It is shown that both the compressive stress and the long‐range interaction increase the polarization and the Curie temperature, which can be compared with the experimental results, whereas the tensile stress reduces the polarization. In addition, both the stress and long‐range interaction remarkably affect the pyroelectric coefficient and the correlation length.
Geological and geochemical legacy of a cold early Mars
Authors: Gaidos Eric , Marion Giles
Published: June 2003

We consider the hypothesis that Mars never experienced an early warm, wet period and the implications of a continuously cold Martian climate for the hydrology and geochemistry of the planet. Geomorphic evidence previously interpreted to indicate a more temperate early climate can be explained by cold climate processes and the transient flow of liquid water at the surface rather than a terrestrial‐like hydrological cycle. In this scenario, freezing and confinement of crustal aquifers lead to the eruption of water or brines to the surface: Hesperian events formed massive ice sheets, and triggered floods that carved the outflow channels, while smaller, present‐day aqueous eruptions are responsible for the seepage and gully‐like landforms identified in high‐resolution imaging. This process may have fluxed a significant volume of groundwater to the surface and the polar caps. A primordial source of groundwater reconciles the present D/H isotopic ratio of the atmosphere with fractionating atmospheric escape and a primordial Martian D/H inferred from hydrous phases of SNC meteorites. A cold early climate and a thin CO2 atmosphere are consistent with the ubiquity of primary igneous minerals and the apparent absence of secondary minerals and copious carbonates on the surface. Aqueous eruptions introduced soluble chloride and sulfate salts into Martian soils, leaving clays and carbonates within the crust. If the Martian crust hosts a “deep biosphere,” aqueous eruptions can bring organisms or their chemical signature to the surface. The biotic component of any recent eruptions may be preserved in transient ice in cold traps on the surface.
Living related kidney transplantation in a patient with autosomal‐recessive Alport syndrome
Authors: Sakai Ken , Muramatsu Masaki , Ogiwara Hidetaka , Kawamura Takeshi , Arai Kenji , Aikawa Atsushi , Ohara Takehiro , Mizuiri Sonoo , Joh Kensuke , Naito Ichiro , Hasegawa Akira
Published: June 2003

Abstract:  We discuss a patient with Alport syndrome who received a renal transplant from a donor with thin basement membrane disease. A 30‐year‐old woman, diagnosed with Alport syndrome on the basis of sensorineural hearing loss, characteristic renal biopsy findings and a family history of microhaematuria, entered chronic haemodialysis therapy. She then received a renal transplant donated from her father, who had sensorineural hearing loss and persistent microhaematuria. On the day of renal transplantation, a 1‐h graft biopsy after reperfusion showed thin basement membrane disease. We re‐tested the patient's native kidney biopsy specimen by immunohistochemical staining using α‐chain‐specific collagen type IV monoclonal antibodies. There was no expression of collagen type IV α3‐, α4‐ and α5‐chain on glomerular basement membrane, but positive staining of α5‐chain on Bowman's capsular basement membrane was noted. A diagnosis of autosomal‐recessive Alport syndrome was made. We concluded that this family might display different phenotypic expressions of the same genotype: one suffered end‐stage renal disease and the other thin basement membrane disease.
Acid inhibition on the first day of dosing: comparison of four proton pump inhibitors
Authors: Pantoflickova D. , Dorta G. , Ravic M. , Jornod P. , Blum A. L.
Published: June 2003

Background: Rapid and consistent acid suppression on the first day of dosing may be important in treating acid‐related disorders.

Aim: To compare the antisecretory activity and onset of action of single doses of rabeprazole, lansoprazole, pantoprazole, omeprazole capsule, omeprazole multiple unit pellet system (MUPS) tablet and placebo in healthy Helicobacter pylori‐negative subjects.

Methods: This cross‐over, double‐blind, randomized study was performed in 18 H. pylori‐negative subjects. Twenty‐four‐hour intragastric pH monitoring was performed on the day of treatment (once‐daily dose of rabeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, omeprazole capsule 20 mg, omeprazole MUPS tablet 20 mg or placebo).

Results: The intragastric pH (3.4) and time at pH > 4 during the 24 h post‐dose (8.0 h) were significantly greater with rabeprazole than with lansoprazole, pantoprazole, omeprazole capsule, omeprazole MUPS tablet or placebo (P ≤ 0.04 for rabeprazole vs. the others). Daytime and night‐time pH values were higher with rabeprazole and lansoprazole than with pantoprazole, omeprazole capsule and omeprazole MUPS tablet (P ≤ 0.04).

Conclusion: Rabeprazole was the most potent acid inhibitor of all the proton pump inhibitors tested during the first day of dosing.
Trans‐catheter arterial chemoembolisation for hepatocellular carcinoma in patients with viral cirrhosis: role of combined staging systems, Cancer Liver Italian Program (CLIP) and Model for End‐stage Liver Disease (MELD), in predicting outcome after treatment
Authors: Testa R. , Testa E. , Giannini E. , Botta F. , Malfatti F. , Chiarbonello B. , Fumagalli A. , Polegato S. , Podesta E. , Romagnoli P. , Risso D. , Cittadini G. , Caro G. DE
Published: June 2003

Background:  Trans‐catheter arterial chemoembolisation (TACE) is the most common palliative treatment for hepatocellular carcinoma (HCC). The therapeutic options depend both on the characteristics of the tumour and on functional staging of the cirrhosis.

Aim:  To evaluate the effects of TACE on the survival of cirrhotic patients with HCC according to different staging systems [Okuda score, Cancer Liver Italian Program (CLIP) score, Model for End‐stage Liver Disease (MELD) score] and in relation to the side‐effects of TACE.

Methods:  Fifty cirrhotic patients, 36 CTP class A and 14 class B, underwent 106 TACE treatments with mitoxantrone. Survival at 12, 24, and 36 months was evaluated.

Results:  MELD at 12 months and CLIP at 24 months were identified as significant variables associated with survival. Combined cut‐offs of CLIP and of MELD identified four subgroups of patients with different survivals, at 12, 24 and 36 months, respectively: CLIP ≥ 2 and MELD ≥ 10 (63%, 20% and 0%), CLIP < 2 and MELD ≥ 10 (73%, 40% and 22%), CLIP ≥ 2 and MELD < 10 (73%, 40% and 22%) and CLIP < 2 and MELD < 10 (100%, 63% and 50%). Post‐TACE side‐effects proved to have no influence on survival.

Conclusion:  In patients with poor probability of survival (CLIP ≥ 2 and MELD ≥ 10), TACE must be planned with a great deal of caution, while in patients with possibly good outcomes (CLIP < 2 and MELD < 10), more ‘aggressive’ therapy should be taken into consideration.
C‐reactive protein: associations with haematological variables, cardiovascular risk factors and prevalent cardiovascular disease
Authors: Woodward Mark , Rumley Ann , Lowe Gordon D. O. , Tunstall‐Pedoe Hugh
Published: June 2003

Summary. C‐reactive protein (CRP) has been proposed as a risk factor for cardiovascular disease; however, this association is confounded by mutual relationships with both classical and haematological cardiovascular risk factors. We, therefore, measured CRP with a high‐sensitivity assay in stored plasma samples from 414 men and 515 women in the north Glasgow MONICA (MONItoring trends in CArdiovascular diseases) survey, to study its correlation with haematological variables, classical risk factors and prevalent cardiovascular disease. CRP correlated with age, oral contraceptive use, menopause and most classical cardiovascular risk factors (except blood pressure). CRP also correlated with plasma levels of the pro‐inflammatory cytokine interleukin 6, and haematocrit, viscosity, red cell aggregation, white cell count, and coagulation factors [fibrinogen, factor (F) VII in women, FVIII, FIX] and inhibitors (antithrombin and protein C in women; protein S) but not coagulation activation markers. CRP was significantly associated with prevalent cardiovascular disease in both men (P = 0·03) and women (P = 0·009), however, the association became non‐significant after adjustment for firstly classical risk factors, then fibrinogen. We conclude that correlations with classical and haematological risk factors account for a substantial component of the association of CRP with prevalent cardiovascular disease, but there is evidence of a residual, independent effect among women.
Use of a cDNA microarray to determine molecular mechanisms involved in grey platelet syndrome
Authors: Hyman Tehila , Huizing Marjan , Blumberg Peter M. , Falik‐Zaccai Tzipora C. , Anikster Yair , Gahl William A.
Published: June 2003

Summary. The grey platelet syndrome (GPS) is a bleeding disorder of unknown aetiology with phenotypic and genetic heterogeneity. Affected patients exhibit macrothrombocytopenia, decreased alpha‐granule content and, sometimes, myelofibrosis. We used microarray technology to investigate changes in gene expression that might reveal mechanisms involved in GPS. The expression of 4900 unique genes and expressed sequence tags was evaluated in fibroblasts from a GPS patient; normal fibroblasts provided the reference standard. Genes that were differentially regulated in the GPS cells were categorized into gene clusters based upon similarity/differences of expression differences. The results showed that genes with functional similarities clustered together. This analysis revealed significant upregulation of selected biological processes involving the production of cytoskeleton proteins, including fibronectin 1, thrombospondins 1 and 2, and collagen VI α. These genes appear to play a role in the pathogenesis of GPS. Indeed, Northern blot analyses confirmed that fibronectin, thrombospondin and matrix metalloprotease‐2 were overexpressed in GPS fibroblasts compared with normal fibroblasts. Moreover, immunohistochemistry studies revealed robust fibronectin staining in GPS fibroblasts compared with normal ones. Our findings support the feasibility of using cDNA microarray techniques to detect distinctive and informative differences in gene expression patterns relevant to GPS, and suggest that the molecular basis for myelofibrosis in GPS involves upregulation of cytoskeleton proteins.
Teaching an engine‐driven preparation technique to undergraduates: initial observations
Authors: Hänni S. , Schönenberger K. , Peters O. A. , Barbakow F.
Published: June 2003

Aim  This paper describes the initial experiences following the introduction of a rotary engine‐driven preparation technique into the undergraduate endodontic programme at the Zurich University Dental Centre.

Methods  Forty third‐year students practised the ProFile .04 (PF .04) technique between January and July 2001 in a preclinical course. Between November 2001 and February 2002, 20 of these students (Group A) root‐treated 51 teeth in their clinical course using either PF .04, the balanced force technique (BFT) or a combination of both. The second group of 20 students (Group B) similarly treated another 36 randomly selected teeth between April and July 2002. Types of teeth treated by the students and the canal preparation techniques were recorded. The students also completed a short questionnaire, evaluating their opinions of the new course.

Results  Of the 87 teeth endodontically treated during the clinical course, 34, 14 and 39 were shaped using PF .04 alone, a combination of PF .04 and BFT and BFT alone, respectively. No rotary instruments were fractured during the 1‐year clinical course, although some instruments were fractured during the preclinical laboratory course. Overall, the students rated the rotary technique as positive.

Conclusion  A rotary technique was successfully introduced into an undergraduate endodontic programme (this will be continued in the foreseeable future). However, the continuity between the preclinical and the clinical courses was poor as a result of the constraints of the general teaching programme.
Epidemiology and Blood Flow Surveillance of the Native Arteriovenous Fistula: A Review of the Recent Literature
Authors: Polkinghorne K. R. , Kerr P. G.
Published: June 2003

Vascular access placement is a key management issue for hemodialysis patients. Despite being well regarded as the access of first choice, the native arteriovenous fistula (AVF) remains underutilized in the United States. The first part of this review examines recent epidemiology studies addressing patient factors associated with the use of the synthetic arteriovenous graft as opposed to the native fistula. Female gender and older age are consistently associated with a higher frequency of graft use. Diabetes, peripheral vascular disease, and body mass index were associated with graft use in some but not all of the studies. Recent evidence also suggests an independent survival advantage for patients dialyzing via native fistulae especially for infection‐related mortality. The second part reviews evidence surrounding the recommendations for blood flow surveillance of the native fistula. The hemodynamic features of the native fistula are examined and differences from synthetic grafts are highlighted. Clinical studies assessing the use of blood flow surveillance to prevent the sudden thrombosis of native fistulae are reviewed. Blood flow thresholds for further investigation are yet to be determined definitely for AVF and randomized studies should be performed to assesses the impact on AVF thrombosis rates.
Twelve‐week RBC storage
Authors: Hess John R. , Hill Heather R. , Oliver Cindy K. , Lippert Lloyd E. , Rugg Neeta , Joines Amy D. , Gormas Jennifer F. , Pratt P. Gayle , Silverstein Edward B. , Greenwalt Tibor J.
Published: June 2003

BACKGROUND: Better storage can improve RBC availability and safety. Optimizing RBC ATP production and minimizing hemolysis has allowed progressively longer storage.

STUDY DESIGN AND METHODS: In the first study, 24 units of packed CPD RBCs were pooled in groups of four, realiquoted, and added to 300 mL of one of four variants of experimental additive solution 76 (EAS‐76) containing 45, 40, 35, or 30 mEq per L NaCl. Units were sampled weekly for 12 weeks for morphologic and biochemical measures. In the second study, 10 volunteers donated 2 units of RBCs for a crossover comparison of Tc/Cr 24‐hour in vivo recovery of 6‐week storage in AS‐1 versus 12‐week storage in EAS‐76 variant 6 (EAS‐76v6) having 30 mEq per L NaCl.

RESULTS: RBCs stored in the lower salt variants of EAS‐76 had higher concentrations of RBC ATP with less hemolysis and microvesiculation. RBC 2,3 DPG was preserved for two weeks. RBCs stored for 12 weeks in EAS‐76v6 exhibited 78 ± 4 percent 24‐hour in vivo recovery.

CONCLUSIONS: It is possible to store RBCs for 12 weeks with acceptable recovery and 0.6 percent hemolysis and with normal 2,3 DPG concentrations for 2 weeks.
Detection of a healthy carrier of HCV with no evidence of antibodies for over four years
Authors: Arrojo Isidro Prat , Pareja Macarena Ortiz , Orta Maria Dolores Retamero , Luque Federico Navajas , Lamas Maria Carmen Hernandez , Gordo Hrancisco Sanchez , Mancha Isabel Vidales
Published: June 2003

BACKGROUND: Posttransfusion HCV has been notably reduced over recent years as a result of the systematic testing for antibodies to HCV in blood donors. However, the risk of transfusing blood‐derived components from virus‐carrying donors still remains. A diagnosis is reported here of HCV in a regular blood donor who had no antibodies during the entire time she was followed up.

CASE REPORT: The pharmaceutical company responsible for fractioning the plasma detected a donor who was a carrier of HCV, confirmed by PCR, but whose tests to detect anti‐HCV were systematically negative. The donor had given blood on five previous occasions, from which 14 components were manufactured. Of the 11 components traced, six had been transfused, and in the two cases in which study of the anti‐HCV was possible in the recipients, the result was positive. It was possible to check the blood samples from the donor from May 1997 to March 2002 (58 months). The tests to detect anti‐HCV were all negative, while the PCR and core antigen tests were positive.

CONCLUSION: The incorporation of RNA detection or HCV core antigen techniques in blood banks may reduce the residual risk of contracting posttransfusion HCV. Measures such as the correct traceability of the components, the existence of a specimen bank, or follow up of the recipients of blood‐derived components would help to improve the quality of blood banking with percentage of survivability and case investigations.
Electromagnetic fields and human body: a new challenge for the electromagnetic field computation
Authors: Siauve N. , Scorretti R. , Burais N. , Nicolas L. , Nicolas A.
Published: June 2003

The electromagnetic fields have a great influence on the behaviour of all the living systems. The as low as reasonably achievable (ALARA) principle imposes, in case of long exposures to low (i.e. power systems) or high frequency (i.e. microwave systems or cell phones) fields, some limitations to the radiated fields by the industrial equipment. On the other hand, some benefits can be taken from the effects of the electromagnetic fields on the living being: the hyperthermal technique is well known for the treatment of the cancer. Either we want to be protected from the fields, or we want to take benefit of the positive effects of these fields, all the effects thermal as well as genetic have to be well known. Like in any industrial application, the electromagnetic field computation allows a better knowledge of the phenomena, and an optimised design. Hence, there is a very important challenge for the techniques of computation of electromagnetic fields. The major difficulties that appear are: (1) related to the material properties – the “material” (the human body) has very unusual properties (magnetic permeability, electric permittivity, electric conductivity), these properties are not well known and depend on the activity of the person, and this material is an active material at the cell scale; (2) related to the coupling phenomena – the problem is actually a coupled problem: the thermal effect is one of the major effects and it is affected by the blood circulation; (3) related to the geometry – the geometry is complex and one has to take into account the environment. The problems that we have to face with are – the identification of the properties of the “material”, the coupled problem solution and the representation of the simulated phenomena.
Optics with Quantum Hall Skyrmions
Authors: Portengen T. , Chapman J. R. , Nicopoulos V. Nikos , Johnson N. F.
Published: June 2003

A novel type of charged excitation, known as a Skyrmion, has recently been discovered in quantum Hall systems with filling factor near ν=1. A Skyrmion — which can be thought of as a topological twist in the spin density of the electron gas — has the same charge as an electron, but a much larger spin. In this review we present a detailed theoretical investigation of the optical properties of Skyrmions. Our results provide means for the optical detection of Skyrmions using photoluminescence (PL) spectroscopy. We first consider the optical properties of Skyrmions in disordered systems. A calculation of the luminescence energy reveals a special optical signature which allows us to distinguish between Skyrmions and ordinary electrons. Two experiments to measure the optical signature are proposed. We then turn to the optical properties of Skyrmions in pure systems. We show that, just like an ordinary electron, a Skyrmion may bind with a hole to form a Skyrmionic exciton. The Skyrmionic exciton can have a lower energy than the ordinary magnetoexciton. The optical signature of Skyrmions is found to be a robust feature of the PL spectrum in both disordered and pure systems.
The Hierarchy of Fractional Quantum Hall States and Berry Phase
Authors: Basu B. , Bandyopadhyay P.
Published: June 2003

The Hierarchy of Fractional Quantum Hall (FQH) states have been studied here in the framework of chiral anomaly and Berry Phase. It is shown that the unambiguously observed FQH states with filling factor ν=p/q with p even or odd and q an odd integer can be considered from the viewpoint that the Berry phase associated with even number of vortices can be removed to the dynamical phase and the corresponding fermionic state attains a higher Landau level. This also leads to the fact that FQH states with even denominator filling factor can arise when we have pairs of degenerate electrons giving rise to the non-Abelian Berry phase which suggests that these FQH states correspond to non-Abelian Hall fluid. In this framework Integer Quantum Hall Effect (IQHE) as well as Fractional Quantum Hall Effect (FQHE) with filling factor ν=p/q with q odd or even can be studied in a unified way.
Complex Behavior in Earthquake Dynamics
Authors: Nakanishi Hiizu
Published: June 2003

Recent progresses in understanding earthquake dynamics with the aid of a simple spring-block system is reviewed from a physicists' point of view. Dynamical instability due to negative dynamical friction amplifies any perturbation and leads to a chaotic behavior for almost any initial configurations. It is also pointed out that static friction gives another source of the complex behavior which is characteristic to a threshold element system.
Pattern Formation by Inelastic Collisions, Especially in Planetary Systems
Authors: Kawai Toshio
Published: June 2003

The Titius–Bode law governs the planet distribution in our Solar system. In this paper a possible explanation is proposed based on inelastic collision effects among planetessimals during the evolution of the Solar system. The main purpose of this paper is, however, to introduce a strategy to study phenomena driven by rare but drastic events such as colllisions in the planetary problem. Many complex systems evolve through rare but violent events, so that an efficient strategy to simulate such systems is desirable. An event-driven strategy is proposed in this article, and is used to produce many runs of 108 year evolution history of planetary systems. I have found that the Titius–Bode law holds approximately, if the gravitational effect (scattering) and the collisions are taken into account. The result illustrates the importance of inelastic collisions, which are often neglected in the standard classical mechanics courses. Therefore, for completeness, other simpler particle systems under the effect of inelastc collisions, such as one-dimensional systems, are also included.
Electrical Generation of Spontaneous Optical Emission in Electrically Modulated Two-Dimensional Electron Gases at Low-Temperatures
Authors: Xu W. , Zhang C.
Published: June 2003

A detailed theoretical study is presented for spontaneous optical emission from a two-dimensional electron gas (2DEG) in the presence of a unidirectional spatially periodic modulation at low temperatures. The momentum- and energy-balance equations for electron–photon interactions in the device system are solved self-consistently using the Boltzmann equation, from which we can obtain the frequency and the intensity of the electromagnetic radiation generated. The results obtained indicate that: (1) in an electrically modulated 2DEG at low temperatures, a strong electromagnetic radiation emission up to W/cm2 can be generated by applying a small d.c. electric field; (2) the radiation emission is generated indirectly in the occupied subbands through electronic transitions around the Fermi level; (3) the frequency of the radiation generated is at about 0.1 THz; (4) in the low frequency regime, spontaneous multiphoton emissions can be observed; and (5) this type of optical emission depends strongly on the sample parameters such as the electron density of the 2DEG and the modulation length.
Aspects of a Single Vortex in d-Wave Superconductors
Authors: Morita Y. , Kohmoto M. , Maki K.
Published: June 2003

Physical properties of a single vortex in d-wave superconductors are studied theoretically. After a brief review on a single vortex in "conventional" s-wave superconductors and the d-wave superconductivity underlying the hole-doped high-T c cuprates, we go on to study the quasiparticle spectrum around a single vortex in the high-T c superconductors. One of the characteristics of the high-T c superconductors is that they are close to the "quantum limit" (pFξ ~ O(1)). A new picture emerges of the quasiparticle spectrum. Instead of thousands of bound states in a "conventional" s-wave superconductor, we find only a few peaks in the local density of states at the vortex center. Further there are low-lying excitations stretched in four diagonal directions and they have no counterpart in s-wave superconductors.
Fractional Quantum Hall Effect States as Exact Ground States
Authors: Ghosh Ranjan Kumar , Rao Sumathi
Published: June 2003

We construct many particle Hamiltonians for which the Laughlin and Jain wavefunctions are exact ground states. The Hamiltonians involve fermions in a magnetic field and with inter-particle interactions. For the Laughlin wave-functions, the interactions involve two- and three-body correlations similar to the Chern–Simons interactions, whereas for the projected Jain wave-functions, N-body interactions (which cannot be explicitly written down in general) are involved.
Two-Loop RG Calculation of Sound Attenuation and Dispersion Near the Liquid-Gas Critical Point
Authors: Adzhemyan L. Ts. , Vasiljev A. N. , Serdukov A. V.
Published: June 2003

We calculate the singular part of the sound attenuation and dispersion near the liquid-gas critical point on the critical isochore above T c . It is shown that the corresponding scaling function is related to the correlation function <ψ2ψ2> of two composite operators of the Halperin-Hohenberg–Siggia model H.1 Using the renormalization group (RG) and ∊-expansion we obtain this scaling function in second order in ∊.
Renormalization Theory for Ordered Phase of 2D XY Magnet with Dipolar Interaction
Authors: Kashuba Alexander
Published: June 2003

In the ordered phase of 2D XY ferromagnet the dipolar interaction between spins induces a relevant interaction between spin-waves. Although the density of spin-waves is small at low temperature, this long-range interaction correlates two spatially separated spin-waves. Anomalous scaling of spin-wave correlation functions is found in both statics and dynamics cases.
The Lowest Diploid Number (2n = 16) yet Found in Any Primate: Callicebus lugens (Humboldt, 1811)
Authors: Bonvicino Cibele R. , Penna-Firme Valéria , do Nascimento Fabrícia F. , Lemos Bernardo , Stanyon Roscoe , Seuánez Héctor N.
Published: June 2003

Morphologic, molecular and karyologic analyses of Callicebus lugens (Humboldt, 1811) of known geographic origin supported the proposition that this is a valid species. Morphologic and morphometric analyses showed evident differences between C. lugens and two other related taxa of the same group (Callicebus purinus and Callicebus torquatus). Cytochrome b DNA analyses (maximum parsimony, neighbour joining and maximum likelihood) were congruent in showing a strong association between C. lugens and Callicebus sp. of the torquatus group in one branch and a sister branch further divided into two clades: one with species of the personatus group and another, with species of the moloch group. Karyotypic analysis showed that C. lugens has the lowest diploid chromosome number of the primate order (2n = 16). Comparisons with other congeneric species clearly supported the proposition that C. lugens is karyotypically similar to others of the torquatus group.
Nerve Growth Factor: Neurotrophin or Cytokine?
Authors: Bonini S. , Rasi G. , Bracci-Laudiero M.L. , Procoli A. , Aloe L.
Published: June 2003

Nerve growth factor (NGF) is a neutrophin exerting an important role in the development and functions of the central and peripheral nervous system. However, it has recently been documented that several immune cells – such as mast cells, lymphocytes and eosinophils – produce, store and release NGF. Moreover, NGF high and low affinity receptors are widely expressed in the immune system, thus indicating the potential of responding to this neurotrophin through an autocrine mechanism. In fact, NGF influences development differentiation, chemotaxis and mediator release of inflammatory cells as well as fibroblast activation through a complex network influenced by other pro-inflammatory cytokines. Finally, NGF is increased in biological fluids of several allergic, immune and inflammatory diseases. Data reviewed suggest, therefore, that NGF might also be viewed as a (Th2?) cytokine with a modulatory role in allergic inflammation and tissue remodeling.
Cancer Cell Biology: A Student-Centered Instructional Module Exploring the Use of Multimedia to Enrich Interactive, Constructivist Learning of Science
Authors: Bockholt Susanne M. , West J. Paige , Bollenbacher Walter E.
Published: June 2003

Multimedia has the potential of providing bioscience education novel learning environments and pedagogy applications to foster student interest, involve students in the research process, advance critical thinking/problem-solving skills, and develop conceptual understanding of biological topics. Cancer Cell Biology, an interactive, multimedia, problem-based module, focuses on how mutations in protooncogenes and tumor suppressor genes can lead to uncontrolled cell proliferation by engaging students as research scientists/physicians with the task of diagnosing the molecular basis of tumor growth for a group of patients. The process of constructing the module, which was guided by scientist and student feedback/responses, is described. The completed module and insights gained from its development are presented as a potential “multimedia pedagogy” for the development of other multimedia science learning environments.
A learning approximator for compact representation of experimental mappings
Authors: Carotenuto Riccardo
Published: June 2003

An iterative technique is proposed to efficiently represent n‐dimensional discrete mappings from experimental sampled data. The original sampled mapping is approximated, under some assumptions, with a proper set of one‐dimensional arrays. The proposed technique highly reduces the severe memory requirements of classical memory‐based techniques. A convergence discussion on the proposed algorithm and application examples are presented. Copyright © 2003 John Wiley & Sons, Ltd.
Preparation and adsorption properties of the chelating resins containing carboxylic, sulfonic, and imidazole groups
Authors: Rivas Bernabé L. , Jara Miguel , Pereira Eduardo D.
Published: June 2003

The crosslinked poly(1‐vinylimidazole‐co‐acrylic acid), P(VIm‐co‐AA), and poly(1‐vinylimidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) P(VIm‐co‐APSA) were synthesized by radical polymerization and tested as adsorbents under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) by batch equilibrium procedure. The resin–metal ion equilibrium was achieved before 1 h. The resin P(VIm‐co‐AA) showed a maximum retention capacity (MRC) value for Pb(II) at pH 3 and Hg(II) at pH 1 of 1.1 and 1.2 mEq/g, respectively, and the resin P(VIm‐co‐AA) showed at pH 3 the following MRC values: Hg(II) (1.5 mEq/g), Cd(II) (1.9 mEq/g), Zn(II) (2.7 mEq/g), and Cr(III) (2.8 mEq/g). The recovery of the resin was investigated at 25°C with 1 M and 4 M HNO3 and 1 M and 4 M HClO4. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2852–2856, 2003
The efficacy of complement‐mediated phagocytosis of Cryptococcus neoformans is dependent on the location of C3 in the polysaccharide capsule and involves both direct and indirectC3‐mediated interactions
Authors: Zaragoza Oscar , Taborda Carlos P. , Casadevall Arturo
Published: June 2003

Complement component 3 (C3) is the major opsonin for the pathogenic fungus Cryptococcus neoformans in the non‐immune host. However, the efficiency of complement‐mediated opsonization varies, depending on the strain, through mechanisms that are not understood. Analysis of complement‐mediated phagocytosis for 12 strains grown in Sabouraud medium revealed that phagocytic indices were inversely correlated with capsule volume. In contrast, there was no correlation between phagocytic index and capsule volume for IgG1‐opsonized cells. When capsule size was increased, the efficacyof complement‐mediated phagocytosis decreased, whereas that of antibody‐mediated phagocytosis increased. C3 localized inside the capsule and at the outer capsule edge for poorly phagocytozed and well‐phagocytozed strains, respectively. Blocking experiments revealed that complement‐mediated phagocytosis occurred through complement receptor 3 (CR3), without significant involvement of CR1 or CR4. Blocking experiments with antibodies to C3 did not completely abrogate yeast cell uptake, consistent with phagocytosis through glucuronoxylomannan–CR3 interactions. Our data explain how some large encapsulated cells avoid phagocytosis and suggest a novel strategy for immune evasion whereby a microbial capsule interferes with phagocytosis by modifying the location of C3 deposition.
Logical inconsistencies in survey respondents' health state valuations ‐ a methodological challenge for estimating social tariffs
Authors: Devlin Nancy J. , Hansen Paul , Kind Paul , Williams Alan
Published: June 2003

Logical inconsistencies in survey respondents' valuations of hypothetical health states – represented by the EQ‐5D, for example – present a conundrum as to whether or not their responses ought to be included for estimating social ‘tariffs’. A ‘logical inconsistency’ occurs when a state that ‘in logical terms’ is unambiguously less severe than another is assigned a lower value. Excluding such responses is defensible on data quality grounds but puts at risk the representativeness of the estimated tariff, given it is meant to represent the preferences of ‘society’. This paper explores the rationale for and effect of excluding, to varying degrees, responses distinguished by the number of pairwise inconsistencies they contain, and reports equations for two tariffs that arise from contrasting approaches. The data are from a random sample of adult New Zealanders whose visual analogue scale valuations for a selection of EQ‐5D states were collected in 1999 via a postal survey to which 1360 people responded (a 50% response rate). We conclude that there is no simple, generalisable ‘rule’ to guide exclusions and therefore researchers ought to explore the sensitivity of their estimated tariffs (and ultimately QALY estimates) to alternative treatments of logically inconsistent responses. Copyright © 2002 John Wiley & Sons, Ltd.