bluuebunny/crossref_metadata_2025_split huggingface dataset:
Femoral derotation osteotomy in spastic diplegia
Authors: Pirpiris M. , Trivett A. , Baker R. , Rodda J. , Nattrass G. R. , Graham H. K. 
Published: March 2003

We describe the results of a prospective study of 28 children with spastic diplegia and in-toed gait, who had bilateral femoral derotation osteotomies undertaken at either the proximal intertrochanteric or the distal supracondylar level of the femur. Preoperative clinical evaluation and three-dimensional movement analysis determined any additional soft-tissue surgery. Distal osteotomy was faster with significantly lower blood loss than proximal osteotomy. The children in the distal group achieved independent walking earlier than those in the proximal group (6.9 ± 1.3 v 10.7 ± 1.7 weeks; p < 0.001). Transverse plane kinematics demonstrated clinically significant improvements in rotation of the hip and the foot progression angle in both groups. Correction of rotation of the hip was from 17 ± 11° internal to 3 ± 9.5° external in the proximal group and from 9 ± 14° internal to 4 ± 12.4° external in the distal group. Correction of the foot progression angle was from a mean of 10.0 ± 17.3° internal to 13.0 ± 11.8° external in the proximal group (p < 0.001) compared with a mean of 7.0 ± 19.4° internal to 10.0 ± 12.2° external in the distal group (p < 0.001). Femoral derotation osteotomy at both levels gives comparable excellent correction of rotation of the hip and foot progression angles in children with spastic diplegia.
The use of a closed-suction drain in total knee arthroplasty
Authors: Esler C. N. A. , Blakeway C. , Fiddian N. J. 
Published: March 2003

We prospectively randomised 100 patients undergoing cemented total knee replacement to receive either a single deep closed-suction drain or no drain. The total blood loss was significantly greater in those with a drain (568 ml versus 119 ml, p < 0.01; 95% CI 360 to 520) although those without lost more blood into the dressings (55 ml versus 119 ml, p < 0.01; 95% CI −70 to 10). There was no statistical difference in the postoperative swelling or pain score, or in the incidence of pyrexia, ecchymosis, time at which flexion was regained or the need for manipulation, or in the incidence of infection at a minimum of five years after surgery in the two groups. We have been unable to provide evidence to support the use of a closed-suction drain in cemented knee arthroplasty. It merely interferes with mobilisation and complicates nursing. Reinfusion drains may, however, prove to be beneficial.
The effect of knee flexion on the popliteal artery and its surgical significance
Authors: Shetty A. A. , Tindall A. J. , Qureshi F. , Divekar M. , Fernando K. W. K. 
Published: March 2003

Total knee replacement and high tibial osteotomy are common orthopaedic operations with low complication rates. Such surgery is in close proximity to the popliteal artery (PA), the behaviour of which during flexion of the knee is poorly understood. We used Duplex ultrasonography to determine the distance of the PA from the posterior tibial surface at 0° and 90° of flexion in 100 knees. When the knee was flexed the PA was closer to the posterior tibial surface at 1 to 1.5 cm below the joint line in 24% and at 1.5 to 2 cm below the joint line in 15%. There was a high branching anterior tibal artery in 6% of knees. We provide an anatomical account to help to explain our findings by using cadaver dissections, arteriography and static MRI studies.
Effect of smoking on early complications after elective orthopaedic surgery
Authors: Møller A. M. , Pedersen T. , Villebro N. , Munksgaard A. 
Published: March 2003

Smoking is an important risk factor for the development of postoperative pulmonary complications after major surgical procedures. We studied 811 consecutive patients who had undergone hip or knee arthroplasty, recording current smoking and drinking habits, any history of chronic disease and such intraoperative factors as the type of anaesthesia and the type and duration of surgery. We recorded any postoperative complications occurring before discharge from hospital. There were 232 smokers (28.6%) and 579 non-smokers. We found that smoking was the single most important risk factor for the development of postoperative complications, particularly those relating to wound healing, cardiopulmonary complications, and the requirement of postoperative intensive care. A delay in discharge from hospital was usual for those suffering a complication. In those patients requiring prolonged hospitalisation (> 15 days) the proportion of smokers with wound complications was twice that of non-smokers.
Noncovalent Binding of a Reaction Intermediate by a Designed Helix‐Loop‐Helix Motif—Implications for Catalyst Design
Authors: Allert Malin , Baltzer Lars 
Published: March 2003

AbstractIn our search for a catalyst for the transamination reaction of aspartic acid to form oxaloacetate, twenty‐five forty‐two‐residue sequences were designed to fold into helix‐loop‐helix dimers and form binding sites for the key intermediate along the reaction pathway, the aldimine. This intermediate is formed from aspartic acid and the cofactor pyridoxal phosphate. The design of the binding sites followed a strategy in which exclusively noncovalent forces were used for binding the aldimine. Histidine residues were incorporated to catalyse the rate‐limiting 1,3 proton transfer reaction that converts the aldimine into the ketimine, an intermediate that is subsequently hydrolysed to form oxaloacetate and pyridoxamine phosphate. The two most efficient catalysts, T‐4 and T‐16, selected from the pool of sequences by a simple screening procedure, were shown by CD and NMR spectroscopies to bind the aldimine intermediate with dissociation constants in the millimolar range. The mean residue ellipticity of T‐4 in aqueous solution at pH 7.4 and a concentration of 0.75 mM was −18 500 deg cm2 dmol−1. Upon addition of 6 mm l‐aspartic acid and 1.5 mM pyridoxal phosphate to form the aldimine, the mean residue ellipticity changed to −19 900 deg cm2 dmol−1. The corresponding mean residue ellipticities of T‐16 were −21 200 deg cm2 dmol−1 and −24 000 deg cm2 dmol−1. These results show that the helical content increased in the presence of the aldimine, and that the folded polypeptides bound the aldimine. The 1H NMR relaxation time of the imine CH proton of the aldimine was affected by the presence of T‐4 as was the 31P NMR resonance linewidth. The catalytic efficiencies of T‐4 and T‐16 were compared to that of imidazole and found to be more than three orders of magnitude larger. The designed binding sites were thus shown to be capable of binding the aldimine in close proximity to His residues, by noncovalent forces, into conformations that proved to be catalytically active. The results show for the first time the design of well‐defined catalytic sites that bind a reaction intermediate with enzyme‐like affinities under equilibrium conditions and represent an important advance in de novo catalyst design.
Are financial markets efficient? Phase transition in the aggregation of information
Authors: Berg Johannes , Marsili Matteo , Rustichini Aldo , Zecchina Riccardo 
Published: March 2003

AbstractFinancial markets can be considered as collective information processing devices, which aggregate the information on relevant events into market prices. We show that, in a simple model, markets are efficient aggregators of information only if the number of traders is sufficiently large compared to the number of relevant events. The transition to an efficient market occurs through a phase transition, well known from critical phenomena in physics. © 2003 Wiley Periodicals, Inc.
Dynamics of social networks
Authors: Ebel Holger , Davidsen Jörn , Bornholdt Stefan 
Published: March 2003

AbstractComplex networks such as the World Wide Web, the web of human sexual contacts, or criminal networks often do not have an engineered architecture but instead are self‐organized by the actions of a large number of individuals. From these local interactions nontrivial global phenomena can emerge as small‐world properties or scale‐free degree distributions. A simple model for the evolution of acquaintance networks highlights the essential dynamical ingredients necessary to obtain such complex network structures. The model generates highly clustered networks with small average path lengths and scale‐free as well as exponential degree distributions. It compares well with experimental data of social networks, as for example, coauthorship networks in high energy physics. © 2003 Wiley Periodicals, Inc.
Viral evolution under the pressure of an adaptive immune system: Optimal mutation rates for viral escape
Authors: Kamp Christel , Wilke Claus O. , Adami Christoph , Bornholdt Stefan 
Published: March 2003

AbstractBased on a recent model of evolving viruses competing with an adapting immune system (Kamp and Bornholdt, Co‐evolution of quasispecies: B‐cell mutation rates maximize viral error catastrophes. Phys Rev Lett 88, 2002), we study the conditions under which a viral quasispecies can maximize its growth rate. We find that a virus is most viable if it generates on average precisely one mutation within the time it takes for the immune system to adapt to a new viral epitope. Experimental viral mutation rates, in particular for HIV (human immunodeficiency virus), seem to suggest that many viruses have achieved their optimal mutation rate. © 2003 Wiley Periodicals, Inc.
Stochastic modeling of fat‐tailed probabilities of foreign exchange rates
Authors: Karth Mathias , Peinke Joachim 
Published: March 2003

AbstractIn a recent work (Renner, C; Peinke, J.; Friedrich, R. Physica A 2001, 298, 211–217) it has been shown that the statistics of price changes on foreign‐exchange rates measured by increments can be characterized completely by a Fokker‐Planck equation. The explicit form of this Fokker‐Planck equation was deduced directly from empirical data. Here we show that this result does not hold only for one specific construction of price changes by increments but also for returns and logarithmic returns, which are commonly used to quantify fluctuations in financial time‐series over different time horizons. For all these quantities (increment and both kinds of returns) an explicit Fokker‐Planck equation is presented and a verification of the quality of this description is shown by the reproduction of fat‐tailed probability density functions for different time scales. We propose this method as a generalization of multifractal analysis. © 2003 Wiley Periodicals, Inc.
Adaptation and metalevels in a competitive game
Authors: Schuster Heinz Georg 
Published: March 2003

AbstractWe investigate a competitive game between two players where the player who correctly guesses the output of the other will win. By modeling the players with adaptive Booleans we show that a growing number of inputs to the Booleans provides the players with a metalevel view of the game which enables them to model their and their opponent's behavior by adaptation. Thereby the players will take turns in winning game, according to their degree of complexity. © 2003 Wiley Periodicals, Inc.
Sequence complexity in Darwinian evolution
Authors: Adami Christoph 
Published: March 2003

AbstractWhether or not Darwinian evolution leads to an increase in complexity depends crucially on what we mean by the term. Physical complexity is a measure based on automata theory and information theory that turns out to be a simple and intuitive measure of the amount of information that an organism stores, in its genome, about the environment in which it evolves. It can be shown that the physical complexity of the genomes of clonal organisms must increase in evolution, if they occupy a single niche and if the environment does not change. This law of increasing complexity is a consequence of natural selection only and can be violated in co‐evolving systems as well as at high mutation rates, in sexual populations, and in time‐dependent landscapes. Yet, co‐evolution, because it can be viewed as creating an increase in physical complexity across niches, is likely the agent of a global increase in complexity. © 2003 Wiley Periodicals, Inc.
Optimization with extremal dynamics
Authors: Boettcher Stefan , Percus Allon G. 
Published: March 2003

AbstractA local‐search heuristic for finding high‐quality solutions for many hard optimization problems is explored. The method is inspired by recent progress in understanding far‐from‐equilibrium phenomena in terms of self‐organized criticality, a concept introduced to describe emergent complexity in physical systems. This method, called extremal optimization, successively replaces the value of extremely undesirable variables in a sub‐optimal solution with new, random ones. Large, avalanche‐like fluctuations in the cost function emerge dynamically. These enable the search to effectively scaling barriers to explore local optima in distant neighborhoods of the configuration space while eliminating the need to tune parameters. Drawing upon models used to simulate the dynamics of granular media, evolution, or geology, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. This method is very general and so far has proved competitive with—and even superior to—more elaborate general‐purpose heuristics on testbeds of constrained optimization problems with up to 105 variables, such as bipartitioning, coloring, and spin glasses. Analysis of a model problem predicts the only free parameter of the method in accordance with all experimental results. © 2003 Wiley Periodicals, Inc.
Diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes: A study of 210 cases
Authors: Gupta Raj K. , Naran Sarla , Lallu Sharda , Fauck Robert 
Published: March 2003

AbstractThe aim of this study was to evaluate the diagnostic value of needle aspiration cytology (NAC) in the assessment of palpable inguinal lymph nodes, which were analyzed in 210 cases. NAC in all the cases were performed by the conventional aspiration method and cytologic examination was done on site after staining smears with the Papanicolaou method. In addition, Diff‐Quik‐stained air‐dried smears, Papanicolaou‐stained fixed smears, and filter preparations from needle washings and hematoxylin‐eosin‐stained sections of cell blocks were studied. The NAC diagnosis was supported by examining cell blocks in 92/210 cases which showed a reliable histologic architecture; further support was also obtained with a tissue biopsy in 9/12 cases of inflammatory lesions, 7/7 cases with a suspicious diagnosis, 20/26 cases of melanomas, 15/15 cases of lymphomas, and/or a comparison with the primary tumor in other cases of metastatic tumors. Additionally, immunoperoxidase and/or histochemical stains were done. Twelve cases were diagnosed as inflammatory lesions and 88 cases were regarded as negative (normal cellular elements n = 40; reactive elements n = 48). In 58 cases a variety of metastatic tumors were diagnosed (melanoma n = 26; others n = 32) and in 15 cases a diagnosis of lymphoma was made. Seven cases were diagnosed as suspicious of malignancy and 30 cases were unsatisfactory due to scanty/acellular samples (despite 2–3 repeat samplings). However, in five of these malignant tumors were later found on a biopsy which was done due to a persistent and continued enlargement of lymph node(s). The sensitivity was 91.7%, specificity 98.2%, positive predictive value (PPV) 97.7.%, and negative predictive value (NPV) was 95.45%. Based on our study we feel that NAC as a first line of investigation is not only useful in the diagnosis of lesions in inguinal lymph nodes, but can also help in deciding on an appropriate management. Also, histologic architecture from cell blocks can be correlated with cytology and such material can be used for histochemical and immunomarker studies. Diagn. Cytopathol. 2003;28:175–180. © 2003 Wiley‐Liss, Inc.
Cytologic diagnosis of low‐grade papillary urothelial neoplasms (low malignant potential and low‐grade carcinoma) in the context of the 1998 WHO/ISUP classification
Authors: Whisnant Richard E. , Bastacky Sheldon I. , Ohori N. Paul 
Published: March 2003

AbstractThe 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification of urothelial neoplasms introduced a category called papillary neoplasm of low malignant potential (LMP) and separated it from low‐grade papillary urothelial carcinoma (LGPUC), which was thought to yield abnormal cells in cytology specimens. The objective of our study was to evaluate the effectiveness of urine cytology in diagnosing these lesions. Eighty‐six paired transurethral surgical biopsy and corresponding urine cytology specimens representing the spectrum of urothelial papillary lesions were examined. Consensus diagnosis on each biopsy was made, and the distribution was as follows: 16 benign urothelium, 27 LMP, 28 LGPUC, and 15 high‐grade papillary urothelial carcinoma (HGPUC). This was followed by a blinded independent review of the urine cytology specimens by three observers. Each cytology case was marked as negative, atypical, suspicious, or positive for malignant cells by using previously published cytologic criteria. When the negative and atypical diagnoses were grouped together as “benign” and the suspicious and malignant diagnoses as “malignant,” the detection rate of “malignancy” of the lesions was as follows: LMP, 37%; LGPUC, 25%; and HGPUC, 53%. The false positive rate was 6%, and the positive predictive value (PPV) was 94%. Detection rates of cells that were at least “atypical” were as follows: LMP, 74%; LGPUC, 79%; and HGPUC, 100%. While most of the LMP and LGPUC cases yielded cells that were at least “atypical,” there was no significant difference in the distribution of cytologic diagnoses for LMP and LGPUC cases (P > 0.05). Urine cytology in the context of the 1998 WHO/ISUP classification appears to be useful as a screening tool but does not appear to discriminate LMP effectively from LGPUC. Diagn. Cytopathol. 2003;28:186–190. © 2003 Wiley‐Liss, Inc.
Cytodiagnosis of primary lymphoma of bone on fine‐needle aspiration cytology specimens: Review of 25 cases
Authors: Lin Fan , Staerkel Gregg , Fanning Tina V. 
Published: March 2003

AbstractDiagnosis of nodal lymphomas on fine‐needle aspiration (FNA) cytologic specimens has been well established. However, cytodiagnosis of primary lymphoma of bone has not been well documented because of its rarity. We undertook a retrospective study of 25 cases of FNA cytologic specimens of primary lymphoma of bone. The slides were available for review in 20 cases; each case was evaluated with 15 cytologic features in conjunction with immunophenotyping and available surgical materials. Three diagnostic categories were assigned, including nondiagnostic (4/16%), suspicious (3/12%), and malignant (18/72%). Among the 18 malignant lymphoma, all were diagnosed on the basis of cytologic materials together with immunocytochemistry, except that two cases also relied on the cell blocks. The nondiagnostic and suspicious cases were subsequently confirmed to be malignant lymphoma on the surgical core biopsies. Of the 25 cases, 23 cases were large B‐cell lymphoma, one follicular lymphoma large cell type, and one small lymphocytic lymphoma. False‐positive or false‐negative cases were not present in this study series. In conclusion, the vast majority of primary lymphoma of bone can be accurately diagnosed and classified on FNA cytologic specimens in conjunction with immunocytochemistry. The nondiagnostic and suspicious categories can be further reduced or eliminated by improving FNA techniques or by recommendation of surgical core biopsies together with other techniques such as flow cytometry and molecular analysis. Diagn. Cytopathol. 2003;28:205–211. © 2003 Wiley‐Liss, Inc.
Nested reciprocities: The organism–environment system in perception–action and development
Authors: Wagman Jeffrey B. , Miller David B. 
Published: March 2003

AbstractThe ecological approach to studying perception and action is one in which researchers view the structure in ambient energy arrays surrounding a given organism as being sufficient to specify meaningful environmental properties to that organism. Thus, from this perspective, perception is viewed not as a cognitive achievement but as a lawful state of affairs that exists in an organism–environment system. The approach to studying development known as transactionalism is one in which researchers view the developmental process as the expression of a complex web of endogenous and exogenous factors. Thus, from this perspective, development is not an unfolding of a genetic program, but rather an ongoing exchange among levels of the organism–environment system that continues throughout the life span of the organism. Despite their independent development, these two meta‐theoretical approaches have much in common. In each approach, the organism–environment system is the fundamental unit of analysis, and the development of perception and behavior is spread across the multiple levels of this system. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 317–334, 2003.
Stable operation region and dynamic behavior of Ar pulse‐modulated induction thermal plasma with different molecular gases
Authors: Tanaka Yasunori , Sakuta Tadahiro 
Published: March 2003

AbstractThe pulse‐modulated induction thermal plasma (PMITP) was established in Ar gas with additional gases such as H2, O2, N2, and CO2 to investigate the effects of various gas inclusions on the transient characteristics of thermal plasma. The dynamic response times of the thermal plasmas were estimated from the measured time‐varying radiation intensity of Ar spectral line. Furthermore, time evolution of the Ar excitation temperature was determined by the two‐line method. The results indicated that especially in Ar‐CO2 PMITP, decreasing the current level in a modulation cycle raised the on‐delay time which means a recovery time from a low‐temperature state to a high‐temperature one. In addition, the inclusion of CO2 in Ar PMITP caused lower temperatures just before the on‐operation compared with other gases used in the experiment. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(4): 1–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10144
Structure‐function studies of the C3a‐receptor: C‐terminal serine and threonine residues which influence receptor internalization and signaling
Authors: Settmacher Britta , Rheinheimer Claudia , Hamacher Henning , Ames Robert S. , Wise Alan , Jenkinson Lesley , Bock Daniel , Schaefer Myriam , Köhl Jörg , Klos Andreas 
Published: March 2003

AbstractThe anaphylatoxic peptide C3a is a pro‐inflammatory mediator generated during complement activation, whose specific G protein coupled receptor is expressed on granulocytes, monocytes, mast cells, activated lymphocytes, and in the nervous tissue. We have generated RBL‐2H3 cell clones stably expressing mutants of the human C3a‐receptor (C3aR) with combined alanine (Ala) substitutions of ten C‐terminal serine (Ser) or threonine (Thr) residues, which may represent putative phosphorylation sites to characterize their role in ligand‐induced C3aR internalization and signaling. Ser475/479 and Thr480/481 as well as Ser449 seemed not to be involved in ligand‐induced receptor internalization. Either directly or by a conformational change they even "inhibit" C3aR internalization. In contrast, mutants with Ala substitutions at Ser465/470 and Thr463/466 were poorly internalized, and Thr463 seemed to be the most important C‐terminal Thr or Ser residue directly effecting receptor internalization. However, it is likely that other C3aR regions additionally participate in this negative feed‐back mechanism since even mutants with multiple Ala substitutions still internalized to a limited degree. Interestingly, in a mutant with a single exchange of Ser449 to Ala, the signal transduction assessed by a Ca2+ assay and [35S]GTPγS‐binding on HEK cells transiently co‐transfected with G‐alpha 16 or G‐alpha O, respectively, was severely impaired, indicating that this residue of C3aR is involved in G protein coupling.