bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recombinant Chlorobenzene Dioxygenase from Pseudomonas sp. P51: A Biocatalyst for Regioselective Oxidation of Aromatic Nitriles
Authors: Yildirim Selcuk , Franko Telma T. , Wohlgemuth Roland , Kohler Hans‐Peter E. , Witholt Bernard , Schmid Andreas 
Published: June 2005

AbstractAn efficient biocatalyst was developed for the cis‐dihydroxylation of aromatic nitriles. The chlorobenzene dioxygenase (CDO) genes of Pseudomonas sp. strain P51 were cloned under the strict control of the Palk promoter of Pseudomonas putida GPo1. Escherichia coli JM101 cells carrying the resulting plasmid pTEZ30 were used for the biotransformation of benzonitrile in a 2‐L stirred tank bioreactor. Use of a stable expression system resulted in an average specific activity and an average volumetric productivity of 1.47 U/g cdw and 120 mg of product/h/L, respectively. The values represent a three‐fold increase compared to the results of the similar biotransformations with E. coli JM101 (pTCB144) where the genes of CDO were expressed under the control of lac promoter. The productivity of the cis‐dihydroxylation process was limited by product toxicity. Removal of the products at toxic concentrations by means of an external charcoal column resulted in an additional increase in product concentration by 43%. E. coli JM101 (pTEZ30) was further used for the regio‐ and stereospecific dihydroxylations of various monosubstituted benzonitriles, benzyl cyanide, and cinnamonitrile. Biotransformations resulted in products with 42.9–97.1% enantiomeric excess. Initial enzymatic activities and isolated yields were obtained in the range of 1.7–4.7 U/g cdw and of 3–62%, respectively.
Analysis of mode transitions in biological networks
Authors: El‐Farra Nael H. , Gani Adiwinata , Christofides Panagiotis D. 
Published: May 2005

AbstractThis work presents a methodology for the analysis of mode transitions in biological networks. The proposed approach is predicated on the notion of orchestrating switching between the domains of attraction of the steady states of the constituent modes. Initially, the overall network is modeled as a switched nonlinear system that consists of multiple modes, each governed by a set of continuous‐time differential equations. The transitions between the continuous modes are triggered by discrete events (changes in model parameters that correspond to alterations in physiological conditions). Then, following the characterization of the steady‐state behavior of each mode, Lyapunov techniques are used to characterize the domains of attraction of the steady states. Finally, by analyzing how the domains of attraction of the various modes overlap with one other, a switching rule is derived to determine when, and if, a given mode transition at a given time results in the desired steady‐state behavior. The proposed method is demonstrated using models of biological networks that arise in cell cycle regulation and the bacteriophage λ‐switch system. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Mirrorless optical bistability in molecular aggregates with dipole–dipole interaction
Authors: Gusev V. V. 
Published: May 2005

AbstractThe possibility of mirrorless optical bistability in molecular aggregates with dipole–dipole interaction was studied theoretically. Dimers and ordered layers of the Langmuir–Blodgett type or J‐aggregates consisting of identical polyatomic fluorescent molecules were chosen as molecular aggregate models. The investigation was carried out on the basis of the Bogolubov equation chain for the density matrix of molecular aggregates and its components. It is shown that the fluorescence intensity and absorption ability are described by bistable and hysteresislike behaviour when the parameters of the molecular aggregate and pumping radiation are chosen suitably. An analysis of the bistability mechanism in such aggregates is given. Possibilities of controlling one light beam by another and switching polychromatic light flow by using a bistable device based on molecular aggregates are discussed.
Scanning tunnelling microscopy investigations of self‐assembled monolayers of poly(3‐decyl‐thiophene) on graphite
Authors: Bonfiglio Annalisa , Paradiso Rita , Di Zitti Ermanno , Ricci Davide , Bolognesi Alberto , Porzio William 
Published: May 2005

AbstractThe self‐assembly technique experimented for the deposition of alkanes and alkyl derivatives on layered compounds at the liquid/solid interface has been successfully extended to the adsorption of poly(3‐decyl‐thiophene) on graphite. The molecular films so obtained have been investigated using scanning tunnelling microscopy (STM). Images taken in both the constant‐current and constant‐height modes show highly packed arrays of molecules characterised by an average length and an average spacing that are in good agreement with results obtained by X‐ray diffraction investigations. Constant‐current images allow one to observe domain formations in preferential directions coincident with the main axes of the graphite lattice, while constant‐height imaging, performed on small areas, allows one to resolve atomic structures within the polymer backbone. In particular, periodic, 0.71 nm spaced features have been identified along the side of the polymer backbone; they can be associated with the length of two monomer units and are attributable to imaging of sulphur atoms in the backbone.
Langmuir–Blodgett films of indandione‐1,3 pyridinium betaine. I: Preparation, electronic structure, optical properties
Authors: Rutkis M. A. , Gerca L. E. , Silinsh E. A. , Neilands O. Y. , Roze M. P. , Berzinsh E. L. , Klimkans A. B. , Larsson S. 
Published: May 2005

AbstractThe synthesis of a new polar amphiphilic derivative of indandione‐1,3 pyridinium betaine (IPB) with different lengths of the aliphatic tail, containing 11 (C11IPB) and 17 (C17IPB) carbon atoms respectively, is described. The electronic structure (charge distribution, energy spectra, dipole moments in ground and excited states) of the IPB molecule has been calculated in the framework of the MO CNDO methods. Studies of compression π‐A isotherms of these compounds show that C17IPB forms two stable phases of monolayer on the water surface, one in the 10–30 mN m−1 and the other in the 35–50 nM m−1 surface pressure region. The corresponding areas A0 per molecule are 37 and 33 Å2 respectively. Techniques for the preparation of Langmuir‐Blodgett (LB) multilayers of C17IPB in the high‐pressure region (π = 40 mN m−1) on glass, quartz or sapphire substrates are described. C17IPB forms LB multilayer films of Z‐type configuration with oriented dipole moments. Ellipsometric data, luminescence spectra and results of preliminary studies of second‐harmonic generation in these LB films are presented.
In situ optical monitoring of the movpe growth of ZnSe on GaAs
Authors: Hayashi Keiji , Yoshino Junji , Kukimoto Hiroshi 
Published: May 2005

AbstractIn situ optical reflection measurement was employed to study surface processes during the MOVPE growth of ZnSe films under an alternate supply of diethylzinc (DEZn) and dimethylselenide (DMSe) using H2 and/or N2 as carrier gases. We have found that the time‐dependent reflection signal exhibits a unique saw‐toothed pattern during the DEZn supply, which is attributed to the adsorption and structural change of the DEZn. In contrast, the influence of DMSe on the time‐dependent signal appears to be rather marginal. A growth mechanism is proposed based on these experimental results, through which the important role of ambient hydrogen is discussed.
Growth modes of solution‐grown CdS thin films
Authors: Sebastian P. J. , Hu Hailin , Fernández A. M. 
Published: May 2005

AbstractThe growth modes of CdS thin films on glass in a chemical bath were analysed using scanning electron microscopy and optical microscopy. The results of these studies show that the film growth occurs by ion‐by‐ion condensation and by colloidal particles of CdS adhering to the substrate. Both mechanisms are operative from the initial stages of film growth. The predominance of one or other of these two growth modes depends on the abundance of Cd and S ions present in the solution, which is determined by the amount of complexing and sulphurising agents and ammonia used for the controlled release of Cd and S ions into the solution. The growth mode influences the optical properties of the films.
Cerebral hypoperfusion and clinical onset of dementia: The Rotterdam study
Authors: Ruitenberg Annemieke , den Heijer Tom , Bakker Stef L. M. , van Swieten John C. , Koudstaal Peter J. , Hofman Albert , Breteler Monique M. B. 
Published: May 2005

AbstractCerebral blood flow (CBF) velocity is decreased in patients with Alzheimer's disease. It is being debated whether this reflects diminished demand because of advanced neurodegeneration or that cerebral hypoperfusion contributes to dementia. We examined the relation of CBF velocity as measured with transcranial Doppler with dementia and markers of incipient dementia (ie, cognitive decline and hippocampal and amygdalar atrophy on magnetic resonance imaging) in 1,730 participants of the Rotterdam Study aged 55 years and older. Cognitive decline in the 6.5 years preceding CBF velocity measurement was assessed with repeated Mini‐Mental State Examinations in nondemented subjects (n = 1,716). Hippocampal and amygdalar volumes were assessed in a subset of 170 nondemented subjects. Subjects with greater CBF velocity were less likely to have dementia. Furthermore, in nondemented subjects, greater CBF velocity was related to significantly less cognitive decline over the preceding period (odds ratio per standard deviation increase in mean CBF 0.74 [95% confidence interval, 0.58–0.98]) and larger hippocampal and amygdalar volumes. A low CBF is associated with dementia, but also with markers of incipient dementia. Although we cannot exclude that this is caused by preclinical neurodegeneration leading to hypoperfusion, it does suggest that cerebral hypoperfusion precedes and possibly contributes to onset of clinical dementia. Ann Neurol 2005;57:789–794
Introducing an active cluster‐based information retrieval paradigm
Authors: Loureiro Oscar , Siegelmann Hava 
Published: June 2005

AbstractWhen a client interacts with an expert, e.g., a doctor, it falls upon the expert to ask questions that steer the process towards fulfilling the client's needs. This is most efficient given that the expert has more knowledge and a broader view of possible illnesses and treatments. On the other hand, when faced with an information retrieval (IR) task, most IR systems leave to the client the task of coming up with queries. We propose an information retrieval framework that assumes the responsibility of leading the users to the information, thus increasing efficiency and satisfaction.
User‐process model approach to improve user interface usability
Authors: Ju Boryung , Gluck Myke 
Published: June 2005

AbstractOur purpose in this study is to inductively reorganize software interface menu items based on a user's process model. The proposed menu interface in this study used direct users' input, such as goals and strategies for solving their information needs, to reorganize and re‐label menus. To assess its effectiveness, efficiency, and user satisfaction with actual users, we implemented and compared this new menu version to the original interface that was based upon a traditional categorical menu organization. The significance of this study is that it incorporates user process modeling into the design of the user interface, providing insights into the impact of such modeling on the usability of an information system. Results from the usability testing do indicate that the proposed menu and the traditional menu are similarly effective for users in terms of task completion time and accuracy. User preferences and debriefing comments from usability testing also indicate users preferred the user‐process based arrangement of menu items as displayed. However, the types of tasks (different problem type) suggest significant differences for results in task completion time and in accuracy, sometimes favoring the new version. In other words, usable and effective menu organization depends more on the types of tasks and the domain of knowledge than mere menu organization, although menu organization is a factor in the process.
Use of the z‐transform to investigate nanopulse penetration of biological matter
Authors: Su S. , Dai Weizhong , Haynie Donald T. , Simicevic N. 
Published: June 2005

AbstractShort duration, fast rise time electromagnetic ultra‐wideband (UWB) pulses (“nanopulses”) are generated by numerous electronic devices. Many new technologies involving nanopulses are under development and expected to become widely available soon. Study of nanopulse bioeffects therefore is needed to ensure human safety and to probe the useful range of nanopulses in possible biomedical and biotechnological applications. In this article, we present a new approximation of the Cole–Cole expression for the frequency dependence of the dielectric properties of tissues. The approximation is based on a z‐transformation of the electric displacement and a second‐order Taylor approximation of the Cole–Cole expression. The approach has been applied to investigating the penetration of nanopulses into biological matter as a function of the dielectric properties of tissue and pulse width. Solutions to Maxwell's equations are calculated using the finite difference time domain method (FDTD). Bioelectromagnetics 26:389–397, 2005. © 2005 Wiley‐Liss, Inc.
Antenna modeling considerations for accurate SAR calculations in human phantoms in close proximity to GSM cellular base station antennas
Authors: van Wyk Marnus J. , Bingle Marianne , Meyer Frans J.C. 
Published: June 2005

AbstractInternational bodies such as International Commission on Non‐Ionizing Radiation Protection (ICNIRP) and the Institute for Electrical and Electronic Engineering (IEEE) make provision for human exposure assessment based on SAR calculations (or measurements) and basic restrictions. In the case of base station exposure this is mostly applicable to occupational exposure scenarios in the very near field of these antennas where the conservative reference level criteria could be unnecessarily restrictive. This study presents a variety of critical aspects that need to be considered when calculating SAR in a human body close to a mobile phone base station antenna. A hybrid FEM/MoM technique is proposed as a suitable numerical method to obtain accurate results. The verification of the FEM/MoM implementation has been presented in a previous publication; the focus of this study is an investigation into the detail that must be included in a numerical model of the antenna, to accurately represent the real‐world scenario. This is accomplished by comparing numerical results to measurements for a generic GSM base station antenna and appropriate, representative canonical and human phantoms. The results show that it is critical to take the disturbance effect of the human phantom (a large conductive body) on the base station antenna into account when the antenna‐phantom spacing is less than 300 mm. For these small spacings, the antenna structure must be modeled in detail. The conclusion is that it is feasible to calculate, using the proposed techniques and methodology, accurate occupational compliance zones around base station antennas based on a SAR profile and basic restriction guidelines. Bioelectromagnetics 26:502–509, 2005. © 2005 Wiley‐Liss, Inc.
Solution structure of χ‐conopeptide MrIA, a modulator of the human norepinephrine transporter
Authors: Nilsson K. Peter R. , Lovelace Erica S. , Caesar Christina E. , Tynngård Nahreen , Alewood Paul F. , Johansson Helena M. , Sharpe Iain A. , Lewis Richard J. , Daly Norelle L. , Craik David J. 
Published: June 2005

AbstractThe χ‐conopeptides MrIA and MrIB are 13‐residue peptides with two disulfide bonds that inhibit human and rat norepinephrine transporter systems and are of significant interest for the design of novel drugs involved in pain treatment. In the current study we have determined the solution structure of MrIA using NMR spectroscopy. The major element of secondary structure is a β‐hairpin with the two strands connected by an inverse γ‐turn. The residues primarily involved in activity have previously been shown to be located in the turn region (Sharpe, I. A.; Palant, E.; Schroder, C. I.; Kaye, D. M.; Adams, D. J.; Alewood, P. F.; Lewis, R. J. J Biol Chem 2003, 278, 40317–40323), which appears to be more flexible than the β‐strands based on disorder in the ensemble of calculated structures. Analogues of MrIA with N‐terminal truncations indicate that the N‐terminal residues play a role in defining a stable conformation and the native disulfide connectivity. In particular, noncovalent interactions between Val3 and Hyp12 are likely to be involved in maintaining a stable conformation. The N‐terminus also affects activity, as a single N‐terminal deletion introduced additional pharmacology at rat vas deferens, while deleting the first two amino acids reduced χ‐conopeptide potency. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 80: 815–823, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Clinical significance of Ki-67 proliferation index in disease progression and prognosis of patients with resected colorectal carcinoma
Authors: Valera V , Yokoyama N , Walter B , Okamoto H , Suda T , Hatakeyama K 
Published: June 2005

Abstract

Background
The prognostic role of proliferation markers in patients with colorectal neoplasia is inconclusive. The aim of this study was to evaluate proliferation markers in patients with colorectal carcinoma, to relate these to standard clinicopathological findings and to investigate their potential role in the prediction of long-term survival.

Methods
Archived formalin-fixed, paraffin-embedded tissue samples from a cohort of 106 patients who underwent curative resection for colorectal carcinoma were analysed to determine a Ki-67 (MIB-1)-derived proliferation index (PI) using a double immunostaining technique. The relationship between PI and standard clinicopathological variables was assessed and its association with long-term survival evaluated.

Results
A significant association was found between PI and tumour (T) status (P = 0·001), lymph node (N) involvement (P = 0·0098), the presence of distant metastases (P &lt; 0·010) and advanced stage of disease (P &lt; 0·001). On multivariate analysis, PI was shown to be an independent prognostic factor for long-term survival (hazard ratio 2·1 (95 per cent confidence interval 1·1 to 4·1); P = 0·032).

Conclusion
Cell proliferation is significantly associated with tumour progression and may be used to identify patients with a predicted adverse outcome after resection of colorectal carcinoma.
Improvement in survival following surgery for colorectal cancer
Authors: McArdle C S , McKee R F , Finlay I G , Wotherspoon H , Hole D J 
Published: June 2005

Abstract

Background
Recent reports based on registry data have shown that survival after surgery for colorectal cancer is improving in the UK. It is not clear whether these improvements are due to earlier presentation or more effective treatment.

Methods
Outcome for 645 patients with colorectal cancer admitted to Glasgow Royal Infirmary between 1974 and 1979 was compared with that for 354 patients admitted between 1991 and 1994.

Results
More patients in the later period had Dukes' A or B tumours and fewer had evidence of metastatic spread (P &lt; 0·001); more underwent potentially curative resection (57·6 versus 49·9 per cent; P &lt; 0·001) and fewer underwent palliative diversion. The overall postoperative mortality rate fell from 14·1 to 8·5 per cent (P = 0·017). Overall and cancer-specific 5-year survival after potentially curative resection increased from 40·1 to 60·5 per cent and from 47·3 to 71·7 per cent respectively (both P &lt; 0·001). Compared with the earlier period, the adjusted hazard ratio for cancer-specific survival following potentially curative resection was 0·452 (95 per cent confidence interval 0·329 to 0·622; P &lt; 0·001).

Conclusion
The observed improvement in survival was mainly due to improvements in the quality of surgery and in perioperative care rather than earlier presentation.
Accuracy of computed tomography in the detection of blunt bowel and mesenteric injuries
Authors: Elton C , Riaz A A , Young N , Schamschula R , Papadopoulos B , Malka V 
Published: June 2005

Abstract

Background
There are conflicting views on the accuracy of computed tomography (CT) findings in patients with bowel and mesenteric injuries (BMIs) following blunt abdominal trauma. The aim of the present study was to assess the accuracy of the CT report during a trauma call.

Methods
Ninety-eight patients underwent preoperative abdominal spiral CT and subsequent laparotomy following blunt trauma between January 1996 and March 2001 at a level I trauma centre. The immediate results of the scans were reported by the on-call radiology registrar and written in the medical notes by the trauma team leader. Seventy of the 98 preoperative abdominal CT scans were retrieved from the radiology department and reported by two consultant radiologists with a special interest in trauma radiology.

Results
The sensitivity and specificity of the 70 expert CT reports were 80 (95 per cent confidence interval (c.i.) 66 to 94) and 78 (95 per cent c.i. 65 to 90) per cent respectively for diagnosing a BMI. The sensitivity and specificity of the immediate CT reports were 93 (95 per cent c.i. 84 to 100) and 71 (95 per cent c.i. 60 to 83) per cent respectively.

Conclusion
Spiral CT is highly sensitive for detecting a BMI following blunt abdominal trauma. This sensitivity is maintained when the scan is reported by a radiology registrar.
Incidence and management of pancreatic leakage after pancreatoduodenectomy
Authors: de Castro S M M , Busch O R C , van Gulik T M , Obertop H , Gouma D J 
Published: June 2005

AbstractBackgroundOptimal management of severe pancreatic leakage after pancreatoduodenectomy can reduce morbidity and mortality. Completion pancreatectomy may be adequate but leads to endocrine insufficiency. This study evaluated an alternative management strategy for pancreatic leakage.MethodsOutcome after disconnection of the jejunal limb, resection of the pancreatic body and preservation of a small pancreatic remnant, performed between 1997 and 2002, was compared with that after completion pancreatectomy performed between 1992 and 1996.ResultsPancreatoduodenectomy was performed in 459 consecutive patients. Pancreatic leakage occurred in 41 patients (8·9 per cent); its incidence did not change over the study period. Non-surgical drainage procedures were performed in 14 patients, of whom one died, and surgical drainage in eight patients, of whom two died. Completion pancreatectomy was performed in nine patients with no deaths. A pancreatic remnant was preserved in ten patients, of whom three died. A remnant tail had to be resected in two patients and three patients still developed endocrine insufficiency (‘brittle’ diabetes).ConclusionThe incidence of pancreatic leakage did not change over the study interval. Preservation of a small pancreatic tail was associated with higher morbidity and mortality rates than those of completion pancreatectomy.