bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic fields in jets: ordered or disordered?
Authors: Laing R. A. , Canvin J. R. , Bridle A. H.
Published: May 2006

The question of the degree of order in the magnetic fields of relativistic jets is important to any understanding of their production. Both vector‐ordered (e.g. helical) and disordered, but anisotropic fields can produce the high observed degrees of polarization. We outline our models of jets in FR I radio galaxies as decelerating relativistic flows. We then present theoretical calculations of the synchrotron emission from different field configurations and compare them with observed emission from FR I jets. We show that large‐scale helical fields (with significant poloidal and toroidal components) are inconsistent with observations. The combination of an ordered toroidal and disordered poloidal component is consistent with our data, as is an entirely disordered field. Jets must also contain small, but significant amounts of radial field. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Faraday rotation variations along radio jets: the magnetic field in galaxy and group halos
Authors: Laing R. A. , Canvin J. R. , Cotton W. D. , Bridle A. H. , Parma P.
Published: May 2006

Our modelling of FR I radio jets as decelerating, relativistic flows allows us to derive their orientations accurately. We present images of Faraday rotation for two of these these objects (3C 31 and NGC 315) and show that the fluctuations of rotation measure (RM) are larger in the fainter (receding) jets, as expected if the rotation occurs in the hot galaxy/group halos. The gas density is much lower in NGC 315 and the RM fluctuations are only just detectable. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
3D MHD interactions of jets with cluster media
Authors: O'Neill S. M. , Jones T. W. , Tregillis I. L. , Ryu D.
Published: May 2006

As an initial step in a program to examine the interactions of AGN jets with magnetized cluster media, we have carried out high resolution, 3D MHD medium‐to‐high luminosity jet simulations in both uniform and stratified, cluster‐like atmospheres extending over distances ∼ 200 kpc. The steady jets asymptotically deposit approximately 1/2 of their power into ambient thermal energy, almost independent of the jet Mach number or the external density gradient. Nearly 1/4 of the jet power goes directly into irreversible, dissipative heating of the ICM. The remaining energy is mostly stored in the jet backflow cocoon. Magnetic energy introduced by the jet is generally amplified, especially by sheared flows. We also examined the dynamical evolution of the jets and their cocoons, comparing them to simple analytic models. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
RM‐synthesis of the Perseus cluster
Authors: Brentjens M. A. , de Bruyn A. G.
Published: May 2006

We present low frequency radio polarimetric observations of the Perseus cluster. The data were taken with the Westerbork Synthesis Radio Telescope (WSRT) between 315–360 MHz. We have discovered faint, extended, highly polarized emission that we associate with the Perseus cluster (de Bruyn & Brentjens 2005). We propose that at least one of these structures is associated with large‐scale structure formation gas inflow from the Perseus‐Pisces supercluster. The extragalactic emission is seen through a polarized Galactic synchrotron foreground screen. The discovery was made possible by a novel rotation measure analysis technique, called Faraday Rotation Measure Synthesis, or RM‐synthesis for short (Brentjens & de Bruyn 2005). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constraining B in galaxy clusters from statistics of giant radio halos
Authors: Cassano R. , Brunetti G. , Setti G.
Published: May 2006

There are several possibilities to constrain the value of the magnetic field in the ICM, the most direct ones being the combination of inverse Compton and synchrotron observations, and the Faraday rotation measures. Here we discuss on the possibility to provide constraints on the magnetic field in the ICM from the analysis of the statistical properties of the giant radio halos, Mpc‐scale diffuse radio emission in galaxy clusters. Present observations of a few well studied radio halos can be interpreted under the hypothesis that the emitting relativistic electrons are re‐accelerated on their way out. By using statistical calculations carried out in the framework of the re‐acceleration model we show that the observed radiopower vs cluster mass correlation in radio halos can be reproduced only by assuming μG fields in the ICM and a scaling of the magnetic field with cluster mass B ∝ M b v, with b ≥ 0.6. We also show that the expected occurrence of radio halos with mass and redshift, and their number counts are sensitive to the magnetic field strength B in massive galaxy clusters and to the scaling of B with cluster mass. Thus future deep surveys of radio halos would provide constraints on B in galaxy clusters. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diffuse radio sources in groups and poor clusters
Authors: Delain K. M. , Rudnick L.
Published: May 2006

We have discovered new diffuse radio sources likely associated with groups of galaxies at low redshift (0.01–0.04) and without apparent AGN by using the WENSS and WISH catalogs to perform an unbiased survey. These sources resemble the radio halos, mini‐halos, and ‘relics’ of rich clusters, which are thought to be powered by shocks and turbulence from infall into their deep potential wells. Our detection of similar sources within the shallow potential wells of groups of galaxies may challenge this model. Their radio luminosities are approximately two orders of magnitude higher than expected from the extrapolation of the apparent rich cluster radio/X‐ray luminosity relation. Even if these sources are misidentified distant clusters, they would lie above the apparent rich cluster radio/X‐ray luminosity relation in the literature, suggesting that detections of radio halos and relics thus far may be more biased than previously thought. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New radio halos and relics in clusters of galaxies
Authors: Giovannini G. , Feretti L. , Govoni F. , Murgia M. , Pizzo R.
Published: May 2006

We present here new images of relics and halo sources in rich cluster of galaxies and the correlation between the halo radio surface brightness versus the cluster bolometric X‐ray luminosity. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral index maps of radio halos and relics
Authors: Orrù E. , Feretti L. , Govoni F. , Murgia M. , Giovannini G. , Brunetti G. , Setti G.
Published: May 2006

New VLA observations at 90 cm are presented for the clusters of galaxies Abell 2219 and Abell 2744, which are characterized by the presence of a radio halo and relic. These sources are suggested to originate from particles reaccelerated in the cluster central regions, possibly by turbulence following major merger events. The study of the spectral properties of these sources is of great importance for the knowledge of the characteristics of relativistic particles and magnetic fields on large scales. Combining images at 90 and 20 cm, we obtained the spectral index distribution of the diffuse radio sources with a resolution of 1′.We produced radial brightness profiles at the two wavelengths, from which we calculated the radial spectral index trend. Our main result is that the spectral index shows a steepening with increasing distance from the cluster center to the edge. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radio haloes in galaxy clusters: what do they tell us about the cluster's magnetic field?
Authors: Eilek J. , Owen F. , Marković T.
Published: May 2006

Our new radio observations of a complete, X‐ray selected sample of clusters of galaxies suggest that diffuse radio haloes exist in all clusters, not just those undergoing a major merger. Some of our detected haloes are in clusters with strong cooling cores, which are thought to be dynamically relaxed. We infer that the plasma in every cluster contains relativistic particles and magnetic fields, whether or not the cluster has recently undergone a major merger. We do not know, however, what energizes the plasma in relaxed clusters. The answer could be mesoscale fluctuations in the underlying dark matter, or energy input from active galaxies, or a mixture of both. In addition, Faraday rotation from the plasma seems to require a magnetic field significantly stronger than that inferred from simple analyses of the radio haloes and/or hard X‐ray emission. We suspect this apparent problem comes from our incomplete understanding of magnetic structures and relativistic plasmas in the cluster; we suggest an alternative way to interpret radio and hard X‐ray data. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The radio luminosity function of radio galaxies in distant clusters
Authors: Branchesi M. , Gioia I. M. , Fanti C. , Fanti R. , Perley R.
Published: May 2006

A complete sample of 18 X‐ray selected clusters of galaxies belonging to the ROSAT North Ecliptic Pole (NEP) survey has been observed with the Very Large Array at 1.4 GHz. These are the most distant clusters in the X‐ray survey with redshift in the range 0.3 < z < 0.8. 79 radio sources are detected within half an Abell radius with an observed peak brightness ≥ 0.17 mJy beam–1. 32 out of the 79 sources are within 0.2 Abell radius, 22 of them are considered cluster members based on spectroscopic redshifts or their optical magnitude and morphological classification. The cluster radio galaxies are used to construct the radio luminosity function (RLF) of distant X‐ray selected clusters. A comparison with two nearby cluster RLFs shows that the NEP RLF lies above the local ones, has a steeper slope at low radio powers (≤ 1024 WHz–1) and shows no evidence for a break at ≈ 6 × 1024 WHz–1 which is observed in the nearby cluster RLFs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulating large‐scale structure formation with magnetic fields
Authors: Dolag K.
Published: May 2006

In the past, different works based on numerical simulations have been presented to explain magnetic fields (MFs) in the large scale structure and within galaxy clusters. In this review, I will summarize the main findings obtained by different authors and – even if many details are still unclear – I will try to construct a consistent picture of our interpretation of largescale magnetic fields based on numerical effort. I will also sketch how this is related to our understanding of radio emission and summarize some arguments where our theoretical understanding has to be improved to match the observations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The origin and evolution of cluster magnetism
Authors: Shukurov A. , Subramanian K. , Haugen N. E. L.
Published: May 2006

Random motions can occur in the intergalactic gas of galaxy clusters at all stages of their evolution. Depending on the poorly known value of the Reynolds number, these motions can or cannot become turbulent, but in any case they can generate random magnetic fields via dynamo action. We argue that magnetic fields inferred observationally for the intracluster medium require dynamo action, and then estimate parameters of random flows and magnetic fields at various stages of the cluster evolution. Polarization in cluster radio halos predicted by the model would be detectable with the SKA. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New mechanism of generation of large‐scale magnetic fields in merging protogalactic and protostellar clouds
Authors: Rogachevskii I. , Kleeorin N. , Chernin A. D. , Liverts E.
Published: May 2006

A new mechanism of generation of large‐scale magnetic fields in colliding protogalactic clouds and merging protostellar clouds is discussed. Interaction of the colliding clouds produces large‐scale shear motions which are superimposed on small‐scale turbulence. Generation of the large‐scale magnetic field is due to a “shear‐current” effect (or “vorticity‐current” effect), and the mean vorticity is caused by the large‐scale shear motions of colliding clouds. This effect causes the generation of the mean magnetic field even in a nonrotating and nonhelical homogeneous turbulence. There is no quenching of the nonlinear shear‐current effect contrary to the quenching of the nonlinear alpha effect, the nonlinear turbulent magnetic diffusion, etc. During the nonlinear growth of the mean magnetic field, the shear‐current effect only changes its sign at some value of the mean magnetic field which determines the level of the saturated mean magnetic field. Numerical study shows that the saturated level of the mean magnetic field is of the order of the equipartition field determined by the turbulent kinetic energy. The estimated large‐scale magnetic field for merging protogalactic clouds is about several microgauss, and for merging protostellar clouds is of the order of several tenth of microgauss. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Divergence cleaning techniques in smoothed particle magnetohydrodynamics simulations
Authors: Ziegler E. , Dolag K. , Bartelmann M.
Published: May 2006

Smoothed Particle Magnetohydrodynamics (SPMHD) algorithms are tested with a Brio & Wu shocktube in order to find a suitable algorithm for treating magnetic shocks in clusters of galaxies. In particular the treatment of a nonvanishing divergence of B is discussed because of its appearance due to numerical errors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Japanese X‐ray missions
Authors: Fujita Y.
Published: May 2006

Here, I briefiy introduce Japanese X‐ray missions: Suzaku and NeXT . Suzaku was launched on July 10, 2005. NeXT will be launched in 2011. They will open new windows into the workings of black holes, clusters of galaxies, active galaxies, and other very energetic objects. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defunctioning stomas in the treatment of rectal cancer
Authors: Morton D G , Sebag Montefiore D
Published: May 2006

Limited knowledge causes variation in practice
Tissue engineering of vascular conduits
Authors: Yow K-H , Ingram J , Korossis S A , Ingham E , Homer-Vanniasinkam S
Published: May 2006

Background

Autologous conduits are not available in up to 40 per cent of patients with arteriopathy who require coronary or lower limb revascularization, and access sites for renal dialysis may eventually become exhausted. Synthetic prostheses achieve a poor patency rate in small-calibre anastomoses. This review examines how vascular tissue engineering may be used to address these issues.

Methods

A Medline search was performed, using the keywords ‘vascular tissue engineering’, ‘small diameter vascular conduit’, ‘vascular cell biology’, ‘biomechanics’, ‘cell seeding’ and ‘graft endothelialization’. Key references were hand-searched for relevant papers.

Results and conclusion

In vitro and in vivo approaches are currently being used for guided cell repopulation of both biological and synthetic scaffolds. The major clinical problem has been extended culture time (approximately 6 weeks), which precludes their use in the acute setting. However, recent advances have led not only to improved patency rates for prostheses, but also to a potential reduction in culture time. In addition, increased mobilization of endothelial progenitor cells in the presence of ischaemic tissue may increase the autologous cell yield for scaffold reseeding with further reduction in culture time.
Population-based study of the diagnosis and treatment of gastrointestinal stromal tumours
Authors: Bümming P , Ahlman H , Andersson J , Meis-Kindblom J M , Kindblom L-G , Nilsson B
Published: May 2006

Background

The aim of this retrospective population-based study, which was conducted before the introduction of imatinib, was to evaluate the role of surgery in patients with gastrointestinal stromal tumours (GISTs) and clarify which subgroups might benefit from adjuvant treatment.

Methods

Two hundred and fifty-nine patients with clinically detected GISTs were studied. Univariate and multivariate analyses were performed to identify predictors for recurrent disease and survival.

Results

Thirty of 48 patients with high-risk GISTs and all of those with overtly malignant tumours developed recurrent tumour after complete (R0) resection. Thirty-four of 38 first recurrences occurred within 36 months of surgery. No recurrence was observed after 72 months. R0 resection, achieved in 48 (80 per cent) of 60 patients with high-risk tumours, was significantly associated with a decreased risk of death from tumour recurrence (P = 0·008).

Conclusion

Completeness of surgical resection is an independent prognostic factor in patients with high-risk GISTs. A period of adjuvant treatment with imatinib is recommended in patients with high-risk or overtly malignant GISTs who have undergone R0 resection and have a tumour-free interval of less than 6 years.
Systematic review of outcome of synchronous portal–superior mesenteric vein resection during pancreatectomy for cancer
Authors: Siriwardana H P P , Siriwardena A K
Published: May 2006

Background

Tumour clearance during pancreatectomy may be facilitated by resection of the portal–superior mesenteric vein, but this is associated with increased perioperative risk. There is no consensus about which patients benefit from portal–superior mesenteric vein resection.

Methods

A systematic appraisal was carried out of the literature on portal–superior mesenteric vein resection during pancreatectomy to identify recurrent themes to guide management. A computerized search of the Medline and Embase databases found 52 non-duplicated studies providing relevant data in 1646 patients. Pooled data were examined for information on outcome categories relating to operation, complications, histopathology and overall outcome.

Results

The median (range) number of patients with portal–superior mesenteric vein resection per cohort was 23 (4–172). Median operating time was 513 (168–1740) min and blood loss 1750 (300–26000) ml. Postoperative morbidity ranged from 9 to 78 per cent with a median per cohort of 42 per cent. There were 73 perioperative deaths (5·9 per cent of 1235 for whom mortality data were provided). Median survival was 13 months, and 1-, 3- and 5-year survival rates were 50, 16 and 7 per cent respectively. Specimen histopathology confirmed positive nodes in 67·4 per cent.

Conclusions

This is the largest collective report to date on portal–superior mesenteric vein resection in pancreatectomy. The high rate of nodal metastases and low 5-year survival rates suggest that by the time of tumour involvement of the portal vein cure is unlikely, even with radical resection.
Randomized clinical trial to evaluate the effects of perioperative supplemental oxygen administration on the colorectal anastomosis
Authors: García-Botello S A , García-Granero E , Lillo R , López-Mozos F , Millán M , Lledó S
Published: May 2006

Background

Perioperative supplemental oxygen therapy may have beneficial effects on wound healing following colorectal surgery. The aim of this study was to evaluate the effects of such therapy on colorectal anastomotic pH and partial pressure of carbon dioxide (Pco2) gap.

Methods

Forty-five patients undergoing anterior resection for rectal or sigmoid cancer were randomized to receive 30 or 80 per cent perioperative oxygen. Administration was commenced after induction of anaesthesia and maintained for 6 h after surgery. Intragastric and anastomotic tonometric catheters were placed in each patient and intramucosal pH (pHi) was measured immediately after operation, and 6 and 24 h later. Gastric and anastomotic pHi and Pco2 gap in each group were compared.

Results

There was a significantly lower anastomotic pHi and wider Pco2 gap for gastric readings in the 30 per cent O2 group, both 30 min (pHi, P = 0·006; Pco2 gap, P = 0·006) and 6 h (pHi, P = 0·024; Pco2 gap, P = 0·036) after surgery. There were no differences 24 h after surgery while breathing room air (pHi, P = 0·131; Pco2 gap P = 0·139). No difference was found between gastric and anastomotic readings at any time point in the 80 per cent O2 group.

Conclusion

Perioperative administration of 80 per cent O2 both during surgery and for 6 hours afterwards is associated with an improvement in relative anastomotic hypoperfusion as assessed by the measurement of pHi and Pco2 gap.
Meta-analysis of prophylactic antibiotic use in acute necrotizing pancreatitis
Authors: Mazaki T , Ishii Y , Takayama T
Published: May 2006

Background

Death from infected necrosis in acute pancreatitis is common and prevention has focused on prophylactic antibiotics. This study assesses whether intravenous prophylactic antibiotic use reduces infected necrosis and death in acute necrotizing pancreatitis.

Methods

A meta-analysis of randomized controlled trials was carried out. Medline, Web of Science, the Cochrane controlled trials register and international conference proceedings were searched, with a citation review of relevant primary and review articles.

Results

Six of 328 studies assessed were included in data extraction. Primary outcome measures were infected necrosis and death. Secondary outcome measures were non-pancreatic infections, surgical intervention and length of hospital stay. Prophylactic antibiotic use was not associated with a statistically significant reduction in infected necrosis (relative risk (RR) 0·77 (95 per cent confidence interval (c.i.) 0·54 to 1·12); P = 0·173), mortality (RR 0·78 (95 per cent c.i. 0·44 to 1·39); P = 0·404), non-pancreatic infections (RR 0·71 (95 per cent c.i. 0·32 to 1·58); P = 0·402) and surgical intervention (RR 0·78 (95 per cent c.i. 0·55 to 1·11); P = 0·167). It was, however, associated with a statistically significant reduction in hospital stay (P = 0·040).

Conclusion

Prophylactic antibiotics do not prevent infected necrosis or death in acute necrotizing pancreatitis.
Quantification of zolpidem in human plasma by high‐performance liquid chromatography with fluorescence detection
Authors: Nirogi Ramakrishna V. S. , Kandikere Vishwottam N. , Shrivasthava Wishu , Mudigonda Koteshwara
Published: May 2006

A simple, reliable HPLC method with fluorescence detection (excitation 320 and emission 388 nm) was developed and validated for quantitation of zolpidem in human plasma. Following a single‐step liquid–liquid extraction, the analyte and internal standard (quinine) were separated using an isocratic mobile phase on a reversed‐phase C18 column. The lower limit of quantitation was 1.8 ng/mL, with a relative standard deviation of less than 5%. A linear dynamic range of 1.8–288 ng/mL was established. This HPLC method was validated with between‐batch and within‐batch precision of 1.7–4.8 and 1.2–2.3%, respectively. The between‐batch and within‐batch accuracy was 95.3–100.4 and 95.5–102.7%, respectively. Frequently coadministered drugs did not interfere with the described methodology. Stability of zolpidem in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is simple and repeatable enough to be used in pharmacokinetic studies. Copyright © 2006 John Wiley & Sons, Ltd.
Integrating hotel environmental strategies with management control: a structuration approach
Authors: Chung Lai Hong , Parker Lee D.
Published: May 2006

This study addresses the development of environmental strategies and associated management control in the international hotel industry, a sector of major economic and environmental impact hitherto largely neglected in the environmental management and accountability literature. The low key level of commitment to environmental management currently exhibited by the industry is considered in the context of dominant systems of hotel management performance evaluation and control, as well as the industry's current strategic management and budgetary practices. Informed by Giddens' structuration theory, the study offers a new theoretical framework, environmentally efficient resourcing, as a structured approach to the development of hotel environmental strategy and its management. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Kidnapping: a criminal profile of persons convicted 1979–2001
Authors: Soothill Keith , Francis Brian , Ackerley Elizabeth
Published: May 2006

Kidnapping has been a neglected crime in criminological research. In fact, there has been a dramatic increase in the yearly numbers of police recorded kidnapping offences in England and Wales in the last 25 years, but this has not been matched by a similar increase in convictions. This study focuses on the official criminal histories of the 7042 males and 545 females who were convicted at least once for kidnapping between 1979 and 2001. Of these, 3.9% of the males and 2.6% of the females had convictions for kidnapping on more than one occasion.

We examined two subgroups to ensure long observation periods for prior and subsequent convictions. Of those convicted of kidnapping in 2001, around one‐half (51.1%) of the males and around one‐third (36.6%) of the females hadpreviousconvictions. The previous convictions consist of a wide range of offences, with the most common being theft and violent offences. A 20‐year follow‐up of those convicted in 1979–81 showed that three in five males and one in three females are subsequently convicted on at least one more occasion for a standard‐list offence.

An examination of convictions for other offences brought to court at the same time as the kidnap offence enabled a typology of kidnaps to be proposed. Those kidnaps with co‐convictions of an acquisitive nature declined over the period, whereas other types, including sexual and violent, showed rises. Changing shifts in the nature of kidnaps have important policy implications. Copyright © 2006 John Wiley & Sons, Ltd.
Delusional disorder and delusions: is there a risk of violence in social interactions about the core symptom?
Authors: Taylor Pamela J.
Published: May 2006

Delusional disorders are rare, but psychoses with prominent and persistent delusions are less so. A small but significant association between psychosis and violence is often mediated by delusions in such illnesses. Traditionally, delusions have been viewed as “incorrigible”, but there is evidence that they change over time.

During development of a scale for measuring delusions, it was found that people who acted violently on their “most important” delusion were more likely to have modified that belief after a mild form of challenge to it. When cognitive–behaviour therapy (CBT) is used for schizophrenia, attempts to modify psychotic symptoms are generally included. Could studies of CBT provide further information about possible risks of social interactions about delusions?

In the UK, 2000 people with schizophrenia have been in randomized controlled trials of CBT with a goal of symptom modification. These studies were examined for evidence of violence during the treatment. There was none. Given the period prevalence of violence among people with psychosis, this is surprising. In these studies, however, both challenge to delusions and change in them was minimal and in the context of a safe clinical relationship.

Challenge to delusions may, however, occur in a variety of social situations. There are no systematic data on lay challenge to them, but it seems likely that some in the sufferer's social circle will do so vigorously. Relatives, friends, and acquaintances are the people most vulnerable to the most serious violence by someone with psychosis. Study of how people interact in these circumstances and whether their interactions are relevant to modification of delusions would be worthwhile. Could those close to a sufferer learn skills for responding to such pathological beliefs that could be protective against violence, perhaps derived from the principles of CBT?. Copyright © 2006 John Wiley & Sons, Ltd.
Enhancing the informed consent process: a conceptual overview
Authors: Eyler Lisa T. , Jeste Dilip V.
Published: May 2006

Concern about limitations in the ability to give valid informed consent among certain groups of individuals has led to increased interest in defining, measuring, and enhancing consent‐related decision‐making. In this overview, we summarize issues related to the definition of decision‐making capacity, discuss methods that have been used to assess decision‐making abilities and other aspects of informed consent, and briefly describe studies that aim to understand variation in different elements of informed consent. We then review strategies that have been used with the intent of improving aspects of the informed consent process. Finally, we provide an outline of areas that are in need of future studies in order to reach the ultimate goal of preserving as much autonomy as possible in at‐risk populations, while still achieving valuable research and treatment goals. Published in 2006 by John Wiley & Sons, Ltd.
Synthesis, Structural Analysis, and Visualization of a Library of Dendronized Polyphenylacetylenes
Authors: Percec Virgil , Rudick Jonathan G. , Peterca Mihai , Staley Sasha R. , Wagner Martin , Obata Makoto , Mitchell Catherine M. , Cho Wook‐Dong , Balagurusamy Venkatachalapathy S. K. , Lowe James N. , Glodde Martin , Weichold Oliver , Chung Kyung J. , Ghionni Nicholas , Magonov Sergei N. , Heiney Paul A.
Published: May 2006

A library of eleven high cis‐content cis‐transoidal polyphenylacetylenes (PPAs) dendronized with self‐assembling dendrons was prepared from a library of fifteen convergently synthesized macromonomers. Using [Rh(CCPh)(nbd)(PPh3)2] (nbd=2,5‐norbornadiene) in the presence of 10 equiv of N,N‐dimethylaminopyridine, predictive control over molecular weight and narrow molecular weight distribution are obtained. The PPA backbone serves as a helical scaffold for the self‐assembling dendrons. The dendron primary structure dictates the diameter of the cylindrical PPAs in bulk, both in the self‐organized hexagonal columnar (${{\Phi}{{\hfill \atop {\rm h}\hfill}}}$) lattice determined by X‐ray diffraction (XRD) and in monolayers on highly ordered pyrolytic graphite (HOPG) and mica visualized by atomic force microscopy (AFM). Thermal and bulk phase characteristics of the cylindrical PPAs reinforces the generality that flexible polymer backbones adopt a helical conformation within the cylindrical macromolecules generated by polymers jacketed with self‐assembling dendrons.
Asymmetric Amplification by Kinetic Resolution Using A Racemic Reagent: Example in Amine Acetylation
Authors: Satyanarayana Tummanapalli , Kagan Henri B.
Published: May 2006

The reaction of a racemic reagent on a mixture of enantiomers with small ee (ee=enantiomeric excess) has been studied for amine acylation. A substantial asymmetric amplification could be realized, for example, from 67 to >95.5 ee. The combination of asymmetric amplifications is subsequently discussed. Two sequential asymmetric amplifications, one using a racemic reagent and another using a positive nonlinear effect allowed us to start from 1.5 % ee and end with a large amount of a product of 97 % ee.
Ethylene Oligomerisation and Polymerisation with Nickel Phosphanylenolates Bearing Electron‐Withdrawing Substituents: Structure–Reactivity Relationships
Authors: Kuhn Pierre , Sémeril David , Jeunesse Catherine , Matt Dominique , Neuburger Markus , Mota Antonio
Published: May 2006

Three SHOP‐type catalysts, in which the CC(O) double bond was substituted by electron‐withdrawing substituents, [Ni{Ph2PC(R1)C(R2)O}Ph(PPh3)] (2: R1,R2 = C(Me)NN(Ph); 3: R1 = CO2Et, R2 = Ph; 4: R1 = CO2Et, R2 = CF3), were assessed as ethylene‐oligomerisation and ‐polymerisation catalysts and compared to Keim's complex, [Ni{Ph2PCHC(Ph)O}Ph(PPh3)] (1). A rationale for the influence of the double‐bond substituents of the P,O‐chelate unit on the catalytic properties is proposed, on the basis of X‐ray diffraction studies, spectroscopic data and DFT‐B3 LYP calculations. Whatever their relative electron‐withdrawing strength, the R1 and R2 substituents induce an increase in activity with respect to catalyst 1. For those systems in which the basicity of the oxygen atom is decreased relative to that of the phosphorus atom, the chain‐propagation rate increases with respect to that for catalyst 1. Reduction of the basicity of the P relative to that of the O, however, induces higher chain‐termination rates.
A Novel Strategy for the Key Fully Substituted Cyclopentenedione Moiety of Madindolines via AlEt3‐promoted Tandem Reductive Rearrangement of α‐Hydroxy Epoxides
Authors: Gao Shuan‐Hu , Jia Yan‐Xing , Zhao Xue‐Zhi , Tu Yong‐Qiang
Published: May 2006

The fully substituted cyclopentenedione core of madindoline A (1) and B (2) as potent and selective inhibitor of IL‐6 has been synthesized efficiently. The quaternary carbon center C‐2′ was constructed on the basis of a newly developed AlEt3‐promoted tandem reductive rearrangement of α‐hydroxy epoxides.
Using Acetylene for Selective Catalytic Reduction of NO in Excess Oxygen
Authors: Yu Shan‐Shan , Wang Xin‐Ping , Wang Chong , Xu Yan
Published: May 2006

Acetylene as a reducing agent for selective catalytic reduction of NO (C2H2‐SCR) was investigated over a series of metal exchanged HY catalysts, in the reaction system of 0.16% NO, 0.08% C2H2, and 9.95% O2 (volume percent) in He. 75% of NO conversion to N2 with hydrocarbon efficiency about 1.5 was achieved over a Ce‐HY catalyst around 300 °C. The NO removal level was comparable with that of selective catalytic reduction of NOx by C3H6 reported in literatures, although only one third of the reducing agent in carbon moles was used in the C2H2‐SCR of NO. The protons in zeolite were crucial to the C2H2‐SCR of NO, and the performance of HY in the reaction was significantly promoted by cerium incorporation into the zeolite. NO2 was proposed to be the intermediate of NO reduction to N2, and the oxidation of NO to NO2 was rate‐determining step of the C2H2‐SCR of NO over Ce‐HY. The suggestion was well supported by the results of the NO oxidation with O2, and the C2H2 consumption under the conditions in the presence or absence of NO.
Evaluation of Two‐center One‐ and Two‐electron Integrals over Slater Type Orbitals
Authors: Yakar Yusuf , Özmen Ayhan , Atav Ülfet
Published: May 2006

A formulation previously presented by the authors for coulomb integrals was generalized to other two‐center integrals, except exchange integral. Within this frame, molecular integrals were expressed in terms of some new functions closely related to the well‐known incomplete gamma functions and these functions recursively evaluated. Special issues arising in the case of hybrid integrals were addressed, and the results were compared with the ones found in the literature.
Influence of Low Cetyltrimethylammonium Bromide Concentration on the Interactions and Properties of Hemoglobin with Acyclovir
Authors: Liu Tian‐Qing , Guo Rong
Published: May 2006

The effects of cetyltrimethylammonium bromide (CTAB) on the properties of hemoglobin (Hb) at low CTAB concentration were studied in Hb/acyclovir/CTAB system by the methods of UV‐Vis spectrum, fluorescence, zeta potential, conductivity and negative‐staining transmission electron microscope (TEM). With the increase of CTAB concentration, the UV peak intensity at 276 nm, the intrinsic fluorescence, the zeta potential of Hb and the system conductivity were all enhanced. Hb was easily oxidized to oxyHb and hemichrome. In Hb/acyclovir/CTAB system, CTAB made the UV‐Vis spectrum, fluorescence, conductivity and conformation of Hb tend to be returned to those of the original Hb but the zeta potential not to do so. The UV absorption peak of Hb‐acyclovir complex disappeared, and the tight structure of Hb aroused by acyclovir was refolded. When CTAB concentration was higher than 5×10−5 mol/L, the two absorption peaks at 536 and 576 nm appeared again, and the Hb structure became looser again.
Investigation of the Inhibition of Cyanide on Metabolism of Fish Liver Mitochondria by Microcalorimetry
Authors: Li Hui‐Rong , Liu Yi , Dai Jie , Qin Cai‐Qin , Zhang Zhong‐Hai , Qu Song‐Sheng
Published: May 2006

A microcalorimetric technique based on the metabolic heat‐output was explored to evaluate the inhibition of cyanide on the mitochondrial metabolism of aquatic animal, Cyprinus carpio. The power‐time curves could be divided into four parts:lag phase, active recovery phase, stationary phase, and decline phase, and the corresponding thermokinetic parameters were obtained. The maximum heat production rate Pmax decreased in a linear manner with the increase of concentration of cyanide, however, such mitochondria of aquatic animal were still metabolized actively even under the action of high concentration of cyanide. All the observations suggested that the mitochondria of this aquatic animal should exhibit considerable ability of cyanide‐resistant respiration.
Estimation of the Kinetic Parameters and the Critical Rate of Temperature Rise in the Thermal Explosion from the Exothermic Autocatalytic Decomposition of 3,4‐Bis(4′‐nitrofurazan‐3′‐yl)‐2‐oxofurazan (BNFOF) Using Non‐isothermal Differential Scanning Calorimetry
Authors: Zhao Feng‐Qi , Guo Peng‐Jiang , Hu Rong‐Zu , Zhang Hai , Xia Zhi‐Ming , Gao Hong‐Xu , Chen Pei , Luo Yang , Zhang Zhi‐Zhong , Zhou Yan‐Shui , Xiao Qin , Zhao Hong‐An , Gao Sheng‐Li , Shi Qi‐Zhen , Lu Gui‐E , Jiang Jin‐Yong
Published: May 2006

A method of estimating the kinetic parameters and the critical rate of temperature rise in the thermal explosion for the autocatalytic decomposition of 3,4‐bis(4′‐nitrofurazan‐3′‐yl)‐2‐oxofurazan (BNFOF) with non‐isothermal differential scanning calorimetry (DSC) was presented. The rate equation for the decomposition of BNFOF was established, and information was obtained on the rate of temperature increase in BNFOF when the empiric‐order autocatalytic decomposition was converted into thermal explosion.
Synthesis, Characterization, Crystal Structure and Quantum Chemical Calculation of Novel Compound1,3‐Dimethyl‐2‐ferrocenylmethylbenzimidazolium Iodide
Authors: Zhang Jing , Yang Bing‐Qin , Zhu Hai‐Yan , Li Tao , Wen Zhen‐Yi
Published: May 2006

A novel benzimidazole derivative, 1,3‐dimethyl‐2‐ferrocenylmethylbenzimidazolium iodide (1) was synthesized and characterized by elemental analysis, MS, 1H NMR and IR spectra. Its crystal structure was determined by X‐ray single crystal diffraction, and the title compound belongs to monoclinic system with space group P2(1)/c. According to the crystal structure, the quantum chemistry calculation was performed by Gaussian 03 program, and full geometry optimizations of the title compound were carried out with DFT method at B3LYP/6‐31G level. Its structure, stability, frontier molecular orbital components and net charge distribution were discussed.
Fast Determination of Essential Oil from Dried Menthol Mint and Orange Peel by Solvent Free Microwave Extraction Using Carbonyl Iron Powder as the Microwave Absorption Medium
Authors: Wang Zi‐Ming , Ding Lan , Wang Lu , Feng Jin , Li Tie‐Chun , Zhou Xin , Zhang Han‐Qi
Published: May 2006

An improved solvent free microwave extraction, in which a kind of microwave absorption medium (carbonyl iron powder) was used, was applied to the extraction of essential oil from dried menthol mint and orange peel without addition of any solvent and pretreatment. It took much less time of extraction (30 min) than microwave‐assisted hydrodistillation (90 min) and conventional hydrodistillation (180 min). The kinds of chemical compositions in essential oil extracted by different methods were almost the same and such improved solvent free microwave extraction can be a feasible way in extraction of essential oil from dried plant materials.
Effect of Denaturant Concentration on Hen‐egg White Lysozyme Renaturation
Authors: Bian Liu‐Jiao , Yang Xiao‐Yan
Published: May 2006

Based on three‐state renaturation process of denatured proteins, an equation describing the effect of denaturant concentration on renaturation yield of denatured proteins was presented. By this equation, two parameters n(m1−m2) and Ka can be obtained. The former indicates the difference in the number of denaturant molecules between the renaturation process of n number of refolding intermediates from refolding intermediate state to native state and their aggregate process from refolding intermediate state to aggregate state, the latter denotes the apparent aggregate equilibrium constant for protein molecules aggregated from native state to aggregate state, and from them, the characteristics of the renaturation process of denatured proteins in denaturant solution can be identified. This equation was tested by the renaturation processes of denatured egg white lysozyme in guanidine hydrochloride and urea solutions, with the results to show that when guanidine hydrochloride and urea concentrations were separately higher than 1.25 and 3.00 mol/L or separately lower than 1.00 and 3.00 mol/L, the refolding intermediates of egg white lysozymes were more easily aggregated to aggregate state or more easily renatured to native state, respectively. Under different initial total egg white lysozyme concentrations in urea solution, the refolding egg white lysozyme intermediates could be deduced to have a tendency to form a bimolecular intermediate aggregate, and this inference was further confirmed by their nonreducing SDS‐PAGE and size exclusion chromatography.
Study on Interaction of Ginsenosides with Bovine or Human Serum Albumin Using Wavelength Modulation Surface Plasmon Resonance Biosensor
Authors: Liu Xia , Sun Ying , Song Da‐Qian , Li Xu‐Wen , Zhang Qing‐Lin , Tian Yuan , Liu Zhong‐Ying , Zhang Han‐Qi
Published: May 2006

To use a newly developed wavelength modulation surface plasmon resonance (SPR) biosensor, an experimental protocol was developed to investigate the interaction of ginsenosides with serum albumin. With a known concentration of the ginsenosides, bound percentages of the ginsenosides with human serum albumin (HSA) or bovine serum albumin (BSA) were obtained. SPR technique could require no labeling and this method provided the detailed information on association and disassociation of molecules in real time. The results indicate that the sensitivity of wavelength modulation SPR biosensor is sufficient for detection and characterization of binding events involving low‐molecular weight compounds and their immobilized protein targets.
Synthesis, Structure and Ion Extraction Properties of Novel Monooxa‐diselkylene‐1,ω‐dioxy Substituted Calix[4]arene Derivatives
Authors: Qin Da‐Bin , Zeng Xian‐Shun , Xu Feng‐Bo , Li Qing‐Shan , Zhang Zheng‐Zhi
Published: May 2006

Novel macrocyclic monooxa‐diselkylene‐1,ω‐dioxy substituted calix[4]arene derivatives 1a–5a were synthesized by the reaction of calix[4]arene dibromides 1–5 with the disodium salt of bis(2‐selenylethyl)ether in the yields between 28% and 64%. Their structures were characterized by proton and carbon NMR spectra. X‐Ray structure analysis of 1a further confirmed the cone conformation of compounds 1a–5a. An interesting host‐guest complex of 1a with dichloromethane via CH/π and Cl/π interactions was elucidated. Extraction experiments showed that these novel monooxa‐diselkylene‐1,ω‐dioxy substituted calix[4]arene derivatives 1a–5a had strong extraction ability towards mercury ion. The interaction of Hg2+with the calix ligand has also been investigated by 1H NMR titration.
Diastereoselective Epoxidation of N‐Enoylsultams with Different Chiral Sultams as Auxiliaries
Authors: Zhang Shu‐Jia , Chen Yong‐Kang , Li Hui‐Ming , Huang Wei‐Yang , Rogatchov Viktor , Metz Peter
Published: May 2006

Asymmetric epoxidation of N‐enoylsultams (1, 3–15) incorporating a variety of chiral sultams as the chiral induction elements with UHP/TFAA has been studied. Both diastereomeric isomers of epoxides (2, 16–28) were obtained in high yield and moderate to high optical purity.
Microwave‐promoted Beller Synthesis of N‐Substituted 2,3,3a,4,7,7a‐Hexahydroisoindole‐1,3‐diones
Authors: Da Chao‐Xi , Shou Wang‐Ge , Wang Yan‐Guang
Published: May 2006

A rapid and facile synthesis of N‐substituted 2,3,3a,4,7,7a‐hexahydroisoindole‐1,3‐dione derivatives via microwave‐promoted Beller three‐component domino reaction of α,β‐unsaturated aldehydes, amides and N‐substituted maleimides was described.
Hydrothermal Synthesis, Crystal Structure and Optical Properties of [M(en)3](ndt)·H2O (M=NiII, CoII, MnII and ndt=1,5‐Naphthalenedithiolate)
Authors: Yu Jing‐Hua , Wei Yong‐Ge , Ding Chang‐Jiang , Du Hong‐Guang , Yan Sheng‐Gang , Guo Hong‐You
Published: May 2006

Three novel compounds [Ni(en)3](ndt)·H2O (1), [Co(en)3](ndt)·H2O (2) and [Mn(en)3](ndt)·H2O (3) (en=ethylenediamine, ndt=1,5‐naphthalenedithiolate) have been synthesized under hydrothermal conditions. The structures were characterized by single crystal X‐ray diffraction and all belong to monoclinic space group Cc. The [M(en)3]2+ cations (M=NiII, CoII, MnII), ndt anions and crystallized water molecules assemble an iso‐structural three‐dimensional network through H‐bonding interactions. Optical absorption properties and band gaps of such three compouds were determined with UV/Vis/NIR diffuse reflectance spectra.
Conformational Transformation Exhibited by the Peptide Extracted from Crystalline Region of Bombyx mori Silk Fibroin in Solid and Solution States
Authors: Yao Ju‐Ming , Zhang Guo‐Qing , Lei Cai‐Hong
Published: May 2006

The conformational transformation of a 30‐residue peptide H(Ala‐Gly‐Ser‐Gly‐Ala‐Gly)5OH, i.e., (AGSGAG)5, extracted from highly crystalline region of Bombyx mori (B. mori) silk fibroin was described by using the high resolution solid state 13C NMR, and CD spectroscopies. Based on the conformation‐dependent 13C NMR chemical shifts of the Ala, Gly and Ser residues and the line‐shape analysis of the conformation sensitive Ala Cβ resonance, the peptide revealed a strong preference for silk II structural form, i.e., an antiparallel β‐sheet structure (ø=−140±20° and ψ=135±20°) in solid state. On the contrary, the CD spectra of this peptide in the two non‐native hexafluorinated fibre spinning solvents, hexafluoroisopropanol (HFIP) and hexafluoroacetone (HFA), exhibited the existence of an unusual tightly‐folded conformation resembling 310‐helix (ø=−60±20° and ψ=−30±20°), as judged from the R ratio of [θ]222/[θ]203 in HFIP solution, whereas a dynamically averaged unordered structure in HFA. Taken together, the information inclined to hypothesis that the primary structure of the highly crystalline regions of B. mori silk fibroin may be easily accessible to the large conformational changes, which in turn may be critical for facilitating the structural transformation from unprocessed silk fibroin (silk I form) to processed silk fiber (silk II form).
Optimization of an OFDM Rayleigh fading system
Authors: Varzakas P.
Published: May 2006

An OFDM cellular system operating in a Rayleigh fading environment is described and its spectral efficiency is estimated in terms of the theoretically achievable average channel capacity (in the Shannon sense) per user. The analysis covers the operation over a downlink cellular time‐varying link and leads to a simple novel closed‐form expression for the optimal number of individual OFDM subcarriers, based on the maximization of the achieved spectral efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Exact closed‐form symbol error rate of arbitrary rectangularM‐QAM over Rayleigh fading for two‐branch transmit diversity
Authors: Liu Hong‐Yu , Yen Rainfield Y.
Published: May 2006

By using a ‘pre‐averaging method’, we successfully derive an exact closed‐form symbol error rate (SER) expression for the particular case of two transmit‐one receive antenna diversity system employing arbitrary rectangularM‐QAM signalling over flat Rayleigh fading. Fading between branches are assumed independent. Both identical and distinct branch powers are considered. The closed‐form SER obtained is in terms of elemental functions containing no unevaluated integrals nor lengthy and complicated transcendental functions. Simulation results show that squareM‐QAM outperforms rectangularM‐QAM for a given sizeM. Monte Carlo simulation results are found in excellent agreements with theoretical results. Copyright © 2006 John Wiley & Sons, Ltd.