bluuebunny/crossref_metadata_2025 huggingface dataset:
Thiol–ene coupling reaction of fatty acid monomers
Authors: Samuelsson Johan , Jonsson Mats , Brinck Tore , Johansson Mats
Published: November 2004

The reactivities and reaction rates of the thiol–ene coupling reaction of 2‐ethyl‐(hydroxymethyl)‐1,3‐propanediol trimercapto acetate and 2‐ethyl‐(hydroxymethyl)‐1,3‐propanediol trimercapto propionate with two common unsaturated fatty acid methyl esters (methyl oleate and methyl linoleate) were evaluated. The reactions were monitored with real‐time IR and 1H NMR, which both showed that the mercapto acetate was more reactive than the mercapto propionate. Both thiols were more prone to add to the monounsaturated methyl oleate than to methyl linoleate, which contained two unconjugated double bonds. According to bond energy calculations, the thiol hydrogen of mercapto acetate was somewhat more difficult to abstract than the hydrogen of mercapto propionate. Consequently, the formed SC bond in the acetate case was stronger than in the propionate case, and so the equilibrium was more shifted toward the addition products. The real‐time IR measurements also showed that the cis unsaturation in methyl oleate isomerized much more quickly than that in methyl linoleate, and this also had an impact on the overall addition rate of the thiols because a trans unsaturation was more reactive than a cis unsaturation. The higher isomerization rates in the oleate systems, compared with those of the linoleate systems, was suggested to be due to a more restricted rotation along the CC bond of the reacted unsaturation in linoleate. This study showed the importance of trans unsaturations in obtaining reasonable reaction rates in thiol–ene reactions with fatty acid derivatives. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6346–6352, 2004
Preparation of calixarene‐containing polymer with proton transport ability
Authors: Wang Li , Shi Xianfa , Jia Pengjing , Yang Yong
Published: November 2004

To prepare calixarene‐based polymers with proton transport ability, the calix[4]arene derivatives with one polymerizable group at the upper rim were first prepared via selective nitration, amination, and acrylamidation of calix[4]arene. Two methods, solution polymerization and emulsion polymerization, were then employed to carry out the copolymerization of these derivatives with other monomers such as styrene, vinyl acetate, or methyl methacrylate. Transport experiments show that the resulting calixarene‐based polymers have a very good ability to transport protons. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6259–6266, 2004
Design and synthesis of optically transparent calcium‐incorporated polymer complexes
Authors: Sindhu S. , Valiyaveettil S.
Published: November 2004

Transparent thin films of calcium‐ion‐incorporated polymer composites were synthesized with calcium carbonate (CaCO3) and polymers such as poly(acrylic acid) (PAA), poly(ethylene glycol) (PEG), and methylcellulose. The homogeneous distribution of Ca2+ in the composite films was observed because of the high concentration of COO− groups along the PAA backbone for the complexation of Ca2+ ions. The optical transparency of the composites depends on the weight percentages of the three polymers and the molar concentration of CaCO3 in the composites. Maximum transparency was obtained for a composite film with a PAA/CaCO3 ratio of 9:1. The results indicated that methylcellulose improved the film‐forming capabilities and that PEG improved the transparency of the composites. All polymer complexes were characterized with X‐ray diffraction, fourier transfer infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, dynamic mechanical analysis, and optical transparency measurements. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4459–4465, 2004
ATCUN‐like metal‐binding motifs in proteins: Identification and characterization by crystal structure and sequence analysis
Authors: Sankararamakrishnan Ramasubbu , Verma Sandeep , Kumar Sandeep
Published: November 2004

The amino terminal Cu(II)‐ and Ni(II)‐binding (ATCUN) motif is a small metal‐binding site found in the N‐terminus of many naturally occurring proteins. The ATCUN motif has been implicated in DNA cleavage and has been shown to have antitumor activity. In proteins, the ATCUN motif is formed from a histidine in the third position, its preceding residue and the free N‐terminus. Four nitrogen atoms from these three residues act as metal ligands. Knowledge of metal‐binding geometry helps in the design of metal‐binding peptides and in understanding of the mechanisms of metal‐mediated functions. Since the N‐terminus region of ATCUN‐containing proteins is highly disordered, no geometrical features can be derived from the protein structures. However, the crystal structure of a small metal‐bound ATCUN peptide shows that the nitrogen ligands form a distorted square planar geometry. Distance constraints derived from this designed peptide were used to search 1949 polypeptide chains to find ATCUN‐like motifs in any position along the polypeptide chain. Only ≈1.9% and ≈0.3% of histidines are involved in partial and full ATCUN‐like geometric features, respectively. These two datasets were compared with the dataset of all histidines. None of the ATCUN‐like motifs occur in the middle of an α‐helix or a β‐strand. Further sequence analysis revealed total conservation of ATCUN histidines in four proteins including the transcription factor TBX3, implicated in Ulnar‐Mammary Syndrome. Our analysis suggests that the ATCUN‐like motif in TBX3 is a potential metal‐binding site, although a structural role was not completely ruled out. Metal‐binding activity in TBX3, if confirmed, will help us to understand the role of metals in transcriptional regulation and is likely to cast light on the causes of some serious genetic disorders. A conformational role is suggested for ATCUN‐like motifs in other proteins. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Distant replay: What can reinvestigation of a 40‐year‐old incident tell you? A look at Eastman Chemical's 1960 aniline plant explosion
Authors: Lodal Peter N.
Published: November 2004

On October 4, 1960, Eastman Chemical Company suffered the worst accident in its 83‐year history, when an aniline manufacturing facility exploded. Sixteen people were killed, and more than 300 injured, as a result of the blast. This paper analyzes the incident and its aftermath using both historical records and modern analytical techniques. The results provide useful insight into both the technical and cultural safety issues raised, as well as valuable information that can be applied to current processes. Careful analysis, even years after the fact, can reveal new information, as well as reinforce that which is already known. For example, the used of residue curve mapping techniques, combined with the ternary liquid–liquid phase diagram revealed a combination of circumstances that was not anticipated in 1960. As a result of this accident, Eastman instituted a Process Safety Review Committee structure that has continued to this day. One of the results of this structured approach has been an order‐of‐magnitude reduction in serious incidents, sustained over a four‐decade period. © 2004 American Institute of Chemical Engineers Process Saf Prog 23:221–228, 2004
An inherent safety–based incident investigation methodology
Authors: Goraya Attiq , Amyotte Paul R. , Khan Faisal I.
Published: November 2004

A methodology has been developed to enable the explicit use of the principles of inherent safety in an incident investigation protocol. The usefulness of this approach is demonstrated by application to the Westray coal mine explosion that occurred in Nova Scotia in 1992. This process‐related disaster resulted in the deaths of 26 workers, destruction of the underground workings, and bankruptcy of the parent company. The purpose in presenting this case study is twofold: to validate the methodology and to identify the inherent safety considerations that could have prevented the incident. These findings have application beyond the realm of coal mining, extending well into the world of the chemical process industries. © 2004 American Institute of Chemical Engineers Process Saf Prog 23:197–205, 2004
Fault tree and layer of protection hybrid risk analysis
Authors: Rothschild Marc
Published: November 2004

Layer of protection analysis (LOPA) is a relatively quick and straightforward method for quantifying risk. However, LOPA may be inadequate if used for compound failures when the required failure rate data are not available or when the failures are not independent. Fault tree analysis (FTA) can be used in these situations. FTA is designed to thoroughly and accurately evaluate compound failures and account for any dependencies between failures. FTA can augment LOPA, combining the best qualities of both methods into one powerful hybrid tool for risk analysis. © 2004 American Institute of Chemical Engineers (AIChE) Process Saf Prog 23:185‐190, 2004
An Improved R (Range) Control Chart for Monitoring the Process Variance
Authors: Khoo Michael B. C. , Lim E. G.
Published: November 2004

An R chart is often used to monitor shifts in the process variability. However, the range, $R_i, i = 1, 2, \dots$, statistics from a sampling distribution are highly skewed. Hence, the classical R chart based on the $\pm3\sigma$ control limits will not give an in‐control average run length of approximately 370, or equivalently a type I error, $\alpha = 0.0027$. In this paper, an approach is shown to obtain the control limits of an improved R chart based on a desired type I error from the density function of the Ri statistics. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling of Activity of Efavirenz with the Mutant of HIV Reverse Transcriptase using Variable Connectivity Indices
Authors: Zhong Chongli , He Jingtao , Xia Zhiqiang , Li Yajun
Published: November 2004

A model for estimation of activity for efavirenz analogues with the K 103N mutant of HIV‐1 RT was proposed in this work. The new model is predictive that requires only variable connectivity indices in the calculations. Compared with the existing models based on Monte Carlo simulation, the new model is easier to apply with better predictive accuracy, giving an r2of 0.85, cross‐validated Q2 of 0.82 and average error of only 0.23 kcal/mol for the 47 efavirenz analogues concerned. This work also demonstrates that variable connectivity indices, a class of not widely recognized structural descriptors, are quite useful in the QSAR studies in the fields of pharmaceutics and biochemistry. These topological indices may play a more important role in these fields in future.
Superconducting first‐order pairing: Finite‐temperature simulations
Authors: Böhm Michael C. , Schulte Joachim
Published: November 2004

A recently developed first‐order mechanism for superconducting pairing has been extended from T = 0 K to finite temperatures. On the basis of quantum statistical considerations, we have suggested a direct pairing interaction that does not necessarily involve second‐order elements, such as the electron–phonon coupling or specific magnetic interactions submitted by spin fluctuations. The driving force for the (energy‐driven) first‐order pairing is an attenuation of the destabilizing influence of the Pauli antisymmetry principle (PAP). Only the moves of unpaired fermions are controlled by the PAP, while the moves of superconducting Cooper pairs are not. The quantum statistics of Cooper pairs is of a mixed type, as it combines fermionic on‐site and bosonic intersite properties. The strong correlation between the strength of PAP constraints and system topology in combination with the electron number has been discussed for some larger clusters. Detailed finite‐temperature simulations on first‐order pairing have been performed for four‐center–four‐electron clusters with different topologies. A canonical ensemble statistics has been employed to derive the electronic energy, the electronic configuration entropy, and the free energy of paired and unpaired states in thermal equilibrium. The simulations show that pairing can be caused by either the electronic energy or the electronic configuration entropy. The coexistence of two different sets of quantum particles in paired states (i.e., the Cooper pairs and the unpaired electrons) can lead to an enhanced configuration entropy. In this context, we discuss the possibility of an entropy‐driven high‐temperature superconductor emerging from a low‐temperature unpaired state. The charge and spin degrees of freedom of the four‐center–four‐electron systems have been studied with the help of the charge and spin fluctuations. The spin fluctuations are helpful in judging the validity of pairing theories based on magnetic interactions. The charge fluctuations are a measure for the carrier delocalization in unpaired and paired states. The well‐known proximity between Jahn–Teller activity and superconductivity is analyzed in the zero‐temperature limit. It is demonstrated that both processes compete in their ability to reduce PAP constraints. All theoretical results have been derived within the framework of the simple Hubbard Hamiltonian. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical study of the unimolecular decomposition mechanisms of energetic TNAD and TNAZ explosives
Authors: Liu Min‐Hsien , Chen Cheng , Hong Yaw‐Shun
Published: November 2004

Calculation methods based on hybrid Density Functional Theory (DFT) with the basis sets of the B3LYP/6‐31+G(d)//B3LYP/4‐31G(d) method and the differential overlap (INDO) program were used to derive reasonable decomposition mechanisms of 1,4,5,8‐tetranitro‐1,4,5,8‐tetraazadecalin (TNAD) and 1,3,3‐trinitroazetidine (TNAZ) explosives. All possible decomposition species and transition states, including intermediates and products, were identified and their corresponding enthalpy of formation and Gibbs free energy of formation were obtained using polyparametric modification equations. INDO bond energy calculation results reveal the weakest bonding site for reference and determine where cleavage can occur easily. This work is concerned mainly with eliminating HONO (cis or trans form). The activation energy for trans‐form HONO elimination is lower than that of cis‐form HONO elimination in the initial steps of both TNAD and TNAZ decomposition, being 18.5 kJ/mol and 33.3 kJ/mol, respectively. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A sensitive, rapid and specific determination of midazolam in human plasma and saliva by liquid chromatography/electrospray mass spectrometry
Authors: Quintela Oscar , Cruz Angelines , Concheiro Marta , Castro Ana de , López‐Rivadulla Manuel
Published: November 2004

A rapid, sensitive and selective liquid chromatography/electrospray mass spectrometry (LC/ES‐MS) method was developed for the quantitative determination of the anaesthetic benzodiazepine midazolam (MID) in human saliva and plasma from patients undergoing anesthesia procedures. Biological samples spiked with diazepam‐d5, the internal standard, were extracted into diethyl ether. Compounds were separated on a Xterra® RP18 column using a mobile phase of acetonitrile/formic acid 0.1% at a flow rate of 0.25 mL/min under a linear gradient. Column effluents were analyzed using MS with an ES source in the positive ionization mode. Calibration curves were linear in the concentration ranges of 1–250 and 0.2–25 ng/mL in plasma and saliva, respectively. The limits of detection were 0.5 ng/mL in plasma and 0.1 ng/mL in saliva, using a 0.5‐mL sample volume. The recoveries of the spiked samples were above 65%. The method was applied to ten real samples from patients undergoing midazolam treatment. Copyright © 2004 John Wiley & Sons, Ltd.
Dynamics of river fish populations in response to hydrological conditions: a simulation study
Authors: Halls Ashley S. , Welcomme Robin L.
Published: November 2004

Increasing multi‐sectoral demands on water resources have led to water abstraction and transfer activities, and the construction of dams and embankments that have significantly altered the flood regimes of rivers throughout the world resulting in the loss of fish production and biodiversity. The current emphasis on sustainable development and biodiversity conservation is leading efforts to mitigate these impacts by means of interventions such as the release of artificial floods downstream of dams and the manipulation of water levels within impounded floodplains.

Whilst much work has been done to determine the hydrological requirements for the maintenance of salmonid populations, few equivalent studies are available from which to develop criteria for the management of hydrological regimes for fishes and fisheries in large floodplain–river systems such as the Mekong. The population dynamics of fish in such rivers are believed to respond to hydrological conditions in a density‐dependent manner. An age‐structured population dynamics model incorporating sub‐models describing density‐dependent growth, mortality and recruitment was used to explore how hydrological conditions within a theoretical floodplain–river system affect the dynamics of a common floodplain–river fish species.

Graphical summaries of the response of exploitable biomass to a range of different drawdown rates, dry and flood season areas and volumes, and flood season durations are presented under five different model assumptions concerning density‐dependent processes. Optimal flooding patterns are also described for the model species and theoretical river system.

The patterns of predictions that emerge from the simulations provide guidelines for managing or manipulating hydrological conditions in river systems for both fixed and variable volume hydrological scenarios. As a general rule of thumb, exploitable biomass is maximized by minimizing the rate of drawdown and maximizing the flood duration and flood and dry season areas or volumes. However, experiences from dam and other hydraulic engineering projects suggest that these predictions should be treated with caution until we better understand the influence of hydrology on spawning behaviour, system primary production, and critical habitat availability. Copyright © 2004 John Wiley & Sons, Ltd.
A Bayesian MCMC approach to study transmission of influenza: application to household longitudinal data
Authors: Cauchemez S. , Carrat F. , Viboud C. , Valleron A. J. , Boëlle P. Y.
Published: November 2004

We propose a transmission model to estimate the main characteristics of influenza transmission in households. The model details the risks of infection in the household and in the community at the individual scale. Heterogeneity among subjects is investigated considering both individual susceptibility and infectiousness. The model was applied to a data set consisting of the follow‐up of influenza symptoms in 334 households during 15 days after an index case visited a general practitioner with virologically confirmed influenza.

Estimating the parameters of the transmission model was challenging because a large part of the infectious process was not observed: only the dates when new cases were detected were observed. For each case, the data were augmented with the unobserved dates of the start and the end of the infectious period. The transmission model was included in a 3‐levels hierarchical structure: (i) the observation level ensured that the augmented data were consistent with the observed data, (ii) the transmission level described the underlying epidemic process, (iii) thepriorlevel specified the distribution of the parameters. From a Bayesian perspective, the jointposteriordistribution of model parameters and augmented data was explored by Markov chain Monte Carlo (MCMC) sampling.

The mean duration of influenza infectious period was estimated at 3.8 days (95 per cent credible interval, 95 per cent CI [3.1,4.6]) with a standard deviation of 2.0 days (95 per cent CI [1.1,2.8]). The instantaneous risk of influenza transmission between an infective and a susceptible within a household was found to decrease with the size of the household, and established at 0.32 person day−1(95 per cent CI [0.26,0.39]); the instantaneous risk of infection from the community was 0.0056day−1(95 per cent CI [0.0029,0.0087]). Focusing on the differences in transmission between children (less than 15 years old) and adults, we estimated that the former were more likely to transmit than adults (posteriorprobability larger than 99 per cent), but that the mean duration of the infectious period was similar in children (3.6 days, 95 per cent CI [2.3,5.2]) and adults (3.9 days, 95 per cent CI [3.2,4.9]). Theposteriorprobability that children had a larger community risk was 76 per cent and theposteriorprobability that they were more susceptible than adults was 79 per cent. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating trends and seasonality in coronary heart disease
Authors: Barnett A. G. , Dobson A. J. ,   For the WHO MONICA (monitoring trends and determinants in cardiovascular disease) Project
Published: November 2004

We present two methods of estimating the trend, seasonality and noise in time series of coronary heart disease events. In contrast to previous work we use a non‐linear trend, allow multiple seasonal components, and carefully examine the residuals from the fitted model. We show the importance of estimating these three aspects of the observed data to aid insight of the underlying process, although our major focus is on the seasonal components. For one method we allow the seasonal effects to vary over time and show how this helps the understanding of the association between coronary heart disease and varying temperature patterns. Copyright © 2004 John Wiley & Sons, Ltd.
Relation between Viscous Characteristics and Dextrose Equivalent of Maltodextrins
Authors: Dokic Ljubica , Jakovljevic Jovan , Dokic Petar
Published: November 2004

Relation between viscous characteristics of different maltodextrins and degree of starch hydrolytic conversion expressed as DE value (dextrose equivalent) was deduced.

Reduced viscosity of diluted solutions of maltodextrins linearly increased with maltodextrin concentration in the range 0.2×10−2 to 1×10−2 g/cm3. Values of intrinsic viscosity decreased with increasing degree of hydrolysis, which is expressed by DE values. Values of intrinsic viscosity of maltodextrins are independent of the botanical source of a particular starch but are dependent on molecular properties of samples that influence its friction characteristics in solution. When in diluted solutions, maltodextrins behave like macromolecules and obey the Staudinger‐Mark‐Houwink equation. Two ranges of DE value were established: DE = 0.5–10, in this range maltodextrin molecules in solution are randomly coiled (a = 0.53); and DE = 10–20, where the molecules are stretched (a = 1).

Equations for determination of DE value by viscometric measurements were derived for each of the two established DE ranges. DE values calculated from the equations show good agreement with the ones obtained by standard chemical titration methods.
Fluorinated polymers: liquid crystalline properties and applications in lithography
Authors: Krishnan Sitaraman , Kwark Young‐Je , Ober Christopher K.
Published: November 2004

Fluorinated polymers form an interesting class of materials with a wealth of unique properties including self‐assembly, remarkably low surface energies, low absorbance to 157 nm UV light, and solubility in supercritical carbon dioxide. As a result many fluorinated polymers are of use in advanced technology applications. We review some of our work on the synthesis and characterization of block copolymers with fluorinated side chains, with special emphasis on surfaces formed using these polymers. The use of fluorinated polymers as photoresists for 157 nm lithography, with the possibility for processing in environmentally friendly supercritical carbon dioxide is also discussed. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 315–330; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20022
An external PIXE study: Mughal painting pigments
Authors: Reiche I. , Britzke R. , Bukalis G. , Reinholz U. , Weise H.‐P. , Gadebusch R. D.
Published: November 2004

Recently, a new external beam PIXE facility was installed at the 2 MV tandem ion accelerator of the Federal Institute for Materials Research and Testing (BAM). For external beam PIXE, 1–3 MeV protons are extracted through a thin exit window and focused on the target under air pressure. This set‐up is particularly suitable for multielement trace analysis in the field of unique art and archaeological objects. We report the first archaeometric findings of the study of Mughal painting pigments by means of this experimental set‐up. The Indian miniatures chosen for the study date from the Mughal period (1526–1858) and were executed by various artists in particular workshops between the 17th and the 19th centuries. The paintings are typical depictions of Mughal sovereigns and courtiers or show genre scenes. Until now, in contrast to European paintings, only scarce information on the materials used in the workshops of Mughal painters has been available. Therefore, the exact knowledge of the painting materials employed would allow a more detailed attribution of the precious miniatures to a particular period and to distinguish original paintings from later copies. Copyright © 2004 John Wiley & Sons, Ltd.
Hyperphosphorylation of extracellular regulated kinase 2 (ERK2) and inhibition of JNK2 phosphorylation are associated with increased S‐phase during transformation of Syrian hamster embryo cells by Malachite Green
Authors: Bose Bipasha , Gour Rekha R. , Motiwale Leena , Gupta Sanjay , Rao K.V.K.
Published: November 2004

Malachite Green (MG), consisting of green crystals with a metallic lustre, is highly soluble in water, cytotoxic to various mammalian cells and also acts as a liver tumour promoter. In view of its industrial importance and possible exposure to human beings, MG poses a potential environmental health hazard. We have earlier reported the malignant transformation of Syrian hamster embryo (SHE) cells in primary culture by MG. In this study, we have studied the mitogen activated protein (MAP) kinase signal transduction pathway in preneoplastic cells induced by MG. Western blots of MG induced preneoplastic cells showed no phosphorylation of ERK1, an increased phosphoactive ERK2 associated with a decreased expression of phosphoactive JNK2. However, total forms of ERKs, JNKs and p38 Kinases showed similar levels of expression in control and preneoplastic SHE cells. Indirect immunofluorescence studies have shown a distinct nuclear localisation of phosphoactive ERKs in MG induced preneoplastic cells. Flow cytometric analysis showed an increase of S‐phase cells in preneoplastic cells compared to control SHE cells. The present study indicates that hyperphosphorylation of ERK2, decreased JNK2 phosphorylation and an increase in S‐phase cells seems to be the early changes associated with the MG induced malignant transformation of SHE cells in primary culture.
Betablockers in heart failure: Carvedilol Safety Assessment (CASA 2‐trial)
Authors: Rickli Hans , Steiner Simon , Müller Karin , Hess Otto M.
Published: November 2004

Background:

Betablockers are a cornerstone in the treatment of patients with chronic heart failure (CHF). The purpose of the present study was to assess safety and tolerability of carvedilol in CHF‐patients.

Methods:

66 general practitioners, who were supervised by a local cardiologist, enrolled 151 CHF‐patients. All patients were on standard therapy with ACE‐inhibitors and diuretics. Carvedilol treatment was started with 3.125 mg twice daily and slowly uptitrated in 2‐week intervals to 2×25 mg per day. Mean follow‐up was 12 weeks.

Results:

145 of the 151 patients (96%) finished the study according to protocol, six patients were lost to follow‐up (4%). 59 patients (41%) experienced minor and nine (6%) serious adverse events. 68 were under maximal therapy with 50 mg daily, 33 received 25 mg, and 15 12.5 mg. Overall tolerability was good and NYHA‐class fell significantly from 2.2 to 1.8 (P<0.001). Mean heart rate decreased from 78 to 69 bpm (P<0.001), mean systolic blood pressure from 137 to 132 mmHg (P<0.001) and mean diastolic blood pressure from 80 to 76 mmHg (P<0.001). Quality of life significantly improved under carvedilol with a reduction in the Minnesota living with heart failure score from 1.28 to 0.88 (P<0.001).

Conclusions:

Carvedilol is well tolerated in CHF‐patients treated by general practitioners. Serious adverse events and hospitalisations are rare. Thus, carvedilol is a safe drug in the treatment of CHF‐patients and can be easily initiated and managed by the general practitioner.
Acupuncture for the relief of cancer‐related pain — a systematic review
Authors: Lee Hyangsook , Schmidt Katja , Ernst Edzard
Published: November 2004

Aims This systematic review summarises the existing evidence on acupuncture for cancer‐related pain.

Methods Literature searches were conducted in seven databases. All clinical studies of acupuncture, electroacupuncture and ear acupuncture in cancer patients with the main outcome measure of pain were included. Data were extracted according to pre‐defined criteria by two independent reviewers and methodological quality was assessed using the Jadad scale.

Results Of the seven studies included, one high quality randomised clinical trial of ear acupuncture showed statistically significant pain relief in comparison with placebo ear acupuncture. All the other studies were either non‐blinded (n = 2) or uncontrolled clinical trials (n = 4). Most investigations suffered from methodological flaws such as inadequate study design, poor reporting of results, small sample size and overestimation of the results.

Conclusions The notion that acupuncture may be an effective analgesic adjunctive method for cancer patients is not supported by the data currently available from the majority of rigorous clinical trials. Because of its widespread acceptance, appropriately powered RCTs are needed.
Uncoupling of GPCR and RhoA‐induced Ca2+‐sensitization of chicken amnion smooth muscle lacking CPI‐17
Authors: Stevenson Andrá S. , Matthew John D. , Eto Masumi , Luo Shizhen , Somlyo Andrew P. , Somlyo Avril V.
Published: November 2004

Ca2+‐sensitization of smooth muscle occurs through inhibition of myosin light chain phosphatase (MLCP) leading to an increase in the MLCK:MLCP activity ratio. MLCP is inhibited through phosphorylation of its regulatory subunit (MYPT‐1) following activation of the RhoA/Rho kinase (ROK) pathway or through phosphorylation of the PP1c inhibitory protein, CPI‐17, by PKC δ or ROK. Here, we explore the crosstalk between these two modes of MLCP inhibition in a smooth muscle of a natural CPI‐17 knockout, chicken amnion. GTPγS elicited Ca2+‐sensitized force which was relaxed by GDI or Y‐27632, however, U46619, carbachol and phorbol ester failed to induce Ca2+‐sensitized force, but were rescued by recombinant CPI‐17, and were sensitive to Y‐27632 inhibition. In the presence, but not absence, of CPI‐17, U46619 also significantly increased GTP · RhoA. There was no affect on MYPT‐1 phosphorylation at T695, however, T850 phosphorylation increased in response to GTPγS stimulation. Together, these data suggest a role for CPI‐17 upstream of RhoA activation possibly through activation of another PP1 family member targeted by CPI‐17.
Heterozygosity in CTLA‐4 gene and severe preeclampsia
Authors: Samsami Dehaghani A. , Doroudchi M. , Kalantari T. , Pezeshki A.M. , Ghaderi A.
Published: November 2004

Objective

One of the major complications of pregnancy, preeclampsia makes pregnancy termination inevitable in most cases. Similarities exist between the mechanisms that maintain normal pregnancy, allograft transplants, and, it is postulated, peripheral self‐tolerance. In addition, the critical role of the cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) molecule in maintaining self‐tolerance has been established. Therefore, the frequency of CTLA‐4 A49G polymorphism was investigated in severe preeclampsia.

Patients and Methods

Genomic DNA extracted from mononuclear cells of the peripheral blood of 36 pregnant women with severe preeclampsia and 151 healthy women was analyzed. A49G polymorphism in position 49 of exon‐1 of the CTLA‐4 gene was studied by the polymerase chain reaction–single‐strand conformation polymorphism (PCR–SSCP) method.

Results

The frequency of the GG genotype was 2 (5.6%) in patients and 19 (12.6%) in controls, while the frequency of the AA genotype was 4 (11.1%) and 60 (39.7%). Interestingly, the frequency of the AG genotype was significantly higher in preeclamptic than in healthy women from the general population (83.3% vs. 47.7%; P=0.0005).

Conclusion

These data suggest that heterozygosity in the CTLA‐4 A49G allele might be a predisposing factor for severe preeclampsia. Whether the observed association results from linkage imbalance with other loci on chromosome 2 or other polymorphisms of the CTLA‐4 gene or even from a preferential transfer and/or expression of one allele from a heterozygous mother to the fetus will be the subject of future investigations.
Quality management and organizational context in selected service industries of China
Authors: Zhao Xiande , Yeung Andy C.L. , Lee T.S.
Published: November 2004

By developing an empirical taxonomy of quality management systems (QMS) in selected service industries in China, we compare the taxonomy of QMS developed in the service industries to that found in previous studies in manufacturing industries. We further investigate contingency relationships between the development of a QMS and its organizational contexts. Based on cluster analyses of quality management practices measured by the Malcolm Baldrige National Quality Award (MBNQA) criteria, we found four patterns of service quality management practices: undeveloped, accommodating, strategic, and soft quality systems. Our research indicates that the type of quality system adopted by an organization is highly associated with organizational contextual factors. Our results indicate that environmental uncertainty shapes the development of a QMS in the early stage, while the perceived importance of quality induces the further development of a QMS to a strategic quality system. The results also show that small service firms that compete locally can achieve very good performance results using a soft quality system, a QMS with no formal process management systems. This research provides empirical evidence on contingent relationships among quality management practices, organizational context, and business performance, thus contributing to contingency theory in quality management.
Polyethylene and titanium particles induce osteolysis by similar, lymphocyte‐independent, mechanisms
Authors: Taki Naoya , Tatro Joscelyn M. , Nalepka Jennifer L. , Togawa Daisuke , Goldberg Victor M. , Rimnac Clare M. , Greenfield Edward M.
Published: November 2004

Periprosthetic osteolysis is a major clinical problem that limits the long‐term survival of total joint arthroplasties. Osteolysis is induced by implant‐derived wear particles, primarily from the polyethylene bearing surfaces. This study examined two hypotheses. First, that similar mechanisms are responsible for osteolysis induced by polyethylene and titanium particles. Second, that lymphocytes do not play a major role in particle‐induced osteolysis. To test these hypotheses, we used the murine calvarial model that we have previously used to examine titanium‐induced osteolysis. Polyethylene particles rapidly induced osteolysis in the murine calvaria 5–7 days after implantation. The polyethylene‐induced osteolysis was associated with large numbers of osteoclasts as well as the formation of a thick periosteal fibrous tissue layer with numerous macrophages containing phagocytosed polyethylene particles. Polyethylene‐induced osteolysis was rapidly repaired and was undetectable by day 21 after implantation. Lymphocytes were noted in the fibrous layer of wild‐type mice. However, the amount of osteolysis and cytokine production induced by polyethylene particles was not substantially affected by the lack of lymphocytes in Pfp/Rag2 double knock out mice. All of these findings are similar to our observations of osteolysis induced by titanium particles. These results provide strong support for both of our hypotheses: that similar mechanisms are responsible for osteolysis induced by polyethylene and titanium particles and that lymphocytes do not play a major role in particle‐induced osteolysis. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Dissolved organic nitrogen dominates in European bogs under increasing atmospheric N deposition
Authors: Bragazza Luca , Limpens Juul
Published: November 2004

To assess the effects of increased atmospheric N input on N availability in ombrotrophic peatlands, the relative concentrations of dissolved organic nitrogen (DON) to dissolved inorganic nitrogen (DIN) were measured in bog waters along a natural gradient of atmospheric N deposition. Six European bogs were selected, spanning a range of chronic atmospheric N inputs from 0.2 to 2.0 g m−2 yr−1. DIN as well as DON concentrations increased with N deposition, the latter increasing at a sharper incline. The increase in DIN concentrations was related to the reduced capacity of the moss layer to trap atmospheric N, which in turn was a result of N saturation of the moss layer. The enhanced DON concentrations appear to be a consequence of increased leaching of organic N compounds by Sphagnum. The importance of DON on N biogeochemistry in bogs opens new perspectives in relation to nutrient limitation and organic matter turnover.
Physical response of mid‐ocean ridge hydrothermal systems to local earthquakes
Authors: Wilcock William S. D.
Published: November 2004

Observations from the East Pacific Rise (EPR) and the Endeavour segment of the Juan de Fuca Ridge show that local earthquake swarms can lead to increased hydrothermal venting temperatures after a delay of several days. I develop two models for this process. In the temperature perturbation model, a new pathway opens to a heat source, and the temperatures of fluids leaving the reaction zone increase. By considering the exchange of heat between the fluid flowing up a conduit and the wall rock, I solve for the resulting perturbation to venting temperatures. For flow in a crack the response is delayed, and the delay increases as the crack narrows or the reaction zone deepens, but for a pipe the venting temperature increases either quickly or barely at all. In the pressure perturbation model, there is a transient increase in pressures at depth due to a decrease in porosity, the release of overpressured fluids, or a readjustment of pressures in response to a change in the relative permeabilities of the upflow and downflow zones. One‐dimensional solutions for pressure diffusion show that this model can lead to a delayed increase in outflow fluxes which may be accompanied by increased venting temperatures. The temperature perturbation model fits the data from the EPR event well. The Endeavour event is less well constrained, and both models can fit the observations adequately. Local seismic networks and time series of fluid flux, chemistry, and temperature will be required to fully exploit hydrothermal perturbation events to infer subseafloor hydrology.
Insight into Mt. Etna (Italy) kinematics during the 2002–2003 eruption as inferred from seismic stress and strain tensors
Authors: Barberi G. , Cocina O. , Maiolino V. , Musumeci C. , Privitera E.
Published: November 2004

Seismic activity linked to the 2002–03 Mt. Etna eruption was investigated by analyzing the Md > 2.3 earthquakes. The results of 3D relocation were used to compute fault plane solutions and a selected dataset was inverted to determine stress and strain tensors. The analysis revealed a complex kinematic response of the eastern flank dominated by fast stress propagation and reorientation. We hypothesize that a vertical dike intruded the southern flank, generating an extensional regime that triggered a radial intrusion in the northeast sector of the volcano. The combined effects gave rise to a rotation of the stress tensor that controlled the activation of the Pernicana fault system. The volcanic and tectonic interactions produced a second reorientation of the stress tensor, causing a structural response in the southeast lower flank. The overall result of the deformation processes observed during the eruption was an E‐W extension on the eastern flank of the volcano.
Numerical considerations of fluid effects on wave propagation: Influence of the tortuosity
Authors: Saenger E. H. , Krüger O. S. , Shapiro S. A.
Published: November 2004

The focus of this paper is on effective elastic properties (i.e., velocities) in three different kinds of dry and fluid‐saturated porous media. The synthetic results are compared with the predictions of the Gassmann equation and the tortuosity‐dependent high‐frequency limit of the Biot velocity relations. Using a dynamic finite‐difference approach we observe for Fontainebleau sandstone the same effective elastic properties as with a static finite‐element approach. We show that so‐called open‐cell Gaussian random field models are similar in mechanical properties to Fontainebleau sandstone. For all synthetic models considered in this study the high‐frequency limit of the Biot velocity relations is very close to the predictions of the Gassmann equation. However, using synthetic rock‐models saturated with an imaginary fluid of high density we can approximately estimate the corresponding tortuosity parameter.
Asymptotic quasinormal frequencies for black holes in nonasymptotically flat space–times
Authors: Cardoso Vitor , Natário José , Schiappa Ricardo
Published: November 2004

The exact computation of asymptotic quasinormal frequencies is a technical problem which involves the analytic continuation of a Schrödinger-type equation to the complex plane and then performing a method of monodromy matching at several poles in the plane. While this method was successfully used in asymptotically flat space–time, as applied to both the Schwarzschild and Reissner–Nordstro/m solutions, its extension to nonasymptotically flat space–times has not been achieved yet. In this work it is shown how to extend the method to this case, with the explicit analysis of Schwarzschild–de Sitter and large Schwarzschild–anti–de Sitter black holes, both in four dimensions. We obtain, for the first time, analytic expressions for the asymptotic quasinormal frequencies of these black hole space–times, and our results match previous numerical calculations with great accuracy. We also list some results concerning the general classification of asymptotic quasinormal frequencies in d-dimensional space–times.
Public-key encryption with chaos
Authors: Kocarev Ljupco , Sterjev Marjan , Fekete Attila , Vattay Gabor
Published: November 2004

We propose public-key encryption algorithms based on chaotic maps, which are generalization of well-known and commercially used algorithms: Rivest–Shamir–Adleman (RSA), ElGamal, and Rabin. For the case of generalized RSA algorithm we discuss in detail its software implementation and properties. We show that our algorithm is as secure as RSA algorithm.
Mechanotransduction and strain amplification in osteocyte cell processes
Authors: Han Yuefeng , Cowin Stephen C. , Schaffler Mitchell B. , Weinbaum Sheldon
Published: November 2004

A paradox in bone tissue is that tissue-level strains due to animal and human locomotion are too small to initiate intracellular chemical responses directly. A model recently was proposed to resolve this paradox, which predicts that the fluid flow through the pericellular matrix in the lacunar-canalicular porosity due to mechanical loading can induce strains in the actin filament bundles of the cytoskeleton that are more than an order of magnitude larger than tissue level strains. In this study, we greatly refine this model by using the latest ultrastructural data for the cell process cytoskeleton, the tethering elements that attach the process to the canalicular wall and their finite flexural rigidityEI. We construct a much more realistic 3D model for the osteocyte process and then use large-deformation “elastica” theory for finiteEIto predict the deformed shape of the tethering elements and the hoop strain on the central actin bundle. Our model predicts a cell process that is 3 times stiffer than in a previous study but hoop strain of >0.5% for tissue-level strains of >1,000 microstrain at 1 Hz and >250 microstrain at frequencies >10 Hz. We propose that this strain-amplification model provides a more likely hypothesis for the excitation of osteocytes than the previously proposed fluid-shear hypothesis.
An improved algorithm for stoichiometric network analysis: theory and applications
Authors: Urbanczik R. , Wagner C.
Published: November 2004

Motivation: Genome scale analysis of the metabolic network of a microorganism is a major challenge in bioinformatics. The combinatorial explosion, which occurs during the construction of elementary fluxes (non-redundant pathways) requires sophisticated and efficient algorithms to tackle the problem.

Results: Mathematically, the calculation of elementary fluxes amounts to characterizing the space of solutions to a mixed system of linear equalities, given by the stoichiometry matrix, and linear inequalities, arising from the irreversibility of some or all of the reactions in the network. Previous approaches to this problem have iteratively solved for the equalities while satisfying the inequalities throughout the process. In an extension of previous work, here we consider the complementary approach and derive an algorithm which satisfies the inequalities one by one while staying in the space of solution of the equality constraints. Benchmarks on different subnetworks of the central carbon metabolism of Escherichia coli show that this new approach yields a significant reduction in the execution time of the calculation. This reduction arises since the odds that an intermediate elementary flux already fulfills an additional inequality are larger than when having to satisfy an additional equality constraint.

Availability: The code is available upon request.

Supplementary information: Pseudo code and a Mathematica implementation of the algorithm is on the OUP server.

Contact:  robert.urbanczik@pki.unibe.ch; clemens.wagner@pki.unibe.ch
Primaclade—a flexible tool to find conserved PCR primers across multiple species
Authors: Gadberry Michael D. , Malcomber Simon T. , Doust Andrew N. , Kellogg Elizabeth A.
Published: November 2004

Summary: Primaclade is a web-based application that accepts a multiple species nucleotide alignment file as input and identifies a set of polymerase chain reaction (PCR) primers that will bind across the alignment. Primaclade iteratively runs the Primer3 application for each alignment sequence and collates the results. Primaclade creates an HTML results page that recaps the original alignment, provides a consensus sequence and lists primers for each alignment area, with primers color-coded to reflect the level of degeneracy in the primer.

Availability: Primaclade can be accessed freely at http://www.umsl.edu/~biology/Kellogg/primaclade.html

Contact:  tkellogg@umsl.edu