bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereoselective Hydrogenation of Olefins Using Rhodium‐Substituted Carbonic Anhydrase—A New Reductase
Authors: Jing Qing , Okrasa Krzysztof , Kazlauskas Romas J.
Published: December 2008

One useful synthetic reaction missing from nature's toolbox is the direct hydrogenation of substrates using hydrogen. Instead nature uses cofactors like NADH to reduce organic substrates, which adds complexity and cost to these reductions. To create an enzyme that can directly reduce organic substrates with hydrogen, researchers have combined metal hydrogenation catalysts with proteins. One approach is an indirect link where a ligand is linked to a protein and the metal binds to the ligand. Another approach is direct linking of the metal to protein, but nonspecific binding of the metal limits this approach. Herein, we report a direct hydrogenation of olefins catalyzed by rhodium(I) bound to carbonic anhydrase (CA‐[Rh]). We minimized nonspecific binding of rhodium by replacing histidine residues on the protein surface using site‐directed mutagenesis or by chemically modifying the histidine residues. Hydrogenation catalyzed by CA‐[Rh] is slightly slower than for uncomplexed rhodium(I), but the protein environment induces stereoselectivity favoring cis‐ over trans‐stilbene by about 20:1. This enzyme is the first cofactor‐independent reductase that reduces organic molecules using hydrogen. This catalyst is a good starting point to create variants with tailored reactivity and selectivity. This strategy to insert transition metals in the active site of metalloenzymes opens opportunities to a wider range of enzyme‐catalyzed reactions.
Bright, Color‐Tunable Fluorescent Dyes in the Vis/NIR Region: Establishment of New “Tailor‐Made” Multicolor Fluorophores Based on Borondipyrromethene
Authors: Umezawa Keitaro , Matsui Akihiro , Nakamura Yuki , Citterio Daniel , Suzuki Koji
Published: December 2008

A new series of high‐performance fluorophores named Keio Fluors (KFL), which are based on borondipyrromethene (BODIPY), are reported. The KFL dyes cover a wide spectral range from the yellow (547 nm) to the near‐infrared (NIR, 738 nm) region, and their emission wavelength could be easily and subtly controlled based on simple molecular modifications only, without losing their optical properties. This “tailor‐made” synthetic strategy for tuning the emission wavelength enabled the creation of fourteen KFL dyes with well‐controlled emission colors (yellow, orange, red, far‐red, and NIR). Moreover, these KFL dyes also retain their excellent optical properties, such as spectral bands sharper than quantum dots, high extinction coefficients (140 000–316 000 M−1 cm−1), and high quantum yields (0.56–0.98), without any critical solvent polarity dependent decrease of their brightness. These advantageous characteristics make the KFL dyes potentially useful as new candidates of fluorescent standard dyes to substitute or to complement existing long‐wavelength fluorescent dyes, such as cyanines, oxazines, rhodamines, or other BODIPY dyes.
Effect of shaft eccentricity on the laminar mixing performance of a radial impeller
Authors: Cabaret F. , Fradette L. , Tanguy P.A.
Published: December 2008

The effects of impeller eccentricity and Reynolds number on the mixing performance were studied for Rushton turbine stirred tank systems operated in the laminar regime (Re < 10). A digital image analysis of an acid–base decolourization reaction was used to characterize the mixing efficiency. Results show that both parameters have remarkable effects on the destruction of the toroidal segregated regions surrounding the Rushton turbine in laminar flow. Criteria are given to prevent the formation of these segregated regions in a tank. It is also shown that shaft eccentricity does not impact on the impeller power consumption.
Synthesis of heterogeneous copper complex catalyst for oxidation of cyclohexane using molecular oxygen
Authors: Anisia K.S. , Kumar A.
Published: December 2008

Binuclear macrocyclic copper complex was synthesized and bonded ionically to the montmorillonite clay to enhance thermal stability upto 600°C. The oxidation of cyclohexane using molecular oxygen in the absence of initiators, promoters and coreactants has been studied in the temperature range 145–190°C. The overall cyclohexane conversion was 21% at 180°C and cyclohexanone, the major product with 71% selectivity. The experimental data were analyzed against kinetic scheme proposed and the rate constants determined using Genetic Algorithm.
Notes on the issues of equilibrium in the Fischer–Tropsch synthesis
Authors: Norval Graeme W.
Published: December 2008

The product distribution for the Fischer–Tropsch synthesis is normally described using the kinetically derived (Anderson–Schultz–Flory) ASF model. Variations of the kinetic model have been proposed to explain deviations from the ASF distribution. The Fischer–Tropsch system can be equally well described using a pseudo‐element (CH2, H2, O) equilibrium approach. A one‐parameter equilibrium model is derived for the product distributions for alkenes, alkanes and alcohols.

The Fischer–Tropsch system should be considered as three separate partial equilibria systems: the product homologous series; the water gas shift system, and the redox behaviour of the catalyst with the H2/O ratio of the gas. This approach correctly predicts the impacts of changes in a variety of parameters (temperature pressure, feed composition) on the ASF product distribution. In addition, the catalyst phase changes with gas composition and pressure, indicative of an equilibrium response. Equilibrium is of much greater importance to the Fischer–Tropsch system than previously thought, and the decision to use a complex kinetics‐based model rather than a simpler equilibrium based model should be taken with care.
Henry's law constant for hydrogen in high temperature water with dissolved lithium and boron
Authors: Giraudeau Franck , Lister Derek H. , Morris David R. , Setthanan Uncharat , Steward Frank R. , Yang Lei Tai
Published: December 2008

The results of measurement of the Henry's law constant are reported for solutions of H2 in H2O, with dissolved lithium and boron, at high temperature (220 to ∼300°C). The experimental procedure involved the use of a palladium/hydrogen electrical resistance sensor to determine the hydrogen gas pressure in equilibrium with the hydrogen dissolved in the water. Values of $K_{\rm H}^\infty$ for the above solutions were lower than values for the solute‐free H2/H2O solutions. For conditions typical of a Pressurized Water Reactor (PWR) the lowering amounted to about 3%.
Catalytic dehydration of lactic acid to acrylic acid over sulfate catalysts
Authors: Zhang Jinfeng , Lin Jianping , Cen Peilin
Published: December 2008

The production of acrylates from biomass‐originated lactic acid is of extraordinary importance to overcome the increasing worldwide shortage of petroleum. In this work, the catalytic dehydration of lactic acid to acrylic acid was carried out over calcium sulfate catalyst with cupric sulfate and phosphates as promoters. The mass ratio of m(CaSO4)/m(CuSO4)/m(Na2HPO4)/m(KH2PO4) is 150.0:13.8:2.5:1.2. In the dehydration of lactic acid, effects of carrier gas, calcination temperature for catalyst, concentration of lactic acid as well as contact time are discussed in detail. With carbon dioxide as carrier gas, the highest acrylic acid yield of 63.7% is achieved from 26 wt.% lactic acid at 330°C and 88 s contact time.
Measurement of sliding velocity and induction time of a single micro‐bubble under an inclined collector surface
Authors: Najafi Aref Seyyed , Xu Zhenghe , Masliyah Jacob
Published: December 2008

In this study, interactions between a gas bubble and a flat solid surface were investigated by determining two dynamic parameters, bubble sliding velocity underneath an inclined solid surface and induction time of the gas bubble attaching to the solid surface in aqueous solutions. A single micro‐bubble was allowed to move vertically toward an inclined solid surface. After reaching its terminal velocity, the bubble approaches the inclined solid surface and slides underneath it. Complete trajectory of the bubble movement was monitored and recorded by a high‐speed CCD video imaging system.

Various types of gas bubbles (CO2, air, H2, and O2) and solid surfaces such as bitumen‐coated Teflon, hydrophobized and hydrophilic silica were used in sliding velocity and induction time measurements. The effect of water chemistry (industrial process water and de‐ionized water) and surface heterogeneity on bubble sliding velocity and induction time was investigated. The results showed that the sliding velocity of micro‐bubbles under an inclined solid surface is a strong function of water chemistry, gas type, temperature and hydrophobicity of the solid surface. This study provides relevant information on bubble–solid interactions that would assist in the understanding of bubble–solid attachment under diverse conditions.
Steam fingering at the edge of a steam chamber in a heavy oil reservoir
Authors: Gotawala Dharmesh R. , Gates Ian D.
Published: December 2008

The steam‐assisted gravity drainage (SAGD) process is one of the key in situ recovery processes being used today to recover heavy oil and bitumen. In this process, steam injected through a horizontal well, flows convectively towards the outer edges of a depletion chamber. At the edges of the depletion chamber, the steam releases its latent heat to the cool oil sand and raises its temperature. The heated oil is mobile and flows under the action of gravity to a horizontal production well located several metres below the injection well. It remains unclear what is the exact mechanism of chamber growth. Some have suggested that in addition to heat conduction, it is by convective steam flow in the form of pointed fingers at the edges of the chamber which penetrate the oil sand. In theory published by Butler [Butler, J. Can. Petroleum Technol. 1987;26(3):70–75], it was determined that the fingers can be as long as 6 m for Athabasca bitumen reservoirs. In this research, a new theory is derived and provides predictions of the rise rate which compare better to estimates derived from field thermocouple data and physical model experimental observations than values obtained from Butler's theory. The results suggest that in the absence of mobile water, heat conduction rather than steam fingers at the chamber edge is the dominant heat transfer mechanism.
Twenty‐four‐month postradiation prostate biopsies are strongly predictive of 7‐year disease‐free survival
Authors: Crook Juanita M. , Malone Shawn , Perry Gad , Eapen Libni , Owen Julie , Robertson Susan , Ludgate Charles , Fung Sharon , Lockwood Gina
Published: December 2008

BACKGROUND:

The objective of this study was to evaluate the predictive value of prostate biopsies that were obtained 24 months after the completion of radiotherapy (RT) with respect to disease‐free survival (DFS) in a randomized trial that compared 3 months versus 8 months of neoadjuvant hormone therapy before conventional dose external RT.

METHODS:

From February 1995 to June 2001, 378 men were randomized to receive either 3 months or 8 months of combined flutamide and goserelin before they received 66 Gray of RT at 4 participating centers. By risk group, 26% of patients were categorized as low risk, 43% were categorized as intermediate risk, and 31% were categorized as high risk. The 2 treatment arms were balanced in terms of age, Gleason score, clinical tumor classification, risk group, and presenting prostate‐specific antigen level. The median follow‐up for the patients who remained alive was 6.6 years (range, 1.6‐10.1 years). Of 361 evaluable patients, 290 patients remained alive. Post‐RT prostate biopsies were performed between 24 and 30 months after the completion of RT in 3 of the 4 centers. Biopsies that had residual tumor with severe treatment effect were considered indeterminate, and biopsies that had minimal or no treatment effect were considered positive.

RESULTS:

The 5‐year rate of actuarial freedom from any failure for the 3‐month arm versus the 8‐month arm was 72% versus 75% (P = .18). The DFS for patients who had negative and indeterminate biopsies was similar. Two‐year post‐treatment biopsy status was a strong predictor of 5‐year DFS rate (82% and 83% for negative and indeterminate biopsies, respectively, vs 27% for positive biopsies; P < .0001). Multivariate analysis indicated that biopsy status (P < .0001) and Gleason score (P < .0001) were the strongest determinates of biochemical DFS.

CONCLUSIONS:

Two‐year post‐RT prostate biopsies were strongly predictive of subsequent DFS. Biopsies with severe treatment effect were considered negative. Cancer 2009. © 2008 American Cancer Society.
Prevention of postoperative hypocalcemia with routine oral calcium and vitamin D supplements in patients with differentiated papillary thyroid carcinoma undergoing total thyroidectomy plus central neck dissection
Authors: Roh Jong‐Lyel , Park Jae‐Yong , Park Chan‐Il
Published: December 2008

BACKGROUND:

Routine oral calcium and vitamin D supplementation may prevent hypocalcemic crisis, but its efficacy has not been studied in patients undergoing thyroidectomy plus central neck dissection (CND). The authors therefore prospectively evaluated the clinical usefulness of routine oral calcium and vitamin D supplementation for prevention of hypocalcemia after total thyroidectomy and CND.

METHODS:

Of 197 patients with differentiated papillary thyroid carcinoma, 49 underwent total thyroidectomy alone, and 148 underwent total thyroidectomy plus CND. The latter were randomized to oral calcium (3 g/day) plus vitamin D (1 mg/day) (Group A, n = 49), calcium alone (Group B, n = 49), or no supplements (Group C, n = 50). Hypocalcemic symptoms, serum calcium, and parathyroid hormone (PTH) levels were compared among the groups.

RESULTS:

Group C had significantly higher incidences of symptomatic (26.0% vs 6.1%; P < .015) and laboratory (44.0% vs 14.3%; P < .015) hypocalcemia than the group without CND. The incidences of symptomatic and laboratory hypocalcemia were significantly decreased in Groups A (2.0% and 8.2%, respectively) and B (12.2% and 24.5%, respectively) (P < .05). Serum calcium levels decreased in most patients after surgery, but recovered earliest in Group A. Hypercalcemia and PTH inhibition did not occur in gs A and B.

CONCLUSIONS:

Compared with total thyroidectomy alone, CND significantly increases the rate of postoperative hypocalcemia, which can be prevented by routine postoperative supplementation with oral calcium and vitamin D. Cancer 2009. © 2009 American Cancer Society.
Benign breast lesions at risk of developing cancer—A challenging problem in breast cancer screening programs
Authors: Manfrin Erminia , Mariotto Renata , Remo Andrea , Reghellin Daniela , Falsirollo Francesca , Dalfior Daniela , Bricolo Paola , Piazzola Elena , Bonetti Franco
Published: December 2008

BACKGROUND:

Cytology and core‐needle biopsies are not always sufficient to exclude malignancy in benign breast lesions (BBL) that are at risk of developing cancer, and open biopsy often is mandatory. In screening programs, open biopsies performed for lesions that are at risk of developing malignancy are considered benign. The authors of this report evaluated the impact of the screen‐detected BBL at risk of developing cancer that were counted in the quota of benign breast open biopsies in the Breast Cancer Screening Program of Verona.

METHODS:

Benign open biopsies were subdivided into 4 groups according to their risk of developing cancer: Histo1, normal histology; Histo2, ‘pure’ BBL (fibroadenoma, fibrocystic disease, mastitis, adenosis); Histo3, BBL with a low risk of developing cancer (radial scar, papilloma, papillomatosis, phyllodes tumor, mucocele‐like lesion); and Histo4, BBL with a high risk of developing cancer (atypical columnar cell hyperplasia, atypical ductal hyperplasia, atypical lobular hyperplasia).

RESULTS:

Of 510 open biopsies, 83 biopsies were benign, and the ratio of benign to malignant biopsies was 1:5. Histo1 was observed in 4.8% of all benign open biopsies, Histo2 was observed in 37.4%, Histo3 was observed in 31.3%, and Histo4 was observed 26.5%.

CONCLUSIONS:

BBL at risk of developing cancer may be numerous in screening programs. It is inappropriate to include BBL at risk of developing cancer in the overall benign open biopsy rate. The authors propose separating pure BBL from lesions at higher risk of developing cancer. To date, there is no evidence to support the premise that detecting high‐risk proliferative lesions leads to benefits in terms of reduced mortality; however, these lesions need to be counted separately for future evaluations. Cancer 2009. © 2008 American Cancer Society.
Projection method with self‐adaptive time steps for LES of ignition and extinction in non‐premixed jet flames
Authors: Liu Yi , Chen Yongqiang , Kulasegaram Sivakumar
Published: December 2008

In this paper, a modified projection method is combined with a self‐adaptive time step procedure to develop numerical scheme for large eddy simulation (LES) of low Ma number turbulent reactive flows. The projection method introduced by Chorin is modified in this study to satisfy the simulation requirement of low Ma number reactive flow. The time step in this computation is automatically determined according to the time scales of both chemical reaction and turbulent fluctuations. This enables the simulation to capture detailed flow structures with less computational time. Numerical simulation of methane–air jet flames is carried out as an example to validate the developed numerical scheme. The mechanism of a simplified 4‐step chemical kinetics is applied for the methane–air reaction. The dynamic model is adopted for the turbulent motion of sub‐grid scale (SGS). The dynamic similarity model is used as the SGS model for the reaction rate. The LES results satisfactorily depict the ignition process of the turbulent jet flames and illustrate lucid and detailed coherent structures of the fully developed turbulent reactive jet flow. The LES results also exhibit the mechanism and characteristics of local extinction. The method developed in this study provides an effective way to capture more flow details with less computational time. In addition the method also helps one to investigate the mechanism of ignition and local extinction in jet flames. Copyright © 2008 John Wiley & Sons, Ltd.
Triple‐Resonance Coherent Anti‐Stokes Raman Scattering Microspectroscopy
Authors: Min Wei , Lu Sijia , Holtom Gary R. , Xie X. Sunney
Published: December 2008

Fluorescence‐free microscopy: A new nonlinear optical microspectroscopy technique, femtosecond (fs) triple‐resonance coherent anti‐Stokes Raman scattering, in which the amplitude and phase of input fs laser pulses are optimally shaped to be in triple resonance with the molecular electronic and vibrational transitions, generates a coherent nonlinear signal beam at a new color with a highest possible efficiency (see figure).

magnified image
Critical Size for O2 Dissociation by Au Nanoparticles
Authors: Roldán Alberto , González Silvia , Ricart Josep Manel , Illas Francesc
Published: December 2008

Density functional theory calculations predict that the presence of low‐coordination Au atoms is not enough to dissociate O2, that there is a common pathway for O2 dissociation on Au nanoparticles and that there is critical size for Au nanoparticles to dissociate O2 (see figure).

magnified image

Density functional theory calculations carried out for a series of Au nanoparticles as well as for extended systems containing low‐coordinated sites show that the presence of low‐coordinate Au atoms is not enough to dissociate O2. Strong adsorption of molecular oxygen on Au nanoparticles is a necessary but not sufficient condition for O2 dissociation, there is a common pathway for O2 dissociation on these nanoparticles and there is critical size for Au nanoparticles to dissociate O2.
The Influence of Charge Transport and Recombination on the Performance of Dye‐Sensitized Solar Cells
Authors: Wang Mingkui , Chen Peter , Humphry‐Baker Robin , Zakeeruddin Shaik M. , Grätzel Michael
Published: December 2008

Electrochemical impedance spectroscopy (EIS) and transient voltage decay measurements are applied to compare the performance of dye sensitized solar cells (DSCs) using organic electrolytes, ionic liquids and organic‐hole conductors as hole transport materials (HTM). Nano‐crystalline titania films sensitized by the same heteroleptic ruthenium complex NaRu(4‐carboxylic acid‐4′‐carboxylate) (4,4′‐dinonyl‐2,2′‐bipyridyl)(NCS)2 , coded Z‐907Na are employed as working electrodes. The influence of the nature of the HTM on the photovoltaic figures of merit, that is, the open circuit voltage, short circuit photocurrent and fill factor is evaluated. In order to derive the electron lifetime, as well as the electron diffusion coefficient and charge collection efficiency, EIS measurements are performed in the dark and under illumination corresponding to realistic photovoltaic operating conditions of these mesoscopic solar cells. A theoretical model is established to interpret the frequency response off the impedance under open circuit conditions, which is conceptually similar to photovoltage transient decay measurements. Important information on factors that govern the dynamics of electron transport within the nanocrystalline TiO2 film and charge recombination across the dye sensitized heterojunction is obtained.
Scaled MP3 Non‐Covalent Interaction Energies Agree Closely with Accurate CCSD(T) Benchmark Data
Authors: Pitoňák Michal , Neogrády Pavel , Černý Jiří , Grimme Stefan , Hobza Pavel
Published: December 2008

Scaled MP3 interaction energies calculated as a sum of MP2/CBS (complete basis set limit) interaction energies and scaled third‐order energy contributions obtained in small or medium size basis sets agree very closely with the estimated CCSD(T)/CBS interaction energies for the 22 H‐bonded, dispersion‐controlled and mixed non‐covalent complexes from the S22 data set. Performance of this so‐called MP2.5 (third‐order scaling factor of 0.5) method has also been tested for 33 nucleic acid base pairs and two stacked conformers of porphine dimer. In all the test cases, performance of the MP2.5 method was shown to be superior to the scaled spin‐component MP2 based methods, e.g. SCS–MP2, SCSN–MP2 and SCS(MI)–MP2. In particular, a very balanced treatment of hydrogen‐bonded compared to stacked complexes is achieved with MP2.5. The main advantage of the approach is that it employs only a single empirical parameter and is thus biased by two rigorously defined, asymptotically correct ab‐initio methods, MP2 and MP3. The method is proposed as an accurate but computationally feasible alternative to CCSD(T) for the computation of the properties of various kinds of non‐covalently bound systems.
Physicochemical Characterization of Subporphyrazines—Lower Subphthalocyanine Homologues
Authors: Rahman G. M. Aminur , Lüders Daniela , Rodríguez‐Morgade M. Salomé , Caballero Esmeralda , Torres Tomás , Guldi Dirk M.
Published: December 2008

The periphery is central: The luminescent properties of boron(III) subporphyrazines are strongly influenced by their peripheral functionalization. These photoactive materials generate long‐lived triplet excited states that mediate the sensitized production of singlet oxygen. Furthermore, their ability to behave either as oxidizing or reducing chromophores is promising for their application in molecular photovoltaics.

magnified image

Physicochemical characterization of boron(III) subporphyrazines (SubPzs)—lower subphthalocyanine (SubPc) homologues—has been carried out for the first time. The SubPz macrocycle can act both as an oxidizing and a reducing entity, giving rise to stable radical anion or radical cation species, respectively. SubPzs are luminescent and exhibit fluorescence quantum yields that are in the range known for SubPcs. The peripheral substitution plays a dramatic role with respect to the luminescence properties. Moreover, as with SubPcs, deactivation of the singlet excited state of the SubPzs by intersystem crossing affords long‐lived triplet excited states, which are amenable to being used as singlet‐oxygen generators. Subporphyrazines are also promising electro‐ and photoactive materials for molecular photovoltaics.
Sustainable Synthesis of Aldehydes, Ketones or Acids from Neat Alcohols Using Nitrogen Dioxide Gas, and Related Reactions
Authors: Naimi‐Jamal M. Reza , Hamzeali Hamideh , Mokhtari Javad , Boy Jürgen , Kaupp Gerd
Published: December 2008

Benzylic alcohols are quantitatively oxidized by gaseous nitrogen dioxide to give pure aromatic aldehydes. The reaction gas mixtures are transformed to nitric acid, which renders the processes free of waste. The exothermic gas–liquid or gas–solid reactions profit from the solubility of nitrogen dioxide in the neat benzylic alcohols. The acid formed impedes further oxidation of the benzaldehydes. The neat isolated benzaldehydes and nitrogen dioxide quantitatively give the benzoic acids. Solid long‐chain primary alcohols are directly and quantitatively oxidized with nitrogen dioxide gas to give the fatty acids in the solid state. The oxidations with ubiquitous nitrogen dioxide are extended to solid heterocyclic thioamides, which gives disulfides, and to diphenylamine, which gives tetraphenylhydrazine. These sustainable (green) specific oxidation procedures produce no dangerous residues from the oxidizing agent or from auxiliaries.
An uplink resource allocation scheme for OFDMA‐based cognitive radio networks
Authors: Wang Wei , Wang Wenbo , Lu Qianxi , Peng Tao
Published: December 2008

Cognitive radio makes it possible for an unlicensed user to access a spectrum unoccupied by licensed users. In cognitive radio networks, extra constraints on interference temperature need to be introduced into radio resource allocation. In this paper, the uplink radio resource allocation is investigated for OFDMA‐based cognitive radio networks. In consideration of the characteristics of cognitive radio and OFDMA, an improved water‐filling power allocation scheme is proposed under the interference temperature constraints for optimal performance. Based on the improved water‐filling power allocation, a simple subcarrier allocation algorithm for uplink is proposed. The subcarrier allocation rules are obtained by theoretical deduction. In the uplink subcarrier allocation algorithm, the subcarriers are allocated to the users with the best channel quality initially and then adjusted to improve the system performance. A cursory water‐filling level estimation method is used to decrease the complexity of the algorithm. Asymptotic performance analysis gives a lower bound of the stability of the water‐filling level estimation. The complexity and performance of the proposed radio resource allocation scheme are investigated by theoretical analysis and numerical results. Copyright © 2008 John Wiley & Sons, Ltd.
Application‐layer community‐oriented uplink scheduler for CDMA networks
Authors: Demestichas Konstantinos P. , Adamopoulou Evgenia F. , Theologou Michael E.
Published: December 2008

This paper focuses on community‐based mobile applications and delivers an efficient application‐layer uplink scheduler for the collection of community responses in CDMA networks, capable of pursuing the best possible compromise between delay and radio resource constraints. The scheduling problem is mathematically formulated and solved, based on a novel probabilistic approach inspired by the birthday paradox. Results of the proposed approach are presented and analyzed. Copyright © 2008 John Wiley & Sons, Ltd.
Neuerungen bei den Baustoffen in DIN 1053‐11 und ‐13
Authors: Brameshuber Wolfgang , Schmidt Ulf , Graubohm Markus
Published: December 2008

Der aktuelle Bearbeitungsentwurf von DIN 1053 enthält eine Reihe von Neuerungen in Bezug auf die Baustoffe, die Bemessung sowie Ausführung und Konstruktion. Die nderungen und Neuerungen bei den Baustoffen sowie deren Festigkeits‐ und Verformungseigenschaften, die entsprechend dem aktuellen Entwurfsstatus der Normen DIN 1053‐11 (Vereinfachtes Nachweisverfahren für unbewehrtes Mauerwerk) und DIN 1053‐13 (Genaueres Nachweisverfahren für unbewehrtes Mauerwerk) Berücksichtigung finden sollen, werden in diesem Beitrag vorgestellt und erläutert.
A detailed investigation of maternally inherited diabetes and deafness (MIDD) including clinical characteristics, C‐peptide secretion, HLA‐DR and ‐DQ status and autoantibody pattern
Authors: Hosszúfalusi Nóra , Karcagi Veronika , Horváth Rita , Palik Éva , Várkonyi Judit , Rajczy Katalin , Prohászka Zoltán , Szentirmai Csaba , Karádi István , Romics László , Pánczél Pál
Published: December 2008

Background This article presents a clinically characterization of the mitochondrial DNA mutation (A3243G) associated with maternally inherited diabetes and deafness (MIDD) syndrome in two families.

Methods Six patients with MIDD and one mutation‐positive relative with normal glucose tolerance (NGT) were examined. Fasting serum C‐peptide was measured in all subjects and compared with controls having NGT (n = 14). C‐peptide response to an intravenous glucose tolerance test (IVGTT) was investigated in the diabetic patients not treated with insulin (n = 3) and in the mutation‐positive healthy individual and compared with the controls.

Results The A3243G heteroplasmy value varied between 5 and 30%. All A3243G carriers had HLA‐DR1‐DQ5 haplotype, and either the ‐DQ5 or the ‐DQ6 allele. The fasting and the serum C‐peptide levels at 120 min during the IVGTT did not differ between the A3243G carriers and the controls. A missing first phase and a decreased total C‐peptide response was detected in the mutation‐positive diabetics compared with controls (p < 0.0001). The same abnormality was found in the A3243G carrier with NGT. Circulating islet cell antibody (ICA) was present in three patients with MIDD. Glutamic acid decarboxylase (GAD), tyrosine phosphatase‐like protein IA‐2 (IA‐2) and mitochondrial antibodies were missing. The diagnosis of MIDD was delayed in each case.

Conclusions A missing first phase and a decreased total C‐peptide response during an IVGTT was characteristic for the A3243G mutation. The fasting C‐peptide level of the carriers did not differ from the controls. Circulating ICA was present in some patients, but GAD, IA‐2 and mitochondrial antibodies were absent. All subjects had HLA‐DR1‐DQ5 haplotype, and either ‐DQ5 or ‐DQ6 alleles. Copyright © 2008 John Wiley & Sons, Ltd.
Emotional perception in eating disorders
Authors: Joos Andreas A.B. , Cabrillac Emmanuelle , Hartmann Armin , Wirsching Michael , Zeeck Almut
Published: December 2008

Objective:

It remains an open question whether there are basic emotional perception and emotional processing deficits in eating disorders (ED). The aim of this study was to explore deficits in emotional perception in restrictive anorexia nervosa (AN‐R) and bulimia nervosa (BN), using visual emotional stimuli.

Method:

Thirty‐four patients with ED (19 with BN and 15 with AN‐R) were compared with 25 controls. Visual stimuli from the international affective picture system were used.

Results:

Patients with AN‐R showed increased fear when confronted with stimuli containing anger, whereas patients with BN showed a tendency towards decreased fear. There were no other fundamental differences in the emotional perception of fear, happiness, sadness, and anger.

Discussion:

The finding of increased fear when exposed to the emotion of anger might be attributed to introversion and conflict avoidance of anorectic patients. No other basic deficiency of emotional perception was found. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord, 2009
Dysfunctional schemas and eating pathology in overweight youth: A case–control study
Authors: Van Vlierberghe Leen , Braet Caroline , Goossens Lien
Published: December 2008

Objective:

This study aimed to investigate in overweight adolescents the association of dysfunctional schemas (negative basic beliefs about the self and one's relationships with others) on one hand and eating disorder (ED) symptoms and depression on the other hand.

Method:

Participants were 32 overweight adolescents experiencing loss of control over eating (LC) and 32 overweight youngsters experiencing no loss of control over eating (NoLC), matched on referral status, age, gender, and degree of overweight. Adolescents were interviewed with the Eating Disorder Examination—Child version and completed the Young Schema Questionnaire and the Children's Depression Inventory.

Results:

The LC group displayed a greater severity of dysfunctional schemas than the NoLC group. Maladaptive schemas were related to ED cognitions, dietary restraint attitudes, and depressive symptoms.

Discussion:

In overweight youngsters, ED symptoms are associated with dysfunctional thinking patterns and negative affect. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord, 2009
Anorexia Nervosa: Beyond boundaries
Authors: Qadan Laila
Published: December 2008

Objective

To describe Anorexia Nervosa in a patient from the Middle‐East where this condition is believed to be rare.

Method

The diagnosis of Anorexia Nervosa was based on detailed history and physical examination, and was in accordance with DSM‐IV diagnostic criteria.

Discussion

Anorexia Nervosa should not be overlooked in Middle‐Eastern cultures. Local values may play an important role in the management of the disease. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord, 2009
Statistical analysis of nitrate concentrations from the Rivers Frome and Piddle (Dorset, UK) for the period 1965–2007
Authors: Howden N. J. K. , Burt T. P.
Published: December 2008

The results presented here update those of Casey and Clarke (Freshwater Biology, 1979), ecologists who studied nitrate concentrations in the River Frome in southern England from 1965 to 1976, finding that average annual nitrate concentrations were increasing at the rate of around 0·11 mg NO3N l−1 year−1. Statistical analyses at the same East Stoke site for the period 1978 to 2003 are presented and results are compared with the neighbouring River Piddle for the period 1978 to 2007 which, unlike the Frome, lies entirely within the Chalk in its upper reaches. The method of Casey and Clarke (1979) is followed in applying general linear and nonlinear estimation models (NEMs) to explore the sources of variation in the nitrate concentration data. The proportions of the total variation in nitrate concentration attributable to differences between years and to differences between months are similar for the Frome in both periods. For the Frome and Piddle models from 1978 onwards, an even greater proportion of variation is explained by differences between years rather than differences between months, suggesting that long‐term change is the dominant effect. Analyses of annual mean nitrate concentration data show a sustained linear trend over the study period for both rivers and indicate that the rate of increase of annual mean nitrate concentration continues at a rate not significantly different from that found by Casey and Clarke (1979). Four versions of a NEM were applied, including the original Casey and Clarke (1979) model. The inclusion of flow variables adds little to the overall explanation and a cosine index remains the most effective descriptor of seasonal variations in nitrate concentration, suggesting seasonal in‐stream biological uptake as a dominant control, rather than hydrological catchment response. Copyright © 2008 John Wiley & Sons, Ltd.
Electronic Spectra of Mono‐ and Dinuclear Complexes of Fully π‐Conjugated salphen Ligands Synthesized by Using 2,6‐Dihydroxynaphthalene Carbaldehydes
Authors: Houjou Hirohiko , Motoyama Takatoshi , Araki Koji
Published: December 2008

A series of mono‐ and dinuclear zinc(II), copper(II), nickel(II), and iron(III) complexes of novel salphen ligands were synthesized and spectroscopically characterized. The mononuclear ligand (H2L1) was synthesized from 2,6‐dihydroxynaphthalene‐1‐carbaldehyde and an o‐phenylenediamine; the dinuclear ligand (H4L2), which was not isolated, contains a 2,6‐dihydroxynaphthalene‐1,5‐dicarbaldimine linkage that enables extended π‐conjugation over two salphen units. Bymeans of a controlled sequence of condensation reactions, the constituents were built into either mono‐ ([ML1]) or dinuclear complexes ([M2L2]). The UV/Vis spectra of the [M2L2] complexes exhibited absorbances that were approximately twice as intense as those of the [ML1] complexes, as well as a 30–50‐nm bathochromic shift and considerable extension of the low‐energy absorption edge relative to the spectrum of [ML1]. The spectra of the complexes showed markedly intensified peaks in various regions, depending on M, which implies that the effects of extension of π‐conjugation were due to more than simple additivity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Application of MALDI‐TOF mass spectrometry in lipidomics
Authors: Fuchs Beate , Schiller Jürgen
Published: December 2008

Lipids are of high interest on different levels. First, lipids as triacylglycerols (TAG) (particularly different vegetable oils) are of immense commercial interest. Second, lipids are of high relevance for different in vivo processes. For instance, the diagnostics of changes of the lipoproteins of human blood is very important in vascular diseases, whereas phospholipids (PL) are crucial for the properties of the cellular membrane and some selected PL were also recognized to represent important second messengers. Although there are many different methods (including different chromatographic and spectroscopic approaches) available, mass spectrometry (MS) is the most versatile tool of lipid analysis, with or without prior separation steps. Although several different ionization techniques are capable of producing ions from the lipids of interest, matrix‐assisted laser desorption and ionization time‐of‐flight (MALDI‐TOF) MS is the simplest and most convenient method. This review gives a short methodological survey of the capabilities and drawbacks of MALDI‐TOF MS and discusses its role in lipidomic studies. Although a summary about PL analysis will also be given, the focus of this review is the analysis of apolar lipids as TAG, cholesterol and cholesteryl esters. Aspects of sample preparations and the avoidance of pitfalls are also highlighted. Finally, it is the aim of this paper to show that MALDI MS provides data comparable to other modern MS methods, but in a faster and more convenient way.
Lipidomic methodologies applicable to the study of endocannabinoids and related compounds: Endocannabinoidomics
Authors: Bisogno Tiziana , Piscitelli Fabiana , Di Marzo Vincenzo
Published: December 2008

The identification of the endogenous ligands of the cannabinoid CB1and CB2receptors (endocannabinoids) as lipids nominally derived from arachidonic acid was a further demonstration that lipid molecules can be endowed with important signaling functions. This discovery was paralleled by the development of ever more sophisticated technologies for the profiling of small molecules, and the subsequent birth and exponential growth of the discipline of “metabolomics” and, in the case of analytical techniques for lipids, of its subdiscipline known as “lipidomics”. The application of lipidomics to the analysis of endocannabinoids, and of endocannabinoid‐like molecules with activities also at non‐cannabinoid receptors, is now culminating in the identification of more families of fatty acid derivatives, thus revealing what has been defined as the “endocannabinoid metabolome”, and in the development of specific techniques for the lipidomic profiling of these molecules. These new analytical advances are discussed in this article.
A Facile and Efficient Oxalyldihydrazide/Ketone‐Promoted Copper‐Catalyzed Amination of Aryl Halides in Water
Authors: Zhu Xinhai , Su Li , Huang Liye , Chen Gong , Wang Jinlong , Song Huacan , Wan Yiqian
Published: December 2008

A novel three‐component catalyst CuO/oxalyldihydrazide/hexane‐2,5‐dione was a very convenient, economic, and effective catalytic system for the Ullmann‐type C–N coupling reaction in water. Both aryl bromides and aryl iodides could be aminated by a variety of amines even at room temperature or with heating to afford very good isolated yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Highly Diastereo‐ and Enantioselective Aldol Reactions in Common Organic Solvents Using N‐Arylprolinamides as Organocatalysts with Enhanced Acidity
Authors: Moorthy Jarugu Narasimha , Saha Satyajit
Published: December 2008

A broad set of N‐arylprolinamides 1–8 with increasing NH acidity and steric crowding has been synthesized and its catalytic activity explored for enantioselective aldol reactions. In DMF containing 10 mol‐% of TFA, all arylamides are found to catalyze the reaction between cyclohexanone and a variety of electrophilic aldehydes leading to aldols in excess of 90 % yield and >95 % enantioselectivity. The perfluorophenyl catalyst 8 is found to perform best with a broad substrate scope as compared to all other N‐arylamides 1–7. It is shown that 8 can indeed be employed in highly nonpolar as well as polar solvents including brine to afford high yields of aldols with excellent diastereo‐ as well as enantioselectivity. The results observed for 8 are amongst the best reported so far for prolinamides that do not contain additional stereogenic center(s) and hydrogen‐bonding site(s). The molecular structures of 7 and 8, determined by X‐ray crystallography and presumed to reflect the most stable conformations, reveal a notable difference in the conformations of the N‐aryl rings; the aryl ring exhibits tendency to lie coplanar with the amide functionality in the case of 7, while the perfluorophenyl ring twists almost orthogonally with respect to the plane of the amide of functionality in 8. The superior performance of the latter is attributed to, in addition to the enhanced NH acidity, the tendency of the perfluorophenyl ring to lie orthogonally to the amide group, which may facilitate a stronger binding of the electrophilic aldehyde via hydrogen bonding in the transition state.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Stereoselectivity of Glycosylation May Change During the Reaction Course: Highly α‐Stereoselective Sialylation Achieved by Supramer Approach
Authors: Kononov Leonid O. , Malysheva Nelly N. , Orlova Anna V.
Published: December 2008

The stereoselectivity of NIS/TfOH‐promoted glycosylation with O‐acetylated N‐acetylneuraminic acid phenyl thioglycoside was found to be dependent on the reaction time. Highly α‐stereoselective sialylation (27:1 anomer ratio) was achieved by decreasing the reaction time (from 3 h to 15 min) and by adding a non‐reacting compound (1 equiv.) capable of modifying the structure of hydrogen‐bonded supramolecular aggregates (supramers) of the glycosyl donor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
The role of floodplains in attenuating contaminated sediment fluxes in formerly mined drainage basins
Authors: Dennis Ian A. , Coulthard Tom J. , Brewer Paul , Macklin Mark G.
Published: December 2008

Many upland river catchments in the UK have been historically mined for metals such as lead (Pb) and zinc (Zn), and as part of the mining process large quantities of metal contaminated sediment were released into the river system. The levels of sediment associated heavy metal contamination in river systems are largely controlled by the volumes of contaminated sediment released into the river and fluvial processes (e.g. erosion and deposition). As a consequence, the contamination patterns are often highly variable, which can make it difficult to create accurate assessments of the volumes of contaminated sediment remaining within the system. This paper uses a combination of techniques to establish the volumes of metal contaminated sediment remaining within the River Swale, UK. Firstly, using detailed field sampling and a geographical information system (GIS), it estimates the volumes of sediment remaining within one formerly mined tributary (Gunnerside Beck) which is then extrapolated to represent the contaminant volumes on other tributaries of the River Swale. Secondly, combining fresh field data with a range of existing data, volumes of contaminated sediment on the main stream of the River Swale are established. This two tier approach shows that significant volumes of contaminated sediment remain within the River Swale, with over 32 000 tonnes of Pb within the mined tributaries and 123 000 tonnes within the main channel belt of the River Swale itself. This represents approximately 28% of the Pb produced in the Swale catchment. Given these volumes and present day rates of removal, it may take over 5000 years for all of the metal rich sediment to be removed from the catchment. If the contaminated sediment is used as a tracer, present day rates of reworking of floodplain sediment can be calculated to be 0·02% per year. Copyright © 2008 John Wiley & Sons, Ltd.
Transmission reservation and transactions modeling in electricity markets
Authors: Hao Shangyou , Shirmohammadi Dariush
Published: January 2009

Significant progresses have been made in developing analytical models for electricity markets to schedule and price supply and demand resources. However, transmission‐specific service products such as bilateral energy transactions, transmission capacity reservations, and transmission rights transactions have been left largely as the by‐product of market development. For instance, a bilateral transaction across multiple interconnected systems is normally preconditioned on acquiring transmission capacity reservation in market or non‐market systems. To be economically efficient, such a transaction should be considered simultaneously with the aggregated use from all market participants in order to price the true transmission costs. In most of today's electricity markets, it is difficult for market participants to directly schedule an economic transmission capacity reservation, or an economic purchase of transmission rights from markets.

This paper presents a new optimization formulation for forward electricity markets, extending traditional market capabilities from the scheduling and pricing of energy resources to the scheduling of economic transmission transactions and transmission capacity reservation by considering the economic costs of transmission. Examples are provided to illustrate the applications and features of the proposed model. The proposed model helps markets improve the utilization of transmission. It may also be used to manage cross‐border transactions of market and non‐market systems reducing seams between them. Copyright © 2008 John Wiley & Sons, Ltd.
An improved leader progression model for the analysis of the shielding performance of 1000 kV UHVAC transmission lines
Authors: Wei Bengang , Fu Zhengcai , Yuan Haiyan , Du Patrick Y.
Published: December 2008

This paper presents an improved leader progression model (LPM). The model uses the proposed leader inception criterion for the analysis of lightning shielding performance of UHVAC transmission lines. It focuses on the discussion of the leader inception voltage of bundle conductors. The improved LPM is validated on 500 kV EHV transmission lines. The shielding performance of a UHVAC transmission line to be constructed in a Chinese Test Line Project is then evaluated. The results indicate that the power frequency operating voltage and the bundle conductor configuration have a greater influence on the shielding failure flashover rate (SFFOR) of 1000 kV UHV lines than that of 500 kV EHV lines. It is found that the UHVAC line to be built will not cause trip accidents due to shielding failure in flat terrain. In broken terrain, the SFFOR is only 0.0012 times/100 km·year, which is less than the design limit. Copyright © 2008 John Wiley & Sons, Ltd.