bluuebunny/crossref_metadata_2025 huggingface dataset:
Number-average size model for geological systems and its application in economic geology
Authors: Wang Q. F. , Wan L. , Zhang Y. , Zhao J. , Liu H.
Published: July 2011

Abstract. Various natural objects follow a number-size relationship in the fractal domain. In such relationship, the accumulative number of the objects beyond a given size shows a power-law relationship with the size. Yet in most cases, we also need to know the relationship between the accumulative number of the objects and their average size. A generalized number-size model and a number-average size model are constructed in this paper. In the number-average size model, the accumulative number shows a power-law relationship with the average size when the given size is much less than the maximum size of the objects. When the fractal dimension Ds of the number-size model is smaller than 1, the fractal dimension Ds of the number-average size model is almost equal to 1; and when Ds > 1, the Dm is approximately equal to Ds. In mineral deposits, according to the number-average size model, the ore tonnage may show a fractal relationship with the grade, as the cutoff changes for a single ore deposit. This is demonstrated by a study of the relationship between tonnage and grade in the Reshuitang epithermal hot-spring gold deposit, China.
Detector Design and Complexity Analysis for Cooperative Communications in Intersymbol Interference Fading Channels
Authors: Peng Yanjie , Klein Andrew G. , Huang Xinming
Published: July 2011

The area of cooperative communications has recently attracted lots of research interest because of the potential benefit of increased spatial diversity. In this paper, we study the detector design for cooperative communications in intersymbol interference (ISI) channels. A novel system framework employing nonorthogonal amplify-and-forward half-duplex relays through ISI channels is introduced. We focus on detector design and first consider an optimal detector that consists of a whitening filter and a maximum-likelihood sequence estimator (MLSE). However, such an optimal detector embedded with Viterbi algorithm has practical issues of high complexity if the relay period is long. Consequently, we adopt a multitrellis Viterbi algorithm (MVA) that reduces the complexity significantly but still achieves near-optimal performance. Simulation results demonstrate the performance of both the optimal and near-optimal detector designs.
Arthroscopic Treatment of Stiff Elbow
Authors: Blonna Davide , Bellato Enrico , Marini Eleonora , Scelsi Michele , Castoldi Filippo
Published: July 2011

Contracture of the elbow represents a disabling condition that can impair a person's quality of life. Regardless of the event that causes an elbow contracture, the conservative or surgical treatment is usually considered technically difficult and associated with complications. When the conservative treatment fails to restore an acceptable range of motion in the elbow, open techniques have been shown to be successful options. More recently the use of arthroscopy has become more popular for several reasons. These reasons include better visualization of intra-articular structures, less tissue trauma from open incisions, and potentially the ability to begin early postoperative motion. The purpose of this paper is to review the indications, complications, and results of arthroscopic management of a stiff elbow.
Pathway Profiling and Rational Trial Design for Studies in Advanced Stage Cervical Carcinoma: A Review and a Perspective
Authors: Scholl Susy M. E. , Kenter Gemma , Kurzeder Christian , Beuzeboc Philippe
Published: July 2011

Multiple genetic abnormalities will have occurred in advanced cervical cancer and multiple targeting is likely to be needed to control tumor growth. To date, dominant therapeutic targets under scrutiny for cervical cancer treatment have been EGFR pathway and angiogenesis inhibition as well as anti-HPV vaccines. The potentially most effective targets to be blocked may be downstream from the membrane receptor or at the level of the nucleus. Alterations of the pathways involved in DNA repair and in checkpoint activations, as well as the specific site of HPV genome integration, appear worth assessing. For genetic mutational analysis, complete exon sequencing may become the norm in the future but at this stage frequent mutations (that matter) can be verified by PCR analysis. A precise documentation of relevant alterations of a large spectrum of protein biomarkers can be carried out by reverse phase protein array (RPPA) or by multiplex analysis. Clinical decision-making on the drug(s) of choice as a function of the biological alteration will need input from bio-informatics platforms as well as novel statistical designs. Endpoints are yet to be defined such as the loss (or reappearance) of a predictive biomarker. Single or dual targeting needs to be explored first in relevant preclinical animal and in xenograft models prior to clinical deployment.
Exponential Stability and Guaranteed Cost of Switched Linear
Systems with Mixed Time-Varying Delays
Authors: Tissir El Houssaine
Published: July 2011

This paper deals with the problems of exponential stability and guaranteed cost of switched linear systems with mixed time delays. Based on Lyapunov functional method, we present new delay-dependent conditions that guarantee both the exponential stability and an upper bound for some performance index. The criteria are delay-dependent conditions and are given in terms of linear matrix inequalities. Numerical examples are provided to illustrate the effectiveness of the results.
Sample-Path Analysis of Single-Server Queue with Multiple Vacations
Authors: El-Taha Muhammad
Published: July 2011

We a give deterministic (sample path) proof of a result that
extends the Pollaczek-Khintchine formula for a multiple vacation single-server queueing
model. We also give a conservation law for the same system with multiple classes. Our
results are completely rigorous and hold under weaker assumptions than those given in
the literature. We do not make stochastic assumptions, so the results hold almost surely
on every sample path of the stochastic process that describes the system evolution. The
article is self contained in that it gives a brief review of necessary background material.
Force Relaxation Characteristics of Medium Force Orthodontic Latex Elastics: A Pilot Study
Authors: Fernandes Daniel J. , Abrahão Gisele M. , Elias Carlos N. , Mendes Alvaro M.
Published: July 2011

To evaluate force extension relaxation of different brands and diameters of latex
elastics subjected to static tensile testing under an apparatus designed to simulate
oral environments, sample sizes of 5 elastics from American Orthodontics (AO), Tp, and Morelli Orthodontics (Mo) of equivalent medium force, (3/16, 1/4, and 5/16 inch size) were tested. The forces were read after 1-, 3-, 6-, 12- and 24-hour periods in
Emic testing machine with 30 mm/min cross-head speed and load cell of 20 N.
Two-way ANOVA and Bonferroni tests were used to identify statistical significance.
There were statistically differences among different manufacturers at all
observation intervals (P<0.0001). The relationships among loads at 24-hour time
period were as follows: Morelli>AO>Tp for 3/16, 1/4, and 5/16 elastics. The force
decay pattern showed a notable drop-off of forces until 3 hours, a slight increase in
some groups from 3–6 hours and a more homogeneous force pattern over 6–24
hours.
Human Tissue in the Evaluation of Safety and Efficacy of New Medicines: A Viable Alternative to Animal Models?
Authors: Coleman Robert A.
Published: July 2011

The pharma Industry's ability to develop safe and effective new drugs to market is in serious decline.
Arguably, a major contributor to this is the Industry's extensive reliance on nonhuman biology-based test methods to determine potential
safety and efficacy, objective analysis of which reveals poor predictive value. An obvious alternative approach is to use human-based tests,
but only if they are available, practical, and effective. While in vivo (phase 0 microdosing with high sensitivity mass spectroscopy)
and in silico (using established human biological data), technologies are increasingly being used, in vitro human approaches
are more rarely employed. However, not only are increasingly sophisticated in vitro test methods now available or under development,
but the basic ethically approved infrastructure through which human cells and tissues may be acquired is established. Along with clinical microdosing
and in silico approaches, more effective access to and use of human cells and tissues in vitro provide exciting and potentially
more effective opportunities for the assessment of safety and efficacy of new medicines.
Modification of a Volume-Overload Heart Failure Model to Track Myocardial Remodeling and Device-Related Reverse Remodeling
Authors: Tuzun Egemen , Bick Roger , Kadipasaoglu Cihan , Conger Jeffrey L. , Poindexter Brian J. , Gregoric Igor D. , Frazier O. H. , Towbin Jeffrey A. , Radovancevic Branislav
Published: July 2011

Purpose. To provide an ovine model of ventricular remodeling and reverse remodeling by creating congestive heart failure (CHF) and then treating it by implanting a left ventricular assist device (LVAD).
Methods. We induced volume-overload heart failure in 2 sheep; 20 weeks later, we implanted an LVAD and assessed recovery 11 weeks thereafter. We examined changes in histologic and hemodynamic data and levels of cellular markers of CHF.
Results. After CHF induction, we found increases in LV end-diastolic pressure, LV systolic and diastolic dimensions, wall thickness, left atrial diameter, and atrial natriuretic protein (ANP) and endothelin-1 (ET-1) levels; β-adrenergic receptor (BAR) and dystrophin expression decreased markedly. Biopsies confirmed LV remodeling. After LVAD support, LV systolic and diastolic dimensions, wall thickness, and mass, and ANP and ET-1 levels decreased. Histopathologic and hemodynamic markers improved, and BAR and dystrophin expression normalized.
Conclusions. We describe a successful sheep model for ventricular and reverse remodeling.
Comparison of Nitinol Stapes Pistons with Conventional Stapes Pistons: A Cadaver Study
Authors: Spear Samuel A. , Crawford James V.
Published: July 2011

Objective. To visually compare the Nitinol “smart” stapes prosthesis to conventional manual crimping stapes pistons in temporal bone cadaver specimens. Main Outcome Measures. 10 otolaryngologists were given a photograph of the randomly ordered stapes pistons and asked to use the pictures to answer questions about each stapes piston. The answers to the survey were then recorded for analysis. Results. 8 of 9 Nitinol pistons were described as circular, and 3 of 9 manual crimped pistons were described as circular (P< .05). 6 of 9 Nitinol pistons were considered to be in contact with >66% of the incus and 3 of 9 to be in contact with 34–66% of the incus. 3 of 9 manually crimped pistons were considered to be in contact with >66% of the incus, 3 with 34–66% contact and 3 with less than 34% contact. Conclusions. The Nitinol “smart” stapes pistons were considered to provide a more circular and circumferential crimping and to have greater contact with the long process of the incus than conventional stapes pistons.
Alzheimer’s Patients’ Spouses Critiques of the Support Services
Authors: Raivio Minna M. , Laakkonen Marja-Liisa , Pitkälä Kaisu H.
Published: July 2011

Introduction. Caregiving families of patients with dementia are often reluctant to use support services. The aim of this study was to describe their subjective critiques of these services.
Material and Methods. A cross-sectional questionnaire was sent to a random sample (N=1943) of Alzheimer’s patients’ spouses in Finland with an open-ended question: “What kind of problems have you faced with the services?” Their responses were analyzed with thematic content analysis.
Results. Of the responders identifying themselves as caregivers (N=1386), 728 (mean age 77.8, 65.1% females) responded. Opinions could be divided into two categories: (1) problems with the service application process (N=296); (2) critiques of the services offered (N=270) including either problems with community care support services or institutional care. 74 indicated that they had no need for services, and 15 praised the services they had received.
Conclusions. From the caregiver’s perspective, the service system is complicated, bureaucratic and works organization centredly.
Automated Three‐Chambered Social Approach Task for Mice
Authors: Yang Mu , Silverman Jill L. , Crawley Jacqueline N.
Published: July 2011

Autism is diagnosed by three major symptom categories: unusual reciprocal social interactions, impaired communication, and repetitive behaviors with restricted interests. Direct social approach in mice has strong face validity to simple social approach behaviors in humans, which are frequently impaired in autism. This unit presents a basic protocol for a standardized, high‐throughput social approach test for assaying mouse sociability. Our automated three‐chambered social approach task quantifies direct social approach behaviors when a subject mouse is presented with the choice of spending time with either a novel mouse or a novel object. Sociability is defined as the subject mouse spending more time in the chamber containing the novel target mouse than in the chamber containing the inanimate novel object. The Basic Protocol describes procedures for testing one subject at a time in a single apparatus. A Support Protocol addresses data collection. Curr. Protoc. Neurosci. 56:8.26.1‐8.26.16. © 2011 by John Wiley & Sons, Inc.
Stem‐Loop RT‐qPCR for miRNAs
Authors: Kramer Martha F.
Published: July 2011

This unit presents a specific and sensitive quantitative reverse‐transcription PCR (RT‐qPCR) method for measuring individual microRNAs (miRNAs) in tissue or cultured cells. miRNAs are 17 to 24 nucleotides (nt) in length. Standard and quantitative PCR methods require a template that is at least two times the length of either of the specific forward or reverse primers, each typically ∼20 nt in length. Thus, the target minimum length is ≥40 nt, making miRNAs too short for standard RT‐qPCR methods. In this assay, each of the RT‐qPCR nucleic acid reagents, including the RT‐primer, the forward and reverse PCR primers, and the hydrolysis probe, contain design features that, together, optimize miRNA specificity and assay sensitivity. The RT‐primer contains a highly stable stem‐loop structure that lengthens the target cDNA. The forward PCR primer adds additional length with nucleotides that optimize its melting temperature (Tm) and enhance assay specificity. The reverse primer disrupts the stem loop. Assay specificity is further optimized by placement of the probe over much of the original miRNA sequence, and the probe Tm is optimized by addition of a minor groove binding (MGB) moiety. Curr. Protoc. Mol. Biol. 95:15.10.1‐15.10.15. © 2011 by John Wiley & Sons, Inc.
Detection and Analysis of Proteins Modified by O‐Linked N‐Acetylglucosamine
Authors: Zachara Natasha E. , Vosseller Keith , Hart Gerald W.
Published: July 2011

O‐GlcNAc is a common post‐translational modification of nuclear, mitochondrial, and cytoplasmic proteins that is implicated in the etiology of type II diabetes and Alzheimer's disease, as well as cardioprotection. This unit covers simple and comprehensive techniques for identifying proteins modified by O‐GlcNAc, studying the enzymes that add and remove O‐GlcNAc, and mapping O‐GlcNAc modification sites. Curr. Protoc. Mol. Biol. 95:17.6.1‐17.6.33. © 2011 by John Wiley & Sons, Inc.
Simultaneous Single‐Molecule Mapping of Protein‐DNA Interactions and DNA Methylation by MAPit
Authors: Pardo Carolina E. , Darst Russell P. , Nabilsi Nancy H. , Delmas Amber L. , Kladde Michael P.
Published: July 2011

Sites of protein binding to DNA are inferred from footprints or spans of protection against a probing reagent. In most protocols, sites of accessibility to a probe are detected by mapping breaks in DNA strands. As discussed in this unit, such methods obscure molecular heterogeneity by averaging cuts at a given site over all DNA strands in a sample population. The DNA methyltransferase accessibility protocol for individual templates (MAPit), an alternative method described in this unit, localizes protein‐DNA interactions by probing with cytosine‐modifying DNA methyltransferases followed by bisulfite sequencing. Sequencing individual DNA products after amplification of bisulfite‐converted sequences permits assignment of the methylation status of every enzyme target site along a single DNA strand. Use of the GC‐methylating enzyme M.CviPI allows simultaneous mapping of chromatin accessibility and endogenous CpG methylation. MAPit is therefore the only footprinting method that can detect subpopulations of molecules with distinct patterns of protein binding or chromatin architecture and correlate them directly with the occurrence of endogenous methylation. Additional advantages of MAPit methylation footprinting as well as considerations for experimental design and potential sources of error are discussed. Curr. Protoc. Mol. Biol. 95:21.22.1‐21.22.18. © 2011 by John Wiley & Sons, Inc.
An Overview of Biochemical Genetics
Authors: Sharer J. Daniel
Published: July 2011

Biochemical genetics focuses on the pathophysiology, diagnosis, and treatment of inherited metabolic disorders. While individually rare, the combined incidence of these diseases is likely greater than 1:3000 live births. These conditions may present in the neonatal period as an acute, life‐threatening illness, or may manifest later in childhood with symptoms of progressive neurodegeneration, skeletal abnormalities, and/or dysmorphia. The purpose of this introductory unit is to provide an overview of the different clinical categories of metabolic disorders, modern diagnostic methods, and treatment options. Curr. Protoc. Hum. Genet. 70:17.1.1‐17.1.14 © 2011 by John Wiley & Sons, Inc.
Robust fault detection based on adaptive threshold generation using interval LPV observers
Authors: Montes de Oca Saúl , Puig Vicenç , Blesa Joaquim
Published: July 2011

In this paper, robust fault detection based on adaptive threshold generation of a non‐linear system described by means of a linear parameter‐varying (LPV) model is addressed. Adaptive threshold is generated using an interval LPV observer that generates a band of predicted outputs taking into account the parameter uncertainties bounded using intervals. An algorithm that propagates the uncertainty based on zonotopes is proposed. The design procedure of this interval LPV observer is implemented via pole placement using linear matrix inequalities. Finally, the minimum detectable fault is characterized using fault sensitivity analysis and residual uncertainty bounds. Two examples, one based on a quadruple‐tank system and another based on a two‐degree of freedom helicopter, are used to assess the validity of the proposed fault detection approach. Copyright © 2011 John Wiley & Sons, Ltd.
Isolation by distance between spouses and its effect on children's growth in height
Authors: Kozieł Sławomir , Danel Dariusz P. , Zaręba Monika
Published: July 2011

Heterosis is thought to be an important contributor to human growth and development. Marital distance (distance between parental birthplaces) is commonly considered as a factor favoring the occurrence of heterosis and can be used as a proximate measure of its level. The aim of this study is to assess the net effect of expected heterosis resulting from marital migration on the height of offspring, controlling for midparental height and socioeconomic status (SES). Height measurements on 2,675 boys and 2,603 girls ages 6 to 18 years from Ostrowiec Świętokrzyski, Poland were analyzed along with sociodemographic data from their parents. Midparental height was calculated as the average of the reported heights of the parents. Analyses revealed that marital distance, midparental height, and SES had a significant effect on height in boys and girls. The net effect of marital distance was much more marked in boys than girls, whereas other factors showed comparable effects. Marital distance appears to be an independent and important factor influencing the height of offspring. According to the “isolation by distance” hypothesis, greater distance between parental birthplaces may increase heterozygosity, potentially promoting heterosis. We propose that these conditions may result in reduced metabolic costs of growth among the heterozygous individuals. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Understanding adsorbate‐induced surface segregation in PtCo/C electrocatalyst
Authors: Budiman Abdul Hamid , Purwanto Widodo Wahyu , Dewi Eniya Listiani , Dalimi Rinaldy , Hwang Bing Joe
Published: July 2011

The X‐ray diffraction (XRD) was used to study the effect of treatment on particle size and catalyst structure of PtCo/C electrocatalysts. The XRD showed the grain sizes of N2‐treated electrocatalysts increase with temperature treatment, while those treated with CO remain the same. The X‐ray absorption spectroscopy (XAS) was used to study the changes in atomic distribution, extent of alloying as well as the surface population of PtCo/C nanoparticles. The XAS revealed that the time of CO treatments influence the surface population due to phase segregation. Catalysts treatment for 1, 3 and 5 h lead to higher population of Pt on the core and Co on the surface resulting in Pt rich in core—Co rich in shell. In contrast, CO treatments for 7, 10 and 15 h lead to higher population of Pt on the shell and Co on the core resulting in Pt rich in shell—Co rich in core. The electrochemical results showed that PtCo/C CO‐treatment is more active than commercial PtCo/C for the oxygen reduction reaction and it is found that PtCo/C CO‐treatment 3 h has the highest catalytic activity; because it has higher JPt and JCo values, indicating a higher extent of Pt and Co alloying. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
A Sufficient Condition for Checking the Attractiveness of a Sliding Manifold in Fractional Order Sliding Mode Control
Authors: Efe Mehmet Önder
Published: July 2011

Stability issues of fractional order sliding mode control laws are analyzed in this paper. For differentiation orders less than unity, it is shown that a stable reaching law in the fractional order case corresponds to a stable reaching law in the integer order case. The contribution of the current study is to explain the stability of the closed loop by the use of the Caputo and Riemann‐Liouville definitions of fractional order differentiation.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Anti‐Graffiti‐Systeme auf Mauerwerk im Bereich der Bundesfernstraßen
Authors: Müller Urs , von Weschpfennig Dieter , Malaga Katarina
Published: July 2011

Ingenieurbauten des Bundesfernstraßenbereichs sind aufgrund ihrer Exposition an vielen Stellen besonders betroffen von Graffiti. Graffitischmierer nehmen hierbei keine Rücksicht auf die Art der Substratmaterialien, und besonders poröse Untergründe bereiten Schwierigkeiten bei der Reinigung. Um Baustoffoberflächen besser zu schützen und von Graffiti leichter reinigen zu können, wurden in den vergangen Jahren spezielle Prophylaxesysteme (Anti‐Graffiti‐Systeme, AGS) entwickelten. Für die Beurteilung der Funktionalität und Verwendbarkeit dieser Anti‐Graffiti‐Systeme wurden von der Bundesanstalt für Straßenwesen (BASt) eine neue Technische Prüfvorschrift und Technische Lieferbedingungen (TP/TL AGS‐Beton) erarbeitet. Die TP/TL AGS‐Beton gilt hierbei nur für die Beurteilung von AGS auf Betonuntergründen. In einer Forschungsstudie wurde untersucht, inwieweit die vorhandene Prüfvorschrift für Betonsubstrate auch auf andere Untergründe, z. B. Naturstein oder Klinker, angewendet werden kann. Weiterhin wurde untersucht, welche Faktoren eine Rolle bei der Reinigung von mit AGS behandelten verschiedenen Substraten spielen.

Anti‐graffiti systems on masonry in the scope of the Federal Motorway System. Engineering structures of the Federal Motorway System are in particular vulnerable for graffiti smearing due to their location and exposition. Graffitists do not care about the type of substrate material. In particular porous materials cause great difficulties in the removal of graffiti. In order to protect construction material surfaces and to aid the cleaning from graffiti, anti‐graffiti systems (AGS) were developed in recent years. A new method for testing the cleaning efficacy and the durability of AGS was initiated by BASt together with technical delivery guidelines. However, the testing method and the delivery guidelines are designed for concrete surfaces. A scientific study investigated if the new testing method can be applied to other substrates as well, in particular to masonry or cladding of stone or brick. Additional factors influencing the cleaning efficacy of different substrates were analyzed.
Spielfreie und nachstellbare Führungs‐ und Festhaltekonstruktion für Brückenlager in Eisenbahnbrücken
Authors: Braun Joachim , Schulze Tobias , Schmidberger Michael , Tusche Jens
Published: July 2011

Die Gleis‐Brücken‐Interaktion beeinflusst in einem großen Ausmaß die Auswahl des Brückensystems, die Berechnung und die Konstruktion der Brücke wegen der Belastungen aus Schienenverkehr (Bremsen und Anfahren, etc.) und der Belastungen aus den Temperaturunterschieden. Die Hauptparameter unter Berücksichtigung der Konstruktion sind der Oberbau, die Ausdehnung des Überbaus, die Steifigkeiten des Unterbaus, Fugenkonstruktionen, Brückenlager und die Brückenplanung.

In diesem Beitrag wird auf Basis der aktuellen Vorschriftenlage die Problematik des Querversatzes an den beiden Überbauenden — auch “lateraler Versatz” genannt — aufgegriffen und für den Bereich der Brückenlager ein konstruktiver Lösungsansatz aufgezeigt.
Bau einer Schrägseilbrücke über die Save in Belgrad
Authors: Steinkühler Martin , Minas Frank
Published: July 2011

In sehr kurzer Bauzeit entsteht das neue Wahrzeichen der Hauptstadt der Republik Serbien. Die weltweit flächenmäßig größte einpylonige Schrägseilbrücke mit einem 45 m breiten Überbau überquert den Fluss Save 3 km vor der Mündung in die Donau. Ein 200 m hoher Pylon teilt die Brücke in einen 376 m langen Ganzstahlüberbau über die Save (Main Span) und einen 200 m langen Spannbetonquerschnitt über einen stillgelegten Seitenarm des Flusses (Back Span). Die weitere Anbindung erfolgt über einen 338 m langen einzelligen Spannbetonhohlkasten (Side Span) sowie Rampenbauwerke.

Ein internationales Konsortium wurde 2008 mit Planung und Bau gemäß FIDIC beauftragt. Der Bau einer Brücke mit solchen außergewöhnlichen Abmessungen in Kombination mit unterschiedlichen Baustoffen in einem im Umbruch befindlichen und von 15 Jahren Embargo geprägten Land führte gar zu einer Beachtung durch den Discovery Channel für die Sendung “Extreme Engineering”.

Construction of a Stay Cable Bridge crossing River Sava in Belgrade. A new landmark for the capital of Republic Serbia is constructed in a very short time. The largest one pyloned stayed cable bridge of the world with a deck width of 45 m crosses river Sava 3 km before it leads into the Danube. The 200 m high pylon divides the bridge deck into a 376 m long Main Span crossing the river and a 200 m wide Back Span crossing a bay. The bridge consists Bild 1. Satellitenaufnahme von Belgrad mit Lage der Save Brücke Fig. 1. Location of Sava Bridge further within the 338 m long Side Span on a post‐tensioned hollow box girder. An international joint venture won in 2008 the FIDIC Contract to design and build the bridge. A bridge with such extreme dimensions combined with different construction materials and different construction methods in an environment with war and embargo history even led to consideration of Discovery Channel for its series ”Extreme Engineering”.
Large‐scale, high‐solids enzymatic hydrolysis of steam‐exploded poplar
Authors: Di Risio S. , Hu C. S. , Saville B. A. , Liao D. , Lortie J.
Published: July 2011

Enzymatic hydrolysis at high solids loadings is key to scale‐up of lignocellulosic biochemical conversion processes, because of potentially higher sugar and ethanol titers and lower hydraulic loads. However, high solids loadings can pose rheological challenges, reduce mass and heat transfer efficiency, and increase the concentration of enzyme inhibitors in the system, resulting in low conversion of glucan and xylan into fermentable sugars. In this study, ten batch enzymatic hydrolyses were conducted in a 200‐liter reactor, while monitoring sugar and inhibitor profiles. The effects of enzyme cocktail, biomass loading, pre‐treatment severity, and hydrolysis temperature were assessed using techno‐economic indicators to evaluate the efficacy of the enzymatic hydrolysis. For similar experimental conditions, different enzyme cocktails produced distinct hydrolysis outcomes allowing cocktail optimization. In spite of a rapid initial reaction rate, fermentable sugars concentrations reached a plateau after about 48 h, indicating severe inhibition. Increased biomass loadings did not proportionally increase sugar production. Both observations indicated the presence of severe inhibition, likely endogenous. Pre‐treatment at a lower severity (200°C for 8 min) led to the most efficient hydrolysis, while higher severities destroyed hemicellulose and led to lower overall sugar production. Lower saccharification temperatures (30–32°C) caused a 20% decrease in sugar conversion when compared to 50°C operation. Strategies to mitigate inhibition will be required if high‐solids enzyme hydrolysis is to be successfully scaled up to commercially relevant levels. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Development of hybrid baculovirus vectors for artificial MicroRNA delivery and prolonged gene suppression
Authors: Chen Chiu‐Ling , Luo Wen‐Yi , Lo Wen‐Hsin , Lin Kun‐Ju , Sung Li‐Yu , Shih Yung‐Shen , Chang Yu‐Han , Hu Yu‐Chen
Published: July 2011

MicroRNA (miRNA) plays essential roles in regulating gene expression, but miRNA delivery remains a hurdle, thus entailing a vector system for efficient transfer. Baculovirus emerges as a promising gene delivery vector but its inherent transient expression restricts its applications in some scenarios. Therefore, this study primarily aimed to develop baculovirus as a miRNA expression vector for prolonged gene suppression. We constructed recombinant baculoviruses carrying artificial egfp‐targeting miRNA sequences within the miR155 backbone, which after expression by the cytomegalovirus promoter could knockdown the enhanced green fluorescent protein (EGFP) expression in a sequence‐ and dose‐dependent manner. By swapping the mature miRNA sequences, the baculovirus miRNA shuttle effectively repressed the overexpression of endogenous TNF‐α in arthritic synoviocytes without inducing apoptosis. To prolong the baculovirus‐mediated expression, we further developed a hybrid baculovirus vector that exploited the Sleeping Beauty (SB) transposon for gene integration and sustained miRNA expression. The hybrid baculovirus vector that combined the miR155 scaffold and SB transposon effectively repressed the transgene expression for a prolonged period of time, hence diversifying the applications of baculovirus to indications necessitating prolonged gene regulation such as arthritis. Biotechnol. Bioeng. 2011;108: 2958–2967. © 2011 Wiley Periodicals, Inc.
Physical degradation of proteins in well‐defined fluid flows studied within a four‐roll apparatus
Authors: Simon S. , Krause H. J. , Weber C. , Peukert W.
Published: July 2011

In most applications of biotechnology and downstream processing proteins are exposed to fluid stresses in various flow configurations which often lead to the formation of unwanted protein aggregates. In this paper we present physical degradation experiments for proteins under well‐defined flow conditions in a four‐roll apparatus. The flow field was characterized numerically by computational fluid dynamics (CFD) and experimentally by particle image velocimetry (PIV). The local shear strain rate as well as the local shear and elongation rate was used to characterize the hydrodynamic stress environment acting on the proteins. Lysozyme was used as a model protein and subjected to well‐defined fluid stresses in high and low stress environment. By using in situ turbidity measurements during stressing the aggregate formation was monitored directly in the fluid flow. An increase in absorbance at 350 nm was attributed to a higher content of visible particles (>1 µm). In addition to lysozyme, the formation of aggregates was confirmed for two larger proteins (bovine serum albumin and alcohol dehydrogenase). Thus, the presented experimental setup is a helpful tool to monitor flow‐induced protein aggregation with high reproducibility. For instance, screening experiments for formulation development of biopharmaceuticals for fill and finish operations can be performed in the lab‐scale in a short time‐period if the stress distributions in the application are transferred and applied in the four‐roll mill. Biotechnol. Bioeng. 2011;108: 2914–2922. © 2011 Wiley Periodicals, Inc.
Tuning structural durability of yeast‐encapsulating alginate gel beads with interpenetrating networks for sustained bioethanol production
Authors: Cha Chaenyung , Kim Soo Rin , Jin Yong‐Su , Kong Hyunjoon
Published: July 2011

Microorganisms have become key components in many biotechnological processes to produce various chemicals and biofuels. The encapsulation of microbial cells in calcium cross‐linked alginate gel beads has been extensively studied due to several advantages over using free cells. However, industrial use of alginate gel beads has been hampered by the low structural stability of the beads. In this study, we demonstrate that the incorporation of interpenetrating covalent cross‐links in an ionically cross‐linked alginate gel bead significantly enhances the bead's structural durability. The interpenetrating network (IPN) was prepared by first cross‐linking alginate chemically modified with methacrylic groups, termed methacrylic alginate (MA), with calcium ions and subsequently conducting a photo cross‐linking reaction. The resulting methacrylic alginate gel beads (IPN‐MA) exhibited higher stiffness, ultimate strength and ultimate strain and also remained more stable in media either subjected to high shear or supplemented with chelating agents than calcium cross‐linked alginate gel beads. Furthermore, yeast cells encapsulated in IPN‐MA gel beads remained more metabolically active in ethanol production than those in calcium cross‐linked alginate gel beads. Overall, the results of this study will be highly useful in designing encapsulation devices with improved structural durability for a broad array of prokaryotic and eukaryotic cells used in biochemical and industrial processes. Biotechnol. Bioeng. 2012;109: 63–73. © 2011 Wiley Periodicals, Inc.
Engineering the pentose phosphate pathway to improve hydrogen yield in recombinant Escherichia coli
Authors: Kim Young Mi , Cho Han‐Saem , Jung Gyoo Yeol , Park Jong Moon
Published: July 2011

Among various routes for the biological hydrogen production, the NAD(P)H‐dependent pentose phosphate (PP) pathway is the most efficient for the dark fermentation. Few studies, however, have focused on the glucose‐6‐phosphate 1‐dehydrogenase, encoded by zwf, as a key enzyme activating the PP pathway. Although the gluconeogenic activity is essential for activating the PP pathway, it is difficult to enhance the NADPH production by regulating only this activity because the gluconeogenesis is robust and highly sensitive to concentrations of glucose and AMP inside the cell. In this study, the FBPase II (encoded by glpX), a regulation‐insensitive enzyme in the gluconeogenic pathway, was activated. Physiological studies of several recombinant, ferredoxin‐dependent hydrogenase system‐containing Escherichia coli BL21(DE3) strains showed that overexpression of glpX alone could increase the hydrogen yield by 1.48‐fold compared to a strain with the ferredoxin‐dependent hydrogenase system only; the co‐overexpression of glpX with zwf increased the hydrogen yield further to 2.32‐fold. These results indicate that activation of the PP pathway by glpX overexpression‐enhanced gluconeogenic flux is crucial for the increase of NAD(P)H‐dependent hydrogen production in E. coli BL21(DE3). Biotechnol. Bioeng. 2011;108: 2941–2946. © 2011 Wiley Periodicals, Inc.
Ultra high‐performance liquid chromatography of porphyrins
Authors: Benton Christopher M. , Lim Chang Kee , Ritchie Harald J. , Moniz Caje , Jones Donald J.L.
Published: July 2011

An ultra high‐performance liquid chromatographic (UHPLC) system was developed and optimized for the separation of porphyrins of clinical interest. Optimum conditions for the simultaneous separation of uroporphyrin, hepta‐, hexa‐, penta‐carboxylic acid porphyrins and coproporphyrin and their type I and III isomers on a Thermo Hypersil BDS C18 column (2.4 µm particle size, 100 × 2.1 mm i.d.) using a gradient elution with 10% (v/v) acetonitrile in 1.0 m ammonium acetate buffer (pH 5.16) and 10% (v/v) acetonitrile in methanol at a flow‐rate of 0.4 mL/min. The effect of mobile phase buffer molarity on the sensitivity of fluorescence detection and resolution of porphyrin isomers was investigated. The method was successfully applied to the analysis of porphyrins extracted from the urine and faeces of patients with various human porphyrias. Copyright © 2011 John Wiley & Sons, Ltd.
Lagrange, Hamilton, Schrödinger, and computers
Authors: Fazarinc Zvonko
Published: July 2011

The subtitle of this article could be “Modern engineer meets the masters of mathematical physics.” While there is no way to know how the masters would use our modern technology, we can educate ourselves in their way of thinking and adapt their mathematical methods to our computational capabilities. This article attempts to do just that and illustrates the findings with examples from dynamics, electro‐magnetics, and quantum mechanics. It does this from the engineer's viewpoint and in keeping with the mission of the Computer Applications in Engineering Education publication. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:238–251, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.20550
Impact of renal insufficiency on safety and efficacy of drug‐eluting stents compared to bare‐metal stents at 6 years
Authors: Simsek Cihan , Magro Michael , Boersma Eric , Onuma Yoshinobu , Nauta Sjoerd , Valstar Gideon , van Geuns Robert‐Jan , van der Giessen Willem , van Domburg Ron , Serruys Patrick ,   Interventional Cardiologists of the Thoraxcenter
Published: July 2011

Background: There is few information on the long‐term efficacy and safety of sirolimus‐eluting stents (SES) and paclitaxel‐eluting stents (PES) compared to bare metal stents (BMS) in all‐comer percutaneous coronary intervention (PCI)—patients complicated by renal insufficiency (RI). Objective: Our aim was to assess the 6‐year clinical outcome of PCI‐patients with RI treated exclusively with BMS, SES, or PES in our academic hospital. Methods: A total of 1382 patients, included in three cohorts of consecutive PCI‐patients (BMS = 392; SES = 498; PES = 492), were categorized by creatinine clearance calculated by the Cockroft–Gault formula (normal kidney function ≥ 90; mild RI = 60–89; moderate RI < 60) and systematically followed for the occurrence of major adverse cardiac events (MACE). Results: Mortality rates were significantly higher for patients with moderate RI compared to mild RI and normal kidney function at 6 years (Kaplan–Meier estimate: moderate RI (34%) vs. mild RI (12%), P < 0.001; moderate RI (34%) vs. normal kidney function (8%), P < 0.001). After multivariate Cox‐regression analysis, SES and PES decreased the occurrence of target‐vessel revascularization (TVR) and MACE at 6 years in patients with a normal creatinine clearance compared to BMS [adjusted hazard ratio (aHR) = 0.48, 95% CI: 0.28–0.84; aHR = 0.75, 95% CI: 0.57–0.97, respectively] with no significant effect on mortality. Safety‐ and efficacy end points were comparable for the three stent types in patients with mild‐ and moderate renal function. Conclusion: Patients with a normal creatinine clearance had significant improvement in TVR and MACE rates after SES‐ or PES implantation compared to BMS at 6 years. However, there was no superiority of both drug‐eluting stents over BMS in safety and efficacy end points for patients with impaired renal function. © 2012 Wiley Periodicals, Inc.
SBA‐15‐Type Organosilica with 4‐Mercapto‐N,N‐bis‐(3‐Si‐propyl)butanamide for Palladium Scavenging and Cross‐Coupling Catalysis
Authors: El Hankari Samir , El Kadib Abdelkrim , Finiels Annie , Bouhaouss Ahmed , Moreau Joël J. E. , Crudden Cathleen M. , Brunel Daniel , Hesemann Peter
Published: July 2011

This work describes the synthesis of novel functional silica materials with difunctional thiol–amide substructures and featuring regular architectures on a mesoscopic level. The functional materials were synthesised by both one‐pot co‐condensation and post‐grafting approaches. The thiol groups confined in the matrix were found to be efficient for palladium entrapment, leading to highly active and reusable heterogeneous catalysts for Sonogashira and Suzuki–Miyaura cross‐coupling reactions. This work evidences the crucial role of both the thiol precursor and the condensation degree of the silica scaffold in view of the design of stable and reusable tailor‐made mesoporous catalytic silica materials.
Crystal Growth of Clathrate Hydrate in Gas/Liquid/Liquid System: Variations in Crystal‐Growth Behavior
Authors: Ishida Yosuke , Sakemoto Riki , Ohmura Ryo
Published: July 2011

This paper reports the visual observations of the formation and growth of structure‐II hydrate crystals on a water droplet partially immersed in liquid cyclopentane and exposed to difluoromethane gas. Each of the experiments was performed under prescribed temperature and pressure conditions in the range from 281.7 to 297.0 K and from 0.12 to 1.10 MPa in order to investigate the effect of the driving force for the hydrate crystal growth. The experiments were conducted at 25 different temperature–pressure conditions. It was found that the behavior of the hydrate crystal growth in this three‐component system can be classified into three modes, which we called “cover”, “expansion” and “line”, depending on the temperature and pressure. The descriptions of the three types are summarized as follows. “Cover”: Hydrate crystals first formed on the water‐droplet surface and then grew to form a polycrystalline layer covering the surface. After complete surface coverage, no more hydrate growth and little change in the shape of the hydrate‐covered water droplet were observed. “Expansion”: Like “cover”, the first crystals were observed on the water‐droplet surface. They grew not only along the surface, but also toward the gas phase, and then continued to grow for more than several tens of minutes after complete coverage. “Line”: Unlike the other two modes, hydrate crystals first formed at the three‐phase interfacial line and grew along this line. The shape of the hydrate crystals eventually became like a doughnut, since the center of the water droplet collapsed when they grew.
Two‐Step Electrochemically Directed Synthesis of Pr4N(TCNQ)n(n=1, 2): Preparation, Structure, and Properties of a Magnetically Isolated Dimer and a Quasi‐One‐Dimensional Chain
Authors: Qu Xiaohu , Lu Jinzhen , Boas John F. , Bond Alan M. , Martin Lisandra L.
Published: July 2011

Solid‐state electrochemistry of a tetracyanoquinodimethane (TCNQ)‐modified electrode in contact with a tetrapropylammonium cation (Pr4N+) electrolyte showed two electron‐transfer steps to give Pr4N(TCNQ)2(1) and Pr4N(TCNQ) (2) rather than the traditional one‐electron step to directly give Pr4N(TCNQ). Two thermodynamically stable Pr4N+TCNQ stoichiometries,1and2, were synthesized and characterized. The degree of charge transfer (ρ) calculated from the crystal structure is −0.5 for the TCNQ moieties in1and −1.0 for those in2. Raman spectra for Pr4N(TCNQ)2show only one resonance for the extracyclic CC stretching at 1423 cm−1, which lies approximately midway between that of TCNQ at 1454 cm−1and TCNQ−at 1380 cm−1. Both the magnetic susceptibility and EPR spectra are temperature‐dependent, with a magnetic moment close to that for one unpaired electron per (TCNQ)2unit in1, whereas2is almost diamagnetic. Pressed discs of both complexes show conductivity (1–2×10−5 S cm−1) in the semiconductor range. For1, the position of zero current for the steady‐state voltammograms implies 50 % of TCNQ−and 50 % TCNQ0is present in solution, thereby supporting a dissociation of (TCNQ)2−in solution, but is indicative of only TCNQ−being present for2.
Structure, Magnetism and Theory of a Family of Nonanuclear CuII5LnIII4–Triethanolamine Clusters Displaying Single‐Molecule Magnet Behaviour
Authors: Langley Stuart K. , Ungur Liviu , Chilton Nicholas F. , Moubaraki Boujemaa , Chibotaru Liviu F. , Murray Keith S.
Published: July 2011

Synthesis, crystal structures and magnetic studies are reported for four new heterometallic CuII–LnIII clusters. The reaction of Cu(NO3)2⋅3H2O with triethanolamine (teaH3), pivalic acid, triethylamine and Ln(NO3)3⋅6H2O (Ln=Gd, Tb, Dy and Ho) results in the formation of four isostructural nonanuclear complexes of general formula [CuII5LnIII4O2(teaH)4{O2CC(CH3)3}2(NO3)4(OMe)4]⋅2MeOH⋅2Et2O [Ln=Gd (1), Tb (2), Dy (3) and Ho (4)]. The metal core of each cluster is made up of four face‐ and vertex‐sharing tetrahedral units. Solid‐state DC magnetic susceptibility studies reveal competing anti‐ and ferromagnetic interactions within each cluster leading to large‐spin ground states for 1–4. Solid‐state AC magnetic susceptibility studies show frequency‐dependent out‐of‐phase (${\chi {^\prime}{^\prime}_{\rm{M}} }$) signals for 2–4 below 4 K, suggestive of single‐molecule magnet behaviour. Ab initio calculations on one of the anisotropic examples (3) provided a rare set of J values for Dy–Cu and Cu–Cu exchange interactions (Dy–Dy zero), some ferro‐ and some antiferromagnetic in character, that explain its magnetic behaviour.
Moderate and Advanced Intramolecular Proton Transfer in Urea–Anion Hydrogen‐Bonded Complexes
Authors: Baggi Giorgio , Boiocchi Massimo , Fabbrizzi Luigi , Mosca Lorenzo
Published: July 2011

The study of the interactions of the three urea‐based receptors AH, BH+ and CH2+ with a variety of anions, in MeCN, has made it possible to verify the current view that hydrogen bonding is frozen proton transfer from the donor (the urea NH fragment in this case) to the acceptor (the anion X−). The poorly acidic, neutral receptor AH establishes two equivalent hydrogen bonds NH⋅⋅⋅X−, with all anions, including CH3COO− and F−, in which moderate proton transfer from NH to the anion takes place. The strongly acidic, dicationic receptor CH2+ forms, with most anions, complexes in which two inequivalent hydrogen bonds are present: one involving moderate proton transfer (NH⋅⋅⋅X−) and one in which advanced proton transfer has taken place, described as N−⋅⋅⋅HX. The degree of proton advancement is directly related to the basic tendencies of the anion. The cationic receptor BH+ of intermediate acidic properties only forms complexes with two inequivalent hydrogen bonds (moderate+advanced proton transfer) with CH3COO− and F−, and complexes with two equivalent hydrogen bonds (moderate proton transfer) with all the other anions. Moreover, [B⋅⋅⋅HF] and [C⋅⋅⋅HF]+, on addition of a second F− ion, lose the bound HF molecule to give HF2−. Release of CH3COOH, with the formation of [CH3COOH⋅⋅⋅CH3COO]−, also takes place with the [B⋅⋅⋅CH3COOH] complex in the presence of a large excess of anion.