bluuebunny/crossref_metadata_2025 huggingface dataset:
Program comprehension for domain-specific languages
Authors: Pereira Maria , Mernik Marjan , da Cruz , Henriques Pedro
Published: March 2009

In the past, we have been looking for program comprehension tools that are able to interconnect operational and behavioral views, aiming at aiding the software analyst to relate problem and program domains in order to reach a full understanding of software systems. In this paper we are concerned with Program Comprehension issues applied to Domain Specific Languages (DSLs). We are now willing to understand how techniques and tools for the comprehension of traditional programming languages fit in the understanding of DSLs. Being the language tailored for the description of problems in a specific domain, we believe that specific visualizations (at a higher abstraction level, closer to the problem level) could and should be defined to enhance the comprehension of the descriptions in that particular domain. .
Interaction of Novel Metal Complexes with DNA: Synthetic and Structural Aspects
Authors: Spingler Bernhard , Da Pieve Chiara , Medina-Molner Alfredo , Antoni Philipp M. , Santangelo Maria Grazia
Published: March 2009

Metal ions bind to nucleic acids at various positions. This binding can be modulated by using metal complexes with appropriate ligands. Novel mono- and especially dinuclear metal complexes could be a powerful tool to detect rare, but still physiologically relevant, forms of DNA, e.g.
the left-handed Z-DNA. In this review, our recent research activities in this area of bioinorganic chemistry are summarized. A special emphasis is laid on the synthetic challenges that arose upon the synthesis of the polyamine ligands. Further, some rather unusual approaches to elucidate the
solution structure of copper bound to guanosine monophosphate with the help of pulsed EPR techniques like ENDOR and HYSCORE are described.
Overview of Gene Silencing by RNA Interference
Authors: Kim Daniel H. , Rossi John J.
Published: March 2009

The potential of harnessing RNA interference (RNAi) for sequence‐specific gene silencing has generated much excitement and progress in the field. Recent advances in RNAi technology suggest that RNAi‐based approaches may soon become an effective therapeutic strategy against a myriad of diseases. This overview provides a brief description of important considerations when designing an RNAi‐based method for gene silencing and therapeutic development: (a) mechanistic aspects of RNAi‐mediated gene silencing in mammalian cells; (b) structural requirements for potent siRNA duplexes; (c) off‐target effects and interferon responses; and (d) effective delivery of RNAi‐inducing agents. Promising therapeutic applications of RNAi that are currently in the developmental pipeline are also described. Curr. Protoc. Nucleic Acid Chem. 36:16.1.1‐16.1.10. © 2009 by John Wiley & Sons, Inc.
Unusual Deactivation in the Asymmetric Hydrogenation of Itaconic Acid
Authors: Schmidt Thomas , Drexler Hans‐Joachim , Sun Jiangtao , Dai Zhenya , Baumann Wolfgang , Preetz Angelika , Heller Detlef
Published: March 2009

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During the asymmetric hydrogenation of itaconic acid with rhodium solvate complexes of the type [Rh(PP)(MeOH)2] BF4 (PP=DIPAMP, Me‐DuPHOS) a deactivation with increasing substrate concentration is observed. It is shown that this inhibition phenomenon is due to the in situ formation of an inactive rhodium(III)‐alkyl complex. Two crystal structures of single crystals of the responsible complexes (1) and (2) support the deactivation pathway.
A narrow and highly significant linkage signal for severe bipolar disorder in the chromosome 5q33 region in Latin American pedigrees
Authors: Jasinska A.J. , Service S. , Jawaheer D. , DeYoung J. , Levinson M. , Zhang Z. , Kremeyer B. , Muller H. , Aldana I. , Garcia J. , Restrepo G. , Lopez C. , Palacio C. , Duque C. , Parra M. , Vega J. , Ortiz D. , Bedoya G. , Mathews C. , Davanzo P. , Fournier E. , Bejarano J. , Ramirez M. , Araya Ortiz C. , Araya X. , Molina J. , Sabatti C. , Reus V. , Ospina J. , Macaya G. , Ruiz‐Linares A. , Freimer N.B.
Published: March 2009

We previously reported linkage of bipolar disorder to 5q33‐q34 in families from two closely related population isolates, the Central Valley of Costa Rica (CVCR) and Antioquia, Colombia (CO). Here we present follow up results from fine‐scale mapping in large CVCR and CO families segregating severe bipolar disorder, BP‐I, and in 343 population trios/duos from CVCR and CO. Employing densely spaced SNPs to fine map the prior linkage peak region increases linkage evidence and clarifies the position of the putative BP‐I locus. We performed two‐point linkage analysis with 1134 SNPs in an approximately 9 Mb region between markers D5S410 and D5S422. Combining pedigrees from CVCR and CO yields a LOD score of 4.9 at SNP rs10035961. Two other SNPs (rs7721142 and rs1422795) within the same 94 kb region also displayed LOD scores greater than 4. This linkage peak coincides with our prior microsatellite results and suggests a narrowed BP‐I susceptibility regions in these families. To investigate if the locus implicated in the familial form of BP‐I also contributes to disease risk in the population, we followed up the family results with association analysis in duo and trio samples, obtaining signals within 2 Mb of the peak linkage signal in the pedigrees; rs12523547 and rs267015 (P = 0.00004 and 0.00016, respectively) in the CO sample and rs244960 in the CVCR sample and the combined sample, with P = 0.00032 and 0.00016, respectively. It remains unclear whether these association results reflect the same locus contributing to BP susceptibility within the extended pedigrees. © 2009 Wiley‐Liss, Inc.
Die chemische Biologie von Aptameren
Authors: Mayer Günter
Published: March 2009

An einem Strang: Aptamere, kurze einzelsträngige Oligonucleotide mit klar definierter 3D‐Faltung, sind hoch affin und spezifisch für ihre Zielstrukturen und hemmen deren biologische Funktionen. Aptamere können chemisch und/oder enzymatisch hergestellt werden und lassen sich daher als chemische wie auch als biologische Substanzen einordnen. Der aktuelle Stand und neue Entwicklungen auf diesem Gebiet werden vorgestellt.

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Aptamere sind kurze einzelsträngige Nucleinsäuren mit einer klar definierten dreidimensionalen Faltung. Sie zeigen eine hohe Affinität und Spezifität für ihre Zielstrukturen und inhibieren deren biologische Funktionen. Aptamere gehören zur Stoffklasse der Nucleinsäuren und können entweder chemisch, enzymatisch oder durch Kombination beider Methoden hergestellt werden. Daher können Aptamere sowohl als chemische wie auch als biologische Substanzen eingeordnet werden. Etablierte Methoden ebenso wie neue Entwicklungen auf dem Gebiet der Aptamere sollen in diesem Aufsatz zusammengefasst werden. Die Verwendung von Aptameren in der chemischen Biologie wird diskutiert.
Cover Picture: Compartmentalization of Chemically Separated Components into Droplets (Angew. Chem. Int. Ed. 15/2009)
Authors: Edgar J. Scott , Milne Graham , Zhao Yiqiong , Pabbati Chaitanya P. , Lim David S. W. , Chiu Daniel T.
Published: March 2009

Electroosmotic‐flow‐driven droplet generation integrated with capillary electrophoresis (CE) allows the molecular components separated by CE to be compartmentalized into a stream of droplets, as reported by D. T. Chiu and co‐workers in their Communication on page 2719 ff. and illustrated on the cover picture. After separation and droplet compartmentalization, the droplet‐confined bands either can be docked and studied on‐chip or removed off‐chip for a second‐dimension separation and further analysis.

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Inside Cover: Artificial Ribozyme Switches Containing Natural Riboswitch Aptamer Domains (Angew. Chem. Int. Ed. 15/2009)
Authors: Wieland Markus , Benz Armin , Klauser Benedikt , Hartig Jörg S.
Published: March 2009

Fusions of a ribozyme and an aptamer of a natural riboswitch (thiamine pyrophosphate, TPP) are used to construct artificial thiamine‐dependent switches of gene expression. As J. S. Hartig et al. describe in their Communication on page 2715 ff., insertion of these RNA elements into bacterial mRNAs allows translation of the message to be switched on or off. TPP triggers changes to the ribozyme‐mediated mRNA cleavage, resulting in liberation of the message for translational initiation.

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Comparative study of the mechanical properties of fiber‐reinforced denture base resin
Authors: Köroğlu Ayşegül , Özdemir Tonguç , Usanmaz Ali
Published: March 2009

Poly(methyl methacrylate) (PMMA) is used for removable prostheses. However, PMMA denture base resin does not meet all the mechanical requirements of prostheses. The aim of this in vitro study was to compare the transverse strength, modulus of elasticity, and impact strength values of nonreinforced heat‐polymerized and microwave‐polymerized denture base resin with those of denture base resin reinforced with continuous unidirectional E‐glass, woven E‐glass, and ultrahigh‐molecular‐weight polyethylene fibers. The mechanical properties of polymer reinforced with polyethylene fibers showed no significant increase in flexural properties. However, reinforcement with Stick fiber improved the mechanical properties. The test specimens that expressed low fracture strength values showed void spaces inside the test specimens. © 2009 Wiley Periodicals, Inc. J Appl Polym, 2009
Bulk free‐radical polymerization of styrene on a spinning disc reactor
Authors: Moghbeli M. R. , Mohammadi S. , Alavi S. M.
Published: March 2009

The bulk free‐radical polymerization of styrene was carried out on a spinning disc reactor (SDR) with prepolymer feeds previously prepared in a stirred batch reactor at 70°C. The SDR significantly enhanced the reaction rate when the conversion of the prepolymer feed was about 50%. There was an optimal disc rotation speed, that is, 1500 rpm, at which the conversion enhancement was maximized. Increasing the disc rotation speed up to 1500 rpm increased the conversion, but a further increase beyond this speed caused the conversion enhancement to decrease. This behavior could be attributed to the dual effect of the disc speed (controlling both the residence time and the effective radial mixing of the reaction media) on the disc. On the other hand, the multipass disc feeding mode was used as an approach to increase the residence time and evolution of the conversion of the reacting mixture in the SDR. Surprisingly, a maximum conversion change of about 40% was achieved for a prepolymer feed of 50% after three passes across the rotating disc. Furthermore, the effect of multipass disc feeding on the molecular characteristics of the SDR products was investigated. In comparison with the results obtained at a feed conversion of 30%, the weight‐average molecular weight, the z‐average molecular weight, and the polydispersity index of the three‐pass SDR products prepared with a 50% feed conversion at a rotation speed of 1500 rpm were lower than those of the one‐pass products. This behavior could be attributed to probable chain scission of long polymer chains as a result of the high shear and elongation forces that arose on the disc surface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Quantifying allowable harm in species at risk: application to the Laurentian black redhorse (Moxostoma duquesnei)
Authors: Vélez‐Espino Luis A. , Koops Marten A.
Published: March 2009

When a species is identified for conservation, often the only way to effect recovery is to reduce the harm imposed by stressors threatening the survival of the species. Ideally all threats would be removed; however, this is often not feasible or practical. Within this context, a demographic approach is presented to assess how much human‐induced harm could be allowed without impairing the persistence of the species. Harm is defined as a negative perturbation that can target one or more vital rates and life stages simultaneously.

Allowable harm, defined as a level of harm that will not jeopardize survival or recovery, will be a function of the vital rates affected by human actions, the sensitivity of population growth to changes in these vital rates (their elasticities), the population growth rate prevailing before harm occurs, and the set of demographic parameters considered safe for long‐term persistence. This life‐history based approach requires minimal data, can link demography with habitat‐explicit information, is flexible enough to encompass complex life histories, and follows a precautionary approach.

Quantification of allowable harm could be applied to any species at risk. This approach is introduced by applying it to a Canadian population of a freshwater fish, the black redhorse (Moxostoma duquesnei), demonstrating that in the absence of habitat constraints population dynamics of this species are most sensitive to the survival of young adults, but population fitness is particularly sensitive to the loss of habitat used by young‐of‐the‐year fish under current levels of habitat supply.

Copyright © 2009 John Wiley & Sons, Ltd.
Detection of resistive features using towed slingram electromagnetic induction instruments
Authors: Thiesson Julien , Dabas Michel , Flageul Sébastien
Published: March 2009

Slingram frequency domain electromagnetic (FDEM) instruments allow simultaneous measurement of both magnetic susceptibility and electrical conductivity, which should justify their widespread use in archaeological surveying. However, this is not the case and their application remains quite limited due to: (i) a lack of knowledge about the role of coil orientation and spacing in terms of the detection abilities for archaeological features (especially for resistive bodies); and (ii) a lack of instrumentation specifically designed for shallow targets. We present here a test of a new version of the CS60 instrument (VCP coil configuration and 0.6 m intercoil spacing) for shallow depth resistive feature detection. This experiment was undertaken on the Roman site of Vieil‐Evreux where a complete series of control resistivity and radar data was obtained. Detection of buried Roman walls was successful, in accordance with what can be expected from three‐dimensional modelling. This confirms that the application of this type of instrument in archaeological surveys merits to be extended significantly. Copyright © 2009 John Wiley & Sons, Ltd.
A highly sensitive method for the determination of 7‐aminonitrazepam, a metabolite of nitrazepam, in human urine using high‐performance electrospray liquid chromatography tandem mass spectrometry
Authors: Kuang Hua , Li Qiusheng , Shen Chongyu , Xu Jinzhong , Yuan Yuan , Xu Chuanlai , Wang Wuyang
Published: March 2009

A highly sensitive method has been developed for the determination of urinary 7‐aminonitrazepam (7‐ANZP), the major metabolite of nitrazepam, using high‐performance electrospray liquid chromatography tandem mass spectrometry. The samples were prepared for analysis by adding 7‐aminoclonazepam (7‐ACZP, internal standard), hydrolysis with β‐glucuronidase and liquid–liquid extraction. Mass spectral acquisition was achieved by selectively monitoring the reaction between the two diagnostic transition reactions. Qualitative analysis was based on the retention time, and the quantitation was carried out by comparison with the internal standard. The recoveries of different concentrations of 7‐ANZP from spiked blank samples was 89.0–95.2%, and the relative standard deviation was below 6.4%. The limit of determination in urine was 0.07 ng/mL, and the limit of quantitation was 0.5 ng/mL in the linear range of 1–50 ng/mL. This method possesses the merits of convenient operation, high sensitivity and good repeatability, making it a practical method for analysis of 7‐ANZP in urine. Copyright © 2009 John Wiley & Sons, Ltd.
Simultaneous determination of six herbal components in intestinal perfusate by high‐performance liquid chromatography
Authors: Wang Zhanguo , Du Qingqing , Qiu Xuelan , Liu Fang , Tan Fei , Lan Ke , Jiang Xuehua , Jiang Qian
Published: March 2009

An effective, accurate and reliable HPLC with UV detection method was developed and validated for quantitation of six components: baicalin, berberine hydrochloride, quercetin, kaempferol, isorhamnetin and baicalein in intestinal perfusate using rotundin as an internal standard. The chromatographic separation was performed on a Welchrom‐C18 column (250 × 4.6 mm i.d. with 5.0 µm particle size) with a mobile phase consisting of acetonitrile, water, phosphoric acid and triethylamine (30:70:0.2:0.1,v/v) at a flow rate of 1.0 mL/min and a UV detection at 270 nm. The method had a chromatographic run time of 30 min and excellent linear behavior over the investigated concentration ranges observed with the values of r higher than 0.99 for all the analytes. The lower limit of quantification of the analytical method was 0.09 µg/mL for berberine hydrochloride, quercetin, kaempferol and baicalein and 0.18 µg/mL for baicalin and isorhamnetin. The intra‐ and inter‐day precisions measured at three concentration levels were all less than 10% for all analytes. The bias ranged from −6.91 to 4.33%. The validated method has been successfully applied to investigate the rat intestine absorption profiles of baicalin, berberine hydrochloride, quercetin, kaempferol, isorhamnetin and baicalein. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison of glucose/xylose cofermentation of poplar hydrolysates processed by different pretreatment technologies
Authors: Lu Yulin , Warner Ryan , Sedlak Miroslav , Ho Nancy , Mosier Nathan S.
Published: March 2009

The inhibitory effects of furfural and acetic acid on the fermentation of xylose and glucose to ethanol in YEPDX medium by a recombinant Saccharomyces cerevisiae strain (LNH‐ST 424A) were investigated. Initial furfural concentrations below 5 g/L caused negligible inhibition to glucose and xylose consumption rates in batch fermentations with high inoculum (4.5–6.0 g/L). At higher initial furfural concentrations (10–15 g/L) the inhibition became significant with xylose consumption rates especially affected. Interactive inhibition between acetic acid and pH were observed and quantified, and the results suggested the importance of conditioning the pH of hydrolysates for optimal fermentation performance. Poplar biomass pretreated by various CAFI processes (dilute acid, AFEX, ARP, SO2‐catalyzed steam explosion, and controlled‐pH) under respective optimal conditions was enzymatically hydrolyzed, and the mixed sugar streams in the hydrolysates were fermented. The 5‐hydroxymethyl furfural (HMF) and furfural concentrations were low in all hydrolysates and did not pose negative effects on fermentation. Maximum ethanol productivity showed that 0–6.2 g/L initial acetic acid does not substantially affect the ethanol fermentation with proper pH adjustment, confirming the results from rich media fermentations with reagent grade sugars. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Substance misuse amongst young people in non‐school settings: challenges to practitioners and policy makers
Authors: McCrystal Patrick
Published: March 2009

Over the past two decades the levels of substance misuse amongst children and young people have increased at a global level generally and within the UK in particular. Some school aged young people are considered to be at an increased risk to substance misuse, particularly those outside mainstream school. However, the literature on substance use by these young people remains comparatively limited. This paper explores this issue through an investigation of cannabis use trends amongst the High Risk Booster Sample of the Belfast Youth Development Study, a longitudinal study of adolescent substance use. It focuses upon the cannabis use patterns of young people excluded from school and those attending Emotional and Behavioural Difficulty units from the age of 11–16 years, groups who are historically categorised as vulnerable to substance misuse. The experience of these young people provides evidence to highlight the contemporary challenges facing policy makers and practitioners when addressing substance use and misuse use amongst these young people. Copyright © 2009 John Wiley & Sons, Ltd.
X‐Ray Structure Investigation of (20S)‐20‐O‐β‐D‐Glucopyranosyl‐protopanaxadiol and Antitumor Effect on Lewis Lung Carcinoma in vivo
Authors: Zhou Wei , Feng Meiqing , Li Xinwei , Yan Qin , Zhou Chaoqun , Li Jiyang , Zhou Pei
Published: March 2009

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(20S)‐20‐O‐β‐D‐Glucopyranosyl‐protopanaxadiol (1) has been isolated as a metabolite of ginseng saponins by Paecilomyces bainier. The compound crystallizes in the monoclinic space group P21 with unit cell parameters a=11.523(6) Å, b=12.383(6) Å, c=14.233(7) Å, β=96.862(9)°, and Z=2. The crystal structure has been solved by direct methods and refined to R=0.0536 for 4569 observed reflections. In the crystal structure, the water and methanol molecules link the molecules into infinite supramolecular layers through hydrogen bonds. The antitumor property of 1 was tested in vivo towards the inhibition of Lewis lung carcinoma growth. The results indicated that the antitumor effect of 1 was ordinary on monotherapy. However, comparing the antitumor activity of 1 plus cyclophosphamide (CTX) with that of CTX alone, the combination effect was significantly superior and synergistic. This may due to immunoloregulation activity of 1 by improving the WBC, IL‐2 and INF‐γ degraded by CTX.
Secondary Metabolites in Bryophytes: An Ecological Aspect
Authors: Xie Chun‐Feng , Lou Hong‐Xiang
Published: March 2009

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Bryophytes frequently grow in an unfavorable environment as the earliest land plants, and inevitably biosynthesize secondary metabolites against biotic or abiotic stress. They not only defend against the plant competition, microbial attack, and insect or animal predation, but also function in UV protection, drought tolerance, and freezing survival. This review covers the ecological aspect of secondary metabolites in bryophytes and is taxonomically presented according to the ecological significances.
Screening of Volatile Composition of Lavandula hybridaReverchon II Honey Using Headspace Solid‐Phase Microextraction and Ultrasonic Solvent Extraction
Authors: Jerković Igor , Marijanović Zvonimir
Published: March 2009

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The volatiles of unifloral Lavandula hybrida Reverchon II honey were isolated by means of headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE) and analyzed by gas chromatography and mass spectrometry (GC, GC/MS). A total of 23 compounds were identified in the headspace with hexan‐1‐ol, hexanal, acetic acid, hotrienol, and 2‐phenylacetaldehyde as the principal components. Three solvents of different polarity were used for USE, and a total of 53 compounds were identified. The extracts with pentane/Et2O 1 : 2 (v/v) were the most representative for USE method containing the majority of the honey floral origin compounds and potential biomarkers (hexanol, acetic acid, butane‐1,3‐diol, butane‐2,3‐diol, benzoic acid, coumarin, and 2‐phenylacetic acid). The total number of identified compounds (USE and HS‐SPME) was 59. In general, the comparison with volatiles of other lavandin honeys of different geographic origins indicated several similarities, while acetic and formic acids were identified with high percentages in L. hybrida Reverchon II honey.
Cellular Automata Models of the Influences on Solute Diffusion through Water
Authors: Kier Lemont B. , Cheng Cho‐Kun , Nelson Jean D.
Published: March 2009

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A cellular automata (CA) model of liquid water has been used to study self‐diffusion and the diffusion of a solute. The influences of temperature and solute hydropathic state are modeled as variables in this process. The self‐diffusion model correlates very well with earlier experimental data. The diffusion of a solute experiences variation with temperature and its hydropathic states. These influences are found to relate to models of free hydroxy groups and the average cavity cluster size in bulk water. These preliminary models serve as the basis for modeling solute diffusion for specific contaminants of interest (such as heavy metals like uranium) in a water system, and addressing its migration patterns with water relative to temperature.
Simulations in Evolution. II. Relative Fitness and the Propagation of Mutants
Authors: Testa Bernard , Bojarski Andrzej J.
Published: March 2009

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In Neo‐Darwinism, variation and natural selection are the two evolutionary mechanisms which propel biological evolution. Our previous article presented a histogram model [1] consisting in populations of individuals whose number changed under the influence of variation and/or fitness, the total population remaining constant. Individuals are classified into bins, and the content of each bin is calculated generation after generation by an Excel spreadsheet. Here, we apply the histogram model to a stable population with fitness F1=1.00 in which one or two fitter mutants emerge. In a first scenario, a single mutant emerged in the population whose fitness was greater than 1.00. The simulations ended when the original population was reduced to a single individual. The histogram model was validated by excellent agreement between its predictions and those of a classical continuous function (Eqn. 1) which predicts the number of generations needed for a favorable mutation to spread throughout a population. But in contrast to Eqn. 1, our histogram model is adaptable to more complex scenarios, as demonstrated here. In the second and third scenarios, the original population was present at time zero together with two mutants which differed from the original population by two higher and distinct fitness values. In the fourth scenario, the large original population was present at time zero together with one fitter mutant. After a number of generations, when the mutant offspring had multiplied, a second mutant was introduced whose fitness was even greater. The histogram model also allows Shannon entropy (SE) to be monitored continuously as the information content of the total population decreases or increases. The results of these simulations illustrate, in a graphically didactic manner, the influence of natural selection, operating through relative fitness, in the emergence and dominance of a fitter mutant.
Balloon dilation of pulmonary valve stenosis in infants less than 3 kg: A 20‐year experience
Authors: Karagoz Tevfik , Asoh Kentaro , Hickey Edward , Chaturvedi Rajiv , Lee Kyong‐Jin , Nykanen David , Benson Lee
Published: March 2009

Objectives: This study focused on the anatomical features and outcomes of percutaneous pulmonary valve balloon dilation (PVD) in newborns ≤3 kg in weight. Background: Although PVD is the treatment of choice for isolated pulmonary valve stenosis, there are no studies detailing technical, anatomical, and outcome variables in the smallest of infants undergoing the procedure. Methods: A retrospective, consecutive review of all initial and follow‐up echocardiograms, catheterization data, cineangiograms, and surgical records of all neonates less than 3 kg. Results: Fifty infants underwent 55 PVD's, median age 7 days and weight 2.7 kg. Congestive heart failure and/or cyanosis were present in 55%, 46% prostaglandin dependent, with 28% having a hypoplastic right ventricle. The pulmonary valve diameter median z‐score was −2.6, (range −5.8 to 1.2, P < 0.0001 vs. normal). The procedure was accomplished in all but one child, using a balloon to annulus ratio of 1.3 (range 1.1 to 1.7). There was a reduction in both the peak right ventricular systolic pressure (P < 0.0001) and outflow gradient (P < 0.0001). There was no procedure related mortality, although six children died in long‐term follow‐up (14%). Reintervention was necessary in 15 infants within 8 months of the procedure. Pulmonary regurgitation, present in 36% after the procedure, showed a gradual increase over time while outflow gradients decreased and valve annular dimensions increased toward normal. Conclusions: In infants ≤3 kg, PVD is safe and effective. A large proportion remains free from surgery (76% at 10 years). Small valve annular dimensions show catch up growth with time. © 2009 Wiley‐Liss, Inc.
Radial versus femoral approach for high‐speed rotational atherectomy
Authors: Watt Jonathan , Oldroyd Keith G.
Published: March 2009

Objective: The aim of this study was to compare in‐hospital outcomes for patients undergoing high‐speed rotational atherectomy (HSRA) via the radial and femoral route. Background: Transradial access is often avoided for HSRA because of concern over limitations on guide catheter size. No studies have compared a radial and femoral approach for HSRA. Methods: This is a retrospective comparison of in‐hospital outcomes for 151 consecutive patients (75 radial, 76 femoral) undergoing HSRA. Results: Significantly smaller diameter guide catheters (6.3 ± 0.5 Fr vs. 7.1 ± 0.8 Fr, P < 0.001) and burrs (1.6 ± 0.2 mm vs. 1.7 ± 0.2 mm, P = 0.02) were used in the radial compared with the femoral group. Procedural success (93.3% vs. 94.7%, P = 0.75), procedure time (108.7 ± 30.5 min vs. 112.8 ± 35.0 min, P = 0.45), and patient radiation exposure (12125 ± 8373 vs. 12118 ± 7831 cGy cm2, P = 1.00) were similar in radial and femoral groups. There was a trend in favor of radial artery access for major access site bleeding complications (0.0% vs. 5.3%, P = 0.12). The incidence of in‐hospital death or myocardial infarction was low in both groups. Conclusion: This study shows that radial artery access is a feasible, safe, and effective approach for HSRA. Overall complication rates are low and radial access may be associated with a lower risk of major bleeding complications compared with a femoral approach. © 2009 Wiley‐Liss, Inc.
Semipreparative HPLC enantioseparation, chiroptical properties, and absolute configuration of two novel cyclooxygenase‐2 inhibitors
Authors: Cirilli Roberto , Fiore Stefano , La Torre Francesco , Maccioni Elias , Secci Daniela , Sanna Maria Luisa , Faggi Cristina
Published: March 2009

A direct semipreparative HPLC enantioseparation of two chiral thiazolidinone derivatives having cyclooxygenase‐2 inhibition activity was performed on the Chiralpak IA chiral stationary phase. Semipreparative amounts of enantiopure forms were collected using acetonitrile‐ethanol‐trifluoroacetic acid mixtures as mobile phase. The absolute configuration of both compounds was unequivocally established by single‐crystal X‐ray diffraction method and correlated to the chiroptical properties of isolated enantiomers. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Estimation of thermodynamically consistent reaction rate coefficients
Authors: Anselmo Kenneth J. , Upadhye Ravindra S.
Published: March 2009

This note points out the importance of incorporating thermodynamic constraints in phenomenological models of cyclic reaction networks. We present a case study where the parameters of the postulated model are estimated with and without the necessary constraints, and show that ignoring the constraints can cause thermodynamically inconsistent parametric estimates.
Behavior of fine particles in a spouted bed consisting of fine and coarse particles
Authors: Ishikura T. , Shinohara H. , Tanaka I.
Published: March 2009

The elutriation of fines from a spouted bed of fine and coarse particles has been studied. Equations for correlating elutriation rate coefficients are proposed. Three different regions associated with particle behavior have been identified in a way to permit calculation of elutriation rate at any column height. Measurements of cross‐sectionally averaged holdup of particles and local particle velocity have been used to interpret the decrease in elutriation rate along the freeboard. The known concept of a Transport Disengaging Height (T.D.H.) has been employed.
Differential thermal analysis of reaction kinetics in pseudo‐isothermal state Part 1. Simple reaction
Authors: Matsuda Hitoki , Goto Shigeo
Published: March 2009

A new method for the evaluation of kinetic parameters is proposed, in which differential thermal analysis (DTA) is carried out under psuedo‐isothermal conditions, that is, both sample and reference materials are not heated and the temperatures remain as isothermal as possible. The hydrolysis of acetic anhydride was used as a model of simple reaction for the DTA experiment. The kinetic parameters such as the rate constant, the heat of reaction and the activation energy, evaluated from the proposed method were in good agreement with those obtained from conventional titration measurements. Systematic errors in the rate constant evaluation are discussed in order to enable the kinetic parameters to be evaluated accurately.
Computation of the near‐optimal temperature and initiator policies for a batch polymerization reactor
Authors: Thomas Isabelle M. , Kiparissides Costas
Published: March 2009

Optimal control theory is applied to a batch polymerization reactor for PMMA to calculate the near‐optimal temperature and initiator policies that are required to produce a polymer with a desired final conversion, and desired number average and weight average molecular weights. The two‐point boundary value problem that results from the application of the Pontryagin minimum principle to the mathematical model of the reactor is solved by the discretization control method. According to this, the total reaction time is divided into N equal subintervals. It is assumed that the control variables remain constant in each interval and the Hamiltonian is minimized by a first‐order gradient technique. It is shown that the introduction of the “target set” concept, which is well suited to industrial practice, simplifies the numerical solution of the TPBV problem. Results of the simulations demonstrate the potential gains possible from the application of the optimal control theory to the batch polymerization of PMMA.
On the mechanism of hydrodeoxygenation of ortho substituted phenols
Authors: Furimsky E. , Mikhlin J.A. , Jones D.Q. , Adley T. , Baikowitz H.
Published: March 2009

Hydrodeoxygenation reactivities of four ortho‐substituted phenols and of the unsubstituted phenol were compared at 350°C in the presence of a cobalt molybdate catalyst. The order of reactivities was established as: tert‐butyl phenol >phenol >methyl phenol> ethyl phenol >dimethyl phenol.The order of resistance of phenolic rings to hydrogenation was observed as: dimethyl phenol methyl phenol >ethyl phenol >tert butyl phenol >phenol.
Evolutionary synthesis method of energy integrated distillation separation process
Authors: Muraki Masaaki , Hayakawa Toyohiko
Published: March 2009

A two‐stage evolutionary method is developed to synthesize an optimal energy integrated distillation separation process: the search of the separation sequence, and the introduction of energy integration to the given separation sequence. For the former an evolutionary procedure first generating initial separation sequences and then evolving them is developed. For the latter an evolutionary procedure, first indicating the direction of the evolution by the thermodynamic analysis and then estimating it based on the objective function, is developed. An example problem of a five‐component separation demonstrates the effectiveness of this proposed method.
Measurement of band emissivity of porous spheres at high temperatures
Authors: Barua S. K. , Wynnyckyj J. R. , Rankin W. J.
Published: March 2009

A relatively simple technique has been developed to measure the band emissivity of spherical solids at high temperatures. The technique involves measuring the surface temperature of a sphere when in thermal equilibrium with a furnace enclosure, followed by isolating it from the enclosure by means of a shield. The emissivity is evaluated from the drop in energy flux from the pellet consequent upon changing the enclosure from an effectively black‐body to a freely radiating one. The value of the band emissivity is validated by simulating the experimental cooling curve using independently measured values of the effective thermal conductivity and total emissivity of the solid to obtain internal consistency. In this way highly accurate values of band emissivity are obtained.

The technique was applied to pellets of both reacted and unreacted mixtures of calcined‐dolomite and silicon, as used in the commercial production of magnesium.
Effect of gas sparging on the rate of mass transfer at fixed beds of horizontally stacked screens
Authors: Katkout F. A. , Zatout A. A. , Farag H. A. , Sedahmed G. H.
Published: March 2009

Rates of mass transfer at air sparged fixed beds of stacked screens were measured by an electrochemical technique. Variables studied were air superficial velocity, physical properties of the solution and bed thickness. The liquid mass transfer coefficient was found to increase with air superficial velocity up to a certain point and then remain almost constant with further increase in velocity. The increase in the mass transfer coefficient as a result of air sparging ranged from 2.8 to 10 times the natural convection value depending on the operating conditions. Increasing bed thickness was found to decrease the mass transfer coefficient at a given air superficial velocity. Mass transfer data at fixed beds were correlated by the equation:

j = 0.268 (Re · Fr)−0.25 (L/d)−0.35.

For a single horizontal screen the data were correlated by the equation:

j = 0.275 (Re · Fr)−0.21.
A Simple quasi‐steady analysis of turbulent flow freezing transients and comparison with experiments
Authors: Thomason S. B. , Mulligan J. C. , Hill J. M.
Published: March 2009

A simple quasi‐steady analysis is developed to predict transient heat transfer and pressure drop as an internal turbulent flow freezes when tube‐wall temperature is suddenly lowered. Heat transfer correlations by Sparrow‐Hallman‐Siegel and Kays, and the Blasius friction relation are modified for this analysis. Experimental data are compared and reasonable agreement exists when relatively uniform tube‐wall temperatures existed in the experimental apparatus; and indications are that the ice was of minimal thickness under those conditions. Analytical predictions did not agree well with experiments when the tube‐wall temperatures in the apparatus exhibited significant nonuniformity, or when thick frozen shells existed.
Catalyst mixing in bubble column slurry reactors
Authors: Chidambaram M.
Published: March 2009

The reported experimental data of Pandit and Joshi (1984) on axial and radial steady‐state catalyst concentration in a semibatch bubble column slurry reactor is interpreted by the dispersion model. The elliptic partial differential equation with its associated boundary conditions is solved analytically for catalyst concentration by the method of separation of variables. The proposed model adequately fits the experimental data.
Free convection heat transfer over a horizontal plate at low prandtl number
Authors: Singh P. , Narayan K. A.
Published: March 2009

Boundary layer equations for free convection heat transfer along a semi‐infinite horizontal plate are derived by giving more importance to the energy equation. The equations are obtained for low Prandtl number and two separate polynomials are used to approximate the temperature and velocity profiles in these regions. The rate of heat transfer is compared with the available analytical and numerical results based on conventional boundary layer equations.
A magic angle spinning 27A1 NMR study of the adsorption of CL2 on γ‐alumina
Authors: Rohner Markus Ch. , Sharma Virendra K. , Richarz Werner
Published: March 2009

Magic angle spinning 27Al NMR studies of a γ‐alumina show that the proportion of octahedrally coordinated aluminum ions increases after the adsorption of gaseous chlorine. The relative increase of the octahedrally coordinated aluminum ions is greater at higher temperatures and occurs due to preferential conversion of the tetrahedrally coordinated aluminum ions in the surface.
Modelling of butene‐1 dehydrogenation in a fixed bed reactor — bed and pellet profiles
Authors: Acharya D. R. , Hughes R.
Published: March 2009

A homogeneous model incorporating the Dumez & Froment kinetics has been proposed for the butene‐1 dehydrogenation reaction over a commercial chromia‐alumina catalyst. The model predicts bed and pellet concentration and temperature profiles. While the temperature profiles obtained suggest a temperature minimum in the reactor, the pellet remains nearly isothermal. Under the condition used in this study, a series type of coke deposition is obtained. A comparison between experimental results obtained using the neutron attenuation technique and theoretical coke profiles reveals excellent agreement and confirms the validity of the model and the kinetics employed.
An improved two layer model for horizontal slurry pipeline flow
Authors: Gillies R. G. , Shook C. A. , Wilson K. C.
Published: March 2009

A model for predicting head losses for coarse‐particle or settling slurries has been obtained. Experimental data for isothermal flows of sand, gravel and coarse coal slurries in pipes of industrial scale have been used to obtain the correlations in the model.

The model differs from previous versions in the way it deals with the concentration of the lower layer and in the role ascribed to the finest (–74 μm) particles. The fraction of contact load, which contributes sliding friction at the pipe wall, is found to be primarily a function of the ratio of the mean flow velocity to the settling velocity of the mass median particle size in the (+74 μm) fraction. The correlations are restricted to mixtures containing less than 35% (+ 74 μm) particles by volume.
Evaluation of a hollow fiber oxygenator for use in bubble—free mammalian cell bioreactors
Authors: Kalogerakis Nicolas , Behie Leo A.
Published: March 2009

The oxygen transfer capabilities of a hollow fiber oxygenator for intended use in bubble‐free aerated bioreactors have been evaluated experimentally. The oxygenator (480 mL), which is the main component of an artificial heart/lung unit used routinely in cardiopulmonary bypass procedures, was assessed for use in a recycle stream to determine if the oxygen requirements in bubble‐free hybridoma cell bioreactors could be supported on a large scale. Oxygen transfer to simulated medium in a 15 L bioreactor was found to depend primarily on the liquid recirculation rate (1 to 5 L/min) and was not seriously affected by the air flowrate in the oxygenator (0.5 to 15 L/min). Based on the experimentally determined mass transfer coefficient across the membrane, it was found that the oxygenator could support a 100 L fermentor at an average cell density of 2xl06 cells/mL with a specific uptake rate of 4.8 mgO2/(109 cells ‐ h).Furthermore, if oxygen enriched air were to be used in the oxygenator, a single unit could support cell densities beyond 8xl06cells/mL in a 100 L working volume fermentor.
Hydrodynamics in down flow jet loop reactor
Authors: Velan M. , Ramanujam T. K.
Published: March 2009

Gas holdup and liquid circulation time were measured in a down flow jet loop reactor for air–water system. It was observed that the circulation time decreases with an increase in nozzle diameter, draft tube to column diameter ratio and liquid velocity. Th gas holdup increases with an increase in gas and liquid velocities. The optimum draft tube to column diameter ratio was found to be 0.438. Correlations for gas holdup and circulation time involving operational and geometrical variables are presented.
Continuous and oscillatory flow properties of concentrated coal/water suspensions
Authors: Lapasin Romano , Pricl Sabrina
Published: March 2009

A Theological characterization of coal/water suspensions has been carried out under continuous and oscillatory flow conditions. Shear stress ‐ shear rate data were correlated with the Shangraw‐Grim‐Mattocks (SGM) equation. The analysis of the SGM parameters indicated that a limiting concentration ϕ0 exists above which the suspensions exhibit plastic behavior and suggested that a strong particle aggregation still occurs at high rates of shear. Oscillatory flow tests revealed marked non‐linear viscoelastic properties and analogies were found between the continuous and oscillatory flow behaviors of the coal/water suspensions, particularly under limiting flow conditions.
The maximum spoutable bed heights of water‐spouted fine particle systems
Authors: Çeçen Ayşe
Published: March 2009

The maximum spoutable bed height of systems of fine glass spheres spouted with water is studied in a flat based, semi‐circular column of 80 mm diameter using glass spheres of diameters 0.300, 0.377, and 0.450 mm.

A new correlation is proposed to predict the maximum spoutable bed height in water spouted fine particle systems. The same correlation is suggested for use with air spouted fine particles larger than 0.5 mm. It is concluded that in fine particle systems the jet penetration is significantly lower than that in coarse particle systems. The influence of the column diameter on the maximum spoutable bed height is also decreased significantly compared to coarse particle systems. Data reported in the literature for other water spouted fine particle systems agree with the correlation proposed in this work.
Experimental studies on flow boiling in inclined tubes: In the regions encountered in solar collectors
Authors: Maddi M. K. , Rao D. P.
Published: March 2009

Flow boiling in inclined tubes is encountered in solar collectors, but there is no literature on inclined flow boiling on which to base their design. Experimental studies have been carried out on heat transfer, pressure drop and flow maps for flow boiling of water in a circular tube. The angle of inclination was varied from 0° to 90°. The inclination was found to influence the transport processes in the bubbly and the intermittent flow regimes. The correlation of Chen (1966) has been extended to correlate the heat‐transfer data to account for the angle of inclination. The Baroczy (1965) and the Lockhart‐Martinelli (1949) correlations were adapted to correlate the frictional pressure gradient in the inclined flow boiling. The observed flow patterns were presented as flow maps.
The solubility of hydrogen sulfide in mixtures of n‐Hexadecane and n‐Eicosane
Authors: Feng G.‐X. , Mather A. E. , Carroll J. J.
Published: March 2009

The solubility of hydrogen sulfide in mixtures of n‐hexadecane and n‐eicosane was measured at a temperature of 323 K (50°C) for three isobars at 1, 2 and 3 MPa. The solubility data show a maximum as a function of the hydrocarbon composition.
Effects of additives on oxidation characteristics of palm oil‐based trimethylolpropane ester in hydraulics applications
Authors: Alias Nor Halaliza , Yunus Robiah , Idris Azni , Omar Rozita
Published: March 2009

Hydraulic fluids represent one of the most important groups of industrial lubricants. Increasing attention to environmental issues drives the lubricant industry to choose vegetable‐based hydraulic fluids which are biodegradable as compared to mineral‐based fluids. However, the lubricating properties of vegetable oil, such as poor oxidative stability and high pour point, have hindered their use. In this study, trimethylolpropane ester, which was derived from palm‐based methyl ester, was used as the base hydraulic fluid. The purpose of the study was to determine the optimum formulation for palm oil‐based synthetic lubricants by using suitable additives that can improve the oxidative stability and viscosity in accordance with the standard regulations for hydraulic fluid applications. The oxidative stability of the oil was evaluated by total acid number (TAN) and viscosity tests. In general, base oil without additive began to degrade after 200 h. The formulated oil, on the other hand, was quite stable even after 800 h of operation. The best formulation was obtained using 1.0% of either additive A or additive B. Both TAN and viscosity values were found to increase with increasing heating temperature. Meanwhile, the results have also shown that additive A performs better than additive B. After 800 h of exposure, the final TAN value for the formulated oil was only at 0.32 as compared to 4.88 mg KOH/g for the oil without additive. However, the kinematic viscosity of the oil at 40 and 100 °C was almost unchanged as compared to the oil without additive.