bluuebunny/crossref_metadata_2025 huggingface dataset:
Ligand‐Free Copper‐Catalyzed Arylation of Imidazole and N,N′‐Carbonyldiimidazole, and Microwave‐Assisted Synthesis of N‐Aryl‐1H‐imidazoles
Authors: Yang Xiao‐Dong , Li Liang , Zhang Hong‐Bin
Published: August 2008

Microwave‐assisted arylation of 1H‐imidazoles and N,N′‐carbonyldiimidazole under ligand‐free copper‐mediated conditions in tetraethyl orthosilicate is reported. Valuable evidence for understanding of the Cu‐catalyzed mechanism of the Ullmann reaction is also presented.
Intramolecular Wittig Reaction: A New Synthesis of (S)‐Pyrrolam A
Authors: Majik Mahesh S. , Parameswaran Perunninakulath S. , Tilve Santosh G.
Published: August 2008

A straightforward synthesis of (S)‐pyrrolam A is described. The synthesis involves in situ generation of the phosphorane 3, followed by an intramolecular Wittig reaction to furnish (S)‐pyrrolam A.
Kopsine and Danuphylline Alkaloids from Kopsia. Biomimetic Partial Synthesis of Danuphylline B
Authors: Lim Kuan‐Hon , Low Yun‐Yee , Tan Guan‐Huat , Kam Toh‐Seok , Lim Tuck‐Meng
Published: August 2008

Two new indole alkaloids, 12‐methoxykopsine (6) and danuphylline B (7), were obtained from the leaf extract of the Malayan Kopsia species, K. arborea, and their structures established by spectroscopic analysis. An electrochemically‐mediated partial synthesis of the ring‐opened alkaloid, danuphylline B from the hexacyclic alkaloid, methyl N(1)‐de(methoxycarbonyl)chanofruticosinate was carried out.
Synthesis, Characterization, Thermal Decomposition, and Kinetic Studies of Binuclear Sulfur‐Coordinated Tungsten(V) Complexes with Piperidine‐1‐carbodithioate
Authors: Lozano Rafael , de Jesús Fernando , Cano de Santayana Mercedes , Lozano M. Carmen
Published: August 2008

We describe the synthesis, characterization by IR and electronic spectra, magnetic susceptibility measurements, analytical data, kinetic study by differential‐scanning calorimetry, and thermogravimetric analysis of the thermal decomposition under N2 of the adducts 2–7 with pyridine or substituted pyridines of bis(piperidine‐1‐carbodithioato‐κS,κS′)di‐μ‐thioxodithioxoditungsten(V) (1), to which the general formula [W2B2(pipCS2)2S2(μ‐S)2] is assigned (pipCS2=piperidine‐1‐carbodithioato and B=pyridine (py), 3‐methylpyridine (3‐Mepy), 4‐methylpyridine (4‐Mepy), 3,5‐dimethylpyridine (3,5‐Me2py), pyridin‐3‐amine (3‐pyNH2), and pyridin‐4‐amine (4‐pyNH2)). For the endothermic process of loss of the coordinated base B, we calculated activation energies with a method reported previously by us; the mechanism and pre‐exponential Arrhenius factor of this reaction were also determined. A relationship between the pyridines' basicity, IR and electronic spectral data, and activation energies was established.
Prediction of protein folding rates from primary sequences using hybrid sequence representation
Authors: Jiang Yingfu , Iglinski Paul , Kurgan Lukasz
Published: August 2008

The ability to predict protein folding rates constitutes an important step in understanding the overall folding mechanisms. Although many of the prediction methods are structure based, successful predictions can also be obtained from the sequence. We developed a novel method called prediction of protein folding rates (PPFR), for the prediction of protein folding rates from protein sequences. PPFR implements a linear regression model for each of the mainstream folding dynamics including two‐, multi‐, and mixed‐state proteins. The proposed method provides predictions characterized by strong correlations with the experimental folding rates, which equal 0.87 for the two‐ and multistate proteins and 0.82 for the mixed‐state proteins, when evaluated with out‐of‐sample jackknife test. Based on in‐sample and out‐of‐sample tests, the PPFR's predictions are shown to be better than most of other sequence only and structure‐based predictors and complementary to the predictions of the most recent sequence‐based QRSM method. We show that simultaneous incorporation of several characteristics, including the sequence, physiochemical properties of residues, and predicted secondary structure provides improved quality. This hybridized prediction model was analyzed to reveal the complementary factors that can be used in tandem to predict folding rates. We show that bigger proteins require more time for folding, higher helical and coil content and the presence of Phe, Asn, and Gln may accelerate the folding process, the inclusion of Ile, Val, Thr, and Ser may slow down the folding process, and for the two‐state proteins increased β‐strand content may decelerate the folding process. Finally, PPFR provides strong correlation when predicting sequences with low similarity. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Evidence for the involvement of prothymosin α in the spermatogenesis of the frog Rana esculenta
Authors: Ferrara Diana , Izzo Gaia , Liguori Lucia , d'Istria Michela , Aniello Francesco , Minucci Sergio
Published: August 2008

Prothymosin α (PTMA) is a small acidic protein abundantly and ubiquitously expressed in mammals and involved in different biological activities. Until now, its specific function in spermatogenesis has never been properly investigated. Recently, the isolation of a cDNA encoding for PTMA from the testis of the frog Rana esculenta has been reported: ptma transcript is highly expressed throughout the frog reproductive cycle, peaking in September/October, in concomitance with the germ cell maturation; it is specifically localized in the cytoplasm of primary and secondary spermatocytes and, at a lower level, in the interstitial compartment, in Leydig cells.

In this article we support the involvement of PTMA in the meiotic phases of frog spermatogenesis. The expression of ptma mRNA increases in the testis of frogs treated with the antiandrogen cyproterone acetate, which blocks the II meiotic division and induces an increase in SPC cysts; on the contrary, it highly decreases in the testis of animals kept at 4°C and treated with human corionic gonadotropin, in concomitance with the induced block of spermatogenesis and the disappearance of meiotic cells in the tubules. Furthermore, for the first time we have also evidenced by immunohistochemistry the expression of PTMA in the nuclei of secondary spermatocytes, spermatids, and spermatozoa, as well as in the cytoplasm of interstitial Leydig cells. Taken together our data suggest for an important role of PTMA in germ cell maturation and/or differentiation during R. esculenta spermatogenesis. J. Exp. Zool. 311A:1–10, 2009. © 2008 Wiley‐Liss, Inc.
Brain‐derived neurotrophic factor effects on oligodendrocyte progenitors of the basal forebrain are mediated through trkB and the MAP kinase pathway
Authors: Van't Veer Ashlee , Du Yangzhou , Fischer Tanya Z. , Boetig Deborah R. , Wood Melissa R. , Dreyfus Cheryl F.
Published: August 2008

Previous work has indicated that BDNF increases the differentiation of basal forebrain (BF) oligodendrocytes (OLGs) in culture through the mediation of trkB and the MAPK pathway (Du et al. [ 2006a, b] Mol. Cell. Neurosci. 31:366–375; J. Neurosci. Res. 84:1692–1702). In the present work, effects of BDNF on BF OLG progenitor cells (OPCs) were examined. BDNF increased DNA synthesis of OPCs, as assessed by thymidine and bromodeoxyuridine incorporation. Effects of BDNF on DNA synthesis were mediated through the trkB receptor and not the p75 receptor, as shown by inhibitors that block neurotrophin binding to the receptors and by the phosphorylation of trkB. TrkB can activate the mitogen‐ activated protein kinase (MAPK), phosphatidylinositol‐3 kinase (PI3‐K), and phospholipase C‐γ (PLC‐γ) pathways. BDNF elicited the phosphorylation of MAPK and Akt, a kinase downstream of PI3K, but not PLC‐γ in OPCs. Through the use of specific inhibitors to the MAPK and PI3‐K pathways, it was found that the MAPK pathway was responsible for the effect of BDNF on DNA synthesis. These data indicate that BDNF affects OPC proliferation and development through the mediation of trkB and the MAPK pathway. © 2008 Wiley‐Liss, Inc.
Regulation of the phosphoinositide‐3 kinase and mitogen‐activated protein kinase signaling pathways by progesterone and its reduced metabolites in the rat brain
Authors: Guerra‐Araiza Christian , Amorim Miguel A.R. , Pinto‐Almazán Rodolfo , González‐Arenas Aliesha , Campos Maria G. , Garcia‐Segura Luis M.
Published: August 2008

Several growth factors, such as vascular endothelial growth factor, brain‐derived neurotrophic factor, and insulin‐like growth factor‐I are involved in the actions of progesterone in the central nervous system. Previous studies in neuronal and glial cultures have shown that progesterone may regulate growth factor signaling, increasing the phosphorylation of extracellular‐signal regulated kinase (ERK) and the phosphorylation of Akt, components of the mitogen‐activated protein kinase (MAPK) and the phosphoinositide‐3 kinase (PI3K) signaling pathways, respectively. In this study, we have evaluated whether progesterone and its reduced metabolites, dihydroprogesterone and tetrahydroprogesterone, regulate PI3K and MAPK signaling in the brain of ovariectomized rats in vivo. Significant increases in the phosphorylation of ERK, in the expression of the catalytic (p110) and the regulatory (p85) subunits of PI3K and in the phosphorylation of Akt were observed in the hypothalamus, the hippocampus, and the cerebellum 24 hr after progesterone administration. Progesterone metabolites partially mimicked the effect of progesterone and had a stronger effect on MAPK and PI3K signaling in the hypothalamus than in the other brain regions. These findings suggest that progesterone regulates MAPK and PI3K signaling pathways in the central nervous system in vivo by direct hormonal actions and by mechanisms involving progesterone metabolites. © 2008 Wiley‐Liss, Inc.
Variability of extreme temperature and precipitation in Iran during recent decades
Authors: Rahimzadeh Fatemeh , Asgari Ahmad , Fattahi Ebrahim
Published: August 2008

We examined extreme temperature and precipitation as indicative climatic variables to determine recent climatic changes over Iran. We present the results from 27 synoptic stations which have been quality controlled, tested for homogeneity and have less missing data. For each station, 27 indicative climatic indices recommended by the joint World Meteorological Organization CCL/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI) were calculated.

Marked negative trends for indices like frost days (FD), ice days (ID), cool days (TX10p), cool nights (TN10p) and diurnal temperature range (DTR) were found over most regions of Iran. Conversely, positive trends were found for summer days (SU25), warm days (TX90p) and tropical nights (TR20) over most regions of the country. For indices such as Cold Spell Duration Index (CSDI) and Warm Spell Duration Index (WSDI), both positive and negative trends were obtained.

We found negative trends in consecutive dry days (CDD) over most of the country. A negative trend was observed for about two‐thirds of the country for annual total wet days precipitation (PRCPTOT). Positive trends in the Simple Daily Intensity Index (SDII) were found for the northern half of the country, and concurrently negative trends in total wet days for many places within the same region. We observed a negative trend in very wet days exceeding the 95th percentile (R95p) over the eastern and western regions, and a positive trend over the central region of the country, although a clear negative trend was observed for extremely wet days exceeding the 99th percentile (R99p) over most of the country. No similar trends in either the maximum 1‐day precipitation (Rx1DAY) or maximum 5‐day precipitation (Rx5DAY) were found over the country. Copyright © 2008 Royal Meteorological Society
Modes of periacetabular load transfer to cortical and cancellous bone after cemented versus uncemented total hip arthroplasty: A prospective study using computed tomography‐assisted osteodensitometry
Authors: Mueller Lutz Arne , Schmidt Rainer , Ehrmann Cornelia , Nowak Tobias Eckhard , Kress Alexander , Forst Raimund , Pfander David
Published: August 2008

Stress‐shielding and periprosthetic bone loss after total hip arthroplasty (THA) may be clinically relevant for high‐demand patients. Analysis of cortical and cancellous bone density (BD) changes in vivo after THA is of interest to basic science researchers and joint reconstruction surgeons. An insufficient periprosthetic bone stock may predispose to migration, early mechanical failure, and major problems in revision surgery. We used computed tomography (CT)‐assisted osteodensitometry in two prospectively analyzed cohorts after cemented (n = 21) versus noncemented (n = 23) cup fixation. Periacetabular BD (mgCaHa/mL) was determined in five CT scans cranial and five CT scans at the level of the cup 10 days and 26 months postoperatively. For press‐fit cups BD decreased significantly in all CT cans except in four out of the five scans of cortical bone cranial to the cup. The decrease was highest for cancellous bone ventral to the cup (−45 to −53%). After cemented cup fixation, significant cortical BD decrease was seen ventral to the cup (−11 to −20%). Cancellous BD decrased only ventral (−21 to −31%) and in two scans cranial (−11 and −12%) to the cup. The modes of load transfer between cemented and uncemented cups differ fundamentally. Cemented cups especially prevent the loss of cancellous bone of the acetabulum while also cortical BD loss was significantly lower in most CT scans surrounding the cemented cup compared to the press‐fit component. Long‐term results are required to prove whether third‐generation cementing technique protects periprosthetic BD and thereby improve implant survival. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:176–182, 2009
Coccolithophores as palaeoecological indicators for shifts of the ITCZ in the Cariaco Basin during the late Quaternary
Authors: Mertens Kenneth N. J. M. , Lynn Matt , Aycard Mylene , Lin Hui‐Ling , Louwye Stephen
Published: August 2008

Coccoliths were studied from the ODP Hole 1002C and core PL07‐39PC in the Cariaco Basin. Increases in Emiliania huxleyi are synchronous with decreases of Gephyrocapsa oceanica and vice versa. A new index (GEX) based on the relative abundances of these two taxa is proposed, and correlates with various other proxies. It is shown that GEX can serve as upwelling proxy. This confirms that the Intertropical Convergence Zone shifted north during the Bølling/Allerød, south during the Younger Dryas and back north during the Preboreal. The upwelling proxy shows few discrepancies with the terrigenous record. Copyright © 2008 John Wiley & Sons, Ltd.
Sequential real number computation and recursive relations
Authors: Marcial‐Romero J. Raymundo , Moshier M. Andrew
Published: August 2008

In the first author's thesis [10], a sequential language, LRT, for real number computation is investigated. That thesis includes a proof that all polynomials are programmable, but that work comes short of giving a complete characterization of the expressive power of the language even for first‐order functions. The technical problem is that LRT is non‐deterministic. So a natural characterization of its expressive power should be in terms of relations rather than in terms of functions. In [2], Brattka examines a formalization of recursive relations in the style of Kleene's recursive functions on the natural numbers. This paper is an expanded version of [13] which establishes the expressive power of LRTp, a variant of LRT, in terms of Brattka's recursive relations. Because Brattka already did the work of establishing the precise connection between his recursive relations and Type 2 Theory of Effectivity, we thus obtain a complete characterization of first‐order definability in LRTp. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entwicklung von Tyrosinkinase‐Inhibitoren bei hämatologischen Neoplasien. FLT3 und JAK2 als therapeutische Targets
Authors: Lipka Daniel , Heidel Florian , Huber Christoph , Fischer Thomas
Published: August 2008

Tyrosinkinase‐Inhibitoren stellen einen wichtigen Beitrag zur Weiterentwicklung und Verbesserung der Therapie von hämatologischen Neoplasien dar. Zahlreiche Inhibitoren befinden sich bereits in fortgeschrittener klinischer Testung. Während bei einem Teil der Erkrankungen (CML) die Inhibitor‐Therapie bereits als Standard etabliert ist, befinden sich die “small molecules” bei Akuter Myeloischer Leukämie und chronisch‐myeloproliferativen Syndromen noch in der Etablierungsphase. Die Entwicklung von neuen zielgerichteten Substanzen zählt zu den großen präklinischen und klinischen Herausforderungen der nächsten Jahre.
Innovationen mit systemsprengendem Potenzial? Neue Wirkstoffe mit hohen Preisen
Authors: Pfannkuche Matthias S. , Glaeske Gerd
Published: August 2008

Die innovativen Tyrosinkinase‐Inhibitoren haben den therapeutischen “Wirkstoffschatz” sinnvoll erweitert, sind allerdings auch mit Preisen verbunden, die ein systemsprengendes Potenzial aufweisen. Für die zukünftige Finanzierbarkeit solcher Innovationen sind geeignete Strategien zu diskutieren.
Neue Therapieansätze bei Cystischer Fibrose
Authors: Vestner Anne , Schrepfer Barbara , Kockler Jutta , Mohr Franziska , Zündorf Ilse , Dingermann Theo
Published: August 2008

Cystische Fibrose ist mit einer Inzidenz von 1/2.500 bis 1/1.600 die häufigste autosomal‐rezessive Erbkrankheit in Mittel‐ und Nord‐Europa. Ungefähr jeder Zwanzigste ist Träger eines defekten Allels. Mutiert ist dabei das CFTR‐Gen (Cystic Fibrosis Conductance Transmembrane Regulator), das sich auf Chromosom 7 befindet.
Design of new polypropylene–woodflour composites: Processing and physical characterization
Authors: Bouza R. , Pardo S.‐G. , Barral L. , Abad M.J.
Published: August 2008

Woodflour/polypropylene composites were prepared with 10 and 20% in weight of woodflour (WF). The influence of the WF, the compatibilizer, and processing aid (WP) in the crystalline structure of the polypropylene was studied by thermal analysis. The results showed that the WF acts as a nucleating agent, increasing the crystallization rate of the PP at the cooling rates studied. The morphological study by SEM proved that the WP increased the dispersion of the filler into the PP matrix, and the ionomer, used like compatibilized improved the adhesion between the PP and the filler obtaining a more uniform morphology. The mechanical properties indicated that the incorporation of the ionomer and the WP enhanced the ductility of the composites at the same time that the materials reached a more uniform morphology. The amount of additives (compatibilizer and WP) included in the woodflour‐plastic composite (WPC) formulations was small, for this, the formulations are suitable to use in a possible industrial application. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Vitreous proteomic analysis of proliferative vitreoretinopathy
Authors: Yu Jing , Liu Feng , Cui Shu‐Jian , Liu Yan , Song Zheng‐Yu , Cao Hui , Chen Feng‐E , Wang Wei‐Jun , Sun Tao , Wang Fang
Published: August 2008

Proliferative vitreoretinopathy (PVR) is the most common cause of anatomic failure in retinal detachment surgery. To understand the molecular mechanisms, vitreous proteomes of patients with PVR were investigated by two‐dimensional‐nano‐liquid chromatography coupled with tandem mass spectrometry. Vitreous samples of moderate PVR (grade B), and severe PVR (grade C or D) were aspirated during pars plana vitrectomy before infusion. In the current study, 129, 97 and 137 proteins were identified in vitreous of normal control, moderate and severe PVR, respectively. In PVR vitreous samples, complement components, serine proteinase inhibitors, and extracellular proteins were up‐regulated or appeared, while normal cytoskeleton and metabolism proteins were down‐regulated or disappeared. It was noteworthy that the proteins involved in transcription and translation regulation increased in vitreous with PVR. Among 102 PVR‐specific proteins, kininogen 1 was specifically detected in both vitreous and the corresponding serum. Therefore, it can be concluded that PVR is a complicated pathology process with great amount of proteins involved in metabolism dysfunction, immune reactions, and cytoskeleton remolding. Kininogen 1 may be a candidate biomarker of PVR. Further investigations of these special proteins will provide additional targets for treatment or prevention of ocular proliferative diseases.
Comparative proteomic study of arsenic‐induced differentially expressed proteins in rice roots reveals glutathione plays a central role during As stress
Authors: Ahsan Nagib , Lee Dong‐Gi , Alam Iftekhar , Kim Pil Joo , Lee Jeung Joo , Ahn Young‐Ock , Kwak Sang‐Soo , Lee In‐Jung , Bahk Jeong Dong , Kang Kyu Young , Renaut Jenny , Komatsu Setsuko , Lee Byung‐Hyun
Published: August 2008

While the phytotoxic responses of arsenic (As) on plants have been studied extensively, based on physiological and biochemical aspects, very little is known about As stress‐elicited changes in plants at the proteome level. Hydroponically grown 2‐wk‐old rice seedlings were exposed to different doses of arsenate, and roots were collected after 4 days of treatment, as well as after a recovery period. To gain a comprehensive understanding of the precise mechanisms underlying As toxicity, metabolism, and the defense reactions in plants, a comparative proteomic analysis of rice roots has been conducted in combination with physiological and biochemical analyses. Arsenic treatment resulted in increases of As accumulation, lipid peroxidation, andin vivoH2O2contents in roots. A total of 23 As‐regulated proteins including predicted and novel ones were identified using 2‐DE coupled with MS analyses. The expression levels ofS‐adenosylmethionine synthetase (SAMS), GSTs, cysteine synthase (CS), GST‐tau, and tyrosine‐specific protein phosphatase proteins (TSPP) were markedly up‐regulated in response to arsenate, whereas treatment by H2O2also regulated the levels of CS suggesting that its expression was certainly regulated by As or As‐induced oxidative stress. In addition, an omega domain containing GST was induced only by arsenate. However, it was not altered by treatment of arsenite, copper, or aluminum, suggesting that it may play a particular role in arsenate stress. Analysis of the total glutathione (GSH) content and enzymatic activity of glutathione reductase (GR) in rice roots during As stress revealed that their activities respond in a dose‐dependent manner of As. These results suggest that SAMS, CS, GSTs, and GR presumably work synchronously wherein GSH plays a central role in protecting cells against As stress.
Combining “click” chemistry and step‐growth polymerization for the generation of highly functionalized polyesters
Authors: Billiet Leen , Fournier David , Du Prez Filip
Published: August 2008

Aliphatic polyesters bearing pendant alkyne groups were successfully prepared by step‐growth polymerization of different building blocks such as adipic acid and succinic acid in combination with an acetylene‐based diol, 2‐methyl‐2‐propargyl‐1,3‐propanediol, besides 1,4‐butanediol and ethylene glycol. It was demonstrated that the alkyne groups survive the high reaction temperatures (200 °C) in the presence of a radical inhibitor. The alkyne loading has been tuned by the ratio of the different monomers used, up to 25 mol % of alkyne groups. Subsequently, the alkyne groups have been reacted with azides by the copper‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction, a popular type of “click” chemistry. “Click” reactions have been performed quantitatively in the presence of benzyl azide and azide‐terminated poly(ethylene glycol), yielding brush copolymers in the latter case. Kinetic investigations about this click reaction have been performed by means of on‐line Fourier transform mid‐infrared spectroscopy, which was reported for the first time in the field of the click chemistry research. A whole range of functionalized polyesters, based on poly(ethylene succinate) and poly(butylene adipate), is available, the properties of which can be tailored by choosing the appropriate azide compound. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6552–6564, 2008
Unexpected reactions associated with the xanthate‐mediated polymerization of N‐vinylpyrrolidone
Authors: Pound Gwenaelle , Eksteen Zaskia , Pfukwa Rueben , McKenzie Jean M. , Lange Ronald F. M. , Klumperman Bert
Published: August 2008

The monomer N‐vinylpyrrolidone (NVP) undergoes side reactions in the presence of R group functional xanthates and impurities. The fate of the monomer NVP and a selection of six O‐ethyl xanthates during xanthate‐mediated polymerization were studied via NMR spectroscopy. A high number of by‐products were identified. Significant side reactions affecting NVP include the formation of an unsaturated dimer and hydration products in bulk or in solution in C6D6. In addition, the xanthate adjacent to a NVP unit was found to undergo elimination at moderate temperature (60–70 °C), resulting in unsaturated species and the formation of new xanthate species. The presence of the chlorinated compound α‐chlorophenyl acetic acid, ethyl ester, a precursor in the synthesis of the xanthate S‐(2‐ethyl phenylacetate) O‐ethyl xanthate, resulted in a dramatic increase in the rate of side reactions such as unsaturated dimer formation and a high ratio of unsaturated chain ends. The conditions for the occurrence of such side reactions are discussed in this article, with relevance to increasing the control over the polymerization kinetics, endgroup functionality, and control over the molar mass distribution. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6575–6593, 2008
Effect of temperature on the number of active sites and propagation rate constant at ethylene polymerization over supported bis(imino)pyridine iron catalysts
Authors: Barabanov Artem A. , Bukatov Gennady D. , Zakharov Vladimir A.
Published: August 2008

The inhibition of ethylene polymerization with radioactive carbon monoxide (14CO) was used to obtain data on the number of active sites (CP) and propagation rate constant (kP) at ethylene polymerization in the temperature range of 35–70 °C over supported catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 (L: 2,6‐(2,6‐(Me)2C6H3N = CMe)2C5H3N) with activator Al(i‐Bu)3. The values of effective activation energy (Eeff), activation energy of propagation reaction (EP), and temperature coefficients of variation of the number of active sites (ECp = Eeff − EP) were determined. The activation energies of propagation reaction for catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 were found to be quite similar (5.2–5.7 kcal/mol). The number of active sites diminished considerably as the polymerization temperature decreased, the ECp value being 5.2–6.2 kcal/mol for these catalysts at polymerization in the presence of hydrogen. The reactions of reversible transformations of active centers to the surface hydride species at polymerization in the presence and absence of hydrogen are proposed as the derivation of ECp. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6621–6629, 2008
Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide
Authors: Mujumdar Siddharthya K. , Siegel Ronald A.
Published: August 2008

pH‐sensitive nanoclay composite hydrogels based on N‐isopropylacrylamide (NIPA) were synthesized by copolymerization with cationic and anionic comonomers. Laponite nanoclay particles served as multifunctional crosslinkers, producing hydrogels with exceptionally high mechanical strengths, as measured by elongation at break. Cationic copolymer gels based on NIPA and dimethylaminoethylmethacrylate were prepared by aqueous free radical polymerization, adopting a procedure reported by Haraguchi (Adv Mater 2002, 14, 1120–1124). Without modification, this technique failed to produce anionic copolymer gels of NIPA and methacrylic acid (MAA), due to flocculation of clay particles. Three methods were conceived to incorporate acidic MAA into nanoclay hydrogels. First, NIPA was copolymerized with sodium methacrylate under dilute conditions, producing hydrogels with good pH‐sensitivity but weak mechanical characteristics. Second, NIPA was copolymerized with methyl methacrylate, which was then hydrolyzed to generate acid sidegroups, yielding hydrogels that were much stronger but less pH sensitive. Third, NIPA was copolymerized with MAA following modification of the nanoclay surface with pyrophosphate ions. The resulting hydrogels exhibited both strong pH‐sensitivities at 37 °C and excellent tensile properties. Optical transparency changed during polymerization, depending on hydrophobicity of the components. This work increases the diversity and functionality of nanoclay hydrogels, which display certain mechanical advantages over conventionally crosslinked hydrogels. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6630–6640, 2008
Preferential selection of Cys‐constrained peptides from a random phage‐displayed library by anti‐glucitollysine antibodies
Authors: Rojas Gertrudis , Pupo Amaury , Aleman Maria Del Rosario , Vispo Nelson Santiago
Published: August 2008

Phage‐displayed peptides recognized by two monoclonal antibodies against glucitollysine were selected. The most prominent feature of the peptide panel was the presence of paired Cys in most of them (21/24 peptides). The availability of a wide variety of peptides having differently spaced paired Cys, as well as truly linear Cys‐free peptides, gave the opportunity to explore the role of disulfide bridges in phage selection. Some Cys‐containing peptides came from a Cys‐flanked cyclic 9‐mer library, but most of them (18/21) were derived from a totally random 12‐mer library, and hence the presence of Cys was dictated by the selector antibodies. Motifs shared by several peptides (potentially involved in binding) often contained or were flanked by Cys residues. Binding of all Cys‐containing phage‐displayed peptides was abolished/decreased after a reducing treatment. Screening a random peptide library (without invariant Cys residues) is powerful enough to clearly reveal the need, preferences, and diversity of Cys‐mediated structural constraints for recognition. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Identification of novel peptide agonists from a random peptide library for a 5‐oxo‐ETE receptor, a receptor for bioactive lipids
Authors: Sasaki Yoshinori , Tsujii Takashi , Takeda Shigeki , Obinata Hideru , Izumi Takashi , Yamada Keiichi , Katakai Ryoichi
Published: August 2008

A combinatorial peptide library contains an enormous combination of amino acid sequences and drug candidates, but an effective screening strategy to identify a variety of bioactive peptides has yet to be established. In this article, a random hexapeptide library was screened to identify novel peptide ligands for a 5‐oxo‐ETE receptor (OXER), which is a G‐protein‐coupled receptor for bioactive lipids, by using an OXER‐Gi1α fusion protein. We successfully identified 2 hexapeptides—Ac‐HMQLYF‐NH2and Ac‐HMWLYF‐NH2—that exhibited agonistic activity. Although the corresponding affinities were relatively low (EC50values of 146 and 6.7 µM, respectively), the activities were confirmed by other independent cell‐based assay methods, namely, intracellular calcium mobilization and cell chemotaxis. This study demonstrates that a combinatorial peptide library may be screened using a [35S]GTPγS binding assay with G‐protein‐coupled receptor (GPCR)–Gα fusion proteins, in general, and that of peptide ligands can be obtained even for nonpeptide receptors. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
A one‐year survey on the use of a powder from Rosa canina lito in acute exacerbations of chronic pain
Authors: Chrubasik C. , Wiesner L. , Black A. , Müller‐Ladner U. , Chrubasik S.
Published: August 2008

This pilot surveillance included 152 patients with acute exacerbations of chronic pain, 124 (Back group) with non‐specific low back pain (NSLBP), 20 with NSLBP overridden by osteoarthritic pain (Knee‐Hip group), and eight with specific LBP (included in the safety analysis). Patients were recommended the rose hip and seed powder LitozinR at a dose providing up to 3 mg of galactolipid/day for up to 54 weeks. Clinical symptoms and well‐being were assessed every 6 weeks. The patients also kept a diary of their pain and the requirement for rescue medication. Data were analysed by intention to treat with last observation carried forward.

Only 77 patients completed the year of surveillance. Multivariate analysis suggested an appreciable overall improvement during the surveillance, irrespective of group, and this was reflected for most of the individual measures in repeated measures ANOVA. The degree and time‐course of improvement echoed that seen in similar surveillances of patients receiving an aqueous extract of Harpagophytum. Multiple regression analyses indicated that percentage changes from baseline tended to be greater in patients with greater degrees of pain and disability, but were otherwise largely unrelated to the patients' characteristics. There were no serious adverse events.

The rose hip and seed powder, LitozinR, seems to deserve further, more definitive studies as a possible option in long‐term management of NSLBP with or without osteoarthritic pain. Copyright © 2008 John Wiley & Sons, Ltd.
Chemoprotective effects of a protein from the red algaePorphyra yezoensison acetaminophen‐induced liver injury in rats
Authors: Hwang Hye‐Jung , Kwon Mi‐Jin , Kim In‐Hye , Nam Taek‐Jeong
Published: August 2008

Seaweeds contribute to the maintenance of health through their nutritional and medicinal properties. The effects of PYP, a 14 kDa protein isolated from a hot‐water extract of the marine algaPorphyra yezoensis, on AAP‐induced liver injury in rats was evaluated. AAP induced acute liver injury and AAP‐induced hepatotoxicity is the leading cause of liver failure. In this study, male Sprague–Dawley rats were assigned to one of three treatment groups: control, AAP, or AAP + PYP. Compared with the control group, liver tissue from the AAP group showed increased levels of caspase‐3 activity and DNA fragmentation, decreased levels of GSH and increased serum GOT/GPT levels. In contrast, treatment with AAP + PYP produced levels of caspase‐3 activity, DNA fragmentation, GSH and GOT/GPT that matched the values seen in the control group. It is concluded that PYP may prevent AAP‐induced liver injury. Copyright © 2008 John Wiley & Sons, Ltd.
A direct and rapid leaf water extraction method for isotopic analysis
Authors: Peters L. I. , Yakir D.
Published: August 2008

Isotopic measurements of leaf water have provided insights into a range of ecophysiological and biogeochemical processes, but require an extraction step which often constitutes the major analytical bottleneck in large‐scale studies. Current standard procedures for leaf water analysis are based on cryogenic vacuum or azeotrophic distillation, and are laborious, require sophisticated distillation lines and the use of toxic materials. We report a rapid technique based on centrifugation/filtration of leaf samples pulverised in their original sampling tubes, using a specifically adapted, simple apparatus. The leaf water extracts produced are suitable for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new method was validated against cryogenic vacuum distillation and showed an overall accuracy of ±0.5‰ (nine grouped comparisons, n = 110) over a range of 21‰. Effects due to the presence of soluble carbohydrates were near the detection limits for most samples analysed, and these effects could be corrected for (the extracted soluble organics could also be used for isotopic analysis). The extraction time for a routine eight‐sample subset was reduced from 4 h (cryogenic distillation) to 45 min, limited only by the size of the centrifuge(s) used. This method provides a rapid, low‐cost and reliable alternative to conventional vacuum and other distillation methods that can alleviate current restrictions on ecosystem‐ and global‐scale studies that require high‐throughput leaf water isotopic analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Autofluorescence spectroscopy and imaging of Platymonas subcordiformis irradiated by diode laser based on LSCM
Authors: Huang Zufang , Chen Rong , Li Yongzeng , Zhuang Huiru , Chen Jianxin , Wang Lijiang
Published: August 2008

Autofluorescence spectra and optical imaging of Platymonas subcordiformis after irradiation of diode laser were observed via laser scanning confocal microscopy (LSCM). With 488 nm Ar+ laser excitation, the horizontal and vertical dimensions of a cup‐shaped chloroplast of the irradiation group increased about 10% compared with the control group. The fluorescence spectra were similar between irradiation group and control group with a maximum fluorescence band around 682 nm, whereas the former has a higher intensity. Image of a small circular substance with stronger two‐photon autofluorescence (TPA) was obtained when using two‐photon excitation wavelength of 800 nm in single‐channel mode. Further analysis by the 800 nm excitation based on two independent‐channels mode showed an emission band of the small circular substance around 376–505 nm, which corresponded to the eyespot of P. subcordiformis. In lambda scanning mode, with two‐photon wavelength of 800 nm excitation, six fluorescence peaks that are located at 465, 520, 560, 617, 660 and 680 nm were observed; the fluorescence intensity of the irradiation group was higher than that of the control group, especially at 520, 560 and 617 nm. As a conclusion, diode laser irradiation can promote chloroplast growth of P. subcordiformis cells in the form of expanding area and the increasing content of protein, phospholipids and chlorophyll. LSCM, especially TPA imaging based on femtosecond laser excitation, provides a nondestructive, real‐time and accurate method to study changes of living algal cells under laser irradiation and other environmental factors. SCANNING 30: 443–447, 2008. © 2008 Wiley Periodicals, Inc.
Bayesian adaptive model selection for optimizing group sequential clinical trials
Authors: Wathen J. Kyle , Thall Peter F.
Published: August 2008

This article presents a new approach to the problem of deriving an optimal design for a randomized group sequential clinical trial based on right‐censored event times. We are motivated by the fact that, if the proportional hazards assumption is not met, then a conventional design's actual power can differ substantially from its nominal value. We combine Bayesian decision theory, Bayesian model selection and forward simulation (FS) to obtain a group sequential procedure that maintains targeted false‐positive rate and power, under a wide range of true event time distributions. At each interim analysis, the method adaptively chooses the most likely model and then applies the decision bounds that are optimal under the chosen model. A simulation study comparing this design with three conventional designs shows that, over a wide range of distributions, our proposed method performs at least as well as each conventional design, and in many cases it provides a much smaller trial. Copyright © 2008 John Wiley & Sons, Ltd.
Seamlessly integrating similarity queries in SQL
Authors: Barioni M. C. N. , Razente H. L. , Traina A. J. M. , Traina C.
Published: August 2008

Modern database applications are increasingly employing database management systems (DBMS) to store multimedia and other complex data. To adequately support the queries required to retrieve these kinds of data, the DBMS need to answer similarity queries. However, the standard structured query language (SQL) does not provide effective support for such queries. This paper proposes an extension to SQL that seamlessly integrates syntactical constructions to express similarity predicates to the existing SQL syntax and describes the implementation of a similarity retrieval engine that allows posing similarity queries using the language extension in a relational DBMS. The engine allows the evaluation of every aspect of the proposed extension, including the data definition language and data manipulation language statements, and employs metric access methods to accelerate the queries. Copyright © 2008 John Wiley & Sons, Ltd.
Ten factors that impede improvement of verification and validation processes in software intensive organizations
Authors: García Javier , de Amescua Antonio , Velasco Manuel , Sanz Ana
Published: August 2008

In spite of the potential benefits that the correct application of software verification and validation processes, techniques and tools can provide, their institutionalized use in the software industry does not reach the minimum capability levels required to gain these benefits. Moreover, this circumstance is aggravated in the small and medium SIOs because of the lack of available human and economic resources.

In this paper, ten of the most important factors that prevent the correct institutionalization of the software verification and validation efficient practices are presented. These factors are obtained from the authors' experience in several software process improvement initiatives in software verification and validation processes. Copyright © 2008 John Wiley & Sons, Ltd.
Color modulation for intramolecular charge‐transfer‐induced chemiluminescence of 1,2‐dioxetanes
Authors: Matsumoto Masakatsu , Watanabe Nobuko , Hoshiya Naoyuki , Ijuin Hisako K.
Published: August 2008

Dioxetanes bearing an aromatic electron donor decompose with an accompanying emission of light by an intramolecular charge‐transfer‐induced chemiluminescence (CTICL) mechanism. The color of the chemiluminescence from CTICL‐active aryl‐substituted dioxetanes is controlled by the design of the aromatic moiety and its substitution pattern, and the substituent on the carbon of the dioxetane ring. In addition to these color modulations, a change in the conformation of dioxetanes bearing a biaryl group was also found to cause a change in the color of CTICL in the coordination sphere of a crown ether complex. This new color modulation system was further developed for optically active dioxetanes bearing 2‐hydroxy‐1,1′‐binaphthyl, the CTICL of which took place under the chiral recognition of optically active crown ether complexes. The spectra of the chemiluminescence from biaryl‐type dioxetanes did not coincide with the fluorescence spectrum from the authentic emitter in the coordination sphere, but they did coincide with each other in a completely homogeneous system. This finding suggests that the emitter of CTICL possesses a transient structure, which retains the afterimage of the conformation of the dioxetane. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 213–228; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20150
Optimization of transformer noise level by reverse calculation using linear programming
Authors: Tanaka Hideaki , Yamashita Daiki , Yokoyama Ryuichi
Published: August 2008

This paper proposes a simple and practical method of determination of optimal acoustic noise levels of transformers to be replaced in an aged substation. The proposed algorithm is based on linear programming using an empirical formula for estimating noise levels at the boundary points around the substation premises. Necessary input parameters are the three dimensions of each transformer and the distance between transformers and each boundary point. Constraints are derived from the empirical noise‐level estimation formula and the regulated noise levels at the boundary. An equivalent sum of transformer noise levels is selected as an objective function to be maximized. The proposed method was successfully tested on a model substation. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Dynamic ant programming for automatic construction of programs
Authors: Shirakawa Shinichi , Ogino Shintaro , Nagao Tomoharu
Published: August 2008

A new method for automatic programming is proposed in this paper. Automatic programming is the method of generating computer programs automatically. Genetic programming (GP) is a typical example of automatic programming. GP evolves computer programs with tree structure based on genetic algorithm (GA). The new method is named dynamic ant programming (DAP). DAP is based on ant colony optimization (ACO) and uses dynamically changing pheromone table. The nodes (terminal and nonterminal) are selected using the value of pheromone table. The higher the rate of pheromone, the higher is the probability that it can be chosen. Although the search space (i.e., the pheromone table of DAP) is dynamically changing, the ants find good solution using portions of solutions, which are of pheromone value. We describe the method of construction of tree structure using ACO, as well as pheromone update and deletion and insertion of nodes in detail. DAP is applied to the symbolic regression problem that is widely used as a test problem for GP system. We compare the performance of DAP to GP and show the effectiveness of DAP. In order to investigate the influence of several parameters, we compare experimental results obtained using different settings. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Ultrasonographic visualization of balloon placement for uterine tamponade in massive primary postpartum hemorrhage
Authors: Cho Y. , Rizvi C. , Uppal T. , Condous G.
Published: August 2008

This case report is the first documentation of ultrasonographic confirmation of positioning of a Sengstaken‐Blakemore balloon catheter (SBEC) in the management of massive postpartum hemorrhage. The sonongraphic position, while incorrect according to conventional use of uterine balloon catheters, raises the possibility of an alternative mechanism of action of the balloon: not uterine cavity tamponade but hydrostatic pressure directly around the uterine arteries, a mechanism akin to mechanical uterine artery embolization or ligation. If this hypothesis is correct, it not only elucidates how balloon tamponade works but also challenges current thinking on how postpartum hemorrhage should be managed effectively. Future studies are required to corroborate this hypothesis and we believe that sonographic confirmation of balloon catheter location should be an integral part of uterine balloon tamponade in women with massive primary postpartum hemorrhage. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of right pulmonary artery to left atrium communication
Authors: Rama Murthy B. S. , Krishna S. R. , Rao P. M.
Published: August 2008

We report a case of right pulmonary artery to left atrium communication in a fetus at 24 weeks' gestation. Fetal echocardiography showed dilatation of the left atrium and main and right pulmonary arteries. The right pulmonary artery was seen to communicate with the left atrium. Color Doppler velocimetry demonstrated high‐velocity flow through the communication. The pregnancy was terminated and findings were confirmed at autopsy. The embryological and postnatal aspects of right pulmonary artery to left atrium communication are discussed. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.