bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemiluminescence of ClO3−‐SO32−‐Rh6G‐SDBS System and Its Application to the Determination of Sulfite
Authors: Chen Xiang‐Lei , Zhao Li‐Xia , Lin Jin‐Ming 
Published: January 2006

AbstractBased on the micelle synergism mechanism, a chemiluminescence (CL) flow system for the determination of sulfite was described. The CL signal generated from the reaction of chlorate with sulfite in acidic solution was very weak, while the interfusion of sodium dodecylbenzenesulfonate (SDBS) resulted in a highly chemiluminescent intensity. The major goal of this work was to investigate and develop the SDBS micelle synergetic CL system. The mechanism was proposed and proved by spectrometry. The results indicated that the unique structure of SDBS micelles promoted the aggregation of rhodamine 6G (Rh6G) and a much easier energy transfer, leading to a marked shift to red in the CL emission. This CL system was developed for the determination of sulfite and the concentration of sulfite was proportional to the CL intensity in the range of 5.0×10−8–1.0×10−5 mol/L with the detection limit of 1.7×10−8 mol/L (S/N=3). The relative standard deviation was 3.3% for 1.0×10−6 mol/L sulfite solution with eleven repeated measurements. This method was successfully applied to the determination of sulfite in powder sugar.
A Rapid and Convenient Synthetic Route to Novel 1,5‐Benzodiazepine Derivatives of 5‐Methyl‐3‐phenyl‐2‐oxo‐Δ4‐1,3,4‐oxadiazolines from p‐Acetylphenylsydnone and Their Pharmacological Activity
Authors: Kamble Ravindra R. , SUDHA Belagur S. 
Published: January 2006

AbstractA simple and high yielding method for the integration of 1,5‐benzodiazepines integrated with 5‐methyl‐2‐oxo‐3‐phenyl‐Δ4‐1,3,4‐oxadiazolines in 75%–90% yield by microwave irradiation is devised. Microwave‐accelerated reaction was compared with thermal method. All the compounds were characterized by physical, analytical and spectral (IR, 1H NMR, MS) data. Title compounds were screened for preliminary pharmacological activities.
Resonance Light Scattering Imaging Detection of Single Suprahelical Species of DNA Induced by Porphine‐5,10,15,20‐tetrakis(p‐phenyltrimethylaminium)
Authors: Liu Xi‐Dong , Huang Cheng‐Zhi , Guo Hong‐Ping , Huang Yu‐Ming 
Published: January 2006

AbstractA resonance light scattering (RLS) imaging method was proposed based on imaging and measuring the RLS features of single suprahelical species of DNA, and its application to DNA assay was also investigated. In acidic medium, porphine‐5,10,15,20‐tetrakis(p‐phenyltrimethylaminium) (PTPTMA), could stack along the molecular surface of DNA with the mode of long‐range assembly to induce the formation of suprahelical species of DNA, resulting in strong RLS signals in the range of 450–510 nm. Under the excitation of 488 nm light beam of argon ion laser source, single suprahelical species could be observed with the aid of a common microscope due to the strong scattered light emitted by the suprahelical species. By capturing the RLS images of the single suprahelical species with a cooled charge coupled device (CCD) camera, and analyzing the RLS data, herein an RLS imaging method of DNA was proposed based on the linear relationship between the counts of suprahelical species in the detection focus plane and the concentration of DNA in nanograms. When 1.8??µmol/L PTPTMA was employed, both calf thymus DNA (ct DNA) and fish sperm DNA (fs DNA) in the range of 25–1100 ng/mL could be detected with the limits of detection lower than 25 ng/mL (3σ). Four synthetic samples were detected satisfactorily with relative standard deviations less than 5.1%.
An efficient memory operations optimization technique for vector loops on Itanium 2 processors
Authors: Jalby William , Lemuet Christophe , Touati Sid‐Ahmed‐Ali 
Published: January 2006

AbstractTo keep up with a large degree of instruction level parallelism (ILP), the Itanium 2 cache systems use a complex organization scheme: load/store queues, banking and interleaving. In this paper, we study the impact of these cache systems on memory instructions scheduling. We demonstrate that, if no care is taken at compile time, the non‐precise memory disambiguation mechanism and the banking structure cause severe performance loss, even for very simple regular codes. We also show that grouping the memory operations in a pseudo‐vectorized way enables the compiler to generate more effective code for the Itanium 2 processor. The impact of this code optimization technique on register pressure is analyzed for various vectorization schemes. Copyright © 2006 John Wiley & Sons, Ltd.
Incentive‐based scheduling in Grid computing
Authors: Zhu Yanmin , Xiao Lijuan , Xu Zhiwei , Ni Lionel M. 
Published: January 2006

AbstractWith the rapid development of high‐speed wide‐area networks and powerful yet low‐cost computational resources, Grid computing has emerged as an attractive computing paradigm. In typical Grid environments, there are two distinct parties, resource consumers and resource providers. Enabling an effective interaction between the two parties (i.e. scheduling jobs of consumers across the resources of providers) is particularly challenging due to the distributed ownership of Grid resources. In this paper, we propose an incentive‐based peer‐to‐peer (P2P) scheduling for Grid computing, with the goal of building a practical and robust computational economy. The goal is realized by building a computational market supporting fair and healthy competition among consumers and providers. Each participant in the market competes actively and behaves independently for its own benefit. A market is said to be healthy if every player in the market gets sufficient incentive for joining the market. To build the healthy computational market, we propose the P2P scheduling infrastructure, which takes the advantages of P2P networks to efficiently support the scheduling. The proposed incentive‐based algorithms are designed for consumers and providers, respectively, to ensure every participant gets sufficient incentive. Simulation results show that our approach is successful in building a healthy and scalable computational economy. Copyright © 2006 John Wiley & Sons, Ltd.
G‐PASS: an instance‐oriented security infrastructure for Grid travelers
Authors: Ma Tianchi , Chen Lin , Wang Cho‐Li , Lau Francis C. M. 
Published: January 2006

AbstractGrid computing unifies distributed resources via its support for the creation and use of virtual organizations (VOs), where a VO represents a collection of distributed resources to be accessed through predefined resource sharing and coordination policies. We consider a special type of mobile processes, named Grid travelers, which can travel across boundaries of VOs for the detection of resource availability, to negotiate for the approval of access privileges and to conduct remote execution. A new security infrastructure named G‐PASS is proposed to guarantee the validity and integrity of the travelers and the critical security knowledge they collect while traveling, especially while crossing some VOs. G‐PASS borrows the idea of passport and custom, as well as the procedures for people's travel in real life, to provide role‐based delegation mapping and access control. We demonstrate the power and feasibility of G‐PASS with a simulated mobile agent environment and a distributed ray‐tracing application running on multiple VOs. Various security overheads coming from migration decisions and actual agent or process migration are reported. G‐PASS can be installed with Grid Security Infrastructure (GSI) as the base, which makes it compatible with the existing Grid middleware. Copyright © 2006 John Wiley & Sons, Ltd.
Human and pig SRY 5′ flanking sequences can direct reporter transgene expression to the genital ridge and to migrating neural crest cells
Authors: Boyer Alexandre , Pilon Nicolas , Raiwet Diana L. , Lussier Jacques G. , Silversides David W. 
Published: January 2006

AbstractMechanisms for sex determination vary greatly between animal groups, and include chromosome dosage and haploid–diploid mechanisms as seen in insects, temperature and environmental cues as seen in fish and reptiles, and gene‐based mechanisms as seen in birds and mammals. In eutherian mammals, sex determination is genetic, and SRY is the Y chromosome located gene representing the dominant testes determining factor. How SRY took over this function from ancestral mechanisms is not known, nor is it known what those ancestral mechanisms were. What is known is that SRY is haploid and thus poorly protected from mutations, and consequently is poorly conserved between mammalian species. To functionally compare SRY promoter sequences, we have generated transgenic mice with fluorescent reporter genes under the control of various lengths of human and pig SRY 5′ flanking sequences. Human SRY 5′ flanking sequences (5 Kb) supported reporter transgene expression within the genital ridge of male embryos at the time of sex determination and also supported expression within migrating truncal neural crest cells of both male and female embryos. The 4.6 Kb of pig SRY 5′ flanking sequences supported reporter transgene expression within the male genital ridge but not within the neural crest; however, 2.6 Kb and 1.6 Kb of pig SRY 5′ flanking sequences retained male genital ridge expression and now supported extensive expression within cells of the neural crest in embryos of both sexes. When 2 Kb of mouse SRY 5′ flanking sequences (−3 to −1 Kb) were placed in front of the 1.6 Kb of pig SRY 5′ flanking sequences and this transgene was introduced into mice, reporter transgene expression within the male genital ridge was retained but neural crest expression was lost. These observations suggest that SRY 5′ flanking sequences from at least two mammalian species contain elements that can support transgene expression within cells of the migrating neural crest and that additional SRY 5′ flanking sequences can extinguish this expression. Developmental Dynamics 235:623–632, 2006. © 2006 Wiley‐Liss, Inc.
Reactivity of 4,4‐Dichloro‐1,1‐diphenyl‐2‐azabutadiene Towards Alkoxides and Thiolates: Synthesis of Functionalised π‐Conjugated 2‐Azabutadienes and Unexpected 1,4‐Thiazine Formation
Authors: Jacquot‐Rousseau Sandrine , Schmitt Gérard , Khatyr Abderrahim , Knorr Michael , Kubicki Marek M. , Vigier Estelle , Blacque Olivier 
Published: January 2006

AbstractTreatment of 4,4‐dichloro‐1,1‐diphenyl‐2‐azabuta‐1,3‐diene [Cl2C=C(H)‐N=CPh2] (1) with excess sodium isopropylthiolate or sodium thiophenolate in DMF yielded the 2‐azabutadiene derivatives (RS)2C=C(H)–N=CPh2 (2) (2a R = iPr; 2b R = Ph). Nucleophilic attack of the sodium salt of ethyl thioglycolate on 1 afforded as the sole product the six‐membered heterocyclic compound ethyl 2‐ethoxycarbonylmethylthio‐5,5‐diphenyl‐5,6‐dihydro‐4H‐1,4‐thiazine‐6‐carboxylate (5). The reaction is initiated by substitution of the two vinyl‐bound chloro substituents to give {EtO(O=)CCH2S}2C=C(H)–N=CPh2 (2c) as intermediate. A mechanism that accounts for the subsequent cyclisation reaction is proposed. The 2‐azabutadiene derivative (PhO)2C=C(H)–N=CPh2 (7) was obtained by the reaction of 1 with sodium phenolate. The regioselectivity of the incoming nucleophile is roughly correlated with its hardness/softness in accord with Pearson’s HSAB principle. The molecular structures of 2a,b, 5 and 7 were determined by single‐crystal X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Modulation of Bis(triazine) Hydrogen‐Bonding Receptors
Authors: Mason Pamela V. , Champness Neil R. , Collinson Simon R. , Fisher Matthew G. , Goretzki Gudrun 
Published: January 2006

AbstractThe synthesis of bis(triazine) molecules capable of acting as synthetic receptors for barbiturate guest molecules is described. The binding properties are also reported illustrating the modulation of the binding properties of these species by the modification of the hydrogen‐bonding patterns of the receptor molecule, namely 1,3‐N,N′‐bis[4‐(dibenzylamino)‐6‐(butylamino)‐1,3,5‐triazin‐2‐yl]xylylenediamine (1). Thus 1,3‐O,O′‐bis[4‐(dibenzylamino)‐6‐(butylamino)‐1,3,5‐triazin‐2‐yl]benzenedimethanol (3) and 1,3‐O,O′‐bis[4‐(dibenzylamino)‐6‐(diethylamino)‐1,3,5‐triazin‐2‐yl]benzenedimethanol (5) have been prepared, and their binding constants compared to those observed for 1. In the case of compounds 3 and 5 the hydrogen‐bonding secondary amines at the apex of the receptor 1 are substituted by non‐hydrogen‐bonding ether links. The hydrogen‐bonding ability is further modified in the case of 5 by the removal of all hydrogen‐bond donors from the receptor site, replacing secondary amines by tertiary amines. NMR binding studies illustrate how these simple modifications of the hydrogen‐bonding patterns of these receptors influences the overall strength of binding demonstrating a simple mechanism for controlling host‐guest complex formation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
First Total Synthesis of Longimicin D
Authors: Tominaga Hiroaki , Maezaki Naoyoshi , Yanai Minori , Kojima Naoto , Urabe Daisuke , Ueki Risa , Tanaka Tetsuaki 
Published: January 2006

AbstractWe have accomplished the first total synthesis of longimicin D (1), which displays potent cytotoxicity against human pancreatic carcinoma cells. The bis‐THF core bearing congested stereocenters was constructed by our methodology for synthesis of poly‐THF cores, which consists of asymmetric alkynylation with the C4 unit and stereodivergent THF ring formation. Although we had planned to join the C9–C34 bis‐THF core segment 2 and the C1–C8 γ‐lactone segment 3, a model study revealed that the coupling was difficult. We resolved the problem by applying asymmetric alkynylation of bis‐THF aldehyde 24 with functionalized alkyne 19 respresenting the polymethylene chain from the C3 to C12 position. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Studies of DNA Damage Inhibition by Dietary Antioxidants Using Metallopolyion/DNA Sensors
Authors: Mugweru Amos , Rusling James 
Published: January 2006

AbstractVoltammetric sensors featuring thin‐films containing osmium and ruthenium metallopolymers were evaluated to monitor the influence of antioxidants on DNA damage reactions. In the first example, apigenin, chrysin, and ascorbic acid were shown to inhibit oxidation of DNA by hydroxyl radicals generated with Fenton's reagent. A second example involved films of DNA with myoglobin (Mb) as an enzyme mimic which was used to convert styrene to styrene oxide. Here, the Ru peak of the sensor served as a marker of DNA damage from adduct formation between nucleobases and styrene oxide. There was no influence of the antioxidants on the reaction of styrene oxide itself with DNA films, but significant damage protection was afforded by micromolar amounts of antioxidants when styrene oxide was generated by Mb in the sensor films. This suggests that protection ensued from action of the antioxidants at the enzyme conversion level, probably by reduction of the active ferryloxy intermediate of the protein. Results demonstrate the usefulness of the thin metallopolyion/DNA film sensors in investigations of DNA damage inhibition.
Bone morphogenetic protein 7 is widely overexpressed in primary breast cancer
Authors: Alarmo Emma‐Leena , Rauta Jenita , Kauraniemi Päivikki , Karhu Ritva , Kuukasjärvi Tuula , Kallioniemi Anne 
Published: January 2006

AbstractBone morphogenetic proteins (BMP) make up a family of extracellular signaling molecules that play a critical role in vertebrate development and both inhibit and stimulate growth in cancer cells. BMP7 was recently identified in our genomewide copy number and expression survey as being activated through amplification in breast cancer cell lines. In the present study, we further explored BMP7 gene copy number and expression changes in 22 breast cancer cell lines and 146 primary breast tumors. FISH analysis revealed that BMP7 copy number varied greatly from one cell line to another, with three cell lines showing extremely high‐level amplification. Among primary tumors, BMP7 copy number was increased in 16% of the cases. BMP7 mRNA expression was determined in the cell lines and in a subset of 44 tumor samples by RT‐PCR or quantitative real‐time RT‐PCR, respectively. Despite elevated mRNA levels in cancer cells, there was no significant association between copy number increase and mRNA expression, even though the highest expression was seen in cell lines and tumors with increased BMP7 copy number. Most interestingly, immunohistochemical analysis revealed BMP7 protein staining in all 11 breast cancer cell lines examined and strongly elevated BMP7 protein expression in 71.4% of the tumor samples as compared to normal mammary epithelium. Our results illustrate the frequent involvement of BMP7 alterations in breast cancer and especially highlight overexpression of the BMP7 protein in a very large fraction of primary breast tumors, thus suggesting a possible functional role for BMP7 in breast cancer development. © 2006 Wiley‐Liss, Inc.
Alpha‐tocopherol (vitamin E) induces rapid, nonsustained proliferation in cultured rat microglia
Authors: Flanary Barry E. , Streit Wolfgang J. 
Published: January 2006

AbstractMicroglial cells undergo cell division in vitro, as well as in vivo after brain injury. Mitotic activity of microglia suggests that they have limited life spans and rely on self‐renewal to replace senescent cells. In the current study we examined long‐term effects of antioxidants vitamin E and alpha‐lipoic acid on cultured rat microglia with respect to proliferative ability, telomere length, telomerase activity, and interleukin‐1β (IL‐1β) production. We report that vitamin E induces dramatic microglial proliferation, as measured by MTT assay and BrdU incorporation, surpassing that of the well‐known microglial mitogen granulocyte macrophage–colony stimulating factor, and therefore establishing vitamin E as the most potent, known mitogen for microglia in vitro. The high rate of microglial proliferation resulted in a concomitant decrease in telomere length and telomerase activity. Production of IL‐1β was significantly decreased in vitamin E–treated microglia in vitro. Our findings provide an impetus to investigate potential benefits of vitamin E supplementation on microglial renewal capacity in vivo during aging or after brain injury. © 2006 Wiley‐Liss, Inc.
Systematic Gaussian basis‐set limit using completeness‐optimized primitive sets. A case for magnetic properties
Authors: Manninen Pekka , Vaara Juha 
Published: January 2006

AbstractWe discuss the connection between the completeness of a basis set, measured by the completeness profiles introduced by Chong (Can J Chem 1995, 73, 79) at a certain exponent interval, and the possibility of reproducing molecular properties that arise either in the region close to the atomic nuclei or in the valence region. We present a scheme for generating completeness‐optimized Gaussian basis sets, in which a preselected range of exponents is covered to an arbitrary accuracy. This is done by requiring Gaussian functions, the exponents of which are selected without reference to the atomic structure, to span the range with completeness profile as close to unity as wanted with as few functions as possible. The initial exponent range can be chosen suitable for calculations of molecular energetics or other valence‐like properties. By extending the exponent range, properties requiring augmentation of the basis at a given angular momentum value and/or in a given distance range from the nucleus may be straightforwardly and systematically treated. In this scheme a universal, element‐independent exponent set is generated in an automated way. The relation of basis‐set completeness and performance in the calculation of magnetizability, nuclear magnetic shielding, and spin–spin coupling is tested with the completeness‐optimized primitive sets and literature basis sets. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 434–445, 2006
Development and progression of alopecia in the vitamin D receptor null mouse
Authors: Bikle Daniel D. , Elalieh Hashem , Chang Sandra , Xie Zhongjian , Sundberg John P. 
Published: January 2006

AbstractHumans with selected mutations in the vitamin D receptor (VDR) and mouse models lacking VDR develop alopecia. Mice null for the Vdr gene are born with a normal coat of hair, but fail to initiate normal hair follicle cycling. In this study, we examined the morphology of the hair follicle of the Vdr null mouse during days 13–22 when the hair follicle normally initiates and completes the first catagen. We then explored the possibility that the abnormality in hair follicle cycling was associated with abnormal expression of hairless (Hr), a putative transcriptional regulator known to regulate hair follicle cycling and recently shown to regulate VDR transcriptional activity. Our results demonstrate the progressive deterioration of the hair follicle through catagen. Comparable to VDR, Hr was found in the basal cells of the epidermis and ORS of the hair follicle. However, Hr was also found in the IRS and matrix of the follicle, regions with little or no VDR. Hr levels increased during catagen, reaching a peak by day 19. Levels of Hr were greater in the Vdr null mice compared to wildtype controls, results confirmed by quantitative RT‐PCR. We conclude that lack of VDR causes disruption of hair follicle structure during the first catagen resulting in failure of subsequent hair follicle cycling. These changes are associated with increased expression of Hr, suggesting a role for VDR in regulating Hr expression. Both Hr and VDR are required for normal hair follicle cycling. J. Cell. Physiol. 207: 340–353, 2006. © 2006 Wiley‐Liss, Inc.
SOCS‐2 interferes with myotube formation and potentiates osteoblast differentiation through upregulation of JunB in C2C12 cells
Authors: Ouyang Xinshou , Fujimoto Minoru , Nakagawa Reiko , Serada Satoshi , Tanaka Toshio , Nomura Shintaro , Kawase Ichiro , Kishimoto Tadamitsu , Naka Tetsuji 
Published: January 2006

AbstractSuppressor of cytokine signaling (SOCS)‐2 regulates normal postnatal growth and its deficiency in mice causes gigantism with increased bone length and proportional enlargement in skeletal muscles. Using C2C12 mesenchymal precursor cell line as a model, we investigated a possible role of SOCS‐2 in the differentiation process of mesenchymal precursors. Stable transfection of SOCS‐2 into C2C12 cells resulted in the acceleration of proliferation and survival, and inhibition of spontaneous myotube formation. In addition, SOCS‐2 potentiated bone morphogenic protein (BMP)‐induced transdifferentiation of C2C12 cells into osteoblast phenotypes. These effects of SOCS‐2 on C2C12 cells differed strikingly from that of SOCS‐1, another member of SOCS family, and its mechanisms were evaluated. SOCS‐2 did not alter BMP‐induced phosphorylation and nuclear accumulation of Smad1, nor the expression of inhibitory‐Smads mRNA. However, SOCS‐2 enhanced BMP‐induced transcriptional activation of the Smad‐responsive reporter gene, suggesting that the action of SOCS‐2 is exerted at the transcriptional level. Interestingly, SOCS‐2 overexpression in C2C12 cells increased the endogenous JunB protein, one of the key transcriptional factors in the control of BMP/Smad signaling responsiveness. In addition, the proteasome inhibitor enhanced JunB protein expression in C2C12 cells. Moreover, we found that SOCS‐2 reduced JunB ubiquitination in COS‐7 cells. Although SOCS‐2 is a modulator of growth hormone (GH) signaling, the upregulation of JunB by SOCS‐2 did not require GH signaling. Taken together, these results suggest that SOCS‐2 positively regulates endogenous JunB protein expression in C2C12 cells through inhibition of JunB destabilization by the ubiquitin–proteasome pathway, and thereby regulates the cell fate of mesenchymal precursors. J. Cell. Physiol. 207: 428–436, 2006. © 2006 Wiley‐Liss, Inc.