bluuebunny/crossref_metadata_2025_split huggingface dataset:
Latest Developments in the Catalytic Application of Nanoscaled Neutral Group 8–10 Metals
Authors: Zhu Yinghuai , Lee Cjin Nong , Kemp Richard A. , Hosmane Narayan S. , Maguire John A. 
Published: March 2008

AbstractIn the last few decades, the synthesis and catalytic application of nanoscaled particles prepared from Group 8–10 (formerly Group VIIIB) elements have been widely explored and have achieved promising results. The innovative use of these nanoparticle catalysts may provide new opportunities in the efficient combination of conventionally used homogenous and heterogeneous catalysts. Conventional homogeneous catalysts pose extraction and recycling difficulties when dealing with metal complexes and/or ligands, whereas heterogeneous catalysts generally require more pressing experimental conditions, such as high temperatures and high pressures, to be effective. Therefore, to solve these problems, the synthesis and use of nanoparticle catalysts as replacements for conventional catalytic systems is a breakthrough owing to their improved handling and environmental and economic aspects. This Focus Review primarily addresses the catalytic applications of neutral Group 8–10 nanoparticles with an average size of less than 10 nm, and also includes a discussion of commonly used synthetic methodology.
Hesperidin in orange juice reduces the absorption of celiprolol in rats
Authors: Uesawa Yoshihiro , Mohri Kiminori 
Published: March 2008

AbstractIt has been reported that the intestinal absorption of celiprolol, an antihypertensive drug, is inhibited when it is taken with orange juice; it has been suggested that element(s) in citrus juice are responsible for this. In the present study, the pharmacokinetic interaction between celiprolol and orange juice was characterized through in vivo experiments with rats. Celiprolol 5 mg/kg was injected into the rat duodenum together with 5 ml/kg of neutralized orange juice or the same concentration of hesperidin as in the orange juice. Plasma celiprolol concentrations were measured by liquid chromatography–electrospray ionization–mass spectrometry (LC‐ESI‐MS). Concomitant administration of orange juice or hesperidin with celiprolol significantly decreased the area under the plasma concentration–time curve (AUC) by 74% and 75%, respectively, compared with control. These findings suggest that hesperidin is responsible for the decreased absorption of celiprolol and that orange juice taken with celiprolol has an inhibiting effect on intestinal absorption of the drug. Copyright © 2008 John Wiley & Sons, Ltd.
Dental enamel as a dietary indicator in mammals
Authors: Lucas Peter , Constantino Paul , Wood Bernard , Lawn Brian 
Published: March 2008

AbstractThe considerable variation in shape, size, structure and properties of the enamel cap covering mammalian teeth is a topic of great evolutionary interest. No existing theories explain how such variations might be fit for the purpose of breaking food particles down. Borrowing from engineering materials science, we use principles of fracture and deformation of solids to provide a quantitative account of how mammalian enamel may be adapted to diet. Particular attention is paid to mammals that feed on ‘hard objects’ such as seeds and dry fruits, the outer casings of which appear to have evolved structures with properties similar to those of enamel. These foods are important in the diets of some primates, and have been heavily implicated as a key factor in the evolutionary history of the hominin clade. As a tissue with intrinsic weakness yet exceptional durability, enamel could be especially useful as a dietary indicator for extinct taxa. BioEssays 30:374–385, 2008. © 2008 Wiley Periodicals, Inc.
Genetic caste determination in termites: out of the shade but not from Mars
Authors: Crozier Ross H , Schlüns Helge 
Published: March 2008

AbstractSeveral ant species are known with genetic effects on caste determination but, for termites, the role of environment has been assumed to be omnipotent. Now Hayashi et al. report that commitment to the nymph and worker pathways in Reticulitermes speratus follows a simple model involving two alleles at a sex‐linked locus.1 The spread of this system of genetic caste determination seems best explained by selection at the colony level. This remarkable system may be widely applicable throughout termites, although it cannot be universal, and may provide a window into causal aspects of the molecular biology of caste determination. BioEssays 30:299–302, 2008. © 2008 Wiley Periodicals, Inc.
Alternative models for the evolution of eyespots and of serial homology on lepidopteran wings
Authors: Monteiro Antónia 
Published: March 2008

AbstractSerial homology is widespread in organismal design, but the origin and individuation of these repeated structures appears to differ with the different types of serial homologues, and remains an intriguing and exciting topic of research. Here I focus on the evolution of the serially repeated eyespots that decorate the margin of the wings of nymphalid butterflies. In this system, unresolved questions relate to the evolutionary steps that lead to the appearance of these serial homologues and how their separate identities evolved. I present and discuss two alternative hypotheses. The first proposes that eyespots first appeared as a row of undifferentiated repeated modules, one per wing compartment, that later become individuated. This individuation allowed eyespots to appear and disappear from specific wing compartments and also allowed eyespots to acquire different morphologies. The second hypothesis proposes that eyespots first appeared as individuated single units, or groups of units, that over evolutionary time were co‐opted into new compartments on the wing. I discuss the merits of each of these alternate hypotheses by finding analogies to other systems and propose research avenues for addressing these issues in the future. BioEssays 30:358–366, 2008. © 2008 Wiley Periodicals, Inc.
Modulation of VEGF signalling output by the Notch pathway
Authors: Siekmann Arndt F. , Covassin Laurence , Lawson Nathan D. 
Published: March 2008

AbstractThe formation of blood vessels within the vascular system entails a variety of cellular processes, including proliferation, migration and differentiation. In many cases, these diverse processes need to be finely coordinated among neighbouring endothelial cells in order to establish a functional vascular network. For instance, during angiogenic sprouting specialized endothelial tip cells follow guidance cues and migrate extensively into avascular tissues while trailing stalk cells must stay connected to the patent blood vessel. The vascular endothelial growth factor (VEGF) and Notch signalling pathways have emerged as the major players in governing these different cellular behaviours. In particular, recent work indicates an important role for Notch signalling in determining how an endothelial cell responds to VEGF. In this review, we provide an overview of these biochemically distinct pathways and discuss how they may interact during endothelial cell differentiation and angiogenesis. BioEssays 30:303–313, 2008. © 2008 Wiley Periodicals, Inc.
Method for tracking nanogel particles in vivo and in vitro
Authors: Seal Brandon L. , Lien Yeong‐Hau H. , Mazar Carla , Salkini Mohamad W. , Cai Tong , Hu Zhibing , Marquez Manuel , Garcia Antonio A. 
Published: March 2008

AbstractHydrogels made of N‐isopropylacrylamide (NIPA) can be synthesized in the form of highly monodispersed nanoparticles. After synthesis, NIPA hydrogel nanoparticles (nanogels) can be labeled by Alexa Fluor® 488 carboxylic acid, 2,3,5,6‐tetrafluorophenyl ester through amine‐terminated functional groups. This choice of dye is complementary to other biological labeling methods for in vivo studies. When the nanogel/dye nanoparticles are injected into rabbits, they can be imaged via tissue sectioning and confocal microscopy, while nanoparticle concentration can be determined by fluorescent microplate assays. Time‐course persistence of nanoparticles in the circulatory system can be readily tracked by direct assay of plasma and urine samples using 485 nm excitation and 538 emission wavelengths to keep background fluorescence to nearly the same level as that found using an empty well. Depending upon how the nanoparticles are injected, circulatory system concentrations can reach high concentrations and diminish to low levels or gradually increase and gradually decrease over time. Injection in the femoral artery results in a rapid spike in circulating nanogel/dye concentration, while injection into the renal artery results in a more gradual increase.
Characterization of RNA‐binding proteins possibly involved in modulating human AT1 receptor mRNA stability
Authors: Pende Aldo , Contini Lidia , Sallo Raffaella , Passalacqua Mario , Tanveer Rasheeda , Port J. David , Lotti Gaetano 
Published: March 2008

AbstractAngiotensin II exerts its cardiovascular effects mainly through the activation of AT1 receptors. These receptors can be regulated at a post‐transcriptional level, that is through the modulation of the mRNA stability. This regulation usually involves proteins which are able to bind the 3'UTR of the mRNA molecule. The experiments of the present paper were performed in order to characterize the RNA‐binding proteins interacting with the hAT1 receptor mRNA in human vascular smooth muscle cells. Immunoblot analysis allowed us to identify three different RNA‐binding proteins, AUF1, HuR, and hnRNP A1. UV cross‐linking and immunoprecipitation experiments demonstrated that AUF1 binds to the hAT1‐receptor mRNA radiolabeled probes specifically, but in different ways in relation to the clinically important A/C gene polymorphism. Gel shift experiments using purified recombinant proteins confirmed the specificity of interaction of these proteins with the hAT1‐receptor mRNA. In basal conditions the proteins were mainly located in the nuclei, but angiotensin II administration clearly induced their translocation to the cytosol. This observation was confirmed by transfection experiments using both GFP/AUF1 and GFP/HuR fusion proteins. Our findings allow identification of specific RNA‐binding proteins possibly involved in the control of the hAT1‐receptor mRNA stability and in the regulation of their expressions. Copyright © 2008 John Wiley & Sons, Ltd.
Multifunctional Fourfold Interpenetrating Diamondoid Network: Gas Separation and Fabrication of Palladium Nanoparticles
Authors: Cheon Young Eun , Suh Myunghyun Paik 
Published: March 2008

AbstractA fourfold interpenetrating diamondoid network, [{[Ni(cyclam)]2(mtb)}n]⋅8n H2O⋅4n DMF (1) (MTB=methanetetrabenzoate, DMF=dimethylformamide), has been assembled from [Ni(cyclam)][ClO4]2 (cyclam=1,4,8,11‐tetraazacyclotetradecane) and methanetetrabenzoic acid (H4MTB) in DMF/H2O (7:3, v/v) in the presence of triethylamine (TEA). Despite the high‐fold interpenetration, 1 generates 1D channels that are occupied by water and DMF guest molecules. Solid 1, after removal of guest molecules, exhibits selective gas adsorption behavior for H2, CO2, and O2 rather than N2 and CH4, suggesting possible applications in gas separation technologies. In addition, solid 1 can be applied in the fabrication of small Pd (2.0±0.6 nm) nanoparticles without any extra reducing or capping agent because a NiII macrocyclic species incorporated in 1 reduces PdII ions to Pd0 on immersion of 1 in the solution of Pd(NO3)2⋅2 H2O in MeCN at room temperature.
Gold‐Nanorod‐Based Sensing of Sequence Specific HIV‐1 Virus DNA by Using Hyper‐Rayleigh Scattering Spectroscopy
Authors: Darbha Gopala Krishna , Rai Uma Shanker , Singh Anant Kumar , Ray Paresh Chandra 
Published: March 2008

AbstractInfectious diseases caused by the human immunodeficiency virus (HIV) remain the leading killers of human beings worldwide, and function to destabilize societies in Africa, Asia, and the Middle East. Driven by the need to detect the presence of HIV viral sequence, here we demonstrate that the second‐order nonlinear optical (NLO) properties of gold nanorods can be used for screening HIV‐1 viral DNA sequence without any modification, with good sensitivity (100 pico‐molar) and selectivity (single base‐pair mismatch). The hyper‐Rayleigh scattering (HRS) intensity increases 45 times when a label‐free 145‐mer, ss‐gag gene DNA, was hybridized with 100 pM target DNA. The mechanism of HRS intensity change has been discussed with experimental evidence for higher multipolar contribution to the NLO response of gold nanorods.
Automated Solid‐Phase Synthesis of Protected Oligosaccharides Containing β‐Mannosidic Linkages
Authors: Codée Jeroen D. C. , Kröck Lenz , Castagner Bastien , Seeberger Peter H. 
Published: March 2008

AbstractFor automated oligosaccharide synthesis to impact glycobiology, synthetic access to most carbohydrates has to become efficient and routine. Methods to install “difficult” glycosidic linkages have to be established and incorporated into the overall synthetic concept. Described here is the first automated solid‐phase synthesis of oligosaccharides containing the challenging β‐mannosidic linkage. Carboxybenzyl mannoside building blocks proved effective β‐mannosylation agents and resulted in excellent conversion and good to moderate selectivities. [(Triisopropylsilyl)oxy]‐methyl ether (Tom), served as an orthogonal, minimally intrusive, and readily cleavable protecting group for the elongation of the C3 position of mannose. The desired oligosaccharide products were readily separated from by‐products containing unwanted stereoisomers using reverse‐phase HPLC. The methods described here expand the scope of carbohydrates currently accessible by automation as many oligosaccharides of biological interest contain β‐mannosidic linkages.
A Highly Selective Colorimetric Aqueous Sensor for Mercury
Authors: Shunmugam Raja , Gabriel Gregory J. , Smith Cartney E. , Aamer Khaled A. , Tew Gregory N. 
Published: March 2008

AbstractA new colorimetric mercury sensor is reported based on binding to terpyridine derivatives. It is able to selectively detect HgII ions over a number of environmentally relevant ions including CaII, PbII, ZnII, CdII, NiII, CuII, and others. The response time upon exposure to HgII is instantaneous. By the “naked eye,” the detection limit of HgII is 2 ppm (25 μM) in solution. With a spectrometer, this detection limit is increased down to 2 ppb (25 nM), which is the current EPA standard for drinking water. The significant problem of mercury poisoning requires new methods of detection that are sensitive and selective. Here we report a new simple system that takes advantage of the unique optical properties generated by terpyiridine–Hg complexes.
Exploiting Threefold Symmetry in Asymmetric Catalysis: The Case of Tris(oxazolinyl)ethanes (“Trisox”)
Authors: Gade Lutz H. , Bellemin‐Laponnaz Stéphane 
Published: March 2008

AbstractRotational molecular symmetry, modularity and other aspects of ligand design have played a role in the development of a new class of stereodirecting ligands. The use of highly symmetrical, stereodirecting ligands may reduce the number of transition states and diastereomeric reaction intermediates and, in favourable cases, this degeneration of alternative reaction pathways may lead to high stereoselectivity in catalytic reactions and greatly simplifies the analysis of such transformations. In this concept article, we describe the way in which these considerations have played a role in the development of a new class of stereodirecting ligands. Tris(oxazolinyl)ethanes (“trisox”) have proved to be versatile ligand systems for the development of enantioselective catalysts of the d‐ and f‐block metals employed in a wide range of catalytic conversions. These include Lewis acid catalysed transesterifications, CC and CN coupling reactions, the catalytic polymerisation of α‐olefins as well as Pd‐catalysed allylic alkylations. An overview of the current state of this field is given and the potential for further development will be highlighted.
Stepwise Oxidation of the Stannole Dianion
Authors: Haga Ryuta , Saito Masaichi , Yoshioka Michikazu 
Published: March 2008

AbstractTin oxidation of stannole dianion 1 with 1.3 equivalents of oxygen gave terstannole‐1,3‐dianion 3. The non‐aromatic nature of 3 was confirmed by X‐ray crystallographic analysis. Treatment of 1 with 1,2‐dibromoethane (3 equiv) gave poly(1,1‐stannole) 4, the formation of which was proven by reduction of 4 with lithium to revert to the starting dianion 1. Reaction of 1 with 1,2‐dibromoethane (3 equiv) in the presence of phenyllithium gave phenyl‐capped ter(1,1‐stannole) 7. The electronic absorption spectra of newly obtained stannoles were also measured.
Heterometallic [Mn5‐Ln4] Single‐Molecule Magnets with High Anisotropy Barriers
Authors: Mereacre Valeriu , Ako Ayuk M. , Clérac Rodolphe , Wernsdorfer Wolfgang , Hewitt Ian J. , Anson Christopher E. , Powell Annie K. 
Published: March 2008

AbstractThe reaction of [Mn6O2(Piv)10(4‐Me‐py)2.5(PivH)1.5] (1) (py: pyridine, Piv: pivilate) with N‐methyldiethanolamine (mdeaH2) and Ln(NO3)3⋅6 H2O in MeCN leads to a series of nonanuclear compounds [Mn5Ln4(O)6(mdea)2(mdeaH)2(Piv)6(NO3)4(H2O)2]⋅2 MeCN (Ln=TbIII (2), DyIII (3), HoIII (4), YIII (5)). Single‐crystal X‐ray diffraction shows that compounds 2–5 are isostructural, with the central core composed of two distorted {MnIVMnIIILn2O4} cubanes sharing a MnIV vertex, representing a new heterometallic 3d–4f motif for this class of ligand. The four new compounds display single‐molecule magnet (SMM) behaviour, which is modulated by the lanthanide ion used. Moreover, the values found for Δeff and τo for 3 of 38.6 K and 3.0×10−9 s respectively reveal that the complex 3 exhibits the highest energy barrier recorded so far for 3d–4f SMMs. The slow relaxation of the magnetisation for 3 was confirmed by μ‐SQUID measurements on an oriented single crystal and the observation of M versus H hysteresis loops below 1.9 K.
Indicators of survival duration in ovarian cancer and implications for aggressiveness of care
Authors: von Gruenigen Vivian , Daly Barbara , Gibbons Heidi , Hutchins Jessica , Green Andrew 
Published: March 2008

AbstractBACKGROUND.Ovarian cancer patients frequently receive chemotherapy near the end of life. The purpose of the current study was to develop indicators that characterize those ovarian cancer patients who have a short life span.METHODS.The medical charts of deceased epithelial ovarian cancer patients were retrospectively reviewed from 2000 through 2006. All patients received primary debulking surgery and adjuvant chemotherapy. Aggressiveness of cancer care within the last month of life was measured by chemotherapy regimens, emergency room visits, and hospitalizations. Significant clinical events (SCE) were defined as ascites, bowel obstruction, and pleural effusion. Survival quartiles were compared using chi‐square and Student t test statistics. Multiple regression analysis was performed using survival duration as a dependent variable.RESULTS.In all, 113 patients with epithelial ovarian cancer were reviewed. Patients had increased hospitalizations (P < .001) and SCE (P < .001) as they approached the end of life. There was no difference in the pattern of hospitalizations and SCE between the top and bottom survival quartiles. Patients with a shorter survival time had a trend toward increased chemotherapy during their last 3 months of life (P = .057) and had increased overall aggressiveness of care (P = .013). In patients with a disease remission, the length of initial remission time was found to be significant in predicting survival (P < .01). Time to second disease recurrence was also significant in predicting survival time (P < 0.01).CONCLUSIONS.Patients who received aggressive care did not have improvement in survival. Short disease remissions and increasing hospitalizations with SCE should be indicators of the appropriateness of reducing cure‐oriented therapies and increasing palliative interventions. Cancer 2008. ©2008 American Cancer Society.
Survival and predictors of outcome in patients with acute leukemia admitted to the intensive care unit
Authors: Thakkar Snehal G. , Fu Alex Z. , Sweetenham John W. , Mciver Zachariah A. , Mohan Sanjay R. , Ramsingh Giridharan , Advani Anjali S. , Sobecks Ronald , Rybicki Lisa , Kalaycio Matt , Sekeres Mikkael A. 
Published: March 2008

AbstractBACKGROUND.Predictors of outcome and rates of successful discharge have not been defined for patients with acute leukemia admitted to intensive care units (ICUs) in the US.METHODS.This is a retrospective analysis of 90 patients with acute leukemia (no history of bone marrow transplant) admitted to an ICU from 2001–2004. The primary endpoints were improvement and subsequent discharge from the ICU, discharge from the hospital, and 2‐month survival after hospital discharge. Secondary endpoints were 6‐ and 12‐month survival. Univariate and multivariate logistic regression analyses were performed to identify factors predicting outcome.RESULTS.The median age of patients was 54 years and 48 (53%) were male. The most common reason for ICU transfer for all patients was respiratory compromise. The majority of all patients (68%) were eventually placed on ventilator support and approximately half required pressors. During the ICU course, 29 patients (32%) improved and subsequently resumed aggressive leukemia management, and 24 patients (27%) survived to be discharged from the hospital. The 2‐, 6‐, and 12‐month overall survival was 24 (27%), 16 (18%), and 14 (16%), respectively. Higher APACHE II score, use of pressors, undergoing bone marrow transplantation preparative regimen, and adverse cytogenetics predicted worse outcome. Newly diagnosed leukemia, type of leukemia, or age did not.CONCLUSIONS.One of 4 patients with acute leukemia survived an ICU admission to be discharged from the hospital and were alive 2 months later. A diagnosis of acute leukemia should not disqualify patients from an ICU admission. Cancer 2008. © 2008 American Cancer Society.
Lobular neoplasia on core needle biopsy does not require excision
Authors: Nagi Chandandeep S. , O'Donnell James E. , Tismenetsky Mikhail , Bleiweiss Ira J. , Jaffer Shabnam M. 
Published: March 2008

AbstractBACKGROUND.Lobular neoplasia (LN), encompassing atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), is often an incidental finding on core needle biopsies (CNBs) performed in instances of radiologic densities and/or calcifications. Because LN is generally considered a risk factor for breast carcinoma, the utility of subsequent excision is controversial.METHODS.The authors' database yielded 98 cases of LCIS and/or ALH. Cases containing LN accompanied by a second lesion mandating excision (eg, radial scar, atypical ductal hyperplasia [ADH]) and those failing to meet strict diagnostic criteria for LN (eg, atypical cells, mitoses, single‐cell necrosis) were excluded. Radiographic calcifications were correlated with their histologic counterparts in terms of size, number, and pattern.RESULTS.Ninety‐one biopsies were performed for calcifications and 7 were performed for mass lesions. The ages of the patients ranged from 35 to 82 years. Fifty‐three patients were followed radiologically without excision, 42 of whom had available clinicoradiologic information. The 45 patients who underwent excision were without disease at follow‐up periods ranging from 1 to 8 years. Of these 45 patients, 42 (93%) had biopsy results demonstrating only LN. The remaining 3 patients had biopsies with the following findings: ADH in 1 biopsy, residual LCIS and a separate minute focus of infiltrating lobular carcinoma (clearly an incidental finding) in the second biopsy, and ductal carcinoma in situ admixed with LCIS in the third biopsy (a retrospective examination performed by 2 blinded breast pathologists revealed foci of atypical cells and mitoses).CONCLUSIONS.Excision of LN is unnecessary provided that: 1) careful radiographic‐pathologic correlation is performed; and 2) strict histologic criteria are adhered to when making the diagnosis. Close radiologic and clinical follow‐up is adequate. Cancer 2008. © 2008 American Cancer Society.