bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating cell death in G2M using bivariate BrdUrd/DNA flow cytometry
Authors: White R. Allen , Asmuth David M. , Lu Ying , Wang Nan , Li Xiao‐Dong , Reece Lisa , Pollard Richard B. , Nokta Mostafa , Leary James F. , Terry Nicholas H. A. 
Published: May 2005

AbstractBackgroundIn an accompanying paper (Asmuth et al.) it was found necessary to include cell death explicitly to estimate parameters of cell proliferation. The use of bivariate flow cytometry to estimate the phase durations and the doubling times of cells labeled with thymidine analogues is well established. However, these methods of analysis do not consider the possibility of cell death. This report demonstrates that estimating cell death in G2/M is possible.MethodsMathematical models for the experimental quantities, the fraction of labeled undivided cells, the fraction of labeled divided cells, and the relative movement were developed. These models include the possibility that, of the cells with G2/M DNA content, only a certain fraction will divide, with the remainder dying after some time TR. Simulation studies were conducted to test the possibility of using simple methods to estimate phase durations and cell death rates.ResultsCell death alters the estimates of phase transit times in a rather complex manner that depends on the lifetime of the doomed cells. However, it is still possible to obtain estimates of the phase durations of cells in S and G2/M and the death rates of cells in G2/M.ConclusionsThe methods presented herein provide a new way to characterize cell populations that includes cell death rates and common measurements of cell proliferation. © 2005 Wiley‐Liss, Inc.
Novel fluorescence assay using calcein‐AM for the determination of human erythrocyte viability and aging
Authors: Bratosin Daniela , Mitrofan Laura , Palii Carmen , Estaquier Jérôme , Montreuil Jean 
Published: May 2005

AbstractBackgroundA highly sensitive, fast, and simple flow cytometric assay to assess human red blood cell (RBCs) viability and aging is reported.MethodsThe assay described in this report is based on the use of acetoxymethyl ester of calcein (calcein‐AM), a fluorescein derivative and nonfluorescent vital dye that passively crosses the cell membrane of viable cells and is converted by cytosolic esterases into green fluorescent calcein, which is retained by cells with intact membranes and inactive multidrug resistance protein. The loss of calcein can be easily determined by flow cytometry, and the cytosolic localization of esterases was demonstrated by spectrofluorometric analyses.ResultsWe found that RBCs incubated with Ca2+, which induces a rapid and modulated self‐death that shares several features with apoptosis (Bratosin et al., Cell Death Differ 2001;8:1143–1156), externalized phosphatidylserine and lost calcein staining and cytosolic adenosine triphosphate content. Double labeling using phycoerythrin‐labeled annexin‐V and calcein‐AM showed that the decrease of esterase activity is an early event that precedes the externalization of phosphatidylserine residues. In addition, this assay allowed us to distinguish young and aged RBCs isolated by ultracentrifugation in a self‐forming Percoll gradient and can be considered as a reliable marker of RBC aging.ConclusionsCalcein‐AM assay may represent a wide application for assessing RBC viability, particularly in blood banks. © 2005 Wiley‐Liss, Inc.
Segmentation of complex cell clusters in microscopic images: Application to bone marrow samples
Authors: Nilsson Björn , Heyden Anders 
Published: May 2005

AbstractBackgroundMorphologic examination of bone marrow and peripheral blood samples continues to be the cornerstone in diagnostic hematology. In recent years, interest in automatic leukocyte classification using image analysis has increased rapidly. Such systems collect a series of images in which each cell must be segmented accurately to be classified correctly. Although segmentation algorithms have been developed for sparse cells in peripheral blood, the problem of segmenting the complex cell clusters characterizing bone marrow images is harder and has not been addressed previously.MethodsWe present a novel algorithm for segmenting clusters of any number of densely packed cells. The algorithm first oversegments the image into cell subparts. These parts are then assembled into complete cells by solving a combinatorial optimization problem in an efficient way.ResultsOur experimental results show that the algorithm succeeds in correctly segmenting densely clustered leukocytes in bone marrow images.ConclusionsThe presented algorithm enables image analysis–based analysis of bone marrow samples for the first time and may also be adopted for other digital cytometric applications where separation of complex cell clusters is required. © 2005 Wiley‐Liss, Inc.
C–H vs. N–H Bond Activation in Aminophosphane Ligands: Reaction of [Cp*Ru(MeCN)2(PR12NHR2)]+ (R1 = Ph, iPr; R2 = Ph, C6F5) with Alkynes
Authors: Jiménez‐Tenorio Manuel , Puerta M. Carmen , Valerga Pedro 
Published: May 2005

AbstractThe reaction of the complexes [Cp*Ru(MeCN)2(PR12NHR2)]+ (R1 = R2 = Ph 1; R1 = iPr, R2 = C6F5 2; R1 = iPr, R2 = Ph 3) with 1‐alkynes HC≡CR (R = H, nBu, SiMe3) or diynes HC≡CCH2XCH2C≡CH (X = O, CH2, CH2CH2) yields different products depending on the nature of the aminophosphane ligand. In some cases, alkyne coupling involving migration of the phosphane and N–H activation occurs, yielding amidobutadiene complexes of the type [Cp*Ru{η4‐C4H3(R)2PR12NR2‐κ1N}]+ or [Cp*Ru{η4‐C4H3(CH2XCH2)PR12NR2‐κ1N}]+. The complexes [Cp*Ru{η4‐C4H3(CH2OCH2)PPh2NPh‐κ1N}][PF6] (1a) and [Cp*Ru{η4‐C4H3(CH2OCH2)PiPr2NC6F5‐κ1N}][PF6] (2a) have been structurally characterized by X‐ray crystallography. In other cases, for example the reaction of 3 with HC≡CR (R = nBu, SiMe3), C–H bond activation at the ortho‐position of the phenyl ring of the phenylamino moiety and coupling to the alkyne fragment takes place. This results in the formation of the novel π‐alkene complexes [Cp*Ru(MeCN){η2‐RCH=CH(C6H4)NHPiPr2‐κ1P}]+ (R = nBu 4, SiMe3 5), formally derived from the insertion of the alkyne into the ortho‐C–H bond of the phenyl ring. The derivative [Cp*Ru(MeCN){η2‐nBuCH=CH(C6H4)NHPiPr2‐κ1P}][BPh4] has been structurally characterized by X‐ray crystallography. These compounds are related to the also structurally characterized olefin complex [Cp*Ru(MeCN)(η2‐MeOOCCH=CH2)(PPh2NHPh)][PF6] (6), generated by reaction of 1 with methyl acrylate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and X‐ray Molecular Structure of (PNP)2[MoIV(C6H4S2‐1,2)3] Completing the Structural Characterization of the Series [Mo(C6H4S2‐1,2)3]n– (n = 0, 1, 2)
Authors: Schulze Isfort Christian , Pape Tania , Hahn F. Ekkehardt 
Published: May 2005

AbstractThe tris(benzene‐1,2‐dithiolato) complex (Li)2[MoIV(C6H4S2‐1,2)3] {(Li)2[MoIV(bdt)3]} (bdt2– = C6H4S2‐1,2 dianion) was synthesized from [MoCl4(CH3CN)2], (H2bdt), and nBuLi in THF. Complex (Li)2[MoIV(bdt)3] undergoes aerial oxidation to give Li[MoV(bdt)3]. Both complexes were crystallized from methanol as the salts (PNP)2[MoIV(bdt)3] and (PNP)[MoV(bdt)3] {PNP+ = bis(triphenylphosphoranylidene)ammonium cation}, and their molecular structures were determined by X‐ray diffraction. The molybdenum(IV) complex [MoIV(bdt)3]2– assumes a distorted trigonal prismatic coordination geometry (average twist angle= 24.8°) while the coordination geometry of [MoV(bdt)3]– is best described as distorted octahedral (average twist angle= 34.1°). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Binuclear Copper(II) Complex Containing the Pyrazine‐2,5‐dicarboxylate Ligand: Study of the Magnetic Exchange through the Pyrazine Bridge
Authors: Beobide Garikoitz , Castillo Oscar , García‐Couceiro Urko , García‐Terán Juan P. , Luque Antonio , Martínez‐Ripoll Martín , Román Pascual 
Published: May 2005

AbstractThe compound [Cu2(μ‐pzdc)(phen)4](NO3)2·10H2O (1; pzdc = pyrazine‐2,5‐dicarboxylato; phen = 1,10‐phenanthroline) has been structurally and magnetically characterised. Theoretical calculations have allowed us to establish a plausible magneto‐structural correlation for pyrazine‐bridged complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Diastereoselective Lewis Acid Mediated Reductions of α‐Alkyl‐β‐Functionalized Carbonyl Compounds
Authors: Bartoli Giuseppe , Bartolacci Massimo , Giuliani Arianna , Marcantoni Enrico , Massaccesi Massimo 
Published: May 2005

AbstractA high stereochemical induction has often been observed in the reduction of ketones with stereogenic centres close to the carbonyl function. The level of stereoselectivity is particularly high when “hard” donor groups such as nitrogen or oxygen atoms are present in the molecule. These results have been commonly explained in terms of a chelate‐controlled process. However, this interpretation has recently been challenged, and in many cases an open‐chain mechanism can better account for the observed results. Thus, Lewis‐acid‐mediated chelation and nonchelation control is one of the most fundamental and practical concepts in transferring a nucleophile moiety to carbonyl compounds. In order to clarify the role of a hard Lewis acid in controlling the stereochemical outcome of a given reaction, the Lewis acid mediated reduction of a series of α‐alkyl‐β‐functionalized carbonyl compounds with metallic hydrides in various solvents was recently investigated. In particular, the results derived from the reductions in the presence of dry CeCl3were compared to those obtained under the same experimental conditions but in the presence of TiCl4, whose ability to form chelation complexes is well established. These investigations show a stereochemical outcome that is fully consistent with a chelation‐controlled pathway in the case of titanium, and an open‐chain‐controlled pathway in the case of CeCl3. The strongly chelating TiCl4led to thesynisomer in high diastereomeric excess in noncoordinating solvents at –78 °C with borane–Lewis base complex reducing agents, while nonchelating CeCl3produced a high excess of theantiisomer in coordinating solvents at the same temperature with metal borohydrides as reducing agent. Therefore, our method based on the choice of CeCl3or TiCl4as a Lewis acid under the reported conditions represents a significant contribution to the development of new stereoselective reductions of α‐alkyl‐β‐functionalized ketones. These procedures are one of the best known ways to obtain an alcoholic moiety. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Iridium(I)‐Catalysed Tandem Hydrosilylation‐Protodesilylation of Imines
Authors: Field Leslie D. , Messerle Barbara A. , Rumble Sarah L. 
Published: May 2005

AbstractIn the presence of alkylsilanes, the cationic IrI complex [{Ir[bis(pyrazol‐1‐yl)methane](CO)2}BPh4] (1) catalyses the reduction of a range of imines, including N‐alkyl and N‐aryl imines, and both aldimines and ketimines. Excellent conversions directly to the product amines are achieved rapidly at room temperature in methanol solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Proton‐Conducting Polymer Electrolyte Membranes Based on Fluoropolymers Incorporating Perfluorovinyl Ether Sulfonic Acids and Fluoroalkenes: Synthesis and Characterization
Authors: Souzy R. , Ameduri B. , Boutevin B. , Capron P. , Marsacq D. , Gebel G. 
Published: May 2005

AbstractThis paper presents the synthesis of new polymer electrolyte membranes based on fluoropolymers incorporating aromatic perfluorovinyl ether sulfonic acids. A novel synthetic route describing the preparation of perfluorovinyl ether monomer containing sulfonic functionalities, 4‐[(α,β,β‐trifluorovinyl)‐oxy]benzene sulfonic acid (TFVOBSA), is reported. The radical (co) and terpolymerisation of 4‐[(α,β,β‐trifluorovinyl)oxy]benzene sulfonyl chloride (TFVOBSC) with 1,1‐difluoroethylene (or vinylidene fluoride, VDF), hexafluoropropene (HFP), and perfluoromethyl vinyl ether (PMVE) is described. The terpolymers of TFVOBSC with VDF and HFP, or VDF and PMVE, were hydrolysed and also led to new fluorinated terpolymers bearing sulfonic acid aromatic side‐groups. The terpolymers were characterized by 1H and 19F NMR spectroscopies, SEC, DSC, and TGA. Membranes incorporating these functional fluoropolymers were prepared and the electrochemical properties (IEC, proton conductivity, swelling rates) were studied and discussed.
Complex chromosome aberrations persist in individuals many years after occupational exposure to densely ionizing radiation: An mFISH study
Authors: Hande M. Prakash , Azizova Tamara V. , Burak Ludmilla E. , Khokhryakov Valentin F. , Geard Charles R. , Brenner David J. 
Published: May 2005

AbstractLong‐lived, sensitive, and specific biomarkers of particular mutagenic agents are much sought after and potentially have broad applications in the fields of cancer biology, epidemiology, and prevention. Many clastogens induce a spectrum of chromosome aberrations, and some of them can be exploited as biomarkers of exposure. Densely ionizing radiation, for example, alpha particle radiation (from radon or plutonium) and neutron radiation, preferentially induces complex chromosome aberrations, which can be detected by the 24‐color multifluor fluorescence in situ hybridization (mFISH) technique. We report the detection and quantification of stable complex chromosome aberrations in lymphocytes of healthy former nuclear‐weapons workers, who were exposed many years ago to plutonium, gamma rays, or both, at the Mayak weapons complex in Russia. We analyzed peripheral‐blood lymphocytes from these individuals for the presence of persistent complex chromosome aberrations. A significantly elevated frequency of complex chromosome translocations was detected in the highly exposed plutonium workers but not in the group exposed only to high doses of gamma radiation. No such differences were found for simple chromosomal aberrations. The results suggest that stable complex chromosomal translocations represent a long‐lived, quantitative, low‐background biomarker of densely ionizing radiation for human populations exposed many years ago. © 2005 Wiley‐Liss, Inc.
Early evening low alcohol intake also worsens sleepiness‐related driving impairment
Authors: Barrett Pauline R. , Horne James A. , Reyner Louise A. 
Published: May 2005

AbstractFollowing night‐time sleep restriction, afternoon driving performance during the bi‐circadian surge in afternoon sleepiness is markedly worsened by blood alcohol concentrations (BACs) well under most national driving limits. This study assessed how driving with this same sleep restriction and BACs (av 40 mg and 28 mg alcohol/100 ml blood at the beginning and end of drive, respectively) respond during the evening circadian rise in alertness. In a 2 × 2 (alcohol versus control drink [double blind] × normal night sleep versus sleep restricted), repeated‐measures design, eight healthy young men drove for 2 h from 18:00 h, in a real‐car simulator, on a monotonous, simulated highway. Driving impairment (lane drifting), subjective sleepiness and EEG measures of sleepiness were recorded. While sleep restriction alone produced significant impairments to evening driving and subjective sleepiness, alcohol alone did not. However, alcohol combined with sleep restriction significantly worsened all indices, although, this was less than that found for afternoon driving with identical interventions. Whereas low BACs may not affect driving in normally alert drivers in the early evening, the addition of moderate sleep restriction still produces a dangerous combination. Probably, there is no ‘safe’ level of alcohol intake for otherwise sleepy drivers, at any time of the day. Copyright © 2005 John Wiley & Sons, Ltd.
Involvement of the NMDA receptor, NO‐cyclic GMP and nuclear factor K‐β in an animal model of repeated trauma
Authors: Harvey Brian H. , Bothma Tanya , Nel Ané , Wegener Gregers , Stein Dan J. 
Published: May 2005

AbstractPost‐traumatic stress disorder (PTSD) may be associated with shrinkage of the hippocampus, with glutamate release causally related to these events. Recent animal studies strongly implicate activation of the nitric oxide (NO)‐cascade in anxiety and stress. Using an animal model of repeated trauma, the effect of stress was investigated on the hippocampal NO‐cGMP signalling pathway, specifically the release of nitrogen oxides (NOx) and its modulation by NMDA receptor‐, NO‐, cGMP‐ and nuclear factor K‐β (NFK‐β)‐selective drugs. Immediately after stress, rats received the glutamate NMDA receptor antagonist, memantine (MEM; 5 mg/kg i.p./d), the NO synthase inhibitor, 7‐nitroindazole sodium salt (7‐NINA; 20 mg/kg i.p./d), the cGMP‐specific PDE inhibitor, sildenafil (SIL; 10 mg/kg i.p./d) or the NFκ‐β antagonist, pyrollidine dithiocarbamate (PDTC; 70 mg/kg i.p./d), for 7 days. Stress significantly increased hippocampal NOx on day 7 post‐stress, which was blocked by either 7‐NINA or PDTC, while MEM was without effect. SIL, however, significantly augmented stress‐induced NOx accumulation. Increased cGMP therefore acts as a protagonist in driving stress‐related events, while both nNOS (neuronal NOS) and iNOS (inducible/immunological NOS) may represent a therapeutic target in preventing the effects of severe stress. The value of NMDA receptor antagonism, however, appears limited in this model. Copyright © 2005 John Wiley & Sons, Ltd.
HA/TCP compounding of a porous CaP biomaterial improves bone formation and scaffold degradation—A long‐term histological study
Authors: Schopper Christian , Ziya‐Ghazvini Farzad , Goriwoda Walter , Moser Doris , Wanschitz Felix , Spassova Else , Lagogiannis Georgios , Auterith Alexandra , Ewers Rolf 
Published: May 2005

AbstractIn the present study, two biphasic calcium phosphate biomaterials (BCP) with HA/TCP ratios of 50/50 and 30/70 were obtained from a pure HA biomaterial. The biomaterials which showed the same three‐dimensional geometry were implanted into corticocancellous costal defects of sheep. In the specimens of all three biomaterials, abundant bone formation, mineral dissolution from the biomaterial scaffolds, and active cellular resorption of the scaffolds was present after 6 and 12 months. Backscattered electron microscopy showed bone invasion into the pores of the scaffolds and micromechanical interlocking at the bone/biomaterial interface without intervening soft tissue. The pattern of bone formation and scaffold resorption was different for cortical and cancellous bone. No time‐based effect, however, was observed. Overall, the BCP biomaterials had formed significantly more bone than the HA biomaterial. Also, scaffold resorption, which was followed by a replacement with newly formed bone, was significantly higher in the BCP biomaterials. Although no significant differences were observed between both BCP biomaterials, the present study had confirmed the assumption that HA/TCP compounding was suitable to improve bone formation and scaffold resorption in the investigated biomaterials and at the same time maintain the osteoconductive properties of the scaffolds. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Nowhere‐zero 3‐flows in products of graphs
Authors: Shu Jinlong , Zhang Cun‐Quan 
Published: May 2005

AbstractA graph G is an odd‐circuit tree if every block of G is an odd length circuit. It is proved in this paper that the product of every pair of graphs G and H admits a nowhere‐zero 3‐flow unless G is an odd‐circuit tree and H has a bridge. This theorem is a partial result to the Tutte's 3‐flow conjecture and generalizes a result by Imrich and Skrekovski [7] that the product of two bipartite graphs admits a nowhere‐zero 3‐flow. A byproduct of this theorem is that every bridgeless Cayley graph G = Cay(Γ,S) on an abelian group Γ with a minimal generating set S admits a nowhere‐zero 3‐flow except for odd prisms. © 2005 Wiley Periodicals, Inc. J Graph Theory
Early Detection of Acute Renal Failure by Serum Cystatin C: a New Opportunity for a Hepatologist
Authors: Mazur Marek J. , Heilman Raymond L. 
Published: May 2005

Abstract

Acute renal failure (ARF) is associated with high mortality. Presently, no specific therapy for ARF exists. Therefore, early detection of ARF is critical to prevent its progression. However, serum creatinine, the standard marker to detect ARF, demonstrates major limitations. We prospectively evaluated whether serum cystatin C detected ARF earlier than serum creatinine. In 85 patients at high risk to develop ARF, serum creatinine and cystatin C were determined daily. ARF was defined according to the Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and ESRD (RIFLE) classification when creatinine increased by >/= 50% (R-criteria), by >/= 100% (I-criteria), or by >/= 200% (F-criteria). In analogy, ARF was detected when cystatin C increased by >/= 50%, by >/= 100%, or by >/= 200%. Forty-four patients developed ARF and 41 served as controls. In ARF by R-, I-, and F-criteria, the increase of cystatin C significantly preceded that of creatinine. Specifically, serum cystatin C increased already by >/= 50% 1.5 +/− 0.6 days earlier compared to creatinine. Serum cystatin C demonstrated a high diagnostic value to detect ARF as indicated by area under the curve of the ROC analysis of 0.82 and 0.97 on the two days before the R-criteria was fulfilled by creatinine. Cystatin C detected ARF according to the R-criteria with a sensitivity of 55% and 82% on these days, respectively. Cystatin C also performed excellently, detecting ARF defined by the I- and F-criteria two days prior to creatinine, and moderately well predicting renal replacement therapy in the further course of ARF. Additionally, low T(3)- or T(3)/T(4) syndrome, glucocorticoid deficiency and excess did not affect cystatin C levels, adding to its usefulness in critically ill patients with ARF. Serum cystatin C is a useful detection marker of ARF, and may detect ARF one to two days earlier than creatinine. (Kidney Int 2004;66:1115-1122)
Surface Functionalization of Polypropylene Film via UV‐Induced Photografting of N‐Vinylpyrrolidone/Maleic Anhydride Binary Monomers
Authors: Xing Chang‐Min , Deng Jian‐Ping , Yang Wan‐Tai 
Published: May 2005

AbstractSummary: A polymeric surface with desirable wettability and versatile reactivity was facilely fabricated by UV‐induced surface photografting of N‐vinylpyrrolidone (NVP)/maleic anhydride (MAn) binary monomers, with polypropylene (PP) film as a model substrate. It was found that the photografting process of NVP/MAn is much faster than that of individual NVP or MAn; both the grafting efficiency (Eg) and grafting yield (Yg) reach a maximum at around 1:1 molar feed ratio of NVP to MAn. These results indicate that the electron donor‐acceptor monomers can synergistically promote surface photografting by a known charge‐transfer‐complex (CTC) mechanism. Moreover, the grafted NVP and MAn units cooperatively enhance the surface hydrophilicity; the water contact angle of the modified surface drastically decreases from the original 99.4° to less than 36° within 30 s of irradiation time. Subsequently, we demonstrated that the surface‐grafted succinic anhydride groups could readily perform a variety of organic reactions such as acidic/alkaline hydrolysis and esterification, which is expected to facilitate further surface functionalizations. Besides, the complexing reaction of surface pyrrolidone groups with iodine was investigated, which was followed by UV‐vis spectroscopy. The antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans show that this unique iodine‐complexated surface has desirable antimicrobial property.Surface photografting of NVP/MAn and post reactions of surface‐grafted anhydride groups and pyrrolidone groups.imageSurface photografting of NVP/MAn and post reactions of surface‐grafted anhydride groups and pyrrolidone groups.