bluuebunny/crossref_metadata_2025_split huggingface dataset:
The First Potent Subtype‐Selective Retinoid X Receptor (RXR) Agonist Possessing a 3‐Isopropoxy‐4‐isopropylphenylamino Moiety, NEt‐3IP (RXRα/β‐dual agonist)
Authors: Takamatsu Kayo , Takano Atsushi , Yakushiji Nobumasa , Morohashi Kazunori , Morishita Ken‐ichi , Matsuura Nobuyasu , Makishima Makoto , Tai Akihiro , Sasaki Kenji , Kakuta Hiroki 
Published: February 2008

AbstractRetinoid X receptor (RXR) agonists (rexinoids) are attracting much attention for their use in treatment of cancers, including tamoxifen‐resistant breast cancer and taxol‐resistant lung cancer, and metabolic disease. However, known RXR agonists have a highly lipophilic character. In addition, no subtype‐selective RXR agonists have been found. We previously reported an RXRα‐preferential agonist 4‐[N‐methanesulfonyl‐N‐(5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydro‐2‐naphthyl)amino]benzoic acid (6 a). The RXR agonistic activity is much less than that of well‐known RXR agonists. To develop potent, less‐lipophilic, and subtype‐selective RXR agonists, we created new RXR agonists possessing alkoxy and isopropyl groups as a lipophilic domain of the common structure of well‐known RXR agonists. As a result, compounds possessing branched alkoxy groups, 6‐[N‐ethyl‐N‐(3‐isopropoxy‐4‐isopropylphenyl)amino]nicotinic acid (NEt‐3IP: 7 a) and 6‐[N‐ethyl‐N‐(3‐isobutoxy‐4‐isopropylphenyl)amino]nicotinic acid (NEt‐3IB: 7 c), showed RXR agonistic activity as potent as, or more potent than, the activities of representative RXR agonists. Moreover, NEt‐3IP (7 a) was found to be the first RXRα/β‐selective (or RXRα/β‐dual) agonist. Being potent, less lipophilic, and having RXR subtype‐selective activity, NEt‐3IP (7 a) is expected to become a new drug candidate and to be a useful biological tool for clarifying each RXR subtype function.
Colour matching experiments with RGB‐LEDs
Authors: Csuti P. , Schanda J. 
Published: February 2008

AbstractCIE colorimetry breaks down when lights produced by narrow band RGB‐LEDs are matched with broad‐band lights. A colour matching experiment was set up and matches in a number of parts of the chromaticity diagram have been made, to determine the magnitude of the discrepancy. Differences between visual and instrumental matches increase as one moves in the chromaticity diagram from yellowish white lights toward greenish and bluish lights.CIE TC 1‐36 recently suggested newly defined cone fundamentals: Applying a transformation of these to a space similar to the CIE XYZ space enables a much better prediction of the matches to be made. The difference between the visual match and its instrumental prediction decreases by a factor of two or even more.The use of a cone fundamental based colorimetric system is recommended for LED colorimetry. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 108–112, 2008
An integrated color‐appearance model using CIELUV and its applications
Authors: Nayatani Yoshinobu , Sakai Hideki 
Published: February 2008

AbstractA new type of color‐appearance model is presented together with its formulations. It is named In‐CAM(CIELUV), which means the integrated color‐appearance model using CIELUV space. Using the In‐CAM(CIELUV), we can integrate its fields of applications in both colorimetric engineering and artistic color design. Various applications are introduced in colorimetric and color design fields. The In‐CAM(CIELUV) connects directly colorimetric color space and perceptual Hue‐Tone color order systems. In other words, the In‐CAM (CIELUV) gives a colorimetric basis for Hue‐Tone system. The three color attributes in the In‐CAM(CIELUV) space are mutually independent. This is a very convenient feature for selecting color combinations. Some two‐color combinations selected systematically in the In‐CAM(CIELUV) space are shown. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 125–134, 2008
Uncertainty analysis for the NIST 0:45 Reflectometer
Authors: Early Edward A. , Nadal Maria E. 
Published: February 2008

AbstractSets of color tiles are available from the National Institute of Standards and Technology calibrated using the NIST 0:45 Reflectometer. The uncertainties associated with the measured values for the color tiles are an indispensable component of the calibration report that accompanies these tiles. A systematic, analytical approach developed previously was applied to the particular case of the reference instrument and color tile set, taking into account the operation and characteristics of the instrument and the spectral properties of the set. The primary sources of uncertainty were identified, and the resulting uncertainties in the color space values L*, a*, and b* were determined. In general, the uncertainties are lowest for those color tiles whose reflectance factors are nearly constant with wavelength. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 100–107, 2008
Unbinding Molecular Recognition Force Maps of Localized Single Receptor Molecules by Atomic Force Microscopy
Authors: Sotres Javier , Lostao Anabel , Wildling Linda , Ebner Andreas , Gómez‐Moreno Carlos , Gruber Hermann J. , Hinterdorfer Peter , Baró Arturo M. 
Published: February 2008

AbstractAtomic force microscopy is a technique capable to study biological recognition processes at the single‐molecule level. In this work we operate the AFM in a force‐scan based mode, the jumping mode, where simultaneous topographic and tip–sample adhesion maps are acquired. This approach obtains the unbinding force between a well‐defined receptor molecule and a ligand attached to the AFM tip. The method is applied to the avidin–biotin system. In contrast with previous data, we obtain laterally resolved adhesion maps of avidin–biotin unbinding forces highly correlated with single avidin molecules in the corresponding topographic map. The scanning rate 250 pixel s−1 (2 min for a 128×128 image) is limited by the hydrodynamic drag force. We are able to build a rupture‐force distribution histogram that corresponds to a single defined molecule. Furthermore, we find that due to the motility of the polymer used as spacer to anchor the ligand to the tip, its direction at rupture does not generally coincide with the normal to the tip–sample, this introduces an appreciable error in the measured force.
Kinin‐B2 receptor expression and activity during differentiation of embryonic rat neurospheres
Authors: Martins Antonio H. , Alves Janaína M. , Trujillo Cleber A. , Schwindt Telma T. , Barnabé Gabriela F. , Motta Fabiana L. T. , Guimaraes Alessander O. , Casarini Dulce E. , Mello Luiz E. , Pesquero João B. , Ulrich Henning 
Published: February 2008

AbstractNeural progenitor cells were isolated from rat fetal telencephalon and proliferate as neurospheres in the presence of EGF, FGF‐2, and heparin. In the absence of these growth factors, neurospheres differentiate into neurons, astrocytes, and oligodendrocytes. Using an embryonal carcinoma cell line as in vitro differentiation model, we have already demonstrated the presence of an autocrine loop system between kinin‐B2 receptor activity and secretion of its ligand bradykinin (BK) as prerequisites for final neuronal differentiation (Martins et al., J Biol Chem 2005; 280: 19576–19586). The aim of this study was to verify the activity of the kallikrein‐kinin system (KKS) during neural progenitor cell differentiation. Immunofluorescence studies and flow cytometry analysis revealed increases in glial fibrillary acidic protein and β‐3 tubulin expression and decrease in the number of nestin‐positive cells along neurospheres differentiation, indicating the transition of neural progenitor cells to astrocytes and neurons. Kinin‐B2 receptor expression and activity, secretion of BK into the medium, and presence of high‐molecular weight kininogen suggest the participation of the KKS in neurosphere differentiation. Functional kinin‐B2 receptors and BK secretion indicate an autocrine loop during neurosphere differentiation to neurons, astrocytes, and oligodendrocytes, reflecting events occurring during early brain development. © 2008 International Society for Analytical Cytology
Iron and Cobalt Complexes of 4‐Alkyl‐2,6‐diiminopyridine Ligands: Synthesis and Ethylene Polymerization Catalysis
Authors: Cámpora Juan , Naz A. Marcos , Palma Pilar , Rodríguez‐Delgado Antonio , Álvarez Eleuterio , Tritto Incoronata , Boggioni Laura 
Published: February 2008

AbstractA new methodology for selective alkylation of the 2,6‐diiminopyridine (pdi) ligands allows the ready synthesis of new derivatives displaying 2‐methyl‐2‐phenylpropyl (neophyl), benzyl, or allyl groups in the 4‐position of the pyridine ring. A set of Fe and Co complexes containing the new ligands have been synthesized and fully characterized. The presence of 4‐neophyl or ‐benzyl groups does not perturb the performance of the complexes as ethylene polymerization catalysts, but the introduction of the 4‐allyl group leads to the production of higher molecular weight polymers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Platinum(II) Complexes with the Diethyl Aminomethylphosphonate Ligand (amp): Characterization, Properties, and Unusual Solution Behavior
Authors: Cornacchia Daniele , Cerasino Leonardo , Pacifico Concetta , Natile Giovanni 
Published: February 2008

AbstractCisplatin is one of the most widely prescribed drugs for the treatment of solid tumors, even though its pharmacological potential is often limited by side effects (nephrotoxicity, neurotoxicity, alopecia) and a limited spectrum of activity. Overcoming these limitations is one of the most chased goals by researchers in the field of medicinal chemistry. Since phosphonates have a great selectivity for bone tissues, we have extended a previous study on a platinum(II) complex with a diethyl [(methylsulfinyl)methyl]phosphonate (smp) ligand, [PtCl2(S,O‐smp)], to another phosphonate ester ligand, diethyl aminomethylphosphonate (amp). Further interest in this investigation was generated by the observation that [PtCl2(S,O‐smp)] was capable of inhibiting matrix metalloproteinases (MMPs), which also play a role in tumor growth. The interaction of the amp ligand with the tetrachloroplatinate(II) anion resulted in the production of the mono‐ and bis(amp) adducts in which the ligand acts as a monodentate N‐coordinated species; however, no stable species with the chelating ligand could be isolated. A rationale for the different chelating abilities of amp and smp is offered. A solution of cis‐[PtCl2(N‐amp)2] in organic solvents is very stable if kept in the dark; if it is exposed to light, it undergoes a ready and clean cis/trans isomerization, affording the trans‐[PtCl2(N‐amp)2] complex. The compounds have been characterized by means of spectroscopic techniques (1H, 31P, and 195Pt NMR), ESI‐MS, and elemental analysis. In the case of trans‐[PtCl2(N‐amp)2], the X‐ray structure has revealed a peculiar in‐plane orientation of the amp ligand. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Lewis Acid Catalyzed Intermolecular Olefin Hydroamination: Scope, Limitation, and Mechanism
Authors: Cheng Xiaojuan , Xia Yuanzhi , Wei Hua , Xu Bin , Zhang Chongguang , Li Yahong , Qian Guimin , Zhang Xiaohua , Li Kai , Li Wu 
Published: February 2008

AbstractIntermolecular olefin hydroamination was studied by various Lewis acids. The results of ZrCl4, FeCl3, BiCl3, and AlCl3 catalyzed reactions of norbornene with aromatic amines were compared, and BiCl3 was found to be the most effective catalyst to give high yields for various amines, whereas ZrCl4 could promote the reactions at relatively low temperatures. The FeCl3 catalyzed reactions were the most chemoselective and excellent yields could be achieved for certain amines by using AlCl3. A carbocation mechanism was proposed, and the controllable syntheses of allylamine and tetrahydroquinoline from isoprene and 2,5‐dichloroaniline were achieved by application of this mechanism. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Convenient Synthesis of Furanose‐Free D‐Fucose Per‐O‐Acetates and a Precursor for Anthrose
Authors: Hou Shujie , Kováč Pavol 
Published: February 2008

AbstractMethyl 3,4‐O‐isopropylidene‐α‐ or β‐D‐galactopyranoside was iodinated with triiodoimidazole in the presence of triphenylphosphane and the corresponding 6‐deoxy‐6‐iodo derivatives 5 or 6, respectively, were converted to furanose‐free 1,2,3,4‐tetra‐O‐acetyl‐α,β‐D‐fucopyranose. A key intermediate for chemical synthesis of anthrose, a constituent of the tetrasaccharide of major glycoprotein of Bacillus anthracis exosporium, 1‐O‐acetyl‐4‐azido‐2‐O‐benzoyl‐3‐O‐benzyl‐4,6‐dideoxy‐α,β‐D‐glucopyranose, was synthesized from 5 or 6 in 7 steps. The latter was readily converted into the corresponding 1‐O‐trichloroacetimidate.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Palladium‐Catalysed Cross‐Coupling Reactions of Triorganoindium Reagents with Alkenyl Halides
Authors: Riveiros Ricardo , Saya Lucía , Pérez Sestelo José , Sarandeses Luis A. 
Published: February 2008

AbstractThe regio‐ and stereoselectivity of the palladium‐catalysed cross‐coupling reactions of indium organometallics withstereodefined 1‐haloalkenes and 1,1‐dihaloalkenes have been studied. Triorganoindium reagents (R3In; R = alkyl, alkenyl, aryl and alkynyl) can be stereospecifically coupled with stereodefined alkenyl iodides in good yields and short reaction times under palladium catalysis. Additionally, the palladium‐catalysed cross‐coupling reaction of R3In (90 mol‐%) with 1,1‐dibromo‐1‐alkenes gave dicoupling products in high yields. When the reaction was performed with 40 mol‐% of aryl‐, vinyl‐ and alkynylindium derivatives, trans‐selective monosubstitution products were obtained in moderate to good yields. These selective couplings were performed with [Pd2dba3]/P(2‐furyl)3 (1:1, 2 mol‐%) at 0 °C or, for 1,1‐dibromo‐1‐alkenes with an aromatic group in the β‐position, [Pd(DPEPhos)Cl2] (2 mol‐%) at room temperature as the catalytic system. The resulting (Z)‐monobromoalkenes can be further functionalized by cross‐coupling reaction with various R3In (R = alkyl, aryl and alkynyl) in the presence of [Pd(tBu3P)2] as catalyst, at room temperature, to provide trisubstituted olefins in good yields.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Long‐chained gemini surfactants for semipermanent wall coatings in capillary electrophoresis of proteins
Authors: Liu Qian , Yuan Jinbin , Li Yanqing , Yao Shouzhuo 
Published: February 2008

AbstractIn this paper, we presented the first example of using gemini surfactants as semipermanent coatings in CE for protein separation. These coatings are based on the self‐assembly of a series of cationic gemini surfactants, alkanediyl‐α,ω‐bis(dimethylalkylammonium bromide) (m‐s‐m), on the capillary wall. The coatings can keep stable for a long time without surfactant in the buffer, e.g., after the surfactants were removed from the buffer, the reversed EOF only decreased by 3.6 and 3.9% for 18‐2‐18 and 16‐2‐16 coatings over 60 min under continuous electrophoretic conditions. The coating stability increased with the alkyl chain length m. The double long chains of geminis (m ≥ 14) yielded a good coating stability; meanwhile, the spacer group acted as an EOF modifier. Thus, this bifunctional surfactant coating provided a new buffer‐independent method for EOF control. For 18‐s‐18 series, the best coating stability and largest EOF were obtained at s = 10. Ranging s from 3 to 10 yielded a linear fine‐tuning of EOF and thereby allowed the adjustment of the protein apparent mobility. Highly efficient separation (>500 000 plates/m) was achieved with all the 18‐s‐18 coatings. Excellent run‐to‐run and day‐to‐day reproducibility (RSD of migration time ≤0.7 and 4.3% for run‐to‐run and day‐to‐day assays, respectively) and fine recoveries (97.5–100.1%) of the protein samples indicated that the gemini semipermanent coatings were quite effective for the wall adsorption suppression of proteins.
Cationic surfactants for micellar electrokinetic chromatography: 2. Representative applications to acidic, basic, and hydrophobic analytes
Authors: Schnee Vincent P. , Palmer Christopher P. 
Published: February 2008

AbstractChanges in MEKC chemical selectivity that are induced by changes in the headgroup structure of cationic surfactants are examined. Separations of acidic, basic, and hydrophobic solutes are examined. The acidic analytes are comprised of methoxyphenols, which are of interest due to their prevalence in wood smoke. The basic solutes consist of compounds often found in forensic urine analysis, and represent typical basic pharmaceuticals. The hydrophobic solutes are six pharmaceutical corticosteroids used in replacement therapy of adrenocortical insufficiency and nonspecific treatment of inflammatory and allergic conditions. The role of the headgroup was found to be quite significant when analyzing acidic compounds with not all the surfactants being able to resolve all of the analytes. The headgroup also induced migration order switches among the acidic analytes. All of the surfactants examined here in were found to be suitable for the analysis of basic analytes with each surfactant providing unique selectivity. The hydrophobic solutes were separated best with the larger more hydrophobic surfactant headgroups. The steroid separation with these two surfactants was achieved without the use of organic modifiers or a mixed micellar phase.
Determination of Acetic Acid in Fermentation Broth by Gas‐Diffusion Technique
Authors: Tippkötter N. , Deterding A. , Ulber R. 
Published: February 2008

AbstractDue to the interfering effects of acetic acid in many fermentation processes, a gas‐diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV‐absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV‐measurement of acetic acid, are held back efficiently. Merely, the fermentation by‐products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time‐dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV‐detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user‐friendly and does not require any toxic or expensive reagents.
Statistical and biological definitions of “anatomically modern” humans: Suggestions for a unified approach to modern morphology
Authors: Pearson Osbjorn M. 
Published: February 2008

AbstractMuch of the recent literature on the origin of modern humans has been plagued by an inability of the participants in the debate to agree on what constitutes “anatomically modern” morphology. An upshot of this disagreement has been an ongoing set of debates over which specimens are or are not anatomically modern and whether various fossil specimens such as the Florisbad cranium, Vindija Neanderthals, Klasies River Mouth mandibles, or Skhul‐Qafzeh hominins, all of which arguably possess some supposedly “modern” traits, qualify as genuinely “modern.” Such decisions frequently have implications with regard to how we reconstruct later hominin phylogenies and, ultimately, how we reconstruct the behaviors, adaptations, and evolution of Middle‐Late Pleistocene African hominins and their contemporaries.
The origin of modern anatomy: By speciation or intraspecific evolution?
Authors: Bräuer Günter 
Published: February 2008

Abstract“Speciation remains the special case, the less frequent and more elusive phenomenon, often arising by default” (p 164).1Over the last thirty years, great progress has been made regarding our understanding ofHomo sapiensevolution in Africa and, in particular, the origin of anatomically modern humans. However, in the mid‐1970s, the whole process ofHomo sapiensevolution in Africa was unclear and confusing. At that time it was widely assumed that very archaic‐looking hominins, also called the “Rhodesioids,” which included the specimens from Kabwe (Zambia), Saldanha (South Africa), and Eyasi (Tanzania), were spread over wide parts of the continent as recently as 30,000 or 40,000 years ago. Yet, at the same time, there were also indications from the Omo Kibish skeletal remains (Ethiopia) and the Border Cave specimens (South Africa) that anatomically modern humans had already been present somewhat earlier than 100,000 years B.P.2,3Thus, it was puzzling how such early moderns could fit in with the presence of very archaic humans still existing in Eastern and Southern Africa only 30,000 years ago.
Homo in the middle pleistocene: Hypodigms, variation, and species recognition
Authors: Rightmire G. Philip 
Published: February 2008

AbstractIt is generally accepted that modern humans evolved in Africa. This consensus has emerged in the last two decades, as molecular evidence has been coupled with findings from paleontology and prehistory. Patterns of DNA variation in living populations, morphology of fossils, and archeological traces can all be read to show that our species has deep roots in Africa and began to disperse into other regions only late in the Pleistocene. There are still questions about the timing of these dispersals and the extent to which modern people replaced or exchanged genes with other, more archaic groups, but new problems are now coming more clearly into focus. These relate to the ancestry of Homo sapiens in the Middle Pleistocene. In this essay, I emphasize the evidence available from Middle Pleistocene localities in Africa and Europe, exploring variation among individuals, composition of hypodigms, species‐level taxonomy, and evolutionary relationships of the hominin populations. One obvious difficulty is that the fossils are scarce. For the most part, only incomplete crania are available from African localities. The record is more comprehensive for the Sima de los Huesos in Spain, but principally crania and jaws are known from other European sites. This means that skull traits and measurements must provide the basis for sorting individuals to groups and building differential diagnoses. For much of the material, dating is still poorly controlled, although a few of the most important assemblages can now be placed more securely within a Middle Pleistocene chronological framework. Despite these constraints, it is possible to point toward tentative solutions.
Unusual Loss of Substituents in the Course of Cyclization of Tetrahydrobilines to Dihydroporphyrins
Authors: Damke Jan‐Erik , Latos‐Grażyński Lechosław , Montforts Franz‐Peter 
Published: February 2008

AbstractMetallo‐tetrahydrobiline rac‐8 was prepared to investigate its cyclization directed to the formation of N‐confused chlorins. To achieve the site‐directed selectivity of the cyclization, the 2‐position of rac‐2 was activated by an electron‐withdrawing cyano function and its 1‐position was blocked by a methyl group. In spite of this provision, the cyclization occurred at the apparently blocked 1‐position with loss or migration of the methyl substituent.