bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific gravity and creatinine as corrections for variation in urine concentration in humans, gorillas, and woolly monkeys
Authors: White Brent C. , Jamison Keri M. , Grieb Cassie , Lally Drew , Luckett Cloe , Kramer Katie S. , Phillips Justin 
Published: July 2010

AbstractHormones excreted in the urine are widely used to assess the physiological and psychological condition of unrestrained animals. In order to control for variation in the water concentration of urine samples, the hormone concentration is often indexed to the concentration of creatinine. Because there are several problems with using creatinine, we have investigated the efficacy of specific gravity as an alternative basis for adjusting the hormone concentration in humans, gorillas, and woolly monkeys. In an experimental manipulation of human urine hydration, ten volunteers drank a water load proportional to body weight, and provided complete urine collection and saliva samples for four consecutive 20 min intervals. From the urine, we measured cortisol (radioimmunoassay), creatinine (colorimetric assay), and specific gravity (refractometer). Only cortisol was assayed from saliva. During 80 min following water ingestion, cortisol, creatinine, and specific gravity declined as urine became diluted; however, total cortisol excretion remained constant. Only cortisol concentration indexed to specific gravity accurately reflected the consistent cortisol excretion. Specific gravity and creatinine‐corrected cortisol values were highly correlated but were significantly different. Salivary cortisol provided evidence for the relative stability of serum cortisol. To determine the utility of these corrections in other primates, we compared specific gravity‐ and creatinine‐corrected cortisol in urine samples from captive gorillas (N=16) and woolly monkeys (N=8). As with the human study, the two corrections were strongly correlated in each species, but the means were different. Specific gravity correction was superior in revealing the circadian variation in cortisol. Am. J. Primatol. 72:1082–1091, 2010. © 2010 Wiley‐Liss, Inc.
Anwendung von Poly(ethylenglycol) beim Wirkstoff‐Transport: Vorteile, Nachteile und Alternativen
Authors: Knop Katrin , Hoogenboom Richard , Fischer Dagmar , Schubert Ulrich S. 
Published: July 2010

AbstractIm stetig wachsenden Feld der Polymer‐basierten Wirkstoff‐Transport‐Systeme gilt Poly(ethylenglycol) (PEG) als der Goldstandard für Stealth‐Polymere. Welche Eigenschaften PEG aufweist, die diese herausragende Stellung rechtfertigen, soll in diesem Aufsatz diskutiert werden. Die ersten PEGylierten Produkte erschienen bereits vor 20 Jahren auf dem Markt. Seither konnten viele Erkenntnisse in klinischen Untersuchungen gewonnen werden, allerdings wurden dabei nicht nur Vorteile festgestellt, sondern auch mögliche Nebenwirkungen und Komplikationen bei der Anwendung aufgedeckt. Diese möglichen Nachteile, die eine tiefergehende Untersuchung erfordern, können in folgende Kategorien unterteilt werden: Hypersensitivität, Veränderungen der Pharmakokinetik, toxische Nebenprodukte sowie ein Abbauparadoxon, das aus der Etherstruktur resultiert: Einerseits kann das Polymer relativ einfach unter mechanischer Belastung abgebaut werden, andererseits wird jedoch ein biologischer Abbau verhindert, was bei In‐vivo‐Anwendungen zur Anreicherung im Körper führen kann. Der Aufsatz diskutiert diese möglichen Nachteile und stellt alternative Polymere vor.
Functionalization of multi‐walled carbon nanotubes with poly(ε‐caprolactone) using click chemistry
Authors: Rana Sravendra , Yoo Hye Jin , Cho Jae Whan , Chun Byoung Chul , Park Jong Shin 
Published: July 2010

AbstractMulti‐walled carbon nanotubes (MWNTs) were covalently functionalized with poly(ε‐caprolactone) (PCL) using click chemistry. First, chlorine moiety‐containing PCL was synthesized by the copolymerization of α‐chloro‐ε‐caprolactone with ε‐caprolactone monomer using ring opening polymerization, and further converted to azide moiety‐containing PCL. The alkyne‐functionalized MWNTs were prepared with the treatment of p‐amino propargyl ether using a solvent free diazotization procedure. The covalent functionalization of alkyne‐derived MWNTs with azide moiety‐containing PCL was accomplished using Cu(I)‐catalyzed [3+2] Huisgen dipolar cycloaddition click chemistry. The PCL‐functionalization of MWNTs was confirmed by the measurements of Fourier transform infra‐red, NMR, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of fluorinated polyacrylate graft copolymers capable as water and oil repellent finishing agents
Authors: Tang Weiyi , Huang Yangen , Qing Feng‐Ling 
Published: July 2010

AbstractA facile method for preparation of fluorinated polyacrylate was developed. Novel multifunctional graft copolymer (GPF‐1, 2, 3) containing short fluoroalkyl side chains and reactive groups were successfully prepared by grafting fluoroalcohols to polyacrylate. The obtained products were characterized by 1H NMR, 19F NMR, FTIR, GPC, TGA, and XPS analyses. GPF‐1, 2, 3 exhibited very low surface free energy (17.77–25.81 mJ/m2). Cotton fabric treated by GPF‐1 had the highest water and oil repellency rating which was 100 and 6, respectively (AATCC test methods). The water and oil repellency rating was kept as 90 and 5, respectively, after 10 soaping cycles or 2 h uninterrupted soaping which indicated a very good washing durability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Development of the Tarsometatarsal Skeleton by the Lateral Fusion of Three Cylindrical Periosteal Bones in the Chick Embryo (Gallus gallus)
Authors: Namba Yuichi , Yamazaki Yosuke , Yuguchi Maki , Kameoka Shigeo , Usami Shinji , Honda Kazuya , Isokawa Keitaro 
Published: July 2010

AbstractAn avian tarsometatarsal (TMT) skeleton spanning from the base of toes to the intertarsal joint is a compound bone developed by elongation and lateral fusion of three cylindrical periosteal bones. Ontogenetic development of the TMT skeleton is likely to recapitulate the changes occurred during evolution but so far has received less attention. In this study, its development has been examined morphologically and histologically in the chick,Gallus gallus. Three metatarsal cartilage rods radiating distally earlier in development became aligned parallel to each other by embryonic day 8 (ED8). Calcification initiated at ED8 in the midshaft of cartilage propagated cylindrically along its surface. Coordinated radial growth by fabricating bony struts and trabeculae resulted in the formation of three independent bone cylinders, which further became closely apposed with each other by ED13 when the periosteum began to fuse in a back‐to‐back orientation. Bone microstructure, especially orientation of intertrabecular channels in which blood vasculature resides, appeared related to the observed rapid longitudinal growth. Differential radial growth was considered to delineate eventual surface configurations of a compound TMT bone, but its morphogenesis preceded the fusion of bone cylinders. Bony trabeculae connecting adjacent cylinders emerged first at ED17 in the dorsal and ventral quarters of intervening tissue at the mid‐diaphyseal level. Posthatch TMT skeleton had a seemingly uniform mid‐diaphysis, although the septa persisted between original marrow cavities. These findings provide morphological and histological bases for further cellular and molecular studies on this developmental process. Anat Rec 293:1527–1535, 2010. © 2010 Wiley‐Liss, Inc.
Variations in the Thickness and Composition of the Skin of the Giraffe
Authors: Sathar Farzana , Ludo Badlangana N. , Manger Paul R. 
Published: July 2010

AbstractThis study examined the skin of two 1‐ to 2‐year‐old male giraffes and one adult male, determining skin thickness and histological structure with reference to it functioning as a component of the features required for the maintenance of blood pressure, dermal armor, or thermoregulation. It has been argued that a tight skin surrounding the extremities of the giraffe aids in the movement of fluid against gravity, hence preventing pooling of blood and tissue fluid (edema), but the skin has also been implicated in the thermoregulatory capacities and defensive anatomy of many mammalian species. In one of the younger giraffes, one‐half of the skin was analyzed from which close to 170 sites were measured. In the other young and adult giraffes, spot tests to confirm the pattern observed in the fully analyzed individual were undertaken. It was discovered that the skin varied in thickness across the entire body and within regions of the body. Histological evaluation revealed that the skin was mostly collagenous, although interesting patterns of elastic fiber densities were also apparent. The skin in the neck and legs exhibited a morphology that may assist in cardiovascular regulation of blood flow to and from the head and legs, and the skin of the trunk and anterior neck has the possibility of functioning in a protective role. The analyses performed could not add any new data regarding the thermoregulatory role already described for giraffe skin. Anat Rec 293:1615–1627, 2010. © 2010 Wiley‐Liss, Inc.
Stalled replication forks: Making ends meet for recognition and stabilization
Authors: Masai Hisao , Tanaka Taku , Kohda Daisuke 
Published: July 2010

AbstractIn bacteria, PriA protein, a conserved DEXH‐type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA‐binding property allows it to recognize and stabilize stalled forks and the structures derived from them. Cells must cope with fork stalls caused by various replication stresses to complete replication of the entire genome. Failure of the stalled fork stabilization process and eventual restart could lead to various forms of genomic instability. The low viability of priA null cells indicates a frequent occurrence of fork stall during normal growth that needs to be properly processed. PriA specifically recognizes the 3′‐terminus of the nascent leading strand or the invading strand in a displacement (D)‐loop by the three‐prime terminus binding pocket (TT‐pocket) present in its unique DNA binding domain. Elucidation of the structural basis for recognition of arrested forks by PriA should provide useful insight into how stalled forks are recognized in eukaryotes.
Transcriptional and translational control of C/EBPs: The case for “deep” genetics to understand physiological function
Authors: Nerlov Claus 
Published: July 2010

AbstractThe complexity of organisms is not simply determined by the number of their genes, but to a large extent by how gene expression is controlled. In addition to transcriptional regulation, this involves several layers of post‐transcriptional control, such as translational repression, microRNA‐mediated mRNA degradation and translational inhibition, alternative splicing, and the regulated generation of functionally distinct gene products from a single mRNA through alternative use of translation initiation sites. Much progress has been made in describing the molecular basis for these gene regulatory mechanisms. However, it is now a major challenge to translate this knowledge into deeper understanding of the physiological processes, both normal and pathological, that they govern. Using the C/EBP family of transcription factors as an example, the present review describes recent genetic experiments addressing this general problem and discusses how the physiological importance of newly discovered regulatory mechanisms might be determined.
What an epigenome remembers
Authors: Lange Ulrike C. , Schneider Robert 
Published: July 2010

AbstractDuring mammalian development, maintenance of cell fate through mitotic divisions require faithful replication not only of the DNA but also of a particular epigenetic state. Germline cells have the capacity of erasing this epigenetic memory at crucial times during development, thereby resetting their epigenome. Certain marks, however, appear to escape this reprogramming, which allows their transmission to the offspring and potentially guarantees transgenerational epigenetic inheritance. Here we discuss the molecular requirements for faithful transmission of epigenetic information and our current knowledge about the transmission of epigenetic information through generations.
Aromatic Ring Strain in Arylselenenyl Bromides: Role in Facile Synthesis of Selenenate Esters via Intramolecular Cyclization
Authors: Selvakumar K. , Singh Harkesh B. , Butcher Ray J. 
Published: July 2010

AbstractThe synthesis and reactivity of 2,6‐disubstituted arylselenium compounds derived from 2‐bromo‐5‐tert‐butylisophthalic acid (43) are described. The syntheses of bis(5‐tert‐butylisophthalic acid dimethyl ester)diselenide (46) and bis(5‐tert‐butylisophthalic acid diisopropyl ester)diselenide (47) have been achieved by the reaction of the corresponding ester precursors with disodium diselenide. Reduction of diselenide 46 with lithium aluminum hydride affords 2,2′‐bis(5‐tert‐butylbenzene‐1,3‐dimethanol)diselenide (53). Diselenides 46 and 47 exhibit intramolecular Se⋅⋅⋅O interaction. Compound 53 does not show any intramolecular Se⋅⋅⋅O interaction. The anomalous Se⋅⋅⋅O nonbonded coordination observed in the single‐crystal X‐ray structures of compounds 46, 47 and 53 is compared and contrasted. The corresponding selenenyl bromides 54 and 55, derived from the reaction of diselenides 46 and 47 with bromine, are quite stable in the solid state. However, they undergo hydrolysis and subsequent intramolecular cyclization upon heating or after having been kept in solution over a period of time to give the corresponding selenenate esters 56 and 57. The X‐ray crystallographic study and density functional theory calculations on 54 at the B3LYP/6‐31G(d) level of theory indicate a significant distortion in planarity of the aromatic ring. Glutathione peroxidase‐like activities of diselenides 46 and 47 and their selenenate esters 56 and 57 have been studied both by thiophenol and bioassay methods. The very low glutathione peroxidase‐like activity of the diselenides (46 and 47) and their selenenate esters (56 and 57) in the thiophenol assay is attributed to the presence of the relatively strong Se⋅⋅⋅O intramolecular interaction in the selenenyl sulfide intermediates. The interaction retards the catalytic activity through both thiol exchange and an intramolecular cyclization reaction.
[FeIII(F20‐tpp)Cl] Is an Effective Catalyst for Nitrene Transfer Reactions and Amination of Saturated Hydrocarbons with Sulfonyl and Aryl Azides as Nitrogen Source under Thermal and Microwave‐Assisted Conditions
Authors: Liu Yungen , Che Chi‐Ming 
Published: July 2010

Abstract[FeIII(F20‐tpp)Cl] (F20‐tpp=meso‐tetrakis(pentafluorophenyl)porphyrinato dianion) is an effective catalyst for imido/nitrene insertion reactions using sulfonyl and aryl azides as nitrogen source. Under thermal conditions, aziridination of aryl and alkyl alkenes (16 examples, 60–95 % yields), sulfimidation of sulfides (11 examples, 76–96 % yields), allylic amidation/amination of α‐methylstyrenes (15 examples, 68–83 % yields), and amination of saturated CH bonds including that of cycloalkanes and adamantane (eight examples, 64–80 % yields) can be accomplished by using 2 mol % [FeIII(F20‐tpp)Cl] as catalyst. Under microwave irradiation conditions, the reaction time of aziridination (four examples), allylic amination (five examples), sulfimidation (two examples), and amination of saturated CH bonds (three examples) can be reduced by up to 16‐fold (24–48 versus 1.5–6 h) without significantly affecting the product yield and substrate conversion.
Coordination‐Induced Spin Crossover (CISCO) through Axial Bonding of Substituted Pyridines to Nickel–Porphyrins: σ‐Donor versus π‐Acceptor Effects
Authors: Thies Steffen , Bornholdt Claudia , Köhler Felix , Sönnichsen Frank D. , Näther Christian , Tuczek Felix , Herges Rainer 
Published: July 2010

AbstractNickel‐porphyrins, with their rigid quadratic planar coordination framework, provide an excellent model to study the coordination‐induced spin crossover (CISCO) effect because bonding of one or two axial ligands to the metal center leads to a spin transition from S=0 to S=1. Herein, both equilibrium constants K1S and K2, and for the first time also the corresponding thermodynamic parameters ΔH1S, ΔH2, ΔS1S, and ΔS2, are determined for the reaction of a nickel‐porphyrin (Ni‐tetrakis(pentafluorophenyl)porphyrin) with different 4‐substituted pyridines by temperature‐dependent NMR spectroscopy. The association constants K1S and K2 are correlated with the basicity of the 4‐substituted pyridines (R: OMe>H>CO2Et>NO2) whereas the ΔH1S values exhibit a completely different order (OMe<H>CO2Et>NO2). 4‐Nitropyridine exhibits the largest binding enthalpy, which, however, is overcompensated by a large negative binding entropy. We attribute the large association enthalpy of nitropyridine with porphyrin to the back donation of electrons from the Ni dxz and dyz orbitals into the π orbitals of pyridine, and the negative association entropy to a decrease in vibrational and internal rotation entropy of the more rigid porphyrin–pyridine complex. Back donation for the nitro‐ and cyanopyridine complexes is also confirmed by IR spectroscopy, and shows a shift of the N–O and C–N vibrations, respectively, to lower wave numbers. X‐ray structures of 2:1 complexes with nitro‐, cyano‐, and dimethylaminopyridine provide further indication of a back donation. A further trend has been observed: the more basic the pyridine the larger is K1S relative to K2. For nitropyridine K2 is 17 times larger than K1S and in the case of methoxypyridine K2 and K1S are almost equal.
Periodic Mesoporous Organosilica (PMO) Materials with Uniform Spherical Core‐Shell Structure
Authors: Haffer Stefanie , Tiemann Michael , Fröba Michael 
Published: July 2010

AbstractWe report the synthesis of monodisperse, spherical periodic mesoporous organosilica (PMO) materials. The particles have diameters between about 350 and 550 nm. They exhibit a regular core‐shell structure with a solid, non‐porous silica core and a mesoporous PMO shell with a thickness of approximately 75 nm and uniform pores of about 1.7 nm. The synthesis of the core and the shell is carried out in a one‐pot, two‐stage synthesis and can be accomplished at temperatures between 25 and 100 °C. Higher synthesis temperatures lead to substantial shrinking of the solid core, generating an empty void between core and shell. This leads to interesting cavitation phenomena in the nitrogen physisorption analysis at 77.4 K.
Proaromaticity: Organic Charge‐Transfer Chromophores with Small HOMO–LUMO Gaps
Authors: Wu Yi‐Lin , Bureš Filip , Jarowski Peter D. , Schweizer W. Bernd , Boudon Corinne , Gisselbrecht Jean‐Paul , Diederich François 
Published: July 2010

AbstractNovel donor‐ and/or acceptor‐substituted cross‐conjugated carbocycles based on quinoids or expanded quinoids, with radiaannulene perimeters, were prepared and investigated to validate proaromaticity as a concept for reducing HOMO–LUMO gaps in push–pull chromophores. Analyses of IR, 1H NMR, and UV/Vis/NIR spectra in conjunction with molecular structures determined by X‐ray diffraction show that these push–pull quinoids have significant charge‐separated ground states. This feature results in small optical gaps (near IR region) and diatropic magnetic environments inside the carbocycles, as suggested by nucleus‐independent chemical shift (NICS) calculations. The NICS results, together with the bond‐length analysis of the quinoid spacers, provide strong support that proaromaticity, that is, aromatized zwitterionic mesomeric contributions in the ground state, is effective. A push–pull tetrakis(ethynediyl)‐expanded quinoid chromophore represents the first proaromatic radiaannulene.
Nanostructure‐Directed Physisorption vs Chemisorption at Semiconductor Interfaces: The Inverse of the HSAB Concept
Authors: Gole James L. , Ozdemir Serdar 
Published: July 2010

AbstractA concept, complementary to that of hard and soft acid–base interactions (HSAB‐dominant chemisorption) and consistent with dominant physisorption to a semiconductor interface, is presented. We create a matrix of sensitivities and interactions with several basic gases. The concept, based on the reversible interaction of hard‐acid surfaces with soft bases, hard‐base surfaces with soft acids, or vice versa, corresponds 1) to the inverse of the HSAB concept and 2) to the selection of a combination of semiconductor interface and analyte materials, which can be used to direct a physisorbed vs chemisorbed interaction. The technology, implemented on nanopore coated porous silicon micropores, results in the coupling of acid–base chemistry with the depletion or enhancement of majority carriers in an extrinsic semiconductor. Using the inverse‐HSAB (IHSAB) concept, significant and predictable changes in interface sensitivity for a variety of gases can be implemented. Nanostructured metal oxide particle depositions provide selectivity and complement a highly efficient electrical contact to a porous silicon nanopore covered microporous interface. The application of small quantities (much less than a monolayer) of nanostructured metals, metal oxides, and catalysts which focus the physisorbtive and chemisorbtive interactions of the interface, can be made to create a range of notably higher sensitivities for reversible physisorption. This is exemplified by an approach to reversible, sensitive, and selective interface responses. Nanostructured metal oxides developed from electroless gold (AuxO), tin (SnO2), copper (CuxO), and nickel (NiO) depositions, nanoalumina, and nanotitania are used to demonstrate the IHSAB concept and provide for the detection of gases, including NH3, PH3, CO, NO, and H2S, in an array‐based format to the sub‐ppm level.
Doped TiO2 and TiO2 Nanotubes: Synthesis and Applications
Authors: Nah Yoon‐Chae , Paramasivam Indhumati , Schmuki Patrik 
Published: July 2010

AbstractTiO2 is one of the most investigated compounds in contemporary materials science. Due to a set of virtually unique electronic properties, it finds intense use in photoelectrochemical applications such as photocatalysis or solar cells. The main drawback in view of direct exploitation of solar‐light‐based effects is its large band gap of >3 eV. Visible‐light‐activated TiO2 can be prepared by doping (band‐gap engineering) through incorporation or decoration with other metal ions, nonmetal ions, and semiconductors. Most recently, efforts in TiO2 research have been even more intensified by the finding of self‐organized nanotubular oxide architectures that can be prepared by a simple but optimized anodization of Ti metal surfaces. These nanotubular geometries provide large potential for enhanced and novel functional features. This Review examines doped TiO2 and in particular TiO2 nanotubes. Various types of dopants, doping methods, and applications of modified TiO2 nanotubes are discussed.