bluuebunny/crossref_metadata_2025 huggingface dataset:
The Development of Obesity Begins at an Early Age in Captive Common Marmosets (Callithrix jacchus)
Authors: POWER MICHAEL L. , ROSS CORINNA N. , SCHULKIN JAY , TARDIF SUZETTE D.
Published: January 2012

Animal models to study the causes and consequences of obesity during infancy in humans would be valuable. In this study, we examine the patterns of fat mass gain from birth to 12 months in common marmosets (Callithrix jacchus). Lean and fat mass was measured by quantitative magnetic resonance at 1, 2, 6, and 12 months for 31 marmosets, 15 considered Normal and 16 considered Fat (>14% body fat) at 12 months. Animals were fed either the regular colony diet mix or a high‐fat variation. Subjects classified as Fat at 12 months already had greater lean mass (198.4 ± 6.2 g vs. 174.0 ± 6.8 g, P = 0.013) and fat mass (45.5 ± 5.0 g vs. 24.9 ± 3.4 g, P = .002) by 6 months. Body mass did not differ between groups prior to 6 months, however, by 1 month, Fat infants had greater percent body fat. Percent body fat decreased between 1 and 12 months in Normal subjects; in Fat subjects, it increased. The high‐fat diet was associated with body fat >14% at 6 months (P = 0.049), but not at 12 months. This shift was due to three subjects on the normal diet changing from Normal to Fat between 6 and 12 months. Although maternal prepregnancy adiposity did not differ, overall, between Normal and Fat subjects, the subjects Normal at 6 and Fat at 12 months all had Fat mothers. Therefore, diet and maternal obesity appear to have potentially independent effects that may also vary with developmental age. Although birth weight did not differ between groups, it was associated with fat mass gain from 1 to 6 months in animals with >14% body fat at 6 months of age (r = 0.612, P = 0.026); but not in 6‐month‐old animals with <14% body fat (r = –0.012, P = 0.964). Excess adiposity in captive marmosets develops by 1 month. Birth weight is associated with adiposity in animals vulnerable to obesity.
Why Aye‐Ayes See Blue
Authors: MELIN AMANDA D. , MORITZ GILLIAN L. , FOSBURY ROBERT A. E. , KAWAMURA SHOJI , DOMINY NATHANIEL J.
Published: January 2012

The capacity for cone‐mediated color vision varies among nocturnal primates. Some species are colorblind, having lost the functionality of their short‐wavelength‐sensitive‐1 (SWS1) opsin pigment gene. In other species, such as the aye‐aye (Daubentonia madagascariensis), the SWS1 gene remains intact. Recent studies focused on aye‐ayes indicate that this gene has been maintained by natural selection and that the pigment has a peak sensitivity (λmax) of 406 nm, which is ∼20 nm closer to the ultraviolet region of the spectrum than in most primates. The functional significance behind the retention and unusual λmax of this opsin pigment is unknown, and it is perplexing given that all mammals are presumed to be colorblind in the dark. Here we comment on this puzzle and discuss recent findings on the color vision intensity thresholds of terrestrial vertebrates with comparable optics to aye‐ayes. We draw attention to the twilight activities of aye‐ayes and report that twilight is enriched in short‐wavelength (bluish) light. We also show that the intensity of twilight and full moonlight is probably sufficient to support cone‐mediated color vision. We speculate that the intact SWS1 opsin pigment gene of aye‐ayes is a crepuscular adaptation and we report on the blueness of potential visual targets, such as scent marks and the brilliant blue arils of Ravenala madagascariensis.
Adrenal androgen production in catarrhine primates and the evolution of adrenarche
Authors: Bernstein Robin M. , Sterner Kirstin N. , Wildman Derek E.
Published: January 2012

Adrenarche is a developmental event involving differentiation of the adrenal gland and production of adrenal androgens, and has been hypothesized to play a role in the extension of the preadolescent phase of human ontogeny. It remains unclear whether any nonhuman primate species shows a similar suite of endocrine, biochemical, and morphological changes as are encompassed by human adrenarche. Here, we report serum concentrations of the adrenal androgens dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) measured in 698 cross‐sectional and mixed longitudinal serum samples from catarrhine primates ranging from 0.6 to 47 years of age. DHEAS in Pan is most similar to that of humans in both age‐related pattern and absolute levels, and a transient early increase appears to be present in Gorilla. DHEA levels are highest in Cercocebus, Cercopithecus, and Macaca. We also tested for evidence of adaptive evolution in six genes that code for proteins involved in DHEA/S synthesis. Our genetic analyses demonstrate the protein‐coding regions of these genes are highly conserved among sampled primates. We describe a tandem gene duplication event probably mediated by a retrotransposon that resulted in two 3‐β‐hydroxysteroid dehydrogenase/Delta 5‐Delta 4 genes (HSD3B1 and HSD3B2) with tissue specific functions in catarrhines. In humans, HSD3B2 is expressed primarily in the adrenals, ovary, and testis, while HSD3B1 is expressed in the placenta. Taken together, our findings suggest that while adrenarche has been suggested to be unique to hominoids, the evolutionary roots for this developmental stage are more ancient. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Testing Bergmann's rule and the resource seasonality hypothesis in Malagasy primates using GIS‐based climate data
Authors: Kamilar Jason M. , Muldoon Kathleen M. , Lehman Shawn M. , Herrera James P.
Published: January 2012

We tested four major hypotheses on the ecological aspects of body mass variation in extant Malagasy strepsirrhines: thermoregulation, resource seasonality/scarcity, resource quality, and primary productivity. These biogeographic hypotheses focus on the ecological aspects of body mass variation, largely ignoring the role of phylogeny for explaining body mass variation within lineages. We tested the independent effects of climate and resource‐related variables on variation in body mass among Malagasy primates using recently developed comparative methods that account for phylogenetic history and spatial autocorrelation. We extracted data on lemur body mass and climate variables for a total of 43 species from 39 sites. Climatic data were obtained from the WorldClim database, which is based on climate data from weather stations compiled around the world. Using generalized linear models that incorporate parameters to account for phylogenetic and spatial autocorrelation, we found that diet and climate variables were weak predictors of lemur body mass. Moreover, there was a strong phylogenetic effect relative to the effects of space on lemur body mass in all models. Thus, we failed to find support for any of the four hypotheses on patterns of geography and body mass in extant strepsirrhines. Our results indicate that body mass has been conserved since early in the evolutionary history of each genus, while species diversified into different environmental niches. Our findings are in contrast to some previous studies that have suggested resource and climate related effects on body mass, though these studies have examined this question at different taxonomic and/or geographic scales. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Enamel thickness in Bornean and Sumatran orangutan dentitions
Authors: Smith Tanya M. , Kupczik Kornelius , Machanda Zarin , Skinner Matthew M. , Zermeno John P.
Published: January 2012

Dental enamel thickness has received considerable attention in ecological models of the adaptive significance of primate morphology. Several authors have theorized that the degree of enamel thickness may reflect selective pressures related to the consumption of fallback foods (dietary items that may require complex processing and/or have low nutritional value) during times of preferred food scarcity. Others have speculated that enamel thickness reflects selection during mastication of foods with particular material properties (i.e., toughness and hardness). Orangutans prefer ripe fruit when available, but show interspecific and sex differences in the consumption of fallback foods (bark, leaves, and figs) and other preferred foods (certain seeds). Bornean orangutans (Pongo pygmaeus) have also been reported to masticate more mechanically demanding foods than Sumatran orangutans (Pongo abelii). To test these ecological models, we assessed two‐dimensional enamel thickness in orangutan full dentitions using established histological and virtual quantification methods. No significant differences in average enamel thickness (AET) were found between species. We found significant differences in the components of enamel thickness indices between sexes, with males showing greater enamel‐dentine junction lengths and dentine core areas, and thus relatively thinner enamel than females. Comparisons of individuals of known sex and species revealed a dentition‐wide trend for Bornean females to show greater AET than Sumatran females. Differences between small samples of males were less evident. These data provide only limited support for ecological explanations of enamel thickness patterns within great ape genera. Future studies of dietary ecology and enamel thickness should consider sex differences more systematically. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Stability or variation? Patterns of lactase gene and its enhancer region distributions in Brazilian Amerindians
Authors: Friedrich Deise C. , Callegari‐Jacques Sidia M. , Petzl‐Erler M. Luiza , Tsuneto Luiza , Salzano Francisco M. , Hutz Mara H.
Published: January 2012

Lactase persistence (LP) is the phenotypic trait in which lactase secretion is maintained during adulthood. LP is due to mutations in the LCT enhancer region, located 14‐kb upstream of the gene. In Europeans, the −13910*T allele is associated with LP. In Africans this allele is rare while other mutations in this same region were related to LP. The LCT is highly polymorphic in human populations, but so far Brazilian Amerindians had not been investigated for these polymorphisms or for the presence of LP mutations. We describe the genetic diversity of the LCT region and the presence of LP enhancer mutations in four native Brazilian populations (Guarani‐Kaiowá, Guarani–Ñandeva, Kaingang, and Xavante). Twelve polymorphisms were genotyped by PCR‐based methods. The −13910*T allele varied from 0.5% in the Xavante to 7.6% in the Guarani–Ñandeva. These frequencies probably derive from European sources and they correlate with non‐native admixture proportions previously estimated for these groups. But since admixture is virtually absent in the Xavante, we suggest that the presence of the LP allele could have been determined by a de novo mutation. No other mutations in the −14 kb enhancer region were found. The LCT was highly polymorphic in the present sample showing 15 haplotypes with a heterogeneous distribution among the four Amerindian populations. This diversity could be due to drift, as indicated by the neutrality test performed. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Allenes in Catalytic Asymmetric Synthesis and Natural Product Syntheses
Authors: Yu Shichao , Ma Shengming
Published: January 2012

Allenes are the simplest class of cumulenes, with two contiguous CC bonds, and show unique physical and chemical properties. These features make allenes particularly attractive in modern organic chemistry. In this Review, attention is paid to the advances made in catalytic asymmetric synthesis and natural product syntheses based on well‐established reactions of allenes, such as propargylation, addition, cycloaddition, cycloisomerization, cyclization, etc., with or without catalysts. Their versatile reactivity, substituent‐loading ability, axial to center chirality transfer, and controllable selectivity allow access to target molecules by unique and efficient approaches. The main topics in this Review are presented with selected examples from 2003 to 2011.
Synthesis of liquefied corn barn‐based epoxy resins and their thermodynamic properties
Authors: Zhang Wenming , Zhang Yucang , Zhao Defeng
Published: January 2012

The liquefied corn barn‐based epoxy resin (LCBER) was synthesized through the glycidyl etherification reaction from liquefied corn barn (LCB), which has groups of bound phenol, and epichlorohydrin under alkali conditions. The average molecular weights of LCB and LCBER in various liquefaction conditions were examined. The thermodynamic properties of thermosetting resin cured by polyamide‐650 (PA‐650) were evaluated. It was found that the macromolecular chain and epoxy function of the resins would be a dominant factor for crosslinking density and properties of the cured LCBER. The cured liquefied CB‐based epoxy resin (LCBER‐30) using the corresponding LCB at 30 min (LCB‐30) as raw materials had much macromolecular exhibited higher glass‐transition and decomposition temperatures at 5% weight loss (Td), but worse shear strength in comparison with the other LCBER ones. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of organic peroxide and polymer chain structure on mechanical and dynamic mechanical properties of sisal fiber reinforced polyethylene composites
Authors: Ahmad E. E. M. , Luyt A. S.
Published: January 2012

Three types of polyethylene (PE), low‐density PE (LDPE), linear low‐density PE (LLDPE), and high‐density PE (HDPE) were used as polymer matrices to prepare untreated as well as dicumyl peroxide (DCP) treated sisal fiber composites. The effect of polymer chain structure, addition of DCP, and sisal fiber loadings on the mechanical and dynamic mechanical properties of the composite was investigated in this study. It was found that the extent of improvement in tensile properties of the composite samples varied with respect to the polymer molecular characteristics. The elongation at break for all the composites decreased significantly. Young's modulus and the tensile strength of the treated LDPE and LLDPE composites increased significantly compared with the untreated composites, whereas Young's modulus of the treated HDPE samples decreased observably compared with the untreated samples. DCP treatment, however, did not change the tensile strength of HDPE and its composites. The storage modulus results for all the PE composites correlate well with the tensile testing results. In the case of the LDPE and LLDPE samples, the curves of the mechanical loss factor (tan δ) show a clear relaxation around −18°C, which shifted to higher temperature in the treated composites, whereas for HDPE this transition was not seen. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The role of oxidation compounds in biofilm growth on polyethylene geomembrane barriers used in landfill
Authors: Pons C. , Richaud E. , Bouchez T. , Mazeas L. , Farcas F. , Fayolle B.
Published: January 2012

In a model study, polyethylene was preoxidized and incubated for a period of 7 months at 40°C in two different municipal solid waste leachates. During the postexperimental analyses, specific attention was paid to the carbonyl species and carboxylic acid depletion during the environmental exposure because it is well known that carboxylic acids are believed to be a potential substrate for the development of microorganisms. The results showed that the carbonyl as well as the carboxylic acid depletion observed follows first‐order kinetics. The biofilm formation was characterized using a suite of analytical techniques, and its formation was compared with the carboxylic acid and carbonyl depletion profile. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Miscibility studies of hydroxypropyl cellulose/poly(vinyl pyrrolidone) in dilute solutions and solid state
Authors: Reddy K. Sudarsan , Prabhakar M. N. , Reddy V. Nagamaheswara , Sathyamaiah G. , Maruthi Y. , Subha M. C. S. , Chowdoji Rao K.
Published: January 2012

The miscibility of hydroxypropyl cellulose (HPC) and poly(vinyl pyrrolidone) (PVP) blends in aqueous solutions was studied using viscosity, ultrasonic velocity, and refractive index techniques at 30°C. The interaction parameters ΔB, μ, and α calculated from viscosity using Sun and Chee methods indicated the miscibility of this blend. This was further confirmed by ultrasonic and refractive index results. The HPC/PVP blend films are prepared by solution casting method and are analyzed by differential scanning calorimetry, X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopic techniques that confirmed the complete miscibility. This miscibility is due to the strong intermolecular H‐bonding interactions between OH groups of HPC and CO groups of PVP. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
High dielectric permittivity and percolative behavior of polyvinyl alcohol/potassium dihydrogen phosphate composites
Authors: Uddin Md Jamal , Sannigrahi J. , Masud Md G. , Bhadra D. , Chaudhuri B. K.
Published: January 2012

A new kind of anhydrous, transparent, and flexible potassium dihydrogen phosphate (KH2PO4 or KDP)/polyvinyl alcohol (PVA) composite in the form of film (0.10 mm) has been prepared by solution casting technique. KDP is well dispersed in the polymer matrix as observed from the microstructural studies. Frequency and temperature dependent dielectric properties of the composites have been studied with varying KDP concentrations. The PVA/KDP composite films exhibited extraordinarily high relative permittivity ε′ ∼ 430 (80 times higher compared with pure PVA and even higher than KDP) near the percolation threshold (ϕC = 2.5 wt % KDP) with low dielectric losses (∼ 0.15) at 1 kHz and room temperature. Such flexible, low loss and high dielectric permittivity material has enormous importance for application in devices. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Process feasibility and kinetic analysis of glass fiber‐reinforced vinyl ester/nano‐Al2O3 matrix composites for pultrusion
Authors: Sun Yun‐Yun , Chen Chin‐Hsing
Published: January 2012

This work presents a process developed to manufacture glass fiber‐reinforced vinyl ester (VE)/nano‐Al2O3 matrix composites by pultrusion method. The matrix prepolymer for pultrusion in this study was prepared from blends of VE, initiator (t‐butyl perbenzoate), and nano‐Al2O3. The process feasibility and kinetic analysis of the unidirectional glass fiber‐reinforced VE/nano‐Al2O3 matrix composites by pultrusion have been investigated. From the investigations of the long pot life of VE/nano‐Al2O3 matrix, the high reactivity of VE/nano‐Al2O3 matrix, and excellent fiber wet‐out of VE/nano‐Al2O3 matrix and glass fiber, it was found that the VE/nano‐Al2O3 matrix showed excellent process feasibility for pultrusion. A kinetic autocatalytic model, dα/dt = A exp(−E/RT)αm(1 − α)n, was proposed to describe the curing behavior of glass fiber‐reinforced VE/nano‐Al2O3 matrix composites. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans using a multiple regression technique. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of chitosan–zeolite composites
Authors: Wan Ngah W. S. , Teong L. C. , Wong C. S. , Hanafiah M. A. K. M.
Published: January 2012

Double crosslinked chitosan–zeolite (CZ‐2) and noncrosslinked chitosan–zeolite (CZ‐0) composites were prepared and characterized by using Fourier transform infrared (FTIR) spectrometer, surface area analyzer, scanning electron microscope coupled with energy dispersive X‐ray (SEM‐EDX) spectrometer, thermogravimetric analyzer (TGA), X‐ray diffraction analyzer (XRD) and carbon, hydrogen, nitrogen (CHN) analyzer. After crosslinking, CZ‐2 showed a reduction in surface area and CHN content in comparison to chitosan, zeolite, and CZ‐0. Crosslinking resulted in improved stability of CZ‐2 in distilled water, acetic acid and NaOH as CZ‐2 recorded the lowest percentage of swelling. XRD diffractograms confirmed the formation of composites as there was a marked difference in the peak intensity at 2θ = 19.8°. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Aggregation structure development and mechanical properties of biodegradable poly(butylene succinate‐co‐terephthalate) fibers
Authors: Luo Shengli , Li Faxue , Yu Jianyong , Cao Amin
Published: January 2012

Biodegradable poly(butylene succinate‐co‐terephthalate)(PBST) copolyester, with 70 mol % butylene terephthalate (BT), was melt‐spun into fibers at various take‐up velocities ranging from 2.0 to 4.0 km/min. The structure development and mechanical properties of the as‐spun PBST fibers were intensively investigated via birefringence, wide angle X‐ray diffraction (WAXD) measurement, tensile test, and cyclic stretch test. With increasing the take‐up velocity, the initial tensile modulus and breaking strength of PBST fibers increased, while elongation at break decreased. These were attributed to the increasing degree of orientation and crystallinity, which were resulted from the elevating tension of spinning line at higher take‐up velocity. To elucidate the effects of soft butylene succinate (BS) unit on the tensile and elastic properties of PBST fibers, poly(butylene terephthalate) (PBT) fibers were adopted as a comparison sample. The results showed that the combination of soft BS unit and hard BT unit for PBST fibers made contribution to the lower initial modulus, higher elongation at break and better elastic recovery than those of PBT fibers. Moreover, PBST fibers were found to undergo PBT‐like crystal form transition from α‐form to β‐form crystal structure under tension load through the measurement of WAXD. A relatively wider strain region for the crystal transition of PBST fibers also endowed them with higher elastic recoverability than PBT fibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Phosphoric acid doped polybenzimidazole membrane for high temperature PEM fuel cell
Authors: Ergun Dilek , Devrim Yilser , Bac Nurcan , Eroglu Inci
Published: January 2012

In the present study, phosphoric acid doped polybenzimidazole (PBI) membranes with potential applications in high temperature PEM fuel cells were investigated. PBI was synthesized by polycondensation of 3,3′‐diaminobenzidine and isophtalic acid in polyphosphoric acid. The formation of PBI was validated by H1‐NMR and elemental analysis. PBI membranes were prepared by solution casting method and immersed in phosphoric acid in order to provide ionic conductivity. The phosphoric acid doped membranes were used to prepare membrane electrode assemblies (MEA) for PEMFC operation. Gas diffusion layer (GDL) spraying method was used to prepare the electrodes. In order to determine optimum electrode structure, the effect of electrode preparation technique on fuel cell performances was studied. Two methods were applied in which the binder differs in the catalyst ink. In the first method, 5 wt % PBI solution was used as the binder. In the second method, polyvinylidene fluoride (PVDF) was used in addition to PBI as the binder in the catalyst ink. The MEA were tested in a single cell operating at 100°C without need for humidification of reactant gases. The observed maximum power output was increased considerably from 0.015 to 0.072 W/cm2 at 150°C when the binder of the catalyst was changed from PBI to PBI and PVDF mixture (PVDF : PBI = 3 : 1). A single cell was operated up to 160°C and the power outputs of 0.032 and 0.063 W/cm2 were obtained at operating temperatures of 125 and 160°C, respectively. The PVDF : PBI ratio was 1 : 3 in the catalyst ink at both temperatures. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electropolymerization and characterization of 3,4‐ethylenedioxy thiophene on glassy carbon electrode and study of ions transport of the polymer during redox process
Authors: Moradi Atefeh , Emamgolizadeh Abbas , Omrani Abdollah , Rostami Abbas Ali.
Published: January 2012

Poly(3,4‐ethylenedioxythiophene) (PEDOTh) films were deposited on glassy carbon (GC) electrodes from organic electrolytes containing the monomer in a solution of acetonitrile (AN). The effect of the supporting electrolyte used during electropolymerization, on the redox behavior, surface morphology, and degree of crystallinity of the films has been investigated by FTIR, cyclic voltammetry, and scanning electron microscopy (SEM) techniques. The use of LiPF6 leads to a higher electropolymerization efficiency and an increase of electroactivity and crystallinity of the polymer. On the basis of voltammetric studies of the Nernst and Butler–Volmer equations, we concluded that BF4−, ClO4−, and PF6− anions are the mobile species during the redox process of the PEDOTh films. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structure development and melt viscoelastic properties of PE/organoclay nanocomposite blown films
Authors: Abdolrasouli Mehdi H. , Behzadfar Ehsan , Nazockdast Hossein , Sharif Farhad
Published: January 2012

The effects of compatibilizer and the type of polyethylene (PE) matrix on structure development of PE/organoclay nanocomposite samples were investigated by means of X‐ray diffraction technique and transmission electron microscopy in conjunction with melt viscoelastic measurements. It was shown that the presence of compatibilizer plays a key role in determining the extent of intercalation and resulting structure development in both linear low‐density polyethylene (LLDPE) and low‐density polyethylene (LDPE). The LLDPE/organoclay nanocomposite samples exhibited a pronounced low‐frequency nonterminal storage modulus whose values were found to be greater than those of LDPE/organoclay nanocomposite samples. The percentage increase in storage modulus values for the compatibilized LLDPE/organoclay nanocomposite sample compared to the virgin LLDPE sample was 1080, while the percentage increase in storage modulus values for the compatibilized LDPE/organoclay nanocomposite sample compared to the virgin LDPE sample was 200, at frequency 0.1 s−1. The melt viscoelastic measurements performed on the nanocomposite blown film samples indicated that at higher draw‐down ratio the organoclay platelets and/or tactoids were aligned in the flow direction. Comparing the melt viscoelastic results obtained for annealed and unannealed nanocomposite blown film samples, it was demonstrated that the reorientation of the induced organoclay alignment, which led to network structure formation in the amorphous phase of PE, is very slow, and the time required to complete the reorientation was found to be longer than 3 h at annealing temperature (100°C). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Enhanced conductivity and fluorescence of polyaniline doped with Eu3+, Tb3+, and Y3+ ions
Authors: Zhang Jiali , Wang Hao , Yang Shimei , Wang Shaohui , Yang Shaoming
Published: January 2012

The doped polyaniline (PANI) with rare earth ions, which exhibits an increasing conductivity and strongly enhanced fluorescence emission, was prepared by dispersing PANI powder suspension in acetonitrile solution containing rare earth ions according to different mass ratios of rare earth ions to PANI at room temperature. The structure of the doped PANI was characterized by the spectra of FTIR, Raman, UV‐vis, and XRD. Red‐shifted change for the quinoid and benzenoid stretching vibration is observed in IR and Raman spectra after doping rare earth cations, and UV‐vis absorption peak also presents a red‐shift, indicating that the doped PANI possesses a better delocalization of electrons along the mainchain backbone. The experimental data show that the electrical and optical behaviors of PANI strongly depend on the species of rare earth cations and their concentration. It is found that enhancing fluorescence for the doped PANI is observed by comparing with emeraldine base (EB). Moreover, the conductivity of the protonated PANI samples doped with Eu3+, Tb3+, and Y3+ ions, increases from 2.1 × 10−4 to 3.33 S cm−1, 1.50 × 10−1 S cm−1 and 2.26 × 10−1 S cm−1. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Covalent‐ionically crosslinked sulfonated poly(arylene ether sulfone)s bearing quinoxaline crosslinkages as proton exchange membranes
Authors: Chen Pei , Chen Xinbing , An Zhongwei
Published: January 2012

Crosslinkable sulfonated poly(arylene ether sulfone)s (SPAESs) were synthesized by copolymerization of 4,4′‐biphenol with 2,6‐difluorobenzil, 4,4′‐difluorodiphenyl sulfone, and 3,3′‐disulfonated‐4,4′‐difluorodiphenyl sulfone disodium salt. The corresponding covalent‐ionically crosslinked SPAESs were prepared via the cyclocondensation reaction of benzil moieties in polymer chain with 3,3′‐diaminobenzidine. The crosslinking significantly improved the membrane performance, that is, the crosslinked membranes had the lower membrane dimensional swelling, lower methanol permeability, and higher oxidative stability than the corresponding precursor membranes, with keeping the reasonably high proton conductivity. The crosslinked membrane (CS5) with measured ion exchange capacity of 1.47 meq g−1 showed a reasonably high proton conductivity of 112 mS cm−1 with water uptake of 42 wt % at 80°C, and exhibited a low methanol permeability of 2.1 × 10−7 cm2 s−1 for 32 wt % methanol solution at 25°C. The crosslinked SPAES membranes have potential for PEFC and DMFCs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Progress of Research in Cell‐in‐Cell Phenomena
Authors: Yang Yue‐Qin , Li Ji‐Cheng
Published: January 2012

The discovery of a nonphagocytotic process of cell‐in‐cell phenomena can be traced to over a century ago. However, its biological significance remains poorly understood. Three types of cell‐in‐cell phenomena have been described so far, termed “cannibalism,” “emperipolesis,” and “entosis.” These three kinds of cell‐in‐cell phenomena, apart from a common feature of one cell internal to another, are distinct both cytologically and biologically. In this review, we discussed them in their morphology, cell recognition, penetration mechanisms, and physiological roles, respectively. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
siRNA high‐throughput kinase library screen identifies protein kinase, DNA‐activated catalytic polypeptide to play a role in MyD88‐induced IFNA2 activation and IL‐8 secretion
Authors: Charlaftis Nikolaos , Fearon Douglas T. , Schoenemeyer Annett , Morley Peter J.
Published: January 2012

The discovery of RNA interference has led to the development of short interfering RNA (siRNA) screening, which has been widely used to study biological pathways. Here, we describe the development and validation of a system suitable to identify cellular genes involved in interferon A2 (IFNA2) promoter activation and interleukin (IL)‐8 secretion downstream of MyD88. Forty genes were identified. Five genes were selected for further study. One gene, protein kinase, DNA‐activated catalytic polypeptide (PRKDC), was confirmed to play a role in MyD88‐induced IFNA2 activation and IL‐8 secretion.
Effect of the timing of food intake on the absorption and bioavailability of carbamazepine immediate‐release tablets in beagle dogs
Authors: Xu Cai‐hong , Cheng Gang , Liu Yi , Tian Ye , Yan Jing , Zou Mei‐juan
Published: January 2012

The effect of dosing time on the bioavailability of carbamazepine immediate‐release (IR) tablets was investigated when administered to beagle dogs who were fasting, with co‐administration of food (Co‐food), and 0.5 h before food and 2 h after food. The study was conducted using a single dose of 200 mg (tablets/solution) with a 2 week washout period in a crossover design. Food intake significantly increased the rate and extent of tablet absorption. The Cmax (µg·ml−1, 8.13/3.65) and tmax (h, 1.83/0.92) were increased more than two‐fold and the AUC0‐24 (µg·h·ml−1, 20.09/8.19) was 2.5 times that of the values obtained under fasting conditions. The bioavailability of the tablets under fasting conditions was 91.2%, but increased to 223.5%, 182.8% and 148.4% in the Co‐food, 0.5 h before food and 2 h after food groups, respectively (p < 0.05). Although there was no significant difference in the Cmax or AUC0‐24 between the treatments with food, the absorption appeared to be reduced to some extent when the tablets were given 2 h after food. The oral bioavailability of CBZ IR tablets was significantly affected by the timing of the food intake. This is maybe favored by the fluctuations in the level of bile salts with the timing of food intake. To obtain acute therapy for a drug with narrow therapeutic window, attention should be given to the dosing time and food intake interactions. Copyright © 2012 John Wiley & Sons, Ltd.
In situ LTE exposure of the general public: Characterization and extrapolation
Authors: Joseph Wout , Verloock Leen , Goeminne Francis , Vermeeren Günter , Martens Luc
Published: January 2012

In situ radiofrequency (RF) exposure of the different RF sources is characterized in Reading, United Kingdom, and an extrapolation method to estimate worst‐case long‐term evolution (LTE) exposure is proposed. All electric field levels satisfy the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) reference levels with a maximal total electric field value of 4.5 V/m. The total values are dominated by frequency modulation (FM). Exposure levels for LTE of 0.2 V/m on average and 0.5 V/m maximally are obtained. Contributions of LTE to the total exposure are limited to 0.4% on average. Exposure ratios from 0.8% (LTE) to 12.5% (FM) are obtained. An extrapolation method is proposed and validated to assess the worst‐case LTE exposure. For this method, the reference signal (RS) and secondary synchronization signal (S‐SYNC) are measured and extrapolated to the worst‐case value using an extrapolation factor. The influence of the traffic load and output power of the base station on in situ RS and S‐SYNC signals are lower than 1 dB for all power and traffic load settings, showing that these signals can be used for the extrapolation method. The maximal extrapolated field value for LTE exposure equals 1.9 V/m, which is 32 times below the ICNIRP reference levels for electric fields. Bioelectromagnetics 33:466–475, 2012. © 2012 Wiley Periodicals, Inc.
Excitable behavior can explain the “ping‐pong” mode of communication between cells using the same chemoattractant
Authors: Goryachev Andrew B. , Lichius Alexander , Wright Graham D. , Read Nick D.
Published: January 2012

Here we elucidate a paradox: how a single chemoattractant‐receptor system in two individuals is used for communication despite the seeming inevitability of self‐excitation. In the filamentous fungus Neurospora crassa, genetically identical cells that produce the same chemoattractant fuse via the homing of individual cell protrusions toward each other. This is achieved via a recently described “ping‐pong” pulsatile communication. Using a generic activator‐inhibitor model of excitable behavior, we demonstrate that the pulse exchange can be fully understood in terms of two excitable systems locked into a stable oscillatory pattern of mutual excitation. The most puzzling properties of this communication are the sudden onset of oscillations with final amplitude, and the absence of seemingly inevitable self‐excitation. We show that these properties result directly from both the excitability threshold and refractory period characteristic of excitable systems. Our model suggests possible molecular mechanisms for the ping‐pong communication.
Physical and chemical aspects of stabilization of compounds in silk
Authors: Pritchard Eleanor M. , Dennis Patrick B. , Omenetto Fiorenzo , Naik Rajesh R. , Kaplan David L.
Published: January 2012

The challenge of stabilization of small molecules and proteins has received considerable interest. The biological activity of small molecules can be lost as a consequence of chemical modifications, while protein activity may be lost due to chemical or structural degradation, such as a change in macromolecular conformation or aggregation. In these cases, stabilization is required to preserve therapeutic and bioactivity efficacy and safety. In addition to use in therapeutic applications, strategies to stabilize small molecules and proteins also have applications in industrial processes, diagnostics, and consumer products like food and cosmetics. Traditionally, therapeutic drug formulation efforts have focused on maintaining stability during product preparation and storage. However, with growing interest in the fields of encapsulation, tissue engineering, and controlled release drug delivery systems, new stabilization challenges are being addressed; the compounds or protein of interest must be stabilized during: (1) fabrication of the protein or small molecule‐loaded carrier, (2) device storage, and (3) for the duration of intended release needs in vitro or in vivo. We review common mechanisms of compound degradation for small molecules and proteins during biomaterial preparation (including tissue engineering scaffolds and drug delivery systems), storage, and in vivo implantation. We also review the physical and chemical aspects of polymer‐based stabilization approaches, with a particular focus on the stabilizing properties of silk fibroin biomaterials. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 479–498, 2012.
Correlation of CT aortography measurements of infrarenal aortic aneurysms and body mass index in preprocedural evaluation for endovascular repair
Authors: Mladenovic Ana S. , Markovic Zeljko Z. , Hyodoh Hideki H. , Stosic‐Opincal Tatjana
Published: January 2012

The aim of this study is to analyze the morphological differences of infrarenal aortic aneurysms and common iliac arteries that are important for endovascular management between patients of different body mass index using 64 slice multidetector row CT aortography. This was a multicenter study of 100 patients (50 Europeans and 50 Japanese). All patients had risk factors, manifest symptoms, and ultrasound verified aneurysmal dilation of the infrarenal aorta. All examinations were performed on the same CT platform using the same post‐processing protocols. Due to the heterogeneity of the population, several statistical models were used. Significant differences were found in morphological parameters of infrarenal aorta in relation to BMI. In over one out of three patients with BMI less than 23, endovascular treatment is contraindicated due to the dimensions of the aneurysmal neck. Relative to BMI value, differences were found in transverse diameters of the medium part of the aneurysm and in the length of common iliac arteries. CT aortography performed on a 64 slice multidetector row CT platform provides precise and numerous data for the analysis of anatomical and pathological differences of infrarenal aortic aneurysms that are of crucial importance for the planning of treatment and the analysis of the differences relating to body habitus. Clin. Anat. 25:767–772, 2012. © 2012 Wiley‐Liss, Inc.
Base Pairing at the Abasic Site in DNA Duplexes and Its Application in Adenosine Aptasensors
Authors: Pang Yuanfeng , Xu Zhiai , Sato Yusuke , Nishizawa Seiichi , Teramae Norio
Published: January 2012

The binding of nucleosides to abasic site (AP site)‐containing DNA duplexes (AP‐DNAs) carrying complementary nucleosides opposite the AP site was investigated by thermal denaturation and isothermal titration calorimetric (ITC) experiments. Purine nucleosides show high affinities (Kd=14.1 μM for adenosine and 41.8 μM for guanosine) for binding to the AP‐DNAs, and the interactions are driven primarily by the enthalpy change, similarly to the case of DNA intercalators. In contrast, pyrimidine nucleosides do not show noticeable binding to the AP‐DNAs, thus suggesting that stacking interaction at the AP site plays a key role in the binding of purine nucleosides to the AP‐DNAs, as revealed by ITC measurements. Next, to apply an AP‐DNA as an aptasensor for adenosine, a competitive assay between adenosine and AP‐site‐binding fluorescent ligand was performed. The assay employs a fluorescent ligand, riboflavin, that binds to the AP site in a DNA duplex, thereby causing fluorescence quenching. By adding adenosine to the riboflavin/AP‐DNA complex, the binding of adenosine to the AP site causes release of riboflavin from the AP site, thereby resulting in restoration of riboflavin fluorescence. AP‐DNAs can serve as a new class of aptasensors—a limit of detection of 0.7 μM was obtained for adenosine. In contrast to conventional aptasensors for adenosine, the present method shows high selectivity for adenosine over the other nucleotides (AMP, ADP and ATP). The method does not require covalent labelling of fluorophores, and thus it is cost‐effective; finally, the method was successfully demonstrated to be applicable for the detection of adenosine in horse serum.
An Adaptable Luminescence Resonance Energy Transfer Assay for Measuring and Screening Protein–Protein Interactions and their Inhibition.
Authors: Yapici Engin , Reddy D. Rajasekhar , Miller Lawrence W.
Published: January 2012

Protein–protein interactions (PPIs) are central to biological processes and represent an important class of therapeutic targets. Here we show that the interaction between FK506‐binding protein 12 fused to green fluorescent protein (GFP‐FKBP) and the rapamycin‐binding domain of mTor fused to Escherichia coli dihydrofolate reductase (FRB‐eDHFR) can be sensitively detected (signal‐to‐background ratio (S/B)>100) and accurately quantified within an impure cell lysate matrix using a luminescence resonance energy transfer (LRET) assay. Ascomycin‐mediated inhibition of GFP‐FKBP–rapamycin–FRB‐eDHFR complex formation was also detected at high S/B ratio (>80) and Z′‐factor (0.89). The method leverages the selective, stable binding of trimethoprim (TMP)‐terbium complex conjugates to eDHFR, and time‐resolved, background‐free detection of the long‐lifetime (∼ms) terbium‐to‐GFP LRET signal that indicates target binding. TMP–eDHFR labeling can be adapted to develop high‐throughput screening assays and complementary, quantitative counter‐screens for a wide variety of PPI targets with a broad range of affinities that may not be amenable to purification.
Fluorescence spectroscopic determination of triglyceride in human serum with window genetic algorithm partial least squares
Authors: Kong Xiangzhen , Zhu Weihua , Zhao Zhimin , Li Xiangyan , Wang Hui , Chen Ran , Chen Chuchu , Zhu Feng , Guo Xiaoying
Published: January 2012

Fluorescence spectrum, as well as the first and second derivative spectra in the region of 220–900 nm, was utilized to determine the concentration of triglyceride in human serum. Nonlinear partial least squares regression with cubic B‐spline‐function‐based nonlinear transformation was employed as the chemometric method. Window genetic algorithms partial least squares (WGAPLS) was proposed as a new wavelength selection method to find the optimized spectra wavelengths combination. Study shows that when WGAPLS is applied within the optimized regions ascertained by changeable size moving window partial least squares (CSMWPLS) or searching combination moving window partial least squares (SCMWPLS), the calibration and prediction performance of the model can be further improved at a reasonable latent variable number. SCMWPLS should start from the sub‐region found by CSMWPLS with the smallest root mean squares error of calibration (RMSEC). In addition, WGAPLS should be utilized within the region of smallest RMSEC whether it is the sub‐region found by CSMWPLS or region combination found by SCMWPLS. Moreover, the prediction ability of nonlinear models was better than the linear models significantly. The prediction performance of the three spectra was in the following order: second derivative spectrum < original spectrum < first derivative spectrum. Wavelengths within the region of 300–367 nm and 386–392 nm in the first derivative of the original fluorescence spectrum were the optimized wavelength combination for the prediction model. Copyright © 2012 John Wiley & Sons, Ltd.
Porous YAG:Nd3+ Fibers with Excitation and Emission in the Human “NIR Optical Window” as Luminescent Drug Carriers
Authors: Ma Zhijun , Ji Huijiao , Tan Dezhi , Dong Guoping , Teng Yu , Zhou Jiajia , Qiu Jianrong
Published: January 2012

The design and preparation of luminescent drug carriers has been a prosperous area of research for many years. However, the excitation and/or emission wavelength of such luminescent drug carriers haven′t been optimized in the so‐called human “near infrared (NIR) optical window”, thus restricting their practical applications. Herein, we report the synthesis of electrospun porous YAG:Nd3+ (neodymium‐doped yttrium aluminum garnet) fibers with both excitation and emission in the “NIR optical window” as luminescent drug carriers. The YAG:Nd3+ porous fibers were characterized by SEM, TEM, XRD, scanning transmission electron microscopy–energy‐dispersive X‐ray spectroscopy (STEM‐EDX), and photoluminescence (PL). Ibuprofen (IBU) was used as a model drug to evaluate the drug‐loading capacities and release profiles of the samples. BMSCs (bone mesenchymal stem cells) were used as model human cells to investigate cytotoxicity. Our results indicated that the YAG:Nd3+ fibers possessed a fine, irregularly porous fibrous morphology with an average diameter of 378 nm. The florescence of the sample (1064 nm) could be excited over a wide wavelength range in the NIR region. During the release process of IBU in simulated body fluid (SBF), along with the dissolving of the drug, the solvent entered into the pores, and the emission intensity of the YAG:Nd3+ fibers at 1064 nm decreased gradually, owing to a quenching effect of the hydroxy groups, thus provided an approach to track and monitor drug release. In addition, cytotoxicity investigations revealed that these YAG:Nd3+ fibers were biocompatible with human cells. Consequently, the porous YAG:Nd3+ fibers are a promising material for applications as advanced drug carriers.
ChemInform Abstract: Synthesis, Crystal Structure and Chemical Bonding of the Zintl Phase Rb7NaSi8.
Authors: Goebel Thorsten , Prots Yurii , Ormeci Alim , Pecher Oliver , Haarmann Frank
Published: January 2012

The title phase is synthesized from stoichiometric amounts of Na4Si4 and Rb4Si4 (500 °C, 7 d) and characterized by single crystal and powder XRD, MAS NMR spectroscopy, magnetic measurements, and quantum chemical calculations (all electron, full‐potential local orbital minimum basis method).
ChemInform Abstract: A New Emission Band of Eu2+ and Its Efficient Energy Transfer to Mn2+ in Sr2Mg3P4O15:Mn2+, Eu2+.
Authors: Yu Jinying , Hao Zhendong , Zhang Xia , Luo Yongshi , Zhang Jiahua
Published: January 2012

Eu2+‐doped and Eu2+/Mn2+ co‐doped Sr2Mg3P4O15 exhibit a new emission band centered at 399 nm in addition to the well known band at 448 nm.
ChemInform Abstract: [(Ph)3PBr][Br7], [(Bz)(Ph)3P]2[Br8], [(n‐Bu)3MeN]2 [Br20], [C4MPyr]2[Br20], and [(Ph)3PCl]2[Cl2I14]: Extending the Horizon of Polyhalides via Synthesis in Ionic Liquids.
Authors: Wolff Michael , Okrut Alexander , Feldmann Claus
Published: January 2012

The polyhalides (II), (III), and (V) are prepared from dibromine in eutectic, equimolar mixtures of the ionic liquids (dpyr)Br and (bpyr)CF3SO3.
ChemInform Abstract: Methanesulfonates of High‐Valent Metals: Syntheses and Structural Features of MoO2(CH3SO3)2, UO2(CH3SO3)2, ReO3(CH3SO3), VO(CH3SO3)2, and V2O3(CH3SO3)4 and Their Thermal Decomposition under N2 and O2 Atmosphere.
Authors: Betke Ulf , Neuschulz Kai , Wickleder Mathias S.
Published: January 2012

The title compounds are the first examples of solvent‐free oxide methanesulfonates of Mo, U, Re, and V.
ChemInform Abstract: Isolation of a Stable Lacunary Dawson‐Type Polyoxomolybdate Cluster.
Authors: Hashikawa Akihiro , Fujimoto Makiko , Hayashi Yoshihito , Miyasaka Hitoshi
Published: January 2012

The hexa‐lacunary Dawson type polyoxomolybdate (Bu4N)2 [MoV4MoVI10O38 (OAc)6] (I) is synthesized from (Bu4N)2[Mo6O19] dissolved in MeCN and a mixture of acetic acid and acetic anhydrid solution in the presence of Bu3SnH (N2, reflux, 12 h, 45% yield).
ChemInform Abstract: Metal‐Centered Deltahedral Zintl Ions: Synthesis of [Ni@Sn9]4‐ by Direct Extraction from Intermetallic Precursors and of the Vertex‐Fused Dimer [{Ni@Sn8(μ‐Ge)1/2}2]4‐.
Authors: Gillett‐Kunnath Miriam M. , Paik Joseph I. , Jensen Sara M. , Taylor Jacob D. , Sevov Slavi C.
Published: January 2012

The endohedral cluster [Ni@Sn9]4‐ is extracted in en from the new precursors (I), (IV), and (VII), which are obtained from mixtures of the elements (Nb containers, 950 °C, 2 d).