bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Photophysical, and Electroluminescent Device Properties of Zn(II)‐Chelated Complexes Based on Functionalized Benzothiazole Derivatives
Authors: Roh Soo‐Gyun , Kim Yong‐Hee , Seo Kang Deuk , Lee Dong Hyun , Kim Hwan Kyu , Park Young‐Il , Park Jong‐Wook , Lee Ji‐Hoon 
Published: April 2009

AbstractNew Zn(II)‐chelated complexes based on benzothiazole derivatives, including substituted functional groups such as methyl (MeZn), methoxy (MeOZn), or fluorenyl unit (FuZn), are investigated to produce white‐light emission. 2‐(2‐Hydroxyphenyl)benzothiazole derivatives in toluene and DMSO exhibit excited‐state intramolecular proton transfer (ESIPT), leading to a large Stokes shift of the fluorescence emission. However, in methanol they exhibit no ESIPT due to the intermolecular hydrogen bonding between the 2‐(2‐hydroxyphenyl)benzothiazole derivative and methanol. Their Zn(II)‐chelated complexes exhibit the absorption band red‐shifted at 500 nm in nonpolar solvent and the absorption band blue‐shifted at about 420 nm in protic solvent. In multilayer electroluminescent devices, methyl‐substituted Zn(II)‐chelated complex (MeZn) exhibits excellent power efficiency and fluorene‐substituted Zn(II)‐chelated complex (FuZn) has a high luminance efficiency (1 cd m−2 at 3.5 V, 10 400 cd m−2 at 14 V). The EL spectra of Zn(II)‐chelated complexes based on benzothiazole derivatives exhibit broad emission bands. In addition, their electron‐transport property for red–green–blue (RGB) organic light‐emitting diodes (OLEDs) is systematically studied, in comparison with that of Alq3. The results demonstrate the promising potential of MeZn as an electron‐transporting layer (ETL) material in preference to Alq3, which is widely used as an ETL material.
Silicon‐Doped LiFePO4 Single Crystals: Growth, Conductivity Behavior, and Diffusivity
Authors: Amin Ruhul , Lin Chengtian , Peng Jubo , Weichert Katja , Acartürk Tolga , Starke Ulrich , Maier Joachim 
Published: April 2009

AbstractSingle crystals of silicon doped LiFePO4 with a silicon content of 1% are grown successfully by the floating zone technique and characterized by single‐crystal and powder X‐ray diffraction, secondary ion mass spectroscopy, and chemical analysis. Electron paramagnetic resonance demonstrates the presence of only Fe2+; no traces of Fe3+ are found. Impedance spectroscopy as well as step‐function polarization/depolarization (DC) measurements are carried out using the cells Ti/LiFe(Si)PO4/Ti and LiAl/LiI/LiFe(Si)PO4/LiI/LiAl. The electronic and ionic conductivities as well as the Li‐diffusivity of the sample in the major crystallographic directions ([h00], [0k0], and [00l]) are determined. Within experimental error the transport properties along the b‐ and c‐axes are found to be the same but differ significantly from the a‐axis, which exhibits lower values. Compared to undoped LiFePO4, Si‐doping leads to an increase of the ionic conductivity while the electronic conductivity decreases, which is in agreement with a donor effect. The activation energies of conductivities and diffusivities are interpreted in terms of defect chemistry and relevant Brouwer diagrams are given.
New Generation of Multifunctional Nanoparticles for Cancer Imaging and Therapy
Authors: Park Kyeongsoon , Lee Seulki , Kang Eunah , Kim Kwangmeyung , Choi Kuiwon , Kwon Ick Chan 
Published: April 2009

AbstractAdvances in nanotechnology have contributed to the development of novel nanoparticles that enable the tumor‐specific delivery of imaging probes and therapeutic agents in cancer imaging and therapy. Nanobiotechnology combines nanotechnology with molecular imaging, which has led to the generation of new multifunctional nanoparticles for cancer imaging and therapy. Multifunctional nanoparticles hold great promise for the future of cancer treatment because they can detect the early onset of cancer in each individual patient and deliver suitable therapeutic agents to enhance therapeutic efficacy. The combination of tumor‐targeted imaging and therapy in an all‐in‐one system provides a useful multimodal approach in the battle against cancer. Novel multifunctional nanoparticles thus offer a new avenue in the application of personalized medicine in the near future. Herein, new trends and the significance of novel multifunctional nanoparticles in cancer imaging and therapy are reviewed.magnified image
Novel Brush Polymers with Phosphorylcholine Bristle Ends: Synthesis, Structure, Properties, and Biocompatibility
Authors: Kim Gahee , Park Samdae , Jung Jungwoon , Heo Kyuyoung , Yoon Jinhwan , Kim Heesoo , Kim Ik Jung , Kim Jung Ran , Lee Jong Im , Ree Moonhor 
Published: April 2009

AbstractNew brush polymers with various numbers of bristle ends incorporating phosphorylcholine (PC) moieties are synthesized. The polymers are thermally stable up to 175 °C and form good‐quality films with conventional spin‐, roll‐, and dip‐coating, and subsequent drying processes. Interestingly, all these brush polymers, as a PC‐containing polymer, demonstrate a stable molecular multi‐bilayer structure in thin films that arise due to the efficient self‐assembly of the bristles for temperatures <55 °C and PC‐rich surfaces, and therefore successfully mimic natural cell‐membrane surfaces. These brush‐polymer films exhibit excellent water wettability and water sorption whilst retaining the remarkable molecular multi‐bilayer structure, and thus have hydrophilic surfaces. These novel multi‐bilayer structured films repel fibrinogen molecules and platelets from their surfaces but also have bactericidal effects on bacteria. Moreover, the brush‐polymer films are found to provide comfortable surface environments for the successful anchoring and growth of HEp‐2 cells, and to exhibit excellent biocompatibility in mice. These newly developed brush polymers are suitable for use in biomedical applications including medical devices and biosensors that require biocompatibility and the reduced possibility of post‐operative infection.
Ionic Iridium(III) Complexes with Bulky Side Groups for Use in Light Emitting Cells: Reduction of Concentration Quenching
Authors: Rothe Carsten , Chiang Chien‐Jung , Jankus Vygintas , Abdullah Khalid , Zeng Xianshun , Jitchati Rukkiat , Batsanov Andrei S. , Bryce Martin R. , Monkman Andrew P. 
Published: April 2009

AbstractHere, the photophysics and performance of single‐layer light emitting cells (LECs) based on a series of ionic cyclometalated Ir(III) complexes of formulae $\left[ {{\rm Ir}\left( {{\rm ppy}} \right)_{\rm 2} \left( {{\rm bpy}} \right)} \right]^ + {\rm PF}_{\rm 6}^ -$ and $\left[ {{\rm Ir}\left( {{\rm ppy}} \right)_{\rm 2} \left( {{\rm phen}} \right)} \right]^ + {\rm PF}_{\rm 6}^ -$ where ppy, bpy, and phen are 2‐phenylpyridine, substituted bipyridine and substituted phenanthroline ligands, respectively, are reported. Substitution at the NˆN ligand has little effect on the emitting metal‐ligand to ligand charge‐transfer (MLLCT) states and functionalization at this site of the complex leads to only modest changes in emission color. For the more bulky complexes the increase in intermolecular separation leads to reduced exciton migration, which in turn, by suppressing concentration quenching, significantly increases the lifetime of the excited state. On the other hand, the larger intermolecular separation induced by bulky ligands reduces the charge carrier mobility of the materials, which means that higher bias fields are needed to drive the diodes. A brightness of ca. 1000 cd m−2 at 3 V is obtained for complex 5, which demonstrates a beneficial effect of bulky substituents.
Fabrication and Electrochemical Properties of Epitaxial Samarium‐Doped Ceria Films on SrTiO3‐Buffered MgO Substrates
Authors: Sanna Simone , Esposito Vincenzo , Pergolesi Daniele , Orsini Andrea , Tebano Antonello , Licoccia Silvia , Balestrino Giuseppe , Traversa Enrico 
Published: April 2009

AbstractThin films of samarium‐oxide‐doped (20 mol%) ceria (SDC) are grown by pulsed‐laser deposition (PLD) on (001) MgO single‐crystal substrates. SrTiO3 (STO) prepared by PLD is used as a buffer layer on the MgO substrates to enable epitaxial growth of the fluorite‐structured SDC film; the STO layer provides a proper crystalline match between SDC and MgO, resulting in highly crystalline, epitaxial SDC films grown in the (001) orientation. Film conductivity is evaluated by electrochemical impedance spectroscopy measurements, which are performed at various temperatures (400–775 °C) in a wide range of oxygen partial pressure (pO2) values (10−25−1 atm) in order to separate ionic and electronic conductivity contributions. At 700 °C, SDC/STO films on (100) MgO exhibit a dominant ionic conductivity of about 7 × 10−2 S cm−1, down to pO2 values of about 10−15 atm. The absence of grain boundaries make the SDC/STO/MgO heterostructures stable to oxidation‐reduction cycles at high temperatures, in contrast to that observed for the more disordered SDC/STO films, which degraded after hydrogen exposure.
Metal‐Free Click Polymerization: Synthesis and Photonic Properties of Poly(aroyltriazole)s
Authors: Qin Anjun , Tang Li , Lam Jacky W. Y. , Jim Cathy K. W. , Yu Yong , Zhao Hui , Sun Jingzhi , Tang Ben Zhong 
Published: April 2009

AbstractRegioselective 1,3‐dipolar polycycloadditions of tetraphenylethene (TPE)‐containing diazides 1–3 and bis(aroylacetylene) 4 are initiated by simple heating, affording poly(aroyltriazole)s (PATAs) PI–PIII with high molecular weights in high yields. The PATAs are completely soluble in common organic solvents and stable at temperatures up to 358 °C. Thanks to their TPE units, the polymers show aggregation‐induced emission and work as explosive sensors with high sensitivity. The PATAs are optically transparent in the whole visible spectral region. Their refractive indexes can be tuned to a great extent (Δn ≈ 0.08) by simply changing their alkyl spacer lengths. The modified Abbé numbers of the PATAs are very high (up to 273), indicative of very low optical dispersions in the telecommunication‐important wavelength region. UV irradiation through a photomask quenches the light emissions of the polymers, enabling the generation of two‐dimensional fluorescent images without development. The polymers can be readily photo‐crosslinked, yielding three‐dimensional patterns with high resolutions.
Molecular Self‐Assembled Monolayers and Multilayers for Organic and Unconventional Inorganic Thin‐Film Transistor Applications
Authors: DiBenedetto Sara A. , Facchetti Antonio , Ratner Mark A. , Marks Tobin J. 
Published: April 2009

AbstractPrincipal goals in organic thin‐film transistor (OTFT) gate dielectric research include achieving: (i) low gate leakage currents and good chemical/thermal stability, (ii) minimized interface trap state densities to maximize charge transport efficiency, (iii) compatibility with both p‐ and n‐ channel organic semiconductors, (iv) enhanced capacitance to lower OTFT operating voltages, and (v) efficient fabrication via solution‐phase processing methods. In this Review, we focus on a prominent class of alternative gate dielectric materials: self‐assembled monolayers (SAMs) and multilayers (SAMTs) of organic molecules having good insulating properties and large capacitance values, requisite properties for addressing these challenges. We first describe the formation and properties of SAMs on various surfaces (metals and oxides), followed by a discussion of fundamental factors governing charge transport through SAMs. The last section focuses on the roles that SAMs and SAMTs play in OTFTs, such as surface treatments, gate dielectrics, and finally as the semiconductor layer in ultra‐thin OTFTs.
Bioinspired Design of Dynamic Materials
Authors: Mohammed Javeed Shaikh , Murphy William L. 
Published: April 2009

AbstractAn emerging approach for design of dynamic materials involves mimicking natural systems, which are adept at changing their structure and function in response to their environment. Biological systems possess a diverse range of dynamic mechanisms, including competitive ligand–protein binding, enzyme‐catalyzed remodeling, and allosteric protein conformational changes. These dynamic mechanisms are now being exploited by materials scientists and engineers to design “bioinspired” synthetic materials that undergo responsive assembly and disassembly as well as dynamic volume and shape changes. The purpose of this review is to describe recent progress in design and development of bioinspired dynamic materials, with a particular emphasis on hydrogel networks. We specifically focus on emerging approaches that use biological phenomena as an inspiration for design of materials.
Evolutionary adaptation to high altitude: A view from in utero
Authors: Julian Colleen Glyde , Wilson Megan J. , Moore Lorna G. 
Published: April 2009

AbstractA primary focus within biological anthropology has been to elucidate the processes of evolutionary adaptation. Frisancho helped to move anthropology towards more mechanistic explanations of human adaptation by drawing attention to the importance of the functional relevance of human variation. Using the natural laboratory of high altitude, he and others asked whether the unique physiology of indigenous high‐altitude residents was the result of acclimatization, developmental plasticity, and/or genetic adaptation in response to the high‐altitude environment. We approach the question of human adaptation to high altitude from a somewhat unique vantage point; namely, by examining physiological characteristics—pregnancy and pregnancy outcome—which are closely associated with reproductive fitness. Here we review the potent example of high‐altitude native population's resistance to hypoxia‐associated reductions in birth weight, which is often associated with higher infant morbidity and mortality at high altitude. With the exception of two recent publications, these comparative birth weight studies have utilized surnames, self‐identification, and/or linguistic characteristics to assess ancestry, and none have linked ‘advantageous’ phenotypes to specific genetic variations. Recent advancements in genetic and statistical tools have enabled us to assess individual ancestry with higher resolution, identify the genetic basis of complex phenotypes and to infer the effect of natural selection on specific gene regions. Using these technologies our studies are now directed to determine the genetic variations that underlie the mechanisms by which high‐altitude ancestry protects fetal growth and, in turn, to further our understanding of evolutionary processes involved in human adaptation to high altitude. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Pooled energy budget and human life history
Authors: Reiches Meredith W. , Ellison Peter T. , Lipson Susan F. , Sharrock Katherine C. , Gardiner Eliza , Duncan Laura G. 
Published: April 2009

AbstractHuman life history contains a series of paradoxes not easily explained by classical life history theory. Although overall reproductive output is higher than in related primates, juvenile growth is slower and age‐specific reproductive rates decline faster with age. A simple energetic model would predict that growth and reproductive rates should be positively correlated and that reproductive effort should not decelerate with age. The pattern of negative correlations in humans suggest the presence of trade‐offs among peak reproductive rate, childhood growth, and reproductive rate at older ages. To address this puzzle, we propose a synthesis of reproductive ecology and behavioral ecology focused on intra‐ and inter‐somatic energy transfers. This integration includes three concepts: the mother as final common pathway through which energy must pass to result in offspring; a distinction between direct and indirect reproductive effort, proposing the latter as a novel net energy allocation category relative to growth and direct reproductive effort; and a pooled energy budget representing the energetic contributions and withdrawals of all members of a breeding community. Individuals at all reproductive life stages are considered in light of their contributions to the pooled energy budget. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Cultural versus reproductive success: Why does economic development bring new tradeoffs?
Authors: Newson Lesley 
Published: April 2009

AbstractAchievements that attract social rewards in developed countries, such as educational qualifications, a prestigious career, and the ability to acquire prestige goods, interfere with a woman's ability to achieve reproductive success. This tradeoff between cultural and reproductive success may have developed because economic development creates an evolutionarily novel social environment. In the social environment of developed countries, a far smaller proportion of social exchange is between kin than in the small‐scale communities in which the human brain and behavior evolved. Evidence suggests that social interaction between non‐kin is less likely to encourage behavior that enhances inclusive fitness. A model of the cultural change that is likely to result from this change in social influence suggests that beliefs and values will become increasingly less consistent with the pursuit of fitness (Newson et al. [2007]: Evol Hum Behav 28: 199–210). Responses to the World Value Survey, which has been carried out in over 70 countries, confirm a number of the predictions of this model. In countries where fertility began to decline more recently, people appear to perceive the costs of having children to be lower relative to the cost of childlessness and the benefits of being a parent. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Seasonal and circadian variation in salivary testosterone in rural Bolivian men
Authors: Vitzthum Virginia J. , Worthman Carol M. , Beall Cynthia M. , Thornburg Jonathan , Vargas Enrique , Villena Mercedes , Soria Rudy , Caceres Esperanza , Spielvogel Hilde 
Published: April 2009

AbstractTestosterone (T) plays a key role in the increase and maintenance of muscle mass and bone density in adult men. Life history theory predicts that environmental stress may prompt a reallocation of such investments to those functions critical to survival. We tested this hypothesis in two studies of rural Bolivian adult men by comparing free T levels and circadian rhythms during late winter, which is especially severe, to those in less arduous seasons. For each pair of salivary TAM/TPM samples (collected in a ∼ 12‐h period), circadian rhythm was considered classic (CCLASSIC) if TAM > 110%TPM, reverse (CREVERSE) if TPM > 110%TAM, and flat (CFLAT) otherwise. We tested the hypotheses that mean TAM > mean TPM and that mean TLW < mean TOTHER (LW = late winter, OTHER = other seasons). In Study A, of 115 TPM–TAM pairs, 51% = CCLASSIC, 39% = CREVERSE, 10% = CFLAT; in Study B, of 184 TAM–TPM pairs, 55% = CCLASSIC, 33% = CREVERSE, 12% = CFLAT. Based on fitting linear mixed models, in both studies TOTHER‐AM > TOTHER‐PM (A: P = 0.035, B: P = 0.0005) and TOTHER‐AM > TLW‐AM (A: P = 0.054, B: P = 0.007); TPM did not vary seasonally, and T diurnality was not significant during late winter. T diurnality varied substantially between days within an individual, between individuals and between seasons, but neither T levels nor diurnality varied with age. These patterns may reflect the seasonally varying but unscheduled, life‐long, strenuous physical labor that typifies many non‐industrialized economies. These results also suggest that single morning samples may substantially underestimate peak circulating T for an individual and, most importantly, that exogenous signals may moderate diurnality and the trajectory of age‐related change in the male gonadal axis. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Gender‐specificCOMTVal158Met polymorphism association in Spanish schizophrenic patients
Authors: Hoenicka Janet , Garrido Elena , Martínez Isabel , Ponce Guillermo , Aragüés María , Rodríguez‐Jiménez Roberto , España‐Serrano Laura , Alvira‐Botero Ximena , Santos José Luis , Rubio Gabriel , Jiménez‐Arriero Miguel Ángel , Palomo Tomás ,   PARG
Published: April 2009

AbstractThe functional Val158Met polymorphism (rs4680) located at the gene that codes for the catechol‐O‐methyltransferase (COMT) has been extensively investigated in schizophrenia although current data are still controversial. Since COMT activity is sexually dimorphic, we carried out two independent studies in homogeneous samples of male and female Spanish schizophrenic patients. In males, we found an association between the homozygous Val genotype and the disorder, which resembled a recessive model (P = 0.022; odds ratio [OR] = 1.67). This Val homozygotes overrepresentation is produced at the expense of the heterozygous individuals decrease, whilst the Met homozygotes showed no differences when compared controls and patients. As a consequence, the heterozygous genotype in this sample had a protective effect (P = 0.03; OR = 0.65) and a strong deviation from Hardy–Weinberg equilibrium in male cases was observed (P = 0.006). In addition, a 2‐SNP haplotype analysis (rs4818‐Val158Met) confirmed there is an overrepresentation of the different homozygous Val genotypes in the male schizophrenic sample. Regarding females, we did not find any statistically significant association betweenCOMTSNP and schizophrenia. In the light of this we suggest that the Val158Met SNP is involved in risk and protective genotypes for the vulnerability to schizophrenia in Spanish male population. © 2009 Wiley‐Liss, Inc.
Identification of neuroglycan C and interacting partners as potential susceptibility genes for schizophrenia in a Southern Chinese population
Authors: So Hon‐Cheong , Fong Pui Y. , Chen Ronald Y.L. , Hui Tomy C.K. , Ng Mandy Y.M. , Cherny Stacey S. , Mak William W.M. , Cheung Eric F.C. , Chan Raymond C.K. , Chen Eric Y.H. , Li Tao , Sham Pak C. 
Published: April 2009

AbstractChromosome 3p was reported by previous studies as one of the regions showing strong evidence of linkage with schizophrenia. We performed a fine‐mapping association study of a 6‐Mb high‐LD and gene‐rich region on 3p in a Southern Chinese sample of 489 schizophrenia patients and 519 controls to search for susceptibility genes. In the initial screen, 4 SNPs out of the 144 tag SNPs genotyped were nominally significant (P < 0.05). One of the most significant SNPs (rs3732530, P = 0.0048) was a non‐synonymous SNP in the neuroglycan C (NGC, also known as CSPG5) gene, which belongs to the neuregulin family. The gene prioritization program Endeavor ranked NGC 8th out of the 129 genes in the 6‐Mb region and the highest among the genes within the same LD block. Further genotyping of NGC revealed 3 more SNPs to be nominally associated with schizophrenia. Three other genes (NRG1, ErbB3, ErbB4) involved in the neuregulin pathways were subsequently genotyped. Interaction analysis by multifactor dimensionality reduction (MDR) revealed a significant two‐SNP interaction between NGC and NRG1 (P = 0.015) and three‐SNP interactions between NRG1 and ErbB4 (P = 0.009). The gene NGC is exclusively expressed in the brain. It is implicated in neurodevelopment in rats and was previously shown to promote neurite outgrowth. Methamphetamine, a drug that may induce psychotic symptoms, was reported to alter the expression of NGC. Taken together, these results suggest that NGC may be a novel candidate gene, and neuregulin signaling pathways may play an important role in schizophrenia. © 2009 Wiley‐Liss, Inc.