bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Functionalization of 3D Matrices Via Multiphoton Grafting and Subsequent Click Chemistry
Authors: Ovsianikov Aleksandr , Li Zhiquan , Torgersen Jan , Stampfl Jürgen , Liska Robert 
Published: May 2012

AbstractGrafting is a popular approach for adjusting the properties and functionalization of various surfaces. Conventional photoinduced grafting has been utilized on flat surfaces, porous monoliths, and hydrogels. By masking or illuminating only a portion of the sample, a certain degree of spatial and temporal control is possible, but the ability to use grafting to pattern in 3D is limited. Here, the laser‐induced photolysis of an aromatic azide compound is employed for true 3D photografting within a poly(ethylene glycol) (PEG)‐based matrix. Since the multiphoton interaction occurs only in a confined area within the laser focal spot, the localized immobilization of a selected molecule with high spatial resolution in 3D is possible. In contrast to the widely utilized chain‐growth polymerization‐based grafting, the approach is characterized by a single‐molecule insertion mechanism. Successful binding of the fluorophore is confirmed by laser scanning microscopy. To test for the presence of latent azides and to determine the suitability for additional postmodification with arbitrary functional groups, the sample is further subjected to copper‐catalyzed alkyne click‐reaction conditions. The described 3D photografting method is simple, highly efficient, and universal. The presented results demonstrate the great potential of multiphoton‐induced grafting for 3D site‐specific functionalization.
Sodium‐Ion Batteries
Authors: Slater Michael D. , Kim Donghan , Lee Eungje , Johnson Christopher S. 
Published: May 2012

AbstractThe status of ambient temperature sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large‐scale grid storage applications due to the abundance and very low cost of sodium‐containing precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compounds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calculations of Na‐ion battery energy density indicate that 210 Wh kg−1 in gravimetric energy is possible for Na‐ion batteries compared to existing Li‐ion technology if a cathode capacity of 200 mAh g−1 and a 500 mAh g−1 anode can be discovered with an average cell potential of 3.3 V.
Hybrid Nanoparticles for Detection and Treatment of Cancer
Authors: Sailor Michael J. , Park Ji‐Ho 
Published: May 2012

AbstractThere is currently considerable effort to incorporate both diagnostic and therapeutic functions into a single nanoscale system for the more effective treatment of cancer. Nanoparticles have great potential to achieve such dual functions, particularly if more than one type of nanostructure can be incorporated in a nanoassembly, referred to in this review as a hybrid nanoparticle. Here we review recent developments in the synthesis and evaluation of such hybrid nanoparticles based on two design strategies (barge vs. tanker), in which liposomal, micellar, porous silica, polymeric, viral, noble metal, and nanotube systems are incorporated either within (barge) or at the surface of (tanker) a nanoparticle. We highlight the design factors that should be considered to obtain effective nanodevices for cancer detection and treatment.
Influence of Phonon Scattering on Exciton and Charge Diffusion in Polymer‐Fullerene Solar Cells
Authors: Presselt Martin , Herrmann Felix , Hoppe Harald , Shokhovets Sviatoslav , Runge Erich , Gobsch Gerhard 
Published: May 2012

AbstractThermally activated transport and phonon scattering in P3HT:PCBM (poly(3‐hexylthiophene‐2,5‐diyl):[6,6]‐phenylC61‐butyric acid methyl ester) bulk heterojunction (BHJ) organic solar cells is studied via temperature‐dependent external‐quantum‐efficiency (EQE) spectroscopy. The hopping barriers for combined exciton and charge transport are balanced for the individual blended materials in a sample, which possesses a blending ratio and a morphology that give rise to a maximal power‐conversion efficiency. Increasing the PCBM weight fraction leads to a reduction of exciton hopping barriers in PCBM, while for P3HT exciton hopping barriers remain constant. This reduction of PCBM exciton hopping barriers is attributed to a higher PCBM crystallinity in the PCBM‐rich solar cell as compared to the BHJ with the optimized blending ratio. The morphology‐dependent difference in exciton hopping activation energies between P3HT and PCBM is attributed to a higher impact of phonon scattering in P3HT than in PCBM, as concluded from the much stronger decrease of P3HT‐related temperature‐dependent external quantum efficiencies above room temperature in the PCBM‐rich BHJ solar cell. All EQE data of P3HT:PCBM‐based BHJ solar cells is modeled consistently over a broad temperature range by a simple analytical expression involving temperature activation and phonon scattering, without the need to distinguish two separate hopping regimes.
Ionomigration of Neutral Phases in Ionic Conductors
Authors: Chen I.‐Wei , Kim Seung‐Wan , Li Ju , Kang Suk‐Joong L. , Huang Fuqiang 
Published: May 2012

AbstractWithout sensing any physical force, a neutral object in an ion conducting solid can move in a uniform electrochemical field by coupling a global ion wind with localized counterion diffusion at the interface. This happens to pores and gas bubbles at 840 °C in a fast O2− conductor, yttria‐stabilized zirconia (YSZ), despite having cations that are essentially frozen with lattice diffusivities 1012 times slower than the O2− diffusivity. Through‐thickness migration and massive electro‐sintering in thin YSZ ceramics are observed at voltages similar to those in YSZ fuel cells and electrolysis cells. This effect should apply to any electrochemically‐loaded multiphase ionic conducting solid, with or without an electric field, and can lead to electrolyte sintering, phase accumulation and electrode debonding, resulting in unexpected benefit or damage in electrochemical devices. As the velocity obeys a pseudo Stokes‐Einstein equation, inversely proportional to the object size, an especially enhanced size effect is expected in nanocomposites.
Thermodynamic Efficiency Limit of Molecular Donor‐Acceptor Solar Cells and its Application to Diindenoperylene/C60‐Based Planar Heterojunction Devices
Authors: Gruber Mark , Wagner Julia , Klein Konrad , Hörmann Ulrich , Opitz Andreas , Stutzmann Martin , Brütting Wolfgang 
Published: May 2012

AbstractIn organic photovoltaic (PV) cells, the well‐established donor‐acceptor (D/A) concept enabling photo‐induced charge transfer between two partners with suitable energy level alignment has proven extremely successful. Nevertheless, the introduction of such a heterojunction is accompanied with additional energy losses as compared to an inorganic homojunction cell, owing to the presence of a charge‐transfer (CT) state at the D/A interface. Based on the principle of detailed balance, a modified Shockley‐Queisser theory is developed including the essential effects of interfacial CT states, that allows for a quantitative assessment of the thermodynamic efficiency limits of molecular D/A solar cells. Key parameters, apart from the optical gap of the absorber material, entering the model are the energy (ECT) and relative absorption strength (αCT) of the CT state. It is demonstrated how the open‐circuit voltage (VOC) and thus the power conversion efficiency are affected by different parameter values. Furthermore, it is shown that temperature dependent device characteristics can serve to determine the CT energy, and thus the upper limit of VOC for a given D/A combination, as well as to quantify non‐radiative recombination losses. The model is applied to diindenoperylene (DIP)‐based photovoltaic devices, with open‐circuit voltages between 0.9 and 1.4 V, depending on the partner, that have recently been reported.
Chronic myelomonocytic leukemia: 2012 update on diagnosis, risk stratification, and management
Authors: Parikh Sameer A. , Tefferi* Ayalew 
Published: May 2012

AbstractDisease Overview: Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder that is classified as a myelodysplastic/myeloproliferative neoplasm by the 2008 World Health Organization classification of hematopoietic tumors. It is characterized by absolute monocytosis (>1 × 109 L−1) in the peripheral blood that persists for at least 3 months. Patients may present with symptoms related to cytopenias and/or an underlying hypercatabolic state with drenching night sweats, splenomegaly, and weight loss.Diagnosis: The diagnosis of CMML rests on a combination of morphologic, histopathologic, and chromosomal abnormalities in the bone marrow, after careful exclusion of other conditions (both malignant and nonmalignant) that can cause monocytosis. Numerous molecular abnormalities have been recently recognized in patients with CMML—unfortunately, no single pathognomonic finding specific to CMML has been identified thus far.Risk stratification: The International Prognostic Scoring System for myelodysplastic syndrome (MDS) cannot be used to risk stratify patients with CMML because this model excluded patients with a leukocyte count >12 × 109 L−1. Other risk stratification models such as the MD Anderson prognostic score and Dusseldorf score have been published. In the only model that took karyotype into account, bone marrow blasts ≥ 10%, leukocyte count ≥ 13 × 109 L−1, hemoglobin < 10 g/dL, platelet count < 100 × 109 L−1, and presence of trisomy 8, abnormalities of chromosome 7, or complex karyotype were found to be independent predictors of adverse survival.Risk‐adapted therapy: The Food and Drug Administration has approved azacitidine and decitabine for the treatment of patients with CMML based on two pivotal trials in MDS. Novel classes of agents including immunomodulatory drugs, nucleoside analogs, and small‐molecule tyrosine kinase inhibitors are being investigated in the treatment of CMML. With the advent of reduced intensity conditioning, an allogeneic stem cell transplant has also become a viable option for a subset of patients. Am. J. Hematol. 87:610–619, 2012. © 2012 Wiley Periodicals, Inc.
Beckwith–Wiedemann syndrome in sibs discordant for IC2 methylation
Authors: Niederhoffer Karen Y. , Peñaherrera Maria , Pugash Denise , Rupps Rosemarie , Arbour Laura , Tessier Francine , Choufani Sanaa , Zhao Chunhua , Manokhina Irina , Shuman Cheryl , Robinson Wendy P. , Weksberg Rosanna , Boerkoel Cornelius F. 
Published: May 2012

AbstractGenetically heterogeneous imprinting disorders include Beckwith–Wiedemann syndrome (BWS) and multiple maternal hypomethylation syndrome (MMHS). Using DNA sequencing, quantitative PCR, SNuPE, pyrosequencing, and hybridization to the Illumina GoldenGate Methylation Cancer Panel 1 array, we characterized the genomic DNA of two brothers with BWS who were discordant for loss of methylation at several differentially methylated regions (DMR), including imprinting center 2 (IC2) on chromosome band 11p15.5, which is often hypomethylated in BWS. In keeping with MMHS, the elder child had hypomethylation of SGCE and PLAGL1 as well as of IC2, whereas the younger brother demonstrated no loss of methylation at these DMRs. Although this discordance is consistent with the observation that 15–20% of individuals with BWS do not have detectable genetic or epigenetic alterations of 11p15.5, this is the first report of familial recurrence of BWS with discordance for chromosomal 11p15.5 alterations. We hypothesize that this apparent discordance arises either from mosaicism precluding identification of IC2 hypomethylation in blood or buccal mucosa DNA of the younger child, or from hypomethylation at a site not interrogated by our molecular studies. © 2012 Wiley Periodicals, Inc.
Interpreting food processing through dietary mechanical properties: A Lemur catta case study
Authors: Yamashita Nayuta , Cuozzo Frank P. , Sauther Michelle L. 
Published: May 2012

AbstractKnowledge of dietary mechanical properties can be informative about physical consequences to consumers during ingestion and mastication. In this article, we examine how Tamarindus indica fruits can affect dental morphology in a population of ring‐tailed lemurs (Lemur catta) at Beza Mahafaly special reserve in southwestern Madagascar. Ring‐tailed lemurs in tamarind dominated gallery forests exhibit extreme wear and tooth loss on their postcanine dentition that has been related to processing T. indica fruits. We measured and compared mechanical properties of individual food parts in the diet of ring‐tailed lemurs in different seasons in 1999–2000, 2008, and 2010. Fracture toughness, hardness, and modulus of foods were measured with a portable mechanical tester. The ripe fruits of T. indica are indeed the toughest and hardest foods ingested by the lemurs. In addition, they are among the largest foods consumed, require high numbers of ingestive bites to process, and are the most frequently eaten by volume. During controlled cutting tests of the ripe fruit shell, multiple runaway side cracks form alongside the cut. Similarly, the lemurs repeatedly bite the ripe shell during feeding and thereby introduce multiple cracks that eventually fragment the shell. Studies of enamel microstructure (e.g., Lucas et al.: BioEssays 30 (2008) 374–385; Campbell et al., 2011) advance the idea that the thin enamel of ring‐tailed lemur teeth is susceptible to substantial micro‐cracking that rapidly erodes the teeth. We conclude that micro‐cracking from repeated loads, in combination with the mechanical and physical properties of the fruit, is primarily responsible for the observed dental damage. Am J Phys Anthropol 148:205–214, 2012. © 2012 Wiley Periodicals, Inc.
The impact of dental impairment on ring‐tailed lemur food processing performance
Authors: Millette James B. , Sauther Michelle L. , Cuozzo Frank P. , Ness Jenifer L. 
Published: May 2012

AbstractDuring mastication, foods are reduced into particles suitable for swallowing and digestion. Smaller particles possess a greater surface area per unit of volume on which digestive enzymes and bacteria may work than relatively larger particles, and are thus more readily digested. As dental morphology facilitates the breakdown of diets with specific mechanical properties, extensive dental wear and/or tooth loss may impede an individual's ability to break down and exploit foods. We present data demonstrating a relationship between dental impairment and particle size in 43 fecal samples from 33 ring‐tailed lemurs at the Beza Mahafaly Special Reserve (BMSR), Madagascar. All fecal samples were sifted through three sieves of decreasing size (11.2 mm, 4.75 mm, and 1.0 mm). The resulting fraction in each sieve was then weighed and assessed in relation to individual dental impairment status. With increasing wear, the percentage of each sample within the 1.0 mm sieve decreases, whereas that in the 11.2 mm sieve increases with increasing postcanine wear, although these effects are not present when limited to individuals without tooth loss. Individuals with tooth loss also demonstrate larger proportions of fecal material 1.0–4.75 mm in size. Dental impairment results in larger food particles and potentially less efficient utilization of foods. When fecal material was examined by leaf vs. fruit content, individuals with tooth loss demonstrated reduced proportions of fruit in the 1.0 mm and 11.2 mm sieves. These data suggest individuals with tooth loss consume less fruit than those without loss, potentially reflecting a reduced ability to process tamarind fruit, a key fallback resource at BMSR. Am J Phys Anthropol 148:238–248, 2012. © 2012 Wiley Periodicals, Inc.
Dental topography indicates ecological contraction of lemur communities
Authors: Godfrey Laurie R. , Winchester Julia M. , King Stephen J. , Boyer Doug M. , Jernvall Jukka 
Published: May 2012

AbstractUnderstanding the paleoecology of extinct subfossil lemurs requires reconstruction of dietary preferences. Tooth morphology is strongly correlated with diet in living primates and is appropriate for inferring dietary ecology. Recently, dental topographic analysis has shown great promise in reconstructing diet from molar tooth form. Compared with traditionally used shearing metrics, dental topography is better suited for the extraordinary diversity of tooth form among subfossil lemurs and has been shown to be less sensitive to phylogenetic sources of shape variation. Specifically, we computed orientation patch counts rotated (OPCR) and Dirichlet normal energy (DNE) of molar teeth belonging to 14 species of subfossil lemurs and compared these values to those of an extant lemur sample. The two metrics succeeded in separating species in a manner that provides insights into both food processing and diet. We used them to examine the changes in lemur community ecology in Southern and Southwestern Madagascar that accompanied the extinction of giant lemurs. We show that the poverty of Madagascar's frugivore community is a long‐standing phenomenon and that extinction of large‐bodied lemurs in the South and Southwest resulted not merely in a loss of guild elements but also, most likely, in changes in the ecology of extant lemurs. Am J Phys Anthropol 148:215–227, 2012. © 2012 Wiley Periodicals, Inc.
Linear enamel hypoplasia as an indicator of physiological stress in great apes: Reviewing the evidence in light of enamel growth variation
Authors: Guatelli‐Steinberg Debbie , Ferrell Rebecca J. , Spence Jennifer 
Published: May 2012

AbstractPhysiological stress, such as malnutrition or illness, can disrupt normal enamel growth, resulting in linear enamel hypoplasias (LEHs). Although ecological factors may contribute to LEH expression, other factors, such as surface abrasion and enamel growth variables, are also likely to be involved. Attention to these other factors is necessary before we can begin to understand what LEH might signify in terms of ecological sources of physiological stress in non‐human primates. This study focuses on assessing the contribution of these other factors to variation in LEH expression within and across great ape taxa. Here, we present LEH data from unabraded crown regions in samples of seven great ape species. We analyze these data with respect to lateral enamel formation time and the angles that striae of Retzius make with the enamel surface, as these variables are expected to affect variation in LEH expression. We find that although the duration of enamel formation is associated with sex differences in LEH expression, it is not clearly related to taxonomic variation in LEH expression, and does not explain the low frequency of LEH in mountain gorillas found in this and a previous study. Our data on striae of Retzius angles suggest that these influence LEH expression along the tooth crown and may contribute to the consistently high frequencies of LEH seen in Pongo in this and previous studies. We suggest that future work aimed at understanding species variation in these angles is crucial to evaluating taxonomic patterns of LEH expression in great apes. Am J Phys Anthropol 148:191–204, 2012. © 2012 Wiley Periodicals, Inc.
Variation of bone collagen amino acid δ13c values in archaeological humans and fauna with different dietary regimes: Developing frameworks of dietary discrimination
Authors: Honch Noah V. , McCullagh James S.O. , Hedges Robert E.M. 
Published: May 2012

AbstractWe present bone collagen amino acid (AA) δ13C values for a range of archaeological samples representing four “benchmark” human diet groups (high marine protein consumers, high freshwater protein consumers, terrestrial C3 consumers, and terrestrial C4 consumers), a human population with an “unknown” diet, and ruminants. The aim is to establish an interpretive palaeodietary framework for bone collagen AA δ13C values, and to assess the extent to which AA δ13C values can provide additional dietary information to bulk collagen stable isotope analysis. Results are analyzed to determine the ability of those AAs for which we have a complete set, to discriminate between the diet groups. We show that very strong statistical discrimination is obtained for all interdiet group comparisons. This is often obvious from suitably chosen bivariate plots using δ113C values that have been normalized to compensate for interdiet group differences in bulk δ13C values. Bi‐plots of non‐normalized phenylalanine and valine δ13C values are useful for distinguishing aquatic diets (marine and freshwater) from terrestrial diets. Our interpretive framework uses multivariate statistics (e.g., discriminant analysis) to optimize the separation of the AA δ13C values of the “benchmark”’ diet groups, and is capable of accurately assigning external samples to their expected diet groups. With a growing body of AA δ13C values, this method is likely to enhance palaeodietary research by allowing the “unknown” diets of populations under investigation to be statistically defined relative to the well‐characterized or “known” diets of previously investigated populations. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.
Primate dental ecology: How teeth respond to the environment
Authors: Cuozzo Frank P. , Ungar Peter S. , Sauther Michelle L. 
Published: May 2012

AbstractTeeth are central for the study of ecology, as teeth are at the direct interface between an organism and its environment. Recent years have witnessed a rapid growth in the use of teeth to understand a broad range of topics in living and fossil primate biology. This in part reflects new techniques for assessing ways in which teeth respond to, and interact with, an organism's environment. Long‐term studies of wild primate populations that integrate dental analyses have also provided a new context for understanding primate interactions with their environments. These new techniques and long‐term field studies have allowed the development of a new perspective—dental ecology. We define dental ecology as the broad study of how teeth respond to, or interact with, the environment. This includes identifying patterns of dental pathology and tooth use–wear, as they reflect feeding ecology, behavior, and habitat variation, including areas impacted by anthropogenic disturbance, and how dental development can reflect environmental change and/or stress. The dental ecology approach, built on collaboration between dental experts and ecologists, holds the potential to provide an important theoretical and practical framework for inferring ecology and behavior of fossil forms, for assessing environmental change in living populations, and for understanding ways in which habitat impacts primate growth and development. This symposium issue brings together experts on dental morphology, growth and development, tooth wear and health, primate ecology, and paleontology, to explore the broad application of dental ecology to questions of how living and fossil primates interact with their environments. Am J Phys Anthropol 148:159–162, 2012. © 2012 Wiley Periodicals, Inc.