bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Common and Distinctive Mechanisms of Resistance to Different Anti-IGF-IR Agents in Ewing's Sarcoma
Authors: Garofalo Cecilia , Mancarella Caterina , Grilli Andrea , Manara Maria Cristina , Astolfi Annalisa , Marino Maria Teresa , Conte Alexia , Sigismund Sara , Carè Alessandra , Belfiore Antonino , Picci Piero , Scotlandi Katia
Published: July 2012

IGF system contributes significantly to many human malignancies. Targeting IGF-I receptor (IGF-IR) has been reported to be active against several tumors, but particular efficacy was observed only against a minority of Ewing's sarcoma patients. Identification of mechanisms of acquired resistance to anti-IGF-IR agents is mandatory to individualize their use in clinics and optimize cure costs. In this study, we compared gene expression profiles of cells made resistant with three different anti-IGF-IR drugs (human antibodies AVE1642, Figitumumab, or tyrosine kinase inhibitor NVP-AEW541) to highlight common and distinctive mechanisms of resistance. Among common mechanisms, we identified two molecular signatures that distinguish sensitive from resistant cells. Annotation analysis indicated some common altered pathways, such as insulin signaling, MAPK pathway, endocytosis, and modulation of some members of the interferon-induced transmembrane protein family. Among distinctive pathways/processes, resistance to human antibodies involves mainly genes regulating neural differentiation and angiogenesis, whereas resistance to NVP-AEW541 is mainly associated with alterations in genes concerning inflammation and antigen presentation. Evaluation of the common altered pathways indicated that resistant cells seem to maintain intact the IGF-IR internalization/degradation route of sensitive cells but constantly down-regulated its expression. In resistant cells, the loss of proliferative stimulus, normally sustained by IGF-I/IGF-IR autocrine loop in Ewing's sarcoma cells, is compensated by transcriptional up-regulation of IGF-II and insulin receptor-A; this signaling seems to favor the MAPK pathway over the v-akt murine thymoma viral oncogene homolog 1 pathway. Overall, complexity of IGF system requires analytical evaluation of its components to select those patients that may really benefit from this targeted therapy and support the idea of cotargeting IGF-IR and insulin receptor-A to increase the efficacy.
Cognitive Investigations: The Problems of Qualia and Style in the Contemporary Neuronovel
Authors: Gaedtke Andrew
Published: July 2012

Recent developments in cognitive science have overturned the restrictions of behaviorism and have once again made consciousness a legitimate object of scientific investigation. New brain scanning technologies have introduced the possibility of mapping the neural correlates of consciousness, thereby offering a full, materialist account of the mind. This article argues that an emergent subgenre of contemporary fiction has both formally integrated and critically assessed these discourses of the mind. The “neuronovels” of Ian McEwan, David Lodge, and others have specifically addressed “the explanatory gap” between the third-person accounts of neuroscience and the first-person perspective of conscious experience—a gap that some philosophers of mind regard as an irreducible obstacle to any complete, scientific explanation of consciousness. Novels such as McEwan's Enduring Love (1998) and Lodge's Thinks … (2002) transform this problem of qualia into a formal problem of narrative style. Finally, this article shows that such conceptual transactions between cognitive science and contemporary literature move in both directions. While recent fiction has integrated the discourses and problems posed by brain science, neuroscientists have drawn upon the narrative techniques of experimental literature in order to present their evolving theories of consciousness.
Toward a Modest Criticism: Ian McEwan's Saturday
Authors: Dancer Thom
Published: July 2012

This essay argues that a critique of epistemological immodesty is at the center of Ian McEwan's literary project. His fiction dramatizes the dangerous and tragic consequences of granting one's own interpretative frameworks a certainty and authority that they do not warrant. Enduring Love's Joe Rose, Atonements Briony Tallis, and Solars Michael Beard, for example, fail not because they rely on their fundamental beliefs about the world but because they do not see that those beliefs are just as contestable and uncertain as the views they reject. Their “immodesty” lies in the power and coercive force they see their views carrying. McEwan's work finds the forms of this immodesty not just in religious or political ideals but in science, criticism, and secularism, the latter perhaps the more concerning because they conceal their immodesty in the allegedly modest forms of “neutrality” and “objectivity.” Critics of McEwan who accuse his world of being politically conservative fail to account for the effects of this critique of immodesty, which calls into question the very definitions of “the literary” and “the political” that are deployed against him. The desire to insert McEwan's work into interpretative frameworks it explicitly rejects exemplifies precisely the kind of immodesty challenged in this work. Moving between readings of criticisms of Saturday and readings of the novel itself, the essay argues that McEwan's work promotes an ethos of modesty, challenging immodest conceptions of public life, politics, and criticism found in science, rationalism, and secularism that rely on and advance restrictive definitions of thinking, argument, and deliberation.
Prolonged Suspension: Don DeLillo, Ian McEwan, and the Literary Imagination After 9/11
Authors: Spahr Clemens
Published: July 2012

As closely as the issues of representation, ethics, and politics were connected in the immediate aftermath of 9/11, the scholarly debate over its literary representations soon shifted to questions of trauma and commemoration, a shift in emphasis that often displaced concerns with the political work that literature can do. The importance of post-9/11 literature, however, depends on its ability to rewrite itself in the coordinate system of geopolitical affairs. This essay reads Don DeLillo's Falling Man and Ian McEwan's Saturday as symptomatic of the ambivalent literary reaction to the political situation after the collapse of the Twin Towers. Tracing the relation between the literary imagination and the socioeconomic and geopolitical conditions for literary production after 9/11, the essay argues that while both novels do important cultural work in pondering the power and the limits of literature after 9/11, they are never fully able to come to terms with the issues of class, poverty, empire, and religion they constantly evoke. While Falling Man and Saturday ask important questions about the place of literature in a post-9/11 world, both novels ultimately fail to assign a meaningful political role to themselves because of their reluctance to imagine a future that is significantly different from the present.
Fact, Fiction, Fidelity in the Novels of Jonathan Safran Foer
Authors: Mandel Naomi
Published: July 2012

This essay examines the role of fact and the injunction of fidelity to it in fiction about violent historical events. Taking as its starting point Jonathan Safran Foer's 2002 novel, Everything Is Illuminated (set in the wake of the Holocaust), and his 2005 novel, Extremely Loud and Incredibly Close (set in New York City after the terror attacks of September 11, 2001), it examines the dictate that fiction about historical violence must perforce be true to the facts. This dictate aligns fidelity with ethics and sets as its stakes the dismaying implications of blurring the distinction between perpetrator and victim. Fidelity to the facts thus combines the juridical with the factual and renders fiction answerable to history. With recourse to Alain Badiou's concept of fidelity, the author argues for an approach to fidelity in fiction that attends to the truths that fidelity produces, not merely those that it reflects. Viewed thus, Foer's novels trace multiple trajectories of fidelity toward and away from history and offer useful guidelines for fiction as a site of ethical engagement with violence in the twenty-first century.
Allegories of the Contemporary
Authors: Hensley Nathan K.
Published: July 2012

This article suggests that by viewing world-historical situations recursively, we disclose links between apparently separate but structurally similar historical conjunctures and the cultural forms that mediate them. By examining three late-imperial texts—Robert Louis Stevenson's 1886 Strange Case of Dr. Jekyll and Mr. Hyde, Giorgio Agamben's Homo Sacer (1995, trans. 1998), and Jonathan Franzen's 2001 The Corrections—the article shows that works from the residual or “late” phases of two successive hegemonic cycles, the British and the American, reveal formal similarities that enable them to be grouped across standard literary-historical periods. Each text draws on allegory to dramatize how brute physicality emerges with an almost mechanical inevitability in conditions of imperial transition. Whether it arrives as a dark double (Stevenson), an atavistic exception (Agamben), or a degenerating patriarch (Franzen), this encoded violence finds each text allegorizing the dialectical interinvolvement between order and force that characterizes moments of imperial transition. Seen in light of Giovanni Arrighi's discussion of long-duration historical cycles, these formal similarities authorize a grouping across standard historical categories, an asynchronous contemporaneity that itself refocuses our attention on mediation as a critical category. By seeing texts as tactically reconfiguring their moments rather than mechanistically “reflecting” them or ambiguously “engaging” them, we reposition the critic in relation to the object and disclose the text's ability to use form (here, allegory) to mediate its contemporary situation.
Secular Blasphemies: Orhan Pamuk and the Turkish Novel
Authors: Göknar Erdağ
Published: July 2012

Turkish novelists have often contested the authoritarian tendencies of the republican state. Orhan Pamuk was charged with insulting Turkishness in 2005, emphasizing a long-standing opposition between author and state as well as between literature and secularism. Though Pamuk's trial gave him the status of dissident, it simultaneously ignored the formal innovations and political transgressions of his novels. This essay traces confrontations between Turkish literary modernity and secular modern state power in Pamuk's work and the Turkish novel. Such an analysis reveals that narratives of the nation-state (devlet), bound to the secularization thesis, have often been contested by Ottoman, Islamic, and Sufi contexts (signifying din). I argue that the unresolved opposition between the secular, material narratives of devlet and the sacred, redemptive narratives of din is productive of the modern Turkish novel and defines its literary modernity. Thus, Pamuk's dissidence also resides in modes of writing that contest the nation form and revise the secularization thesis through new representations of Turkish historiography, Istanbul cosmopolitanism, the Ottoman archive, political parody, and secular Sufism. Such literature that confronts representations of devlet with those of din constitutes the “secular blasphemies” that define the politics of the Turkish novel.
Observations of mean and turbulent flow structure in a free‐floating macrophyte root canopy
Authors: Downing‐Kunz Maureen A. , Stacey Mark T.
Published: July 2012

Lay Abstract

Free‐floating aquatic plants, or macrophytes, often grow in dense mats, and their feathery, unanchored roots form canopies below the water surface that can affect water flow and water quality. This study examines the physical interactions of an invasive species of free‐floating macrophyte, water hyacinth (Eichhornia crassipes), and the surrounding water to better understand how free‐floating macrophyte root canopies affect hydrodynamics. Experiments in an open‐channel flow chamber were conducted to examine the flow fields through and around root canopies. Acoustic Doppler velocity measurement revealed that water flow was deflected around the root canopy and was reduced within the canopy. Interestingly, the vertical pattern of the velocity in the roots was similar to what has been observed in leaf canopies of terrestrial and submerged aquatic vegetation. In these cases, an unstable velocity profile (one with an inflection point) gives rise to water column turbulence, which was observed at distances >50% of the length of the root canopy, culminating in a large wake region immediately downstream. Although mixing caused by turbulence increased outside the root canopy, it did not increase within the canopy, and so there was limited exchange of water between the root canopy and the open water. Because of this, we expect the time that water resides within the root canopy to be dominated by the slow mean flow velocity, rather than turbulence. This result helps to explain why the root canopies of free‐floating macrophytes can suffer from low levels of dissolved oxygen (hypoxia) and poor water quality, and suggests ways in which to improve the operational efficiency of natural water treatment systems relying on these types of plants.
Sca-1 is involved in the adhesion of myosphere cells to αVβ3 integrin
Authors: Penvose Ashley , Westerman Karen A.
Published: July 2012

A myosphere cell is a unique type of muscle stem cell that is able to maintain its pre-myogenic state in culture over time. These cells are propagated in culture as free-floating, non-adherent spheres. We believe that the 3-dimensional adhesive cell-cell interactions involved in maintaining the sphere-like myosphere structures are also involved in maintaining their longevity in culture. We found that Sca-1, which is highly expressed by myosphere cells, plays a role in the growth and the formation of the myospheres. In comparing adhesion molecules expressed by 3-dimensionally grown myosphere cells to those expressed by 2-dimensionally grown primary myoblasts, we found that there was a distinct difference in the expression of β3 integrin. Upon further investigation we discovered that there is an adhesive interaction between Sca-1+ cells and αVβ3 integrin. Here we show that Sca-1+ cells (myosphere cells and NIH3T3 cells) adhere to αVβ3 integrin and that Sca-1− cells (primary myoblasts) do not adhere. The interaction between Sca-1 and αVβ3 integrin was confirmed using antibody blocking, shRNA knockdown of Sca-1 in Sca-1+ cells, and by expressing Sca-1 cDNA in Sca-1− cells, which demonstrated that the level of adhesion of these cells to αVβ3 integrin was dependent on the presence of Sca-1. Additionally, we found that the co-expression of Sca-1 and β3 resulted in significantly greater adhesion of Sca-1+ cells to αVβ3 integrin. In conclusion, our data indicate that Sca-1 is involved in maintaining the 3-dimensional myosphere cell-cell contacts and that Sca-1 is involved in the binding of cells to αVβ3 integrin.
Electromagnetic fields at 2.45 GHz trigger changes in heat shock proteins 90 and 70 without altering apoptotic activity in rat thyroid gland
Authors: Misa Agustiño María José , Leiro José Manuel , Jorge Mora María Teresa , Rodríguez-González Juan Antonio , Jorge Barreiro Francisco Javier , Ares-Pena Francisco José , López-Martín Elena
Published: July 2012

Non-ionizing radiation at 2.45 GHz may modify the expression of genes that codify heat shock proteins (HSP) in the thyroid gland. Using the enzyme-linked immunosorbent assay (ELISA) technique, we studied levels of HSP-90 and HSP-70. We also used hematoxilin eosin to look for evidence of lesions in the gland and applied the DAPI technique of fluorescence to search for evidence of chromatin condensation and nuclear fragmentation in the thyroid cells of adult female Sprague-Dawley rats. Fifty-four rats were individually exposed for 30 min to 2.45 GHz radiation in a Gigahertz transverse electromagnetic (GTEM) cell at different levels of non-thermal specific absorption rate (SAR), which was calculated using the finite difference time domain (FDTD) technique. Ninety minutes after radiation, HSP-90 and HSP-70 had decreased significantly (P<0.01) after applying a SAR of 0.046±1.10 W/Kg or 0.104±5.10−3 W/Kg. Twenty-four hours after radiation, HSP-90 had partially recovered and HSP-70 had recovered completely. There were few indications of lesions in the glandular structure and signs of apoptosis were negative in all radiated animals. The results suggest that acute sub-thermal radiation at 2.45 GHz may alter levels of cellular stress in rat thyroid gland without initially altering their anti-apoptotic capacity.
Mechanosensitive mechanisms in transcriptional regulation
Authors: Mammoto Akiko , Mammoto Tadanori , Ingber Donald E.
Published: July 2012

Transcriptional regulation contributes to the maintenance of pluripotency, self-renewal and differentiation in embryonic cells and in stem cells. Therefore, control of gene expression at the level of transcription is crucial for embryonic development, as well as for organogenesis, functional adaptation, and regeneration in adult tissues and organs. In the past, most work has focused on how transcriptional regulation results from the complex interplay between chemical cues, adhesion signals, transcription factors and their co-regulators during development. However, chemical signaling alone is not sufficient to explain how three-dimensional (3D) tissues and organs are constructed and maintained through the spatiotemporal control of transcriptional activities. Accumulated evidence indicates that mechanical cues, which include physical forces (e.g. tension, compression or shear stress), alterations in extracellular matrix (ECM) mechanics and changes in cell shape, are transmitted to the nucleus directly or indirectly to orchestrate transcriptional activities that are crucial for embryogenesis and organogenesis. In this Commentary, we review how the mechanical control of gene transcription contributes to the maintenance of pluripotency, determination of cell fate, pattern formation and organogenesis, as well as how it is involved in the control of cell and tissue function throughout embryogenesis and adult life. A deeper understanding of these mechanosensitive transcriptional control mechanisms should lead to new approaches to tissue engineering and regenerative medicine.
Ubiquitylation of the chemokine receptor CCR7 enables efficient receptor recycling and cell migration
Authors: Schaeuble Karin , Hauser Mark A. , Rippl Alexandra V. , Bruderer Roland , Otero Carolina , Groettrup Marcus , Legler Daniel F.
Published: July 2012

The chemokine receptor CCR7 is essential for lymphocyte and dendritic cell homing to secondary lymphoid organs. Due to the ability to induce directional migration, CCR7 and its ligands CCL19 and CCL21 are pivotal for the regulation of the immune system. Here, we identified a novel function for receptor ubiquitylation in the regulation of the trafficking process of this G protein-coupled seven transmembrane receptor. We discovered that CCR7 is ubiquitylated in a constitutive, ligand-independent manner and that receptor ubiquitylation regulates the basal trafficking of CCR7 in the absence of chemokine. Upon CCL19 binding, we show that internalised CCR7 recycles back to the plasma membrane via the trans-Golgi network. An ubiquitylation-deficient CCR7 mutant internalised normally after ligand binding, but inefficiently recycled in immune cells and was transiently retarded in the TGN compartment of HEK293 transfectants. Finally, we demonstrate that the lack of CCR7 ubiquitylation profoundly impaired immune cell migration. Our results provide evidence for a novel function of receptor ubiquitylation in the regulation of CCR7 recycling and immune cell migration.
The centriolar satellite protein Cep131 is important for genome stability.
Authors: Staples Christopher J. , Myers Katie N. , Beveridge Ryan, D. D. , Patil Abhijit A. , Lee Alvin J. X. , Swanton Charles , Howell Michael , Boulton Simon J. , Collis Spencer J.
Published: July 2012

The centrosome acts as a centre for microtubule organisation and plays crucial roles in cell polarity, migration, growth and division. Cep131 has recently been described as a basal body component essential for cilium formation, though its function in non-ciliogenic cells is unknown. We identified human Cep131 in a screen for regulators of genome stability. We show that centrosomal localisation of Cep131 is cell cycle-regulated and requires both an intact microtubule network and a functional dynein-dynactin transport system. Cep131 is recruited to centriolar satellites by PCM1, and localised to the centriolar core region by both pericentrin and Cep290. Depletion of Cep131 results in a reduction in proliferation rate, centriole amplification, an increased frequency of multipolar mitosis, chromosomal instability, and an increase in post-mitotic DNA damage. These data therefore highlight the importance of human Cep131 for maintaining genomic integrity.
Heat induction of a novel Rad9 variant from a cryptic translation initiation site reduces mitotic commitment
Authors: Janes Simon , Schmidt Ulrike , Garrido Karim Ashour , Ney Nadja , Concilio Susanna , Zekri Mohamed , Caspari Thomas
Published: July 2012

Exposure of human cells to heat switches DNA damage signaling from genotoxic to temperature stress. This change reduces mitotic commitment at the expense of DNA break repair. The thermal alterations behind this switch remain elusive despite the successful use of heat to sensitize cancer cells to DNA breaks. Rad9 is a highly conserved subunit of the Rad9-Rad1-Hus1 (9-1-1) checkpoint-clamp that is loaded by Rad17 onto damaged chromatin. At the DNA, Rad9 activates the checkpoint kinases Rad3ATR and Chk1 to arrest cells in G2. Using Schizosaccharomyces pombe as a model eukaryote, we discovered a new variant of Rad9, Rad9-M50, expression of which is specifically induced by heat. High temperatures promote alternative translation from a cryptic initiation codon at methionine-50. This process is restricted to cycling cells and independent of the temperature-sensing MAP kinase pathway. While full-length Rad9 delays mitosis in the presence of DNA lesions, Rad9-M50 functions in a remodeled checkpoint pathway to reduce mitotic commitment at elevated temperatures. This remodeled pathway still relies on Rad1 and Hus1, but acts independently of Rad17. Heat-induction of Rad9-M50 ensures that Chk1 kinase remains in a hypo-phosphorylated state. Elevated temperatures specifically reverse the DNA damage-induced modification of Chk1 in a manner dependent on Rad9-M50. Taken together, heat reprograms the DNA damage checkpoint at the level of Chk1 by inducing a Rad9 variant that can act outside of the canonical 9-1-1 complex.
ZNRF2 is released from membranes by growth factors and, together with ZNRF1, regulates the Na+/K+ATPase
Authors: Hoxhaj Gerta , Najafov Ayaz , Toth Rachel , Campbell David G. , Prescott Alan R. , MacKintosh Carol
Published: July 2012

Here, we describe a phosphorylation-based reverse myristoyl switch for mammalian ZNRF2, and show that this E3 ubiquitin ligase and its sister protein ZNRF1 regulate the Na+/K+ pump (Na+/K+ATPase). N-myristoylation localizes ZNRF1 and ZNRF2 to intracellular membranes and enhances their activity. However, when ZNRF2 is phosphorylated in response to agonists including insulin and growth factors, it binds to 14-3-3 and is released into the cytosol. On membranes, ZNRF1 and ZNRF2 interact with the Na+/K+ATPase α1 subunit via their UBZ domains, while their RING domains interact with E2 proteins, predominantly Ubc13 that, together with Uev1a, mediates formation of Lys63-ubiquitin linkages. ZNRF1 and ZNRF2 can ubiquitylate the cytoplasmic loop encompassing the nucleotide-binding and phosphorylation regions of the Na+/K+ATPase α1 subunit. Ouabain, a Na+/K+ATPase inhibitor and therapeutic cardiac glycoside, decreases ZNRF1 protein levels, whereas knockdown of ZNRF2 inhibits the ouabain-induced decrease of cell surface and total Na+/K+ATPase α1 levels. Thus, ZNRF1 and ZNRF2 are new players in regulation of the ubiquitous Na+/K+ATPase that is tuned to changing demands in many physiological contexts.
MLL5 Maintains Genomic Integrity by Regulating the Stability of the Chromosomal Passenger Complex via a Functional Interaction with Borealin
Authors: Liu Jie , Cheng Fei , Deng Lih-Wen
Published: July 2012

Mixed Lineage Leukemia 5 (MLL5) is a versatile nuclear protein associated with multiple cellular events. We have shown previously that phosphorylation of MLL5 by Cdk1 is required for mitotic entry. In this paper, the function of MLL5 in mitotic regulation is further explored. SiRNA-mediated down regulation of MLL5 caused improper chromosome alignment at metaphase and resulted in failure in DNA segregation and cytokinesis. Mechanistic studies revealed that the chromosomal passenger complex (CPC), which plays a key role in chromosomal bi-orientation, was delocalized from inner centromere region due to proteasome-mediated degradation in MLL5-depleted cells. Biochemical analyses further demonstrated that the central domain of MLL5 interacted with the carboxyl terminus of Borealin, and the interaction is essential to maintain the stability of Borealin. Moreover, the mitotic defects in MLL5-depleted cells were rescued by over-expression of FLAG-MLL5, but not FLAG-MLL5 mutant which does not contain the central domain. Collectively, our results suggest that MLL5 functionally interacts with Borealin, facilitates the expression CPC, and hence contributes to mitotic fidelity and genomic integrity.
Tobacco TTG2 Quells Resistance to Pathogens by Sequestering NPR1 from Nuclear Localisation
Authors: Li Baoyan , Gao Rong , Cui Runzhi , Lü Beibei , Li Xiaojie , Zhao Yanying , You Zhengzheng , Tian Shuangmei , Dong Hansong
Published: July 2012

TRANSPARENT TESTA GLABRA (TTG) proteins that contain the WD40 protein interaction domain are implicated in multiple signalling pathways in plants. The salicylic acid (SA) signalling pathway regulates the resistance of plants to pathogens through defence responses via pathogenesis-related (PR) gene transcription activated by the NPR1 (nonexpresser of PR genes 1) protein, which contains WD40-binding domains. In this study, we report that tobacco (Nicotiana tabacum) NtTTG2 quells the resistance to viral and bacterial pathogens by repressing the nuclear localisation of NPR1 and SA/NPR1-regulated defence in plants. Nullification of the NtTTG2 protein production by silencing of the NtTTG2 gene resulted in the enhancement of resistance and PR gene expression, but NtTTG2 overexpression or NtTTG2 protein overproduction caused the opposite effects. Concurrent NtTTG2 and NPR1 gene silencing or NtTTG2 silencing in the absence of SA accumulation compensated for the compromised defence as a result of the NPR1 single-gene silencing or due to the absence of SA. To our surprise, NtTTG2 did not interact with NPR1 but was able to modulate the subcellular localisation of the NPR1 protein. When the production of NtTTG2 was nullified, NPR1 was found predominantly in the nucleus and the PR genes were expressed. On the contrary, when NtTTG2 accumulated in transgenic plants, a large proportion of NPR1 was retained in the cytoplasm and the PR genes were not expressed. These results suggest that NtTTG2 represses SA/NPR1-regulated defence by sequestering NPR1 from nuclear localisation and the transcriptional activation of the defence-response genes.
Spectra and Mean Association Number of Porphyrin J Aggregate
Authors: Matsuzawa Hideyo , Kobayashi Hiroshi , Maeda Tadakazu
Published: July 2012

The mean association number of a porphyrin J aggregate matured in acidic aqueous media (dye concentration, 7.9 × 10−6 M; 0.094 M HClO4; 20 °C) was determined to be 440 by measurements of the sedimentation and diffusion constants on ultracentrifuge. The aggregate forms in a rod-shaped microcrystalline consisting of more than 400 stacked porphyrins which grows for a period of two days in acidic aqueous solutions. MCD (magnetic circular dichroism) B-term extrema and hypochromic reduction observed with J- and H-bands in aggregate were elucidated on the basis of structure of J aggregate. The Stokes shift and bandwidths observed with J bands were also discussed using motional narrowing model. The characteristic J peak appears in an earlier stage of dye association (Dm, m < 10–12), while the transition energy as well as the bandwidth remains unchanged during aggregate growth (DN, 20 < N < 500). The second-order rate law of the association of precursor oligomers reveals the molar absorbance in JB peak (εJB) decreases with increasing association number N (N-dependent hypochromism, εJB/M−1 cm−1 = 0.5 × 106 + 1.65 × 107/N), which makes possible to determine N. Mean association numbers N = 400–500 can be predicted for the molar absorbance varying with mean association number N.
Monodisperse Activated Carbon Spheres from Colloidal Carbon Spheres by Steam Activation and Their Electrochemical Properties
Authors: Wu Yongjian , Jin Quan , Xie Chunlin , Cui Jianghu , Liu Yingliang
Published: July 2012

Monodisperse activated carbon spheres (ACSs) with high specific Brunauer–Emmett–Teller (BET) surface area were prepared from colloidal carbon spheres (CCSs) by steam activation. The effects of the gasification time on the surface properties of ACSs were investigated. The results exhibited that ACSs have a high specific surface area (2870 m2 g−1) and a large total pore volume (1.456 cm3 g−1). The electrochemical measurements were conducted by cyclic voltammetry. The results demonstrated that the specific capacitance of electrode material reaches 229 F g−1 at a sweep rate of 2 mV s−1.
Primary pulmonary cryptococcosis: evaluation of CT characteristics in 26 immunocompetent Chinese patients
Authors: Qu Yanjuan , Liu Guobing , Ghimire Prasanna , Liao Meiyan , Shi Heshui , Yang Guifang , Xu Liying , Wang Guanliang
Published: July 2012

Background

Discrepancies still exist in the diagnosis of primary pulmonary cryptococcosis in immunocompetent patients.

Purpose

To describe and evaluate radiological manifestations of pulmonary cryptococcosis in immunocompetent patients.

Material and Methods

Twenty-six histopathologically confirmed cases of pulmonary cryptococcosis were analyzed for clinical, pathological, and CT characteristics. Necessary statistical tests for differences in CT presentations and correlation analysis between clinical and CT characteristics were performed.

Results

The patients' ages ranged from 24 to 79 years, with 20 men and six women. Eighteen patients were symptomatic, with cough as the most common symptom ( n = 14, 53.8%). Nodules ( n = 21, 80.8%) were the most common CT findings. Eight cases presented with solitary and nine with multiple nodules, while 13 cases presented with irregular and 19 with ill-defined nodules. The halo sign was demonstrated, encompassing nodules in 14 of the 21 patients. Lesions were mainly localized in the lower lobes of the lungs ( n = 15, 57.7%) with peripheral distribution ( n = 18, 69.2%). Ground-glass opacities (GGOs) were more easily detected in older patients (66.7%, P <0.01). No significant differences in CT abnormalities were found between male and female patients.

Conclusion

Primary pulmonary cryptococcosis in immunocompetent patients exhibits certain CT characteristics. The typical presentation includes multiple nodules with the halo sign scattered in the peripheral field in the lower lobes of the bilateral lungs. This could contribute to diagnosis of the disease entity. However, vigilance should be exercised when facing GGOs, with or without nodules, in older patients.
The influence of body mass index and gender on coronary arterial attenuation with fixed iodine load per body weight at dual-source CT coronary angiography
Authors: Zhu Xiaomei , Zhu Yinsu , Xu Hai , Tang Lijun , Xu Yi
Published: July 2012

Background

Most of current coronary CT angiography protocols are not adapted to body weight (BW) or cardiac output and no literature about influence of gender on coronary attenuation are reported with administration of a fixed iodine load per BW.

Purpose

To determine the influence of body mass index (BMI) and gender on coronary arterial attenuation if contrast material dose is linearly adjusted to a patient's BW at dual-source CT coronary angiography (DSCT-CA).

Material and Methods

A total of 207 consecutive patients (mean age 60.6 years) undergoing DSCT-CA were included. Contrast material (370 mg I/mL) dose calculation was randomly categorized into two groups (Group1: 1.10 mL/kg for men and women; Group 2: men 1.10 mL/kg, women 0.99 mL/kg) and flow rate was calculated as dose was divided by scan time plus 8 s. Mean arterial attenuations between men and women were compared with respect to attenuations of ascending aorta (AA) above coronary ostia, left main coronary artery (LM), proximal segments of right coronary artery (RCA), left anterior descending (LAD), and left circumflex artery (LCX) in two groups, respectively. Attenuations of coronary arteries were correlated with BW and BMI with simple linear regression.

Results

The mean attenuations of AA, LM, RCA, LAD, and LCX were 407.8 ± 53.6 HU, 412.6 ± 55.4 HU, 411.4 ± 64.3 HU, 399.1 ± 56.7 HU, and 399.1 ± 60.2 HU, respectively, and there were no significant differences between men and women in group 1 (AA, P = 0.571; LM, P = 0.670; RCA, P = 0.737; LAD, P = 0.439, and LCX, P = 0.888). In group 2, the mean attenuations of AA, LM, RCA, LAD, and LCX in men were significantly higher than those in women (AA, P = 0.008; LM, P = 0.025; RCA, P = 0.017; LAD, P = 0.015, and LCX, P = 0.002). Positive linear regression between BW and attenuations of AA (R2 = 0.047, P = 0.02), LM (R2 = 0.036, P = 0.04), RCA (R2 = 0.080, P < 0.01), LAD (R2 = 0.078, P < 0.01), and LCX (R2 = 0.033, P = 0.05) was found in group 1, suggesting that attenuations of coronary arteries increased in heavier patients. Similarly, there was positive linear regression between BMI and attenuations of AA (R2 = 0.117, P < 0.01), LM (R2 = 0.090, P < 0.01), RCA (R2 = 0.138, P < 0.01), LAD (R2 = 0.111, P < 0.01), and LCX (R2 = 0.078, P < 0.01).

Conclusion

Men and women have similar coronary attenuations with a fixed iodine load per BW. BMI has a positive linear influence on arterial attenuation at DSCT-CA involving injection protocol with dose linearly tailored to BW. Excessive contrast material may inadvertently be given in heavier patients when the dose is determined by BW only. Contrast material dose may need to be tailored individually by BW and BMI.
Virtual non-contrast dual-energy CT compared to single-energy CT of the urinary tract: a prospective study
Authors: Lundin Margareta , Lidén Mats , Magnuson Anders , Mohammed Ahmed Abdulilah , Geijer Håkan , Andersson Torbjörn , Persson Anders
Published: July 2012

Background

Dual-energy computed tomography (DECT) has been shown to be useful for subtracting bone or calcium in CT angiography and gives an opportunity to produce a virtual non-contrast-enhanced (VNC) image from a series where contrast agents have been given intravenously. High noise levels and low resolution have previously limited the diagnostic value of the VNC images created with the first generation of DECT. With the recent introduction of a second generation of DECT, there is a possibility of obtaining VNC images with better image quality at hopefully lower radiation dose compared to the previous generation.

Purpose

To compare the image quality of the single-energy series to a VNC series obtained with a two generations of DECT scanners. CT of the urinary tract was used as a model.

Material and Methods

Thirty patients referred for evaluation of hematuria were examined with an older system (Somatom Definition) and another 30 patients with a new generation (Somatom Definition Flash). One single-energy series was obtained before and one dual-energy series after administration of intravenous contrast media. We created a VNC series from the contrast-enhanced images. Images were assessed concerning image quality with a visual grading scale evaluation of the VNC series with the single-energy series as gold standard.

Results

The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, OR 11.5–67.3 for the Definition and OR 2.1–2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than Definition.

Conclusion

Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images. However, the difference is smaller with the new compared to the older system.
Magnetic resonance imaging of radiation-induced brain injury using targeted microparticles of iron oxide
Authors: Zhu Yeqing , Ling You , Zhong Jinglian , Liu Xueguo , Wei Kun , Huang Suiqiao
Published: July 2012

Background

Radiation-induced brain injury (RBI) is the most serious complication of primary and metastatic brain and neck malignant tumors following radiation therapy. However, at present, RBI is difficult to diagnose in the early period. Recently, studies have demonstrated that the early stage of RBI is characterized by an inflammatory reaction, and that intercellular adhesion molecule-1 (ICAM-1) is significantly up-regulated in the irradiated brain tissues.

Purpose

To provide an early diagnosis of RBI using molecular magnetic resonance imaging (MRI) with microparticles of iron oxide (MPIO) targeted to ICAM-1 in the vascular endothelium of brains.

Material and Methods

A monoclonal antibody against ICAM-1 was conjugated to MPIO to form the targeted MRI contrast agent ICAM-MPIO. The adhesion of ICAM-MPIO to endothelial cells was quantified by optical imaging and MRI. Sprague-Dawley rats were irradiated to establish an animal model of the early period of RBI. ICAM-MPIO and free-MPIO were injected via tail vein, respectively. T2 signal intensity and T2 values of the irradiated brains and normal brains were subsequently evaluated by MRI.

Results

In vitro, the adhesion of ICAM-MPIO to the activated endothelial cells was 5 ± 0.5-fold greater than to the non-stimulated cells, which could be detected by optical imaging and MRI (R2 = 1.0, P < 0.01). In vivo, ICAM-MPIO caused a marked negative MRI contrast effect in irradiated brains. As compared with brains without irradiation, the specific contrast effect increased more than seven-fold after administration of ICAM-MPIO (F = 751.495, P < 0.05).

Conclusion

MPIO coated with monoclonal antibody of ICAM-1 could be used for detecting the early period of RBI by optical imaging and MRI.
How Can Achievement Induce Loyalty? A Combination of the Goal-Setting Theory and Flow Theory Perspectives
Authors: Teng Ching-I , Lo Shao-Kang , Li Yi-Jhen
Published: July 2012

The motivation theory has identified achievement as a critical factor for online game play. However, how achievement induces gamer loyalty (the intention to play a certain game continuously) has not been explored. This study thus used the goal-setting theory to identify two achievement-related motivators: achievement striving (desire for achievements) and competence (confidence at obtaining achievements). Moreover, flow theory was used to develop hypotheses on how achievement striving and competence induce gamer loyalty. Based on the responses from 994 online gamers, our results indicate that achievement striving and competence among gamers are positively related to skill and perceived challenge. Additionally, skill and perceived challenge are positively related to flow, and flow is positively related to gamer loyalty. We recommend that game providers target individuals who are high in achievement striving and competence, or increase gamer desire for those motivators at obtaining achievements, in order to construct a loyal gamer base.
Planning for an Aging Fleet of Shuttle Vehicles with Simulation
Authors: Saltzman Robert M.
Published: July 2012

San Francisco State University operates a small but aging fleet of shuttle vehicles that facilitate travel by its affiliates to, from, and around campus. Its shuttle system is primarily intended to supplement municipal bus service in connecting the university to the nearest Bay Area Rapid Transit train station in Daly City, California, approximately a mile and a half south of campus. This article presents an animated discrete-event simulation model of the system that can be used by campus planners to make capital improvement decisions about the fleet. In particular, the model can help identify the best type of shuttle (in terms of capacity and number of doors) to replace the older existing vehicles. Furthermore, experimentation with the model can predict how different fleet configurations would accommodate various increases in ridership; e.g., if ridership increases 40% over the next few years, a satisfactory level of service can be maintained by replacing just two of the fleet's six existing shuttles with new 39-passenger, two-door, low-floor vehicles.
Plan Format and Participation in 401(k) Plans: The Moderating Role of Investor Knowledge
Authors: Morrin Maureen , Broniarczyk Susan M. , Inman J. Jeffrey
Published: July 2012

There is continuing concern that many people are not saving enough for retirement. The authors conduct three studies to determine whether simple alterations to the format of 401(k) plans can increase plan participation rates, especially among people with low levels of financial knowledge. In Study 1, offering a larger number of funds for investment reduces plan participation among low-knowledge investors, unless the plan also offers a target retirement date (i.e., life-cycle fund) option. In Study 2, the authors find those with low knowledge are more likely to participate if the funds offered for investment are grouped by asset class rather than listed alphabetically. In Study 3, the authors find that participation increases when fund descriptions include star ratings (but not fund style boxes). They also find that star ratings increase decision satisfaction among low-knowledge investors because of a reduction in perceived task difficulty. Limitations, implications, and further research are discussed.
Targeting Social Messages with Emotions of Change: The Call for Optimism
Authors: Peter Paula C. , Honea Heather
Published: July 2012

With the goal to improve the effectiveness and impact of communication messages delivered by social marketers, this research focuses on understanding variables that may be relevant in developing effective social marketing messages for the substantive domain of disposable plastic bottled water consumption. The authors examine the affective states associated with different stages of consumer change related to wasteful repetitive consumption behavior (i.e., disposable plastic bottled water consumption). With two empirical studies, the authors identify guilt, hope, pride, and optimism as relevant triggers of increased intent to manage personal consumption in pursuit of a desirable social outcome (i.e., reduction of disposable plastic bottled water consumption). While guilt, hope, and pride are relevant self-referential emotions to initial stages of change (Study 1), optimism is a principal construct in motivating people to adopt and maintain the behavior over time (Study 2). These results have valuable theoretical and practical implications for social marketers and public policy makers.
Environmental epigenetics: a role in endocrine disease?
Authors: Fleisch Abby F , Wright Robert O , Baccarelli Andrea A
Published: July 2012

Endocrine disrupting chemicals that are structurally similar to steroid or amine hormones have the potential to mimic endocrine endpoints at the receptor level. However, more recently, epigenetic-induced alteration in gene expression has emerged as an alternative way in which environmental compounds may exert endocrine effects. We review concepts related to environmental epigenetics and relevance for endocrinology through three broad examples: 1) effect of early-life nutritional exposures on future obesity and insulin resistance, 2) effect of lifetime environmental exposures such as ionizing radiation on endocrine cancer risk, and 3) potential for compounds previously classified as endocrine disrupting to additionally or alternatively exert effects through epigenetic mechanisms. The field of environmental epigenetics is still nascent, and additional studies are needed to confirm and reinforce data derived from animal models and preliminary human studies. Current evidence suggests that environmental exposures may significantly impact expression of endocrine-related genes and thereby affect clinical endocrine outcomes.
Chronic exposure to leucine in vitro induces β-cell dysfunction in INS-1E cells and mouse islets
Authors: Liu Zhenping , Jeppesen Per Bendix , Gregersen Søren , Larsen Lotte Bach , Hermansen Kjeld
Published: July 2012

Chronic hyperglycemia and hyperlipidemia cause deleterious effects on β-cell function. Interestingly, increased circulating amino acid (AA) levels are also a characteristic of the prediabetic and diabetic state. The chronic effects of AAs on β-cell function remain to be determined. Isolated mouse islets and INS-1E cells were incubated with or without excess leucine. After 72 h, leucine increased basal insulin secretion and impaired glucose-stimulated insulin secretion in both mouse islets and INS-1E cells, corroborating the existence of aminoacidotoxicity-induced β-cell dysfunction. This took place concomitantly with alterations in proteins and genes involved in insulin granule transport, trafficking (e.g. collapsin response mediator protein 2 and GTP-binding nuclear protein Ran), insulin signal transduction (proteasome subunit α type 6), and the oxidative phosphorylation pathway (cytochromecoxidase). Leucine downregulated insulin 1 gene expression but upregulated pancreas duodenum homeobox 1 and insulin 2 mRNA expressions. Importantly, cholesterol (CH) accumulated in INS-1E cells concomitantly with upregulation of enzymes involved in CH biosynthesis (e.g. 3-hydroxy-3-methylglutaryl-CoA reductase, mevalonate (diphospho) decarboxylase, and squalene epoxidase) and LDL receptor, whereas triglyceride content was decreased. Our findings indicate that chronic exposure to elevated levels of leucine may have detrimental effects on both β-cell function and insulin sensitivity. Aminoacidotoxicity may play a pathogenic role in the development of type 2 diabetes.
Articulando escolas de pensamento estratégico através da tecnologia da informação
Authors: Ramos Eduardo Augusto de Andrade , Joia Luiz Antonio
Published: July 2012

Na medida em que as organizações investem crescentemente em tecnologia da informação (TI) e tal tecnologia influencia cada vez mais os seus processos de negócios, o impacto da utilização da TI no desempenho das organizações tem sido alvo de grande interesse. Para análise desse impacto, diversos modelos têm sido desenvolvidos. Por trás desses modelos, duas grandes escolas de estratégia - consideradas antagônicas - se sobressaem e têm sido utilizadas para modelar o papel da TI na estratégia das organizações: a escola de posicionamento e a escola de recursos. O objetivo deste artigo teórico é propor uma articulação entre essas duaslinhas de pensamento estratégico, tendo como elo de ligação o papel estratégico da TI nas firmas. Dessa forma,através de uma abordagem teórico-exploratória, esse artigo formula quatro proposições que visam integrar essas duas escolas à luz do papel da TI nas organizações, para ajudar acadêmicos e practitioners a melhor entenderem o papel estratégico da TI nas empresas.
Criação de jornal na avaliação de aspectos comportamentais ligados à gestão de pessoas
Authors: Cavedon Neusa
Published: July 2012

Este artigo procura apresentar uma experiência de avaliação educacional, alinhada com uma lógica específica desenvolvida pelos estudos educacionais, na qual a avaliação deve servir como um feedback para os professores e para as escolas. Essa visão (da avaliação baseada em diagnóstico e formativa) procura desenvolver nos discentes a capacidade de planejar, questionar, criticar, descobrir, criar, comunicar, transformar e conhecer, entre outras possibilidades.