bluuebunny/crossref_metadata_2025 huggingface dataset:
Up-regulation of METCAM/MUC18 promotes motility, invasion, and tumorigenesis of human breast cancer cells
Authors: Zeng Guo-fang , Cai Shao-xi , Wu Guang-Jer
Published: April 2011

Background

Conflicting research has identified METCAM/MUC18, an integral membrane cell adhesion molecule (CAM) in the Ig-like gene super-family, as both a tumor promoter and a tumor suppressor in the development of breast cancer. To resolve this, we have re-investigated the role of this CAM in the progression of human breast cancer cells.

Methods

Three breast cancer cell lines were used for the tests: one luminal-like breast cancer cell line, MCF7, which did not express any METCAM/MUC18, and two basal-like breast cancer cell lines, MDA-MB-231 and MDA-MB-468, which expressed moderate levels of the protein.

MCF7 cells were transfected with the human METCAM/MUC18 cDNA to obtain G418-resistant clones which expressed the protein and were used for testing effects of human METCAM/MUC18 expression on in vitro motility and invasiveness, and in vitro and in vivo tumorigenesis. Both MDA-MB-231 and MDA-MB-468 cells already expressed METCAM/MUC18. They were directly used for in vitro tests in the presence and absence of an anti-METCAM/MUC18 antibody.

Results

In MCF7 cells, enforced METCAM/MUC18 expression increased in vitro motility, invasiveness, anchorage-independent colony formation (in vitro tumorigenesis), and in vivo tumorigenesis. In both MDA-MB-231 and MDA-MB-468 cells, the anti-METCAM/MUC18 antibody inhibited both motility and invasiveness. Though both MDA-MB-231 and MDA-MB-468 cells established a disorganized growth in 3D basement membrane culture assay, the introduction of the anti-METCAM/MUC18 antibody completely destroyed their growth in the 3D culture.

Conclusion

These findings support the notion that human METCAM/MUC18 expression promotes the progression of human breast cancer cells by increasing their motility, invasiveness and tumorigenesis.
Prediction of outcome after diagnosis of metachronous contralateral breast cancer
Authors: Alkner Sara , Bendahl Pär-Ola , Fernö Mårten , Manjer Jonas , Rydén Lisa
Published: April 2011

Background

Although 2-20% of breast cancer patients develop a contralateral breast cancer (CBC), prognosis after CBC is still debated. Using a unique patient cohort, we have investigated whether time interval to second breast cancer (BC2) and mode of detection are associated to prognosis.

Methods

Information on patient-, tumour-, treatment-characteristics, and outcome was abstracted from patients' individual charts for all patients diagnosed with metachronous CBC in the Southern Healthcare Region of Sweden from 1977-2007. Distant disease-free survival (DDFS) and risk of distant metastases were primary endpoints.

Results

The cohort included 723 patients with metachronous contralateral breast cancer as primary breast cancer event. Patients with less than three years to BC2 had a significantly impaired DDFS (p = 0.01), and in sub-group analysis, this effect was seen primarily in patients aged <50. By logistic regression analysis, patients diagnosed with BC2 within routine follow-up examinations had a significantly lower risk of developing metastases compared to those who were symptomatic at diagnosis (p < 0.0001). Chemotherapy given after breast BC1 was a negative prognostic factor for DDFS, whereas endocrine treatment and radiotherapy given after BC2 improved DDFS.

Conclusions

In a large cohort of patients with CBC, we found the time interval to BC2 to be a strong prognostic factor for DDFS in young women and mode of detection to be related to risk of distant metastases. Future studies of tumour biology of BC2 in relation to prognostic factors found in the present study can hopefully provide biological explanations to these findings.
A Kallikrein 15 (KLK15) single nucleotide polymorphism located close to a novel exon shows evidence of association with poor ovarian cancer survival
Authors: Batra Jyotsna , Nagle Christina M , O'Mara Tracy , Higgins Melanie , Dong Ying , Tan Olivia L , Lose Felicity , Skeie Lene Marie , Srinivasan Srilakshmi , Bolton Kelly L , Song Honglin , Ramus Susan J , Gayther Simon A , Pharoah Paul DP , Kedda Mary-Anne , Spurdle Amanda B , Clements Judith A
Published: April 2011

Background

KLK15 over-expression is reported to be a significant predictor of reduced progression-free survival and overall survival in ovarian cancer. Our aim was to analyse the KLK15 gene for putative functional single nucleotide polymorphisms (SNPs) and assess the association of these and KLK15 HapMap tag SNPs with ovarian cancer survival.

Results

In silico analysis was performed to identify KLK15 regulatory elements and to classify potentially functional SNPs in these regions. After SNP validation and identification by DNA sequencing of ovarian cancer cell lines and aggressive ovarian cancer patients, 9 SNPs were shortlisted and genotyped using the Sequenom iPLEX Mass Array platform in a cohort of Australian ovarian cancer patients (N = 319). In the Australian dataset we observed significantly worse survival for the KLK15 rs266851 SNP in a dominant model (Hazard Ratio (HR) 1.42, 95% CI 1.02-1.96). This association was observed in the same direction in two independent datasets, with a combined HR for the three studies of 1.16 (1.00-1.34). This SNP lies 15bp downstream of a novel exon and is predicted to be involved in mRNA splicing. The mutant allele is also predicted to abrogate an HSF-2 binding site.

Conclusions

We provide evidence of association for the SNP rs266851 with ovarian cancer survival. Our results provide the impetus for downstream functional assays and additional independent validation studies to assess the role of KLK15 regulatory SNPs and KLK15 isoforms with alternative intracellular functional roles in ovarian cancer survival.
The influence of psychiatric screening in healthy populations selection: a new study and meta-analysis of functional 5-HTTLPR and rs25531 polymorphisms and anxiety-related personality traits
Authors: Minelli Alessandra , Bonvicini Cristian , Scassellati Catia , Sartori Riccardo , Gennarelli Massimo
Published: April 2011

Background

A genetic liability for anxiety-related personality traits in healthy subjects has been associated with the functional serotonin transporter promoter polymorphism (5-HTTLPR), although the data are somewhat conflicting. Moreover, only one study has investigated the functional significance of the 5-HTTLPR/rs25531 haplotypes in relation to anxiety traits in healthy subjects. We tested whether the 5-HTTLPR polymorphism and the 5-HTTLPR/rs25531 haplotypes are linked to Harm Avoidance (HA) using an association study (STUDY I) and a meta-analytic approach (STUDY II).

Methods

STUDY I: A total of 287 unrelated Italian volunteers were screened for DSM-IV Axis I disorders and genotyped for the 5-HTTLPR and rs25531 (A/G) polymorphisms. Different functional haplotype combinations were also analyzed. STUDY II: A total of 44 studies were chosen for a meta-analysis of the putative association between 5-HTTLPR and anxiety-related personality traits.

Results

STUDY I: In the whole sample of 287 volunteers, we found that the SS genotype and S'S' haplotypes were associated with higher scores on HA. However, because the screening assessed by Mini-International Neuropsychiatric Interview (M.I.N.I.) showed the presence of 55 volunteers affected by depression or anxiety disorders, we analyzed the two groups ("disordered" and "healthy") separately. The data obtained did indeed confirm that in the "healthy" group, the significant effects of the SS genotype and S'S' haplotypes were lost, but they remained in the "disordered" group. STUDY II: The results of the 5-HTTLPR meta-analysis with anxiety-related traits in the whole sample confirmed the association of the SS genotype with higher anxiety-related traits scores in Caucasoids; however, when we analyzed only those studies that used structured psychiatric screening, no association was found.

Conclusions

This study demonstrates the relevance to perform analyses on personality traits only in DSM-IV axis I disorder-free subjects. Furthermore, we did not find an association between functional serotonin transporter gene polymorphisms and anxiety traits in healthy subjects screened through a structured psychiatric interview.
The impact of sagittal balance on clinical results after posterior interbody fusion for patients with degenerative spondylolisthesis: A Pilot study
Authors: Kim Mi Kyung , Lee Sun-Ho , Kim Eun-Sang , Eoh Whan , Chung Sung-Soo , Lee Chong-Suh
Published: April 2011

Background

Comparatively little is known about the relation between the sagittal vertical axis and clinical outcome in cases of degenerative lumbar spondylolisthesis. The objective of this study was to determine whether lumbar sagittal balance affects clinical outcomes after posterior interbody fusion. This series suggests that consideration of sagittal balance during posterior interbody fusion for degenerative spondylolisthesis can yield high levels of patient satisfaction and restore spinal balance

Methods

A retrospective study of clinical outcomes and a radiological review was performed on 18 patients with one or two level degenerative spondylolisthesis. Patients were divided into two groups: the patients without improvement in pelvic tilt, postoperatively (Group A; n = 10) and the patients with improvement in pelvic tilt postoperatively (Group B; n = 8). Pre- and postoperative clinical outcome surveys were administered to determine Visual Analogue Pain Scores (VAS) and Oswestry disability index (ODI). In addition, we evaluated full spine radiographic films for pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), thoracic kyphosis (TK), lumbar lordosis (LL), sacrofemoral distance (SFD), and sacro C7 plumb line distance (SC7D)

Results

All 18 patients underwent surgery principally for the relief of radicular leg pain and back pain. In groups A and B, mean preoperative VAS were 6.85 and 6.81, respectively, and these improved to 3.20 and 1.63 at last follow-up. Mean preoperative ODI were 43.2 and 50.4, respectively, and these improved to 23.6 and 18.9 at last follow-up. In spinopelvic parameters, no significant difference was found between preoperative and follow up variables except PT in Group A. However, significant difference was found between the preoperative and follows up values of PT, SS, TK, LL, and SFD/SC7D in Group B. Between parameters of group A and B, there is borderline significance on preoperative PT, preoperative LL and last follow up SS.

Correlation analysis revealed the VAS improvements in Group A were significantly related to postoperative lumbar lordosis (Pearson's coefficient = -0.829; p = 0.003). Similarly, ODI improvements were also associated with postoperative lumbar lordosis (Pearson's coefficient = -0.700; p = 0.024). However, in Group B, VAS and ODI improvements were not found to be related to postoperative lumbar lordosis and to spinopelvic parameters.

Conclusion

In the current series, patients improving PT after fusion were found to achieve good clinical outcomes in degenerative spondylolisthesis. Overall, our findings show that it is important to quantify sagittal spinopelvic parameters and promote sagittal balance when performing lumbar fusion for degenerative spondylolisthesis.
Genetic response to metabolic fluctuations: correlation between central carbon metabolism and DNA replication in Escherichia coli
Authors: Maciąg Monika , Nowicki Dariusz , Janniere Laurent , Szalewska-Pałasz Agnieszka , Węgrzyn Grzegorz
Published: April 2011

Background

Until now, the direct link between central carbon metabolism and DNA replication has been demonstrated only in Bacillus. subtilis. Therefore, we asked if this is a specific phenomenon, characteristic for this bacterium and perhaps for its close relatives, or a more general biological rule.

Results

We found that temperature-sensitivity of mutants in particular genes coding for replication proteins could be suppressed by deletions of certain genes coding for enzymes of the central carbon metabolism. Namely, the effects of dnaA46(ts) mutation could be suppressed by dysfunction of pta or ackA, effects of dnaB(ts) by dysfunction of pgi or pta, effects of dnaE486(ts) by dysfunction of tktB, effects of dnaG(ts) by dysfunction of gpmA, pta or ackA, and effects of dnaN159(ts) by dysfunction of pta or ackA. The observed suppression effects were not caused by a decrease in bacterial growth rate.

Conclusions

The genetic correlation exists between central carbon metabolism and DNA replication in the model Gram-negative bacterium, E. coli. This link exists at the steps of initiation and elongation of DNA replication, indicating the important global correlation between metabolic status of the cell and the events leading to cell reproduction.
Synthesis of freestanding HfO2 nanostructures
Authors: Kidd Timothy , O'Shea Aaron , Boyle Kayla , Wallace Jeff , Strauss Laura
Published: April 2011

Two new methods for synthesizing nanostructured HfO2 have been developed. The first method entails exposing HfTe2 powders to air. This simple process resulted in the formation of nanometer scale crystallites of HfO2. The second method involved a two-step heating process by which macroscopic, freestanding nanosheets of HfO2 were formed as a byproduct during the synthesis of HfTe2. These highly two-dimensional sheets had side lengths measuring up to several millimeters and were stable enough to be manipulated with tweezers and other instruments. The thickness of the sheets ranged from a few to a few hundred nanometers. The thinnest sheets appeared transparent when viewed in a scanning electron microscope. It was found that the presence of Mn enhanced the formation of HfO2 by exposure to ambient conditions and was necessary for the formation of the large scale nanosheets. These results present new routes to create freestanding nanostructured hafnium dioxide.

PACS: 81.07.-b, 61.46.Hk, 68.37.Hk.
Enhancements of thermal conductivities with Cu, CuO, and carbon nanotube nanofluids and application of MWNT/water nanofluid on a water chiller system
Authors: Liu MinSheng , Lin Mark ChingCheng , Wang ChiChuan
Published: April 2011

In this study, enhancements of thermal conductivities of ethylene glycol, water, and synthetic engine oil in the presence of copper (Cu), copper oxide (CuO), and multi-walled carbon nanotube (MWNT) are investigated using both physical mixing method (two-step method) and chemical reduction method (one-step method). The chemical reduction method is, however, used only for nanofluid containing Cu nanoparticle in water. The thermal conductivities of the nanofluids are measured by a modified transient hot wire method. Experimental results show that nanofluids with low concentration of Cu, CuO, or carbon nanotube (CNT) have considerably higher thermal conductivity than identical base liquids. For CuO-ethylene glycol suspensions at 5 vol.%, MWNT-ethylene glycol at 1 vol.%, MWNT-water at 1.5 vol.%, and MWNT-synthetic engine oil at 2 vol.%, thermal conductivity is enhanced by 22.4, 12.4, 17, and 30%, respectively. For Cu-water at 0.1 vol.%, thermal conductivity is increased by 23.8%. The thermal conductivity improvement for CuO and CNT nanofluids is approximately linear with the volume fraction. On the other hand, a strong dependence of thermal conductivity on the measured time is observed for Cu-water nanofluid. The system performance of a 10-RT water chiller (air conditioner) subject to MWNT/water nanofluid is experimentally investigated. The system is tested at the standard water chiller rating condition in the range of the flow rate from 60 to 140 L/min. In spite of the static measurement of thermal conductivity of nanofluid shows only 1.3% increase at room temperature relative to the base fluid at volume fraction of 0.001 (0.1 vol.%), it is observed that a 4.2% increase of cooling capacity and a small decrease of power consumption about 0.8% occur for the nanofluid system at a flow rate of 100 L/min. This result clearly indicates that the enhancement of cooling capacity is not just related to thermal conductivity alone. Dynamic effect, such as nanoparticle dispersion may effectively augment the system performance. It is also found that the dynamic dispersion is comparatively effective at lower flow rate regime, e.g., transition or laminar flow and becomes less effective at higher flow rate regime. Test results show that the coefficient of performance of the water chiller is increased by 5.15% relative to that without nanofluid.
Histone deacetylase 3, not histone deacetylase 2, interacts with the major immediate early locus of human cytomegalovirus
Authors: Huang Ying , Tang Qiyi , Nguyen Michael , Dulal Kalpana , Wang Weijia , Zhu Hua
Published: April 2011

Evidence suggests that genome chromatinization and the posttranslational modification of histones are involved in the regulation of viral gene expression, including the human cytomegalovirus (HCMV). We performed a ChIP-on-Chip assay to determine whether histone deacetylases (HDACs) interact with HCMV genomic DNA on a global level. Surprisingly, we found that HDAC3, but not HDAC2, interacts not only with the major immediate early (MIE) promoter but also with the entire MIE locus, suggesting a heterogeneous interaction of HDAC3 with HCMV DNA. The interaction of HDAC3 with the MIE region is related to inhibition of viral replication because HDAC3 inhibitors enhanced HCMV replication.
Thrombospondin 1 is a key mediator of transforming growth factor β-mediated cell contractility in systemic sclerosis via a mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)-dependent mechanism
Authors: Chen Yunliang , Leask Andrew , Abraham David J , Kennedy Laura , Shi-wen Xu , Denton Christopher P , Black Carol M , Verjee Liaquat S , Eastwood Mark
Published: April 2011

Background

The mechanism underlying the ability of fibroblasts to contract a collagen gel matrix is largely unknown. Fibroblasts from scarred (lesional) areas of patients with the fibrotic disease scleroderma show enhanced ability to contract collagen relative to healthy fibroblasts. Thrombospondin 1 (TSP1), an activator of latent transforming growth factor (TGF)β, is overexpressed by scleroderma fibroblasts. In this report we investigate whether activation of latent TGFβ by TSP1 plays a key role in matrix contraction by normal and scleroderma fibroblasts.

Methods

We use the fibroblast populated collagen lattices (FPCL) model of matrix contraction to show that interfering with TSP1/TGFβ binding and knockdown of TSP1 expression suppressed the contractile ability of normal and scleroderma fibroblasts basally and in response to TGFβ. Previously, we have shown that ras/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) mediates matrix contraction basally and in response to TGFβ.

Results

During mechanical stimulation in the FPCL system, using a multistation tensioning-culture force monitor (mst-CFM), TSP1 expression and p-ERK activation in fibroblasts are enhanced. Inhibiting TSP1 activity reduced the elevated activation of MEK/ERK and expression of key fibrogenic proteins. TSP1 also blocked platelet-derived growth factor (PDGF)-induced contractile activity and MEK/ERK activation.

Conclusions

TSP1 is a key mediator of matrix contraction of normal and systemic sclerosis fibroblasts, via MEK/ERK.
Expression and Roles of Pannexins in ATP Release in the Pituitary Gland
Authors: Li Shuo , Bjelobaba Ivana , Yan Zonghe , Kucka Marek , Tomić Melanija , Stojilkovic Stanko S.
Published: April 2011

Pannexins are a newly discovered three-member family of proteins expressed in the brain and peripheral tissues that belong to the superfamily of gap junction proteins. However, in mammals pannexins do not form gap junctions, and their expression and function in the pituitary gland have not been studied. Here we show that the rat pituitary gland expresses mRNA and protein transcripts of pannexins 1 and 2 but not pannexin 3. Pannexin 1 was more abundantly expressed in the anterior lobe, whereas pannexin 2 was more abundantly expressed in the intermediate and posterior pituitary. Pannexin 1 was identified in corticotrophs and a fraction of somatotrophs, the S100-positive pituicytes of the posterior pituitary and AtT-20 (mouse pituitary adrenocorticotropin-secreting cells) and rat immortalized pituitary cells secreting prolactin, whereas pannexin 2 was detected in the S100-positive folliculostellate cells of the anterior pituitary, melanotrophs of the intermediate lobe, and vasopressin-containing axons and nerve endings in the posterior lobe. Overexpression of pannexins 1 and 2 in AtT-20 pituitary cells enhanced the release of ATP in the extracellular medium, which was blocked by the gap junction inhibitor carbenoxolone. Basal ATP release in At-T20 cells was also suppressed by down-regulating the expression of endogenous pannexin 1 but not pannexin 2 with their short interfering RNAs. These results indicate that pannexins may provide a pathway for delivery of ATP, which is a native agonist for numerous P2X cationic channels and G protein-coupled P2Y receptors endogenously expressed in the pituitary gland.
Substance P (SP)-Neurokinin-1 Receptor (NK-1R) Alters Adipose Tissue Responses to High-Fat Diet and Insulin Action
Authors: Karagiannides Iordanes , Stavrakis Dimitris , Bakirtzi Kyriaki , Kokkotou Efi , Pirtskhalava Tamara , Nayeb-Hashemi Hamed , Bowe Collin , Bugni James M. , Nuño Miriam , Lu Bao , Gerard Norma P. , Leeman Susan E. , Kirkland James L. , Pothoulakis Charalabos
Published: April 2011

Peripheral administration of a specific neurokinin-1 receptor (NK-1R) antagonist to mice leads to reduced weight gain and circulating levels of insulin and leptin after high-fat diet (HFD). Here, we assessed the contribution of substance P (SP) and NK-1R in diet-induced obesity using NK-1R deficient [knockout (KO)] mice and extended our previous findings to show the effects of SP-NK-1R interactions on adipose tissue-associated insulin signaling and glucose metabolic responses. NK-1R KO and wild-type (WT) littermates were fed a HFD for 3 wk, and obesity-associated responses were determined. Compared with WT, NK-1 KO mice show reduced weight gain and circulating levels of leptin and insulin in response to HFD. Adiponectin receptor mRNA levels are higher in mesenteric fat and liver in NK-1 KO animals compared with WT, after HFD. Mesenteric fat from NK-1R KO mice fed with HFD has reduced stress-activated protein kinase/c-Jun N-terminal kinase and protein kinase Cθ activation compared with WT mice. After glucose challenge, NK-1R KO mice remove glucose from the circulation more efficiently than WT and pair-fed controls, suggesting an additional peripheral effect of NK-1R-mediated signaling on glucose metabolism. Glucose uptake experiments in isolated rat adipocytes showed that SP directly inhibits insulin-mediated glucose uptake. Our results further establish a role for SP-NK-1R interactions in adipose tissue responses, specifically as they relate to obesity-associated pathologies such as glucose intolerance and insulin resistance. Our results highlight this pathway as an important therapeutic approach for type 2 diabetes.
mRNA isoform diversity can obscure detection of miRNA-mediated control of translation
Authors: Clancy Jennifer L. , Wei Grace H. , Echner Nicole , Humphreys David T. , Beilharz Traude H. , Preiss Thomas
Published: April 2011

Reporter-based studies support inhibition of translation at the level of initiation as a substantial component of the miRNA mechanism, yet recent global analyses have suggested that they predominantly act through decreasing target mRNA stability. Cells commonly coexpress several processing isoforms of an mRNA, which may also differ in their regulatory untranslated regions (UTR). In particular, cancer cells are known to express high levels of short 3′ UTR isoforms that evade miRNA-mediated regulation, whereas longer 3′ UTRs predominate in nontransformed cells. To test whether mRNA isoform diversity can obscure detection of miRNA-mediated control at the level of translation, we assayed the responses of 11 endogenous let-7 targets to inactivation of this miRNA in HeLa cells, an intensively studied model system. We show that translational regulation in many cases appears to be modest when measuring the composite polysome profile of all extant isoforms of a given mRNA by density ultracentrifugation. In contrast, we saw clear effects at the level of translation initiation for multiple examples when selectively profiling mRNA isoforms carrying the 5′ or 3′ untranslated regions that were actually permissive to let-7 action, or when let-7 and a second targeting miRNA were jointly manipulated. Altogether, these results highlight a caveat to the mechanistic interpretation of data from global miRNA target analyses in transformed cells. Importantly, they reaffirm the importance of translational control as part of the miRNA mechanism in animal cells.
“‘It's about us!’. Violence and Narrative Memory in Post 9/11 American Theatre
Authors: Saal Ilka
Published: April 2011

Trauma work entails not only the mending of physical and psychic wounds, but also the reconstruction of narrative structures. In the wake of September 11, there were, as Don DeLillo put it, “1000, 000 stories […] waiting to be told.” And yet, the nation chose to inscribe only a select few into the nation's collective memory. Ann Nelson's The Guys (2001), Neil LaBute's The Mercy Seat (2002), and Karen Finley's Make Love (2003) are paradigmatic examples of forming narrative memory in the American theater. The article shows how these dramatic narratives interact with their cultural context. It explores the ways in which these plays might speak to Judith Butler's concern for a proper ethical framing of traumatic memory, one that interlinks the mourning for the vulnerability of the self with an awareness of the vulnerability of others. So far, American theater has shown little interest in working out what Butler has called an “ethics of vulnerability.” It has frequently fallen back on either the celebratory affirmation of nationhood (Nelson) or its sarcastic questioning (LaBute). It is only in Finley's performance piece that we begin to see an attempt to move beyond such unilateral accounts of suffering.
Das Warten auf den Herrensignifikanten oder: Die Verhandlung von Zufall, Zeichen und Notwendigkeit in Thomas Pynchons The Crying of Lot 49 als Kritik des Indizienparadigmas
Authors: Koch Lars
Published: April 2011

Thomas Pynchon's The Crying of Lot 49 (1966), may be read as an implicit exploration of John F. Kennedy's assassination and the investigations of the Warren Commission. By presenting the female protagonist Oedipa Maas as a truth seeker who gradually entangles herself in protoparanoid thinking, the novel discusses the epistemological preconditions of the evidence on which the Warren report is based on. This leads to the question of how the relationship of fact and fiction is filtered through Oedipa's hermeneutics of suspicion.
Von der “(Un)Möglichkeit, sich in die Fremde hineinzuleben”. Kulturelle Assimilation als Desintegration am Beispiel von Ilija Trojanows Roman Der Weltensammler
Authors: Rath Matthias
Published: April 2011

In Der Weltensammler (2006), the policultural German author Ilija Trojanow assumes a critical perspective towards cultural assimilation. Processes of cultural assimilation in heterogeneous social systems lead to conflicting claims of inclusion. The individual can only evade these contradictory claims by adjusting his role and identity to suit different cultural groups. Trojanow's novel exemplifies that identity-stressing transitions risk the disintegration of the self. Enculturation will fail if either the source or the target society culturally defines itself by hedging off presumed aliens. However, Trojanow also shows how an empathic merger into a foreign culture could lead to a new identity, whatever the assimilation pressure and the risk of becoming a castaway.
Chemical modification of lignin assisted by microwave irradiation
Authors: Ouyang Xinping , Lin Zaixiong , Yang Dongjie , Qiu Xueqing
Published: April 2011

Soda lignin was converted into sulfonated lignin by oxidation, hydroxymethylation, and sulfonation assisted by microwave irradiation. Oxidation and hydroxymethylation under these circumstances led to lignins with much higher reactivity toward subsequent sulfonation, and the sulfonation degree could be elevated up to 2.75 mmol g-1. A suitable microwave irradiation time is beneficial to obtain oxidized lignin with small molecular size, but the irradiation time must be selected adequately. Under optimal conditions, the sulfonated lignin exhibits a good dispersive effect to TiO2 suspension. Compared to conventional water bath heating, microwave irradiation not only increases the sulfonation degree of lignin, but also sharply shortens the reaction time.
A Forward Genetic Screen Identifies Mutants Deficient for Mitochondrial Complex I Assembly in Chlamydomonas reinhardtii
Authors: Barbieri M Rosario , Larosa Véronique , Nouet Cécile , Subrahmanian Nitya , Remacle Claire , Hamel Patrice P
Published: April 2011

Mitochondrial complex I is the largest multimeric enzyme of the respiratory chain. The lack of a model system with facile genetics has limited the molecular dissection of complex I assembly. Using Chlamydomonas reinhardtii as an experimental system to screen for complex I defects, we isolated, via forward genetics, amc1–7 nuclear mutants (for assembly of mitochondrial complex I) displaying reduced or no complex I activity. Blue native (BN)-PAGE and immunoblot analyses revealed that amc3 and amc4 accumulate reduced levels of the complex I holoenzyme (950 kDa) while all other amc mutants fail to accumulate a mature complex. In amc1, -2, -5–7, the detection of a 700 kDa subcomplex retaining NADH dehydrogenase activity indicates an arrest in the assembly process. Genetic analyses established that amc5 and amc7 are alleles of the same locus while amc1–4 and amc6 define distinct complementation groups. The locus defined by the amc5 and amc7 alleles corresponds to the NUOB10 gene, encoding PDSW, a subunit of the membrane arm of complex I. This is the first report of a forward genetic screen yielding the isolation of complex I mutants. This work illustrates the potential of using Chlamydomonas as a genetically tractable organism to decipher complex I manufacture.
First report of an endometrial adenoacanthoma in a dog
Authors: Balka Gyula , Szabó Lajos , Jakab Csaba
Published: April 2011

Uterine adenoacanthoma, a subtype of primary endometrial adenocarcinoma, was found in a tissue specimen removed during ovariohysterectomy from an 8-year-old German Shepherd dog. Multifocal, benign squamous metaplastic islands were identified in the parenchyma of the malignant endometrial tumour. The tumour was highly infiltrative but did not metastasise to other organs. Detailed immunohistochemical analyses were carried out in order to characterise the immunophenotype of the tumour.
A Hybrid Actuation System (HYBAS) and Aerospace Applications
Authors: Su Ji , Xu Tian-Bing , Zhang Shujun , Shrout Thomas R. , Zhang Qiming
Published: April 2011

An electroactive polymer-ceramic hybrid actuation system (HYBAS) has been developed at NASA Langley Research Center. The system demonstrates significantly-enhanced electromechanical performance by cooperatively utilizing advantages of a combination of electromechanical responses of an electroative polymer (EAP), and an electroactive ceramic single crystal, PZN-PT single crystal. The electroactive elements are driven by a single power source. Recently, a modification of HYBAS has been made to increase the capability of air driving for synthetic jet devices (SJ) used in aerodynamic control technologies. The dependence of the air driving capability of the modified HYBAS on the configuration of the actuating device has been investigated. For this particular application, the modified HYBAS demonstrated a 50% increase in the volume change in the synthetic jet air chamber, as compared with that of the HYBAS without the modification. The theoretical modeling of the performances of the HYBAS is in good agreement with experimental observation. The consistence between the theoretical modeling and experimental test make the design concept an effective route for the development of high performance actuating devices for many applications. The theoretical modeling, fabrication of the HYBAS and the initial experimental results will be presented and discussed.
Decrease in Resistance of Ceria Oxygen Sensor Induced by 10 mol% Hf and Zr Doping
Authors: Izu Noriya , Shin Woosuck , Matsubara Ichiro , Murayama Norimitsu
Published: April 2011

Resistive type sensors using 10 mol% Hf-doped ceria and 10 mol% Zr-doped ceria, which had a single cubic phase obtained by solid state reaction, were fabricated and their sensing properties were investigated. The resistance and resistivity of the 10 mol% Hf-doped ceria or 10 mol% Zr-doped ceria were smaller than those of non-doped ceria. In the case of the same temperature of solid state reaction, the resistance and resistivity of the 10 mol% Hf-doped ceria were much smaller than those of the 10 mol% Zr-doped ceria. Furthermore, in the case of the same dopant, the resistance and resistivity of the sensor prepared from the solid state reaction at 1773 K were much smaller than those at 1673 K. The sensor using the 10 mol% Hf-doped ceria could be used as an oxygen gas sensor in wide oxygen partial pressure range and could be applicable to a λ sensor and a universal A/F sensor.
Microstructure-Controlled Multilayer PZT Actuators: Effects of Cyclic Actuation on Crystallographic Structure
Authors: Müller Jens , Hooker Stephanie A. , Balzar Davor
Published: April 2011

In this study, multilayered PbTixZr1-xO3(PZT) samples (produced at sintering temperatures in the range of 1175 °C to 1325 °C) were electrically fatigued by long-term exposure (∼106cycles) to electric fields, and the parameters of initial and remnant polarization were estimated. Changes in the crystallographic microstructure as a function of sintering temperature Ts were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) to gain insight on fatigue mechanisms and their prevention. Results showed that domain wall movement was facilitated in samples processed atTSless than 1250 °C, and that such samples were more resistant to electrical fatigue.
Piezopolymer Diaphragm as high performance biosensor platform
Authors: Cheng Z.-Y. , Li Suiqiong , Xu Zhuo , Cheng Z.-Y.
Published: April 2011

Piezopolymer PVDF and P(VDF-TrFE) based diaphragms were fabricated. The diaphragm can be used as a high performance sensor platform for employing in liquid. The microelectronic process for fabricating microdiaphragm and its array is established. The performance of the PVDF based diaphragm in air and liquid was tested. It is found that the diaphragm works well in liquid.
Modelling of Polypyrrole Actuators
Authors: Samani Mehrdad Bahrami , Whitten Philip G. , Spinks Geoffrey M. , Cook Christopher D.
Published: April 2011

Conducting polymers (CP) are a promising area in the field of micro actuators, and have potential applications in micro robotics. Their properties are modelled as having an electro-chemical active component and a passive viscoelastic component. Methods exist to model the passive component as a configuration of springs and dashpots and the electro-active effects as a strain generator. Typically, the strain is assumed to be proportional to the charge transferred, and the two components are assumed to be independent. We show that there is a significant interaction between the two components for polypyrrole actuators, by observing the dynamic elastic modulus whilst varying the electric potential. The elastic modulus was measured in-situ by applying a high frequency rectangular isotonic stress input and recording the corresponding strain output. Two separate potential control inputs, vs. a reference electrode, were used. In the first experiment, a triangular voltage signal with variable frequency was applied to the PPy helix tube actuator and in the second experiment; a step voltage signal was applied to the actuator. The value of total real modulus was calculated during both experiments to evaluate the effect of actuation on the mechanical properties of PPy actuator. The performance of the mentioned method was confirmed by comparing its results to that of a sinusoidal stress input during a temperature ramp through the glass transition of polyethylene terephthalate (PET). We show that polypyrrole actuators show a complex change in stiffness with contractile state, which mimic skeletal muscle [1].
High Conductivity Ionic Liquid- Nafion Mat Composites for High Speed Ionic Polymer Transducers
Authors: Akle Barbar , Leo Donald J. , Nah Changwoon , Kader Abdul M.
Published: April 2011

Ionomeric polymer transducers consist of an ion-exchange membrane plated with conductive metal layers on the outer surfaces. Such materials are known to generate large bending strain (> 9% is possible) at low applied voltages (typically less than 5 V). The main disadvantage of ionomer–ionic liquid transducers is the slow speed of response. The speed of response in such actuators has been correlated to the ionic liquid content and the conductivity of the membrane. To increase the conductivity of the transducers a Nafion™ mat is hydrated with 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMI-Tf) ionic liquids and high surface area RuO2 electrodes are attached using the Direct Assembly Process (DAP). The Nafion™ mat is prepared from homogenous solution electrospinning. The solution is prepared by mixing 1 wt % of polyethylene oxide solution in methanol (PEO, Mol. wt 3×106) to 5 wt % Nafion 1100 solution.. The syringe needle is connected to a 15kV power supply and is placed 15cm away from the collecting drum. The measured conductivities of water hydrated Nafion electro-spun fibers are 16.8 mS/cm, which are lower than the nominal 110 mS/cm that of H+ Nafion membranes. The uptake is measured to be around 250 %wt compared to 58 %wt obtained in Nafion films. The ionic conductivity of 110 %wt swollen ionic liquids-Nafion mat composite is computed to be 0.9 mS/cm compared to 0.3 mS/cm in ionic liquid-Nafion membrane composite. The speed of response in actuators with an ionic liquid- Nafion™ mat is 1.34 %/s compared to 0.88 %/s for that in ionic liquid Nafion™ film transducers.
Space Charge Modelling in Solid Dielectrics under High Electric Field Based on Double Charge Injection Model
Authors: Chen George , Loi Su Han
Published: April 2011

Present study aims to develop a clear insight on factors that influence space charge dynamics in solid dielectrics through a numerical simulation. The model used for the simulation is proposed by Alison and Hill [1] which describes charge dynamics as a result of bipolar transport with single level trapping. In this model, a constant mobility and no detrapping have been assumed. The simulation results show that carrier mobility, trapping coefficient and Schottky barrier have a significant effect on the space charge dynamics. Many features of space charge profiles observed by experiments have been revealed in despite of over simplistic model. More importantly, the simulation allows us to study the role of each individual parameter in the formation of space charge in solid dielectrics, so that the experimental results can be better understood.
The growth of epitaxial uranium oxide observed by micro-Raman spectroscopy
Authors: Caculitan Niña , Siekhaus Wigbert J.
Published: April 2011

Raman spectroscopy can be performed with micrometer resolution and can thus be used to determine the dependence of oxide thickness on the substrate’s grain structure or local impurity inclusions. The Raman signal amplitude emitted from an epitaxial uranium oxide layer as a function of oxide thickness has been modeled for light of 632.8 nm wavelength incident on the oxide and reflected from the uranium substrate using the optical properties determined by spectrophotometry. The model shows that the Raman signal increases with oxide thickness and saturates at about 150 nm thickness. The model was compared with the measured Raman signal amplitude of an epitaxial uranium oxide layer growing in air with a known time dependence of oxide growth.
Murataite Ceramics Doped with Lanthanides and Uranium
Authors: Stefanovsky Sergey , Yudintsev S.V. , Nikonov B.S. , Stefanovsky O.I.
Published: April 2011

Phase composition of the murataite-based ceramics containing 10 wt.% of mixed oxides simulating rare earth/actinide (REE/An) and actinide (An) fractions of high level waste (HLW) was studied. The ceramics were prepared by melting of oxide mixtures in Pt ampoules in air at ∼1500 °C. Ceramics with REE/An and An fractions surrogates are composed of predominant murataite-type phases and minor extra phases: perovskite and crichtonite. Three murataite-related phases with five- (5C), eight- (8C), and three-fold (3C) elementary fluorite unit cell are present in these ceramics. These phases form core, intermediate zone, and rim of the murataite grains, respectively. They are predominant host phases for the rare earth elements and uranium whose concentrations are reduced in a row: M-5C>M-8C>M-3C. Appreciate fraction of Ce, Nd, and Pu may enter the perovskite phase. In the An-Gd ceramic perovskite and murataite were found to be predominant and secondary in abundance phases respectively.
Structural Investigation of δ-stabilized Plutonium Alloys Under Pressure
Authors: Faure Philippe , Klosek Vincent , Genestier Claudine , Baclet Nathalie , Heathman Steve , Normile Peter , Haire Richard
Published: April 2011

The mechanism responsible for the stability of the delta-phase in plutonium alloys remains poorly understood despite previous extensive studies. In the present experiments, three alloys (Pu-8at%Am, Pu-15at%Am and Pu-2at%Ga) were studied under pressure by X-ray diffraction in diamond anvil cells and revealed i) a pressure-induced softening in the compressibility of the delta-phase and ii) the presence of an intermediate γ’-phase across the δ → α’ phase transition. The softening, an anomalous behaviour, is shown to be coherent with other known unusual properties found for these alloys like NTE (Negative Thermal Expansion). Furthermore, it has been observed that the cell volume for the α’-phase formed under pressure depends on the rate of the pressure increase. This behaviour may be related to the diffusion of solute atoms to specific sites within the α’-phase unit cell. Such diffusion may also explain the α’-phase unit cell’s volume shrinkage versus time in a Pu-2at%Ga sample kept at a constant pressure.

These XRD results, obtained under pressure, may be used to test first-principle calculations or other general modelling which aim at predicting the solute’s diffusion and/or self-irradiation effects in plutonium alloys.
Structural investigation of Neptunium(IV) in toxicological processes
Authors: Den Auwer Christophe , Moisy Philippe , Guillaumont Dominique , Vidaud Claude , Funke Harald , Hennig Christoph
Published: April 2011

General understanding of intramolecular interactions engaged in molecular actinide species, in other words physical chemical mechanisms that drive the affinity of chelating ligands for actinide cations still needs to be deepened. In this field, X ray Absorption Spectroscopy has been extensively used as a structural and electronic metal cation probe. Combination with more traditional spectroscopic techniques as spectrophotometry is an ideal tool for the understanding of the chelation mechanism. Metallobiomolecules are considered as elaborate inorganic complexes with well-designed metal active sites. Although the various interaction processes between essential cations to biology and proteins are widely studied, focus on the actinide family is more seldom. Actinide impact to biological cycles has been motivated by risk assessments related to the wide use of nuclear fuel sources and industrial or military applications. In particular, the interactions of these cations with the biologically active complexation sites are only partially understood.
Combinatorial Fabrication and Screening of Organic Light-Emitting Device Arrays
Authors: Shinar Joseph , Shinar Ruth
Published: April 2011

Studies of combinatorial fabrication and screening of organic light-emitting devices (OLEDs) are reviewed. These studies include screening of luminescent materials, electron and hole transport layers, lower-gap emitting guest dopants in small molecular emitters, and electronically doped polymeric anodes. The review focuses on screening of 2-dimensional (2-d) small molecular UV/violet arrays, 1-d blue-to-red arrays, and 1-d intense white OLED libraries, and briefly describes arrays fabricated to study Förster energy transfer in guest-host OLEDs. It demonstrates that combinatorial fabrication of OLEDs has become a powerful tool for screening OLED materials and configurations, and for studying their basic properties.
Knowledge Discovery Applications in High-Throughput Polymer Characterization
Authors: Su Jing , Zapata Pedro , Meredith Carson
Published: April 2011

The use of combinatorial libraries for screening cell-material interactions presents a significant need for robust informatics methods capable of extracting knowledge from large, combinatorial datasets. We describe the development of local quantitative metrics based on distributions of other cells and microstructures about each individual cell. The local metrics are shown to be superior to global, summary statistics in detecting sensitive effects of surface microstructure on proliferation of MC3T3-E1 osteoblasts.
Wireless sensor array system for combinatorial screening of sensor materials
Authors: Morris William , Potyrailo Radislav
Published: April 2011

Screening of materials arrays for their viscoelastic, gas-sorbing, and electrical properties is important for a variety of practical applications ranging from sensor to protective coatings. Complex impedance analysis of the materials arrays is an attractive approach to analyze these materials properties. We developed a wireless proximity sensor array system for combinatorial screening of these types of materials and demonstrated its applicability for sensor materials. In the developed system, sensor materials are applied onto an array of resonators and arranged for performance testing in a test chamber. Each resonator is coupled to a receiver antenna. An array of these antennas is read with a single scanning transmitter antenna or an array of transmitter antennas. Such high-throughput screening approach of sensor materials permits their evaluation in complex environments where additional wiring is not desirable or adds a prohibitively complex design.
Global Optimization of Atomic Cluster Structures Using Parallel Genetic Algorithms
Authors: Oña Ofelia , Bazterra Victor E. , Caputo María C. , Ferraro Marta B. , Facelli Julio
Published: April 2011

The study of the structure and physical properties of atomic clusters is an extremely active area of research due to their importance, both in fundamental science and in applied technology. For medium size atomic clusters most of the structures reported today have been obtained by local optimizations of plausible structures using DFT (Density Functional Theory) methods and/or by global optimizations in which much more approximate methods are used to calculate the cluster’s energetics. Our previous work shows that these approaches can not be reliably used to study atomic cluster structures and that approaches based on global optimization schemes are needed. In this paper, we report the implementation and application of a parallel Genetic Algorithm (GA) to predict the structure of medium size atomic clusters.