bluuebunny/crossref_metadata_2025 huggingface dataset:
Abdominal wall and labial edema presenting in a girl with Henoch-Schönlein purpura: a case report
Authors: Hiram-Karasmanis Rania , Smith Ronald Garth , Radina Maria , Soboleski Donald Allen
Published: March 2010

Introduction

Henoch-Schönlein purpura is a common immunoglobulin A-mediated vasculitic syndrome in children, characterized by purpuric rash, arthritis and abdominal pain. Renal involvement, manifested by the presence of hematuria and/or proteinuria, is also frequently seen. In most cases, patients with this disease achieve complete recovery, but some progress to renal impairment. Gastro-intestinal manifestations are present in two-thirds of affected patients and range from vomiting, diarrhea, and peri-umbilical pain to serious complications such as intussusception and gastrointestinal hemorrhage.

Case presentation

We report the case of a 7-year-old Caucasian girl who presented with abdominal pain, labial swelling, and a large abdominal ecchymosis two weeks after having been diagnosed with Henoch-Schönlein purpura. A computed tomography scan revealed abdominal wall edema extending to the groin, without any intra-abdominal pathology. She was successfully treated with intravenous steroids.

Conclusion

Circumferential anterior abdominal wall edema and labial edema have never been reported previously, to the best of our knowledge, as a complication of Henoch-Schönlein purpura. These findings further contribute to the wide spectrum of manifestations of this disorder in the literature, aiding in its recognition and management.
Trastuzumab Sensitizes Ovarian Cancer Cells to EGFR-targeted Therapeutics
Authors: Wilken Jason A , Webster Kristy T , Maihle Nita J
Published: March 2010

Background

Early studies have demonstrated comparable levels of HER2/ErbB2 expression in both breast and ovarian cancer. Trastuzumab (Herceptin), a therapeutic monoclonal antibody directed against HER2, is FDA-approved for the treatment of both early and late stage breast cancer. However, clinical studies of trastuzumab in epithelial ovarian cancer (EOC) patients have not met the same level of success. Surprisingly, however, no reports have examined either the basis for primary trastuzumab resistance in ovarian cancer or potential ways of salvaging trastuzumab as a potential ovarian cancer therapeutic.

Methods

An in vitro model of primary trastuzumab-resistant ovarian cancer was created by long-term culture of HER2-positive ovarian carcinoma-derived cell lines with trastuzumab. Trastuzumab treated vs. untreated parental cells were compared for HER receptor expression, trastuzumab sensitivity, and sensitivity to other HER-targeted therapeutics.

Results

In contrast to widely held assumptions, here we show that ovarian cancer cells that are not growth inhibited by trastuzumab are still responsive to trastuzumab. Specifically, we show that responsiveness to alternative HER-targeted inhibitors, such as gefitinib and cetuximab, is dramatically potentiated by long-term trastuzumab treatment of ovarian cancer cells. HER2-positive ovarian carcinoma-derived cells are, therefore, not "unresponsive" to trastuzumab as previously assumed, even when they not growth inhibited by this drug.

Conclusions

Given the recent success of EGFR-targeted therapeutics for the treatment of other solid tumors, and the well-established safety profile of trastuzumab, results presented here provide a rationale for re-evaluation of trastuzumab as an experimental ovarian cancer therapeutic, either in concert with, or perhaps as a "primer" for EGFR-targeted therapeutics.
Cost of acute renal replacement therapy in the intensive care unit: results from The Beginning and Ending Supportive Therapy for the Kidney (BEST Kidney) Study
Authors: Srisawat Nattachai , Lawsin Loredo , Uchino Shigehiko , Bellomo Rinaldo , Kellum John A ,   the BEST Kidney Investigators
Published: March 2010

Introduction

Severe acute kidney injury (AKI) can be treated with either continuous renal replacement therapy (CRRT) or intermittent renal replacement therapy (IRRT). Limited evidence from existing studies does not support an outcome advantage of one modality versus the other, and most centers around the word use both modalities according to patient needs. However, cost estimates involve multiple factors that may not be generalizable to other sites, and, to date, only single-center cost studies have been performed. The aim of this study was to estimate the cost difference between CRRT and IRRT in the intensive care unit (ICU).

Methods

We performed a post hoc analysis of a prospective observational study among 53 centers from 23 countries, from September 2000 to December 2001. We estimated costs based on staffing, as well as dialysate and replacement fluid, anticoagulation and extracorporeal circuit.

Results

We found that the theoretic range of costs were from $3,629.80/day more with CRRT to $378.60/day more with IRRT. The median difference in cost between CRRT and IRRT was $289.60 (IQR 830.8-116.8) per day (greater with CRRT). Costs also varied greatly by region. Reducing replacement fluid volumes in CRRT to ≤ 25 ml/min (approximately 25 ml/kg/hr) would result in $67.20/day (23.2%) mean savings.

Conclusions

Cost considerations with RRT are important and vary substantially among centers. We identified the relative impact of four cost domains (nurse staffing, fluid, anticoagulation, and extracorporeal circuit) on overall cost differences, and hospitals can look to these areas to reduce costs associated with RRT.
Which Patients With Cancer Die at Home? A Study of Six European Countries Using Death Certificate Data
Authors: Cohen Joachim , Houttekier Dirk , Onwuteaka-Philipsen Bregje , Miccinesi Guido , Addington-Hall Julia , Kaasa Stein , Bilsen Johan , Deliens Luc
Published: March 2010

Purpose

This study examines the proportion of cancer deaths occurring at home in six European countries in relation to illness and to demographic and health care factors.

Methods

Death certificate data of all cancer-related deaths in 2002 in Italy and 2003 in Belgium, the Netherlands, Norway, England, and Wales (N = 238,216) were linked with regional health care and area statistics. Multivariate binomial logistic regressions were performed to examine factors associated with dying at home.

Results

The percentage of all cancer deaths occurring at home was 12.8 in Norway, 22.1 in England, 22.7 in Wales, 27.9 in Belgium, 35.8 in Italy, and 45.4 in the Netherlands. Having solid cancers and being married increased the chances of dying at home in all countries. Being older and being a woman decreased the chances of dying at home, except in Italy where the opposite was the case. A higher educational attainment was associated with better chances of dying at home in Belgium, Italy, and Norway (countries where information on educational attainment was available). Better chances of dying at home were also associated with living in less urbanized areas in all countries but England. The number of hospital and care home beds seemed not to be universally strong predictors of dying at home.

Conclusion

There are large country differences in the proportion of patients with cancer dying at home, and these seem influenced by country-specific cultural, social, and health care factors. Alongside cross-national differences, country-specific aspects need to be considered in the development of policy strategies facilitating home death.
Association Between Mammographic Density and Age-Related Lobular Involution of the Breast
Authors: Ghosh Karthik , Hartmann Lynn C. , Reynolds Carol , Visscher Daniel W. , Brandt Kathleen R. , Vierkant Robert A. , Scott Christopher G. , Radisky Derek C. , Sellers Thomas A. , Pankratz V. Shane , Vachon Celine M.
Published: March 2010

Purpose

Mammographic density and lobular involution are both significant risk factors for breast cancer, but whether these reflect the same biology is unknown. We examined the involution and density association in a large benign breast disease (BBD) cohort.

Patients and Methods

Women in the Mayo Clinic BBD cohort who had a mammogram within 6 months of BBD diagnosis were eligible. The proportion of normal lobules that were involuted was categorized by an expert pathologist as no (0%), partial (1% to 74%), or complete involution (≥ 75%). Mammographic density was estimated as the four-category parenchymal pattern. Statistical analyses adjusted for potential confounders and evaluated modification by parity and age. We corroborated findings in a sample of women with BBD from the Mayo Mammography Health Study (MMHS) with quantitative percent density (PD) and absolute dense and nondense area estimates.

Results

Women in the Mayo BBD cohort (n = 2,667) with no (odds ratio, 1.7; 95% CI, 1.2 to 2.3) or partial (odds ratio, 1.3; 95% CI, 1.0 to 1.6) involution had greater odds of high density (DY pattern) than those with complete involution (P trend < .01). There was no evidence for effect modification by age or parity. Among 317 women with BBD in the MMHS study, there was an inverse association between involution and PD (mean PD, 22.4%, 21.6%, 17.2%, for no, partial, and complete, respectively; P trend = .04) and a strong positive association of involution with nondense area (P trend < .01). No association was seen between involution and dense area (P trend = .56).

Conclusion

We present evidence of an inverse association between involution and mammographic density.
Transition of Care for Young Adult Survivors of Childhood and Adolescent Cancer: Rationale and Approaches
Authors: Freyer David R.
Published: March 2010

Purpose

Young adult survivors of childhood and adolescent cancer are an ever-growing population of patients, many of whom remain at lifelong risk for potentially serious complications of their cancer therapy. Yet research shows that many of these older survivors have deficient health-related knowledge and are not engaging in recommended health promotion and screening practices that could improve their long-term outcomes. The purpose of this review is to address these disparities by discussing how formal transition of care from pediatric to adult-focused survivorship services may help meet the unique medical, developmental, and psychosocial challenges of these young adults.

Design

Literature review and discussion.

Results

This article summarizes current research documenting the medical needs of young adult survivors, their suboptimal compliance with recommended follow-up, and the rationale, essential functions, current models, and innovative approaches for transition of follow-up care.

Conclusion

Systematic health care transition constitutes the standard of care for young adult survivors of childhood cancer. In developing a transitional care program, it is necessary to consider the scope of services to be provided, available resources, and other local exigencies that help determine the optimal model for use. Additional research is needed to improve health services delivery to this population. Effective advocacy is needed, particularly in the United States, to ensure the availability of uninterrupted health insurance coverage for survivorship services in young adulthood.
Acting Inca: The Parameters of National Belonging in Early Twentieth-Century Bolivia
Authors: Kuenzli E. Gabrielle
Published: March 2010

This article focuses on the connection between Aymara indigenous communities, Liberal intellectuals, and the nation-building process in late nineteenth and early twentieth-century Bolivia. The Liberal intellectuals’ designs of nation in early twentieth-century Bolivia were shaped in part by the actions and political initiatives of the very “Indians” the intellectuals sought to categorize, define, and contain. Somewhat paradoxically, the national intellectuals and the local Aymara elite unwittingly collaborated in the construction of a preferred Indian identity, the Inca, to create a noble and progressive past for the nation and to marginalize the undesirable, non-elite Aymara indigenous population in the wake of the 1899 Civil War between Liberals and Conservatives. The process of narrating the native past was of importance to national intellectuals as well as to native peoples. Several types of sources inform these late nineteenth and early twentieth-century discourses of nation building, including judicial court cases, archival documentation, and theatrical performance. The narrative of the indigenous past and the role of the actual Indian population within the Bolivian nation in the early twentieth century was a site of negotiation located at the center of national politics, establishing the foundation for a nation that would maintain differentiated constructions of Indian identity at its core.
Have I Been Destroyed? Answering to Authority and the Politics of the Father
Authors: Ronell Avital
Published: March 2010

Exploring the cobelonging of the philosophical and the political, this essay reflects on the question of authority. Plato more or less invented authority when he sought to establish a reliable force that would intercede between power and persuasion. Rhetorical persuasion had failed philosophy when it did nothing to prevent the state's murder of Socrates. Philosophy was too puny to fight the power. Authority and its cognates gave Plato the arsenal he needed to upgrade the philosophical stance and give it an antiballistic shield. Hannah Arendt and Alexandre Kojève show concern over the disappearance of authority and its implicit calamity. Philippe Lacoue-Labarthe, Jean-Luc Nancy, and Samuel Weber offer a neighboring perspective on panic and authority.
The Fable of the Stork and Other False Sexual Theories
Authors: Copjec Joan
Published: March 2010

differences began publishing in the midst of a climate change in feminist relations to psychoanalysis and the question of sexual difference. As many scholars began to pay theoretical attention to other kinds of difference as well as sexual differences, some argued that this obligation entailed not just a widening of focus but a critique of psychoanalysis as ahistorical and an abandonment of the notion of sexual difference in favor of gender. Gender, Copjec argues in this paper, is a neutered term; it eliminates sex. It is time, this essay proposes, to provide an ontological reflection on sex and sexuality.
The Practice of Feminist Theory
Authors: Grosz Elizabeth
Published: March 2010

This paper addresses the question of what a concept is and how concepts are relevant to the work of feminist politics. It argues, using the work of Deleuze and Guattari, that the creation of concepts is the production of an event that addresses the unpredictability of events. A concept provides an event with an incorporeal lining, a virtual force that enables the event to give way to new and unpredictable effects. Feminist theory has produced a profound concept that has not yet been adequately understood: the concept of sexual difference, which has been elaborated in most detail in the writings of Luce Irigaray. This article explores how the concept of sexual difference, while addressing the event of the emergence of humanity in two distinct forms, produces the possibility of a new kind of politics and new kinds of social relations that do not reduce sexual difference to its patriarchal expressions.
Laser-induced microstructural modification for corrosion protection
Authors: Liu Z , Liu H , Viejo F , Aburas Z , Rakhes M
Published: March 2010

Laser surface modification of materials by melting and annealing has been the subject of considerable interest as a means of enhancing the corrosion performance of metallic alloys. Microstructural modification without changing surface chemical composition, in terms of homogenization/refinement of microstructures, dissolution/re-distribution of intermetallic particles, and extended solid solubility, resulting from rapid rates of cooling, provides the basis for property enhancement. This paper reviews authors’ work on laser surface melting (LSM) and laser annealing (LA) for the purpose of improved corrosion performance. Microstructural evolution and corrosion performance in a range of metallic alloys, followed by different treatments with different types of lasers, are presented. For LSM of aerospace aluminium alloys, the corrosion mechanisms of the laser-melted alloys have been discussed in the consideration of electrochemical characteristics of intermetallic particles with respect to the aluminium matrix and cooling rates leading to different degrees of refinement/removal of intermetallic particles. For LA of amorphous electroless Ni-W-P plating, porosity formation and grain growth and microstrain/residual stress resulting from laser-induced nanocrystallization are the major concerns, affecting corrosion performance. In addition, potential applications of LSM as pre-treatment method prior to conventional anodizing or post-treatment of thermal sprayed coatings have been demonstrated.
What Powers for the Federal Reserve?
Authors: Feldstein Martin
Published: March 2010

In this essay, I explain my reasons for the following policy recommendations: (1) The Fed should continue to manage monetary policy as it has in the past, should act as the nation's lender of last resort, should fully supervise the large bank holding companies and their subsidiary banks, and should be given resolution authority over the institutions that it supervises. (2) While a council of supervisors and regulators can play a useful role in dealing with macro prudential risks, it should not replace the central role of the Federal Reserve. (3) The virtually unlimited lending powers that the Fed has recently exercised in creating credit and helping individual institutions should be restricted in duration and subjected to formal Treasury approval backed by Congressional preauthorization of funds. (4) The Fed's capital rules for commercial banks need to be strengthened by replacing the existing risk-based capital approach with a broader definition of risk and the introduction of contingent capital. (5) Subjecting mortgage lending to a broader range of Federal Reserve regulations and allowing the Fed to deal with nonbank creators of mortgage products would be better than the creation of a new consumer financial protection organization. (JEL E52, E58, G21, G28)
Differential regulation of microRNA stability
Authors: Bail Sophie , Swerdel Mavis , Liu Hudan , Jiao Xinfu , Goff Loyal A. , Hart Ronald P. , Kiledjian Megerditch
Published: March 2010

MicroRNAs (miRNAs) are endogenous single-stranded RNA molecules of about 21 nucleotides in length that are fundamental post-transcriptional regulators of gene expression. Although the transcriptional and processing events involved in the generation of miRNAs have been extensively studied, very little is known pertaining to components that regulate the stability of individual miRNAs. All RNAs have distinct inherent half-lives that dictate their level of accumulation and miRNAs would be expected to follow a similar principle. Here we demonstrate that although most miRNA appear to be stable, like mRNAs, miRNAs possess differential stability in human cells. In particular, we found that miR-382, a miRNA that contributes to HIV-1 provirus latency, is unstable in cells. To determine the region of miR-382 responsible for its rapid decay, we developed a cell-free system that recapitulated the observed cell-based-regulated miR-382 turnover. The system utilizes in vitro-processed mature miRNA derived from pre-miRNA and follows the decay of the processed miRNA. Using this system, we demonstrate that instability of miR-382 is driven by sequences outside its seed region and required the 3′ terminal seven nucleotides where mutations in this region increased the stability of the RNA. Moreover, the exosome 3′–5′ exoribonuclease complex was identified as the primary nuclease involved in miR-382 decay with a more modest contribution by the Xrn1 and no detectable contribution by Xrn2. These studies provide evidence for an miRNA element essential for rapid miRNA decay and implicate the exosome in this process. The development of a biochemically amendable system to analyze the mechanism of differential miRNA stability provides an important step in efforts to regulate gene expression by modulating miRNA stability.
Hypermutation induced by APOBEC-1 overexpression can be eliminated
Authors: Chen Zhigang , Eggerman Thomas L. , Bocharov Alexander V. , Baranova Irina N. , Vishnyakova Tatyana G. , Csako Gyorgy , Patterson Amy P.
Published: March 2010

APOBEC-1 overexpression in liver has been shown to effectively reduce apoB-100 levels. However, nonspecific hypermutation and liver tumor formation potentially related to hypermutation in transgenic animals compromise its potential use for gene therapy. In studying apoB mRNA editing regulation, we found that the core editing auxiliary factor ACF dose-dependently increases APOBEC-1 nonspecific hypermutation and specific editing with variable site sensitivity. Overexpression of APOBEC-1 together with ACF in human hepatic HepG2 cells hypermutated apoB mRNAs 20%–65% at sites 6639, 6648, 6655, 6762, 6802, and 6845, in addition to the normal 90% editing at 6666. The hypermutation activity of APOBEC-1 was decreased to background levels by a single point APOBEC-1 mutation of P29F or E181Q, while 50% of wild-type control editing at the normal site was retained. The hypermutations on both apoB and novel APOBEC-1 target 1 (NAT1) mRNA were also decreased to background levels with P29F and E181Q mutants in rat liver primary culture cells. The loss of hypermutation with the mutants was associated with significantly decreased APOBEC-1/ACF interaction. These data suggest that nonspecific hypermutation induced by overexpressing APOBEC-1 can be virtually eliminated by site-specific mutation, while maintaining specific editing activity at the normal site, reopening the potential use of APOBEC-1 gene therapy for hyperlipidemia.
Selection of RNA aptamers imported into yeast and human mitochondria
Authors: Kolesnikova Olga , Kazakova Helena , Comte Caroline , Steinberg Sergey , Kamenski Piotr , Martin Robert P. , Tarassov Ivan , Entelis Nina
Published: March 2010

In the yeast Saccharomyces cerevisiae, nuclear DNA-encoded is partially imported into mitochondria. We previously found that the synthetic transcripts of yeast tRNALys and a number of their mutant versions could be specifically internalized by isolated yeast and human mitochondria. The mitochondrial targeting of tRNALys in yeast was shown to depend on the cytosolic precursor of mitochondrial lysyl-tRNA synthetase and the glycolytic enzyme enolase. Here we applied the approach of in vitro selection (SELEX) to broaden the spectrum of importable tRNA-derived molecules. We found that RNAs selected for their import into isolated yeast mitochondria have lost the potential to acquire a classical tRNA-shape. Analysis of conformational rearrangements in the importable RNAs by in-gel fluorescence resonance energy transfer (FRET) approach permitted us to suggest that protein factor binding and subsequent import require formation of an alternative structure, different from a classic L-form tRNA model. We show that in the complex with targeting protein factor, enolase 2, tRK1 adopts a particular conformation characterized by bringing together the 3′-end and the TΨC loop. This is a first evidence for implication of RNA secondary structure rearrangement in the mechanism of mitochondrial import selectivity. Based on these data, a set of small RNA molecules with significantly improved efficiency of import into yeast and human mitochondria was constructed, opening the possibility of creating a new mitochondrial vector system able to target therapeutic oligoribonucleotides into deficient human mitochondria.
Role of the C-terminal tail of SmpB in the early stage of trans-translation
Authors: Kurita Daisuke , Muto Akira , Himeno Hyouta
Published: March 2010

Trans-translation relieves a stalled translation on the bacterial ribosome by transfer-messenger RNA (tmRNA) with the help of SmpB, an essential cofactor of tmRNA. Here, we examined the role of the unstructured C-terminal tail of SmpB using an in vitro trans-translation system. It was found that truncation of the C-terminal tail or substitution of tryptophan residue at 147 in the middle of the C-terminal tail affected the activity in the early stage of trans-translation. Our investigations also revealed that the C-terminal tail is not required for the events until GTP is hydrolyzed by EF-Tu in complex with tmRNA-SmpB. A synthetic peptide corresponding to the C-terminal tail of SmpB inhibited peptidyl-transfer of alanyl-tmRNA and A-site binding of SmpB, but not GTP hydrolysis. These results suggest that the C-terminal tail has a role in the step of accommodation of alanyl-tmRNA-SmpB into the A-site. Directed hydroxyl radical probing indicated that tryptophan residue at 147 is located just downstream of the decoding center in the mRNA path when SmpB is in the A-site.
The presence of high-molecular-weight viral RNAs interferes with the detection of viral small RNAs
Authors: Smith Neil A. , Eamens Andrew L. , Wang Ming-Bo
Published: March 2010

Viral small interfering RNA (siRNA) accumulation in plants is reported to exhibit a strong strand polarity bias, with plus (+) strand siRNAs dominating over minus (−) strand populations. This is of particular interest, as siRNAs processed from double-stranded RNA would be expected to accumulate equivalent amounts of both species. Here, we show that, as reported, (−) strand viral siRNAs are detected at much lower levels than (+) strand-derived species using standard Northern hybridization approaches. However, when total RNA is spiked with in vitro-transcribed antisense viral genomic RNA, (−) strand viral siRNAs are detected at increased levels equivalent to those of (+) strand siRNA. Our results suggest that (+) and (−) strand viral siRNAs accumulate to equivalent levels; however, a proportion of the (−) strand siRNAs are sequestered from the total detectable small RNA population during gel electrophoresis by hybridizing to the high-molecular-weight sense strand viral genomic RNA. Our findings provide a plausible explanation for the observed strand bias of viral siRNA accumulation, and could have wider implications in the analysis of both viral and nonviral small RNA accumulation.
Corporeal awareness and proprioceptive sense of the phantom
Authors: Giummarra Melita J. , Georgiou‐Karistianis Nellie. , Nicholls Michael E. R. , Gibson Stephen J. , Chou Michael. , Bradshaw John L.
Published: March 2010

Phantom limb perception almost invariably follows limb amputation, and can be characterized by various corporeal and proprioceptive qualities. We report a study of 283 amputees, which administered a structured questionnaire to systematically determine the relative frequency and nature of various bodily aspects of phantom limb perception. These include the size, shape, posture, and telescoping of the phantom; exteroceptive sensations of itch, touch, pressure, vibration, temperature, and ‘electric’ sensations; and prosthesis embodiment. Phantom limbs were generally found to be characterized by properties that parallel those of the intact body, although with anatomically impossible configurations sometimes being perceived. We suggest that both the internal limb image and limb schemata play a significant role in the continued perception of phantom limbs.
Cross‐cultural validation of the Cardiac Depression Scale in Iran
Authors: Gholizadeh Leila. , Salamonson Yenna. , Davidson Patricia M. , Parvan Kobra. , Frost Steven A. , Chang Sungwon. , Hare David L.
Published: March 2010

Background. The Cardiac Depression Scale (CDS) is a disease‐specific instrument for measuring depression in cardiac patients. This study was designed to validate the CDS in an Iranian population.

Methods. Translation and back‐translation of the 26‐item CDS scale was performed using recommended procedures. The Iranian translation of the CDS (I‐CDS) was administered to 261 individuals in Iran, concurrently with the Beck Depression Inventory. The factor structure of the I‐CDS was examined using exploratory factor analysis procedures to enable comparison with previous psychometric evaluation of the CDS. Receiver operating characteristic curves were used to examine the ability of the I‐CDS to discriminate between categories of depression.

Results. First‐order exploratory factor analysis uncovered two robust factors, consistent with the second‐order dimensions originally reported by the developers of this instrument. Cronbach's alpha was .88 for the total 26‐item I‐CDS, indicating satisfactory internal consistency of the I‐CDS. Intercorrelation between the total scores for the I‐CDS and BDI was .62 (p<.001). For the I‐CDS cut‐off of 90, the sensitivity was 85%, and specificity was 61% with a computed area under the curve (AUC) of 0.81 (95% CI, 0.76–0.87). For the I‐CDS cut‐off of 100, the sensitivity was 81%, and specificity was 63% with a computed AUC of 0.81 (95% CI, 0.76–0.87).

Conclusion. This validation study of the Iranian version of the CDS demonstrated that it is an acceptable, reliable, and valid measure of depression in people with heart disease.
Radical-substituted dihydrophenazine radical cation salts: Molecular packing structure and bulk magnetic property
Authors: Masuda Yuki , Takeda Hirotaka , Kuratsu Masato , Suzuki Shuichi , Kozaki Masatoshi , Shiomi Daisuke , Sato Kazunobu , Takui Takeji , Okada Keiji
Published: March 2010

Radical-substituted radical cation salts are exotic species that are potentially applicable as spin building blocks for molecular magnets. We recently found that these species, which are derived from a diphenyldihydrophenazine (DPP) framework, are stable under aerated conditions at room temperature. Of these species, nitronyl nitroxide (NN•)-substituted DPP•+ tetrachloroferrate (NNDPP••+·FeCl4–) showed antiferromagnetic interaction at low temperature (<150 K), whereas the tetrabromoferrate salt NNDPP••+·FeBr4– exhibited a magnetic phase transition at 6.7 K to produce a bulk ferrimagnet. Both salts had very similar molecular structures. The difference in the magnetic properties was ascribed to the difference in molecular packing structures. A significant difference in these two salts was observed at the (NNDPP••+)–(NNDPP••+) intermolecular contact, including the oxygen atom of the nitroxide moiety; NNDPP••+·FeCl4– had a serious antiferromagnetic O–O (nitroxide oxygen, 3.02 Å) intermolecular contact, whereas NNDPP••+·FeBr4– had a ferromagnetic O–HC (2.53 Å) intermolecular contact.
Effect of Sialylated O-Glycans in Pro–Brain Natriuretic Peptide Stability
Authors: Jiang Jingjing , Pristera Nicole , Wang Wei , Zhang Xiumei , Wu Qingyu
Published: March 2010

Background: Atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP) are important in regulating a variety of cardiovascular and cellular functions. In cells, these peptides are made as proforms that are converted to mature forms. BNP and its related peptides are biomarkers for the diagnosis of heart failure. In this study, we examined glycosylation in pro-ANP, pro-BNP, and pro-CNP, which may alter their biochemical and metabolic properties.

Methods: Human pro-ANP, pro-BNP, and pro-CNP were expressed in HEK 293 cells and murine HL-1 cardiomyocytes and analyzed by immunoprecipitation and Western blotting. We used deglycosylation enzymes to determine the carbohydrate content on these peptides and examined the effects of inhibiting O-glycosylation on cellular expression and stability of the peptides.

Results: In HEK 293 and HL-1 cells, pro-BNP, but not pro-ANP and pro-CNP, from the culture medium had a greater molecular mass than that from cell lysate. Digestion with PNGase F, O-glycosidase, and sialidase A indicated that pro-BNP contained O-glycans but not N-glycans. The O-glycans on pro-BNP had sialic acids at their termini, protecting it from O-glycosidase digestion. In contrast, pro-ANP and pro-CNP contained no detectable amounts of N- or O-glycans. Inhibition of O-glycosylation on pro-BNP did not prevent its expression in the cells. However, partially O-glycosylated pro-BNP was much less stable than fully O- glycosylated pro-BNP.

Conclusions: O-glycosylation is not necessary for pro-BNP expression but important for its stability.
Is Otomí creating a new lexical class for the modification of noun phrases as a result of the contact with Spanish?
Authors: Bakker Dik , Hekking Ewald
Published: March 2010

In this contribution we seek support for the hypothesis that Otomí, a language from Mexico, which is in intense contact with Spanish, is developing a specialized set of adjectives, a category that is lacking from the classical language. Arguments are derived from two sources, a corpus of translations into Otomí of around 750 Spanish adjectives, and a corpus of 59 short texts in spoken Otomí, in which a number of Spanish adjectives were found as loanwords. Pointing out several changes in the contemporary language, mainly among younger, often bilingual speakers, we provide support for our hypothesis, which suggests that Otomí is undergoing a typological change.
Code switching in Sia Pedee story-telling
Authors: Gómez Rendón Jorge
Published: March 2010

This article deals with code switching in a corpus of narratives collected in Sia Pedee (Chocoan) among the Épera of the northern Pacific coast of Ecuador. The reinsertion of Sia Pedee in the nowadays dominant Spanish-speaking ethnic community has resulted in older speakers making use of code switching as a way to flag their ethnic identity and index their attitudes towards propositional content. While code switching seems to be inducing certain incipient changes in Sia Pedee, the seriously endangered state of the native language would prevent those changes from taking definite shape. Similarly, the diglossic condition of Sia Pedee before Spanish is preventing the crystallization of a systematic pattern of language mixing.
Adrenocortical carcinoma: is the surgical approach a risk factor of peritoneal carcinomatosis?
Authors: Leboulleux S , Deandreis D , Al Ghuzlan A , Aupérin A , Goéré D , Dromain C , Elias D , Caillou B , Travagli J P , De Baere T , Lumbroso J , Young J , Schlumberger M , Baudin E
Published: March 2010

Context

Peritoneal carcinomatosis (PC) is a rare site of distant metastases in patients with adrenocortical cancer (ACC). One preliminary study suggests an increased risk of PC after laparoscopic adrenalectomy (LA) for ACC.

Objective

The objective of the study was to search for risk factors of PC including surgical approach.

Design

This was a retrospective cohort study conducted in an institutional practice.

Patients

Sixty-four consecutive patients with ACC seen at our institution between 2003 and 2009 were included. Mean tumor size was 132 mm. Patients had stage I disease in 2 cases, stage II disease in 32 cases, stage III disease in 7 cases, stage IV disease in 21 cases, and unknown stage disease in 2 cases. Surgery was open in 58 cases and laparoscopic in 6 cases.

Main outcome

The main outcome was the risk factors of PC.

Results

PC occurred in 18 (28%) patients. It was present at initial diagnosis in three cases and occurred during follow-up in 15 cases. The only risk factor of PC occurring during follow-up was the surgical approach with a 4-year rate of PC of 67% (95% confidence interval (CI), 30–90%) for LA and 27% (95% CI, 15–44%) for open adrenalectomy (P=0.016). Neither tumor size, stage, functional status, completeness of surgery, nor plasma level of op'DDD was associated with the occurrence of PC.

Conclusion

We found an increased risk of PC after LA for ACC. Whether this is related to an inappropriate surgical approach or to insufficient experience in ACC surgery should be clarified by a prospective program.
Head Injury Depth as an Indicator of Causes and Mechanisms
Authors: Hymel Kent P. , Stoiko Michael A. , Herman Bruce E. , Combs Amy , Harper Nancy S. , Lowen Deborah , Deye Katherine P. , Homa Karen , Blackman James A.
Published: March 2010

Objective:

The goal was to measure differences in the causes, mechanisms, acute clinical presentations, injuries, and outcomes of children <36 months of age with varying “greatest depths” of acute cranial injury.

Methods:

Children <36 months of age who were hospitalized with acute head trauma were recruited at multiple sites. Clinical and imaging data were collected, and caregivers underwent scripted interviews. Neurodevelopmental evaluations were completed 6 months after injury. Head trauma causes were categorized independently, and subject groups with varying greatest depths of injury were compared.

Results:

Fifty-four subjects were enrolled at 9 sites. Twenty-seven subjects underwent follow-up neurodevelopmental assessments 6 months after injury. Greatest depth of visible injury was categorized as scalp, skull, or epidural for 20 subjects, subarachnoid or subdural for 13, cortical for 10, and subcortical for 11. Compared with subjects with more-superficial injuries, subjects with subcortical injuries more frequently had been abused (odds ratio [OR]: 35.6; P < .001), more frequently demonstrated inertial injuries (P < .001), more frequently manifested acute respiratory (OR: 43.9; P < .001) and/or circulatory (OR: 60.0; P < .001) compromise, acute encephalopathy (OR: 28.5; P = .003), prolonged impairments of consciousness (OR: 8.4; P = .002), interhemispheric subdural hemorrhage (OR: 10.1; P = .019), and bilateral brain hypoxia, ischemia, or swelling (OR: 241.6; P < .001), and had lower Mental Developmental Index (P = .006) and Gross Motor Quotient (P < .001) scores 6 months after injury.

Conclusion:

For children <3 years of age, head injury depth is a useful indicator of injury causes and mechanisms.
The Effects of Hardness Variation on a CMP Model of Copper thin Films
Authors: Bonivel Joseph , Williams Yusuf , Blitz Sarah , Kuo Micheal , Kumar Ashok
Published: March 2010

With the rapid change of materials systems and decreased feature size, thin film microstructure and mechanical properties have become critical parameters for microelectronics reliability. An example of a major driver of this new technology is the data storage community who is pushing for 1 Terabit/square inch on its magnetic disk hard drives. This requires inherent knowledge of the mechanical properties of materials and in depth understanding of the tribological phenomena involved in the manufacturing process. Chemical mechanical polishing (CMP) is a semi-conductor manufacturing process used to remove or planarize ultra-thin metallic, dielectric, or barrier films (copper) on silicon wafers. The material removal rate (MRR), which ultimately effects the surface topography, corresponding to CMP is given by the standard Preston Equation, which contains the load applied, the velocity of the pad, the Preston coefficient which includes chemical dependencies, and the hardness of the material. Typically the hardness, a bulk material constant, is taken as a constant throughout the wafer and thereby included in the Preston coefficient. Through metallurgy studies, on the micro and nano scale, it has been proven that the hardness is dependent upon grain size and orientation. This research served to first relate the crystallographic orientation to a specific hardness value and secondly use the hardness variation in the previously developed particle augmented mixed-lubrication (PAML) model to simulate the surface topography and MRR during CMP. Recent test and results show that currently there is no empirical formula to relate the crystallographic orientation and thereby a critically resolved shear stress (CRSS) to a specific hardness value. The second part of this investigation utilized the variation in hardness values from the initial study and incorporated these results into the PAML numerical model that incorporates all the physics of chemical mechanical polishing (CMP). Incorporation of the variation of hardness resulted in a surface topography with a difference in roughness (Ra) from the bulk constant hardness value of 60 nm. The material removal rate (MRR) of the process differs by 2.17 μm3/s.
Novel End-point Detection Method by Monitoring Shear Force Oscillation Frequency for Barrier Metal Polishing in Advanced LSI
Authors: Gu Xun , Nemoto Takenao , Sampurno Yasa Adi , Cheng Jiang , Theng Sian Nie , Philipossian Ara , Zhuang Yun , Teramoto Akinobu , Ito Takashi , Sugawa Shigetoshi , Ohmi Tadahiro
Published: March 2010

A novel end-point detection method based on a combination of shear force and its spectral amplitude was proposed for barrier metal polishing on copper damascene structures. Under some polishing conditions, the shear force changed significantly with polished substrate. On the other hand, the change in shear force was insignificant under certain polishing conditions. Therefore, a complementary end-point detection method by monitoring oscillation frequency of shear force was proposed. It was found that the shear force fluctuated in unique frequencies depending on polished substrates. Using Fast Fourier Transformation, the shear force data was converted from time domain to frequency domain. The amplitude of spectral frequencies corresponding to the rotational rate of wafer carrier and platen was monitored. Significant frequency amplitude changes were observed before, during and after the polished layer transition from barrier film to silicon dioxide film. The results indicated that a combination of shear force and its spectral amplitude analyses provided effective end-point detection for barrier CMP process.
First-principles Study of PdAu Segregation with CO Coverage
Authors: Shan Bin , Hyun Jangsuk , Kapur Neeti , Cho Kyeongjae
Published: March 2010

Alloying has been one of the strategies to develop alternatives to Pt based CO oxidation catalyst. PdAu bimetallic alloy has recently been shown to have better reactivity and thermal stability toward CO oxidation for diesel engine applications as compared to pure metal catalysts. The key factor for low temperature light off in diesel engine catalysis is reactivity of alloy catalysts under CO environment, which in turn depends on the alloy surface composition and morphology. We explored the segregation processes in bimetallic Pd-Au alloy using first-principles calculations, assisted by a Monte-Carlo (MC) scheme that combines an improved Embedded Atom Method (EAM) and an atomistic treatment for adsorbed CO molecules for searching low energy states. Our simulation results show that PdAu surface changes from Au-rich to Pd-rich with increase in CO coverage up to 0.75 ML, beyond which additional CO adsorption is no longer favorable. A quantitative relationship between CO coverage and Pd concentrations on the surface is also revealed.
The Formation of Self-Assembled Nanowire Arrays on Ge(001): a DFT Study of Pt Induced Nanowire Arrays
Authors: Vanpoucke Danny Eric Paul , Brocks Geert
Published: March 2010

Nanowire (NW) arrays form spontaneously after high temperature annealing of a sub monolayer deposition of Pt on a Ge(001) surface. These NWs are a single atom wide, with a length limited only by the underlying beta-terrace to which they are uniquely connected. Using ab-initio density functional theory (DFT) calculations we study possible geometries of the NWs and substrate. Direct comparison to experiment is made via calculated scanning tunneling microscope (STM) images. Based on these images, geometries for the beta-terrace and the NWs are identified, and a formation path for the nanowires as function of increasing local Pt density is presented. We show the beta-terrace to be a dimer row surface reconstruction with a checkerboard pattern of Ge-Ge and Pt-Ge dimers. Most remarkably, comparison of calculated to experimental STM images shows the NWs to consist of germanium atoms embedded in the Pt-lined troughs of the underlying surface, contrary to what was assumed previously in experiments.
Theoretical and Experimental Study of Tip Electronic Structure in Scanning Tunneling Microscope
Authors: Choi HeeSung , Huang Min , Ballard Joshua B , He Kevin T , Schmucker Scott W , Lyding Joseph N , Randall John N , Cho Kyeongjae
Published: March 2010

The atomic and electronic structures of pyramidal model STM tips of transition metals (W, Rh, Pd, Ir and Pt) were investigated using density functional theory (DFT) method. The calculated density of states show that d electrons of the apex atoms in the M4 (M = W, Rh, Pd, Ir, Pt) model tips behave differently near the Fermi level, with the dz2 state being dominant only for W tip. The electronic structures of pyramid structures of W and Pd single-atom tips with larger sizes are studied and compared. The density of states of Pd apex atom and W apex atom show different occupation of d-bands leading to asymmetric density of states for Pd tip. The asymmetric tunneling currents measured by W and Pt-Ir STM tips are explained by the calculated electronic structures of W and Pd model tips.
Numerical Formulation of the Effective Medium Approximation: Illustrative Examples and Application to Organic Semiconductors
Authors: Graf Peter , Kose Muhammet , Kim Kwiseon
Published: March 2010

The effective medium approximation (EMA) approach to calculating the macroscopic properties of disordered materials from an average of microscopic interactions is logically divided into two parts. First, an expression based on the microscale physics of constituents embedded in the effective medium is derived. Second, a configurational average of some sort over is performed, leading to an equation for an effective parameter, which is then solved. Based on this division, we present a numerical approach to the EMA in which the effective parameter ?e satisfies
g(ξe) =  = ∫ f(σ,ξe)ρ(σ)dσ = 0.
Here, σ represents possible configurations of the system, i.e. some variable of the physical formulation with respect to which we have knowledge of both i) microscale interactions and ii) the distribution of constituents; f represents our knowledge of the microscale interactions as a function of σ; and ρ represents our knowledge of the distribution of the configurations/constituents with respect to σ. Then g is the expectation of f. The equation says that the average of the microscale interactions embodied in f, which is a function of the effective parameter ξe, over the possible configurations of the system represented by ρ(σ), is zero. This equation allows us to determine the effective parameter ξe, which, for example, we can compare to experiment, or use in a drift/diffusion type of macroscopic simulation. A key point is that our explicit formulation allows specifying ρ and f numerically (e.g. via Monte Carlo simulation).

We present both simple illustrative examples, as well as a realistic application to hopping transport in organic photovoltaics simulation. Preliminary results from this numerical EMA match experimental data remarkably well.
Impact of the Surrounding Network on the Si-O Bond-Breakage Energetics
Authors: Tyaginov Stanislav , Sverdlov Viktor , Gös Wolfgang , Scwaha Philipp , Heinzl Rene , Stimpfl Franz , Grasser Tibor
Published: March 2010

We extend the McPherson Model for silicon-oxygen bond-breakage derived for a single SiO4 tetrahedron to capture the influence of the whole lattice. Several pair-wise potentials have been compared in the model including Mie-Grüneisen as well as diverse forms of TTAM/BKS. The contribution of the whole lattice substantially increases the activation energy for the Si-O bond rupture. The corresponding small transition rate of a non-distorted Si-O bond suggests that the interaction with the electric field alone can not be responsible for the bond-breakage and the contribution of other components such as energy delivered by particles and/or bond weakening is required.ü