bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective roles of methionine‐R‐sulfoxide reductase against stresses in Schizosaccharomyces pombe
Authors: Jo Hannah , Cho Young‐Wook , Ji Sun‐Young , Kang Ga‐Young , Lim Chang‐Jin
Published: March 2013

The Schizosaccharomyces pombe msrB+ gene encoding methionine‐R‐sulfoxide reductase (MsrB) was cloned into the shuttle vector pRS316 to generate the recombinant plasmid pFMetSO. The msrB+ mRNA level was significantly increased in the S. pombe cells harboring pFMetSO, indicating that the cloned msrB+ gene is functioning. In the presence of 0.1 mM L‐methionine‐(R,S)‐sulfoxide, the S. pombe cells harboring pFMetSO could grow normally but the growth of the vector control cells was almost arrested. The S. pombe cells harboring pFMetSO exhibited the enhanced growth on the minimal medium plates with stress‐inducing agents, such as hydrogen peroxide, superoxide radical‐generating menadione (MD), nitric oxide (NO)‐generating sodium nitroprusside (SNP), and cadmium (Cd), when compared with the vector control cells. They also gave rise to the enhanced growth at the high incubation temperature of 37 °C than the vector control cells. The S. pombe cells harboring pFMetSO contained lower reactive oxygen species (ROS) and higher total glutathione (GSH) levels than the vector control cells. In brief, the S. pombe MsrB plays a protective role against oxidative, nitrosative, and thermal stresses, and is involved in diminishing intracellular ROS level.
Tuning SERS for living erythrocytes: Focus on nanoparticle size and plasmon resonance position
Authors: Brazhe N. A. , Parshina E. Y. , Khabatova V. V. , Semenova A. A. , Brazhe A. R. , Yusipovich A. I. , Sarycheva A. S. , Churin A. A. , Goodilin E. A. , Maksimov G. V. , Sosnovtseva O. V.
Published: March 2013

Surface‐enhanced Raman spectroscopy (SERS) is a unique technique to study submembrane hemoglobin (Hbsm) in erythrocytes. We report the detailed design of SERS experiments on living erythrocytes to estimate dependence of the enhancemen t factor for main Raman bands of Hbsm on silver nanoparticle (AgNP) properties. We demonstrate that the enhancement factor for ν 4/A1g, ν 10/B1g and A2g Raman bands of Hbsm varies from 105 to 107 under proposed experimental conditions with 473 nm laser excitation. For the first time we show that the enhancement of Raman scattering increases with the increase in the relative amount of small NPs in colloids, with the decrease in AgNP size and with plasmon resonance shift to the shorter wavelength region. Obtained results can be explained by the ability of smaller AgNPs to get deeper into nano‐invaginations of the plasma membrane than larger AgNPs. This shortens the distance between small AgNPs and Hbsm and, consequently, leads to the higher enhancement of Raman scattering of Hbsm. The enhancement of higher wavenumber bands ν 10/B1g and A2g is more sensitive to AgNPs’ size and the relative amount of small AgNPs than the enhancement of the lower wavenumber band ν 4/A1g. This can be used for AgNP‐controlled enhancement of the desired Raman bands and should be taken into account in biomedical SERS experiments. Copyright © 2013 John Wiley & Sons, Ltd.
Single‐shot thermometry using fiber‐based picosecond coherent anti‐stokes Raman scattering (CARS) spectroscopy
Authors: Hsu Paul S. , Kulatilaka Waruna D. , Gord James R. , Roy Sukesh
Published: March 2013

Coherent anti‐Stokes Raman scattering (CARS)‐spectroscopy‐based thermometry techniques developed for laboratory flames face a stiff challenge when implemented in practical combustion environments such as engine test facilities. In addition to limited optical access, the harsh environments associated with these test facilities (i.e. uncontrolled humidity, vibration, and large thermal gradients) often restrict the operation of sensitive laser systems. To circumvent this problem, we have developed a fiber‐based, picosecond (ps) CARS system employing long‐length (up to 6 m), multimode silica fibers that permits the laser system to be isolated from the high heat and vibration of the test hardware. Proof‐of‐principle, single‐laser‐shot temperature measurements using a 3‐m‐long fiber system are demonstrated in atmospheric pressure, near‐adiabatic, laboratory H2–air flames. Limitations that are imposed by long‐length multimode‐fiber beam delivery for CARS thermometry are identified as nonlinear effects during beam propagation along the fiber, depolarization of the laser beam, and degradation of the beam quality at the output of the fiber. These effects are investigated in detail, and potential improvements are suggested. The current study shows promise for implementation of fiber‐based ps‐CARS spectroscopy in harsh environments such as those encountered in combustors and afterburners in practical gas‐turbine‐engine test facilities. Copyright © 2013 John Wiley & Sons, Ltd.
Rapid eye movement sleep behavior disorder in Parkinson's disease: Magnetic resonance imaging study
Authors: Ford Andrew H. , Duncan Gordon W. , Firbank Michael J. , Yarnall Alison J. , Khoo Tien K. , Burn David J. , O'Brien John T.
Published: March 2013

Background

Rapid eye movement sleep behavior disorder has poor prognostic implications for Parkinson's disease. The authors recruited 124 patients with early Parkinson's disease to compare clinical and neuroimaging findings based on the presence of this sleep disorder.

Methods

The presence of rapid eye movement sleep behavior disorder was assessed with the Mayo Sleep Questionnaire. Magnetic resonance imaging sequences were obtained for voxel‐based morphometry and diffusion tensor imaging.

Results

Patients with sleep disorder had more advanced disease, but groups had similar clinical characteristics and cognitive performance. Those with sleep disorder had areas of reduced cortical grey matter volume and white matter changes compared with those who did not have sleep disorder. However, differences were slight and were not significant when the analyses were adjusted for multiple comparisons.

Conclusions

Rapid eye movement sleep behavior disorder was associated with subtle changes in white matter integrity and grey matter volume in patients with early Parkinson's disease. © 2013 Movement Disorder Society
Ethnic group differences in cardiometabolic disease risk factors independent of body mass index among American youth
Authors: Messiah Sarah E. , Arheart Kristopher L. , Lopez‐Mitnik Gabriela , Lipshultz Steven E. , Miller Tracie L.
Published: March 2013

Objective: The purpose of this analysis was to identify any ethnic group differences in the prevalence of cardiometabolic disease risk factors independent of BMI in United States youth.

Design and Methods: Data on 3,510 boys and girls aged 8‐11 years from the 1999‐2008 National Health and Nutrition Examination Surveys were analyzed to determine the prevalence of 1 or ≥3 cardiometabolic disease risk factors: abnormal waist circumference and systolic (SBP) and diastolic blood pressure (DBP), increased concentrations of fasting triglyceride, and decreased concentrations of high‐density lipoprotein (HDL) cholesterol before and after adjusting for BMI.

Results: Abnormal waist circumference and HDL‐cholesterol significantly differed by ethnic group before and after adjusting for BMI (P < 0.01). Non‐Hispanic blacks were significantly less likely to have abnormal HDL‐cholesterol concentrations than were Hispanics and non‐Hispanic whites, but non‐Hispanic whites were significantly more likely to have elevated triglycerides and three or more abnormal cardiometabolic risk factors than non‐Hispanic blacks.

Conclusion: These findings point to ethnic group disparities not related to BMI alone, even in children as young as 8‐11 years. Programs to prevent and treat eventual cardiometabolic disease in children could be tailored for specific ethnic backgrounds as a result.
Comparative Evaluation of Single Fixed Dosing and Weight‐Based Dosing of Rasburicase for Tumor Lysis Syndrome
Authors: McBride Ali , Lathon Sherrie C. , Boehmer Leigh , Augustin Kristan M. , Butler Sara K. , Westervelt Peter
Published: March 2013

Study Objective

To evaluate single fixed dosing versus weight‐based dosing strategies for rasburicase to determine the minimum dose required to mitigate hyperuricemia in the treatment or prevention of tumor lysis syndrome.

Design

Retrospective medical record review

Setting

Academic medical center

Patients

A total of 373 patients with a diagnosis of a hematologic malignancy or solid tumor and who received at least one dose of rasburicase over a 6‐year period between January 1, 2005, and February 18, 2011; 180 patients received single doses of 3 mg (38 patients), 6 mg (99 patients), or 7.5 mg (43 patients), and 193 patients received weight‐based dosing.

Measurements and Main Results

Tumor lysis syndrome laboratory data were recorded at baseline and monitored up to 72 hours after initial rasburicase administration. Median baseline plasma uric acid levels were 6.85 mg/dl, 8.80 mg/dl, 8.00 mg/dl, and 9.20 mg/dl, respectively, in the 3‐mg, 6‐mg, 7.5‐mg, and weight‐based dosing groups. Treatment success was defined as a normalized plasma uric acid level (< 7.5 mg/dl) within 24 hours after receiving rasburicase. The mean weight‐based dose was 0.16 mg/kg. Six rasburicase treatment failures occurred; two were in the 3‐mg group, one was in the 6‐mg group, and three were in the weight‐based dosing group. At 24 hours after rasburicase administration, no statistically significant differences in treatment success were noted among groups (92.9% vs 97.6% vs 100.0% vs 98.0% in the 3‐mg, 6‐mg, 7.5‐mg, and weight‐based dosing groups, respectively, p=0.1238).

Conclusion

The efficacy of all single fixed doses and weight‐based dosing strategies evaluated in this study appear to be comparable in normalizing plasma uric acid levels within 24 hours of rasburicase administration. Although use of a 3‐mg rasburicase dose may be the most cost‐effective treatment strategy in managing hyperuricemia secondary to tumor lysis syndrome, the 6‐mg dose resulted in lower sustained uric acid levels after rasburicase administration. Further analysis of patient specific factors contributing to the need for repeat rasburicase administration should be conducted in larger, prospective clinical trials.
Pharmacokinetics and Pharmacodynamics of Atazanavir‐containing Antiretroviral Regimens, with or without Ritonavir, in Patients who are HIV‐positive and Treatment‐naïve
Authors: Bertz Richard J. , Persson Anna , Chung Ellen , Zhu Li , Zhang Jenny , McGrath Donnie , Grasela Dennis
Published: March 2013

Study Objective

To investigate the pharmacokinetic and pharmacodynamic relationships of the human immunodeficiency virus (HIV)–protease inhibitor atazanavir (ATV) in the presence and absence of the pharmacokinetic booster ritonavir, utilizing ATV plasma trough concentrations (Ctrough) and clinical biomarkers of antiviral efficacy and safety over 48 weeks.

Design

Randomized, open‐label, multicenter, study designed to compare the efficacy and safety of ATV 300 mg plus ritonavir 100 mg (ATV300/r) with that of ATV 400 mg (ATV400).

Setting

Thirty clinic sites across 10 countries in Africa, Europe, North America, and South America.

Patients

Patients who were HIV‐positive and treatment‐naïve.

Interventions

Randomized to once‐daily ATV400 (105 patients) or ATV300/r (95 patients) plus lamivudine and extended‐release stavudine.

Measurements and Main Results

The Ctrough approximately 24 hours after the prior unobserved dose was measured through week 48. Composite Ctrough (i.e., the geometric mean of all trough concentrations over the 48 weeks), population inhibitory quotient ([IQ], i.e., Ctrough divided population estimated protein binding adjusted effective concentration at 90% [EC90, 14 ng/ml]), composite population IQ (i.e., ATV composite trough divided by population estimated protein binding adjusted EC90), HIV RNA, CD4 cell counts, and metabolic and safety parameters were also assessed. For ATV400 and ATV300/r, respectively, geometric mean composite Ctrough (CV%) were 127 (106) ng/ml and 670 (63) ng/ml, geometric mean composite population IQ were 9 and 48, and composite Ctrough values of HIV EC90 or more were achieved in 98% and 100% of patients. High ATV Ctrough was associated with low HIV RNA at week 48; however, 88% of patients had HIV RNA less than 400 copies/ml in the lowest composite Ctrough quartile. There was no clear relationship between ATV Ctrough and changes in CD4 cell count. Increases in total bilirubin or jaundice were associated with higher Ctrough. Modest increases in triglycerides and cholesterol were associated with the addition of ritonavir.

Conclusion

ATV‐containing regimens with or without ritonavir achieved ATV exposures that provide robust antiretroviral efficacy and acceptable tolerability in treatment‐naïve patients.
Life‐Threatening Hypoglycemia Associated with Intentional Insulin Ingestion
Authors: Svingos Robert S. , Fernandez Erica M. , Reeder Don N. , Parker John J.
Published: March 2013

There are reports of insulin overdose by injection, yet little is known regarding the potential harms of intentional oral ingestion of insulin. In this report, we describe a case of massive insulin ingestion and ensuing hypoglycemia. To our knowledge, there are no previously published cases of hypoglycemia caused by intentional insulin ingestion. A 51‐year‐old man intentionally ingested three 10‐ml vials (total of 3000 units) of various insulins: one vial each of insulin aspart, lispro, and glargine. Four symptomatic hypoglycemic episodes, with blood glucose levels of 48, 25, 34, and 40 mg/dl, occurred approximately 1, 3, 4, and 5 hours, respectively, after ingestion. The hypoglycemia could not be explained other than the ingestion of the insulins. The patient was admitted for observation, and euglycemia occurred within 24 hours without any additional hypoglycemic episodes. Hypoglycemia treatment is reviewed in this case report, and factors that may affect systemic response of orally ingested insulin, including gastrointestinal absorption and insulin sensitivity, are discussed. In addition, the findings of our case report may provide useful insight into the development of novel oral insulin products that are currently in research. Despite poor bioavailability (1%) when taken orally, insulin may produce symptomatic hypoglycemia with a massive ingestion. Vigilant blood glucose monitoring, supportive care with glucose replacement therapy, and admission to the hospital for observation may be required.
Shotgun proteomic analysis of two Bartonella quintana strains
Authors: Fabietti Alessandra , Gaspari Marco , Krishnan Shibu , Quirino Angela , Liberto Maria Carla , Cuda Giovanni , Focà Alfredo
Published: March 2013

This study reports the first extensive shotgun analysis of the Bartonella quintana proteome. Proteins extracted from two B. quintana strains, Oklahoma and JK31, were analyzed in triplicate analyses by a bottom‐up approach consisting of tryptic digestion in SDS‐containing buffer, strong cation‐exchange StageTip fractionation, and nano‐LC‐MS/MS analysis. By setting spectral false discovery rate below 0.5%, 548 unique proteins were identified overall, of which 409 protein identifications were shared between the two strains. The data set, which achieves the highest proteome coverage for B. quintana to date, could be exploited for the quantitative analysis of a selected subset of target proteins.
Nanoassemblies with light‐responsive size and density from linear flexible polyelectrolytes
Authors: Moldenhauer Daniel , Gröhn Franziska
Published: March 2013

This study presents electrostatically self‐assembled nanoparticles from linear flexible polyelectrolytes (poly(diallyldimethylammonium chloride or quarternized poly(4‐vinylpyridine)) and an ionic photo‐isomerizable azo dye (Acid Yellow 38) that can change their size upon UV‐light irradiation. Assemblies with narrow size distribution are stable in aqueous solution. For samples with under‐stoichiometric dye load, UV‐light exposure triggers a size decrease, e.g. from a hydrodynamic radius of Rh = 94 nm to Rh = 62 nm for an Ay38‐PDADMAC sample with a charge ratio of lcharge = 0.7. Size changes are caused by trans‐cis isomerization of the dye, accompanied by a change in hydrophilicity, binding enthalpy and entropy. Assemblies are characterized by static and dynamic light scattering, atomic force microscopy, UV–vis spectroscopy and isothermal titration calorimetry. Zeta potential measurements give insight into the electrostatic stabilization and size‐control of the ionic nano‐assemblies, revealing a master curve of effective surface charge density versus hydrodynamic radius. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys., 2013
Functional peptides for capacitative detection of Ca2+ ions
Authors: Hitzbleck Martina , Vu Xuan Thang , Ingebrandt Sven , Offenhäusser Andreas , Mayer Dirk
Published: March 2013

Molecular recognition is the key feature of bioinspired sensor applications. A profound understanding of recognitive binding events is crucial for the design of highly specific and effective binding molecules. In this paper a series of simple to complex oligopeptides, derived from the Ca2+ chelator ethylenediaminetetraacetic acid (EDTA) and the Ca2+ binding protein calmodulin, were investigated. It was shown, that specifically designed oligopeptides can fulfil protein‐like recognition functions but are much easier to immobilize and enable high functional integration. Impedance spectroscopy (IS) could be used to detect binding of Ca2+ to different peptides because the double layer capacitance is highly sensitive to changes in the morphology and dielectric properties of adsorbate layers. Finally, the designed functional oligopeptides were implemented in silicon nanowire field effect transistors (SiNW FETs) as a proof of concept for future problem‐optimized molecules in sensor devices.

The graph shows frequency‐normalized admittance plots and corresponding schemes of a peptide monolayers layer before and after binding of Ca2+ ions.
Dielectric spectroscopy study of hydrogen treated lead zirconate titanate (Pb (Zr,Ti)O3)
Authors: Shafiei A. , Troczynski T.
Published: March 2013

Dielectric spectroscopy technique is used in this work to study the structural changes inside lead zirconate titanate (Pb (Zr,Ti)O3 or PZT) exposed to hydrogen for 24 h at 550 °C, at constant pressure p = 0.13 bar. The results show that even after hydrogen treatment, there are still spontaneous dipoles (TiO or ZrO) inside the PZT. However, the dielectric constant is only about half of that of the as‐received sample. After the hydrogen treatment, two relaxation peaks were observed in the dissipation factor curves. While the kinetics of one of the relaxation peaks obeys the classical Arrhenius law, the other peak shows a non‐monotonic relaxation kinetics. Possible reasons for the formation of these peaks have been discussed.
MOF‐FF – A flexible first‐principles derived force field for metal‐organic frameworks
Authors: Bureekaew Sareeya , Amirjalayer Saeed , Tafipolsky Maxim , Spickermann Christian , Roy Tapta Kanchan , Schmid Rochus
Published: March 2013

In this contribution the development, definition and selected applications of a new force field (FF) for metal‐organic frameworks MOF‐FF is presented. MOF‐FF is fully flexible and is parameterized in a systematic and consistent fashion from first principles reference data. It can be used for a variety of different MOF‐families and in particular – due to the reparametrization of a variety of organic linkers – also to explore isoreticular series of systems. The history of the development, leading to the final definition of MOF‐FF is reviewed along with the application of the previous incarnations of the FF. In addition, the parametrization approach is explained in a tutorial fashion. The currently parametrized set of inorganic building blocks is constantly extended.

magnified image

Formate models of currently covered inorganic building blocks.
The processing of electron density profiles from the Mars Express MARSIS topside sounder
Authors: Morgan D. D. , Witasse O. , Nielsen E. , Gurnett D. A. , Duru F. , Kirchner D. L.
Published: March 2013

We here present a manual for the reduction of data from ionograms obtained from the Mars Express MARSIS Active Ionospheric Sounding topside radar sounder. Sample data are presented with the procedure for processing them explained as simply as possible. We discuss the uncertainties inherent in the measurements as well as systematic problems with the data. A sample code is included to facilitate the inversion process. We also include a comparison with an electron density profile taken from the Mars Express Radio Science occultation experiment, showing agreement between the two methods, although the data are not simultaneous.
Fluency Idol: Using Pop Culture to Engage Students and Boost Fluency Skills
Authors: Calo Kristine M. , Woolard‐Ferguson Taylor , Koitz Ellen
Published: March 2013

This article shares an oral reading practice that develops children's fluency skills, with a particular emphasis on performance reading and prosody. The authors share their experiences with Fluency Idol! as a way to engage young children by tapping into pop culture. The practice emphasizes repeated readings, feedback, practice, and performance while encouraging children to read aloud to one another. Applications to a second grade classroom as well as in a college reading clinic are discussed.
Common Core, Commonplaces, and Community in Teaching Reading
Authors: Roskos Kathleen , Neuman Susan B.
Published: March 2013

Joseph Schwab, a curriculum theorist, described four commonplaces, or universals, of teaching: content, students, milieu and teachers. This article considers how the Reading Standards of the ELA‐CCSS are shaping these commonplaces in the teaching of reading. The organization of the Reading Standards, for example, focuses on two broad grade bands, K‐5; 6‐12 and its framework outlines curriculum content in three categories, foundations, literacy and informational reading. As a core set of expectations, the Reading Standards challenge learners of all ages and require a more participatory literacy environment. They ask more of beginning teachers who must set a brisk pace in reading instruction if students are to achieve expectations. The importance of community in building strong reading programs that meet high core standards is emphasized. New teachers are strongly encouraged to become actively involved in the implementation of core Reading Standards in their local professional communities.
Living Inquiry: Learning From and About Informational Texts in a Second‐Grade Classroom
Authors: Maloch Beth , Horsey Michelle
Published: March 2013

This article tells the story of one second grade teacher and the ways she integrated informational texts into her classroom. Reported by the classroom teacher and a researcher who studied her practice for a year, the manuscripts details the ways Michelle (the classroom teacher) embedded informational texts in her classroom primarily within the context of inquiry. The two authors first report on the ways Michelle integrated informational texts across the school day and school year, and then present in more detail one inquiry unit on habitats. The authors conclude by arguing that that learning about informational texts is most productive when embedded within inquiry‐focused classrooms engaged in learning from informational texts.
Severe left heart obstruction with retrograde arch flow influences fetal cerebral and placental blood flow
Authors: Yamamoto Y. , Khoo N. S. , Brooks P. A. , Savard W. , Hirose A. , Hornberger L. K.
Published: March 2013

Objective

Decreased middle cerebral artery (MCA) pulsatility index (PI) is a marker of fetal brain‐sparing in placental insufficiency and it is also found in fetuses with severe congenital heart disease. This study sought to explore the impact of anatomical subtypes in fetal heart disease on MCA‐PI and head growth.

Methods

We retrospectively reviewed fetal echocardiograms of pregnancies complicated by fetal hypoplastic left heart syndrome (HLHS; n = 42) with and without anatomic coarctation (n = 28 and n = 10, respectively), isolated severe aortic coarctation (n = 21), D‐transposition of the great arteries (TGA; n = 11) and pulmonary outflow tract obstruction without forward flow across the pulmonary valve (POTO; n = 15), comparing observations with gestational age‐matched controls (n = 89). No fetus had major extracardiac pathology or aneuploidy. MCA and umbilical artery (UA) PI, the cerebral placental ratio (CPR  =  MCA‐PI/ UA‐PI) and neonatal head circumference were obtained and expressed as Z‐scores.

Results

Lower MCA‐PI, higher UA‐PI and lower CPR were observed in fetal HLHS and isolated coarctation with reversed arch flow (n = 6) (P < 0.001) but not TGA, POTO or isolated coarctation with antegrade arch flow (n = 15) compared with controls. No difference was found between HLHS with anatomical coarctation and those without; however, MCA‐PI correlated positively with neonatal head circumference in HLHS with reversed distal arch flow (r = 0.33, P < 0.05).

Conclusions

Severe left heart obstruction with reversed aortic arch flow is associated with altered fetal cerebral blood flow, and in these conditions, MCA‐PI positively correlates with head growth. Anatomical arch obstruction itself may not be a contributing factor to altered MCA flow in fetal HLHS. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Horizontal spatial correlation of hydraulic and reactive transport parameters as related to hierarchical sedimentary architecture at the Borden research site
Authors: Ritzi R. W. , Huang L. , Ramanathan R. , Allen‐King R. M.
Published: March 2013

Key Points

auto and cross correlation have a common correlation structure

correlation structure is defined by hierarchical sedimentary architecture

stratal lengths at different scales define correlation substructures
Traveling wave solution of the Boussinesq equation for groundwater flow in horizontal aquifers
Authors: Basha H. A.
Published: March 2013

Key Points

Simplified model of the water table response to transient stream level changes

Algebraic equations for the stream‐aquifer exchange flow rates and volumes

An improved working relationship for aquifer parameter estimation
Assimilation of stream discharge for flood forecasting: The benefits of accounting for routing time lags
Authors: Li Yuan , Ryu Dongryeol , Western Andrew W. , Wang Q. J.
Published: March 2013

Key Points

EnKF overcorrects soil moisture in catchment models as it ignores the time lag

EnKS gives better forecasts when routing is not directly updated

EnKS and EnKF gives equivalent results when routing is updated
Early and Late Presentations of Graft Arterial Pseudoaneurysm Following Pancreatic Transplantation
Authors: Lubezky Nir , Goykhman Yaacov , Nakache Richard , Kessler Ada , Baruch Roni , Katz Paulina , Kori Itzhak , Klausner Joseph M. , Ben‐Haim Menahem
Published: March 2013

Background

Graft pseudoaneurysm (PSA) following pancreatic transplantation (PT) is a rarely reported complication that has significant morbidity and mortality. Few case reports and small series of this complication exist.

Methods

Retrospective review of files of 106 patients who underwent PT at the Tel‐Aviv Sourasky Medical center between 1995 and 2010. Accessible asymptomatic patients (n = 35) were referred for graft PSA screening using ultrasound‐Doppler.

Results

Eight patients developed graft PSA (8 %). All had early posttransplant sepsis. PSA incidence among patients who had perioperative sepsis is 13 %. Three patients developed early postoperative PSA, presenting as massive abdominal bleeding requiring urgent laparotomy and graft resection. Five patients were diagnosed with late‐onset graft PSA between 3 months and 11 years posttransplant: clinical presentations were massive gastrointestinal bleeding (n = 2), acute renal failure (n = 1), and asymptomatic finding on screening ultrasound‐Doppler (n = 2, 6 % of screened patients).

Conclusions

PSA following PT occurs in 8 % of patients. Perioperative infection is a risk factor. Early PSAs present as massive intra‐abdominal bleeding. PSA may develop years posttransplant, may be asymptomatic, but late rupture is possible and presents as gastrointestinal bleeding. We recommend screening of patients at risk with ultrasound Doppler for early detection and treatment of asymptomatic PSAs.
The Bernese peri-acetabular osteotomy through a modified approach. A technical note
Authors: Whittingham-Jones Paul , Kirit Patel Nirav , Hashemi-Nejad Aresh
Published: March 2013

Introduction

A modification of the technique for performing the Bernese periacetabular osteotomy is described.

Materials and methods

A medial approach to the Ischium and a subtle re-orientation of the pubic osteotomy are detailed.

Conclusion

Surgical morbidity is likely decreased with a concurrent cosmetic advantage without compromise to surgical correction or patient safety.
A conceptual-driven survey on future internet requirements, technologies, and challenges
Authors: Alberti Antonio Marcos
Published: March 2013

Nowadays, research initiatives to redesign the Internet are popping up around the world. Each of these projects has a particular focus and its own set of design requirements and key technologies. The panorama shows a wide diversity of pre-requirements and arguments, some very specific and superficial, others more general and deep. Despite this diversity, a conceptual-driven analysis of such scenario could reveal the current state-of-the-art on future Internet research, the common aspects that permeate all initiatives, and the open issues to be addressed in future work. This paper provides a comprehensive overview of the contemporary research from an abstract point of view, covering the design requirements and ingredients that are being adopted, interrelating, and analyzing them.
Spectrum of group cohomology and support varieties
Authors: Friedlander Eric M.
Published: March 2013

We give a brief introduction to two fundamental papers by Daniel Quillen appearing in the Annals, 1971. These papers established the foundations of equivariant cohomology and gave a qualitative description of the cohomology of an arbitrary finite group. We briefly describe some of the influence of these seminal papers in the study of cohomology and representations of finite groups, restricted Lie algebras, and related structures.
Daniel Quillen, the father of abstract homotopy theory
Authors: Thomas Jean-Claude , Vigué-Poirrier Micheline
Published: March 2013

In this short paper we try to describe the fundamental contribution of Quillenin the development of abstract homotopy theory and we explain how he uses this theory to lay the foundations of rational homotopy theory.
Saproxylic community, guild and species responses to varying pheromone components of a pine bark beetle
Authors: Etxebeste Iñaki , Lencina José L. , Pajares Juan
Published: March 2013

Some bark beetle species (Coleoptera: Scolytinae) produce aggregation pheromones that allow coordinated attack on their conifer hosts. As a new saproxylic habitat is founded, an assemblage of associated beetles kairomonally respond to bark beetle infochemicals. Ips sexdentatus is one of the major damaging insects of Pinus spp. in Southern Europe. Its response to varying ipsenol (Ie) percentages in relation to ipsdienol (Id) was studied in northwestern Spain, along with the entire saproxylic beetle assemblage captured at multiple-funnel traps. Response profile modeling was undertaken for I.sexdentatus sexes and sex-ratios, associated species and for selected trophic groups using a reference Gaussian model. In addition, the effects on the saproxylic assemblages were analyzed. I. sexdentatus response curve peaked at 22.7% Ie content, while remaining taxa that could be modeled, peaked above ca. 40% Ie. Predator guilds showed a linear relationship with Ie proportion, while competitors showed a delayed response peak. Consequently, species assemblages differed markedly between varying pheromone component mixtures. Given that the evaluated pheromonal proportions mimicked that of logs being colonized by I. sexdentatus, results suggested that the registered differential responses at different levels might provide I.sexdentatus with a temporal window that maximizes conspecific attraction while reducing interference with competitor and predatory guilds. Described responses might help improve the monitoring of the population status of target bark beetles and their associates, but also point toward the by-catch of many natural enemies, as well as rare saproxylic beetle species, interfering with the aims of sustainable forest management.
Topological structure of fractal squares
Authors: LAU KA–SING , LUO JUN JASON , RAO HUI
Published: March 2013

Given an integer n ≥ 2 and a digit set ⊊ {0,1,. . .,n − 1}2, there is a self-similar set F ⊂ ℝ2 satisfying the set equation: F=(F+)/n. We call such F a fractal square. By studying a periodic extension H= F + ℤ2, we classify F into three types according to their topological properties. We also provide some simple criteria for such classification.
SEIBERG–WITTEN FLOW IN HIGHER DIMENSIONS
Authors: SCHABRUN LORENZ
Published: March 2013

We show that for manifolds of dimension $m\geq 5$, the flow of a Seiberg–Witten-type functional admits a global smooth solution.
Role of melanin-concentrating hormone in the nucleus accumbens shell in rats behaviourally sensitized to methamphetamine
Authors: Sun Li-li , Zhang Yan , Liu Jian-feng , Wang Jun , Zhu Wei-li , Zhao Li-yan , Xue Yan-xue , Lu Lin , Shi Jie
Published: March 2013

Melanin-concentrating hormone (MCH) is a neuropeptide and its receptor is extensively expressed throughout the brain. MCH has been suggested to regulate the rewarding and reinforcing effects of psychostimulants by potentiating the dopaminergic system within the midbrain. Moreover, MCH and its receptor can regulate ERK activity. The present study investigated the role of MCH in the nucleus accumbens (NAc) in rats behaviourally sensitized to methamphetamine (Meth). We found that the development of Meth-induced locomotor sensitization was attenuated by MCH infused into the NAc shell but not core. Moreover, the elevation of ERK phosphorylation in the NAc shell induced by Meth was inhibited by locally infused MCH. Infusion of the MCH receptor 1 (MCHR1) antagonist SNAP 94847 into the NAc shell but not core augmented the initiation of locomotor sensitization and amplitude of elevated phosphorylated ERK levels induced by Meth. The expression of Meth-induced locomotor sensitization and ERK alterations after 1 wk withdrawal were not affected by either MCH or SNAP 94847 infused into the NAc shell or core. These results indicate that MCH in the NAc shell plays a critical role in the development but not expression of Meth-induced locomotor sensitization in rats, which might be mediated by the ERK signalling pathway. Our study suggests that MCH might be a potential target for the treatment of Meth addiction.
Hypersplenismus
Authors: Jeker Raphael
Published: March 2013

Der Begriff Hypersplenismus ist charakterisiert durch eine Zytopenie einer oder mehrerer Zellreihen des Blutes bei einem normo- bis hyperzellulärem Knochenmark aufgrund einer Splenomegalie mit Sequestrierung der Blutzellen. Es ist ein häufiges Begleitphänomen bei portaler Hypertension im Rahmen einer Leberzirrhose. In seltenen Fällen ist der Hypersplenismus symptomatisch mit vermehrter Blutungsneigung oder hämolytischer Anämie. Wichtig ist an die Differentialdiagnose Hypersplenismus zu denken, da therapeutische Möglichkeiten vorhanden sind. Die Splenektomie nach vorgängiger Immunisierung ist die Therapie der Wahl. Bei hohem Operationsrisiko ist die arterielle partielle Milzembolisation eine vertretbare Alternative.
Rovibronically selected and resolved two-color laser photoionization and photoelectron study of cobalt carbide cation
Authors: Huang Huang , Chang Yih Chung , Luo Zhihong , Shi Xiaoyu , Lam Chow-Shing , Lau Kai-Chung , Ng C. Y.
Published: March 2013

We have conducted a two-color visible-ultraviolet (VIS-UV) resonance-enhanced laser photoionization efficiency and pulsed field ionization-photoelectron (PFI-PE) study of gaseous cobalt carbide (CoC) near its ionization onset in the total energy range of 61 200–64 510 cm−1. The cold gaseous CoC sample was prepared by a laser ablation supersonically cooled beam source. By exciting CoC molecules thus generated to single N′ rotational levels of the intermediate CoC*(2Σ+; v′) state using a VIS dye laser prior to UV laser photoionization, we have obtained N+ rotationally resolved PFI-PE spectra for the CoC+(X1Σ+; v+ = 0 and 1) ion vibrational bands free from interference by impurity species except Co atoms produced in the ablation source. The rotationally selected and resolved PFI-PE spectra have made possible unambiguous rotational assignments, yielding accurate values for the adiabatic ionization energy of CoC(X2Σ+), IE(CoC) = 62 384.3 ± 0.6 cm−1 (7.73467 ± 0.00007 eV), the vibrational frequency ωe+ = 985.6 ± 0.6 cm−1, the anharmonicity constant ωe+χe+ = 6.3 ± 0.6 cm−1, the rotational constants (Be+ = 0.7196 ± 0.0005 cm−1, αe+ = 0.0056 ± 0.0008 cm−1), and the equilibrium bond length re+ = 1.534 Å for CoC+(X1Σ+). The observation of the N+ = 0 level in the PFI-PE measurement indicates that the CoC+ ground state is of 1Σ+ symmetry. Large ΔN+ = N+ − N′ changes up to 6 are observed for the photoionization transitions CoC+(X1Σ+; v+ = 0–2; N+) ← CoC*(2Σ+; v′; N′ = 6, 7, 8, and 9). The highly precise energetic and spectroscopic data obtained in the present study have served as a benchmark for testing theoretical predictions based on state-of-the-art ab initio quantum calculations at the CCSDTQ/CBS level of theory as presented in the companion article.
The effect of emissive biased limiter on the magnetohydrodynamic modes in the IR-T1 tokamak
Authors: Ghasemloo M. , Ghoranneviss M. , Salem M. K. , Arvin R. , Mohammadi S. , Nik Mohammadi A.
Published: March 2013

A moveable emissive biased limiter (EBL) for the investigation of spatial and temporal structure of MHD modes in IR-T1 tokamak, based on mirnov oscillations, was designed and constructed. The biasing has been considered to improve the global confinement by setting up an electric field at the plasma edge. Radial electric field (Er) modifies edge plasma turbulence, plasma rotation, and transport. Mirnov oscillations using singular value decomposition (SVD) and wavelet techniques were analyzed. SVD algorithm has been employed to analyze the frequency and wavenumber harmonics of the MHD fluctuations. The time-resolved frequency component analysis has been performed using wavelets. The EBL was applied to plasma at 10 ms with negative polarity. The results show that after applying EBL, the m = 2 mode is grown, m = 3 mode is suppressed, and Hα radiation is decreased. Furthermore, results of the wavelet analysis of mirnov coil in the time range of 8–12 ms indicate that 1.5 ms after applying EBL, the MHD frequency is reduced from 45 kHz to 25 kHz.
Recycling random numbers in the stochastic simulation algorithm
Authors: Yates Christian A. , Klingbeil Guido
Published: March 2013

The stochastic simulation algorithm (SSA) was introduced by Gillespie and in a different form by Kurtz. Since its original formulation there have been several attempts at improving the efficiency and hence the speed of the algorithm. We briefly discuss some of these methods before outlining our own simple improvement, the recycling direct method (RDM), and demonstrating that it is capable of increasing the speed of most stochastic simulations. The RDM involves the statistically acceptable recycling of random numbers in order to reduce the computational cost associated with their generation and is compatible with several of the pre-existing improvements on the original SSA. Our improvement is also sufficiently simple (one additional line of code) that we hope will be adopted by both trained mathematical modelers and experimentalists wishing to simulate their model systems.
Performance analysis and exhaust emissions of neem methyl ester operated compression ignition engine
Authors: Singh Yadav Vinod , Khatri Kamal Kishore , Tanwar Deepak , Ajayta  , Sharma Dilip , Soni S. L.
Published: March 2013

Neem oil methyl ester (NOME) was prepared from neem oil using alkaline catalyzed transesterification. The important fuel properties of NOME, 20% blend of NOME with diesel, were compared with those of diesel. Optimum injection pressures were determined for neat diesel and NOME-20 blend. Comparison of brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), and smoke density was done for diesel and NOME-20 blend at their respective optimum injection pressure. Higher BSFC, a slight decrease in BTE, and a sharp decrease in EGT and smoke density were recorded with NOME-20 blend. Emissions with NOME-20 blend were also compared with diesel emissions at their respective optimum injection pressures. Significant reductions in carbon monoxide, hydrocarbon, and oxides of nitrogen and increase in carbon-di-oxide were observed with NOME-20 blend. Hence, neem biodiesel has an environmental importance over diesel and shows a promising future.
The $X^{1}\Sigma ^{+}_{g}$X1Σg+ ground state of Mg2 studied by Fourier-transform spectroscopy
Authors: Knöckel H. , Rühmann S. , Tiemann E.
Published: March 2013

The \documentclass[12pt]{minimal}\begin{document}${\rm A}^1\Sigma _{\mathrm{u}}^+$\end{document}A1Σu+ - \documentclass[12pt]{minimal}\begin{document}${\rm X}^1\Sigma _{\mathrm{g}}^+$\end{document}X1Σg+ UV spectrum of Mg2 has been investigated with high resolution Fourier-transform spectroscopy. Mg2 vapor was created in a heat pipe. Various spectroscopic methods have been employed, such as conventional absorption spectroscopy with light from a broad band lamp and laser-induced fluorescence. The high resolution of the Fourier-transform spectrometer, together with computer aided evaluation methods of the spectra, yields precise transition frequencies. The new data and data available from earlier investigations are applied in direct potential fits of lower and upper electronic states. Various representations of potential energy curves for the ground state \documentclass[12pt]{minimal}\begin{document}${\rm X}^1\Sigma _{\mathrm{g}}^+$\end{document}X1Σg+ have been employed and their benefits in terms of smallest number of parameters are discussed. Scattering lengths are derived for the homonuclear isotopologues and compared with previous results.
Direct observation of back energy transfer in blue phosphorescent materials for organic light emitting diodes by time-resolved optical waveguide spectroscopy
Authors: Hirayama H. , Sugawara Y. , Miyashita Y. , Mitsuishi M. , Miyashita T.
Published: March 2013

We demonstrate a high-sensitive transient absorption technique for detection of excited states in an organic thin film by time-resolved optical waveguide spectroscopy. By using a laser beam as a probe light, we detect small change in the transient absorbance which is equivalent to 10−7 absorbance unit in a conventional method. This technique was applied to organic thin films of blue phosphorescent materials for organic light emitting diodes. We directly observed the back energy transfer from emitting guest molecules to conductive host molecules.
Applicability of the wide-band limit in DFT-based molecular transport calculations
Authors: Verzijl C. J. O. , Seldenthuis J. S. , Thijssen J. M.
Published: March 2013

Transport properties of molecular junctions are notoriously expensive to calculate with ab initio methods, primarily due to the semi-infinite electrodes. This has led to the introduction of different approximation schemes for the electrodes. For the most popular metals used in experiments, such as gold, the wide-band limit (WBL) is a particularly efficient choice. In this paper, we investigate the performance of different WBL schemes relative to more sophisticated approaches including the fully self-consistent non-equilibrium Green's function method. We find reasonably good agreement between all schemes for systems in which the molecule (and not the metal-molecule interface) dominates the transport properties. Moreover, our implementation of the WBL requires negligible computational effort compared to the ground-state density-functional theory calculation of a molecular junction. We also present a new approximate but efficient scheme for calculating transport with a finite bias. Provided the voltage drop occurs primarily inside the molecule, this method provides results in reasonable agreement with fully self-consistent calculations.
Site-specific analysis of dipole polarizabilities of heterogeneous systems: Iron-doped Sin (n = 1–14) clusters
Authors: Ma Li , Wang Jianguang , Wang Guanghou
Published: March 2013

Following the recent work of decomposing the total dipole moment and polarizability of a homogeneous system into site-specific contributions, we extend the study to the heterogeneous systems of iron-doped Sin (n = 1–14) clusters by introducing a weighting function. The structure-/shape- and size-specific aspects of the dipole moments and polarizabilities of SinFe (n = 1–14) clusters are analyzed and compared with pure silicon clusters. It is shown that the polarizabilities associated with the individual constituent atoms vary considerably with the structure/shape of the cluster and the location of the atom or site within a given structure. For atoms at peripheral sites, the polarizabilities are substantially larger than atoms at the interior sites, and the more peripheral an atom is, the larger is its polarizability. The polarizability of the Fe atom in SinFe clusters decreases as the cluster size increases. This is related to the position of Fe atom in SinFe clusters and indicates significant screening of the interior of the cluster by its surface. The correlation between the anisotropy of the total polarizability and the anisotropy of the cluster shape is also analyzed. Comparing with pure Sin clusters, the polarizabilities of Si atoms are increased after Fe atom doping. The structures are more compact for SinFe than the same sizes of Sin+1 clusters and the polarizabilities of SinFe are smaller than Sin+1 for the sizes of n = 7–14.
Mechanisms in the saturation behavior for low voltage cathodoluminescence
Authors: Shang Chunyu , Wang Xiuqin , Cheng Ziyong , Hou Zhiyao , Lin Jun
Published: March 2013

The saturation behavior in exciting power Pexcite is the specific characteristic in low voltage cathodoluminescence due to the high resistivity of the phosphor, causing the saturation behavior in field emission display. With the increasing of current density j, the saturation behavior in Pexcite directly results in the saturation of electron-hole (e-h) generation rate gnum. The e-h generation region X would shrink, resulting in the drastic increase of e-h concentration generation rate gcon, causing the decrease in probability ηet of an e-h pair exciting an activator. In addition, the radiative transition probability ηrad of an excited activator would be decreased due to the shrinkage of X and increase of temperature. To restrain the saturation behavior in low voltage cathodoluminescence, the ultimate method is to lower the resistivity of the phosphor. By introducing In2O3 conductive component into Y2O3:Eu3+ phosphor, restrained saturation behavior in cathodoluminescence of Y2O3:Eu3+ phosphor was effectively achieved.
Surface potential effect on excitons in AlGaN/GaN quantum well structures
Authors: Pozina G. , Hemmingsson C. , Amano H. , Monemar B.
Published: March 2013

AlGaN/GaN quantum well (QW) heterostructures grown by metalorganic chemical vapor deposition on sapphire and on free-standing GaN substrates have been studied by temperature dependent time-resolved photoluminescence. A dominant contribution of the exciton radiative lifetime is observed in homoepitaxial samples even at enhanced temperatures up to 100 K. The QW-related emission is found to be more sensitive to the near surface built-in electric field in the homoepitaxial samples, revealed as a red shift of the QW exciton energy with decreasing the cap layer thickness. Absence of such shift in the heteroepitaxial samples suggests, assuming a surface potential of 0.5 eV, an increased polarization field due to residual compressive stress.