bluuebunny/crossref_metadata_2025 huggingface dataset:
Complement‐mediated chronic inflammation is associated with diabetic microvascular complication
Authors: Fujita Takayuki , Hemmi Seiichiro , Kajiwara Mamiko , Yabuki Minako , Fuke Yoshinobu , Satomura Atsushi , Soma Masayoshi
Published: December 2012

Background

Chronic inflammation is characteristic of type 2 diabetes mellitus (T2DM). Obesity‐activated adipocytes release adipocytokines, which induce the secretion of proinflammatory cytokines, resulting in vascular endothelial dysfunction and organ injury. C3a is a candidate to induce tissue inflammation.

Methods

We investigated the association between diabetic microangiopathy and complement‐mediated inflammation in 32 obese T2DM patients and 32 normal donors. Plasma levels of complement components and their activation intermediates were examined and related to the level of complication. An incubation study of post‐prandial serum was carried out to measure the in vitro production of acylation stimulating protein (ASP/C3a desArg) by chylomicron.

Results

Plasma levels of C3, C4, factor B, iC3b, Bb, and ASP were significantly increased in T2DM patients. Levels of C4d and membrane attack complex (C5b‐9) were not significantly elevated. The activation rate of these factors indicated that only the early phase of alternative complement pathway was excessively activated. A statistical study revealed close correlation between ASP, body mass index, and highly sensitive C‐reactive protein. Plasma ASP was significantly increased in the macroalbuminuric and proliferative retinopathy patient groups. An incubation study revealed that ASP was produced after the in vitro incubation of post‐prandial serum from a T2DM patient with hyperchylomicronaemia.

Conclusions

Activation of the alternative complement pathway occurs in obese T2DM patients and is enhanced in the post‐prandial hyperchylomicronic condition, which induces overproduction of ASP and C3a‐mediated tissue inflammation. Therefore, complement‐mediated inflammation may contribute to the acceleration of diabetic microangiopathy in addition to the development of macroangiopathy. Copyright © 2012 John Wiley & Sons, Ltd.
Foliar δ13C response patterns along a moisture gradient arising from genetic variation and phenotypic plasticity in grassland species of Inner Mongolia
Authors: Liu Yanjie , Niu Haishan , Xu Xingliang
Published: December 2012

Plants depend upon both genetic differences and phenotypic plasticity to cope with environmental variation over different timescales. The spatial variation in foliar δ13C levels along a moisture gradient represents an overlay of genetic and plastic responses. We hypothesized that such a spatial variation would be more obvious than the variation arising purely from a plastic response to moisture change. Leymus chinensis and Stipa spp. were sampled from Inner Mongolia along a dry‐wet transect, and some of these species were transplanted to an area with a moisture gradient. For Stipa spp., the slope of foliar δ13C and mean annual precipitation along the transect was significantly steeper than that of foliar δ13C and mean annual precipitation after the watering treatment. For L. chinensis, there was a general decreasing trend in foliar δ13C under the different (increasing) watering levels; however, its populations showed an irregular relationship between foliar δ13C and moisture origin. Therefore, support for our hypothesis was obtained from Stipa spp., but not from L. chinensis.
The effect of turbidity on recognition and generalization of predators and non‐predators in aquatic ecosystems
Authors: Chivers Douglas P. , Al‐Batati Fawaz , Brown Grant E. , Ferrari Maud C. O.
Published: December 2012

Recent anthropogenic activities have caused a considerable change in the turbidity of freshwater and marine ecosystems. Concomitant with such perturbations are changes in community composition. Understanding the mechanisms through which species interactions are influenced by anthropogenic change has come to the forefront of many ecological disciplines. Here, we examine how a change in the availability of visual information influences the behavior of prey fish exposed to potential predators and non‐predators. When fathead minnows,Pimephales promelas, were conditioned to recognize predators and non‐predators in clear water, they showed a highly sophisticated ability to distinguish predators from non‐predators. However, when learning occurred under conditions of increased turbidity, the ability of the prey to learn and generalize recognition of predators and non‐predators was severely impaired. Our work highlights that changes at the community level associated with anthropogenic perturbations may be mediated through altered trophic interactions, and highlights the need to closely examine behavioral interactions to understand how species interactions change.
Prooxidant‐induced c‐Src/nuclear factor kappa B‐coupled signalling in sensory ganglia mediates cutaneous hyperalgesia
Authors: Igwe O.J.
Published: December 2012

Background

Persistent pain resulting from peripheral injury/inflammation is associated with altered sensitivity to cutaneous stimuli, which can manifest as hyperalgesia. The role of oxidant stress in the development, progression and maintenance of hyperalgesia is still not understood. Furthermore, there appears to be a relationship between c‐Src kinase in the pain pathway and oxidative stress.

Methods

We have used a novel prooxidant inflammatory pain model that involves potassium peroxychromate (PPC), a unique prooxidant that produces the same reactants as activated phagocytes. This model was used to investigate the role of oxidant‐activated c‐Src in mediating hyperalgesia. We compared the effects of PP2 (a Src family kinase inhibitor) and c‐Src siRNA on behavioural hyperalgesia with sodium stibogluconate (SSG) (a non‐receptor tyrosine phosphatase inhibitor) and AG 1478 (a receptor tyrosine kinase inhibitor).

Results

PP2 and c‐Src siRNA attenuated PPC‐induced thermal hyperalgesia, while SSG enhanced it. AG 1478 had no effect. PP2 decreased the levels of IL‐1β, c‐Src/inhibitory kappa B kinase complex formed and prostaglandin E2 produced in the dorsal root ganglia (DRG) ipsilateral to the inflamed paw, while SSG increased the levels of these parameters. c‐Src siRNA decreased Src expression and activity in the DRG ipsilateral to the inflamed paw.

Conclusions

These results confirm that prooxidant‐activated c‐Src plays a role in initiating and maintaining hyperalgesia by regulating a stimulus‐response coupling between the inflamed tissue and the DRG in the pain pathway. Our data also suggest that oxidant‐induced dysregulation of c‐Src/nuclear factor kappa B coupling may contribute to our understanding of the transition from acute to chronic dysfunctional pain state seen in many human diseases.
Doppler study of the fetal vertebral and middle cerebral arteries in fetuses with normal and increased umbilical artery resistance indices
Authors: Morales Roselló José , Hervás Marín David , Perales Marín Alfredo , López Fraile Sara
Published: December 2012

Objective:

To compare the brain sparing mechanism of the fetal vertebral artery (VA), with the one of the middle cerebral artery (MCA) in fetuses with increased umbilical artery (UA) Doppler impedance.

Method:

We retrospectively studied 1084 Doppler examinations of the VA, MCA and UA performed in 1084 fetuses between 19 and 41 week of gestation. These were divided into 3 groups according to the UA resistance index (UA RI): group 1: UA RI < 95th percentile (N = 965), group 2: UA RI > 95th percentile (N = 111) and group 3: absent UA diastolic flow (N = 8). Afterwards, values were converted into multiples of the median (MoM), and means and standard deviations were calculated. Finally, Kruskal‐Wallis tests and box and whiskers charts were applied to evaluate differences.

Results:

For both, the VA RI and MCA RI, no differences were seen among the groups of fetuses who maintained diastolic flow in the UA. However, the VA RI and MCA RI were lower when the UA diastolic flow was absent.

Conclusion:

The VA and MCA work in unison, decreasing impedances only when UA flow is severely affected. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013
Improving cellular uptake and in vivo tumor suppression efficacy of liposomal oligonucleotides by urea as a chemical penetration enhancer
Authors: Saffari Mostafa , Tamaddon Ali Mohammad , Shirazi Farshad Hoseini , Oghabian Mohammad Ali , Moghimi Hamid Reza
Published: December 2012

Background

Liposomes are among the most widely used carriers for the delivery of antisense oligonucleotides (AsODNs) to intracellular targets. Although different strategies have been employed, the question of how to improve liposomal uptake and enhance the release of AsODN into cytoplasm still remains to be answered with respect to the use of a safe, easy and economic method. In the present study, the possibility of enhancing such processes at cellular and animal levels using urea as a penetration enhancer was investigated.

Methods

To perform this investigation, a cationic liposome containing an AsODN against protein kinase (PKC)‐α was prepared, and the effect of urea on its cellular internalization and the related sequence‐specific inhibition of gene expression in human lung adenocarcinoma A549 cells were investigated by flow cytometry and the reverse transcriptase‐polymerase chain reaction, respectively. In in vivo studies, a xenograft lung tumor was established in nude mice by A549 cells and the enhancement effect of urea toward the effects of liposomal AsODN on tumor growth was investigated.

Results

Cellular studies revealed that urea treatment increases liposomal uptake and the release of AsODN into the cytoplasm by approximately 40%. Sequence‐specific inhibition of target gene PKC‐α expression was also increased by approximately two‐fold by urea at 200–300 nM AsODN. In animal studies, urea significantly decreased the tumor volume (approximately 40%) and increased its doubling time from approximately 13 days to 17 days.

Conclusions

Urea, and possibly other membrane fluidizers, could be regarded as penetration enhancers for liposomal AsODN delivery and may improve the therapeutic effect of these gene‐therapy vectors at both cellular and animal levels. Copyright © 2012 John Wiley & Sons, Ltd.
Double approach operation for large extracompartmental proximal thigh tumors
Authors: Papanastassiou Ioannis D. , Karypidis Dimitrios , Kokkalis Zinon T. , Gerochristou Maria A. , Demertzis Nikolaos
Published: December 2012

Resection of large femoral triangle tumors that invade the bone (or vice versa) still remains a challenge. A lateral‐only approach would hinder dissection of the mass, away from the femoral vessels, while an iliofemoral‐only type of approach would make bone resection and megaprosthetic reconstruction very arduous. The authors describe a two‐stage, one‐position operation via a double surgical approach: the first stage is comprised by an iliofemoral approach and dissection of the femoral vessels, followed by proximal femoral resection and reconstruction stage. One illustrative case is presented along with the authors overall experience. We believe that this operation facilitates wide tumor resection in a safe and step‐wise manner, as not to add to the morbidity of the procedure. J. Surg. Oncol. 2013;107:673–679. © 2012 Wiley Periodicals, Inc.
Secondary cytoreductive surgery and peri‐operative intraperitoneal chemotherapy for peritoneal recurrence of colorectal and appendiceal peritoneal carcinomatosis following prior primary cytoreduction
Authors: Klaver Yvonne L.B. , Chua Terence C. , Verwaal Victor J. , de Hingh Ignace H.J.T. , Morris David L.
Published: December 2012

Purpose

Primary cytoreductive surgery (CRS) and peri‐operative intraperitoneal chemotherapy (PIC) is the only curative option for patients with colorectal cancer peritoneal carcinomatosis (PC). A significant proportion of patients develop peritoneal recurrence. Outcomes of patients undergoing secondary CRS and PIC for recurrent PC were examined.

Methods

All patients undergoing second procedures with curative intent for recurrent appendiceal or colorectal cancer PC in three centers were included. Patients with recurrent pseudomyxoma peritonei (PMP) were excluded. Morbidity and mortality, overall survival, and disease‐free survival were primary outcome parameters.

Results

The study included 18 patients (13 colorectal and 5 appendiceal cancer). At primary CRS, mean Peritoneal Cancer Index (PCI) was 9.1. In 13 patients complete resection was achieved. Median time to recurrence was 14 months (range: 1–33). At secondary CRS, mean PCI was 6.3 and CRS was complete in 13 patients. There was no 30‐day mortality and 1‐ and 2‐year survival were 74% and 50%, respectively. In 14 patients a recurrence after the second procedure was diagnosed.

Conclusions

A secondary CRS for recurrent colorectal or appendiceal cancer PC is safe and feasible, however, relapse is frequent. Further investigations are required to critically assess the efficacy of a secondary procedure and to define optimal patient selection criteria in the era of effective modern chemotherapy. J. Surg. Oncol. 2013;107:585–590. © 2012 Wiley Periodicals, Inc.
Malnutrition and pancreatic surgery: Prevalence and outcomes
Authors: La Torre Marco , Ziparo Vincenzo , Nigri Giuseppe , Cavallini Marco , Balducci Genoveffa , Ramacciato Giovanni
Published: December 2012

Background

Pancreatic surgery is associated with severe postoperative morbidity. Identification of patients at high risk may provide a way to allocate resources objectively and focus care on those patients in greater need. The Authors evaluate the prevalence of malnutrition and its effect on the postoperative morbidity of patients undergoing pancreatic surgery for malignant tumors.

Methods

Data were collected from 143 patients who had undergone pancreatic resection for cancer. Prevalence of malnutrition was evaluated by several validated screening tools and correlated to the incidence of surgical site infection, overall morbidity, mortality, and hospital stay.

Results

Overall, 88% of patients were at medium‐high risk of malnutrition. Patients at high risk of malnutrition presented a fourfold longer postoperative hospitalization period and a higher morbidity rate (53.2%) than those patients at low risk of malnutrition. Malnutrition, evaluated by MUST and NRI, was an independent predictor of overall morbidity using multivariate analysis (P = 0.00145, HR = 2.6581, 95% CI = 1.3589–8.5698, and P = 0.07129, HR = 1.9953, 95% CI = 0.9723–13.548, respectively).

Conclusion

Malnutrition is a relevant predictor of post‐operative morbidity and mortality after pancreatic surgery. Patients underwent pancreatic resection for malignant tumors are usually malnourished. Preoperative malnutrition screening is mandatory in order to assess the risk and to treat the malnutrition. J. Surg. Oncol. 2013;107:702–708. © 2012 Wiley Periodicals, Inc.
Management of primary hepatopancreatobiliary small cell carcinoma
Authors: Groeschl Ryan T. , Christians Kathleen K. , Turaga Kiran K. , Gamblin T. Clark
Published: December 2012

Background and Objectives

Primary small cell carcinomas (SCC) of the pancreas, liver, gallbladder, and bile ducts have only been described in case reports. We hypothesized that surgical treatment was associated with improved overall survival (OS) for patients with localized hepatopancreatobiliary SCC.

Methods

The Surveillance, Epidemiology, and End‐Results (SEER) database was queried for patients with SCC from 1998 to 2008. Survival was analyzed with Cox proportional hazards models.

Results

Eighty‐five patients had nonmetastatic hepatopancreatobiliary SCC and operative treatment data. Hepatic SCC was associated with a 2 month median OS, and no patient underwent surgery. Stage‐adjusted median OS for pancreatobiliary SCC patients undergoing resection (19 months, 95% confidence interval [CI]: 10–42 months) was greater than those who were not resected (8 months, 95% CI: 4–12 months, P = 0.0052). Both surgical resection (hazard ratio [HR]: 0.42, 95% CI: 0.29–0.63, P < 0.001) and administration of radiation therapy (HR: 0.50, 95% CI: 0.35–0.71, P < 0.001) independently predicted prolonged OS in adjusted models.

Conclusion

Surgical resection was associated with prolonged survival for patients with localized pancreatic, gallbladder, and biliary primaries. While we recognize several biases inherent in a population‐based study, these results provide insight into the survival that can be achieved with surgical resection of SCC in these specific locations. J. Surg. Oncol. 2013;107:692–695. © 2012 Wiley Periodicals, Inc.
Intentions for bilateral mastectomy among newly diagnosed breast cancer patients
Authors: King Lesley , O'Neill Suzanne C. , Spellman Elizabeth , Peshkin Beth N. , Valdimarsdottir Heiddis , Willey Shawna , Leventhal Kara Grace , DeMarco Tiffani , Nusbaum Rachel , Feldman Elizabeth , Jandorf Lina , Schwartz Marc D.
Published: December 2012

Background

Recent trends suggest that bilateral mastectomy (BM) is on the rise among women diagnosed with unilateral breast cancer. Few studies have investigated the factors associated with the decision to have more aggressive surgery among young, high risk patients.

Methods

As part of a larger study, 284 women aged 50 and under completed an initial survey within 6 weeks of a breast cancer diagnosis. We assessed sociodemographics, medical and family history variables, treatment recommendations, preferences and concerns, distress, perceived risk, knowledge, and neuroticism. We used multiple regression with backward entry to assess the relationship between these variables and our outcomes of decisional conflict and intentions for BM.

Results

Higher decisional conflict was associated with being less educated, unmarried, more anxious and less likely to have received a surgical recommendation. Preference for BM was associated with higher neuroticism, perceived risk for contralateral breast cancer, pre‐testing risk of carrying a BRCA1/2 mutation, having received either a surgical recommendation (vs. no recommendation), and lower preference for lumpectomy.

Conclusions

For younger women, a surgical recommendation is associated with lower decisional conflict and stronger intention for BM. Results highlight the importance of effective risk communication and decision support between a woman and her surgeon. J. Surg. Oncol. 2013;107:772–776. © 2012 Wiley Periodicals, Inc.
Flow‐through immobilized enzyme reactors based on monoliths: II. Kinetics study and application
Authors: Vlakh Evgenia G. , Tennikova Tatiana B.
Published: December 2012

In the last decade, the application of monolithic materials has rapidly expanded to the realization of flow‐through bioconversion processes. Up to these days, different classes of enzymes such as hydrolases, lyases, and oxidoreductases have been immobilized on organic, inorganic, or hybrid monolithic materials to prepare the effective flow‐through enzymes reactors for application in proteomics, biotechnology, pharmaceutics, organic synthesis, and biosensoring. Current review describes the results of kinetic study and specialties of flow‐through immobilized enzyme reactors based on the existing monolithic materials.
Formal Approaches to Particle Meaning
Authors: McCready Eric
Published: December 2012

This paper considers the formal analysis of particles. It first defines the notion of particle in question, then looks at particles in English, German and Japanese and some formal analyses that have been proposed for them. Finally, it examines some general questions related to particle meaning involving meaning types and restrictions on distribution.
Reflections on Phonetic Convergence: Speech Perception does not Mirror Speech Production
Authors: Pardo Jennifer S.
Published: December 2012

Since the beginnings of speech research, the issue of variability has been a central topic in the field. Until recently, solutions to this problem have focused mainly on resolving linguistic forms from variable acoustic realizations, with little systematic consideration of talker variability or social settings. However, acoustic‐phonetic variability within and between talkers does not arise by chance – such variation is attributable to a variety of causes including talker physiology, dialect, affect, and social/situational factors. Studies of conversational interaction demonstrate the influence of situational factors on many aspects of spoken communication. In particular, interacting talkers converge and diverge in acoustic‐phonetic form over the course of a single conversational setting. Although phonetic convergence likely reflects a close connection between speech perception and production, it is not an automatic consequence of priming mechanisms or a mirror neuron system. In studies of the neural activity associated with speech perception, it is increasingly clear that utterances are processed in separate dorsal and ventral cortical streams, one that is part of the self‐regulation of spoken utterances, and another that is part of conceptual understanding. Links between perception and production appear to be part of the self‐regulatory system that participates in speech production control monitoring, which makes this system a likely candidate for talker control of acoustic‐phonetic variability. Whether talkers converge or diverge depends on multiple aspects of the social setting, which have a much greater influence on the form of phonetic expression than automatic links or mirror mechanisms.
Bifunctional Nanoparticles Constructed Using One‐Pot Encapsulation of a Fluorescent Polymer and Magnetic (Fe3O4) Nanoparticles in a Silica Shell
Authors: Lee Chang‐Soo , Chang Hee Hyun , Bae Pan‐Kee , Jung Juyeon , Chung Bong Hyun
Published: December 2012

Integration of biocompatible silica with a fluorescent polymer (PDDF) and superparamagnetic iron oxide nanoparticles (Fe3O4) to form uniform core–shell nanostructures has the great potential to form particles for use in multimodal bioimaging applications. Core–shell nanoparticles (PDDF/Fe3O4@SiO2) exhibit fluorescent and magnetic properties that are favorable for their use in magnetic separation and guiding applications, as well as optical and magnetic resonance (MR) imaging capabilities. With the biological analysis in an in vitro intracellular permeation and cytotoxicity test, chemical conjugation of the surface using folic acid (FA) molecules can provide the nanoparticles with cell‐targeting properties, localizing the nanoparticles to folate receptors (FRs) on target KB cells that over‐express the FRs.

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Chain Microstructure, Crystallization, and Morphology of Olefinic Blocky Copolymers
Authors: Tong Zai‐Zai , Huang Jie , Zhou Bing , Xu Jun‐Ting , Fan Zhi‐Qiang
Published: December 2012

The chain microstructure, crystallization, and morphology of three olefinic blocky copolymers (OBCs) are compared. The weight percentage of the hard block and the octene content in it are calculated from the 13C NMR spectra with a two‐site first‐order Markovian model. The lengths of the hard blocks are compared from the melting and crystallization behaviors. The remarkable difference between the crystallinity measured by DSC, and wide‐angle X‐ray diffraction (WAXD) indicates the presence of partially ordered phases. Small angle X‐ray scattering (SAXS) shows that the partially ordered phases in OBC‐A are mainly located at the interface between the crystalline and amorphous phases, but exist as separated microdomains in OBC‐B. As the hard block becomes shorter, there are also more, separated partially ordered phases in OBC‐C. Spherulites are observed in all OBCs by POM and the size of the spherulites decreases in the order: OBC‐A > OBC‐B > OBC‐C. TEM shows that spherulites are poorly developed in a thin film of OBC‐B.
Semi‐Random Two‐Acceptor Polymers: Elucidating Electronic Trends Through Multiple Acceptor Combinations
Authors: Burkhart Beate , Khlyabich Petr P. , Thompson Barry C.
Published: December 2012

Four semi‐random poly(3‐hexylthiophene) (P3HT)‐based donor/acceptor copolymers each containing two different acceptor monomers with a total acceptor content of 15% and a constant 1:1 acceptor ratio are synthesized (P3HTT‐BTD‐DPP, P3HTT‐TP‐DPP, P3HTT‐TP‐TPD, and P3HTT‐BTD‐TPD). All four polymers have considerably broadened absorption spectra compared with P3HT and the shape of the absorption profile and the bandgap of the two‐acceptor copolymers can be predicted through a linear combination of absorption profiles of the respective one‐acceptor semi‐random copolymers. Important properties of P3HT, such as semicrystallinity, high hole mobility, and favorable mixing with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) in solar cells at low fullerene ratios are retained for all of the two‐acceptor copolymers. The highest occupied molecular orbital (HOMO) energies of two‐acceptor copolymers are, in almost all cases, higher than the lowest measured value for the corresponding “parent” one‐acceptor polymers and are in some cases higher than the values for both. The HOMO energies correlate in a generally linear fashion with the Voc measured in solar cells. Efficiencies of up to 3% emphasize the promise of this class of polymers.
Analytic regularity and nonlinear approximation of a class of parametric semilinear elliptic PDEs
Authors: Hansen Markus , Schwab Christoph
Published: December 2012

We investigate existence and regularity of a class of semilinear, parametric elliptic PDEs with affine dependence of the principal part of the differential operator on countably many parameters. We establish a priori estimates and analyticity of the parametric solutions. We establish summability results of coefficient sequences of polynomial chaos type expansions of the parametric solutions in terms of tensorized Taylor‐, Legendre‐ and Chebyshev polynomials on the infinite‐dimensional parameter domain. We deduce rates of convergence for N term truncated approximations of expansions of the parametric solution. We also deduce spatial regularity of the solution, and establish convergence rates of N‐term discretizations of the parametric solutions with respect to these polynomials in parameter space and with respect to a multilevel hierarchy of finite element spaces in the spatial domain of the PDE.
The genus of HNN‐extensions
Authors: de Bessa Vagner Rodrigues , Zalesskii Pavel
Published: December 2012

We find a bound on the genus of an HNN‐extension HNN(K, A, f) with a finite base group K. We also give sufficient conditions when the genus is 1, i.e. when HNN(K, A, f) is determined by its profinite completion up to isomorphism with respect to the family of all virtually free groups.
Organic Nonvolatile Resistive Switching Memory Based on Molecularly Entrapped Fullerene Derivative within a Diblock Copolymer Nanostructure
Authors: Jo Hanju , Ko Jieun , Lim Jung Ah , Chang Hye Jung , Kim Youn Sang
Published: December 2012

Organic nonvolatile resistive switching memory is developed via selective incorporation of fullerene derivatives, [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM), into the nanostructure of self‐assembled poly(styrene‐b‐methyl methacrylate) (PS10‐b‐PMMA130) diblock copolymer. PS10‐b‐PMMA130 diblock copolymer provides a spatially ordered nanotemplate with a 10‐nm PS nanosphere domain surrounded by a PMMA matrix. Spin casting of the blend solution of PS10‐b‐PMMA130 and PCBM spontaneously forms smooth films without PCBM aggregation in which PCBM molecules are incorporated within a PS nanosphere domain of PS10‐b‐PMMA130 nanostructure by preferential intermixing propensity of PCBM and PS. Based on the well‐defined PS10‐b‐PMMA130/PCBM nanostructure, resistive random access memory (ReRAM) exhibits significantly improved bipolar‐switching behavior with stable and reproducible properties at low operating voltages (RESET at 1.3 V and SET at −1.5 V) under ambient conditions. Finally, flexible memory devices are achieved using a nanostructured PS10‐b‐PMMA130/PCBM composite in which no significant degradation of electrical properties is observed before and after bending.
Near‐Infrared Responsive Conjugated Polymers to 1.5 μm and Beyond: Synthesis and Electrochromic Switching Application
Authors: Tang Tao , Ding Guoqiang , Lin Tingting , Chi Hong , Liu Chen , Lu Xuehong , Wang FuKe , He Chaobin
Published: December 2012

Azulene‐containing conjugated polymers with near‐infrared absorption up to 1.5 μm and beyond are achieved by treating with trifluoroacetic acid (TFA). Density functional theory calculations reveal that the near‐infrared absorption arises from a strong intramolecular charge transfer transition on the polymer backbone, and the near‐infrared absorption can be tuned by the degree of protonation. Furthermore, TFA treated polymers show a ten‐fold enhancement in electrochromic contrast and significantly improved switching stability, suggesting that these polymers are promising candidates for fabrication of the first generation organic near‐infrared devices.
Phylogenetic composition and distribution of picoeukaryotes in the hypoxic northwestern coast of the Gulf of Mexico
Authors: Rocke Emma , Jing Hongmei , Liu Hongbin
Published: December 2012

Coastal marine hypoxic, or low‐oxygen, episodes are an increasing worldwide phenomenon, but its effect on the microbial community is virtually unknown by far. In this study, the community structure and phylogeny of picoeukaryotes in the Gulf of Mexico, which are exposed to severe hypoxia in these areas was explored through a clone library approach. Both oxic surface waters and suboxic bottom waters were collected in August 2010 from three representative stations on the inner Louisiana shelf near the Atchafalaya and Mississippi River plumes. The bottom waters of the two more western stations were much more hypoxic in comparison to those of the station closest to the Mississippi River plume, which were only moderately hypoxic. A phylogenetic analysis of a total 175 sequences, generated from six 18S rDNA clone libraries, demonstrated a clear dominance of parasitic dinoflagellates from Marine alveolate clades I and II in all hypoxic waters as well as in the surface layer at the more western station closest to the Atchafalaya River plume. Species diversity was significantly higher at the most hypoxic sites, and many novel species were present among the dinoflagellate and stramenopile clades. We concluded that hypoxia in the Gulf of Mexico causes a significant shift in picoeukaryote communities, and that hypoxia may cause a shift in microbial food webs from grazing to parasitism.
Single‐cell analysis of cell viability after a biocide treatment unveils an absence of positive correlation between two commonly used viability markers
Authors: Ducret Adrien , Dukan Sam
Published: December 2012

Discrimination among viable/active or dead/inactive cells in a microbial community is a vital question to address issues on ecological microbiology or microbiological quality control. It is commonly assumed that metabolically active cells (ChemchromeV6 [CV6] procedure) correspond to viable cells (direct viable count procedure [DVC]), although this assumption has never been demonstrated and is therefore a matter of debate. Indeed, simultaneous determination of cell viability and metabolic activity has never been performed on the same cells. Here, we developed a microfluidic device to investigate the viability and the metabolic activity of Escherichia coli cells at single‐cell level. Cells were immobilized in a flow chamber in which different solutions were sequentially injected according to different scenarios. By using time‐lapse microscopy combined with automated tracking procedures, we first successfully assessed the ability of cells to divide and their metabolic activity at single‐cell level. Applying these two procedures on the same cells after a hypochlorous acid (HOCl) treatment, we showed that the ability of cells to divide and their metabolic activity were anticorrelated. These results indicate that the relation between CV6 uptake and cell viability may be partially incorrect. Care must be taken in using the terms “CV6‐positive” and “viable” synonymously.
An Overview of ELECTRE Methods and their Recent Extensions
Authors: Figueira José Rui , Greco Salvatore , Roy Bernard , Słowiński Roman
Published: December 2012

We present main characteristics of ELECTRE (ELimination Et Choix Traduisant la REalité ‐ ELimination and Choice Expressing the REality) family methods, designed for multiple criteria decision aiding. These methods use as a preference model an outranking relation on the set of actions—it is constructed in result of concordance and nondiscordance tests involving a specific input preference information. After a brief description of the constructivist conception in which the ELECTRE methods are inserted, we present the main features of these methods. We discuss such characteristic features as the possibility of taking into account positive and negative reasons in the modelling of preferences, without requiring commensurable performance scales; the use of discriminating thresholds for taking into account the imperfect knowledge of data; the absence of systematic compensation between ‘gains’ and ‘losses’. The main weaknesses are also presented. Then, some aspects related to new developments are outlined. These are related to some new methodological developments, new procedures, axiomatic analysis, software tools and several other aspects. This paper is an updated version of a chapter published by the authors under the title ‘Electre Methods: Main Features and Recent Developments’ in C. Zopounidis and P. Pardalos (Editors): Handbook of Multicriteria Analysis, Springer, Berlin 2010, pp. 51–89. Copyright © 2012 John Wiley & Sons, Ltd.
A Simulated Annealing Algorithm for Noisy Multiobjective Optimization
Authors: Mattila Ville , Virtanen Kai , Hämäläinen Raimo P.
Published: December 2012

This paper presents a new simulated annealing (SA) algorithm for noisy multiobjective optimization with continuous decision variables. A novel feature of the algorithm in the context of SA is that the performance of a candidate solution is determined by estimating the probabilities that the candidate is dominated by the current non‐dominated solutions. The sum of these probabilities provides a scalar performance measure that is used to determine the acceptance of the candidate as the current solution and whether the candidate is inserted into the non‐dominated set. The second novel feature of the algorithm is the technique utilized for generating candidate solutions. Empirical probability distributions for sampling the new values of the decision variables are constructed on the basis of the values of the variables in the current non‐dominated set. Thus, the information contained by the non‐dominated set is utilized to improve the quality of the generated candidates, whereas this information is ignored in the existing multiobjective SA algorithms. The proposed algorithm is compared with a reference state‐of‐the‐art evolutionary algorithm as well as two other SA algorithms in numerical experiments involving 16 problems from commonly applied test suites. The proposed algorithm performs as good or better compared with the reference algorithms in majority of the experiments and therefore represents a promising solution method for noisy multiobjective optimization problems. Copyright © 2012 John Wiley & Sons, Ltd.
The Prevalence and Performance Impact of Synergies in the Plural Form
Authors: Meiseberg Brinja
Published: December 2012

Using the plural form helps franchised chains cope with the four ‘franchising imperatives’—system growth, chain uniformity, local responsiveness, and systemwide adaptation. Yet, despite the obvious importance of chain composition, empirical research on synergies in the plural form is largely absent, and insights on performance implications of the plural form are equally scarce. Consequently, with detailed data from 122 chains, this paper provides what is ostensibly the first in‐depth examination of the prevalence and performance effects of synergies that franchisors actually achieve by using the plural form. The study concludes with managerial implications for governance design in franchised chains. Copyright © 2012 John Wiley & Sons, Ltd.
In vitro maturation of oocytes alters gene expression and signaling pathways in bovine cumulus cells
Authors: Salhab Mohamad , Dhorne‐Pollet Sophie , Auclair Sylvain , Guyader‐Joly Catherine , Brisard Daphné , Dalbies‐Tran Rozenn , Dupont Joelle , Ponsart Claire , Mermillod Pascal , Uzbekova Svetlana
Published: December 2012

In vitro maturation (IVM) of immature oocytes is widely used in assisted reproduction technologies in cattle, and is increasingly used to treat human infertility. The development competence of IVM oocytes, however, is lower than preovulatory, in vivo‐matured oocytes. During maturation, cumulus cells (CC) are metabolically coupled with an oocyte and support the acquisition of its developmental potential. Our objective was to identify genes and pathways that were affected by IVM in bovine CC. Microarray transcriptomic analysis of CC enclosing in vitro‐ or in vivo‐mature oocytes revealed 472 differentially expressed genes, including 28% related to apoptosis, correlating with twofold higher cell death after IVM than in vivo, as detected by TUNEL. Genes overexpressed after IVM were significantly enriched in functions involved in cell movement, focal adhesion, extracellular matrix function, and TGF‐beta signaling, whereas under‐expressed genes were enriched in regulating gene expression, energy metabolism, stress response, and MAP kinases pathway functions. Differential expression of 15 genes, including PAG11 (increased) and TXNIP (decreased), which were never detected in CC before, was validated by real‐time RT‐PCR. Moreover, protein quantification confirmed the lower abundance of glutathione S‐transferase A1 and prostaglandin G/H synthase 2, and the higher abundance of hyaluronan synthase 2 and SMAD4, a member of TGF‐beta pathway, in CC after IVM. Phosphorylation levels of SMAD2, MAPK3/1, and MAPK14, but not MAPK8, were higher after IVM that in vivo. In conclusion, IVM provokes the hyper‐activation of TGF‐beta and MAPK signaling components, modifies gene expression, leads to increased apoptosis in CC, and thus affects oocyte quality. Mol. Reprod. Dev. © 2012 Wiley Periodicals, Inc.
Improved first‐pass spiral myocardial perfusion imaging with variable density trajectories
Authors: Salerno Michael , Sica Christopher , Kramer Christopher M. , Meyer Craig H.
Published: December 2012

Purpose

To develop and evaluate variable‐density spiral first‐pass perfusion pulse sequences for improved efficiency and off‐resonance performance and to demonstrate the utility of an apodizing density compensation function (DCF) to improve signal‐to‐noise ratio (SNR) and reduce dark‐rim artifact caused by cardiac motion and Gibbs Ringing.

Methods

Three variable density spiral trajectories were designed, simulated, and evaluated in 18 normal subjects, and in eight patients with cardiac pathology on a 1.5T scanner.

Results

By using a DCF, which intentionally apodizes the k‐space data, the sidelobe amplitude of the theoretical point spread function (PSF) is reduced by 68%, with only a 13% increase in the full‐width at half‐maximum of the main‐lobe when compared with the same data corrected with a conventional variable‐density DCF, and has an 8% higher resolution than a uniform density spiral with the same number of interleaves and readout duration. Furthermore, this strategy results in a greater than 60% increase in measured SNR when compared with the same variable‐density spiral data corrected with a conventional DCF (P < 0.01). Perfusion defects could be clearly visualized with minimal off‐resonance and dark‐rim artifacts.

Conclusion

Variable‐density spiral pulse sequences using an apodized DCF produce high‐quality first‐pass perfusion images with minimal dark‐rim and off‐resonance artifacts, high SNR and contrast‐to‐noise ratio, and good delineation of resting perfusion abnormalities. Magn Reson Med 70:1369–1379, 2013. © 2012 Wiley Periodicals, Inc.
Turbo fast three‐dimensional carotid artery black‐blood MRI by combining three‐dimensional MERGE sequence with compressed sensing
Authors: Li Bo , Dong Li , Chen Bin , Ji Shuangxi , Cai Wenchao , Wang Ye , Zhang Jue , Zhang Zhaoqi , Wang Xiaoying , Fang Jing
Published: December 2012

Purpose

In this study, we sought to investigate the feasibility of turbo fast three‐dimensional (3D) black‐blood imaging by combining a 3D motion‐sensitizing driven equilibrium rapid gradient echo sequence with compressed sensing.

Methods

A pseudo‐centric phase encoding order was developed for compressed sensing‐3D motion‐sensitizing driven equilibrium rapid gradient echo to suppress flow signal in undersampled 3D k‐space. Nine healthy volunteers were recruited for this study. Signal‐to‐tissue ratio, contrast‐to‐tissue ratio (CTR) and CTR efficiency (CTReff) between fully sampled and undersampled images were calculated and compared in seven subjects. Moreover, isotropic high resolution images using different compressed sensing acceleration factors were evaluated in two other subjects.

Results

Wall‐lumen signal‐to‐tissue ratio or CTR were comparable between the undersampled and the fully sampled images, while significant improvement of CTReff was achieved in the undersampled images. At an isotropic high spatial resolution of 0.7 × 0.7 × 0.7 mm3, all undersampled images exhibited similar level of the flow suppression efficiency and the capability of delineating outer vessel wall boundary and lumen‐wall interface, when compared with the fully sampled images.

Conclusion

The proposed turbo fast compressed sensing 3D black‐blood imaging technique improves scan efficiency without sacrificing flow suppression efficiency and vessel wall image quality. It could be a valuable tool for rapid 3D vessel wall imaging. Magn Reson Med 70:1347–1352, 2013. © 2012 Wiley Periodicals, Inc.
Arrhythmia insensitive rapid cardiac T1 mapping pulse sequence
Authors: Fitts Michelle , Breton Elodie , Kholmovski Eugene G. , Dosdall Derek J. , Vijayakumar Sathya , Hong Kyung P. , Ranjan Ravi , Marrouche Nassir F. , Axel Leon , Kim Daniel
Published: December 2012

Purpose

To develop an arrhythmia‐insensitive rapid (AIR) cardiac T1 mapping pulse sequence for quantification of diffuse fibrosis.

Methods

An arrhythmia‐insensitive cardiac T1 mapping pulse sequence was developed based on saturation recovery T1 weighting, which is inherently insensitive to heart rate and rhythm, and two single‐shot balanced steady‐state free precession image acquisitions with centric k‐space ordering, where T1 calculation is inherently insensitive to T2 effects. Its performance against conventional cardiac T1 mapping based on inversion recovery (i.e., MOLLI) is compared. Phantom experiments (T1 ranging from 535 to 2123 ms) were performed with heart rate and rhythm simulated at 60 and 120 beats per minute (bpm) and arrhythmia using an external triggering device. Ten human subjects and 17 large animals were scanned precontrast and 5, 10, and 15 min after contrast agent administration.

Results

Compared with the reference T1 mapping, AIR yielded lower normalized root‐mean‐square error than MOLLI (8% vs. 3%, respectively, at 60 bpm, 28% vs. 3%, respectively, at 120 bpm, and 22% vs. 3%, respectively, at arrhythmia). In vivo studies showed that T1 measurements made by MOLLI and AIR were strongly correlated (r = 0.99) but in poor agreement (mean difference = 161.8 ms, upper and lower 95% limits of agreements = 347.5 ms and −24.0 ms).

Conclusion

Our AIR pulse sequence may be clinically useful for assessment of diffuse myocardial fibrosis in patients. Magn Reson Med 70:1274–1282, 2013. © 2012 Wiley Periodicals, Inc.
Perfusion quantification by model‐free arterial spin labeling using nonlinear stochastic regularization deconvolution
Authors: Ahlgren André , Wirestam Ronnie , Petersen Esben Thade , Ståhlberg Freddy , Knutsson Linda
Published: December 2012

Purpose

Quantification of cerebral blood flow can be accomplished by model‐free arterial spin labeling using the quantitative STAR labeling of arterial regions (QUASAR) sequence. The required deconvolution is normally based on block‐circulant singular value decomposition (cSVD)/oscillation SVD (oSVD), an algorithm associated with nonphysiological residue functions and potential effects of arterial dispersion. The aim of this work was to amend this by implementing nonlinear stochastic regularization (NSR) deconvolution, previously used to retrieve realistic residue functions in dynamic susceptibility contrast MRI.

Methods

To characterize the residue function in model‐free arterial spin labeling, and possibly to improve absolute cerebral blood flow quantification, NSR was applied to deconvolution of QUASAR data. For comparison, SVD‐based deconvolution was also employed. Residue function characteristics and cerebral blood flow values from 10 volunteers were obtained. Simulations were performed to support the in vivo results.

Results

NSR was able to resolve realistic residue functions in contrast to the SVD‐based methods. Mean cerebral blood flow estimates in gray matter were 36.6 ± 2.6, 28.6 ± 3.3, 40.9 ± 3.6, and 42.9 ± 3.9 mL/100 g/min for cSVD, oSVD, NSR, and NSR with correction for arterial dispersion, respectively. In simulations, the NSR‐based perfusion estimates showed better accuracy than the SVD‐based approaches.

Conclusion

Perfusion quantification by model‐free arterial spin labeling is evidently dependent on the selected deconvolution method, and NSR is a feasible alternative to SVD‐based methods. Magn Reson Med 70:1470–1480, 2013. © 2012 Wiley Periodicals, Inc.
Cine‐ASL: A steady‐pulsed arterial spin labeling method for myocardial perfusion mapping in mice. Part II. Theoretical model and sensitivity optimization
Authors: Capron Thibaut , Troalen Thomas , Cozzone Patrick J. , Bernard Monique , Kober Frank
Published: December 2012

In small rodent myocardial perfusion studies, the most widely used method is based on Look‐Locker measurements of the magnetization recovery after FAIR preparation, which bears limitations regarding acquisition efficiency due to the pulsed arterial spin labeling nature of the sequence. To improve efficiency, this two‐article set proposes a new steady‐pulsed arterial spin labeling scheme using a cine readout incorporating one tagging pulse per heart cycle. In this part, we derive a theoretical description of the magnetization time evolution in such a scheme. The combination of steady‐pulsed labeling and cine readout drives tissue magnetization into a stationary regime that explicitly depends on perfusion. In comparison with dedicated experiments on the mouse heart, the model is discussed and validated for perfusion quantification. The model predicts that in this regime, signal is independent of irregular dynamics occurring during acquisition, such as heart rate variations or arterial input function. Optimization of the sequence offers the possibility to increase the signal to noise ratio by efficient signal averaging. The sensitivity of this new method is shown to be more than three times larger than previously used techniques. Magn Reson Med 70:1399–1408, 2013. © 2012 Wiley Periodicals, Inc.