bluuebunny/crossref_metadata_2025 huggingface dataset:
Bibliographic index coverage of open‐access journals in six subject areas
Authors: Walters William H. , Linvill Anne C.
Published: May 2011

We investigate the extent to which open‐access (OA) journals and articles in biology, computer science, economics, history, medicine, and psychology are indexed in each of 11 bibliographic databases. We also look for variations in index coverage by journal subject, journal size, publisher type, publisher size, date of first OA issue, region of publication, language of publication, publication fee, and citation impact factor. Two databases, Biological Abstracts and PubMed, provide very good coverage of the OA journal literature, indexing 60 to 63% of all OA articles in their disciplines. Five databases provide moderately good coverage (22–41%), and four provide relatively poor coverage (0–12%). OA articles in biology journals, English‐only journals, high‐impact journals, and journals that charge publication fees of $1,000 or more are especially likely to be indexed. Conversely, articles from OA publishers in Africa, Asia, or Central/South America are especially unlikely to be indexed. Four of the 11 databases index commercially published articles at a substantially higher rate than articles published by universities, scholarly societies, nonprofit publishers, or governments. Finally, three databases—EBSCO Academic Search Complete, ProQuest Research Library, and Wilson OmniFile—provide less comprehensive coverage of OA articles than of articles in comparable subscription journals.
Piezofluorochromic and Aggregation‐Induced‐Emission Compounds Containing Triphenylethylene and Tetraphenylethylene Moieties
Authors: Xu Bingjia , Chi Zhenguo , Zhang Jianyong , Zhang Xiqi , Li Haiyin , Li Xiaofang , Liu Siwei , Zhang Yi , Xu Jiarui
Published: May 2011

New fluorescent compounds containing triphenylethylene and tetraphenylethylene moieties were synthesized, and their piezofluorochromic and aggregation‐induced emission behaviors were investigated. The results show that all compounds exhibit aggregation‐induced emission characteristics and only the crystalline compound possesses piezofluorochromic properties. The color, emission spectra, and morphological structures of the one piezofluorochromic compound exhibit reversibility upon grinding and annealing (or fuming) treatments. The piezofluorochromic behaviors are caused by a change between different modes of solid state molecular packing under external pressure. The single crystal X‐ray diffraction analysis reveals that the twisted conformation of the aggregation‐induced emission compound leads to the formation of metastable crystal lattice with cavity which is readily destroyed under external pressure. A possible mechanism of piezofluorochromic phenomenon has been proposed.
Life cycle assessment of Brazilian sugarcane products: GHG emissions and energy use
Authors: Seabra Joaquim E. A. , Macedo Isaias C. , Chum Helena L. , Faroni Carlos E. , Sarto Celso A.
Published: May 2011

Sugarcane is currently the main renewable energy source in Brazil. Due to the importance of the cane industry and its contribution to a wide range of biobased energy and other products, LCA studies regarding cane‐derived products are needed to assess their environmental benefits. The main objective of this work was the assessment of life cycle energy use and greenhouse gas (GHG) emissions related to cane sugar and ethanol, considering bagasse and electricity surpluses as coproducts. We performed an overall balance for the Brazilian Center‐South Region, adopting different methods to evaluate sugar and ethanol production separately. The GREET 1.8c.0 model was used for the ‘well‐to‐wheels’ calculations but adapted to the comprehensive set of Brazilian parameters that best represent the Center‐South Region. For the reference case, fossil energy use and GHG emissions related to sugar production were evaluated as 721 kJ/kg and 234 g CO2eq/kg, respectively. For the ethanol life cycle, these values were 80 kJ/MJ and 21.3 g CO2eq/MJ. Special attention was paid to the variation of some parameters among producing units based on data collected by industry. The consequent uncertainties in ethanol life cycle emissions were assessed through a Monte Carlo analysis based on assigned distribution of probability curves for eleven selected parameters and informed by partial statistical data available from industry for distribution generation. Projections were also made for 2020 scenario parameters based on the best in current class technologies and technological improvements deemed commercially possible today. Published in 2011 by John Wiley & Sons, Ltd
Site‐Specific Labeling of Proteins by Using Biotin Protein Ligase Conjugated with Fluorophores
Authors: Sueda Shinji , Yoneda Sawako , Hayashi Hideki
Published: May 2011

Biotin protein ligase (BPL) mediates the covalent attachment of biotin to a specific lysine residue of biotin carboxyl carrier protein (BCCP). This biotinylation in Sulfolobus tokodaii is unique in that BPL forms a tight complex with the product, biotinylated BCCP, and this property was exploited for fluorescent labeling of a membrane protein. Thus, the truncated form of BCCP (BCCPΔ100, 69 residues) was fused to either the N or C terminus of the bradykinin B2 receptor (B2R). The resulting fusion proteins, BCCPΔ100–B2R and B2R–BCCPΔ100, respectively, were separately expressed in mammalian HEK293 cells, and labeled with BPL conjugated with a fluorophore: either fluorescein, DyLight549 or green fluorescent protein. The fusion proteins were biotinylated and bound to BPL, thereby giving rise to strong fluorescence along the periphery of the cell. Some were capable of binding bradykinin and an antagonist. When stimulated with the former, the receptor translocated to the cytosol; this suggests that the labeled receptor retains its integrity in terms of ligand‐binding and translocation.
Synthesis, Structural Characterization, and Pro‐apoptotic Activity of 1‐Indanone Thiosemicarbazone Platinum(II) and Palladium(II) Complexes: Potential as Antileukemic Agents
Authors: Gómez Natalia , Santos Diego , Vázquez Ramiro , Suescun Leopoldo , Mombrú Álvaro , Vermeulen Monica , Finkielsztein Liliana , Shayo Carina , Moglioni Albertina , Gambino Dinorah , Davio Carlos
Published: May 2011

In the search for alternative chemotherapeutic strategies against leukemia, various 1‐indanone thiosemicarbazones, as well as eight novel platinum(II) and palladium(II) complexes, with the formula [MCl2(HL)] and [M(HL)(L)]Cl, derived from two 1‐indanone thiosemicarbazones were synthesized and tested for antiproliferative activity against the human leukemia U937 cell line. The crystal structure of [Pt(HL1)(L1)]Cl.2MeOH, where L1=1‐indanone thiosemicarbazone, was solved by X‐ray diffraction. Free thiosemicarbazone ligands showed no antiproliferative effect, but the corresponding platinum(II) and palladium(II) complexes inhibited cell proliferation and induced apoptosis. Platinum(II) complexes also displayed selective apoptotic activity in U937 cells but not in peripheral blood monocytes or the human hepatocellular carcinoma HepG2 cell line used to screen for potential hepatotoxicity. Present findings show that, in U937 cells, 1‐indanone thiosemicarbazones coordinated to palladium(II) were more cytotoxic than those complexed with platinum(II), although the latter were found to be more selective for leukemic cells suggesting that they are promising compounds with potential therapeutic application against hematological malignancies.
Aromatase and Dual Aromatase‐Steroid Sulfatase Inhibitors from the Letrozole and Vorozole Templates
Authors: Wood Paul M. , Woo L. W. Lawrence , Thomas Mark P. , Mahon Mary F. , Purohit Atul , Potter Barry V. L.
Published: May 2011

Concurrent inhibition of aromatase and steroid sulfatase (STS) may provide a more effective treatment for hormone‐dependent breast cancer than monotherapy against individual enzymes, and several dual aromatase–sulfatase inhibitors (DASIs) have been reported. Three aromatase inhibitors with sub‐nanomolar potency, better than the benchmark agent letrozole, were designed. To further explore the DASI concept, a new series of letrozole‐derived sulfamates and a vorozole‐based sulfamate were designed and biologically evaluated in JEG‐3 cells to reveal structure–activity relationships. Amongst achiral and racemic compounds, 2‐bromo‐4‐(2‐(4‐cyanophenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)ethyl)phenyl sulfamate is the most potent DASI (aromatase: IC50=0.87 nM; STS: IC50=593 nM). The enantiomers of the phenolic precursor to this compound were separated by chiral HPLC and their absolute configuration determined by X‐ray crystallography. Following conversion to their corresponding sulfamates, the S‐(+)‐enantiomer was found to inhibit aromatase and sulfatase most potently (aromatase: IC50=0.52 nM; STS: IC50=280 nM). The docking of each enantiomer and other ligands into the aromatase and sulfatase active sites was also investigated.
The Kinetics of Ferrocene Volatilisation from an Ionic Liquid
Authors: Fu Chaopeng , Aldous Leigh , Dickinson Edmund J. F. , Manan Ninie S. A. , Compton Richard G.
Published: May 2011

The volatilisation of ferrocene (Fc), dissolved in the ionic liquid N‐butyl‐N‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr][NTf2], to the gas phase has been indirectly monitored by cyclic voltammetry and chronoamperometry. Simulation of the observed trends in concentration with time using a simple model allowed quantification of the process. Volatilisation of dissolved Fc under flowing wet and dry dinitrogen gas (N2) was found to be kinetically limited with a rate constant in the region of 2×10−7 cm s−1. The activation energy of diffusion for Fc was found to be 28.2±0.7 kJ mol−1, while the activation energy of volatilisation of Fc from [C4mpyrr][NTf2] to dry N2 was found to be 85±2 kJ mol−1.
Immobilization of Apoferritin‐Templated Seeds for Si Nanowire Growth
Authors: Zhang Zhang , Zhang Lianbing , Senz Stephan , Knez Mato
Published: May 2011

Small Au nanoparticles with a confined size are synthesized exclusively inside the protein cavity of apoferritin (Au‐apo). A modified immobilization process is used to decorate a large area of a Si substrate with monodisperse Au‐apo. After removing the protein, the immobilized Au nanoparticles act as catalysts for a subsequent sub‐10 nm diameter silicon nanowire (SiNW) growth by CVD. The immobilization of Au catalysts by linking the biotemplate to a Si substrate provides a possible route to control the location of the semiconductor NW in advance of the growth.
Parental disorders, childhood abuse, and binge eating in a large community sample
Authors: Ericsson Natalie Sachs‐ , Keel Pamela K. , Holland Lauren , Selby Edward A. , Verona Edelyn , Cougle Jesse R. , Palmer Emily
Published: May 2011

Objective:

Genetic and nonshared environmental factors are implicated in the etiology of binge eating behaviors (BEB), with genetic risk expressed as parental psychopathology. Traumatic experiences including child abuse predict onset of BEB. It is not clear if each separately contribute to BEB, or whether parental pathology leads to abuse which in turn influences BEB.

Method:

Data were obtained from the National Comorbidity Survey‐Replication (N = 2960). Through structural equation modeling, we estimated unique and combined effects of mother's and father's internalizing (INT) and externalizing (EXT) disorders, and child abuse on BEB.

Results:

Parental INT and EXT psychopathology contributed to child abuse and BEB. Abuse predicted BEB and partially mediated associations between parental psychopathology and BEB.

Discussion:

Results emphasize the value of models that incorporate nature and nurture to understand risk for psychopathology in offspring, with childhood abuse being one mediator of how parental psychopathology may reflect genetic risk and influence environmental risk. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012;)
Batf3 transcription factor‐dependent DC subsets in murine CMV infection: Differential impact on T‐cell priming and memory inflation
Authors: Torti Nicole , Walton Senta M. , Murphy Kenneth M. , Oxenius Annette
Published: May 2011

Priming of CD8+ T cells specific for viruses that interfere with the MHC class I presentation pathway is a challenge for the immune system and is believed to rely on cross‐presentation. Cytomegalovirus (CMV) infection induces vigorous CD8+ T‐cell responses despite its potent immune evasion strategies. Furthermore, CD8+ T cells specific for a subset of viral epitopes accumulate and are maintained at high levels exhibiting an activated phenotype – referred to as “inflationary T cells”. Taking advantage Batf3−/− mice in which the development of cross‐presenting CD8α+ and CD103+ DCs is severely compromised, we analyzed their role in the induction and inflation of murine (M)CMV‐specific CD8+ T‐cell responses. We found that priming of MCMV‐specific CD8+ T cells was severely impaired in the absence of cross‐presenting DCs. However, inflation of two immuno‐dominant MCMV‐specific CD8+ T‐cell populations was largely normal in the absence of cross‐presenting DCs, indicating that inflation during latency was mainly dependent on direct antigen presentation. These results highlight differential antigen presentation requirements during acute and latent MCMV infection.
Efficient generation of B lymphocytes by recognition of self‐antigens
Authors: Eschbach Cathrin , Bach Martina P. , Fidler Ingrid , Pelanda Roberta , Köhler Fabian , Rajewsky Klaus , Jumaa Hassan
Published: May 2011

Antibody diversity is generated by a random gene recombination process with the inherent risk of the production of autoreactive specificities. The current view suggests that B cells expressing such specificities are negatively selected at an early developmental stage. Using the knock‐in model system of the 3‐83 autoreactive B‐cell antigen receptor (BCR) in combination with precursor‐BCR (pre‐BCR) deficiency, we show here that the 3‐83 BCR mediates efficient generation of B cells in the presence, but not the absence, of a strongly recognized auto‐antigen. Experiments with mixed bone marrow chimeras showed that combining the 3‐83 BCR with the corresponding auto‐antigen resulted in efficient reconstitution of B‐cell development in immune‐deficient mice. These results suggest that B cells are positively selected by recognition of self‐antigens during developmental stages that precede receptor editing. Moreover, the data indicate that the pre‐BCR functions as a specialized autoreactive BCR to initiate positive selection at a stage where the cells express immunoglobulin heavy but not light chains.
Electrochemical Behavior of a Glassy Carbon Electrode Chemically Modified with Nickel Pentacyanonitrosylferrate in Presence of Sulfur Compounds
Authors: Paim Leonardo L. , Hammer Peter , Stradiotto Nelson R.
Published: May 2011

The glassy carbon electrode was modified with a nickel pentacyanonitrosylferrate film by electrodeposition of Ni and subsequent derivatization with NaPCNF. The film was characterized by XPS and electrochemical methods. Cyclic voltammetry of the NiPCNF onto the GC shows a redox couple (FeIII/FeII) with E°′ of 538 mV (Ipa/Ipc around 1) and ΔEp of 93 mV in 0.5 mol L−1 KNO3, with a diffusion‐controlled process. There was a decrease of anodic peak currents of the film in the presence of sulfide and 2‐propanethiol due to a precipitation reaction on the film surface by nucleophilic attack.
Tracing the Tracks of Cosmic Rain
Authors: Trieloff Mario
Published: May 2011

A collision of two large asteroids between Mars and Jupiter occurred 470 million years ago. Even today, every third meteorite that strikes Earth can be traced back to this prehistoric crash. From fallen fragments, geoscientists gain new insights into the history of the solar system
“I still have a suitcase in Dresden …”
Authors: Unterstell Rembert
Published: May 2011

An opportunity to make new contacts in the international research community – following the 60th Nobel Laureate Meeting at Lake Constance, twenty young Indian researchers embarked on a tour of Germany',s research landscape, visiting universities and institutes around the country. We spoke with two of the participants about their experiences

http://www.dfg.de/indien
Fukushima Daiichi: Implications for carbon-free energy, nuclear nonproliferation, and community resilience
Authors: Hall Howard L.
Published: May 2011

Implications of the nuclear power plant accidents at Fukushima Daiichi are explored in this commentary. In addition to questions of nuclear reactor regulatory standards, broader implications on noncarbon-emitting energy production, nuclear nonproliferation objectives, and community resilience and emergency response against catastrophic events are explored. Integr Environ Assess Manag 2011;7:406–408. © 2011 SETAC
Lessons in risk- versus resilience-based design and management
Authors: Park Jeryang , Seager Thomas P , Rao P Suresh C
Published: May 2011

The implications of recent catastrophic disasters, including the Fukushima Daiichi nuclear power plant accident, reach well beyond the immediate, direct environmental and human health risks. In a complex coupled system, disruptions from natural disasters and man-made accidents can quickly propagate through a complex chain of networks to cause unpredictable failures in other economic or social networks and other parts of the world. Recent disasters have revealed the inadequacy of a classical risk management approach. This study calls for a new resilience-based design and management paradigm that draws upon the ecological analogues of diversity and adaptation in response to low-probability and high-consequence disruptions. Integr Environ Assess Manag 2011;7:396–399. © 2011 SETAC
Environmental risk management for radiological accidents: Integrating risk assessment and decision analysis for remediation at different spatial scales
Authors: Yatsalo Boris , Sullivan Terrence , Didenko Vladimir , Linkov Igor
Published: May 2011

The consequences of the Tohuku earthquake and subsequent tsunami in March 2011 caused a loss of power at the Fukushima Daiichi nuclear power plant, in Japan, and led to the release of radioactive materials into the environment. Although the full extent of the contamination is not currently known, the highly complex nature of the environmental contamination (radionuclides in water, soil, and agricultural produce) typical of nuclear accidents requires a detailed geospatial analysis of information with the ability to extrapolate across different scales with applications to risk assessment models and decision making support. This article briefly summarizes the approach used to inform risk-based land management and remediation decision making after the Chernobyl, Soviet Ukraine, accident in 1986. Integr Environ Assess Manag 2011;7:393–395. © 2011 SETAC
A Bayesian network model for integrative river rehabilitation planning and management
Authors: Borsuk Mark E , Schweizer Steffen , Reichert Peter
Published: May 2011

As rehabilitation of previously channelized rivers becomes more common worldwide, flexible integrative modeling tools are needed to help predict the morphological, hydraulic, economic, and ecological consequences of the rehabilitation activities. Such predictions can provide the basis for planning and long-term management efforts that attempt to balance the diverse interests of river system stakeholders. We have previously reported on a variety of modeling methods and decision support concepts that can assist with various aspects of the river rehabilitation process. Here, we bring all of these tools together into a probability network model that links management actions, through morphological and hydraulic changes, to the ultimate ecological and economic consequences. Although our model uses a causal graph representation common to Bayesian networks, we do not limit ourselves to discrete-valued nodes or conditional Gaussian distributions as required by most Bayesian network implementations. This precludes us from carrying out easy probabilistic inference but gives us the advantages of functional and distributional flexibility and enhanced predictive accuracy, which we believe to be more important in most environmental management applications. We exemplify model application to a large, recently completed rehabilitation project in Switzerland. Integr Environ Assess Manag 2012; 8: 462–472. © SETAC
Soil vulnerability for cesium transfer
Authors: Vandenhove Hildegarde , Sweeck Lieve
Published: May 2011

The recent events at the Fukushima Daiichi nuclear power plant in Japan have raised questions about the accumulation of radionuclides in soils and the possible impacts on agriculture surrounding nuclear power plants. This article summarizes the knowledge gained after the nuclear power plant accident in Chernobyl, Ukraine, on how soil parameters influence soil vulnerability for radiocesium bioavailability, discusses some potential agrochemical countermeasures, and presents some predictions of radiocesium crop concentrations for areas affected by the Fukushima accident. Integr Environ Assess Manag 2011;7:374–378. © 2011 SETAC
Effects of ionizing radiation on wildlife: What knowledge have we gained between the Chernobyl and Fukushima accidents?
Authors: Beresford Nicholas A , Copplestone David
Published: May 2011

The recent events at the Fukushima Daiichi nuclear power plant in Japan have raised questions over the effects of radiation in the environment. This article considers what we have learned about the radiological consequences for the environment from the Chernobyl accident, Ukraine, in April 1986. The literature offers mixed opinions of the long-term impacts on wildlife close to the Chernobyl plant, with some articles reporting significant effects at very low dose rates (below natural background dose rate levels in, for example, the United Kingdom). The lack of agreement highlights the need for further research to establish whether current radiological protection criteria for wildlife are adequate (and to determine if there are any implications for human radiological protection). Integr Environ Assess Manag 2011;7:371–373. © 2011 SETAC
Impaired tumor rejection by memory CD8 T cells in mice with NKG2D dysfunction
Authors: André Maya Caroline , Sigurdardottir Dagmar , Kuttruff Sabrina , Pömmerl Beate , Handgretinger Rupert , Rammensee Hans‐Georg , Steinle Alexander
Published: May 2011

Cytotoxic T cells are important effectors for robust antitumor immune responses. However, tumor‐infiltrating CD8 T cells are often functionally impaired. Insufficient antitumor activity of CD8 T cells can be due to a lack of costimulatory signals. NKG2D is such a costimulatory receptor on CD8 T cells that facilitates immunorecognition of stressed and malignant cells, promotes tumor rejection by NK and CD8 T cells and contributes to immunosurveillance of spontaneous malignancies. Previous reports suggested an involvement of NKG2D in establishing CD8 T cell‐mediated antitumor memory. However, the significance of NKG2D for the generation and effector phase of memory CD8 T cell responses is largely unknown. To address these issues, we made use of a transgenic mouse model (H2‐Kb‐MICA mice) where the human NKG2D ligand MICA is ubiquitously and constitutively expressed resulting in a severe dysfunction of NKG2D. Both, ovalbumin (OVA)‐specific (H2‐Kb/OVA257–264) memory CD8 T cells arisen from the endogenous T cell pool and adoptively transferred OVA‐specific OT‐I memory cells were unable to control growth of an OVA‐expressing lymphoma in H2‐Kb‐MICA mice. While expansion of memory T cells in these mice on antigen challenge was not different from controls, CD8 memory T cells of H2‐Kb‐MICA mice did not effectively eliminate tumor cells in vivo. Altogether, our data suggest that NKG2D has no major role in the generation and expansion of memory CD8 T cells, but rather substantially enhances the cytolytic effector responses of reactivated memory T cells and thereby contributes to an efficacious tumor rejection.
Switch from cytology‐based to human papillomavirus test‐based cervical screening: Implications for colposcopy
Authors: Porras Carolina , Wentzensen Nicolas , Rodríguez Ana C. , Morales Jorge , Burk Robert D. , Alfaro Mario , Hutchinson Martha , Herrero Rolando , Hildesheim Allan , Sherman Mark E. , Wacholder Sholom , Solomon Diane , Schiffman Mark
Published: May 2011

Human papillomavirus (HPV) testing is more sensitive than cytology; some cervical cancer prevention programs will switch from cytology to carcinogenic HPV test‐based screening. The objective of our study is to evaluate the clinical implications of a switch to HPV test‐based screening on performance and workload of colposcopy. Women in the population‐based, 7‐year Guanacaste cohort study were screened at enrollment using cytology. We also took another specimen for HPV DNA testing and collected magnified cervical photographic images (cervigrams). A final case diagnosis (≥cervical intraepithelial neoplasia [CIN] grade 3, CIN2, <CIN2) was assigned at exit. Using the cervigram as a surrogate of colposcopy impression, we evaluated the impact of changing screening method from cytology to carcinogenic HPV testing on the distribution of enrollment colposcopic impression and on the predictive values of positive and negative colposcopic impressions for the cumulative 7‐year detection of ≥CIN2 and ≥CIN3. A program based on immediate colposcopic referral after positive HPV would immediately identify as high risk more of the cumulative ≥CIN2 cases than conventional cytology, because of an increased number of referrals. However, the proportion of women that would have visible lesions at referral to colposcopy and the sensitivity versus specificity trade‐off of the colposcopic impressions would be similar to programs using cytology (≥ atypical squamous cells of unknown significance [ASCUS]) for referral. The major concern with switching from cytology to more sensitive HPV screening is management of the many HPV‐positive women, including those with still nonvisible ≥CIN2 lesions. Our data support the need for a nonvisual diagnostic method to guide management and treatment of HPV‐positive women.
Effects of acetyl salycilic acid and ibuprofen in chronic liver damage induced by CCl4
Authors: Chávez Enrique , Castro‐Sánchez Luis , Shibayama Mineko , Tsutsumi Victor , Pérez Salazar Eduardo , Moreno Mario G. , Muriel Pablo
Published: May 2011

Non‐steroidal anti‐inflammatory drugs (NSAIDs) are drugs used primarily to treat inflammation, pain and fever. Their main mechanism of action is cyclooxygenase (COX) inhibition, and this enzyme has been linked to hepatotoxicity. The association of COX and liver injury has been, in part, due to the presence of COX‐2 isoform in damaged liver and the possible induction of this enzyme by profibrotic molecules like Transforming Growth Factor‐β (TGF‐β). The aim of this work was to evaluate the effects of two of the most used NSAIDs, acetyl salicylic acid (ASA) and ibuprofen (IBP), on experimental liver fibrosis. We formed experimental groups of rats including vehicle and drug controls, damage induced by chronic CCl4 (0.4 g kg−1, i.p., three times per week, for 8 weeks) administration, and CCl4 plus ASA (100 mg kg−1, p.o., daily) or IBP (30 mg kg−1, p.o., daily). Both drugs showed important antifibrotic properties. They inhibited COX‐2 activity, prevented oxidative stress measured as lipid peroxidation and glutathione content, and ASA inhibited partially and IBP totally increased TGF‐β expression and collagen content. ASA and IBP prevented translocation of NFκB to the nucleus and, interestingly, ASA induced MMP‐2 and MMP‐13 whereas IBP induced MMP‐2, MMP‐9 and MMP‐13. As a whole, these effects explain the beneficial effects of ASA and IBP on experimental liver fibrosis. Copyright © 2011 John Wiley & Sons, Ltd.
Portal hypertension correlates with splenic stiffness as measured with MR elastography
Authors: Nedredal Geir I. , Yin Meng , McKenzie Travis , Lillegard Joseph , Luebke‐Wheeler Jennifer , Talwalkar Jayant , Ehman Richard , Nyberg Scott L.
Published: May 2011

Purpose:

To investigate the correlation between MR elastography (MRE) assessed spleen stiffness and direct portal vein pressure gradient (D‐HVPG) measurements in a large animal model of portal hypertension.

Materials and Methods:

Cholestatic liver disease was established in adult canines by common bile duct ligation. A spin echo based echo planar imaging (EPI) MRE sequence was used to acquire three‐dimensional/three axis (3D/3‐axis) abdominal MRE data at baseline, 4 weeks, and 8 weeks. Liver biopsies, blood samples, and D‐HVPG measurements were obtained simultaneously.

Results:

Animals developed portal hypertension (D‐HVPG: 11.0 ± 5.1 mmHg) with only F1 fibrosis after 4 weeks. F3 fibrosis was confirmed after 8 weeks despite no further rise in portal hypertension (D‐HVPG: 11.3 ± 3.2 mmHg). Mean stiffnesses of the spleen increased over two‐fold from baseline (1.72 ± 0.33 kPa) to 4 weeks (3.54 ± 0.31 kPa), and stabilized at 8 weeks (3.38 ± 0.06 kPa) in a pattern consistent with changes in portal pressure. A positive correlation was observed between spleen stiffness and D‐HVPG (r2 = 0.86; P < 0.01).

Conclusion:

These findings indicate a temporal relationship between portal hypertension and the development of liver fibrosis in a large animal model of cholestatic liver disease. The observed direct correlation between spleen stiffness and D‐HVPG suggest a noninvasive MRE approach to diagnose and screen for portal hypertension. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Hepatic enhancement during the hepatobiliary phase after gadoxetate disodium administration in patients with chronic liver disease: The role of laboratory factors
Authors: Chernyak Victoria , Kim Jane , Rozenblit Alla M. , Mazzoriol Fernanda , Ricci Zina
Published: May 2011

Purpose:

To identify factors influencing hepatobiliary phase (HBP) hepatic enhancement on gadoxetate disodium‐enhanced MRI in patients with chronic liver disease (CLD).

Materials and Methods:

We retrospectively reviewed abdominal gadoxetate disodium‐enhanced MRIs and medical records of patients with (n = 97) and without (n = 48) CLD. CLD subgroups were formed based on normal/abnormal components of liver function tests (LFTs). Hepatic enhancement coefficients (HEKs) were calculated on MRI, and compared with LFTs and Model for End‐stage Liver Disease (MELD) scores.

Results:

The mean HEK was significantly lower (P < 0.0008) in the CLD than control group. The mean HEK was similar to controls in the subgroup with all normal LFTs (P = 0.09) and subgroup with normal direct bilirubin (DB) (p = 0.09), while it was significantly reduced (P < 0.0001) in the subgroup with elevated DB. For all other LFT components, regardless of normal or abnormal values, there was a significant reduction in the mean HEKs versus controls (all P values <0.01). There was a highly negative correlation between the mean HEKs in CLD subgroups and number of abnormal LFTs (r = −0.93) and MELD scores (r = −0.89).

Conclusion:

HBP hepatic enhancement in CLD patients is similar to those with no CLD as long as direct bilirubin remains normal. Higher MELD scores and higher number of abnormal LFT components are associated with reduced hepatic enhancement. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Disposable pipette extraction for gas chromatographic determination of codeine, morphine, and 6‐monoacetylmorphine in vitreous humor
Authors: Kovatsi Leda , Rentifis Konstantinos , Giannakis Dimitrios , Njau Samuel , Samanidou Victoria
Published: May 2011

The availability of a sensitive and rapid analytical method for the determination of opiates, and other substances of forensic interest, in a variety of biological specimens is of utmost importance to forensic laboratories. Solid‐phase extraction is very popular in the pre‐treatment of forensic samples. Nevertheless, a new approach, disposable pipette extraction (DPX), is gaining increasing interest in sample preparation. DPX has already been applied to the analysis of drugs of abuse in common biological matrices, such as urine and blood, but has not yet been evaluated on alternative biological samples, such as vitreous humor. The objective of this study was to evaluate the applicability of DPX on the analysis of opiates in vitreous humor. The currently developed method is fast, reliable, and easy to perform. The sensitivity, precision, and accuracy are satisfactory. Recoveries obtained are within the range of 72–91%, whereas the sample volume of vitreous humor required is only 100 μL.
Quantitative magnetization transfer imaging in human brain at 3 T via selective inversion recovery
Authors: Dortch Richard D. , Li Ke , Gochberg Daniel F. , Welch E. Brian , Dula Adrienne N. , Tamhane Ashish A. , Gore John C. , Smith Seth A.
Published: May 2011

Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons—including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools kmf. This study describes the first implementation of the selective inversion recovery quantitative magnetization transfer method on a clinical 3.0‐T scanner in human brain in vivo. Selective inversion recovery data were acquired at 16 different inversion times in nine healthy subjects and two patients with relapsing remitting multiple sclerosis. Data were collected using a fast spin‐echo readout and reduced repetition time, resulting in an acquisition time of 4 min for a single slice. In healthy subjects, excellent intersubject and intrasubject reproducibilities (assessed via repeated measures) were demonstrated. Furthermore, PSR values in white (mean ± SD = 11.4 ± 1.2%) and gray matter (7.5 ± 0.7%) were consistent with previously reported values, while kmf values were approximately 2‐fold slower in both white (11 ± 2 s–1) and gray matter (15 ± 6 s–1). In relapsing remitting multiple sclerosis patients, quantitative magnetization transfer indices were sensitive to pathological changes in lesions and in normal appearing white matter. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Imaging the extracellular pH of tumors by MRI after injection of a single cocktail of T1 and T2 contrast agents
Authors: Martinez Gary V. , Zhang Xiaomeng , García‐Martín María L. , Morse David L. , Woods Mark , Sherry A. Dean , Gillies Robert J.
Published: May 2011

The extracellular pH (pHe) of solid tumors is acidic, and there is evidence that an acidic pHe is related to invasiveness. Herein, we describe an MRI single‐infusion method to measure pHe in gliomas using a cocktail of contrast agents (CAs). The cocktail contained gadolinium–1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraaminophosphonate (GdDOTA‐4AmP) and dysprosium–1,4,7,10‐tetraazacyclododecane‐N,N′,N′′,N′′′‐tetrakis(methylenephosphonic acid) (DyDOTP), whose effects on relaxation are sensitive and insensitive to pH, respectively. The Gd‐CA dominated the spin–lattice relaxivity ΔR1, whereas the Dy‐CA dominated the spin–spin relaxivity ΔR2*. The ΔR2* effects were used to determine the pixel‐wise concentration of [Dy] which, in turn, was used to calculate a value for [Gd] concentration. This value was used to convert ΔR1 values to the molar relaxivity Δr1 and, hence, pHe maps. The development of the method involved in vivo calibration and measurements in a rat brain glioma model. The calibration phase consisted of determining a quantitative relationship between ΔR1 and ΔR2* induced by the two pH‐independent CAs, gadolinium–diethylenetriaminepentaacetic acid (GdDTPA) and DyDOTP, using echo planar spectroscopic imaging (EPSI) and T1‐weighted images. The intensities and linewidths of the water peaks in EPSI images were affected by CA and were used to follow the pharmacokinetics. These data showed a linear relationship between inner‐ and outer‐sphere relaxation rate constants that were used for CA concentration determination. Nonlinearity in the slope of the relationship was observed and ascribed to variations in vascular permeability. In the pHe measurement phase, GdDOTA‐4AmP was infused instead of GdDTPA, and relaxivities were obtained through the combination of interleaved T1‐weighted images (R1) and EPSI for ΔR2*. The resulting r1 values yielded pHe maps with high spatial resolution. Copyright © 2011 John Wiley & Sons, Ltd.
Higher order eigensensitivities‐based numerical method for the harmonic analysis of viscoelastically damped structures
Authors: Martinez‐Agirre M. , Elejabarrieta M. J.
Published: May 2011

This paper presents an efficient numerical method for the harmonic analysis of viscoelastically damped structural systems characterized by a frequency‐dependent structural damping matrix, making use of the complex mode superposition method. Departing from the undamped eigensolution, the proposed numerical method updates the complex and frequency‐dependent eigenpair avoiding the solution of a complex eigenproblem for each computational frequency. The complex eigenvalues and eigenvectors are updated within the desired tolerance by an adaptive step‐size control scheme using the first‐ and higher order eigenderivatives. The influence on the computation time of the considered number of eigenderivatives and the tolerance is discussed, and the efficiency of the proposed numerical method for the harmonic analysis of viscoelastically damped large‐ordered structural systems is proved. Finally, a practical application is presented where the harmonic response of a constrained layer damping cantilever beam subjected to a base motion is analyzed. The complex and frequency‐dependent eigenvalues and eigenvectors are computed, the modal contributions to the total response are determined, and the total response is approximated by the complex mode superposition method. Finally, the approximated response is validated with the exact one computed by the direct frequency method and with that experimentally measured. Copyright © 2011 John Wiley & Sons, Ltd.
Rapid weight loss and pain in the foot
Authors: Kong M‐F , Nisal K , Gregory R
Published: May 2011

A 52‐year‐old man was referred with a 15kg weight loss over eight weeks associated with loss of appetite, nausea and early satiety. The day before admission he developed numbness and pins and needles in his left foot. He had hypertension and diabetes which was diagnosed three years previously. His control was very good with latest HbA1c of 6.6% (49mmol/mol) on metformin only. He had no evidence of microvascular complications. He had extensive investigations which included CT head, thorax, abdomen and pelvis, tumour markers, prostatic specific antigen, autoantibody screen and protein electrophoresis, which were all normal. Nerve conduction studies and electromyography confirmed right ulnar neuropathy and showed non‐specific neuropathy in the lower limbs. A diagnosis of diabetic neuropathic cachexia was made.

It is important for this condition to be recognised and considered in patients with diabetes mellitus in order to avoid unnecessary and lengthy investigations. Copyright © 2011 John Wiley & Sons.
Polymer hybrid films based on silica and a poly(ether imide) containing phthalide groups
Authors: Hamciuc Elena , Hamciuc Corneliu , Bacosca Irina , Okrasa Lidia
Published: May 2011

A study of thermal and electrical behavior of some silica‐containing poly(ether imide) films is presented. The hybrid films were prepared using a poly(amic acid) having phthalide groups and tetraethoxysilane via sol–gel technique and thermal cyclodehydration. Effects of inorganic particle content on polymer composite properties were investigated. Thermal and electrical characteristics of hybrid films were evaluated with respect to their structure. The films were flexible and showed good thermal properties having the initial decomposition temperature above 400°C and glass transition temperature in the range of 240–248°C. The dielectric spectroscopy revealed subglass transitions δ, γ, and β. At higher temperature, an α‐relaxation corresponding to the glass transition and the normal mode appeared. The dielectric constant values were in the range of 3.21–3.64 at 20°C and 10 kHz. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Removal of methylene blue dyes from wastewater using cellulose‐based superadsorbent hydrogels
Authors: Zhou Yiming , Fu Shiyu , Liu Hao , Yang Shaoping , Zhan Huaiyu
Published: May 2011

Superadsorbent cellulose‐graft‐acrylic acid (C‐g‐AA) hydrogels were successfully prepared via free radical polymerization in phosphoric acid solution. Phosphoric acid solution provides a homogeneous reaction system. The C‐g‐AA hydrogels have a porous network inner structure with cellulose as the backbone. The introduced carboxyl groups enable the C‐g‐AA hydrogels with good swelling property (swelling ratio 7327%) and excellent MB adsorption capacity (equilibrium adsorption amount 2197 mg g−1). The dynamic swelling behaviors of the hydrogels were tested, water intake of hydrogels followed a non‐Fickian type diffusion. The effects of mole ratio of AA to cellulose, the pH of adsorption medium and the initial MB concentration on dye adsorption capacity of hydrogels were investigated. The adsorption isotherm and kinetics fit the Langmuir model and the Pseudo‐second‐order model well, respectively. Desorption was carried out in weak acid solution and 70% MB could be removed, suggesting the C‐g‐AA hydrogels had the potential for reuse. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
On the differences in micro‐deformation mechanism between isotactic polypropylene and β‐nucleated isotactic polypropylene as revealed by the confocal laser scanning microscopy
Authors: Jancar J. , Kalfus J. , Balkova R.
Published: May 2011

To understand the toughness enhancement of β‐nucleated isotactic polypropylene (iPP) in comparison with iPP, the differences in the micro‐deformation mechanisms between the neat iPP and β‐nucleated iPP were visualized using the confocal laser scanning microscopy (CLSM). Structure of the α‐ and β‐spherulites situated close to the tip of the sharp starter crack has been investigated during tensile deformation in the viewing field of the CLSM. In the α‐spherulite of the neat iPP, highly localized inter‐ and intra‐spherulitic micro‐shear bands have been observed. In the β‐nucleated iPP, relatively uniform distribution of diffuse shear bands has been observed in the β‐phase, while the α‐phase remained relatively undeformed exhibiting only narrow intra‐spherulitic shear bands in the direction perpendicular to the loading direction. Delocalization of plastic deformation into diffuse shear bands in β‐nucleated iPP can explain its enhanced crack resistance compared with the neat iPP exhibiting highly localized shear banding. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Effect of extensional properties of polymer solutions on the droplet formation via ultrasonic atomization
Authors: Kim Yubin , Kim Hyungsu
Published: May 2011

Ultrasonic atomization was conducted using 2.4 MHz ultrasound generator to produce polymeric particles from the solutions of water‐soluble polymers like poly (ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), and poly(vinyl pyrrolidone) (PVP). In the series of solutions containing these polymers of various molecular weights, the shear viscosity and surface tension were varied; such differences, however, could not account for the observed trends in the atomization behavior. It was found that the availability of droplet formation and size of the droplets depend strongly on the extensional characteristics of polymer solutions along with the apparent extensional viscosities and the longest relaxation times. The extensional properties of polymer solutions were effectively measured by capillary breakup extensional rheometry (CaBER) and provided a rational basis to understand the essential role of fluid viscoelasticity in ultrasonic atomization. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Synthesis and characterization of thiazolothiazole‐based polymers and their applications in polymer solar cells
Authors: Lee Sang Kyu , Kang In‐Nam , Lee Jong‐Cheol , Shin Won Suk , So Won‐Wook , Moon Sang‐Jin
Published: May 2011

A novel series of thiazolothiazole (Tz)‐based copolymers, poly[9,9‐didecylfluorene‐2,7‐diyl‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P1), poly[9,9‐dioctyldibenzosilole‐2,7‐diyl‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P2), and poly[4,4′‐bis(2‐ethylhexyl)‐dithieno[3,2‐b:2′,3′‐d]silole‐alt‐2,5‐bis‐(3‐hexylthiophene‐2‐yl)thiazolo[5,4‐d]thiazole] (P3), were synthesized for the use as donor materials in polymer solar cells (PSCs). The field‐effect carrier mobilities and the optical, electrochemical, and photovoltaic properties of the copolymers were investigated. The results suggest that the donor units in the copolymers significantly influenced the band gap, electronic energy levels, carrier mobilities, and photovoltaic properties of the copolymers. The band gaps of the copolymers were in the range of 1.80–2.14 eV. Under optimized conditions, the Tz‐based polymers showed power conversion efficiencies (PCEs) for the PSCs in the range of 2.23–2.75% under AM 1.5 illumination (100 mW/cm2). Among the three copolymers, P1, which contained a fluorene donor unit, showed a PCE of 2.75% with a short‐circuit current of 8.12 mA/cm2, open circuit voltage of 0.86 V, and a fill factor (FF) of 0.39, under AM 1.5 illumination (100 mW/cm2). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Facile fabrication and self‐assembly of polystyrene–silica asymmetric colloid spheres
Authors: Yin Yuyong , Zhou Shuxue , You Bo , Wu Limin
Published: May 2011

This study presents a very simple method to fabricate organic–inorganic asymmetric colloid spheres. In this approach, when silica particles are used as the Pickering emulsifier to stabilize the monomer droplets (styrene) in water via acid–base interaction between silica particles and auxiliary monomer (1‐vinylimidazole), the exposed surfaces of silica particles are very easy to be locally modified with 3‐(trimethoxysilyl)propyl methacrylate. When water‐based initiator is added, polystyrene–silica asymmetric colloid spheres are highly yielded. The sizes of silica and polymer particles can be tunable. These organic–inorganic anisotropic colloid spheres can self‐assemble into an interesting thickness‐dependent film. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and micellization of thermoresponsive galactose‐based diblock copolymers
Authors: Wang Ying , Li Xin , Hong Chunyan , Pan Caiyuan
Published: May 2011

Thermoresponsive double hydrophilic diblock copolymers poly(2‐(2′‐methoxyethoxy)ethyl methacrylate‐co‐oligo(ethylene glycol) methacrylate)‐b‐poly(6‐O‐methacryloyl‐D‐galactopyranose) (P(MEO2MA‐co‐OEGMA)‐b‐PMAGP) with various compositions and molecular weights were obtained by deprotection of amphiphilic diblock copolymers P(MEO2MA‐co‐OEGMA)‐b‐poly(6‐O‐methacryloyl‐1,2:3,4‐di‐O‐isopropylidene‐D‐galactopyranose) (P(MEO2MA‐co‐OEGMA)‐b‐PMAlpGP), which were prepared via reversible addition‐fragmentation chain transfer (RAFT) polymerization using P(MEO2MA‐co‐OEGMA) as macro‐RAFT agent. Dynamic light scattering and UV–vis studies showed that the micelles self‐assembled from P(MEO2MA‐co‐OEGMA)‐b‐PMAlpGP were thermoresponsive. A hydrophobic dye Nile Red could be encapsulated by block copolymers P(MEO2MA‐co‐OEGMA)‐b‐PMAGP upon micellization and released upon dissociation of the formed micelles under different temperatures. The galactose functional groups in the PMAGP block have specific interaction with HepG2 cells, and P(MEO2MA‐co‐OEGMA)‐b‐PMAGP has potential applications in hepatoma‐targeting drug delivery and biodetection. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011