bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproducibility of measurement of apparent diffusion coefficients of malignant hepatic tumors: Effect of DWI techniques and calculation methods
Authors: Kim So Yeon , Soo Lee Seung , Bumwoo Park  , Kim Namkug , Kim Jeong Kon , Park Seong Ho , Byun Jae Ho , Song Ki Jun , Koo Ja‐heung , Kyung Choi Eun , Lee Moon‐Gyu
Published: July 2012

Purpose:

To evaluate the effect of diffusion‐weighted imaging (DWI) methods, apparent diffusion coefficient (ADC) calculation methods, and selection of b‐values on the ADCs and the measurement reproducibility of malignant hepatic tumors.

Materials and Methods:

Nineteen patients with pathologically confirmed malignant hepatic tumors underwent breath‐hold DWI (b‐values = 0, 50, 500 s/mm2) and respiratory‐triggered DWI (0, 50, 300, 500, 1000 s/mm2) twice on a 1.5 T magnetic resonance imaging (MRI) scanner. ADCs were calculated using a two b‐value and/or a multiple b‐value method. The reproducibility of the ADC measurements was evaluated from the intraclass correlation coefficients (ICCs) and the 95% Bland–Altman limit‐of‐agreement (LOA).

Results:

The ADCs were different according to the DWI methods (P = 0.040–0.282), ADC calculation methods (P = 0.003–0.825), and the choice of b‐values (P < 0.001). The ADC tended to be more reproducible with use of breath‐hold DWI (ICC: 0.898–0.933; LOA, 18.8%–24.0%) than respiratory‐triggered DWI (ICC: 0.684–0.928; LOA, 15.0%–31.9%) (P = 0.008–0.122). For respiratory‐triggered DWI, the multiple b‐value method using five b‐values had better reproducibility than the two b‐value method for measurement of ADC (P = 0.009–0.221).

Conclusion:

The DWI method, ADC calculation method, and selection of b‐values potentially influence the ADCs and the reproducibility of malignant hepatic tumors. ADCs calculated from breath‐hold DWI are more reproducible than from respiratory‐triggered DWI. A multiple b‐value method may improve the reproducibility of respiratory‐triggered DWI. J. Magn. Reson. Imaging 2012;36:1131–1138. © 2012 Wiley Periodicals, Inc.
Formation of soy protein isolate–dextran conjugates by moderate Maillard reaction in macromolecular crowding conditions
Authors: Zhuo Xiu‐Ying , Qi Jun‐Ru , Yin Shou‐Wei , Yang Xiao‐Quan , Zhu Jian‐Hua , Huang Li‐Xin
Published: July 2012

BACKGROUND: Several methods have been reported for the conjugation of proteins with polysaccharides. Protein–polysaccharide conjugates can be formed by traditional dry heating, but this process is not attractive from an industrial viewpoint, and no commercial conjugates have been manufactured in this way. In the present study, in order to develop a more practical reaction method, macromolecular crowding was used to attach polysaccharides to proteins.

RESULTS: Soy protein isolate–dextran conjugates (SDCs) were prepared via the initial stage of the Maillard reaction in macromolecular crowding conditions. The impact of various processing conditions on the formation of SDCs was investigated. The optimal conditions chosen from the experiments were a soy protein isolate/dextran ratio of 1:1 (w/w), a pH of 6.5, a reaction temperature of 60 °C and a reaction time of 30 h. Circular dichroism spectroscopy showed that the secondary and tertiary structures of the conjugates were changed significantly. Structural flexibility increased, allowing better display of their functional characteristics. The conjugates had a composition with various sizes, especially macromolecules, according to gel permeation chromatography. Thermal analysis showed that the thermal stability of the conjugates was improved.

CONCLUSION: The production of SDCs under macromolecular crowding conditions appears to be an effective and promising technique, representing an advance over classic protein glycosylation methods. Copyright © 2012 Society of Chemical Industry
Range‐wide analysis of eastern massasauga survivorship
Authors: Jones Peter C. , King Richard B. , Bailey Robyn L. , Bieser Nickolas D. , Bissell Kristin , Campa Henry , Crabill Trisha , Cross Matthew D. , Degregorio Brett A. , Dreslik Michael J. , Durbian Francis E. , Harvey Daniel S. , Hecht Scott E. , Jellen Benjamin C. , Johnson Glenn , Kingsbury Bruce A. , Kowalski Matthew J. , Lee James , Manning Jennifer V. , Moore Jennifer A. , Oakes Julie , Phillips Christopher A. , Prior Kent A. , Refsnider Jeanine M. , Rouse Jeremy D. , Sage Joseph R. , Seigel Richard A. , Shepard Donald B. , Smith Chad S. , Vandewalle Terry J. , Weatherhead Patrick J. , Yagi Anne
Published: July 2012

Decisions affecting wildlife management and conservation policy of imperiled species are often aided by population models. Reliable population models require accurate estimates of vital rates and an understanding of how vital rates vary geographically. The eastern massasauga (Sistrurus catenatus catenatus) is a rattlesnake species found in the Great Lakes region of North America. Populations of the eastern massasauga are fragmented and only a few areas harbor multiple, sizable populations. Eastern massasauga research has typically focused on single populations or local metapopulations but results suggest that demographic parameters vary geographically. We used 21 radiotelemetry datasets comprising 499 telemetered snakes from 16 distinct locations throughout the range of the eastern massasauga to characterize geographic patterns of adult survival using the known‐fate model in Program MARK. Annual adult survival ranged from 0.35 to 0.95 (mean = 0.67) and increased along a southwest to northeast geographic axis. Further analysis of 6 datasets indicated no consistent difference in survival between males and females. Our results provide a better understanding of the relationship between survivorship and geography for the eastern massasauga and suggest that such variation should be incorporated into population models as well as local and regional management plans. © 2012 The Wildlife Society.
CHANGING SEDIMENT YIELD AND SEDIMENT DYNAMICS IN THE KAROO UPLANDS, SOUTH AFRICA; POST‐EUROPEAN IMPACTS
Authors: Foster I. D. L. , Rowntree K. M. , Boardman J. , Mighall T. M.
Published: July 2012

We provide an overview of published results and a significant body of new data from an ongoing research programme designed to reconstruct sediment yields and sources in small (<60 km2) catchments in the Eastern Cape, South Africa over the last 150 years. Our analysis of four catchments has determined that sediment yield increased significantly in the latter half of the 20th century but that the exact timing of these increases was different in each of the four catchments. In two high altitude locations, sediment yield increases were not associated with a significant change in sediment source although, in one case, areas of former cultivation appear to have made a slightly greater contribution since the 1960s. In a third catchment, increases in sediment yield appear to have been driven by the development of badlands and by an increase in connectivity between the badlands and the main channel network in the 1960s. In the fourth catchment, increased connectivity between the main catchment and dam occurred as a result of the construction of a causeway to carry a main road and by the construction of culverts beneath the road. Occasional changes in sediment source have also been identified in the sedimentary record, but these were not linked directly to road construction. Research to date shows the complexity of sediment delivery in these semi‐arid catchment systems and emphasises the need to combine sediment yield with source ascription to better understand the dynamics of these systems. Copyright © 2012 John Wiley & Sons, Ltd.
Complex Sentence Processing: A Review of Theoretical Perspectives on the Comprehension of Relative Clauses
Authors: Gordon Peter C. , Lowder Matthew W.
Published: July 2012

A major goal of psycholinguistics is to gain a better understanding of how syntactically complex sentences are processed. Pursuit of this goal has frequently focused on the contrast between object‐ and subject‐extracted relative clauses (RCs). Although a large body of literature demonstrates that comprehension is more difficult for object RCs than for subject RCs, the proposed explanations for this processing asymmetry are diverse and hotly debated. This article reviews theoretical accounts of RC processing in terms of whether they characterize the critical differences in comprehension difficulty as arising from memory processes, interpretive processes, or processes tuned to the frequency with which different types of language are encountered.
Donor assessment scores: Relevance and complete irrelevance
Authors: Porrett Paige M. , ter Horst Matthijs , Shaked Abraham
Published: July 2012

Key Points

1. Donor assessment scores can be used to prognosticate recipient outcomes but are often not clinically relevant.

2. The donor risk index, the survival outcomes following liver transplantation score, and the Donor Model for End-Stage Liver Disease score have specific advantages and disadvantages with respect to accuracy and ease of use.

3. The significance of the donor assessment is undermined by an allocation system that sometimes limits ideal donor-recipient matching and whose sole objective is the minimization of wait-list mortality instead of the benefit of transplantation. Liver Transpl, 2012. © 2012 AASLD.
Bridging the gap: Advances in artificial liver support
Authors: Nyberg Scott L.
Published: July 2012

Key Points

1. The goals of liver support therapy include the following:

• To provide detoxification and synthetic function during liver failure.

• To remove or reduce the production of proinflammatory cytokines to correct the systemic inflammatory response of liver failure.

• To stimulate the regeneration of the injured liver and increase the likelihood of spontaneous recovery.

2. There is a large unmet need for a liver support device because of the shortage of organs for liver transplantation and the risks of major surgery.

3. Liver support devices can be divided into 2 groups: purely mechanical artificial devices and cell-based bioartificial devices. Both provide detoxification, but bioartificial liver devices provide the option of synthetic function and biotransformation activities that are not possible with a purely mechanical device.

4. An abundant high-quality supply of human hepatocytes is not currently available for liver cell therapy. However, such a supply is essential for successful bioartificial liver therapy. Novel options are under development for the unlimited production of high-quality human hepatocytes. Liver Transpl, 2012. © 2012 AASLD.
Diblock Copolymer Micelles with Ionic Amphiphilic Corona
Authors: Lysenko Evgeny A. , Kulebyakina Alevtina I. , Chelushkin Pavel S. , Zezin Alexander B.
Published: July 2012

Summary: Aqueous dispersions of diblock copolymer micelles with homogeneous hydrophobic core (polystyrene) and heterogeneous amphiphilic corona from ionic N‐ethyl‐4‐vinylpyridinium bromide (EVP) and hydrophobic 4‐vinylpyridine (4VP) units have been prepared at pH 9. The structure and dispersion stability of micelles as function of the ratio and distribution pattern of ionic and hydrophobic units in corona have been systematically studied by means of transmission electron microscopy, static and dynamic light scattering, UV‐spectrophotometry techniques. It was shown that gradual decrease of the quantity of EVP‐units in corona had no impact on micelle structure until its fraction was above 0.7. When EVP‐fraction dropped below this point noticeable changes in micelle mass and dimensions were observed. In the case of random distribution of 4VP and EVP units these changes were moderate in value and jump‐like in character. In the case of mictoarm (starlike) distribution of 4VP and EVP blocks changes were large in value and monotonous in character. The presented results may be of certain use for design of polymer micelles with nanosegregated corona.
2D Diffusion of Macromolecules Adsorbed on Glass Microspheres
Authors: Malinin A. S. , Rakhnyanskaya A. A. , Yaroslavov A. A.
Published: July 2012

Summary: It has been demonstrated that diffusion of polycation adsorbed on glass microspheres occurs without desorption of the macromolecules into the solution and, therefore, can be characterizerd as 2D‐diffusion. The diffusion coefficint is estimated to be 1.4 × 10−12 cm2/s.
Supramolecular Hydrogels Based on Silver Mercaptide. Self‐Organization and Practical Application
Authors: Pakhomov Pavel , Khizhnyak Svetlana , Ovchinnikov Maxim , Komarov Pavel
Published: July 2012

Summary: A novel supramolecular thixotropic hydrogel based on low‐concentrated solutions of L‐cysteine and silver nitrate is synthesized. Self‐organization and gelation in the system are studied experimentally by means of UV‐vis and FTIR spectroscopy, dynamic light scattering, rotational viscometry, transmission electron microscopy, as well as theoretically by quantum mechanics and molecular dynamics. A mechanism of the formation of the supramolecular hydrogel is suggested, potential application for medicinal purposes is considered.
Thermal Degradation of Adsorbed Bottle‐Brush Macromolecules: When Do Strong Covalent Bonds Break Easily?
Authors: Paturej Jaroslaw , Kuban Lukasz , Milchev Andrey , Rostiashvili Vakhtang G. , Vilgis Thomas A.
Published: July 2012

The scission kinetics of bottle‐brush molecules in solution and on an adhesive substrate is modeled by means of Molecular Dynamics simulation with Langevin thermostat. Our macromolecules comprise a long flexible polymer backbone with L segments, consisting of breakable bonds, along with two side chains of length N, tethered to segments of the backbone with grafting density σg. In agreement with recent experiments and theoretical predictions, we find that bond cleavage is significantly enhanced on a strongly attractive substrate even though the chemical nature of the bonds remains thereby unchanged. Our simulation results indicate that the mean life time $\langle \tau \rangle $ of covalent bonds decreases by more than an order of magnitude upon adsorption even for brush molecules with comparatively short side chains $N = 1 \div 4$. The distribution of scission probability along the bonds of the backbone is found to change significantly when the length and/or the grafting density of the side chains are varied. The tension, experienced by the covalent bonds is found to grow steadily with increasing σg. The mean life time $\langle \tau \rangle $ declines with growing contour length L as $\langle \tau \rangle {\propto} L^{- 0.17} $, and also with growing side chain length N. The probability distribution of fragment lengths at different times is compatible with experimental observations and reveals a two‐stage (initially fast, then slow) process with different rates. The variation of the mean length L(t) of the fragments with elapsed time characterizes the thermal degradation process as a first order reaction.
Simulation of Complexes between a Charged Dendrimer and a Linear Polyelectrolyte with Finite Rigidity
Authors: Kłos Jarosław Sylwester , Sommer Jens Uwe
Published: July 2012

Complexes comprising a 4th‐generation dendrimer with 32 positively charged end‐groups and an oppositely charged linear polyelectrolyte along with explicit counterions are studied in an athermal solvent using MC simulations. The excluded volume between monomers, the full Coulomb potential between charges and the bending energy of the chain bonds are taken into account. The chain flexibility parameter is varied in a wide range, including the limiting cases of rigid and flexible chains. As the chains become more rigid, they take locally extended conformations within the complex. The conformations of the condensed chains are described in terms of loops, trains, and tails. In the limit of strong electrostatic coupling and high rigidity, long chains show a release of tails from the complex.

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QSPR Approach to Predict Nonadditive Properties of Mixtures. Application to Bubble Point Temperatures of Binary Mixtures of Liquids
Authors: Oprisiu I. , Varlamova E. , Muratov E. , Artemenko A. , Marcou G. , Polishchuk P. , Kuz'min V. , Varnek A.
Published: July 2012

This paper is devoted to the development of methodology for QSPR modeling of mixtures and its application to vapor/liquid equilibrium diagrams for bubble point temperatures of binary liquid mixtures. Two types of special mixture descriptors based on SiRMS and ISIDA approaches were developed. SiRMS‐based fragment descriptors involve atoms belonging to both components of the mixture, whereas the ISIDA fragments belong only to one of these components. The models were built on the data set containing the phase diagrams for 167 mixtures represented by different combinations of 67 pure liquids. Consensus models were developed using nonlinear Support Vector Machine (SVM), Associative Neural Networks (ASNN), and Random Forest (RF) approaches. For SVM and ASNN calculations, the ISIDA fragment descriptors were used, whereas Simplex descriptors were employed in RF models. The models have been validated using three different protocols: “Points out”, “Mixtures out” and “Compounds out”, based on the specific rules to form training/test sets in each fold of cross‐validation. A final validation of the models has been performed on an additional set of 94 mixtures represented by combinations of novel 34 compounds and modeling set chemicals with each other. The root mean squared error of predictions for new mixtures of already known liquids does not exceed 5.7 K, which outperforms COSMO‐RS models. Developed QSAR methodology can be applied to the modeling of any nonadditive property of binary mixtures (antiviral activities, drug formulation, etc.)
Photochemie im Kampf gegen Malaria
Authors: Kopetzki Daniel , Seeberger Peter H.
Published: July 2012

Artemisinin, der zurzeit effektivste Wirkstoff gegen Malaria, ließ sich bisher nur aus Pflanzen extrahieren. Er könnte Millionen Menschen retten, gäbe es einen einfachen und kostengünstigen Zugang zu diesem komplexen Naturstoff. Dieses Ziel ist nun in greifbare Nähe gerückt.
Kältemittel entflammt Widerstand
Authors: Osterath Brigitte
Published: July 2012

Eine organische Fluorverbindung namens R1234yf soll in Zukunft das Kältemittel in allen europäischen Autoklimaanlagen sein. Doch Behörden und Umweltorganisationen warnen, die europäische Chemikalienagentur fordert weitere Tests, und die EU leitet zudem noch ein Kartellrechtsverfahren ein.
Olefinmetathese — von E bis Z
Authors: Wegner Hermann A.
Published: July 2012

Die Olefinmetathese, eines der effizientesten Synthesewerkzeuge für den Aufbau komplexer Verbindungen, wird noch vielseitiger: Neue Katalysatoren ermöglichen die Synthese des energiereicheren Z‐Olefins.
Rastersondenmethoden für Polymere und Biomoleküle
Authors: Berger Rüdiger , Gutmann Jochen , Schäfer Rolf
Published: July 2012

Um weiche Materialien wie Biopolymere mit Rasterkraftmikroskopie zu untersuchen, sind die Methoden so anzupassen, dass die Sonde die Oberflächen nicht zerstört. Neben der Topografie erfasst die Rasterkraftmikroskopie weitere Informationen, beispielsweise lokale elektrische Eigenschaften und Bindungskräfte zwischen Molekülen.
Der Bachelor und die Industrie
Authors: Schmitz Karin
Published: July 2012

Wie kommen Unternehmen und Absolventen mit den Hochschulabschlüssen Bachelor und Master zurecht? In vielen größeren Unternehmen der Chemie‐ und Pharmabranche arbeiten Bachelors inzwischen erfolgreich. Allerdings sind sie meist FH‐Absolventen oder Absolventen eines dualen Studiengangs. Tätigkeitsfelder für Chemie‐Bachelors von den Universitäten gibt es in der Industrie es nicht.
Rapid Analysis of Volatile Components from Teucrium polium L. by Nanoporous Silica‐polyaniline Solid Phase Microextraction Fibre
Authors: Gholivand Mohammad Bagher , Piryaei Marzieh , Abolghasemi Mir Mahdi , Maassoumi Seyed Mohammad
Published: July 2012

Introduction

The development of simple, rapid and solvent‐free methods for the analysis of essential oils is highly desirable. Microwave‐assisted headspace solid‐phase microextraction (MA‐HS‐SPME) is a new sampling and concentration technique for the extraction of volatile components in medicinal plants. The main advantages of this method are the reduction of extraction time and of organic solvent.

Objective

A highly porous Santa Barbara amorphous (SBA‐15)/polyaniline material was prepared in order to produce a SPME fibre. The proposed fibre was evaluated for the extraction of the volatile component of Teucrium polium L.

Methodology

A homemade MA‐HS‐SPME apparatus was used for the extraction of volatile components. Highly porous SBA‐15/polyaniline materials were prepared for SPME. The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fibre.

Results

The SBA‐15/polyaniline nanonporous fibre could adsorb volatile components of T. polium efficiently. In comparison with a HD method, the proposed technique could equally monitor almost all the components of the sample, but in an easier way that was rapid and required a much lower amount of sample.

Conclusion

The experimental results showed that the nanoporous fibre was suitable for the semi‐quantitative study of the composition of essential oils in plant materials and monitoring the variations in the volatile components of the plants. Copyright © 2012 John Wiley & Sons, Ltd.
Preparation and characterization of polyvinylidene fluoride nanofibrous membranes by forcespinning™
Authors: Vazquez Beny , Vasquez Horacio , Lozano Karen
Published: July 2012

Nanofibers of polyvinylidene fluoride (PVDF) were prepared using solutions of PVDF with acetone and dimethylacetamide. The solutions were prepared at different concentrations (18, 21.5, and 25% wt) of PVDF. The nanofiber membranes were produced by using the Forcespinning™ method. Parameters such as the orifice size and spinneret angular velocity were varied. The produced membranes were characterized using scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction to determine the effect of varying parameters in the Forcespinning™ process on fiber diameter, bead formation, thermal stability, polymorphism, and morphology of the fibers and overall structure of the membrane. It was observed that polymer concentration played a key role in fiber and bead formation; at higher concentrations (such as 25 wt%), the fiber diameter increased but the bead formation decreased. The prepared composite membranes have potential applications on separators for Li‐ion batteries, ultra filtration membranes, and proton conductivity membranes for fuel cells applications. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Preparation and properties of heat curable blended methylfluorosilicone rubber
Authors: Liu Yuetao , Liu Hongzhi , Zhang Rong , Zhou Chuanjian , Feng Shengyu
Published: July 2012

Heat curable blended methylfluorosilicone rubber (MFSR) was prepared by combination of methylsilicone rubber (MSR) and fluorosilicone rubber (FSR). 2,5‐Bis(tert‐butylperoxy)‐2,5‐dimethylhexane (DBPMH) was chosen as a curing agent. Poly(methylsiloxane‐co‐fluorosiloxane) with low molecular weight was used as an interfacial agent. Curing characteristics, mechanical properties, low temperature performance, and hot oil resistance of blended MFSR was studied in details. The results showed that MSR and FSR could reach co‐vulcanization by DBPMH in blended MFSR. Higher FSR content could improve the scorch safety, lower the rate of curing reaction, and lead to the poor processability of blended MFSR. An increase of FSR content also improved the hot oil resistance of blended MFSR. Interfacial agent could limit the phase separation of MSR and FSR, make the blended system more thermodynamically stable and elevate the mechanical properties of blended MFSR. Differential scanning calorimetry (DSC) measurements revealed that increasing MSR content lowered the glass transition temperature (Tg) and improved the low‐temperature flexibility of blended MFSR when MSR was no more than 15%. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Surface‐modified talc particles by acetoxy groups grafting: Effects on mechanical properties of polypropylene/talc composites
Authors: Castillo Luciana A. , Barbosa Silvia E. , Capiati Numa J.
Published: July 2012

This article deals with the effects of surface‐modified talc particles on mechanical properties of polypropylene (PP)/talc composites. These materials were prepared by injection molding of PP blended with different concentrations of nontreated and treated talc, under the same processing conditions. Differential thermal calorimetry and scanning electron microscopy were used to assess thermal properties and morphology of the final composites. The reinforcing effect of talc, either treated or nontreated surface, on PP is analyzed through the tensile properties as a function of the mineral content (0–10 wt%). Morphological structure of composites revealed that the talc treatment improved the particle dispersion and distribution within the PP matrix and enhanced the interfacial PP‐talc adhesion. The mechanical properties of these composites, especially the Young modulus, tensile strength and elongation at break, were found to be improved respect to PP‐untreated talc ones. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Targeting to overexpressed glucose‐regulated protein 78 in gastric cancer discovered by 2D DIGE improves the diagnostic and therapeutic efficacy of micelles‐mediated system
Authors: Cheng Chun‐Chia , Lu Norman , Peng Cheng‐Liang , Chang Chun‐Chao , Mai Fu‐Der , Chen Ling‐Yun , Liao Mei‐Hsiu , Wang Wen‐Ming , Chang Jungshan
Published: July 2012

The survivals of gastric cancer (GC) patients are associated with early diagnosis and effective treatments. Therefore, it is urgent for the discovery of early GC biomarkers and tumor‐targeting therapeutics. The aim of this study was to uncover putative tissue biomarkers of GC using 2D DIGE and then apply one of these specific markers in GC treatment. We found three putative biomarkers of GC with significant differences in expression level compared to adjacent normal tissue, including glucose‐regulated protein 78 (GRP78) and glutathione s‐transferase pi (GSTpi) with increased expression level, and alpha‐1 antitrypsin (A1AT) with reduced expression level. The overexpressed GRP78 was used as a targeted protein for guiding the drugs to tumor cells, leading to more effective treatment for GC xenografts. Our results demonstrated that the designated GRP78‐binding peptide based on the sequence, WIFPWIQL, was selectively prone to recognize and bind to GC MKN45 cells in vitro, and also improve the delivery efficiency of polymeric micelles‐encapsulated drugs into tumor cells and displayed better therapeutic outcome in experimental animals. This strategy of GRP78‐mediated drug targeting system may bring chemotherapeutic drugs with more precise targeting to tumor cells, leading to minimize side effects on patients after chemotherapy.
Glial proteome changes in response to moderate hypothermia
Authors: Kim Jong‐Heon , Cho Young‐Eun , Seo Minchul , Baek Moon‐Chang , Suk Kyoungho
Published: July 2012

Reactive glia plays a central role in neuroinflammation associated with secondary damage after brain injury. In order to understand the global effects of therapeutic hypothermia on glial activation and neuroinflammation, we performed proteomic profiling of glial cultures following inflammatory stimulation and hypothermic exposure. Primary mixed glial cultures prepared from mouse brains were stimulated with lipopolysaccharide and interferon‐γ under normothermic (37°C) or moderate hypothermic (29°C) conditions, and their proteome profiles were compared by LC‐ESI‐MS/MS. Differentially expressed proteins were determined by high‐throughput label‐free quantification. Under hypothermic conditions, 64 and 16 proteins were upregulated (≥1.5‐fold) and downregulated (≤ 0.7‐fold), respectively, compared to normothermic conditions. More importantly, hypothermia altered the abundance of 143 proteins that were either increased or decreased by inflammatory stimulation. The results were validated for several proteins (ICAM‐1, STAT‐1, YWHAB, and IFIT‐3) by Western blot analysis. Pathway and network analysis indicate that hypothermia influences various biological functions of glia such as molecular transport, cell movement, immune response, cell death, and stress response. In conclusion, moderate hypothermia seems to have a significant effect on the protein expression profiles of brain glia and possibly ensuing neuroinflammation. These proteins may be involved in the protective mechanism of hypothermia against brain injuries.
Plasma Processing: Technology for the Batch Fabrication of Carbon Nanotube Film Electrodes for Biointerfaces
Authors: Kim Joon Hyub , Lee Myung Jin , Park Eun Jin , Lee Jun‐Yong , Lee Cheol Jin , Min Nam Ki
Published: July 2012

We review our research activity on the use of plasma processes for the batch fabrication of miniaturized single‐walled carbon nanotube (SWCNT) electrodes and their application to electrochemical biosensors. The SWCNT film was spray‐deposited onto a Pt support and exhibited excellent adhesion to the electrode. O2‐plasma patterning and subsequent activation of the deposited films realized efficient biointerfaces between SWCNTs and biomolecules. The film was integrated into miniaturized electrode systems for biosensor applications. The benefits of this new batch‐fabrication technology were demonstrated by the design and fabrication of integrated SWCNT three‐electrode systems on glass substrates. These systems had an effective area about six times that of untreated SWCNT, consistent with a significant increase in the peak current. Finally, the effectiveness of plasma‐processed SWCNT electrodes as biointerfaces was examined by detecting long target DNA sequences.

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Frontiers in pulmonary hypertension in infants and children with bronchopulmonary dysplasia
Authors: Collaco Joseph M. , Romer Lewis H. , Stuart Bridget D. , Coulson John D. , Everett Allen D. , Lawson Edward E. , Brenner Joel I. , Brown Anna T. , Nies Melanie K. , Sekar Priya , Nogee Lawrence M. , McGrath‐Morrow Sharon A.
Published: July 2012

Pulmonary hypertension (PH) is an increasingly recognized complication of premature birth and bronchopulmonary dysplasia (BPD), and is associated with increased morbidity and mortality. Extreme phenotypic variability exists among preterm infants of similar gestational ages, making it difficult to predict which infants are at increased risk for developing PH. Intrauterine growth retardation or drug exposures, postnatal therapy with prolonged positive pressure ventilation, cardiovascular shunts, poor postnatal lung and somatic growth, and genetic or epigenetic factors may all contribute to the development of PH in preterm infants with BPD. In addition to the variability of severity of PH, there is also qualitative variability seen in PH, such as the variable responses to vasoactive medications.

To reduce the morbidity and mortality associated with PH, a multi‐pronged approach is needed. First, improved screening for and increased recognition of PH may allow for earlier treatment and better clinical outcomes. Second, identification of both prenatal and postnatal risk factors for the development of PH may allow targeting of therapy and resources for those at highest risk. Third, understanding the pathophysiology of the preterm pulmonary vascular bed may help improve outcomes through recognizing pathways that are dysregulated in PH, identifying novel biomarkers, and testing novel treatments. Finally, the recognition of conditions and exposures that may exacerbate or lead to recurrent PH is needed to help with developing treatment guidelines and preventative strategies that can be used to reduce the burden of disease. Pediatr Pulmonol. 2012. 47:1042–1053. © 2012 Wiley Periodicals, Inc.
Neonatal non‐invasive respiratory support: Physiological implications
Authors: Shaffer Thomas H. , Alapati Deepthi , Greenspan Jay S. , Wolfson Marla R.
Published: July 2012

The introduction of assisted ventilation for neonatal pulmonary insufficiency has resulted in the successful treatment of many previously fatal diseases. During the past three decades, refinement of invasive mechanical ventilation techniques has dramatically improved survival of many high‐risk neonates. However, as with many advances in medicine, while mortality has been reduced, morbidity has increased in the surviving high‐risk neonate. In this regard, introduction of assisted ventilation has been associated with chronic lung injury, also known as bronchopulmonary dysplasia. This disease, unknown prior to the appearance of mechanical ventilation, has produced a population of patients characterized by ventilator or oxygen dependence with serious accompanying pulmonary and neurodevelopmental morbidity. The purpose of this article is to review non‐invasive respiratory support methodologies to address the physiologic mechanisms by which these methods may prevent the pathophysiologic effects of invasive mechanical ventilation. Pediatr Pulmonol. 2012. 47:837–847. © 2012 Wiley Periodicals, Inc.
Optimization of designed armadillo repeat proteins by molecular dynamics simulations and NMR spectroscopy
Authors: Alfarano Pietro , Varadamsetty Gautham , Ewald Christina , Parmeggiani Fabio , Pellarin Riccardo , Zerbe Oliver , Plückthun Andreas , Caflisch Amedeo
Published: July 2012

A multidisciplinary approach based on molecular dynamics (MD) simulations using homology models, NMR spectroscopy, and a variety of biophysical techniques was used to efficiently improve the thermodynamic stability of armadillo repeat proteins (ArmRPs). ArmRPs can form the basis of modular peptide recognition and the ArmRP version on which synthetic libraries are based must be as stable as possible. The 42‐residue internal Arm repeats had been designed previously using a sequence‐consensus method. Heteronuclear NMR revealed unfavorable interactions present at neutral but absent at high pH. Two lysines per repeat were involved in repulsive interactions, and stability was increased by mutating both to glutamine. Five point mutations in the capping repeats were suggested by the analysis of positional fluctuations and configurational entropy along multiple MD simulations. The most stabilizing single C‐cap mutation Q240L was inferred from explicit solvent MD simulations, in which water penetrated the ArmRP. All mutants were characterized by temperature‐ and denaturant‐unfolding studies and the improved mutants were established as monomeric species with cooperative folding and increased stability against heat and denaturant. Importantly, the mutations tested resulted in a cumulative decrease of flexibility of the folded state in silico and a cumulative increase of thermodynamic stability in vitro. The final construct has a melting temperature of about 85°C, 14.5° higher than the starting sequence. This work indicates that in silico studies in combination with heteronuclear NMR and other biophysical tools may provide a basis for successfully selecting mutations that rapidly improve biophysical properties of the target proteins.
Time‐resolved spectroscopy of carrier dynamics in graded ZnCdx O multilayer structures
Authors: Trunk Mareike , Venkatachalapathy Vishnukanthan , Zhang Tianchong , Azarov Alexander , Galeckas Augustinas , Kuznetsov Andrej Yu.
Published: July 2012

We report on time‐resolved photoluminescence studies of charge carrier dynamics in graded bandgap ZnCdxO (x=0‐60%) multilayers. Analysis of the spectral peak position and intensity under different excitation intensities and temperatures suggest excitonic origin of emission components forming a characteristic plateau in the region from 3.3 eV to 2.5 eV. The carrier recombination processes in ZnCdO alloys are found to be multi‐exponential with characteristic time constants spread from sub‐ nanosecond to microsecond time domains. Temperature dependencies of the radiative and non‐radiative recombination lifetime parameters have been extracted providing further evidence for the excitonic nature of the emission. Carrier dynamics in single and multilayer structures is compared and discussed in terms of surface and interface recombination also taking into account different photo‐generation profiles and their role in subsequent drift and diffusion processes. Generally lower lifetime and quantum efficiency parameters observed in multilayers suggest detrimental role of the interfaces in carrier relaxation process (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature quenching of PL intensity and mechanisms of carrier recombination in CdTe/ZnTe self‐assembled quantum dots
Authors: Reznitsky Alexander , Klochikhin Albert , Permogorov Sergei
Published: July 2012

We have studied the temperature dependence of the photoluminescence (PL) intensity of nano‐size heterostructures ZnTe/CdTe/ZnTe containing self‐organized CdTe quantum dots (QDs) in temperature range 5‐250 K at different intensities of optical excitation. It has been found that the temperature quenching of PL intensity is governed by thermal activation of electrons and holes to the centers of non‐radiative recombination.

These two processes should be considered as independent which leads to the two‐exponential character of the thermal decay curves. The character of temperature quenching of PL intensity strongly depends on the pumping power. The higher is the excitation power, the slower is the temperature decay of the PL intensity. We attribute the observed effect to the saturation of the centers of non‐radiative recombination for electrons or holes in the barrier regions of heterostructures. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Internal Pressure Test in Experiment and Simulation—Influence of the Wall Thickness Variation and the Change of the Packaging Behavior after the Impact of Standard Liquids
Authors: Menrad Andreas , Goedecke Thomas , Gruender Klaus‐Peter , Wagner Manfred H.
Published: July 2012

The effect of the wall thickness variation of blow‐moulded bodies made of high‐density polyethylene on an internal pressure test after prestoring the packaging with standard liquids was evaluated in experiments and simulations. The objects of the investigation were jerrycans used for the transportation and storage of dangerous goods.

The wall thickness was determined using two alternative methods to the magnetostatic measurement. These alternative methods are used for research purpose to get a volumetric model of the jerrycan wall as a geometric model for the simulation. The comparison of the experiments and the simulations of the internal pressure test were performed using the digital image correlation method. The integral strain and deformation of the whole jerrycan was detected by measuring the total mass of the jerrycan being filled with water during the internal pressure test. This is a suitable alternative to the optical measurements of local deformation by the digital image correlation method. Prestorage at 40 °C without the influence of chemicals strengthens the jerrycan, whereas the swelling effect of butyl acetate and hydrocarbon mixture softens the jerrycan. The comparison with the experiment is necessary to verify the accuracy of the simulation. It shows that the deformation can be simulated more precisely by using the actual measured geometry. The weakening of the high‐density polyethylene caused by a hydrocarbon mixture can be simulated using the Arrhenius equation. The aim of the simulation was to discover whether it is possible to use specimens to predict the behaviour of a packaging both after the influence of standard liquids. Copyright © 2012 John Wiley & Sons, Ltd.
Temperature effects of sputtering of Langmuir–Blodgett multilayers
Authors: Mao Dan , Brenes Daniel A. , Lu Caiyan , Wucher Andreas , Winograd Nicholas
Published: July 2012

Time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) and atomic force microscopy are used to characterize a wedge‐shaped crater eroded by a 40‐keV C60+ cluster ion beam on an organic thin film of 402 nm of barium arachidate multilayers prepared by using the Langmuir–Blodgett technique. Sample cooling at 90 K was used to help reduce chemical damage, to improve depth resolution and to maintain constant erosion rate during depth profiling. The film was characterized at 90, 135, 165, 205, 265 and 300 K. It is shown that sample cooling to 205 K or lower helps to inhibit erosion rate decay, whereas at 300 and 265 K, the erosion rate continues to drop after 250 nm of erosion, reaching approximately half of the initial value after removal of the entire film. Depth profiles are acquired from the SIMS images of the eroded wedge crater. The results suggest that sample cooling only slightly improves the altered layer thickness but eliminates the decrease in erosion rate observed at temperatures higher than 265 K. Copyright © 2012 John Wiley & Sons, Ltd.
Ultra high spatial resolution SIMS with cluster ions — approaching the physical limits
Authors: Kollmer Felix , Paul Wolfgang , Krehl Martin , Niehuis Ewald
Published: July 2012

We present state‐of‐the‐art time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) imaging with Bi primary ion clusters. The latest technological step pushes the lateral resolution into a region which has previously not been attained even by bombardment with mono‐atomic primary beams. We show high lateral resolution TOF‐SIMS images of line structures on certified reference samples and of real world samples. Moreover, we analyzed buried objects by prior removal of the covering material with the Bi cluster beam. Subsequent SIMS analysis of the vertical crater wall achieves a lateral resolution in the sub 50‐nm range at a depth of about 20 µm. Copyright © 2012 John Wiley & Sons, Ltd.
Wettability of dragonfly wings: the structure detection and theoretical modeling
Authors: Gao Chun‐Ying , Meng Gui‐Xian , Li Xin , Wu Ming , Liu Yang , Li Xiao‐Yu , Zhao Xin , Lee Imshik , Feng Xizeng
Published: July 2012

Hydrophobic surfaces have gained extensive attention in recent decades for their potential applications. The hydrophobic properties of dragonfly's (Pantala flavescens) wings were measured, and the water contact angles (WCAs) of the distal and basal part of a dragonfly's wing were 134.9° and 125.8°, respectively. Images obtained by optical microscopy and scanning electron microscopy showed the microstructures and nanostructures on the wing surface. Microstructures appeared as cell block patterns, and the size of the blocks decreased from the basal to distal part. However, no significant differences of chemical composition between the two parts were detected by X‐ray photoelectron spectroscopy. To understand the correlation between the structures and WCA, a double roughness structure model was built theoretically with simplified lattice patterns, and the theoretical model was well fitted with empirical wettability of the dragonfly's wing. Copyright © 2012 John Wiley & Sons, Ltd.
High Payload Dual Therapeutic‐Imaging Nanocarriers for Triggered Tumor Delivery
Authors: Kim Jin‐Ki , Yuan Hong , Nie Jingxin , Yang Yu‐Tsai , Leggas Markos , Potter Philip M. , Rinehart John , Jay Michael , Lu Xiuling
Published: July 2012

The in vitro and in vivo characterization of an optimized formulation of nanoparticles (NPs) loaded with a high content of dexamethasone palmitate (DEX‐P), a chemotherapeutic adjuvant that decreases interstitial fluid pressure in tumors, and 111In, a signaling agent, is described. These NPs are uniform in size and composition. Single photon emission computed tomography imaging demonstrates significant tumor uptake of 111In‐labeled DEX‐P NPs in tumor‐bearing mice. As with many nanoparticle‐based drug delivery systems, significant liver accumulation is observed. Assessment of liver histology and blood tests show no apparent hepatic or renal toxicity of the DEX‐P NPs. Conversion of DEX‐P to DEX occurs when DEX‐P NPs are incubated with mouse plasma, human tumor homogenate and ascites from tumor bearing mice, but not with human plasma. This conversion is slower in plasma from Es1e(‐/‐)/SCID mice, a potential alternative animal model that better mimics humans; however, plasma from these mice are not completely devoid of esterase activity. The difference between blood and tumor esterase activity in humans facilitates the delivery of DEX‐P NPs to tumors and the release of dexamethasone by an esterase trigger.
Superparamagnetic Iron Oxide Nanoparticles (SPION) for the Treatment of Antibiotic‐Resistant Biofilms
Authors: Taylor Erik N. , Kummer Kim M. , Durmus Naside Gozde , Leuba Kohana , Tarquinio Keiko M. , Webster Thomas J.
Published: July 2012

Bacterial infections caused by antibiotic‐resistant strains are of deep concern due to an increasing prevalence, and are a major cause of morbidity in the United States of America. In particular, medical device failures, and thus human lives, are greatly impacted by infections, where the treatments required are further complicated by the tendency of pathogenic bacteria, such as Staphylococcus aureus, to produce antibiotic resistant biofilms. In this study, a panel of relevant antibiotics used clinically including penicillin, oxacillin, gentamicin, streptomycin, and vancomycin are tested, and although antibiotics are effective against free‐floating planktonic S. aureus, either no change in biofilm function is observed, or, more frequently, biofilm function is enhanced. As an alternative, superparamagnetic iron oxide nanoparticles (SPION) are synthesized through a two‐step process with dimercaptosuccinic acid as a chelator, followed by the conjugation of metals including iron, zinc, and silver; thus, the antibacterial properties of the metals are coupled to the superparamagnetic properties of SPION. SPION might be the ideal antibacterial treatment, with a superior ability to decrease multiple bacterial functions, target infections in a magnetic field, and had activity better than antibiotics or metal salts alone, as is required for the treatment of medical device infections for which no treatment exists today.
A Carbon Nanotube Toxicity Paradigm Driven by Mast Cells and the IL‐33/ST2 Axis
Authors: Katwa Pranita , Wang Xiaojia , Urankar Rakhee N. , Podila Ramakrishna , Hilderbrand Susana C. , Fick Robert B. , Rao Apparao M. , Ke Pu Chun , Wingard Christopher J. , Brown Jared M.
Published: July 2012

Concern about the use of nanomaterials has increased significantly in recent years due to potentially hazardous impacts on human health. Mast cells are critical for innate and adaptive immune responses, often modulating allergic and pathogenic conditions. Mast cells are well known to act in response to danger signals through a variety of receptors and pathways including IL‐33 and the IL‐1‐like receptor ST2. Here, the involvement of mast cells and the IL‐33/ST2 axis in pulmonary and cardiovascular responses to multi‐walled carbon nanotube (MWCNT) exposure are examined. Toxicological effects of MWCNTs are observed only in mice with a sufficient population of mast cells and are not observed when mast cells are absent or incapable of responding to IL‐33. Our findings establish for the first time that mast cells and the IL‐33/ST2 axis orchestrates adverse pulmonary and cardiovascular responses to an engineered nanomaterial, giving insight into a previously unknown mechanism of toxicity. This novel mechanism of toxicity could be used for assessing the safety of engineered nanomaterials and provides a realistic therapeutic target for potential nanoparticle induced toxicities.