bluuebunny/crossref_metadata_2025 huggingface dataset:
A General, Highly Efficient Ullmann C‐O Coupling Reaction under Microwave Irradiation and the Effects of Water
Authors: Zhu Xin‐Hai , Chen Gong , Ma Yan , Song Hua‐Can , Xu Zun‐Le , Wan Yi‐Qian
Published: April 2007

A general, rapid and highly efficient method for the synthesis of diaryl ethers under the assistance of microwave irradiation was described. A series of diaryl ethers were prepared by direct coupling of phenols and aryl halides in good to excellent yields in anhydrous DMF or NMP at 150 °C within 20 min. The presence of water was found to have a significant impact on the Ullmann C‐O coupling reaction between aryl halides and phenols under microwave irradiation.
Synthesis and Structural Characterization of Alkali Metal Guanidinates
Authors: Luo Yun‐Jie , Zhang Yong , Shen Qi
Published: April 2007

Reactions of 1,3‐diisopropylcarbodiimide with alkali metal amides, MN(SiMe3)2 (M=Li or Na) in hexane or THF produced the alkali metal guanidinates {(i‐PrN)2C[N(SiMe3)2]Li}2 (1) and {(i‐PrN)2C[N(SiMe3)2]Na(THF)}2 (2) in nearly quantitative yields. Both complexes 1 and 2 were well characterized by elemental analysis, IR spectra, 1H and 13C NMR spectra, and X‐ray diffraction. It was found that the guanidinates adopt different coordination modes in these complexes.
Development of a superconducting magnet for nuclear magnetic resonance using bulk high‐temperature superconducting materials
Authors: Nakamura Takashi , Itoh Yoshitaka , Yoshikawa Masaaki , Oka Tetsuo , Uzawa Jun
Published: April 2007

We developed a trapped‐field magnet system using a bulk high‐temperature superconducting (HTS) material (Sm‐Ba‐Cu‐O; abbreviated as Sm123) and used it to observe a signal of 1H nuclear magnetic resonance (NMR). The compact magnet system can fit on a table and needs no conventional refrigerant such as liquid helium. The magnet has a c‐axis‐oriented single‐domain Sm123 bulk superconductor containing 20 wt.% Ag and was synthesized in the melt‐textured process. The magnet is constructed of two cylindrical pieces, 36‐mm outer and 7‐mm inner diameters, respectively, and 16‐mm thickness. This configuration results in magnetic field stability and suitable homogeneity for observation of NMR signal. The magnet was magnetized to 3 T by an ordinary NMR superconducting magnet by using a field cooling (FC) method. The bulk magnet was magnetized at 60K and has been kept at the temperature under 58K by using a pulse tube refrigerator. We observed 1H NMR signal from the silicon rubber with the size of 1.2 mm diameter and 1.5 mm length at 2.89 Tesla (123 MHz) and 228 kHz peak width. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 65–70, 2007.
Calculation of SAR for transmit coil arrays
Authors: Mao Weihua , Wang Zhangwei , Smith Michael B. , Collins Christopher M.
Published: April 2007

Transmit coil arrays allowing independent control of individual coil drives facilitate adjustment of the B1 field distribution, but when the B1 field distribution is changed the electric field and SAR distributions are also altered. This makes safety evaluation of the transmit array a challenging problem because there are potentially an infinite number of possible field distributions in the sample. Local SAR levels can be estimated with numerical calculations, but it is not practical to perform separate full numerical calculations for every current distribution of interest. Here we evaluate superposition of separate electric field calculations—one for each coil—for predicting SAR in a full numerical calculation where all coils are driven simultaneously. It is important to perform such an evaluation because the effects of coil coupling may alter the result. It is shown that while there is good agreement between the superimposed and simultaneous drive results when using current sources in the simulations, the agreement is not as good when voltage sources are used. Finally, we compare maximum local SAR levels for B1 field distributions that are either unshimmed or shimmed over one of three regions of interest. When B1 field homogeneity is improved in a small region of interest without regard for SAR, the maximum local SAR can become very high. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 127–131, 2007.
Interconnecting L/C components for decoupling and its application to low‐field open MRI array
Authors: Wu Bing , Qu Peng , Wang Chunsheng , Yuan Jing , Shen Gary X.
Published: April 2007

Interconnecting L/C components are often applied to decouple the array elements for parallel imaging. Although it has been recognized that interconnecting capacitors and inductors can both be employed for decoupling, quantitative study of this decoupling technique has not yet been presented. In this study, a theoretical analysis for the interconnecting L/C decoupling circuit is provided. The analysis reveals that the required decoupling capacitance decreases with the resonant frequency, whereas the decoupling inductance is independent of the frequency. The inductive decoupling scheme is applied in the design of a four‐channel knee coil for 0.5 T open MRI with vertical magnetic field. Experimental results show that good isolations (−19 dB ∼ −45 dB) between coil elements can be achieved and only 5% ∼ 11% degeneration of Q is caused by this decoupling method. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 116–126, 2007
Comparison of local and global arrays for MRI
Authors: Spence Dan K. , Wright Steven M.
Published: April 2007

Different array topologies are examined and compared in an effort to improve arrays for MRI and for SENSE imaging. The prerequisites for a good array are high intrinsic signal‐to‐noise ratio (SNR) and low noise amplification (g‐factor) during SENSE acquisitions. The merits of two classes of planar arrays are discussed—arrays composed of small elements with “local” sensitivity versus arrays made up of elements that have a “global” sensitivity over the entire field of view. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 86–94, 2007.
Titanium‐Containing Zeolites and Microporous Molecular Sieves as Photovoltaic Solar Cells
Authors: Atienzar Pedro , Valencia Susana , Corma Avelino , García Hermenegildo
Published: April 2007

Four titanium‐containing zeolites and microporous molecular sieves differing on the crystal structure and particle size (Ti/Beta, Ti/Beta‐60, TS‐1 and ETS‐10) are prepared, and their activity for solar cells after incorporating N3 (a commercially available ruthenium polypyridyl dye) is tested. All the zeolites exhibit photovoltaic activity, and the photoresponse is quite independent of the zeolite pore dimensions or particle size. The photoresponse increases with titanium content in the range 1–7 % wt. In this way, cells are obtained that have open‐circuit voltage Voc=560 mV and maximum short‐circuit photocurrent density Isc=100 μA, measured for 1×1 cm2 surfaces with a solar simulator at 1000 W through and AM 1.5 filter. These values are promising and comparable to those obtained for current dye‐sensitized titania solar cells.
Mechanische Verfahren zur Mauerwerkstrockenlegung – Horizontalabdichtung
Authors: Pech Anton
Published: April 2007

In den letzten Jahrzehnten hat sich eine Vielzahl an technischen Verfahren zur Mauerwerkstrockenlegung entwickelt, jedoch nur einige haben sich auch bewährt. Die “mechanischen Verfahren” sind dabei sicherlich am ehesten mit Abdichtungen im Neubau zu vergleichen, aber auch hier sind Rahmenbedingungen zu beachten, welche über Erfolg und Misserfolg der Systemanwendung entscheiden. In vielen Fällen wird auch der Fehler begangen, dass Verfahren zur Verhinderung oder Verminderung des kapillaren Feuchtigkeitsaufstieges, wie es bei einem mechanischen Verfahren der Fall ist, mit der “Trockenlegung” des Mauerwerkes verwechselt werden. Wesentliche Aspekte der mechanischen Verfahren sind die setzungsfreie Herstellung der nachträglichen Abdichtungsebene, auch unter Langzeitbeanspruchung sowie die Aufnahme von Horizontalkräften.
Erfolgskontrolle nachträglicher Maßnahmen gegen aufsteigende Feuchtigkeit
Authors: Simlinger Christian
Published: April 2007

Die unterschiedlichsten Verfahren werden als Maßnahmen gegen aufsteigende Feuchtigkeit im Mauerwerk angeboten und eingesetzt. Einige dieser Verfahren stützen sich auf Phänomene, deren Wirkungsweisen wissenschaftlich nicht bestätigt sind. Die durchgeführten Untersuchungen im Zuge der Erfolgskontrolle beschäftigen sich jedoch ausschließlich mit Verfahren, deren Wirkungsweisen naturwissenschaftlich allgemein anerkannt sind. Durch Kontrollmessungen an 40 Objekten, bei denen nachträgliche Maßnahmen gegen aufsteigende Feuchtigkeit durchgeführt wurden, soll ein Beitrag zur Verbesserung der Wirksamkeit und Dauerhaftigkeit der einzelnen Verfahren geliefert werden. Für die Versuchsdurchführung und die Beurteilung der Maßnahmen wurden die Bestimmungen der ÖNORM B 3355 herangezogen.
Hohlmauerwerkskonstruktionen – eine typische Bauweise des 19. Jahrhunderts
Authors: Weller Bernhard , Naumann Thomas
Published: April 2007

Das Hohlmauerwerk ist eine zweischalige Konstruktionsform des Ziegelmauerwerks, die in verschiedenen Regionen Deutschlands insbesondere im 19. Jahrhundert verbreitet war. Zur Herstellung von Wänden aus Hohlmauerwerk verwendete man häufig Vollziegel, welche in speziellen Verbänden so vermauert wurden, dass im Inneren planmäßige Hohlräume entstanden. Nachfolgend werden Hohlmauerwerkskonstruktionen des 19. Jahrhunderts in ihren typischen Konstruktionsformen und ihrer Entwicklung dargestellt. Die Ausführungen basieren dabei sowohl auf umfangreichen Bestandsaufnahmen an datierten Beispielgebäuden in Dresden und Umgebung als auch auf einer Quellenrecherche in Fachbüchern und Aufsätzen der Bauzeit.
Radioevaluation of PAMs, CMs, and PS‐Lip as an oral carrier for vaccine delivery into intestinal Peyer's patches
Authors: Lee Chang‐Moon , Heo Young‐Jun , Song Ho‐Chun , Bom Hee‐Seung , Lee Hyun‐Chul , Jeong Hwan‐Jeong , Lee Ki‐Young
Published: April 2007

The aim of the present study was to evaluate the utility of pullulan acetate microparticles (PAMs), chitosan micropaticles (CMs), and dipalmitoylphosphatidyl‐serine‐liposomes (PS‐Lip) as oral carriers for delivery to the intestinal Peyer's patches (PPs). To monitor PP delivery after oral administration, PAMs, CMs, and PS‐Lip were radiolabeled with 99mTc. Radiolabeling efficiencies of the particles were 95±2.5% (PAMs), 87±4.3% (CMs), and 77.2±5.8% (PS‐Lip). In delivery studies to the PPs, the percentage of PS‐Lip taken up to the PPs was 3.8 × 10−3±0.3% of the administered dose with PS‐Lip group showed significantly high uptake compared to the PAM and CM groups. These results suggest that PS‐Lip may be used as a potential system for developing an oral delivery carrier. Drug Dev. Res. 67:884–889, 2006. © 2007 Wiley‐Liss, Inc.
Recent development and potential use of µ‐ and κ‐opioid receptor ligands in positron emission tomography studies
Authors: Henriksen Gjermund , Willoch Frode , Talbot Peter S. , Wester Hans‐Jürgen
Published: April 2007

Quantitative non‐invasive imaging of target structures in the human central nervous system provided by positron emission tomography (PET) permits investigation of the relationship between molecular events and pharmacological effects in living humans. Due to their prominent role in opiate and stimulant drug misuse and dependence, as well as in nociceptive signaling, µ‐ and κ‐opioid receptors are potential targets for advances in neuro(psycho)pharmacological treatment of these illnesses and syndromes. In this review, we describe recent developments in specific positron emitting radiopharmaceuticals for these opioid receptor subclasses. Implications for further advances and clinical applications of the labeled ligands are discussed. Drug Dev. Res. 67:890–904, 2006. © 2007 Wiley‐Liss, Inc.
Joint source and channel coding: from the beginning until the ‘EXIT’
Authors: Hindelang Thomas , Adrat Marc , Fingscheidt Tim , Heinen Stefan
Published: April 2007

The speech quality in digital mobile communications is improved by using the residual redundancy after speech encoding in source decoding or channel decoding. The latter was investigated at the LNT at Munich University of Technology, the first idea at the IND at RWTH Aachen University. When the two institutes got aware of each other's results, a friendly scientific competition was started by investigating ‘source‐controlled channel decoding’ (SCCD) at the LNT and ‘source optimised channel codes’ (SOCC) at the IND. It turned out, a combination of the two separate approaches would be the best, which led to a fruitful cooperation. The outcome was the ‘joint source and channel coding’ approach, the iterative source and channel decoding (ISCD) and its improvement by applying the extrinsic information transfer (EXIT) chart analysis. In this paper we give a summary of the algorithms and their performances. We also take a look onto the application of the algorithms to real world systems. Copyright © 2007 John Wiley & Sons, Ltd.
Human cortical areas involved in sustaining perceptual stability during smooth pursuit eye movements
Authors: Trenner Maja U. , Fahle Manfred , Fasold Oliver , Heekeren Hauke R. , Villringer Arno , Wenzel Rüdiger
Published: April 2007

Because both, eye movements and object movements induce an image motion on the retina, eye movements must be compensated to allow a coherent and stable perception of our surroundings. The inferential theory of perception postulates that retinal image motion is compared with an internal reference signal related to eye movements. This mechanism allows to distinguish between the potential sources producing retinal image motion. Referring to this theory, we investigated referential calculation during smooth pursuit eye movements (SPEM) in humans using event‐related functional magnetic resonance imaging (fMRI). The blood oxygenation level dependent (BOLD) response related to SPEM in front of a stable background was measured for different parametric steps of preceding motion stimuli and therefore assumed for different states of the referential system. To achieve optimally accurate anatomy and more detectable fMRI signal changes in group analysis, we applied cortex‐based statistics both to all brain volumes and to defined regions of interest. Our analysis revealed that the activity in a temporal region as well as the posterior parietal cortex (PPC) depended on the velocity of the preceding stimuli. Previous single‐cell recordings in monkeys demonstrated that the visual posterior sylvian area (VPS) is relevant for perceptual stability. The activation apparent in our study thus may represent a human analogue of this area. The PPC is known as being strongly related to goal‐directed eye movements. In conclusion, temporal and parietal cortical areas may be involved in referential calculation and thereby in sustaining visual perceptual stability during eye movements. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Neural activity of the anterior insula in emotional processing depends on the individuals' emotional susceptibility
Authors: Iaria Giuseppe , Committeri Giorgia , Pastorelli Concetta , Pizzamiglio Luigi , Watkins Kate E. , Carota Antonio
Published: April 2007

Differences in personality factors between individuals may manifest themselves with different patterns of neural activity while individuals process stimuli with emotional content. We attempted to verify this hypothesis by investigating emotional susceptibility (ES), a specific emotional trait of the human personality defined as the tendency to “experience feelings of discomfort, helplessness, inadequacy and vulnerability” after exposure to stimuli with emotional valence. By administering a questionnaire evaluating the individuals' ES, we selected two groups of participants with high and low ES respectively. Then, we used functional magnetic resonance imaging to investigate differences between the groups in the neural activity involved while they were processing emotional stimuli in an explicit (focusing on the content of the stimuli) or an incidental (focusing on spatial features of the stimuli, irrespectively of their content) way. The results showed a selective difference in brain activity between groups only in the explicit processing of the emotional stimuli: bilateral activity of the anterior insula was present in subjects with high ES but not in subjects with low ES. This difference in neural activity within the anterior insula proved to be purely functional since no brain morphological differences were found between groups, as assessed by a voxel‐based morphometry analysis. Although the role of the anterior insula in the processing of contexts perceived as emotionally salient is well established, the present study provides the first evidence of a modulation of the insular activity depending on the individuals' ES trait of personality. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
P53‐specific T cell responses in patients with malignant and benign ovarian tumors: Implications for p53 based immunotherapy
Authors: Lambeck Annechien , Leffers Ninke , Hoogeboom Baukje‐Nynke , Sluiter Wim , Hamming Ineke , Klip Harry , ten Hoor Klaske , Esajas Martha , van Oven Magda , Drijfhout Jan‐Wouter , Platteel Inge , Offringa Rienk , Hollema Harry , Melief Kees , van der Burg Sjoerd , van der Zee Ate , Daemen Toos , Nijman Hans
Published: April 2007

Despite intensive treatment, 70% of the ovarian cancer patients will develop recurrent disease, emphasizing the need for new approaches such as immunotherapy. A promising antigenic target for immunotherapy in ovarian cancer is the frequently overexpressed p53 protein. The aim of the study was to evaluate the nature and magnitude of the baseline anti‐p53 immune response in ovarian cancer patients. P53‐specific T cell responses were detected in both half of the ovarian cancer patients as in the group of control subjects, consisting of women with benign ovarian tumors and healthy controls. Importantly, while in the control group p53‐specific immunity was detected among the CD45RA+ naïve subset of T cells only, the p53‐specific T‐cell responses in ovarian cancer patients were also present in the CD45RO+ memory T‐cell subset, suggesting that in the cancer patients sufficient amounts of cancer‐derived p53 was presented to induce the formation of a p53‐specific memory T‐cell response. Further characterization of the p53‐specific memory T‐cell responses revealed that in addition to the type 1 cytokine IFN‐γ also the type 2 cytokines IL‐4 and IL‐5, as well as the immunosuppressive cytokine IL‐10 were produced. Notably, p53‐specific T cells were not only detected in the peripheral blood, but also among tumor infiltrating lymphocytes and in tumor‐draining lymph nodes. In conclusion, the existence of a weak mixed T‐helper type 1 and 2 p53‐specific T‐cell repertoire supports the rationale of using p53 long peptides in vaccination strategies aiming at the induction of p53‐specific Th1/CTL immunity. © 2007 Wiley‐Liss, Inc.
Sunscreen use and increased duration of intentional sun exposure: Still a burning issue
Authors: Autier Philippe , Boniol Mathieu , Doré Jean‐François
Published: April 2007

Sunscreen use is often proposed for sun protection because of their ability to block UV‐induced sunburns (the sun protection factor – SPF). Among suntan seekers, however, risk of cutaneous melanoma may be increased because of extended sun exposure duration. We made a systematic review of the evidence linking sunscreen use to sun exposure duration. Five observational studies found that when sun exposure was associated with willingness to get a tan or to stay longer in the sun (i.e., intentional sun exposure), sunscreen use was associated with duration of sun exposure 13–39% longer. Paradoxically, sunburns tend to be more frequent among sunscreen users, probably because of greater natural sun sensitivity. When sun exposure was not intentional, sunscreen use did not increase time spent in the sun. Two European double‐blind randomized trials conducted among young sun seekers found daily sun exposure duration, especially sunbathing, 19–25% longer with use of SPF 30 than with use of SPF 10 sunscreens. One randomized trial in a holiday resort in France found a 3–13% increase in sun exposure duration with use of SPF 12 versus SPF 40 sunscreen. But, the SPF 12 groups used 3.6–4.2 more sunscreen than the SPF 40 group, and thus the actual SPF in the SPF 12 group was higher than in the SPF 40 groups. In conclusion, sunscreen use leads to longer duration of sun exposure when sun exposure is intentional, but not when sun exposure is non intentional. © 2007 Wiley‐Liss, Inc.
A template route to the preparation of mesoporous amorphous calcium silicate with high in vitro bone‐forming bioactivity
Authors: Li Xia , Shi Jianlin , Zhu Yufang , Shen Weihua , Li Hua , Liang Jian , Gao Jianhua
Published: April 2007

The mesoporous amorphous calcium silicate (MACS) was first synthesized using mesoporous silica SBA‐15 as both the template and silicon source, and Ca(NO3)2 as the calcium source. The MACS shows a well‐defined mesoporous structure with high specific surface area. In vitro bioactivity studies of the MACS were carried out by soaking it in simulated body fluid (SBF) solutions for 4 h up to 5 days. Owing to the high specific surface area and pore volume, the MACS had a significantly enhanced bone‐forming bioactivity compared with the conventional amorphous CaSiO3. The MACS did develop a carbonate‐containing hydroxyapatite (HCA) layer on the surface after being immersed in SBF for 4 h with near‐spherical agglomerated hydroxyapatite (HA) nanoparticles. At longer soaking times, the number of agglomerated HA particles increased and the surface structure of the samples became more compact. Such MACS could be useful in developing new biomaterials and may have potential use in implanting and drug delivery for tissue regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Characteristics and mechanical properties of acrylolpamidronate‐treated strontium containing bioactive bone cement
Authors: Li Z. Y. , Yang C. , Lu W. W. , Xu B. , Lam W. M. , Ni G. X. , Abbah S. A. , Yang F. , Cheung K. M. C. , Luk K. D. K.
Published: April 2007

The aim of the present study was to determine the influence of surface treatment on the mechanical properties of strontium‐containing hydroxyapatite (Sr‐HA) bioactive bone cement. Previously we developed an injectable bioactive cement (SrHAC) system composed of Sr‐HA powders and bisphenol A diglycidylether dimethacrylate (Bis‐GMA). In this study, the Sr‐HA powder was subjected to surface treatment using acrylolpamidronate, a bisphosphonate derivative, which has a polymerizable group, to improve the interface between inorganic filler and organic matrix by binding Sr‐HA and copolymerizing into the matrix. After surface treatment, the compression strength, bending strength, and stiffness of the resulting composites were defined by using a material testing machine (MTS) according to ISO 5833. The fracture surface of the bone cement specimen was observed with a scanning electron microscope. Invitro cytotoxicity of surface‐treated SrHAC was also studied using a tetrazolium‐based cell viability assay (MTS/pms) on human osteoblast‐like cells, the SaOS‐2 cell line. Cells were seeded at a density of 104/mL and allowed to grow in an incubator for 48 h at 37°C. Results indicated that after surface treatment, the compression strength and stiffness significantly improved by 22.68 and 14.51%, respectively. The bending strength and stiffness of the bioactive bone cement also showed 19.06 and 8.91% improvements via three‐point bending test. The fracture surface micromorphology after compression and bending revealed that the bonding between the resin to surface‐treated filler considerably improved. The cell viability indicated that the treated particles were nontoxic and did not inhibit cell growth. This study demonstrated a new surface chemistry route to enhance the covalent bonds between inorganic fillers and polymer matrix for improving the mechanical properties of bone cement. This method not only improves the overall mechanical performance but also increases osteoblastic activity. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Defining sustainability: a conceptual orientation
Authors: Vos Robert O.
Published: April 2007

Despite the ubiquity of the concept of sustainability, defining the term and construing meaning for different contexts is difficult. This paper presents several archetypes of sustainability that are useful for classifying and understanding existing definitions. Definitions that emphasize one part or another of the core concept of sustainability will be necessary at varying scales and in different contexts. This paper presents a conceptual guide that contrasts a dominant paradigm of economic growth and development with ‘thick’ and ‘thin’ versions of sustainability. Definitions of sustainability are explored in terms of their orientation to the ontology of nature, substitutability of resources, economic growth, population growth, role of technology, and social equity. Copyright © 2007 Society of Chemical Industry
Assessing chemical oxygen demand and nitrogen conversions in a multi‐stage activated sludge plant with alternating aeration
Authors: Lessard Paul , Tusseau‐Vuillemin Marie‐Hélène , Héduit Alain , Lagarde Fabienne
Published: April 2007

This paper provides a detailed investigation of the mass transfers involved in chemical oxygen demand (COD) and N removal in an intermittent aeration activated sludge plant, as described by the widely used ASM1 model. The model was calibrated and validated on a data set obtained during three intensive sampling campaigns. The mass transfers of COD and nitrogen were calculated with the calibrated model for every biodegradable variable of the model in each tank of the biological treatment. Only by making this balance can evaluation of the contribution of each reactor (anaerobic, anoxic and intermittently aerated) to carbon and nitrogen removal be done. It was pointed out that in such a plant (activated sludge under very low organic mass loading (F/M) ratios, sludge retention time of 30 days) operating at 20 °C, the contribution of the anoxic tank in the denitrification process is very low (only 17%). The oxygen transfer in this tank was also estimated and found partly responsible for the low denitrification efficiency. Copyright © 2007 Society of Chemical Industry
Removal of organic contaminants from water using nanosponge cyclodextrin polyurethanes
Authors: Mhlanga Sabelo D , Mamba Bhekie B , Krause Rui W , Malefetse Tshepo J
Published: April 2007

Insoluble nanoporous cyclodextrin (CD) polymers were synthesized using bifunctional isocyanate linkers. The ability of these polymers to remove selected organic pollutants from water at varying concentrations was studied. The investigated pollutants were selected high‐priority chlorinated disinfection by‐products (DBPs) and a common odour‐causing compound in water, 2‐methylisoborneol (2‐MIB). The unpleasant musty odour imparted by 2‐MIB and geosmin in water can be detected by the human nose even at ng L−1 (parts per trillion) levels. Pre‐concentration and extraction of water samples containing low levels of pollutants was performed using solid phase extraction (SPE) and subsequently quantified by gas chromatography‐mass spectrometry (GC/MS). Here we show that the CD polymers demonstrate excellent absorption efficiency (>99%) with respect to the organic pollutants, considerably better than granular activated carbon (GAC). The recyclability efficiency of these CD polymers is also reported. Copyright © 2007 Society of Chemical Industry
Two and three‐parameter isothermal modeling for liquid‐phase sorption of Procion Blue H‐B by inactive mycelial biomass of Panus fulvus
Authors: Sathishkumar Muthuswamy , Binupriya Arthur Raj , Vijayaraghavan Kuppusamy , Yun Soon‐Il
Published: April 2007

Procion Blue H‐B (PBHB) was used as a model reactive dye for biosorption studies onto inactive/dead mycelial biomass of Panus fulvus. Process parameters like pH, contact time and temperature were optimized. pH 2, 150 min of contact time and 35 °C were found to be more favorable for maximum biosorption. Various two‐ and three‐parameter isotherms were employed to understand the biosorption process. Among the various two‐parameter isothermal models applied, the Langmuir isotherm showed the best fit and among the three‐parameter isothermal models, the Khan, Redlich–Peterson, Sips and Toth isotherm models showed similar fits and only the Koble–Corrigan model showed a poor fit. In kinetic studies, pseudo‐first‐order model fitted better than pseudo‐second‐order model. Maximum desorption was observed in alkaline pH, which reveals the possibility of a chemisorption mechanism involved in the removal of PBHB. Among the various desorption media assessed, 70% (v/v) acetone showed complete desorption of the sorbate from the sorbent. Scanning electron microscopy images revealed the non‐fibrous nature of the adsorbent. FT‐IR studies showed the existence of amine groups in the sorbent which are the major adsorbent sites for reactive dyes. Copyright © 2007 Society of Chemical Industry
Live attenuated Salmonella as a vector for oral cytokine gene therapy in melanoma
Authors: Agorio Caroline , Schreiber Fernanda , Sheppard Mark , Mastroeni Piero , Fernandez Marcelo , Martinez Miguel Angel , Chabalgoity Jose Alejandro
Published: April 2007

Systemic administration of cytokines has shown therapeutic benefits in cancer patients; however, serious adverse effects associated with direct protein administration prevent the wide use of this approach. We have assessed the capacity of live attenuated Salmonella to act as a vector for oral cytokine‐gene therapy. Salmonella orally administered to melanoma‐bearing mice was found to accumulate within the tumor, reaching up to 105 bacteria per gram of tumor by day 21 after bacterial inoculation. Numbers of bacteria recovered from tumor did not differ from those recovered from liver or spleen at any time point. Recombinant bacteria carrying eukaryotic expression vectors encoding the murine IL‐4 or IL‐18 genes were administered to groups of mice with established subcutaneous melanoma tumors. We found that a single oral dose of Salmonella carrying any of the cytokine‐encoding plasmids resulted in significantly increased survival time, as compared with mice that received Salmonella carrying the parental plasmid or PBS. Increased levels of IFNγ were found in sera of animals receiving either of the cytokine‐encoding bacteria, but not in mice receiving Salmonella alone or PBS. Co‐administration of both recombinant bacteria maximized the production of IFNγ. Overall these results suggest that cytokine‐encoding Salmonella can be an effective and safer alternative to systemic administration of cytokines for immunotherapy of cancer. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of polyethylene glycol and magnesium sulfate administration on clinically relevant neurological outcomes after spinal cord injury in the rat
Authors: Ditor David S. , John Sunil M. , Roy Josee , Marx Jeffrey C. , Kittmer Colin , Weaver Lynne C.
Published: April 2007

The purpose of this study was to determine the long‐term effects of polyethylene glycol (PEG) and magnesium sulfate (MgSO4) on clinically relevant motor, sensory, and autonomic outcomes after spinal cord injury (SCI). Rats were injured by clip compression (50 g; T4) and treated 15 min and 6 hr postinjury intravenously (tail vein) with PEG (1 g/kg, 30% w/w in saline; n = 11), MgSO4 (300 mg/kg; n = 5), PEG + MgSO4 (n = 6), or saline (n = 10). Behavioral testing lasted for 6 weeks, followed by histological analysis of the spinal cord. Both PEG and MgSO4 resulted in enhanced locomotor recovery and lower susceptibility to neuropathic pain (mechanical allodynia) compared with saline. At 6 weeks, BBB scores were 7.3 ± 0.2, 7.7 ± 0.4, and 6.4 ± 0.6 in PEG‐treated, MgSO4‐treated, and saline‐treated control groups, respectively. Likewise, at 6 weeks PEG‐, MgSO4‐, and saline‐treated control animals showed 3.5 ± 0.4, 2.8 ± 0.9, and 5.0 ± 0.5 avoidance responses to at‐level touch, respectively. PEG + MgSO4 improved locomotor recovery and reduced pain but did not provide additional benefit compared with either treatment alone. Neither treatment, nor their combination, attenuated mean arterial pressure (MAP) increases during autonomic dysreflexia. However, saline‐treated controls had significantly lower resting MAP than PEG‐treated rats and tended to have lower resting MAP than MgSO4‐treated rats 6 weeks postinjury. MgSO4 treatment and PEG + MgSO4 treatment resulted in significant increases in dorsal myelin sparing, and the latter resulted in significant reductions in lesion volume, compared with saline‐treated controls. Furthermore, mean lesion volumes correlated negatively with the corresponding mean BBB scores and positively with the corresponding mean pain scores. In conclusion, both PEG and MgSO4 enhanced long‐term clinical outcomes after SCI. © 2007 Wiley‐Liss, Inc.
Glucose and hippocampal neuronal excitability: Role of ATP‐sensitive potassium channels
Authors: Huang Chin‐Wei , Huang Chao‐Ching , Cheng Juei‐Tang , Tsai Jing‐Jane , Wu Sheng‐Nan
Published: April 2007

Hyperglycemia‐related neuronal excitability and epileptic seizures are not uncommon in clinical practice. However, their underlying mechanism remains elusive. ATP‐sensitive K+ (KATP) channels are found in many excitable cells, including cardiac myocytes, pancreatic β cells, and neurons. These channels provide a link between the electrical activity of cell membranes and cellular metabolism. We investigated the effects of higher extracellular glucose on hippocampal KATP channel activities and neuronal excitability. The cell‐attached patch‐clamp configuration on cultured hippocampal cells and a novel multielectrode recording system on hippocampal slices were employed. In addition, a simulation modeling hippocampal CA3 pyramidal neurons (Pinsky‐Rinzel model) was analyzed to investigate the role of KATP channels in the firing of simulated action potentials. We found that incremental extracellular glucose could attenuate the activities of hippocampal KATP channels. The effect was concentration dependent and involved mainly in open probabilities, not single‐channel conductance. Additionally, higher levels of extracellular glucose could enhance neuropropagation; this could be attenuated by diazoxide, a KATP channel agonist. In simulations, high levels of intracellular ATP, used to mimic increased extracellular glucose or reduced conductance of KATP channels, enhanced the firing of action potentials in model neurons. The stochastic increases in intracellular ATP levels also demonstrated an irregular and clustered neuronal firing pattern. This phenomenon of KATP channel attenuation could be one of the underlying mechanisms of glucose‐related neuronal hyperexcitability and propagation. © 2007 Wiley‐Liss, Inc.
Axonal transport of neuropeptides: Retrograde tracing study in live cell cultures of rat sympathetic cervical ganglia
Authors: Li Jia‐Yi , Dahlström Annica
Published: April 2007

Previous studies demonstrated that neuropeptides are transported with fast axonal transport. Considerable amounts (30–40%) of anterogradely transported peptides accumulated distal to a crush, apparently recycling to the cell bodies. In the present study, we used primary and compartmented cultures of sympathetic cervical ganglia (SCG) to address questions on the origin of the recycling peptides. In primary cultures, distinct labeling of neuropeptide Y (NPY) or secretoneurin (SN) immunoreactivities was detected in varicosities and in cell bodies, after administration of NPY or SN antibodies to the living cultures. Simultaneous addition to the medium with antibody against the N‐terminal (lumen) domain of synaptotagmin, resulted in a partial overlapping between synaptotagmin and NPY/SN. In compartmented chamber cultures, in which cell body and proximal segments of the processes are restricted to the central chamber and the distal processes are present in peripheral compartments, antibody administration was performed in the peripheral compartment. KCl (60–120 mM) was added to the central chamber for 10 sec, followed by washing, and 30–60 min later clear labeling was detected in the cell bodies, suggesting that the antibodies were now present in structures that were transported from the distal segments in the peripheral compartment to the cell body. The results indicate 1) that peptide release from large dense cored vesicles is incomplete; 2) that the remaining peptides, together with the membrane, are retrogradely transported to cell bodies; and 3) that the recycling peptides accumulating distal to a crush of a peripheral nerve are most likely to be recycled from the nerve terminals. © 2007 Wiley‐Liss, Inc.
Dow's novel approach to managing the human element of mergers and acquisitions
Authors: Croyle Randolph M. , Johnsey Ava L.
Published: April 2007

The human element in mergers, acquisitions, and joint ventures is too critical to be left until late in the process. Dow's HR Center for M&As is on the scene early to uncover factors that could influence the viability and value of a deal, and then helps the business leaders plan and execute the implementation strategy. Having developed tried‐and‐true approaches, tools, and integrated HR solutions, along with practices for capturing key learnings from every deal, the center has become a repository of HR know‐how essential to a corporate growth strategy centered on M&As. © 2007 Dow Chemical Company
Enhanced histologic repair in a central wound in the anterior cruciate ligament with a collagen–platelet‐rich plasma scaffold
Authors: Murray Martha M. , Spindler Kurt P. , Ballard Percy , Welch Tyler P. , Zurakowski David , Nanney Lillian B.
Published: April 2007

The anterior cruciate ligament (ACL) of the knee is an intra‐articular ligament that fails to heal after primary repair. The medial collateral ligament (MCL) of the knee is an extra‐articular ligament that heals uneventfully in the majority of cases. Why these two ligaments have such different responses to injury remains unclear. In this article, we address two hypotheses: first, that the histologic response to injury is different in intra‐articular and extra‐articular ligaments, and second, that the response of the intra‐articular ligaments can be altered by placing a collagen–platelet‐rich plasma (collagen‐PRP) hydrogel in the wound site. Wounds were created in extra‐articular ligaments (MCL and/or patellar ligament) and an intra‐articular ligament (ACL) in canine knees, and the histologic response to injury evaluated at 3 days (n = 3), 7 days (n = 4), 3 weeks (n = 5), and 6 weeks (n = 5). In the 3‐week (n = 5) and 6‐week (n = 5) animals, bilateral central wounds were made in the ACLs and the wounds in one knee of each animal treated with a collagen‐PRP hydrogel while the contralateral side was untreated. Extra‐articular ligament wounds had greater filling of the wound site and increased presence in the wound site of fibrinogen, fibronectin, PDGF‐A, TGF‐β1, FGF‐2, and von Willebrand's factor when compared to intra‐articular ligament wounds. Treatment of the intra‐articular wound with a collagen‐PRP hydrogel resulted in increased filling of the wound site with repair tissue that had similar profiles of growth factor and protein expression to the extra‐articular ligament wounds. The use of a collagen‐PRP scaffold can ameliorate histologic differences noted between healing extra‐articular ligamentous wounds and nonhealing intra‐articular ligamentous wounds. This study supports the hypothesis that premature scaffold failure may play a key role in the normally expected failure of the ACL to heal after injury. Published by Wiley Periodicals, Inc. J Orthop Res 25:1007–1017, 2007
Expression of major vault protein gene in osteosarcoma patients
Authors: Dalla‐Torre Cristiane Arruda , de Toledo Silvia Regina Caminada , Yoshimoto Maisa , Petrilli Antônio Sérgio , Andrade Joyce Anderson Duffles , Chilton‐MacNeill Susan , Squire Jeremy A. , Zielenska Maria
Published: April 2007

Osteosarcoma (OS) is a primary malignant tumor of bone. Despite the successful use of multiple chemotherapeutic agents in the treatment of OS, more than 30% of OS tumors remain resistant to treatment. Elucidation of cellular resistance mechanisms may lead to better treatments for cancer patients. In this study, we used the low‐density expression cDNA array, GEArray Q Series Human Cancer Drug Resistance and Metabolism Gene Array to screen genes related to drug resistance in 15 OS tumors. Expression patterns of the MPV gene were validated by real time PCR on 45 OS patient tumor samples and correlated with clinical and pathological data. Major vault protein (MVP) expression was present in 24 (53%) tumor samples and absent in 21 (47%). Samples from surgery showed correlation between the expression of MVP, metastatic disease at diagnosis and event free survival (EFS). The MVP gene expression correlates with metastatic disease at diagnosis after neoadjuvant chemotherapy (p = 0.048), and is also associated with worse EFS (p = 0.036). These findings suggest that MVP expression is involved in one of the mechanisms of drug resistance in OS and is induced by chemotherapy. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:958–963, 2007
Early lesions of osteochondrosis in the distal tibia of foals
Authors: Olstad Kristin , Ytrehus Bjørnar , Ekman Stina , S. Carlson Cathy , Dolvik Nils I.
Published: April 2007

Material available for research into osteochondrosis (OC) in humans tends to represent chronic lesions. Comparative studies of early lesions in young animals are, therefore, important in clarifying the pathogenesis of OC in humans. Recent studies in pigs provide strong evidence that lesions of articular OC are associated with a focal failure in the cartilage canal vascular supply to epiphyseal growth cartilage (articular–epiphyseal cartilage complex excluding the articular cartilage). The purpose of the present study was to examine histological sections from a specific predilection site for articular OC in the distal tibia of a large number of young foals to determine if the same is true in horses. Material from the distal tibiae of 100 foals aged from 191 days of gestation to 153 days old was collected from routine submissions of fetuses and foals for post mortem examination. The tibiae were band‐sawed into slabs, and selected slabs were processed for histology, stained with hematoxylin and eosin, and examined using light microscopy. Early subclinical developmental stages of OC were found in the most common site for clinical OC lesions of horses in nine of 100 foals aged 12 to 122 days old. All lesions contained areas of chondrocyte necrosis that were associated with cartilage canal necrosis in five of nine foals. Five of these foals also had focal disruption of enchondral ossification at the chondro–osseous junction in the same site. Early lesions purported to play a role in the initial stages of articular OC in the distal tibia of horses were characterized by chondrocyte necrosis and likely occurred secondary to a failure of cartilage canal vascular supply to epiphyseal growth cartilage. The similarities in appearance between early lesions of piglets and foals suggest that information gained in one species may be transferable to others, including humans. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1094–1105, 2007
Improved accuracy of navigated drilling using a drill alignment device
Authors: Kendoff Daniel , Citak Musa , Gardner Michael J. , Stübig Timo , Krettek Christian , Hüfner Tobias
Published: April 2007

Drilling procedures are common in orthopedic surgery and are one specific task that may be aided by computer‐assisted navigation. However, the inherent flexibility of drill bit bending may make this the limiting factor in achieving acceptable accuracy when using these systems. We designed an alignment device that was fit to a standard orthopedic drill that allowed an extension of the stabilizing point of a drill bit. In foam blocks with a similar density as cancellous bone, 208 total navigated drilling trials were performed, using four different sized drill bits (2.5, 3.2, 3.5, and 4.5 mm) with and without the alignment device. Drilling tracts of 80 mm were made towards an intended target on the other side of the block. Reduction in deviation from the intended target was significantly improved with the use of the guide, ranging from 33% to 45% for the four drill sizes. For the trails using the alignment device, the 2.5‐mm drill bit was significantly less accurate than the three larger drills. Our results demonstrate that the use of external devices to augment drill bit stabilization can improve drilling accuracy. This may have particular importance when using navigation systems to drill into small anatomic confines. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:951–957, 2007
Water/Ethanol Selectivity of New Organic‐Inorganic Hybrid Membranes Fabricated from Poly(vinyl alcohol) and an Oligosilane
Authors: Uragami Tadashi , Yanagisawa Shohei , Miyata Takashi
Published: April 2007

To control the swelling of PVA membranes, mixtures of PVA and an inorganic oligosilane were prepared using sol‐gel reactions to yield new PVA/oligosilane hybrid membranes. In the separation of an ethanol/water azeotropic mixture during pervaporation, the effect of the oligosilane content on the water/ethanol selectivity of PVA/oligosilane hybrid membranes was investigated. The water/ethanol selectivity of PVA/oligosilane hybrid membranes was higher than that of PVA membranes, but the water/ethanol selectivity of hybrid membranes decreased with increasing oligosilane content. In order to increase the water/ethanol selectivity, PVA/oligosilane hybrid membranes were annealed. The water/ethanol selectivity of annealed PVA/oligosilane hybrid membranes was greater than un‐annealed hybrid membranes, and significantly governed by the oligosilane content, which could be attributed to both sorption and diffusion selectivities. The relationship between the structure of un‐annealed and annealed PVA/oligosilane hybrid membranes along with permeation and separation characteristics of an ethanol/water azeotropic mixture during pervaporation are discussed in detail.

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Synthesis of Saccharide‐Terminated Poly(ε‐caprolactone) via Michael Addition and ‘Click’ Chemistry
Authors: Xu Ning , Lu Feng‐Zhu , Du Fu‐Sheng , Li Zi‐Chen
Published: April 2007

Maleimido‐terminated PCL (M‐PCL) and alkyne‐terminated PCL (A‐PCL) are prepared by the ring‐opening polymerization of ε‐caprolactone with N‐hydroxyethyl maleimide and 4‐pentyn‐1‐ol as initiators catalyzed by tin(II) trifluoromethane sulfonate at 25 °C, respectively. A series of saccharide‐terminated PCLs have also been synthesized under mild conditions by two chemical strategies: 1). Michael addition of M‐PCL and amino‐containing maltose, and 2). a ‘click’ reaction of A‐PCL and azide‐containing saccharide. The amphiphilic nature of these maltose‐terminated PCLs make self‐assembly into aggregates in water possible. These aggregates have been characterized by transmission electron microscopy and dynamic light scattering measurements.

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