bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology development for single‐site ethylene copolymers in rotational molding
Authors: Xu H. , Bellehumeur C. T.
Published: September 2007

The morphology development of ethylene copolymers was modeled with the modified phase‐field theory. The metastability of polymer crystallization was also considered in the modeling. Modeling and experimental work were simultaneously undertaken to compare the crystallization kinetics of single‐site‐catalyzed and Ziegler‐catalyzed resins and their influence on morphology development in the rotational‐molding process. With a more uniform short‐chain branch distribution, the single‐site copolymers developed well‐defined spherulitic structures. The Ziegler–Natta catalyst resins were characterized by a higher nuclei density and a faster crystallization rate and produced finer structures in the molded parts. The modeling approach proposed in our work allowed an evaluation of the processing and the material effects on the development of morphological features during melt solidification. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Reactivity and efficiency of difunctional radical photoinitiators
Authors: Dietlin C. , Lalevee J. , Allonas X. , Fouassier J. P. , Visconti M. , Bassi G. Li , Norcini G.
Published: September 2007

Three difunctional cleavable photoinitiators based on the α‐hydroxyketone structure were tested in photopolymerization reactions with Fourier transform infrared spectroscopy. The excited‐state processes were investigated with time‐resolved laser absorption spectroscopy and laser‐induced photocalorimetry, which allowed the cleavage quantum yields to be determined and estimates of the triplet‐state lifetimes and interaction rate constants with a methacrylate monomer to be given. Modeling calculations helped to describe the ground‐state properties and showed that the difunctional photoinitiators exhibited different chromophoric groups than the corresponding monofunctional photoinitiator. An examination of the photochemical reactivity versus the practical efficiency observed in the polymerization showed that these difunctional photoinitiators exhibited better efficiency than the parent molecule, mainly because of their increased absorption properties. Their practical efficiency appeared to be better because of better light absorption when standard polychromatic light sources were used. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Viscoelasticity of epoxy resin/silica hybrid material prepared via sol–gel process: Considered in terms of morphology
Authors: Araki Wakako , Adachi Tadaharu
Published: September 2007

We investigated the relationship between the morphology and viscoelasticity of epoxy/silica hybrid materials manufactured via two different processes: simultaneous formation of epoxy and silica phases and sequential formation of silica phase in the prepared epoxy phase. The glass transition phenomena of the hybrid materials mostly depended on their silica structure. The particular structure did not affect Tg much, while the silica chain structure greatly raised Tg of the hybrid samples. The storage modulus E′ depended on the volume fraction of the silica phase ζ, rather than the silica structure. In the glassy state, E′ of the hybrid samples slightly decreased when compared with the neat epoxy samples. Lack of chemical reaction between the silica and the epoxy phases could be attributed to this decrease at which the silica structure could have worked as a flaw. In the rubbery state, E′ greatly increased with increasing silica content ζ regardless of the silica structure, and this behavior well agreed with that predicted by the Davies model, because the physical interaction worked very well in the rubbery region. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and properties of glucosamine and carboxymethylchitin from shrimp shell
Authors: Santhosh Sethumadhavan , Mathew Paruthapara T.
Published: September 2007

Export of processed and frozen shrimp products is the backbone of seafood industries. But, shrimp processing industries give rise to a large amount of waste materials. These waste products generate serious pollution hazards. A wise method to minimize environmental threats from prawn processing waste is to convert them in to useful products. Shrimp shell waste can be economically converted to chitin, a mucopolysaccharide. This marine polysaccharide and its derivatives hold a major part in our lives as medicines, cosmetics, textiles, paper, food and other branches of industry because of their unique nature in properties such as low toxicity, biocompatibility, hydrophobicity, etc. Hydrolysis of chitin yields a value added product, Glucosamine. Carboxymethylchitin is another derivative of chitin, prepared by the carboxymethylation reaction. This review article is an attempt to give an idea about the preparation, properties, and applications of the derivatives of chitin viz., glucosamine and carboxymethylchitin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of ethylene and norbornene copolymer with metallocene catalysts and characteristic analysis
Authors: Yao Zhen , Lv Fei , Liu Shao‐Jie , Cao Kun
Published: September 2007

To synthesis ethylene (E) and norbornene (NB) copolymer with high glass transition temperature and transparency, three metallocene catalysts with different symmetric structure were evaluated, respectively. The catalyst activity, NB fraction in copolymer and the transparency of copolymers produced under various conditions were investigated. It has been found that C2 symmetric catalyst such as rac‐[En(Ind)2]ZrCl2 was the best choice to produce copolymer with high NB fraction while keeping high catalyst activity. Furthermore, the effects of reaction conditions on activity of rac‐[En(Ind)2]ZrCl2 and the resultant copolymer structure have also been thoroughly studied. The results indicate that increasing the NB/E ratio is the effective way to increase NB content of copolymer when NB/E ratio is less than 20. However, when NB/E ratio is over 20, further increase in NB/E ratio will lead to significant lower catalyst activity and very limited increase in NB content of copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Novel nanoporous membranes from regenerated bacterial cellulose
Authors: Phisalaphong Muenduen , Suwanmajo Thapanar , Sangtherapitikul Preecha
Published: September 2007

Bacterial cellulose (BC) in an NaOH/urea aqueous solution was used as a substrate material for thefabrication of a novel regenerated cellulose membrane. The dissolution of BC involved swelling BC in a 4 wt % NaOH/3 wt % urea solution followed by a freeze–thaw process. The BC solution was cast onto a Teflon plate, coagulated in a 5 wt % CaCl2 aqueous solution, and then treated with a 1 wt % HCl solution. Supercritical carbon dioxide drying was then applied to the formation of a nanoporous structure. The physical properties and morphology of the regenerated bacterial cellulose (RBC) films were characterized. The tensile strength, elongation at break, and water absorption of the RBC membranes were 4.32 MPa, 35.20%, and 49.67%, respectively. The average pore size of the RBC membrane was 1.26 nm with a 17.57 m2/g surface area. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials
Authors: Seó Rosangela Seiko , Vergani Carlos Eduardo , Giampaolo Eunice Teresinha , Pavarina Ana Cláudia , Reis José Maurício dos Santos Nunes , Machado Ana Lucia
Published: September 2007

This study evaluated the influence of microwave disinfection on the strength of intact and relined denture bases. Water sorption and solubility were also evaluated. A heat‐polymerized acrylic resin (Lucitone 550) was used to construct 4‐mm‐thick (n = 40) and 2‐mm‐thick (n = 160) denture bases. Denture bases (2‐mm) were relined with an autopolymerizing resin (Tokuso Rebase Fast, Ufi Gel Hard, Kooliner, or New Truliner). Specimens were divided into four groups (n = 10): without treatment, one or seven cycles of microwave disinfection (650 W for 6 min), and water storage at 37°C for 7 days. Specimens were vertically loaded (5 mm/min) until failure. Disc‐shaped specimens (50 mm × 0.5 mm) were fabricated (n = 10) to evaluate water sorption and solubility. Data on maximum fracture load (N), deflection at fracture (mm), fracture energy (N mm), water sorption (%), and solubility (%) were analyzed by two‐way analysis of variance and Student–Newman–Keuls tests (α = 0.05). One cycle of microwave disinfection decreased the deflection at fracture and fracture energy of Tokuso Rebase Fast and New Truliner specimens. The strength of denture bases microwaved daily for 7 days was similar to the strength of those immersed in water for 7 days. Microwave disinfection increased the water sorption of all materials and affected the solubility of the reline materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Hierarchy crystallization structure of a polypropylene random copolymer injection‐molded bar induced by a nucleating agent
Authors: Wang Yong , Gao Yao , Shi Jing
Published: September 2007

In this work, the effect of a nucleating agent on the crystallization structure of an injection‐molded bar of a polypropylene random copolymer (PPR) with sorbitol derivatives [1,2,3,4‐dibenzylidene sorbitol (DBS)] has been studied. The results show that pure PPR forms a simple skin–core crystallization structure. However, PPR/DBS forms an interesting and complicated hierarchy crystallization structure: there is a transition layer between the skin layer and the core zone. In this transition layer, the crystallization structure consists of some perfect spherulites and many tiny crystallites. Further research suggests that the formation of the hierarchy crystallization structure depends on not only the content of the nucleating agent in the PPR matrix but also the mold temperature during the injection‐molding processing. The crystallization behavior of PPR/DBS during the cooling process has been characterized with polarization optical microscopy and differential scanning calorimetry. The results suggest that there are different mechanisms in the crystallization process of PPR/DBS. The formation of a three‐dimensional DBS network under a certain condition might be the main reason for the complicated hierarchy crystallization structure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Importance of RNA‐protein interactions in bacterial ribonuclease P structure and catalysis
Authors: Smith J. Kristin , Hsieh John , Fierke Carol A.
Published: September 2007

Ribonuclease P (RNase P) is a ribonucleoprotein (RNP) complex that catalyzes the metal‐dependent maturation of the 5′ end of precursor tRNAs (pre‐tRNAs) in all organisms. RNase P is comprised of a catalytic RNA (P RNA), and at least one essential protein (P protein). Although P RNA is the catalytic subunit of the enzyme and is active in the absence of P protein under high salt concentrations in vitro, the protein is still required for enzyme activity in vivo. Therefore, the function of the P protein and how it interacts with both P RNA and pre‐tRNA have been the focus of much ongoing research. RNA‐protein interactions in RNase P serve a number of critical roles in the RNP including stabilizing the structure, and enhancing the affinity for substrates and metal ions. This review examines the role of RNA‐protein interactions in bacterial RNase P from both structural and mechanistic perspectives. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 329–338, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Conformational consequences of protein glycosylation: Preparation of O‐mannosyl serine and threonine building blocks, and their incorporation into glycopeptide sequences derived from α‐dystroglycan
Authors: Liu Mian , Borgert Andrew , Barany George , Live David
Published: September 2007

With the goal to investigate the structural impact of O‐mannosyl glycosylation on α‐dystroglycan, a glycoprotein that has an important role in the extracellular organization of muscle, glycopeptides derived from its mucin‐like sequence have been prepared by solid‐phase peptide synthesis. Two approaches have been explored to obtain needed mannosylated serine and threonine building blocks. With the α‐carboxyl group unprotected, and with tetraaceto‐1‐fluoro‐α‐D‐mannose as the sugar donor, the desired α‐O‐mannosyl‐Fmoc‐Ser/Thr formed, along with mannosyl ester isomers and the species with mannose attached to both hydroxyl and carboxyl functions. Relevant mechanistic questions and stability issues were elucidated. Alternatively, building blocks were made with the α‐carboxyl protected/activated as the pentafluorophenyl (Pfp) ester. Glycopeptides synthesized herein contained 5–9 residues, and featured one, two, and four consecutive Ser and/or Thr residues O‐glycosylated with mannose. Circular dichroism (CD) spectra for Man‐containing glycopeptides recorded in water show them to be not well ordered. For one of the α‐dystroglycan‐derived sequences, the comparative conformational consequences of glycosylation by either Man or GalNAc have been examined by CD and NMR, with both methods showing a more organized structure when GalNAc is present. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 358–368, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Clinicopathological significance of fibrous tissue around fixed recurrent rectal cancer in the pelvis
Authors: Uehara K , Shimoda T , Nakanishi Y , Taniguchi H , Akasu T , Fujita S , Yamamoto S , Moriya Y
Published: September 2007

Background

Fibrous tissue around a locally recurrent rectal tumour is an interesting histological feature, but its clinicopathological significance has not been investigated.

Methods

This retrospective study examined clinicopathological findings in 48 patients who underwent curative total pelvic exenteration with distal sacrectomy (TPES) between 1992 and 2004. Data were analysed with respect to fibrosis around the recurrent tumour, categorized into one of three groups: no fibrosis (f0), partial fibrosis (f1) or circumferential fibrosis (f2).

Results

Ten, 17 and 21 patients had f0, f1 and f2 fibrosis respectively, with 5-year survival of none, four and eight patients respectively. The overall survival of patients with circumferential fibrosis was significantly better than that in patients with no fibrosis (P = 0·003). Univariable analysis showed that a high level of sacrectomy (P = 0·036), absence of lymphatic invasion (P = 0·031) and circumferential fibrosis (P = 0·039) were significantly associated with better overall survival. In multivariable analysis, circumferential fibrosis (P = 0·031) and low serum carcinoembryonic antigen levels (P = 0·044) were independent factors for a favourable outcome.

Conclusion

The outcome of patients with locally recurrent rectal cancer after curative TPES appears to be better when circumferential fibrosis is present around the tumour.
Effect of collagen turnover and matrix metalloproteinase activity on healing of venous leg ulcers
Authors: Meyer F J , Burnand K G , Abisi S , TeKoppele J M , van Els B , Smith A
Published: September 2007

Background

The presence of fibrous tissue in poorly healing venous leg ulcers suggests abnormal collagen metabolism. The aim was to determine whether there were differences in collagen turnover and matrix metalloproteinase (MMP) activity between ulcers that healed, those that did not heal and normal skin.

Methods

Biopsies were taken from the ulcers of 12 patients whose venous ulcers went on to heal and 15 patients whose ulcers failed to heal despite 12 months of compression bandaging. Biopsies were taken from 15 normal controls. Collagen turnover (collagen III N-terminal propeptide (PIIINP) and degraded collagen), and total MMP, MMP-1 and MMP-3 activities were measured.

Results

PIIINP and degraded collagen levels were higher in ulcers that healed compared with lesions that failed to heal (P = 0·005 and P < 0·001 respectively) and normal skin (P = 0·003 and P < 0·001). MMP-1 activity was also higher in healing ulcers than resistant ulcers (P < 0·001) and normal skin (P < 0·001). Significantly more total MMP activity was present in all ulcers than in normal skin (P < 0·001), but there was no difference in total MMP (and MMP-3 activity) between ulcers that healed and those that did not.

Conclusion

Rapidly healing venous leg ulcers had increased collagen turnover and MMP-1 activity, which appeared to differentiate them from those that failed to heal within 12 months.
Minimally invasive surgery for pancreatic endocrine tumours
Authors: Fendrich V , Langer P
Published: September 2007

Especially if small, solitary and benign
Multicentre randomized clinical trial of mechanical bowel preparation in elective colonic resection (Br J Surg 2007; 94: 689–695)
Authors: Noble E J , Daniels I R
Published: September 2007

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved,appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Seamless transition in the twenty‐first century: Partnering to survive and thrive
Authors: Hoffman‐Johnson Gail
Published: September 2007

This chapter describes development and implementation of a strategic partnership between a community college and a premier engineering university to improve students' transition from the two‐year to the four‐year institution.
Partnering to move students into college and community‐oriented careers: The administration of justice department at East Los Angeles College
Authors: Kisker Carrie B. , Hauser Patrick
Published: September 2007

This chapter describes how the Administration of Justice Department at East Los Angeles College has partnered with community and educational organizations to move students into college and careers in law enforcement, criminal justice, and the fire service.
Stepping outside the big box high school: A partnership influenced by goals, capital, and decision making
Authors: Watson Jesse S.
Published: September 2007

This chapter describes a partnership among a K–12 school district, a community college, and a four‐year university. It focuses on the role that capital in various forms plays in the partnership.
Alliances among community colleges: Odd bedfellows or lasting partners?
Authors: Eddy Pamela L.
Published: September 2007

This chapter discusses the experiences of five two‐year colleges that formed a statewide alliance. It details how the motivation for joining the alliance varied among the college leaders and describes the challenges the partners faced.
An alignment‐free methodology for modelling field‐based 3D‐structure activity relationships using inductive logic programming
Authors: Buttingsrud Bård , King Ross Donald , Alsberg Bjørn Kåre
Published: September 2007

Traditional 3D‐quantitative structure–activity relationship (QSAR)/structure–activity relationship (SAR) methodologies are sensitive to the quality of an alignment step which is required to make molecular structures comparable. Even though many methods have been proposed to solve this problem, they often result in a loss of model interpretability. The requirement of alignment is a restriction imposed by traditional regression methods due to their failure to represent relations between data objects directly. Inductive logic programming (ILP) is a class of machine‐learning methods able to describe relational data directly. We propose a new methodology which is aimed at using the richness in molecular interaction fields (MIFs) without being restricted by any alignment procedure. A set of MIFs is computed and further compressed by finding their minima corresponding to the sites of strongest interaction between a molecule and the applied test probe. ILP uses these minima to build easily interpretable rules about activity expressed as pharmacophore rules in the powerful language of first‐order logic. We use a set of previously published inhibitors of factor Xa of the benzamidine family to discuss the problems, requirements and advantages of the new methodology. Copyright © 2007 John Wiley & Sons, Ltd.
Sequential design of mixture experiments for the development of new products
Authors: Muteki Koji , MacGregor John F.
Published: September 2007

This paper presents a new sequential approach to mixture DOE that simultaneously selects new materials and ratios in which to combine them with the objective of achieving a set of specified final product properties. In each sequentially designed experiment the approach selects new materials and formulation ratios through an optimization based on mixture‐property partial least square (PLS) models that account for similarities among the properties of different materials (Muteki et al. 1, 2). The approach is useful for the case where one has existing experiments some of which may not be too far from those required for the desired new product. The sequential DOE methodo logy is demonstrated on an industrial polymer blending problem. Copyright © 2007 John Wiley & Sons, Ltd.
Identification of genes involved in radiation‐induced G1 arrest
Authors: Musumarra Giuseppe , Trovato‐Salinaro Angela , Scirè Salvatore , Foti Anna , Barresi Vincenza , Fortuna Cosimo Gianluca , Strazzulla Giovanni , Condorelli Daniele Filippo
Published: September 2007

The advent of microarray gene expression technology permits the simultaneous analysis of the levels of expression of thousands of genes and provides large dataset requiring multivariate analysis tools. Multiple genetic factors may modulate the occurrence and magnitude of the arrest in the G1 phase of the cell cycle following exposure to ionizing radiation in human tumour cell lines. The ability to G1 arrest after exposure to gamma rays and the global gene expression profile, evaluated by cDNA microarray technology, have been reported for the National Cancer Institute (NCI) 60 tumour cell lines panel. The sensitivity of the tumour cell lines to radiations represents an activity fingerprinting that can be correlated by partial least squares (PLS) to the transcriptional profiles of the same cell lines. VIP values obtained by the PLS method are able to detect transcripts relevant to the radiation‐induced G1 arrest. High VIP values were obtained for the basal levels of transcripts such as p21/Waf1/Cip1 and MDM2, that are well known for their roles in G1 arrest after irradiation. Novel functional relationships suggested by high VIP values can be investigated experimentally. As an example, in the present study, we report that the transcript for the FLJ11046 protein is induced dose‐dependently by gamma‐irradiation in a cell line with mutated p53, but not in cell lines with wild‐type p53. Moreover specific silencing of FLJ11046 transcript by RNA interference technology results in a block of cell growth. Copyright © 2007 John Wiley & Sons, Ltd.
Ligand‐Activated Lithium‐Mediated Zincation of N‐Phenylpyrrole
Authors: Seggio Anne , Lannou Marie‐Isabelle , Chevallier Floris , Nobuto Daisuke , Uchiyama Masanobu , Golhen Stéphane , Roisnel Thierry , Mongin Florence
Published: September 2007

Metalation of N‐phenylpyrrole by using an in situ mixture of ZnCl2⋅TMEDA (0.5 equiv; TMEDA=N,N,N′,N′‐tetramethylethylenediamine) and LiTMP (1.5 equiv; TMP=2,2,6,6‐tetramethylpiperidino) was optimized. The reaction carried out at room temperature in THF resulted in incomplete metalation (56 % conversion) and selectivity (mixture of 2‐iodo and 2,2′‐diiodo derivatives in an 86:14 ratio after trapping with iodine). By using diethyl ether (DEE), toluene, or hexane instead of THF, low conversions of 17, 38, or 23 % were observed, respectively, but the formation of the diiodide was avoided. When hexane was used as solvent, strong lithium‐complexing ligands such as [12]crown‐4 and N,N′‐dimethylpropylideneurea (DMPU) inhibited the reaction whereas more (hemi)labile ligands (TMEDA>THF≈DME) favored it. This result shows that a temporary accessibility of lithium to interact with the rest of the base and/or the substrate is a prerequisite for an efficient metalation. A 75 % yield of 2‐iodo‐N‐phenylpyrrole was obtained after reaction with the base in the presence of five equivalents of TMEDA for two hours at room temperature, and subsequent trapping with iodine. We were able to successfully replace the spare TMP with a less expensive butyl group.
Non‐Cytotoxic, Bifunctional EuIII and TbIII Luminescent Macrocyclic Complexes for Luminescence Resonant Energy‐Transfer Experiments
Authors: Ferrand Anne‐Claire , Imbert Daniel , Chauvin Anne‐Sophie , Vandevyver Caroline D. B. , Bünzli Jean‐Claude G.
Published: September 2007

A new macrocyclic ligand, L3, has been synthesised, based on the cyclen framework grafted with three phenacyl light‐harvesting groups and a C5‐alkyl chain bearing a carboxylic acid function as a potential linker for biological material. Acidity constants are determined by spectrophotometric titrations, as well as conditional stability constants for the resulting 1:1 complexes with trivalent lanthanide ions. The complexes have stabilities comparable to 1,4,7,10‐tetrakis(carbamoylmethyl)‐1,4,7,10‐tetraazacyclododecane (dtma) complexes, with pLn≈12–13. Photophysical properties of the ligand and of the EuL3 and TbL3 complexes have been determined for both microcrystalline samples and solutions in water and acetonitrile. They point to the metal ion being present in an environment with axial symmetry derived from the C4 point group. The hydration number determined for TbL3 decreases with increasing pH value and becomes fractional at pH 7.5, which points to an equilibrium between two differently solvated species and probably to the participation of the deprotonated carboxylic acid chain in the complexation. The quantum yields in water (1.9 % for EuIII, 3.4 % for TbIII) are smaller than those for complexes with the symmetrically substituted parent macrocycle, but efficient luminescence resonant energy transfer (LRET) was observed when Cy5 dye was added to the solutions. Finally, the influence of the TbL3 complex on cell viability is tested on both malignant (5D10 mouse hybridoma, Jurkat human T leukaemia, MCF‐7 human breast carcinoma) and non‐malignant (Hacat human keratinocyte) cell lines. Cell viability after 24 h incubation at 37 °C with 500 μM TbL3 was >90 % for all cell lines, except Jurkat (>70 %). All of these properties make LnL3 complexes interesting potential probes for bioanalyses.
Caldesmon is necessary for maintaining the actin and intermediate filaments in cultured bladder smooth muscle cells
Authors: Deng Maoxian , Mohanan Sunish , Polyak Erzsebet , Chacko Samuel
Published: September 2007

Caldesmon (CaD), a component of microfilaments in all cells and thin filaments in smooth muscle cells, is known to bind to actin, tropomyosin, calmodulin, and myosin and to inhibit actin‐activated ATP hydrolysis by smooth muscle myosin. Thus, it is believed to regulate smooth muscle contraction, cell motility and the cytoskeletal structure. Using bladder smooth muscle cell cultures and RNA interference (RNAi) technique, we show that the organization of actin into microfilaments in the cytoskeleton is diminished by siRNA‐mediated CaD silencing. CaD silencing significantly decreased the amount of polymerized actin (F‐actin), but the expression of actin was not altered. Additionally, we find that CaD is associated with 10 nm intermediate‐sized filaments (IF) and in vitro binding assay reveals that it binds to vimentin and desmin proteins. Assembly of vimentin and desmin into IF is also affected by CaD silencing, although their expression is not significantly altered when CaD is silenced. Electronmicroscopic analyses of the siRNA‐treated cells showed the presence of myosin filaments and a few surrounding actin filaments, but the distribution of microfilament bundles was sparse. Interestingly, the decrease in CaD expression had no effect on tubulin expression and distribution of microtubules in these cells. These results demonstrate that CaD is necessary for the maintenance of actin microfilaments and intermediate‐sized filaments in the cytoskeletal structure. This finding raises the possibility that the cytoskeletal structure in smooth muscle is affected when CaD expression is altered, as in smooth muscle de‐differentiation and hypertrophy seen in certain pathological conditions. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
Movement of stress fibers away from focal adhesions identifies focal adhesions as sites of stress fiber assembly in stationary cells
Authors: Endlich Nicole , Otey Carol A. , Kriz Wilhelm , Endlich Karlhans
Published: September 2007

Force generated in contractile actin filament bundles (stress fibers—SFs) is transmitted to the extracellular matrix (ECM) via linker proteins and transmembrane integrins at focal adhesions (FAs). Though it has long been known that actin is rapidly exchanged in FAs, the connection between SFs and FAs has not been studied in detail. We introduced fiduciary marks on SFs by expressing GFP‐palladin or GFP‐α‐actinin‐1, which are both FA and dense body proteins, and by pattern bleaching of GFP‐actin. Following fiduciary marks on SFs over time by time‐lapse fluorescence microscopy, we detected assembly of SFs at FAs in stationary cells resulting in movement of SFs away from FAs with a velocity of 0.2–0.4 μm/min. Visualization of FAs in GFP‐palladin/DsRed‐paxillin double transfected cells showed that SF elongation was not accompanied by a change in FA length. SF elongation at FAs depended on actin polymerization and force as demonstrated by inhibitors of actin polymerization (cytochalasin D, jasplakinolide) and inhibitors of myosin‐dependent contraction (blebbistatin, Y‐27632), respectively. Our finding of SF assembly at FAs has important implications for SF formation, force transmission, and tension distribution within the actin cytoskeletal network of stationary cells. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
Challenges and recommendations for advancing the state‐of‐the‐science of quality of life assessment in symptom management trials
Authors: Buchanan David R. , O'Mara Ann M. , Kelaghan Joseph W. , Sgambati Maria , McCaskill‐Stevens Worta , Minasian Lori
Published: September 2007

Major findings are presented from a workshop on Quality of Life Assessment in Cancer Symptom Management Trials, sponsored by the National Cancer Institute. Data‐driven research reports focused on 3 topics, 1) the rationale and utility of health‐related quality of life (HRQOL) assessment, 2) conceptual models, and 3) measurement and design issues. Recommendations for including HRQOL assessment cited the potential value of: capturing additional treatment effects (eg, fatigue + depression); describing the patient experience; predicting patient prognosis; identifying potential adverse effects; observing interactions among symptoms; calculating quality adjusted survival and cost‐effectiveness; and generating new hypotheses. Recommendations for developing more fully developed conceptual models focused on maintaining clear distinctions among symptoms, function, summary measures of HRQOL, and global HRQOL assessments; identifying symptom clusters; pursuing hypotheses about whether clustering is better explained as symptom‐related or as patient‐related (genetic predispositions); and gaining a better understanding of the dynamic and reciprocal influences of symptoms on each other. With respect to measurement and design issues, because different HRQOL measures cover different domains with various degrees of sensitivity, there is a need to select measures that are carefully tailored to the study's hypotheses. Finally, there is a growing appreciation that trials must be powered to test for effects on secondary endpoints. Cancer 2007. Published 2007 by the American Cancer Society.
Analysis of risk factors for distant metastases in squamous cell carcinoma of the oral cavity
Authors: Liao Chun‐Ta , Wang Hung‐Ming , Chang Joseph Tung‐Chieh , Ng Shu‐Hang , Hsueh Chuen , Lee Li‐Yu , Lin Chih‐Hung , Chen I‐How , Huang Shiang‐Fu , Yen Tzu‐Chen
Published: September 2007

BACKGROUND.

The number of patients with oral cavity squamous cell carcinoma (OSCC) is increasing. Because the characteristics of patients with OSCC who develop distant metastases (DM) remain uncertain, the authors analyzed potential risk factors.

METHODS.

For this report, the authors retrospectively reviewed data from 889 consecutive patients with OSCC who underwent radical surgery from January 1996 to November 2004. Patients were divided into 2 groups according to whether they had either achieved locoregional control (Group A; n = 678 patients) or developed a locoregional recurrence (Group B; n = 211 patients). Cox proportional‐hazards models were used to identify independent predictors of the 5‐year DM rate.

RESULTS.

In the entire study cohort, the 5‐year DM rate was 9.6% (6.6% for Group A and 21.4% for Group B). In Group A, the number of positive lymph nodes (≥5; P = .009) and the presence of extracapsular spread (ECS) (P < .001) were independent risk factors for DM. In Group B, the presence of ECS (P = .008), poor differentiation (P = .040), pathological stage ≥III (P = .036), and the presence of neck recurrence (P = .001) were independent prognosticators.

CONCLUSIONS.

The current results indicated that different risk factor categories according to locoregional control may be used to facilitate the selection of appropriate management for patients with OSCC after they undergo radical surgery. Cancer 2007. © 2007 American Cancer Society.
Practical time‐gated luminescence flow cytometry. I: Concepts
Authors: Jin Dayong , Connally Russell , Piper James
Published: September 2007

The method of time‐gated detection of long‐lifetime (1–2,000 μs) luminescence‐labeled microorganisms following rapid excitation pulses has proved highly efficient in suppressing nontarget autofluorescence (<0.1 μs), scatterings, and other prompt stray light (Hemmila and Mukkala, Crit Rev Clin Lab Sci 2001;38:441–519). The application of such techniques to flow cytometry is highly attractive but there are significant challenges in implementing pulsed operation mode to rapid continuous flowing sample to achieve high cell analysis rates (Leif R, Vallarino L, Rare‐earth chelates as fluorescent markers in cell separation and analysis, In: Cell Separation Science and Technology, ACS Symposium Series 464, American Chemical Society, 1991, pp 41–58; Condrau et al., Cytometry 1994;16:187–194; Condrau et al., Cytometry 1994;16:195–205; Shapiro HM, Improving signals from labels: Amplification and other techniques, In: Practical Flow Cytometry, 4th ed., Wiley, New York, 2002, p 345). We present here practical approaches for achieving high cell analysis rates at 100% detection efficiency, using time‐gated luminescence (TGL) flow cytometry. In particular, we report that new‐generation UV LEDs are practical sources in TGL flow cytometry.

Spatial effects of long‐lived luminescence from the target fluorophore in a fast‐flowing sample stream have been investigated; excitation and detection requirements in TGL flow cytometry were theoretically analyzed; two practical approaches, a triggered model and a continuous flow‐section model, were considered as a function of flow speed, sizes and relative positions of the excitation/detection spots, label lifetime, excitation pulse duration/intensity, and detection duration. A particular configuration using LED excitation to detect europium dye‐labeled targets in such a system has been modeled in detail.

In the triggered model, TGL mode is confined to a low repetition rate (<1 kHz) and engaged only while a target particle is present in the excitation zone. In the flow‐section model, TGL mode is engaged continuously at high repetition rates to permit much higher cell arrival rates. The detection of 5.7‐μm europium calibration beads in a UV LED‐excited TGL flow cytometer has been shown to be feasible with a calculated signal‐to‐background ratio up to 11:1. © 2007 International Society for Analytical Cytology
Data transmission over analog TV broadcasting
Authors: Koukourlis Christos S.
Published: September 2007

The implementation of a contemporary method that enables the transmission of digital information at a rate of 2 Mbps over TV signal using the existing broadcasting infrastructure is described. Detailed information on the prototype hardware is given along with experimental results that prove the validity of the proposed method. Finally, a concept for including the method to the existing TV broadcasting network is proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Serial concatenation of Hermitian codes with ring‐TCM codes
Authors: Johnston Martin , Carrasco Rolando A.
Published: September 2007

Hermitian codes are a class of very long algebraic‐geometric (AG) codes constructed from Hermitian curves, which outperform Reed–Solomon codes defined over the same finite fields and with the same code rates, as recently demonstrated by the authors. However, since there are no soft‐decision decoding algorithms for AG codes in the literature, the performance of Hermitian codes is limited and their potential is yet to be realized. An alternative method for achieving more significant coding gains is presented in this paper by serially concatenating long Hermitian codes with ring‐trellis‐coded modulation codes over the ring of integers ℤ4 and evaluating their performance through simulation results on the AWGN and Rayleigh fading channels. The scheme achieves large coding gains over single Hermitian and Reed–Solomon codes with no increase in bandwidth use and a performance comparable with the well‐known capacity‐approaching codes. Copyright © 2007 John Wiley & Sons, Ltd.
Historical review of sample preparation for chromatographic bioanalysis: pros and cons
Authors: Chang Min S. , Ji Qin , Zhang Jun , El‐Shourbagy Tawakol A.
Published: September 2007

Sample preparation is a major task in a regulated bioanalytical laboratory. The sample preparation procedure significantly impacts assay throughput, data quality, analysis cost, and employee satisfaction. Therefore, selecting and optimizing an appropriate sample preparation method is essential for successful method development. Because of our recent expertise, this article is focused on sample preparation for high‐performance liquid chromatography with mass spectrometric detection. Liquid chromatography with mass spectrometric detection (LC‐MS) is the most common detection technique for small molecules used in regulated bioanalytical laboratories. The sample preparation technologies discussed are pre‐extraction and post‐extraction sample processing, protein precipitation (PPT), liquid–liquid extraction (LLE), offline solid‐phase extraction (SPE), and online solid‐phase extraction. Since all these techniques were in use for more than two decades, numerous applications and variations exist for each technique. We will not attempt to categorize each variation. Rather, the development history, a brief theoretical background, and selected references are presented. The strengths and the limitations of each method are discussed, including the throughput improvement potential. If available, illustrations from presentations at various meetings by our laboratory are used to clarify our opinion. Drug Dev Res 68:107–133, 2007. ©2007 Wiley‐Liss, Inc.
Methylphenidate treatment recovers stress‐induced elevated dendritic spine densities in the rodent dorsal anterior cingulate cortex
Authors: Zehle Stefanie , Bock Joerg , Jezierski Grzegorz , Gruss Michael , Braun Katharina
Published: September 2007

Exposing pups of the rodent species Octodon degus to periodic separation stress during the first three postnatal weeks leads to behavioral alterations, which include reduced attention towards an emotional stimulus and motoric hyperactivity. These behavioral changes, which are reminiscent of symptoms of attention deficit hyperactivity disorder (ADHD), are paralleled by synaptic changes in the dorsal anterior cingulate cortex (ACd), a limbic cortex region, which plays a key role in the modulation of attentional and executive functions. ADHD is typically treated with methylphenidate (MP), a drug acting on the dopaminergic system. However, the effect of chronic MP‐treatment on neuronal and synaptic maturation in the developing brain is unknown. Applying the Golgi‐Cox stainining technique, we tested in which way chronic MP‐treatment interferes with dendritic and synaptic development in the ACd and whether this treatment can restore the stress‐induced changes of neuronal connectivity. We found that chronic treatment with 1 mg/kg MP recovers stress‐induced changes of spine densities in the ACd. Furthermore, MP‐treatment resulted in increased dendritic length and complexity in both, stressed as well as unstressed control animals. These results indicate that synaptic reorganization as well as dendritic growth in the prefrontal cortex continue into prepuberty and are modulated by MP‐treatment. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Extrinsic regulation of T‐type Ca2+ channel expression in chick nodose ganglion neurons
Authors: Pachuau Judith , Martin‐Caraballo Miguel
Published: September 2007

Functional expression of T‐type Ca2+ channels is developmentally regulated in chick nodose neurons. In this study we have tested the hypothesis that extrinsic factors regulate the expression of T‐type Ca2+ channels in vitro. Voltage‐gated Ca2+ currents were measured using whole‐cell patch clamp recordings in E7 nodose neurons cultured under various conditions. Culture of E7 nodose neurons for 48 h with a heart extract induced the expression of T‐type Ca2+ channels without any significant effect on HVA currents. T‐type Ca2+ channel expression was not stimulated by survival promoting factors such as BDNF. The stimulatory effect of heart extract was mediated by a heat‐labile, trypsin‐sensitive factor. Various hematopoietic cytokines including CNTF and LIF mimic the stimulatory effect of heart extract on T‐type Ca2+ channel expression. The stimulatory effect of heart extract and CNTF requires at least 12 h continuous exposure to reach maximal expression and is not altered by culture of nodose neurons with the protein synthesis inhibitor anisomycin, suggesting that T‐type Ca2+ channel expression is regulated by a posttranslational mechanism. Disruption of the Golgi apparatus with brefeldin‐A inhibits the stimulatory effect of heart extract and CNTF suggesting that protein trafficking regulates the functional expression of T‐type Ca2+ channels. Heart extract‐ or CNTF‐evoked stimulation of T‐type Ca2+ channel expression is blocked by the Jak/STAT and MAP kinase blockers, AG490 and U0126, respectively. This study provides new insights into the electrical differentiation of placode‐derived sensory neurons and the role of extrinsic factors in regulating the functional expression of Ca2+ channels. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Nitric oxide release from a single cell affects filopodial motility on growth cones of neighboring neurons
Authors: Tornieri Karine , Rehder Vincent
Published: September 2007

Nitric oxide (NO), a gaseous messenger, has been reported to be involved in a variety of functions in the nervous system, ranging from neuronal pathfinding to learning and memory. We have shown previously that the application of NO via NO donors to growth cones of identified Helisoma buccal neurons B5 in vitro induces an increase in filopodial length, a decrease in filopodial number, and a slowing in neurite advance. It is unclear, however, whether NO released from a physiological source would affect growth cone dynamics. Here we used cell bodies of identified neurons known to express the NO synthesizing enzyme nitric oxide synthase (NOS) as a source of constitutive NO production and tested their effect on growth cones of other cells in a sender‐receiver paradigm. We showed that B5 cell bodies induced a rapid increase in filopodial length in NO‐responsive growth cones, and that this effect was blocked by the NOS inhibitor 7‐NI, suggesting that the effect was mediated by NO. Inhibition of soluble guanylyl cyclase (sGC) with ODQ blocked filopodial elongation induced by B5 somata, confirming that NO acted via sGC. We also demonstrate that the effect of NO was reversible and that a cell releasing NO can affect growth cones over a distance of at least 100 μm. Our results suggest that NO released from a physiological source can affect the motility of nearby growth cones and thus should be considered a signaling molecule with the potential to affect the outcome of neuronal pathfinding in vivo. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007
Transcription factor TEAD2 is involved in neural tube closure
Authors: Kaneko Kotaro J. , Kohn Matthew J. , Liu Chengyu , DePamphilis Melvin L.
Published: September 2007

TEAD2, one of the first transcription factors expressed at the beginning of mammalian development, appears to be required during neural development. For example, Tead2 expression is greatest in the dorsal neural crest where it appears to regulate expression of Pax3, a gene essential for brain development. Consistent with this hypothesis, we found that inactivation of the Tead2 gene in mice significantly increased the risk of exencephaly (a defect in neural tube closure). However, none of the embryos exhibited spina bifida, the major phenotype of Pax3 nullizygous embryos, and expression of Pax3 in E11.5 Tead2 nullizygous embryos was normal. Thus, Tead2 plays a role in neural tube closure that is independent of its putative role in Pax3 regulation. In addition, the risk of exencephaly was greatest with Tead2 nullizygous females, and could be suppressed either by folic acid or pifithrin‐α. These results reveal a maternal genetic contribution to neural tube closure, and suggest that Tead2‐deficient mice provide a model for anencephaly, a common human birth defect that can be prevented by folic acid. genesis 45:577–587, 2007. Published 2007 Wiley‐Liss, Inc.
Visual deficits in developmental dyslexia: relationships between non‐linguistic visual tasks and their contribution to components of reading
Authors: Jones Manon W. , Branigan Holly P. , Kelly M. Louise
Published: September 2007

Developmental dyslexia is often characterized by a visual deficit, but the nature of this impairment and how it relates to reading ability is disputed (Brain 2003; 126: 841–865). In order to investigate this issue, we compared groups of adults with and without dyslexia on the Ternus, visual‐search and symbols tasks. Dyslexic readers yielded more errors on the visual‐search and symbols tasks compared with non‐dyslexic readers. A positive correlation between visual‐search and symbols task performance suggests a common mechanism shared by these tasks. Performance on the visual‐search and symbols tasks also correlated with non‐word reading and rapid automatized naming measures, and visual search contributed independent variance to non‐word reading. The Ternus task did not discriminate reading groups nor contributed significant variance to reading measures. We consider how visual‐attention processes might underlie specific component reading measures. Copyright © 2007 John Wiley & Sons, Ltd.