bluuebunny/crossref_metadata_2025 huggingface dataset:
A Wheel‐Shaped Single‐Molecule Magnet of [MnII3MnIII4]: Quantum Tunneling of Magnetization under Static and Pulse Magnetic Fields
Authors: Koizumi Satoshi , Nihei Masayuki , Shiga Takuya , Nakano Motohiro , Nojiri Hiroyuki , Bircher Roland , Waldmann Oliver , Ochsenbein Stefan T. , Güdel Hans U. , Fernandez‐Alonso Felix , Oshio Hiroki
Published: August 2007

The reaction of N‐(2‐hydroxy‐5‐nitrobenzyl)iminodiethanol (=H3(5‐NO2‐hbide)) with Mn(OAc)2⋅ 4 H2O in methanol, followed by recrystallization from 1,2‐dichloroethane, yielded a wheel‐shaped single‐molecule magnet (SMM) of [MnII3MnIII4(5‐NO2‐hbide)6]⋅5 C2H4Cl2 (1). In 1, seven manganese ions are linked by six tri‐anionic ligands and form the wheel in which the two manganese ions on the rim and the one in the center are MnII and the other four manganese ions are MnIII ions. Powder magnetic susceptibility measurements showed a gradual increase with χmT values as the temperature was lowered, reaching a maximum value of 53.9 emu mol−1 K. Analyses of magnetic susceptibility data suggested a spin ground state of S=19/2. The zero‐field splitting parameters of D and ${B{{0\hfill \atop 4\hfill}}}$ were estimated to be −0.283(1) K and −1.64(1)×10−5 K, respectively, by high‐field EPR measurements (HF‐EPR). The anisotropic parameters agreed with those estimated from magnetization and inelastic neutron scattering experiments. AC magnetic susceptibility measurements showed frequency‐dependent in‐ and out‐of‐phase signals, characteristic data for an SMM, and an Arrhenius plot of the relaxation time gave a re‐orientation energy barrier (ΔE) of 18.1 K and a pre‐exponential factor of 1.63×10−7 s. Magnetization experiments on aligned single crystals below 0.7 K showed a stepped hysteresis loop, confirming the occurrence of quantum tunneling of the on magnetization (QTM). QTM was, on the other hand, suppressed by rapid sweeps of the magnetic field even at 0.5 K. The sweep‐rate dependence of the spin flips can be understood by considering the Landau–Zener–Stückelberg (LZS) model.
A Quantum Mechanically Guided View of Mg44Rh7
Authors: Berger Robert F. , Lee Stephen , Hoffmann Roald
Published: August 2007

We present a new geometric description of Mg44Rh7, a compound with 408 atoms in its cubic unit cell. Using both experimental site preferences and LDA‐DFT‐calibrated extended Hückel (eH) calculations as guides, we highlight the structural units within Mg44Rh7 that reflect the electron‐richness or electron‐poorness of each crystallographic site. The units that best account for these site preferences and electron populations are 34‐ and 25‐atom fragments of the Ti2Ni structure, rather than the variety of clusters often used to describe complicated intermetallic and ionic structures. These Ti2Ni pieces, located using a systematic search algorithm, fit together in a beautifully intricate network. An examination of this network reveals some surprising geometric features of Mg44Rh7, including a fractal‐like arrangement of similar atomic formations on different length scales, geometrically connected to an approximate fivefold symmetry.
Assessing credit quality from the equity market: can a structural approach forecast credit ratings?
Authors: Du Yu , Suo Wulin
Published: August 2007

We investigate the empirical performance of default probability prediction based on Merton's (1974) structural credit risk model. More specifically, we study if distance‐to‐default is a sufficient statistic for the equity market information concerning the credit quality of the debt‐issuing firm. We show that a simple reduced form model outperforms the Merton (1974) model for both in‐sample fitting and out‐of‐sample predictability for credit ratings, and that both can be greatly improved by including the firm's equity value as an additional variable. Moreover, the empirical performance of this hybrid model is very similar to that of the simple reduced form model. As a result, we conclude that distant‐to‐default alone does not adequately capture the firm's credit quality information from the equity market. Copyright © 2007 ASAC. Published by John Wiley & Sons, Ltd.
Genetic Heterogeneity of Left‐ventricular Noncompaction Cardiomyopathy
Authors: Moric‐Janiszewska Ewa , Markiewicz‐Łoskot Grazyna
Published: August 2007

Isolated noncompaction of the ventricular myocardium (INVM) sometimes referred to as spongy myocardium is a rare, congenital and also acquired cardiomyopathy. It appears to divide the presentation into neonatal, childhood and adult forms of which spongy myocardium and systolic dysfunction is the commonality. The disorder is characterized by a left ventricular hypertrophy with deep trabeculations, and with diminished systolic function, with or without associated left ventricular dilation. In half or more of the cases, the right ventricle is also affected. The sporadic type, however, in some patients, may be due to chromosomal abnormalities and the occurrence of familial incidence. Isolated noncompaction of the left ventricular myocardium in the majority of adult patients is an autosomal dominant disorder. The familial and X‐linked disorders have been described by various authors. We here describe the genetic background of this disorder: some of the most mutated genes that are responsible for the disease are (G4.5 (tafazzin gene): α‐dystrobrevin gene (DTNA); FKBP‐12 gene; lamin A/C gene; Cypher/ZASP (LIM, LDB3) gene); and some genotype‐phenotype correlations (Becker muscular dystrophy, Emery‐Dreifuss muscular dystrophy or Barth syndrome) based on the literature review. Copyright © 2007 Wiley Periodicals, Inc.
Characterization of progenitor domains in the developing mouse thalamus
Authors: Vue Tou Yia , Aaker Joshua , Taniguchi Aya , Kazemzadeh Christina , Skidmore Jennifer M. , Martin Donna M. , Martin James F. , Treier Mathias , Nakagawa Yasushi
Published: August 2007

To understand the molecular basis of the specification of thalamic nuclei, we analyzed the expression patterns of various transcription factors and defined progenitor cell populations in the embryonic mouse thalamus. We show that the basic helix‐loop‐helix (bHLH) transcription factor Olig3 is expressed in the entire thalamic ventricular zone and the zona limitans intrathalamica (ZLI). Next, we define two distinct progenitor domains within the thalamus, which we name pTH‐R and pTH‐C, located caudal to the ZLI. pTH‐R is immediately caudal to the ZLI and expresses Nkx2.2, Mash1, and Olig3. pTH‐C is caudal to pTH‐R and expresses Ngn1, Ngn2, and Olig3. Short‐term lineage analysis of Olig3‐, Mash1‐, Ngn1‐, and Ngn2‐expressing progenitor cells as well as tracing the Pitx2 cell lineage suggests that pTH‐C is the only major source of thalamic nuclei containing neurons that project to the cerebral cortex, whereas pTH‐R and ZLI are likely to produce distinct postmitotic populations outside of the cortex‐projecting part of the thalamus. To determine if pTH‐C is composed of subdomains, we characterized expression of the homeodomain protein Dbx1 and the bHLH protein Olig2. We show that Dbx1 is expressed in caudodorsal‐high to rostroventral‐low gradient within pTH‐C. Analysis of heterozygous Dbx1nlslacZ knockin mice demonstrated that Dbx1‐expressing progenitors preferentially give rise to caudodorsal thalamic nuclei. Olig2 is expressed in an opposite gradient within pTH‐C to that of Dbx1. These results establish the molecular heterogeneity within the progenitor cells of the thalamus, and suggest that such heterogeneity contributes to the specification of thalamic nuclei. J. Comp. Neurol. 505:73–91, 2007. © 2007 Wiley‐Liss, Inc.
Alterations in photoreceptor‐bipolar cell signaling following ischemia/reperfusion in the rat retina
Authors: Sun Daniel , Bui Bang V. , Vingrys Algis J. , Kalloniatis Michael
Published: August 2007

Studies of retinal ischemia/reperfusion indicate a disparity between the anatomical and functional results; while a large number of rod bipolar cells remain postischemia, there is a significant reduction in the amplitude of the scotopic b‐wave of the electroretinogram (ERG). We investigated the alterations in photoreceptor‐bipolar cell signaling following ischemia/reperfusion and suggest a mechanism for the decrease in b‐wave amplitude. A cation channel probe (agmatine, 1‐amino‐4‐guanidobutane, AGB) was used to assess cellular ion channel activity in neurochemically identified cells secondary to endogenous glutamate release or pharmacological manipulations. By applying the “neurochemical truth point” principle (Sun et al. [2007a] J Comp Neurol, this issue), we have been able to confirm the loss of specific subpopulations of neurons. ERG was used to assess gross retinal function, with parameters of the ERG model providing insight into changes in the phototransduction cascade and sensitivity of postreceptoral glutamate receptors. Following ischemia/reperfusion, rod bipolar cells maintained 2‐amino‐4‐phosphonobutyric acid‐responsive metabotropic glutamate receptors and displayed no change in sensitivity to flashes of light as assessed by ERG. Therefore, the loss in b‐wave amplitude is likely due to alterations in photoreceptoral glutamate release detected as a change in postsynaptic AGB permeation into rod bipolar cells. Bipolar cell to amacrine cell signaling was also altered. The robust AGB entry into cholinergic amacrine cells was virtually absent in retinas that had undergone ischemia/reperfusion but remained in the AII amacrine cells. Such results suggest a loss of glutamate receptors and/or a change in receptor subunit expression in subpopulations of inner retinal neurons. Although many cells retain their characteristic neurochemical labeling following ischemia/reperfusion, caution should be used when assuming cells participate in functional retinal circuits based solely on the persistence of neurochemical labeling. J. Comp. Neurol. 505:131–146, 2007. © 2007 Wiley‐Liss, Inc.
Hybrid Organic/Inorganic Supramolecular Conductors D2[Au(CN)4] [D = Diiodo(ethylenedichalcogeno)tetrachalcogenofulvalene], Including a New Ambient Pressure Superconductor
Authors: Imakubo Tatsuro , Shirahata Takashi , Kibune Megumi , Yoshino Hiroko
Published: August 2007

Five diiodo(ethylenedichalcogeno)tetrachalcogenofulvalenes, DIEDSS {2‐(5,6‐dihydro[1,3]diselenolo[4,5‐b][1,4]diselenin‐2‐ylidene)‐4,5‐diiodo‐1,3‐dithiole}, DIET‐STF {2‐(4,5‐diiodo‐1,3‐diselenol‐2‐ylidene)‐5,6‐dihydro[1,3]dithiolo[4,5‐b][1,4]dithiine}, DIEDS‐STF {2‐(4,5‐diiodo‐1,3‐diselenol‐2‐ylidene)‐5,6‐dihydro[1,4]diselenino[2,3‐d][1,3]dithiole}, DIETSe {2‐(4,5‐diiodo‐1,3‐diselenol‐2‐ylidene)‐5,6‐dihydro[1,3]diselenolo[4,5‐b][1,4]dithiine}, and DIEDSSe {2‐(4,5‐diiodo‐1,3‐diselenol‐2‐ylidene)‐5,6‐dihydro[1,3]diselenolo[4,5‐b][1,4]diselenine},have been synthesized without the use of the highly toxic reagent CSe2, and their Au(CN)4 salts have been prepared by electrochemical oxidation. Characteristic I···N iodine bonds are constructed in all crystals, and their packing motifs are classified into two groups by the difference in the space group symmetry. The salt of DIEDSS crystallizes in the monoclinic C2/c space group and a novel helical supramolecular architecture is constructed by the strong and directional I···N iodine bond. On the other hand, the rest of the four salts crystallize in the triclinic P$\bar {1}$ space group and their donor packing motifs belong to the so‐called β‐type. Conducting properties of the β‐type salts strongly depend on the number and positions of the selenium atoms on the donor molecule. The salts based on the diselenadithiafulvalene (DSDTF) derivatives, DIET‐STF and DIEDS‐STF, show metal–semiconductor transition and the salt of fully selenated π‐donor DIEDSSe shows stable metallic behavior down to 1.6 K. On the other hand, (DIETSe)2[Au(CN)4] is semimetallic down to low temperature and the superconducting transition occurs at around 2 K (onset).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Unexpected Outcome in the Reaction of Triazolinedione with Carbon Nanotubes
Authors: Ménard‐Moyon Cécilia , Gross Marius , Bernard Maxime , Turek Philippe , Doris Eric , Mioskowski Charles
Published: August 2007

The reactivity of triazolinedione (TAD) was investigated in the Diels–Alder reaction with carbon nanotubes. However, an unexpected conversion of TAD into its deaza dimer was observed. ESR spectroscopy suggested that the process was initiated by electron transfer from the nanotubes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Use the environmental knowledge and assessment tool to assist with environmental management
Authors: Boguski Terrie , Erickson L.E. , Fredkin Jay , Green Ryan , Jamka Leslie , Norris Greg , Vera Lynette , Whiteley Clinton
Published: August 2007

Designed and built by the National Environmental Evaluation and Remediation Consortium, the Environmental Knowledge and Assessment Tool (EKAT™) at www.ekat‐tool.com is a web‐based project management and decision‐support tool to identify, research, and evaluate environmental and pollution prevention options, and safety‐related issues for materials used in products and systems.

The original concept of EKAT was to help Marine Corps Systems Command integrate environmental requirements into systems acquisition programs. The tool can also benefit federal and state agencies, communities, and businesses.

EKAT contains information on technical and regulatory requirements and serves as a resource center with links to references, tools, and databases to assist in research efforts and minimize unintentional safety and environmental effects associated with product development or use. Features include project management and organizational capability, collaboration within project teams or the EKAT community, and communication through threaded discussions.

EKAT serves as a preliminary environmental screening tool for regulatory requirements and issues of concern. The user may enter or download lists of chemicals that she or he may have obtained from material safety data sheets for products typically used in activities and operations; these chemicals can then be screened against 14 lists of federally regulated chemicals. Some of the federal lists for which the user's entered chemicals are screened against include the Clean Air Act, the Clean Water Act, the Resource Conservation and Recovery Act, the Emergency Planning and Community Right‐to‐Know Act, various lists of carcinogenic substances, and more. Users may also get help estimating emissions from equipment and manufacturing processes, or review information resource documents and research guides, which provide additional environmental information and resources in a user‐friendly format.

All regulatory information, for environmental, health, and safety issues found within EKAT, is based on United States federal laws and regulations, to which links can be found throughout. Links to sources of additional information, other than U.S. governmental web sites or resources, may also be found in EKAT. © 2007 American Institute of Chemical Engineers Environ Prog, 2007
Simple efficient algorithm (SEA) for shallow flows with shock wave on dry and irregular beds
Authors: Zia Alireza , Banihashemi Mohamad Ali
Published: August 2007

An explicit Godunov‐type solution algorithm called SEA (simple efficient algorithm) has been introduced for the shallow water equations. The algorithm is based on finite volume conservative discretisation method. It can deal with wet/dry and irregular beds. Second‐order accuracy, in both time and space, is achieved using prediction and correction steps. A very simple and efficient flux limiting technique is used to equip the algorithm with total variation dimensioning property for shock capturing purposes. In order to make sure about the balance between the flux gradient and the bed slope, treatment of the source term has been done using a new procedure inspired mainly by the physical rather than mathematical consideration. SEA has been applied to one‐dimensional problems, although it can equally be applied to multi‐dimensional problems. In order to assess the
capability of proposed algorithm in dealing with practical applications, several test cases have been examined. Copyright © 2007 John Wiley & Sons, Ltd.
Preliminary soil micromorphology studies of landscape and occupation history at Tabon Cave, Palawan, Philippines
Authors: Lewis Helen
Published: August 2007

Preliminary soil micromorphology study of cultural sediments at Tabon Cave, Philippines, supports interpretations of sporadic occupation in the Paleolithic. The presence in some deposits of authigenic minerals potentially related to altered cultural materials, such as ash, needs further investigation. Later in the sequence there is a marked change in local depositional processes, with the onset of significant quartz sand deposition in layers dating from the Middle to Late Holocene. This could relate to beach development in the area. Future sedimentological study and dating would confirm this interpretation, which suggests that in appropriate settings, stratified cave sediments could be useful for the study of regional sea level rise. © 2007 Wiley Periodicals, Inc.
Multidisciplinary investigations at Stalag Luft III allied prisoner‐of‐war camp: The site of the 1944 “great escape,” Zagan, Western Poland
Authors: Pringle J.K. , Doyle P. , Babits L.E.
Published: August 2007

Stalag Luft III, situated in Zagan, Poland (formerly eastern Germany), was the site of a World War II Allied aviator prisoner of war (POW) camp famous for repeat escape attempts—notably the mass escape of 76 POWs in March 1944, shown in the 1963 film “The Great Escape.” The site has had little attention to date because it was within restricted military training grounds until 1992. This paper reports on attempts to locate the undiscovered “Dick” escape tunnel (the “Tom” and “Harry” tunnels from the same escape attempt were discovered and destroyed by camp authorities). Geological and geophysical surveys located hut 122, which contained the “Dick” entrance shaft. Subsequent archaeological investigations included surface artifact collection and inspection of the rubble‐filled, tunnel entrance shaft. Excavations to a depth of 10 m through yellow glacio‐fluvial sand resulted in the discovery of the refilled “Dick” tunnel with intact bed‐board shoring and ventilation system. Our investigation provides valuable insights into POW escape efforts. © 2007 Wiley Periodicals, Inc.
p38 mitogen‐activated protein kinase is required for central nervous system myelination
Authors: Fragoso Gabriela , Haines Jeffery D. , Roberston Janice , Pedraza Liliana , Mushynski Walter E. , Almazan Guillermina
Published: August 2007

The p38 MAPKs are a family of kinases that regulate a number of cellular functions including cell migration, proliferation, and differentiation. Here, we report that p38 regulates oligodendrocyte differentiation. Inhibition of p38 with PD169316 and SB203580 prevented accumulation of protein and mRNA of cell‐stage specific markers characteristic of differentiated oligodendrocytes, including myelin basic protein, myelin‐associated glycoprotein, and the glycosphingolipids, galactosylceramide and sulfatide. In addition, the cell cycle regulator p27kip1 and the transcription factor Sox10 were also significantly reduced. Most significantly, p38 inhibitors completely and irreversibly blocked myelination of dorsal root ganglion neurons by oligodendrocytes and prevented the axolemmal organization of the axo‐glial adhesion molecule Caspr. Our results suggest a role(s) for this kinase in key regulatory steps in the maturation of OLGs and initiation of myelination. © 2007 Wiley‐Liss, Inc.
Basigin/EMMPRIN/CD147 mediates neuron‐glia interactions in the optic lamina of Drosophila
Authors: Curtin Kathryn D. , Wyman Robert J. , Meinertzhagen Ian A.
Published: August 2007

Basigin, an IgG family glycoprotein found on the surface of human metastatic tumors, stimulates fibroblasts to secrete matrix metalloproteases (MMPs) that remodel the extracellular matrix, and is thus also known as Extracellular Matrix MetalloPRotease Inducer (EMMPRIN). Using Drosophila we previously identified novel roles for basigin. Specifically, photoreceptors of flies with basigin eyes show misplaced nuclei, rough ER and mitochondria, and swollen axon terminals, suggesting cytoskeletal disruptions. Here we demonstrate that basigin is required for normal neuron‐glia interactions in the Drosophila visual system. Flies with basigin mutant photoreceptors have misplaced epithelial glial cells within the first optic neuropile, or lamina. In addition, epithelial glia insert finger‐like projections—capitate projections (CPs)—sites of vesicle endocytosis and possibly neurotransmitter recycling. When basigin is missing from photoreceptors terminals, CP formation between glia and photoreceptor terminals is disrupted. Visual system function is also altered in flies with basigin mutant eyes. While photoreceptors depolarize normally to light, synaptic transmission is greatly diminished, consistent with a defect in neurotransmitter release. Basigin expression in photoreceptor neurons is required for normal structure and placement of glia cells. © 2007 Wiley‐Liss, Inc.
Bed‐sharing practices of initially breastfed infants in the first 6 months of life
Authors: Ball Helen L.
Published: August 2007

This paper explores the manner in which bed‐sharing is practised by breastfeeding infants in the UK, and examines how alternate definitions and interpretations of breastfeeding and bed‐sharing can lead to confusion in understanding what bed‐sharing entails. Longitudinal studies on parent–infant bed‐sharing practices are scarce, but are vital to our understanding of normative bed‐sharing behaviour. We present data from a longitudinal study of sleeping and feeding practices in England involving 97 initially breastfed infants from birth to 6 months of age whose behaviour was monitored weekly for a 6‐month period. Results demonstrate that bed‐sharing practices covary with breastfeeding practices, and that a single model of bed‐sharing behaviour does not adequately reflect the experience of all infants. Our findings have ramifications for the way in which case–control studies attempt to ‘measure’ bed‐sharing, and our understanding and interpretation of bed‐sharing risk factors. Copyright © 2007 John Wiley & Sons, Ltd.
The ontogeny of diurnal rhythmicity in bed‐sharing and solitary‐sleeping infants: a preliminary report
Authors: Burnham Melissa M.
Published: August 2007

The purpose of the current study was to investigate the development of sleep–wake and melatonin diurnal rhythms over the first 3 months of life, and the potential effect of bed‐sharing on their development. It was hypothesized that increased maternal contact through bed‐sharing would affect the development of rhythms in human infants. Ten solitary‐sleeping and 8 bed‐sharing infants' sleep–wake patterns and melatonin secretion were examined for 72 h at 1 and 3 months of age in their homes. Infants wore actigraphs on their ankles to study sleep–wake patterns. 6‐Sulphatoxymelatonin was obtained through urine extracted from each diaper used over the 72‐h study period. No significant differences were apparent in the timing of appearance or magnitude of sleep–wake or melatonin rhythms between bed‐sharing and solitary‐sleeping infants. Sleep–wake results were in the expected direction, with bed‐sharing infants displaying more robust rhythms. A large degree of individual variability was evident in both rhythms, especially at 1 month. Three infants' parents regularly used a bright light source at night for feedings and diaper changes; the rhythms of these infants were less robust than the rest of the sample. Trends were mostly in the hypothesized direction and deserve attempts at replication with a larger sample. Copyright © 2007 John Wiley & Sons, Ltd.
Co‐sleeping during infancy and early childhood: key findings and future directions
Authors: Goldberg Wendy A. , Keller Meret A.
Published: August 2007

Emergent themes from this special issue on parent–child co‐sleeping are featured in this concluding article. Each of the pieces in this collection addressed one or more of the following themes: methodologies for studying parent–infant co‐sleeping, physical and social characteristics of the child's sleep environment, associations between sleep location and breastfeeding, infant and child maturational issues, parental attitudes and values about sleep arrangements, special needs populations, maternal employment, sleep problems, sleep transitions, and future directions for research and policy. Together, the contributions define a context for weighing the benefits and disadvantages of family sleep arrangements during infancy and early childhood. Copyright © 2007 John Wiley & Sons, Ltd.
Parent–infant co‐sleeping: why the interest and concern?
Authors: Goldberg Wendy A. , Keller Meret A.
Published: August 2007

The practice of parents and their young children co‐sleeping is a topic of ongoing controversy and debate. Both physical and psychosocial risks and benefits have been attached to this practice. In this introduction to the special issue, we present the prevailing views about early sleep arrangements. We then discuss the organization of the special issue and highlight the contributions of each article. Together, this collection of original articles comprises a body of research that advances our understanding of co‐sleeping in the context of social and physical environments. Copyright © 2007 John Wiley & Sons, Ltd.
Parental perceptions of sleep problems among co‐sleeping and solitary sleeping children
Authors: Ramos Kathleen Dyer , Youngclarke Davin , Anderson Jane E.
Published: August 2007

To explore whether parental report of frequency of problematic sleep behaviours overestimates the subjective experience of sleep problems among co‐sleepers, and whether classification as reactive or intentional co‐sleeping is related to parental judgments about children's sleep, 139 parents of young children were recruited from urban paediatric offices. The Child Sleep Behaviour Survey asked about potentially problematic sleep behaviours, and yielded a simple frequency score (frequency of all items) and a weighted frequency score (only behaviours considered problematic by the parent). Parents described sleeping arrangements and demographic characteristics. Simple frequency of behaviours was higher among co‐sleepers than among solitary sleepers. Weighted frequencies were lower in all groups, but highest among reactive co‐sleepers. Parents of intentional co‐sleepers notice children's sleep behaviours that they do not consider problematic. Copyright © 2007 John Wiley & Sons, Ltd.
Reusable, reversibly sealable parylene membranes for cell and protein patterning
Authors: Wright Dylan , Rajalingam Bimalraj , Karp Jeffrey M. , Selvarasah Selvapraba , Ling Yibo , Yeh Judy , Langer Robert , Dokmeci Mehmet R. , Khademhosseini Ali
Published: August 2007

The patterned deposition of cells and biomolecules on surfaces is a potentially useful tool for in vitro diagnostics, high‐throughput screening, and tissue engineering. Here, we describe an inexpensive and potentially widely applicable micropatterning technique that uses reversible sealing of microfabricated parylene‐C stencils on surfaces to enable surface patterning. Using these stencils it is possible to generate micropatterns and copatterns of proteins and cells, including NIH‐3T3 fibroblasts, hepatocytes and embryonic stem cells. After patterning, the stencils can be removed from the surface, plasma treated to remove adsorbed proteins, and reused. A variety of hydrophobic surfaces including PDMS, polystyrene and acrylated glass were patterned using this approach. Furthermore, we demonstrated the reusability and mechanical integrity of the parylene membrane for at least 10 consecutive patterning processes. These parylene‐C stencils are potentially scalable commercially and easily accessible for many biological and biomedical applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Biomechanical properties of carbodiimide crosslinked collagen: Influence of the formation of ester crosslinks
Authors: Everaerts Frank , Torrianni Mark , Hendriks Marc , Feijen Jan
Published: August 2007

There is a growing interest in the use of collagen matrices for tissue engineering. To prevent rapid degradation and to improve their mechanical properties, collagen matrices have been modified using different crosslinking agents. Among the different agents used, water soluble carbodiimides (such as N′‐(3‐dimethylaminopropyl)‐N‐ethylcarbodiimide, EDC) in combination with N‐hydroxysuccinimide (NHS) are attractive systems, because no additional chemical entities are incorporated in the matrix. EDC/NHS crosslinking leads to amide bond formation between activated carboxyl groups and amine groups. Recently, we proposed that in addition to amide bond formation, ester links are also formed between activated carboxyl groups and hydroxyl groups. This was based on observations we made after development of a new method to quantify concentrations of carboxyl groups of collagen materials before and after crosslinking. The current study is directed to the influence of ester bond crosslinks formed after crosslinking of collagen with EDC/NHS on its physical–chemical and biomechanical properties. Reconstituted dermal bovine collagen patches (RDBC) were used as model material and were crosslinked with EDC/NHS. In one RDBC group, collagen amine groups were blocked with propionaldehyde prior to crosslinking, while in the other group unprocessed RDBC was crosslinked without additional matrix modifications. It was shown that after activation of collagen carboxyl groups with EDC and NHS, amide crosslinks as well as ester crosslinks with collagen hydroxyl groups were formed. It was furthermore demonstrated that the ester crosslinks of EDC/NHS‐crosslinked RDBC could be removed by mild hydrolysis affording collagen matrices with improved mechanical properties. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Effect of Salvia miltiorrhiza extract on bone formation
Authors: Wong R. W. K. , Rabie A. B. M.
Published: August 2007

Salvia miltiorrhiza (SM) is a Chinese medicine used for treatment of cardiac diseases through improving blood circulation. Our laboratory compared the amount of new bone formed in collagen matrix with SM extract to that formed in the collagen matrix alone. Eighteen bone defects, 5 mm × 10 mm were created in the parietal bone of nine New Zealand White rabbits. In the experimental group, six defects were grafted with collagen matrix with SM extract. In the control groups, six defects were grafted with collagen matrix alone (positive control) and six were left empty (negative control). Animals were killed on day 14 and the defects were dissected and prepared for histological assessment. Serial sections were cut across each defect. Quantitative analysis of new bone formation was made on 100 sections (50 sections for each group of SM and positive control) using image analysis. A total of 478% more new bone was present in defects grafted with SM extract in collagen matrix than those grafted with the collagen matrix alone. Very little new bone was formed in the passive control group. In conclusion, SM extract in collagen matrix has the effect of increasing new bone formation locally and can be used for bone grafting especially in cases with compromised vascular responses. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Vaccines to treat cancer‐an old approach whose time has arrived
Authors: Hellstrom Karl Erik , Hellstrom Ingegerd
Published: August 2007

There are extensive DNA changes in tumor cells and the genes of tumor cells continuously mutate at a high rate. While this can provide therapeutic targets, it makes it unlikely that an agent that is selective for a single target will work against all cells in a tumor. However, it may be possible to use tumor epitopes as sentinels to engage adaptive and innate immunological mechanisms and create a tumor destructive environment effective also against variant cells that have lost a given antigen or their ability to present it. We hypothesize that therapeutic tumor vaccines, in combination with the targeting, to tumors, of costimulatory molecules such as anti‐CD137scFv, or lymphokines such as GMCSF, will expand anti‐tumor responses for therapeutic benefit when used as an adjunct to surgery and chemotherapy. J. Cell. Biochem. 102: 291–300, 2007. © 2007 Wiley‐Liss, Inc.
TGF‐β signaling: A tale of two responses
Authors: Rahimi Rod A. , Leof Edward B.
Published: August 2007

Transforming growth factor‐β (TGF‐β) regulates a wide variety of cellular processes including cell growth, apoptosis, differentiation, migration, and extracellular matrix production among others. The canonical signaling pathway induced by the TGF‐β receptor complex involves the phosphorylation of Smad proteins which upon activation accumulate in the nucleus and regulate transcription. Interestingly, the cellular response to TGF‐β can be extremely variable depending on the cell type and stimulation context. TGF‐β causes epithelial cells to undergo growth arrest and apoptosis, responses which are critical to suppressing carcinogenesis, whereas it can also induce epithelial‐mesenchymal transition and mediate fibroblast activation, responses implicated in promoting carcinogenesis and fibrotic diseases. However, TGF‐β induces all these responses via the same receptor complex and Smad proteins. To address this apparent paradox, during the last few years a number of additional signaling pathways have been identified which potentially regulate the different cellular responses to TGF‐β. The identification of these signaling pathways has shed light onto the mechanisms whereby Smad and non‐Smad pathways collaborate to induce a particular cellular phenotype. In this article, we review TGF‐β signaling in epithelial cells and fibroblasts with a focus on understanding the mechanisms of TGF‐β versatility. J. Cell. Biochem. 102: 593–608, 2007. © 2007 Wiley‐Liss, Inc.
A potent replicative delta‐24 adenoviral vector driven by the promoter of human papillomavirus 16 that is highly selective for associated neoplasms
Authors: Delgado‐Enciso Iván , Cervantes‐García Daniel , Martínez‐Dávila Irma A. , Ortiz‐López Rocío , Alemany‐Bonastre Ramón , Silva‐Platas Christian I. , Lugo‐Trampe Ángel , Barrera‐Saldaña Hugo A. , Galván‐Salazar Héctor R. , Coronel‐Tene Christian G. , Sánchez‐Santillán Carlos F. , Rojas‐Martínez Augusto
Published: August 2007

Background

Several human epithelial neoplasms are associated with high‐risk strains of human papillomavirus (HPV) such as cervical, anorectal, and other carcinomas. For some tumor types the current therapeutic tools are only palliative. Conditionally replicative adenoviruses (CRAds) are promising antineoplastic agents, which also can trigger confined antitumor effects.

Methods

We constructed a series of CRAds driven by the upstream regulatory promoter region (URR) of an Asian‐American variant of HPV‐16, which contained different mutations at the E1A region (dl1015 and/or Δ24) and wild‐type. All vectors were tested in vitro for viral replication and cytotoxicity. Viral DNA replication and E1A expression were also assessed by quantitative PCR. Finally, we confirmed the antitumoral efficacy of this vector in injected and non‐injected xenotransplanted cervical tumors in a murine model for tumor regression and survival studies.

Results

A vector denominated Ad‐URR/E1AΔ24 displayed a potent cytopathic effect associated with high selectivity for HPV+ cell lines. We found that the oncolytic effect of this CRAd was comparable to Ad‐wt or Ad‐Δ24, but this efficacy was significantly attenuated in HPV− cell lines, an effect that was contributed by the URR promoter. Ad‐URR/E1AΔ24 was very effective to control tumor growth, in both, injected and non‐injected tumors generated with two different HPV+ cell lines.

Conclusions

CRAd Ad‐URR/E1AΔ24 is a highly selective vector for HPV+ cell lines and tumors that preserves the oncolytic efficacy of Ad‐wt and Ad‐Δ24. Our preclinical data suggest that this vector may be useful and safe for the treatment of tumors induced by HPV, like cervical cancers. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling bioclimate by means of Fourier analysis of NOAA‐AVHRR NDVI time series in Western Argentina
Authors: Loyarte María M. González , Menenti Massimo , Diblasi Angela M.
Published: August 2007

This study assessed whether the relationship of climate with foliar phenology is sufficiently robust to use a measure of foliar phenology to interpolate climate statistics in areas where observations are sparse. The normalized difference vegetation index (NDVI) was used to represent vegetation activity. As a measure of foliar phenology, we used parameters obtained by modelling NDVI time series with a Fast Fourier Transform (FFT) applied to a 9‐year time series of monthly National Oceanographic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) NDVI global area coverage (GAC) images. The FFT decomposes the series into an average signal and to sinusoidal components. The selected FFT parameters were mean NDVI, and amplitude and phase for a 1‐year period. Our specific objective was to relate the ratio of precipitation, P, over potential evapotranspiration, ETP, to the FFT parameters in two complementary ways. The first was to use them as attributes in a numerical classification to obtain a map of foliar isophenology, and then associate these classes with bioclimatic types, thus generating a bioclimatic map. The second was to fit a multiple linear regression model with P/ETP as predicted variable and the FFT parameters as predictive variables. The regression model was then applied to obtain a map of the ratio P/ETP. The latter gave a second bioclimatic map. Foliar isophenology classes show a north–south decrease in phase value and increase in amplitude and mean NDVI values, thus reflecting the transition in climate conditions from hotter and drier to wetter and cooler. The model explains 92% (p‐value < 10−12) of the spatial variation in the P/ETP ratio. When using a single FFT parameter, no significant relationship was obtained. The three parameters provide complementary information to understand phenological variability in response to climate variability. Modelling bioclimate by means of monthly NDVI series summarized by Fourier analysis is an adequate tool to extend climate data where they are sparse. Copyright © 2007 Royal Meteorological Society
The effects of RANKL inhibition on fracture healing and bone strength in a mouse model of osteogenesis imperfecta
Authors: Delos Demetris , Yang Xu , Ricciardi Benjamin F. , Myers Elizabeth R. , Bostrom Mathias P.G. , Camacho Nancy Pleshko
Published: August 2007

Currently, the standard treatment for osteogenesis imperfecta (OI) is bisphosphonate therapy. Recent studies, however, have shown delayed healing of osteotomies in a subset of OI patients treated with such agents. The current study sought to determine the effects of another therapy, RANKL inhibition, on bone healing and bone strength in the growing oim/oim mouse, a model of moderate to severe OI. Mice [73 oim/oim and 69 wild‐type (WT)] were injected twice weekly with either soluble murine RANK (RANK‐Fc) (1.5 mg/kg) or saline beginning at 6 weeks of age. At 8 weeks of age, the animals underwent transverse mid‐diaphyseal osteotomies of the right femur. Therapy was continued until sacrifice at 2, 3, 4, or 6 weeks postfracture. At 6 weeks post‐fracture, greater callus area (6.59 ± 3.78 mm2 vs. 2.67 ± 2.05 mm2, p = 0.003) and increased radiographic intensity (mineral density) (0.48 ± 0.14 vs. 0.30 ± 0.80, p = 0.005) were found in the RANK‐Fc versus saline oim/oim group, indicating a delay in callus remodeling. Despite this delay, mechanical tests at 6 weeks postfracture revealed no significant differences in whole bone properties of stiffness and failure moment. Further, RANKL inhibition resulted in a greater failure moment and greater work to failure for the nonfractured contralateral WT bones compared to the nonfractured saline WT bones. Together, these results demonstrate that RANKL inhibition does not adversely affect the mechanical properties of healing bone in the oim/oim mice, and is associated with increased strength in intact bone in the WT mice. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:153–164, 2008
Sentinel node biopsy in oral squamous cell carcinoma
Authors: Civantos Francisco , Zitsch Robert , Bared Anthony
Published: August 2007

The clinical utility of sentinel node biopsy techniques for cutaneous melanoma has led multiple investigators to study the applicability of this approach to other solid tumors, including cancers of the upper aerodigestive tract, and especially the oral cavity. Preliminary data indicate that it may be useful for early oral cancers, with the exception of floor of mouth tumors, where technical challenges related to the proximity of the lymphatic basin remain a problem. A multi‐institutional pathologic validation trial, involving sentinel node biopsy followed by completion selective neck dissection, has completed accrual. While central step sectioning and immunohistochemistry remain to be completed and analyzed, routine pathologic techniques provided negative predictive values of 96% for oral cancer excluding floor of mouth lesions. Subsequent trials need to involve clinical follow‐up and evaluation for recurrence in the neck. We believe this technique may ultimately play a role in the management of early oral cancer. J. Surg. Oncol. 2007;96:330–336. © 2007 Wiley‐Liss, Inc.
Sentinel lymph node biopsy for breast cancer
Authors: Sato K. , Shigenaga R. , Ueda S. , Shigekawa T. , Krag D.N.
Published: August 2007

This manuscript is a brief discussion of the developments of the technology and concepts that led to modern procedures of radiotracer guided surgery of sentinel nodes (SNs) for breast cancer. The past section highlights some of the contributions by key persons involved with SN methods. The present section describes the magnitude of types of published material to date. The future section describes the major international trials and some important technical challenges yet to be solved. J. Surg. Oncol. 2007;96:322–329. © 2007 Wiley‐Liss, Inc.
Operative probe scintimetry with indium and technetium for colorectal cancer
Authors: Kuhn Joseph A. , Nochumson Joshua
Published: August 2007

Surgeons introduced the hand‐held gamma detection probe in combination with tumor‐directed monoclonal antibodies in patients with colorectal cancer. The clinicians conducted innovative research involving antibody chemistry and variation as well as radioactive dosimetry and decay. The results of these studies represented an era when surgeons began reporting on specific lesion detection and the impact of the antibody administration on the management of the patient. The summary of the important early trials involving monoclonal antibodies and probe scintimetry provides a valuable look into the early development of the antibody technology and a glimpse of potential future applications using the gamma detection probe. J. Surg. Oncol. 2007;96:290–296. © 2007 Wiley‐Liss, Inc.
The real effects of inflation in continuous versus discrete time sticky price models
Authors: Alex Ho Wai‐Yip , Yetman James
Published: August 2007

We demonstrate the important implications of the assumptions of discrete time in many sticky price models of the macroeconomy. For a given level of menu costs, discrete time models imply longer average contract length but smaller real effects of both trend inflation and monetary shocks than continuous time models. It is also feasible for a firm to enjoy full price flexibility in discrete time, while this would require paying infinite menu costs in continuous time, a distinction that is most important at high levels of trend inflation. Copyright © 2007 John Wiley & Sons, Ltd.
J‐modulated ADEQUATE experiments using different kinds of refocusing pulses
Authors: Thiele Christina M. , Bermel Wolfgang
Published: August 2007

Owing to the recent developments concerning residual dipolar couplings (RDCs), the interest in methods for the accurate determination of coupling constants is renascenting. We intended to use the J‐modulated ADEQUATE experiment by Kövér et al. for the measurement of 13C13C coupling constants at natural abundance. The use of adiabatic composite chirp pulses instead of the conventional 180° pulses, which compensate for the offset dependence of 13C 180° pulses, led to irregularities of the line shapes in the indirect dimension causing deviations of the extracted coupling constants. This behaviour was attributed to coupling evolution, during the time of the adiabatic pulse (2 ms), in the J‐modulation spin echo. The replacement of this pulse by different kinds of refocusing pulses indicated that a pair of BIPs (broadband inversion pulses), which behave only partially adiabatic, leads to correct line shapes and coupling constants conserving the good sensitivity obtained with adiabatic pulses. Copyright © 2007 John Wiley & Sons, Ltd.
Dependence of 35Cl NQR on hydrogen bonding and temperature in dichlorophenol–aniline charge transfer complexes
Authors: Ramananda D. , Ramesh K. P. , Uchil J.
Published: August 2007

The hydrogen‐bonded charge transfer complexes of aniline with π‐acceptors (or proton donors) such as 2,5‐, 2,6‐, 3,4‐ and 3,5‐dichlorophenol were prepared. The 35Cl nuclear quadrupole resonance (NQR) frequencies of these charge transfer complexes in the temperature range 77–300 K were measured to ascertain the existence or otherwise of a phase transition upon complex formation. Further, the NQR frequency and asymmetry parameter of the electric field gradient at the site of quadrupole nucleus were used to estimate the chemical bond parameters, namely ionic bond, double bond character of the carbon–chlorine(CCl) bond and the percentage charge transfer between the donor–acceptor components in charge transfer complexes. The effect of hydrogen bonding and temperature on the charge transfer process is analysed. Copyright © 2007 John Wiley & Sons, Ltd.
Complete assignments of 1H and 13C NMR spectral data for arylnaphthalene lignan lactones
Authors: da Silva Rosangela , Maia Ruas Marcelo , Marcos Donate Paulo
Published: August 2007

In this work we describe the complete 1H and 13C NMR analyses of three arylnaphtalene lignan lactones (taiwanin C, 4‐methyl dehydroretrodendrin and justicidin B) using modern NMR techniques such as gCOSY, nonedited gHSQC, gHMBC and NOE experiments. Complete assignment and homonuclear hydrogen coupling constant measurements were performed. Copyright © 2007 John Wiley & Sons, Ltd.
Analytical time integration for BEM axisymmetric acoustic modelling
Authors: Warszawski A. , Mansur W. J. , Soares D.
Published: August 2007

In this work, a numerical time‐domain approach to model acoustic wave propagation in axisymmetric bodies is developed. The acoustic medium is modelled by the boundary element method (BEM), whose time convolution integrals are evaluated analytically, employing the concept of finite part integrals. All singularities for space integration, present in the expressions generated by time integration, are treated adequately. Some applications are presented to demonstrate the validity of the analytical expressions generated for the BEM, and the results obtained with the present approach are compared with those generated by applying numerical time integration. Copyright © 2007 John Wiley & Sons, Ltd.
Treatment of wild‐type gastrointestinal stromal tumor (WT‐GIST) with imatinib and sunitinib
Authors: Murray Matthew , Hatcher Helen , Jessop Flora , Williams Denise , Carroll Nicholas , Bulusu Ramesh , Judson Ian
Published: August 2007

We report a rare case of advanced, metastatic gastrointestinal stromal tumor (GIST) in a young female. Molecular analysis of the tumor revealed wild‐type (WT) KIT and platelet derived growth factor receptor alpha (PDGFRA) gene status with no mutations characteristic of adult GIST. Despite this she had clinical benefit and evidence of radiological response to sequential treatment with the tyrosine kinase inhibitors imatinib and sunitinib. Pediatr Blood Cancer 2008;50:386–388. © 2007 Wiley‐Liss, Inc.