bluuebunny/crossref_metadata_2025 huggingface dataset:
What does geometric mean, mean geometrically? Assessing the utility of geometric mean and other size variables in studies of skull allometry
Authors: Coleman Mark N.
Published: December 2007

This study investigated the effects of using different size variables for interpretations of relative orbit size and mandibular robusticity. Thirty‐three skull measurements taken on 385 platyrrhines representing 12 of 16 New World monkey genera (in addition to body mass and total body length) were used singly and in combinations (by taking the geometric mean of all measurements) as size variables to produce relative size indices of orbit area and mandibular thickness. These indices were then compared to investigate which size variables proved effective at differentiating nocturnal from diurnal taxa and hard object from soft object feeders based upon results from previous biomechanical studies.

It was found that certain groups of size variables consistently produced the a priori expectations and resulted in lower coefficients of variation. The general principles shared by these size variables were that they sampled anatomically remote regions of the skull that appear to be functionally independent from the trait being evaluated and they were nearly always geometric mean combinations composed of a relatively high number (≥12) of large measurements. Suggestions are also presented for amending these principles for use with incomplete material such as fossils. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
An ectocranial lesion on the middle Pleistocene human cranium from Hulu Cave, Nanjing, China
Authors: Shang Hong , Trinkaus Erik
Published: December 2007

The earlier Middle Pleistocene human partial cranium from Hulu Cave, Tangshan, Nanjing (Hulu 1) exhibits an ectocranial lesion which covers most of the anterior neurocranium, largely between the temporal lines and extending from the supratoral sulcus to the anterior parietal bone. The endocranial surfaces and the remainder of the cranium (upper facial skeleton, lateral frontal bone, posterior parietal bones, and mid‐occipital bone) are normal. The healed lesion exhibits both resorption and the laying down of new bone. Differential diagnosis suggests that the lesion was caused by either trauma (broad compressive trauma, tensile trauma to the scalp, or partial scalp removal) or burning (with damage to scalp and superficial neurocranium). Dietary deficiencies, infection, and neoplastic disorders do not fit the lesion characteristics. The Hulu 1 specimen therefore joins a growing sample of Pleistocene Homo remains with nonfatal and nontrivial disorders. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Cannabinoids enhance susceptibility of immature brain to ethanol neurotoxicity
Authors: Hansen Henrik H. , Krutz Birte , Sifringer Marco , Stefovska Vanya , Bittigau Petra , Pragst Fritz , Marsicano Giovanni , Lutz Beat , Ikonomidou Chrysanthy
Published: December 2007

Objective

Marijuana and alcohol are most widely abused drugs among women of reproductive age. Neurocognitive deficits have been reported in children whose mothers used marijuana during pregnancy. Maternal consumption of ethanol is known to cause serious developmental deficits

Methods

Infant rats and mice received systemic injections of Δ9‐tetrahydrocannabinol (THC; 1–10mg/kg) or the synthetic cannabinoid WIN 55,212‐2 (1–10mg/kg), alone or in combination with subtoxic and toxic ethanol doses, and apoptotic neurodegeneration was studied in the brains

Results

Acute administration of THC (1–10mg/kg), the principal psychoactive cannabinoid of marijuana, markedly enhanced proapoptotic properties of ethanol in the neonatal rat brain. THC did not induce neurodegeneration when administered alone. Neuronal degeneration became disseminated and severe when THC was combined with a mildly intoxicating ethanol dose (3gm/kg), with the effect of this drug combination resembling the massive apoptotic death observed when administering ethanol alone at much higher doses. The detrimental effect of THC was mimicked by the synthetic cannabinoid WIN 55,212‐2 (1–10mg/kg) and counteracted by the CB1 receptor antagonist SR141716A (0.4mg/kg). THC enhanced the proapoptotic effect of the GABAA agonist phenobarbital and the N‐methyl‐D‐aspartate receptor antagonist dizocilpine. Interestingly, infant CB1 receptor knock‐out mice were less susceptible to the neurotoxic effect of ethanol. Furthermore, the CB1 receptor antagonist SR141716A ameliorated neurotoxicity of ethanol

Interpretation

These observations indicate that CB1 receptor activation modulates GABAergic and glutamatergic neurotransmission and primes the developing brain to suffer apoptotic neuronal death. Ann Neurol 2007
Cognitive deficits in Tsc1+/−mice in the absence of cerebral lesions and seizures
Authors: Goorden Susanna M. I. , van Woerden Geeske M. , van der Weerd Louise , Cheadle Jeremy P. , Elgersma Ype
Published: December 2007

Objective

Tuberous sclerosis complex (TSC) is characterized by brain lesions, epilepsy, increased incidence of mental retardation and autism. The causal link between lesion load and epilepsy on cognitive disabilities has been debated, and these factors explain only part of the intelligence quotient variability. A Tsc2 rat model of the disease provided evidence that the TSC genes are directly involved in neuronal function. However, these lesion‐ and epilepsy‐free animals did not show learning deficits, leaving open the possibility that the presence of brain lesions or epilepsy is a prerequisite for the cognitive deficits to fully develop. Here, we reinvestigated the relation among cerebral lesions, epilepsy, and cognitive function using Tsc1+/−mice.

Methods

We used immunocytochemistry and high‐resolution magnetic resonance imaging to study the presence of neuronal pathology in Tsc1+/−mice. We used the Morris water maze, fear conditioning, social interaction, and nest building test to study the presence of cognitive and social deficits.

Results

We observed no spontaneous seizures or cerebral lesions in the brains of Tsc1+/−mice. In addition, giant dysmorphic cells were absent, and spine number and dendritic branching appeared to be normal. Nevertheless, Tsc1+/−mice showed impaired learning in the hippocampus‐sensitive versions of the learning tasks and impaired social behavior.

Interpretation

Tsc1+/−mice show social and cognitive deficits in the absence of apparent cerebral pathology and spontaneous seizures. These findings support a model in which haploinsufficiency for the TSC genes leads to aberrations in neuronal functioning resulting in impaired learning and social behavior. Ann Neurol 2007
Effect of β‐cyclodextrin on the solid‐state synthesized polyaniline doped with hydrochloric acid
Authors: Ding Youjiang , Abdiryim Tursun , An Shuying , Nurulla Ismayil
Published: December 2007

Polyaniline (PANI) salts doped with hydrochloric acid were prepared by using solid‐state polymerization in the presence of β‐cyclodextrin (β‐CD) at room temperature. The fourier transform infrared (FTIR) spectra, ultraviolet‐visible absorption spectra, X‐ray diffraction patterns were used to characterize the molecular structures of these polymers. Cyclic voltammetry study and conductivity measurements were done to investigate their electrochemical behaviors. The morphology of polymers was studied by the scanning electron microscopy and transmission electron microscopy. The results showed that PANI salts prepared in the presence of β‐CD had different physicochemical characteristics compared with PANI salt prepared in the absence of β‐CD. When the molar ratio of aniline to β‐CD was 80/20, the obtained PANI salt displayed higher crystallinity, conductivity and electrochemical properties. However, these properties were opposite on condition that the molar ratio of aniline to β‐CD was 50/50. The results also revealed that the morphology of PANI salt was affected by β‐CD, especially at aniline/β‐CD molar ratio in the feed of 50/50, in which PANI salt displayed rodlike structure morphology with a diameter of near 80–100 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal properties and phase morphology of melt‐mixed poly(trimethylene terephthalate)/poly(hexamethylene isophthalamide) blends
Authors: Chiu Fang‐Chyou , Lee Hwung Yi , Wang Yu Hsuan
Published: December 2007

This work examines the thermal properties and phase morphology of melt‐mixed poly(trimethylene terephthalate) (PTT)/poly(hexamethylene isophthalamide) (PA 6I) blends. Two temperatures, i.e., 250 and 260°C, are used to prepare the blends, respectively. Differential scanning calorimetry results indicate the immiscible feature of the blends. It is thus concluded that the ester‐amide interchange reaction hardly occurred in the PTT/PA 6I blends. Depending on the composition and mixing temperature, the crystallization ability of PTT in the blends is either enhanced or hindered. Basically, a lower PA 6I content shifts the PTT melt crystallization to a higher temperature, whereas a higher PA 6I content causes an opposing outcome. The original complex melting behavior of neat PTT becomes more regular after the incorporation of 60 wt % or 80 wt % of PA 6I. Thermogravimetry analyses (TGA) show that the thermal stability of the blends improves as the PA 6I content increases. The two‐phased morphology of the blends is examined by scanning electron microscopy (SEM). Polarized light microscopy (PLM) results reveal that the PTT spherulites become coarser with the inclusion of PA 6I; only smaller/dispersed crystallites are observed in the blend with 20 wt % of PTT. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Highly Enantioselective Reactions of Configurationally Labile Epimeric Diamine Complexes of Lithiated S‐Benzyl Thiocarbamates
Authors: Lange Heiko , Bergander Klaus , Fröhlich Roland , Kehr Seda , Nakamura Shuichi , Shibata Norio , Toru Takeshi , Hoppe Dieter
Published: December 2007

Substitution reactions that employ primary‐carbamoyl‐protected arylmethanethiols are described. The enantiodetermining step was found to occur in the post‐deprotonation step as a dynamic thermodynamic resolution with a chiral bis(oxazoline) ligand. The configurationally labile lithium complexes were trapped with various electrophiles to yield different substitution products in good to excellent yields and enantiomeric excesses. The absolute configurations of the substitution products were determined, and the stereochemical pathway of the substitution reaction was elucidated for different classes of electrophiles. The temperature‐dependent epimerization process was monitored by 1H and 6Li NMR spectroscopy.
Driving positive development
Authors: Berndes Göran
Published: December 2007

The fact that renewable feedstocks are used is not sufficient in itself to make the biobased industry sustainable Copyright © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
Interface Engineering of Synthetic Pores: Towards Hypersensitive Biosensors
Authors: Mora Federico , Tran Duy‐Hien , Oudry Natalie , Hopfgartner Gerard , Jeannerat Damien , Sakai Naomi , Matile Stefan
Published: December 2007

Hydrophilic anchoring is introduced as a promising strategy to constructively control the various interactions of synthetic pore sensors with the surrounding biphasic environment. Artificial rigid‐rod β barrels are selected as classical synthetic multifunctional pores and random‐coil tetralysines are attached as hydrophilic anchors. The synthesis of this advanced pore is accomplished in 32 steps from commercially available starting materials. With regard to pore activity as such, the key impact of hydrophilic anchoring is a change from a Hill coefficient n<1 to n=4. This change confirms successful suppression of the competing self‐assembly with precipitation from the aqueous phase as the origin of the accomplished increase in pore activity. The hydrophilic anchors do not interfere with the blockage of the synthetic pore sensors by anionic analytes. In the case of stoichiometric binding of blockers (KD=EC50 of the pore; EC50=concentration needed to observe 50 % pore activity), however, the increase in pore activity achieved by hydrophilic anchoring results in improved pore blockage under high dilution conditions. Controls confirm that this increase does not occur with analytes that do not exhibit stoichiometric binding (KD>EC50). These results not only reveal stoichiometric binding as the expected origin of the sensitivity limit of synthetic pore sensors, they also provide promising solutions for this problem. The combination of hydrophilic anchoring with targeted pore formation emerges as a particularly promising strategy to further reduce effective pore concentrations. The scope and limitations of this approach are exemplified with pertinent analyte pairs that are essential for the sensing of sucrose, lactose, acetate, and glutamate with synthetic pores in samples from the supermarket.
Neuroendocrine secretory protein 55 (NESP55) in the spinal cord of rat: An immunocytochemical study
Authors: Li Yongling , Fischer‐Colbrie Reiner , Dahlström Annica
Published: December 2007

The immunohistochemical expression of a novel chromogranin‐like protein, neuroendocrine secretory protein 55 (NESP55), in the rat spinal cord was investigated. NESP55‐immunoreactive cells were detected in the ventral horn, intermediate laminae, and deep dorsal horn, comprising motoneurons, autonomic neurons, and interneurons throughout all spinal segments. Within laminae I–II of the dorsal horn, one or two NESP55‐positive cells were often seen. Nerve fibers also contained NESP55 immunoreactivity (IR) and were particularly prominent in the ventral horn. No nerve terminals/varicosities appeared to contain NESP55 in any spinal lamina. Double‐staining experiments revealed that a high proportion of the NESP55‐positive neurons were cholinergic. Moreover, NESP55‐IR in the motoneurons was evenly distributed in the whole cytoplasm with a finely granular appearance. In contrast, the fluorescent material in the preganglionic neurons was concentrated in the perinuclear region and largely overlapped with the trans‐Golgi network marker TGN38. Our data provide detailed morphological information on the distribution of NESP55‐IR in the rat spinal cord. Also, the differential intracellular expression of NESP55‐IR in the spinal motoneurons and autonomic neurons suggests that NESP55 may be processed into different secretory granules and may be involved in both constitutive and regulated pathways in these neurons. J. Comp. Neurol. 506:733–744, 2008. © 2007 Wiley‐Liss, Inc.
Ultrastructural evidence for pre‐ and postsynaptic localization of Cav1.2 L‐type Ca2+ channels in the rat hippocampus
Authors: Tippens Alyssa L. , Pare Jean‐Francois , Langwieser Nicole , Moosmang Sven , Milner Teresa A. , Smith Yoland , Lee Amy
Published: December 2007

In the hippocampal formation, Cav1.2 (L‐type) voltage‐gated Ca2+ channels mediate Ca2+ signals that can trigger long‐term alterations in synaptic efficacy underlying learning and memory. Immunocytochemical studies indicate that Cav1.2 channels are localized mainly in the soma and proximal dendrites of hippocampal pyramidal neurons, but electrophysiological data suggest a broader distribution of these channels. To define the subcellular substrates underlying Cav1.2 Ca2+ signals, we analyzed the localization of Cav1.2 in the hippocampal formation by using antibodies against the pore‐forming α1‐subunit of Cav1.2 (α11.2). By light microscopy, α11.2‐like immunoreactivity (α11.2‐IR) was detected in pyramidal cell soma and dendritic fields of areas CA1–CA3 and in granule cell soma and fibers in the dentate gyrus. At the electron microscopic level, α11.2‐IR was localized in dendrites, but also in axons, axon terminals, and glial processes in all hippocampal subfields. Plasmalemmal immunogold particles representing α11.2‐IR were more significant for small‐ than large‐caliber dendrites and were largely associated with extrasynaptic regions in dendritic spines and axon terminals. These findings provide the first detailed ultrastructural analysis of Cav1.2 localization in the brain and support functionally diverse roles of these channels in the hippocampal formation. J. Comp. Neurol. 506:569–583, 2008. © 2007 Wiley‐Liss, Inc.
Organization of connectivity of the rat presubiculum: II. Associational and commissural connections
Authors: Honda Yoshiko , Umitsu Yoshitomo , Ishizuka Norio
Published: December 2007

The regional, laminar, and longitudinal organization of intrinsic projections in the presubiculum was examined in the rat with the retrograde tracer horseradish peroxidase conjugated to wheat germ agglutinin and the anterograde tracer Phaseolus vulgaris‐leucoagglutinin. Cells of origin of intrinsic projections in the presubiculum were distributed in layers II and V, with almost none in layers III and VI. Projections from layer II cells were bilateral and confined to layers II and V and also to the deep portion of layer I, whereas projections from layer V cells were ipsilateral and confined largely to layer V, with fewer projections to layer II. Septotemporal and proximodistal differences in both the projection and the distribution of layer II cells were found: layer II cells in the septal and mid presubiculum, especially those located in the distal part, provided long projections to the temporal presubiculum, whereas layer II cells in the temporal presubiculum provided slightly shorter projections almost entirely within the mid and temporal presubiculum. Layer II cells aggregated massively in the distal portions of the septal and mid presubiculum, but very few layer II cells were found in the most proximal part, especially in the temporal presubiculum. On the other hand, in layer V, cells of origin and their terminals were diffusely and equally distributed throughout the entire proximodistal extent of the presubiculum. Layer V cells did not project longitudinally as far as layer II cells. These longitudinal connections, in layers II and V, make it possible to merge information conveyed by parallel pathways in the presubiculum. J. Comp. Neurol. 506:640–658, 2008. © 2007 Wiley‐Liss, Inc.
Plasma‐Assisted MOCVD of Titanium Oxide and its Composite Coatings Using Metallo‐organic Precursors
Authors: Arockiasamy S. , Raghunathan V. S. , Antony Premkumar P. , Kuppusami P. , Dasgupta A. , Parameswaran P. , Mallika C. , Nagaraja K. S.
Published: December 2007

Titanium oxide (TiO2) films and composite coatings with nickel were synthesized by plasma‐assisted, metal‐organic (PAMO) CVD using the MO complexes bis(2‐N‐(2‐hydroxy‐2‐methylethylimino)‐4‐pentanoate)titanium(IV) and N,N′‐ethylene‐bis(2,4‐pentanedion‐iminoato)nickel(II). The growth of such films was investigated in various plasma environments (Ar or N2) in the substrate temperature range 450–550 °C under a deposition pressure of 1–2 mbar. The phase identification using grazing incidence X‐ray diffraction (GIXRD) showed TiO2 crystallized in anatase form, while that of nickel in composite films was found to be a face centered cubic (fcc) structure. The surface morphology analysis using scanning electron microscopy (SEM) revealed a grainy and sponge‐like structure for TiO2 films, whereas smooth and densely packed agglomerates could be observed for Ni/TiO2 composite films. Chemical analysis by energy dispersive X‐ray (EDX) analysis showed the presence of titanium, nickel, and oxygen in the films. X‐ray photoelectron spectroscopy (XPS) confirmed the chemical state of the elements in the deposited composite films to be Ti+4 and Ni0. Prior to the deposition of TiO2 and its composite films, the Ti precursor was subjected to equilibrium vapor pressure measurements by employing thermogravimetric/differential thermal analysis (TG/DTA) in transpiration mode, which led to the value of 46.25 ± 2.7 kJ mol–1 for the standard enthalpy of sublimation (ΔH°sub).
Growth of Epitaxial MgB2 Thick Films with Columnar Structures by Using HPCVD
Authors: Seong W. K. , Huh J. Y. , Kang W. N. , Kim J.‐W. , Kwon Y.‐S. , Yang N.‐K. , Park J.‐G.
Published: December 2007

Epitaxial MgB2 thick films are grown on Al2O3 substrates at 600 °C by using the hybrid physical (HP)CVD technique. In order to obtain a high magnesium vapor pressure around the substrates, we use a special susceptor having a susceptor cap and achieve a very high growth rate of 0.17 μm min–1. Hexagonal‐shaped columnar structures are observed by cross‐sectional and planar‐view transmission electron microscope (TEM) images. For the 1.7 μm thick film, the Tc is observed to be 40.5 K with a Jc of 1.5 × 106 A cm–2 at 30 K. The vortex pinning mechanism by intercolumnar boundaries will be discussed.
The Effect of Film Thickness on the Suitability of Titanium Oxynitride (TiNxOy, x + y = 1) Films as Heat Mirrors – Formed by the Atmospheric Pressure CVD of TiCl4 and NH3
Authors: Hyett G. , Binions R. , Parkin I. P.
Published: December 2007

Films of titanium oxynitride are assessed for their potential as heat mirror coatings on window glass, as a function of the film thickness. The coatings are deposited from the atmospheric pressure (AP) chemical vapor reaction of TiCl4 and ammonia. The heat mirror properties are evaluated using transmission and reflection spectroscopy. The composition of the samples is determined by X‐ray photoelectron spectroscopy (XPS), and the thickness of the films by scanning electron microscopy (SEM). These results suggest that an effective heat mirror can be formed by a 100 nm thick coating of titanium oxynitride, which has a transmission of 49 % in the visible (610 nm), and a reflection of 46 % in the near infrared (1320 nm).
A flow cytometric protocol for detection of Cryptosporidium spp.
Authors: Barbosa Joana M. M. , Costa‐de‐Oliveira Sofia , Rodrigues Acácio G. , Hanscheid Thomas , Shapiro Howard , Pina‐Vaz Cidália
Published: December 2007

Cryptosporidium parvum is transmitted through water and can cause severe diarrhea. The diagnosis is usually based upon observer‐dependent microscopic detection of oocysts, with rather low sensitivity and specificity. Our objective was to optimize a flow cytometric (FC) protocol for the detection of C. parvum. A specific monoclonal antibody conjugated with R‐phycoerythrin was incubated with dead oocysts to determine the optimal antibody concentration. Serial concentrations of oocysts were stained with the optimized concentration and analyzed by FC. The lower detection limit was determined, and the possibility of cross‐reaction was investigated using prokaryotic and eukaryotic microorganisms. A FC protocol was optimized to detect oocysts in spiked human stools. The optimal antibody concentration was found to be 3.0 μg/ml. The lowest number detectable was 2 × 103 oocysts/ml. Staining procedure was specific, as no cross‐reactions were observed. This reliable and easy FC protocol allow the specific detection of Cryptosporidium oocysts, even at very low concentrations, which is important for public health and further studies of treatment efficacy. © 2007 International Society for Analytical Cytology.
Stacking and separation of protein derivatives of naphthalene‐2,3‐dicarboxaldehyde by CE with light‐emitting diode induced fluorescence detection
Authors: Chiu Tai‐Chia , Tu Wu‐Chun , Chang Huan‐Tsung
Published: December 2007

We describe the stacking and separation of proteins by CE under discontinuous conditions in conjunction with light‐emitting diode induced fluorescence (LEDIF) detection using a violet LED at 405 nm. The proteins were derivatized with naphthalene‐2,3‐dicarboxaldehyde (NDA) to form NDA–protein derivatives prior to CE‐LEDIF analysis. During the separation, poly(ethylene oxide) (PEO) solution containing CTAB enters from the cathodic inlet to the capillary via electroosomotic flow (EOF). The optimum conditions are: the capillary was filled with 50 mM glycine buffer (pH 9.0) containing 1.0 mM CTAB, NDA–protein derivatives were prepared in deionized water containing 1.0 mM CTAB, and 0.6% PEO was prepared in 50 mM glycine (pH 9.0) containing 2.0 mM CTAB. The analysis of four NDA–protein derivatives is fast (<3 min), with RSD <1.5% in terms of migration time. In order to improve the sensitivity of NDA–protein derivatives, a stacking approach based on increases in viscosity and electric field, as well as sieving was applied. The efficient stacking approach provides LODs (S/N = 3) of 2.41, 0.59, 0.61, and 4.22 nM for trypsin inhibitor, HSA, β‐lactoglobulin, and lysozyme, respectively. In addition, we also applied the stacking approach to determination of the concentration of HSA in one urine sample, which was determined to be 0.31 ± 0.05 μM (n = 3).
Protein extraction from Phoenix dactylifera L. leaves, a recalcitrant material, for two‐dimensional electrophoresis
Authors: Gómez‐Vidal Sonia , Tena Manuel , Lopez‐Llorca Luis Vicente , Salinas Jesús
Published: December 2007

This work was aimed at optimizing a protein extraction procedure for date palm (Phoenix dactylifera L.) leaves, a highly recalcitrant plant tissue for 2‐DE. Five protein extraction protocols based on different protein precipitation agents (TCA/acetone vs. phenol (Ph) methods) and protein resolubilization methods (physical treatments, e.g., sonication, shaking and/or heating) were tested. Ph/SDS extraction with methanol/ammonium acetate precipitation, followed by DOC preincubation and TCA/acetone precipitation and, finally, solubilization by shaking in rehydration solution was found to be the best protein extraction method. We conclude that DOC with TCA/acetone precipitation step eliminates interfering compounds, thus allowing efficient resolubilization of date palm leaf proteins. This method could be appropriate for proteomic studies such as date palm colonization by entomopathogenic fungi.
Impact of corrections for dynamic selection bias on forecasts of retention behavior
Authors: Li Yang , Mayer Walter J.
Published: December 2007

We investigate the impact of corrections for dynamic selection bias on forecasting accuracy in a multi‐period stay/leave model. While corrections for selection bias are needed for consistent coefficient estimates, they do not necessarily produce more accurate forecasts than uncorrected techniques. Theorem 1 shows that, apart from estimation errors, a shrinkage principle applies: the heterogeneity restriction imposed by uncorrected and combination techniques improves accuracy for forecasting individuals that leave, and hurts accuracy for forecasting individuals that stay. This has important implications for decision making because of the potential for asymmetric losses. We also present an illustrative empirical application and results from Monte Carlo experiments. We find that differences in relative accuracy vary directly with the degree of selection bias and inversely with the percentage of the initial population that stays.  Copyright © 2007 John Wiley & Sons, Ltd.
Forecasting interest rate swap spreads using domestic and international risk factors: evidence from linear and non‐linear models
Authors: Lekkos Ilias , Milas Costas , Panagiotidis Theodore
Published: December 2007

This paper explores the ability of factor models to predict the dynamics of US and UK interest rate swap spreads within a linear and a non‐linear framework. We reject linearity for the US and UK swap spreads in favour of a regime‐switching smooth transition vector autoregressive (STVAR) model, where the switching between regimes is controlled by the slope of the US term structure of interest rates. We compare the ability of the STVAR model to predict swap spreads with that of a non‐linear nearest‐neighbours model as well as that of linear AR and VAR models. We find some evidence that the non‐linear models predict better than the linear ones. At short horizons, the nearest‐neighbours (NN) model predicts better than the STVAR model US swap spreads in periods of increasing risk conditions and UK swap spreads in periods of decreasing risk conditions. At long horizons, the STVAR model increases its forecasting ability over the linear models, whereas the NN model does not outperform the rest of the models.  Copyright © 2007 John Wiley & Sons, Ltd.
Alcohol intake and risk of breast cancer defined by estrogen and progesterone receptor status—A meta‐analysis of epidemiological studies
Authors: Suzuki Reiko , Orsini Nicola , Mignone Laura , Saji Shigehira , Wolk Alicja
Published: December 2007

The association between alcohol consumption and an increased risk of breast cancer has been established. It is still unclear however, whether this relationship differs across the estrogen receptor (ER) and progesterone receptor (PR) tumors subtypes. To provide a quantitative assessment of the association between alcohol intake and the risk of ER‐/PR‐defined breast cancer, we conducted a meta‐analysis of cohort and case–control studies. Studies were identified by a literature search of PubMed through April 20, 2007 and by searching the reference lists of relevant articles. Summarized risk estimates (REs) with 95% confidence intervals (CIs) were calculated using random‐effects models. The summarized results of the meta‐analysis comparing the highest versus the lowest consumption categories showed statistically significant higher risks of developing all ER+ (27%), all ER− (14%), ER+PR+ (22%) and ER+PR− (28%), but not ER−PR− tumors. The dose–response meta‐analysis showed that an increase in alcohol consumption of 10 g of ethanol per day was associated with statistically significant increased risks for all ER+ (12%), all ER− (7%), ER+PR+ (11%) and ER+PR− (15%), but not ER−PR−. A statistically significant heterogeneity of the REs across all ER+ versus ER−PR− was observed (pheterogeneity = 0.02). The summarized results from studies with adjustment for postmenopausal hormone use, body mass index and family history of breast cancer were higher and statistically significantly different from those without. The observed positive associations with alcohol for ER+PR+ and ER+PR− tumors cannot be explained by estrogen‐dependent pathway only. Further studies need to clarify the biological mechanisms. © 2007 Wiley‐Liss, Inc.
The influence of Sr doses on the in vitro biocompatibility and in vivo degradability of single‐phase Sr‐incorporated HAP cement
Authors: Dagang Guo , Kewei Xu , Yong Han
Published: December 2007

In previous studies, we developed a new type of Sr‐incorporated hydroxyapatite cement (Sr‐HAC), which was shown to have many excellent physiochemical properties, by an ionic cement route (Guo et al., Biomaterials 2005;26:4073‐4083). As a further study, the main aims of this article were to examine the Sr‐HAC's in vitro biocompatibility, including acute toxicity, hemolytic reaction, pyrogen reaction, and cytoxicity, to evaluate its in vivo degradability during intramuscular and femur implantation, and also to investigate the influence of Sr doses on these properties. The in vitro results show that all of the Sr‐HAC samples exhibit satisfactory biocompatibility, and the Sr/(Sr+Ca) molar ratio has an important effect on these properties. For example, the Sr‐HAC with a Sr/(Sr+Ca) molar ratio of 5% (5% Sr‐HAC) has higher biocompatibility than both the one with a Sr/(Sr+Ca) molar ratio of 10% (10% Sr‐HAC) and the Sr‐free one. The in vivo results of both the rabbit intramuscular and femur implantation experiments show that the Sr‐HAC samples exhibit a much faster degradation rate than the Sr‐free one, and that this also depends on the Sr/(Sr+Ca) molar ratio. Specifically, the mean degradation rate of the 10% Sr‐HAC increases by an amplitude of 73.9 wt % compared with that of the Sr‐free HAC. In addition, the optical transmission photographs show that the Sr doses play an important role on the interface between the implants and the new bone. The energy dispersion X‐ray spectrum analysis indicates that there exists a gradient distribution of Sr element in the tight and bioactive interface between the implants and new bone, indicating that the Sr element takes a share in the mineralization of the new bone together with Ca element. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Effect of surface chemistry modification of functional gold nanoparticles on the drug accumulation of cancer cells
Authors: Song Min , Wang Xuemei , Li Jingyuan , Zhang Renyun , Chen Baoan , Fu Degang
Published: December 2007

In this report, we have explored the possibility to facilitate the drug delivery efficiency for cancer cells through the surface chemistry modification of gold nanoparticles (AuNPs), where the functional AuNPs were synthesized by the ligand exchange reaction between triphenyl phosphide‐stabilized precursor nanoparticles and mercaptopropionic acid. Our observations demonstrate that the combination of the anticancer drug daunorubicin with relevant AuNPs could be used as an efficient way to mark the cancer cells, which may afford the potential application for the early diagnosis of the respective cancers. Besides, the synergistic enhanced effect of the relevant gold nanoparticles on the drug uptake of target cancer cells could provide a new strategy to inhibit the multidrug resistance of the respective cancers. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 86A: 942–946, 2008
Polymer cell culture substrates with micropatterned carbon nanotubes
Authors: Eliason Marcus T. , Sunden Erik O. , Cannon Andrew H. , Graham Samuel , García Andrés J. , King William P.
Published: December 2007

This article presents study of the interactions between cells and micropatterned carbon nanotubes on a polymer cell culture substrate. The polymer substrates with patterned carbon nanotubes were fabricated using an imprint process, whereby the nanotubes were pressed into a polymer layer at high temperature. The patterned substrates featured 28 different nanotube patterns of microscale lanes and circles, where the feature sizes ranged from 9 to 76 μm. Osteoblast‐like cells were seeded on the substrates and cell alignment was quantified via fluorescent and electron microscopy. Many patterns were fabricated on each polymer substrate, allowing 28 different experiments on each cell culture substrate, which were tested over 10,000 cells. The cell response to the patterned nanotubes showed a maximum alignment to the microlane patterns of 55 ± 6% and no significant alignment to microcircle patterns. This work enables the study of cell response to a wider range of patterns featuring both the micro and nano length scales. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Therapeutic doses of radiation alter proliferation and attachment of osteoblasts to implant surfaces
Authors: Ahmad Mansur , Sampair Christopher , Nazmul‐Hossain Abu N. M. , Khurana Neerja , Nerness Andrew , Wutticharoenmongkol Patcharaporn
Published: December 2007

Osseointegration of implants in irradiated bone is inadequate. The effect of radiation on cell‐implant material interaction has not been adequately studied. The goal of this study was to investigate the effects of ionizing radiationon the proliferation, differentiation, and attachment of osteoblasts to commercially pure titanium (cpTi). Human fetal osteoblasts (hFOB) were irradiated either before or after plating in tissue culture (TC) dishes with or without cpTi disks. Radiation was single dose of 10 cGy, 25 cGy, 50 cGy, 1 Gy, 2 Gy, 4 Gy or 8 Gy. Cell proliferation was determined by counting trypsinized cells on 7 days after irradiation. Attachment of irradiated hFOB was measured indirectly by counting cells 2 and 6 h after plating. Differentiation was evaluated by alkaline phosphatase activity. Compared with nonirradiated sham controls, higher doses of radiation significantly reduced cell attachment and proliferation. Both proliferation and attachment were significantly lower on cpTi compared with TC. Attachment decreased based on the length of postirradiation period. Although differentiation was significantly enhanced by a dose of 8 Gy, proliferation was lowest. These initial studies show that effects of therapeutic doses of radiation on osteoblasts varied depending on the surface, time‐elapsed, and amount of radiation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Interaction of glycopolymers with human hematopoietic cells from cord blood and peripheral blood
Authors: Lee Yong‐Su , Park Keun‐Hong , Kim Tea‐Sik , Kim Jea‐Myeoung , Sohn In‐Sook , Park Jin‐Ki , Chang Won‐Kyong , Kim Dong‐Ku
Published: December 2007

Polystyrene derivatives, poly[N‐pvinylbenzyl‐O‐D‐glucopyranosyl‐(1‐4)‐D‐glucoamide] (PV Maltose) and poly[N‐p‐vinylbenzyl‐O‐mannopyranosyl‐(1‐4)‐D‐glucoamide] (PV Mannose), which contain glucose and mannose moieties, respectively, have the specific binding ability with murine hematopoietic cells. In this study, we confirm the ability of these glycopolymers to interact specifically with human hematopoietic stem cells (HSCs) and mature cells derived from human cord blood (CB) and peripheral blood (PB). Using fluorescence isothiocyanate (FITC)‐labeled glycopolymers, we observed that 98% to 93% of hematopoietic cells interacted very strongly with PV Mannose, and 63% of CB and 29% PB interacted with PV Maltose. Both glycopolymers bound better to cells from CB than from PB. Cytotoxic studies revealed that a 0.1 mM dose of PV Mannose induced apoptosis in 20% CB cells, in contrast to 3–5% PB cells. Furthermore, we demonstrated that all of CD34+ HSCs of both origins bound specifically to PV Mannose, whereas 33–47% bound to PV Maltose. In addition, the majority of B cells (CD19+), T cells (CD3+), monocytes (CD14+), and erythrocytes (CD235a+) bound to PV Mannose, but a lower percentage interacted with PV Maltose. In vivo study, bone marrow, spleen, and liver tissues in NOD‐SCID mice injected with PV Mannose conjugated CB, were detected PV Mannose positive hematopoietic cells. These data suggest that the use of PV Mannose and PV Maltose might be used for gene and drug delivery for hematopoietic cells and thus, may be useful in therapeutic settings. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Regeneration of dentin‐pulp complex with cementum and periodontal ligament formation using dental bud cells in gelatin‐chondroitin‐hyaluronan tri‐copolymer scaffold in swine
Authors: Kuo Tzong‐Fu , Huang An‐Ting , Chang Hao‐Hueng , Lin Feng‐Huei , Chen San‐Tai , Chen Rung‐Shu , Chou Cheng‐Hung , Lin Hsin‐Chi , Chiang Han , Chen Min‐Huey
Published: December 2007

The purpose of this study is to use a tissue engineering approach for tooth regeneration. The swine dental bud cells (DBCs) were isolated from the developing mandibular teeth, expanded in vitro, and cultured onto cylinder scaffold gelatin‐chrondroitin‐hyaluronan‐tri‐copolymer (GCHT). After culturing in vitro, the DBCs/GCHT scaffold was autografted back into the original alveolar socket. Hematoxylin and eosin (H&E) staining combined with immunohistochemical staining were applied for identification of regenerated tooth structure. After 36‐week post‐transplantation, tooth‐like structures, including well‐organized dentin‐pulp complex, cementum, and periodontal ligament, were evident in situ in two of six experimental animals. The size of the tooth structure (1 × 0.5 × 0.5 cm3 and 0.5 × 0.5 × 0.5 cm3 size) appeared to be dictated by the size of the GCHT scaffold (1 × 1 × 1.5 cm3). The third swine was demonstrated with irregular dentin‐bony like calcified tissue about 1 cm in diameter without organized tooth or periodontal ligament formation. The other three swine in the experimental group showed normal bone formation and no tooth regeneration in the transplantation sites. The successful rate of tooth regeneration from DBCs/GCHT scaffolds' was about 33.3%. In the control group, three swine's molar teeth buds were removed without DBCs/GCHT implantation, the other three swine received GCHT scaffold implants without DBCs. After evaluation, no regenerated tooth was found in the transplantation site of the control group. The current results using DBSs/GCHT scaffold autotransplantation suggest a technical breakthrough for tooth regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Three‐dimensional sonographic measurement of contralateral lung volume in fetuses with isolated congenital diaphragmatic hernia
Authors: Ruano Rodrigo , Aubry Marie‐Cécile , Barthe Bruno , Dumez Yves , Zugaib Marcelo , Benachi Alexandra
Published: December 2007

Purpose

To use 3‐dimensional sonography (3DUS) to measure contralateral lung volume and evaluate the potential of this measurement to predict neonatal outcome in isolated congenital diaphragmatic hernia (CDH).

Methods

Between January 2002 and December 2004, the contralateral lung volumes of 39 fetuses with isolated CDH were measured via 3DUS using rotational multiplanar imaging. The observed/expected contralateral fetal lung volume ratios (o/e‐ContFLVR) were compared with the lung/head ratio (LHR), observed/expected total fetal lung volume ratio (o/e‐TotFLVR), and postnatal outcome.

Results

Contralateral lung volumes are less reduced than total lung volumes in CDH. The bias and precision of 3DUS in estimating contralateral lung volumes were 0.99 cm3 and 1.11 cm3, respectively, with absolute limits of agreement ranging from −1.19 cm3 to +3.17 cm3. The o/e‐ContFLVR was significantly lower in neonatal death cases (median, 0.49 cm3; range, 0.22–0.99 cm3) than in survival cases (median, 0.58 cm3; range, 0.42–0.92 cm3 [p < 0.01]). Overall accuracy of the o/e‐ContFLVR, o/e‐TotFLVR, and LHR in predicting neonatal death were 67.7% (21/31), 80.7% (25/31), and 77.4% (24/31), respectively.

Conclusion

Although o/e‐ContFLVR can be precisely measured with 3DUS and can be used to predict neonatal death in CDH, it is less accurate than LHR and o/e‐TotFLVR for that purpose. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Promoters influence the kinetics of transgene expression following adenovector gene delivery
Authors: Chen Ping , Tian Jie , Kovesdi Imre , Bruder Joseph T.
Published: December 2007

Background

The kinetics of gene expression from adenovirus‐based delivery vectors will be an important variable influencing the efficacy and toxicity of these vectors. As different promoters have variable strengths and kinetic profiles, the optimal dose of a therapeutic transgene product over time may be achieved by varying the promoter.

Methods

We analyzed several viral and cellular promoters in the context of adenovector gene delivery in the mouse. The kinetics of transgene expression was evaluated following intramuscular and intravenous delivery.

Results

Transgene expression from the cytomegalovirus (CMV) promoter was rapidly down‐regulated in the tissues following intravenous administration of adenovectors. In contrast, transgene expression from the Rous sarcoma virus (RSV) promoter increased over time such that, at 3 weeks, expression was 10‐fold higher than that from the CMV promoter‐containing vector in all tissues. The kinetics of transgene expression from these vectors was similar when they were delivered via the intramuscular route in BALB/c, C57BL/6 and immunodeficient mice. Efficient repeat administration of an adenovirus vector, in the presence of neutralizing antibodies, was achieved in the skeletal muscle and transgene expression persisted with the same kinetics as in naïve animals.

Conclusions

These results demonstrate that the in vivo kinetics of transgene expression by adenovectors is greatly influenced by the promoter. Adenovectors can be designed to deliver a transient bolus or a sustained level of protein expression in the target tissue depending on the requirements for particular indications. These results have implications for both therapeutic and vaccine indications. Copyright © 2007 John Wiley & Sons, Ltd.
Quantitative motor unit potential analysis in the diaphragm: A normative study
Authors: Podnar Simon , Resman‐Gašperšič Anita
Published: December 2007

Although quantitative motor unit potential (MUP) analysis has an established role in other skeletal muscles, it has not been performed in the diaphragm. The aim of the present study was to test whether such studies are possible and to establish normative data. Twenty‐nine healthy volunteers (15 men), aged 21–65 years (median, 33 years), were studied using standard concentric needle electrodes, and equipment with the facility for template‐operated multi‐MUP analysis. Needle electrodes were inserted into the right medial recess of the seventh to ninth intercostal spaces. During MUP sampling, subjects were asked to hold their breath in partial inspiration for 5 s. At least 20 MUPs were obtained in 28 subjects. Diaphragmatic MUPs were confirmed to be much smaller than those of limb muscles. We found diaphragmatic quantitative MUP analysis to be possible in healthy volunteers. However, further studies in patient groups are needed to establish the feasibility and clinical value of such studies. Muscle Nerve, 2007
Preparation and cryogenic mechanical properties of epoxy resins modified by poly(ethersulfone)
Authors: Yang Guo , Zheng Bin , Yang Jiao‐Ping , Xu Guan‐Shui , Fu Shao‐Yun
Published: December 2007

A thermoplastic, poly(ethersulfone) (PES) was used to modify a bisphenol‐F based epoxy resin cured with an aromatic diamine. The initial mixtures before curing, prepared by melt mixing, were homogeneous. Scanning electron microscopy (SEM) micrographs of solvent‐etched fracture surfaces of the cured blends indicated that phase separation occurred after curing. The cryogenic mechanical behaviors of the epoxy resins were studied in terms of tensile properties and Charpy impact strength at cryogenic temperature (77 K) and compared to their corresponding behaviors at room temperature (RT). The addition of PES generally improved the tensile strength, elongation at break, and impact strength at both RT and 77 K except the RT tensile strength at 25 phr PES content. It was interesting to observe that and the maximum values of the tensile strength, elongation at break, and impact strength occurred at 20 phr PES content where a co‐continuous phase formed. Young's modulus decreased slightly with the increase of the PES content. Moreover, the tensile strength and Young's modulus at 77 K were higher than those at RT at the same composition, whereas the elongation at break and impact strength showed the opposite results. Finally, the differential scanning calorimetry analysis showed that the glass transition temperature (Tg) was enhanced by the addition of PES. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 612–624, 2008
An incremental development of the Mondex system in Event-B
Authors: Butler Michael , Yadav Divakar
Published: December 2007

A development of the Mondex system was undertaken using Event-B and its associated proof tools. An incremental approach was used whereby the refinement between the abstract specification of the system and its detailed design was verified through a series of refinements. The consequence of this incremental approach was that we achieved a very high degree of automatic proof. The essential features of our development are outlined. We also present some modelling and proof guidelines that we found helped us gain a deep understanding of the system and achieve the high degree of automatic proof.