bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of seeding technique and scaffold material on bone formation in tissue‐engineered constructs
Authors: Schliephake H. , Zghoul N. , Jäger V. , van Griensven M. , Zeichen J. , Gelinsky M. , Wülfing T.
Published: June 2008

The aim of the present study was to test the hypothesis that both scaffold material and the type of cell culturing contribute to the results of in vivo osteogenesis in tissue‐engineered constructs in an interactive manner. CaCO3 scaffolds and mineralized collagen scaffolds were seeded with human trabecular bone cells at a density of 5 × 106 cells/cm3 and were left to attach under standard conditions for 24 h. Subsequently, they were submitted to static and dynamic culturing for 14 days (groups III and IV, respectively). Dynamic culturing was carried out in a continuous flow perfusion bioreactor. Empty scaffolds and scaffolds that were seeded with cells and kept under standard conditions for 24 h served as controls (groups I and II, respectively). Five scaffolds of each biomaterial and from each group were implanted into the gluteal muscles of rnu rats for 6 weeks. Osteogenesis was assessed quantitatively by histomorphometry and expression of osteocalcin (OC) and vascular endothelial growth factor (VEGF) was determined by immunohistochemistry. CaCO3 scaffolds exhibited 15.8% (SD 3.1) of newly formed bone after static culture and 22.4% (SD 8.2) after dynamic culture. Empty control scaffolds did not show bone formation, and scaffolds after 24 h of standard conditions produced 8.2% of newly formed bone (SD 4.0). Differences between the controls and the scaffolds cultured for 14 days were significant, but there was no significant difference between static and dynamic culturing. Mineralized collagen scaffolds did not show bone formation in any group. There was a significant difference in the expression of OC within the scaffolds submitted to static versus dynamic culturing in the CaCO3 scaffolds. VEGF expression did not show significant differences between static and dynamic culturing in the two biomaterials tested. It is concluded that within the limitations of the study the type of biomaterial had the dominant effect on in vivo bone formation in small tissue‐engineered scaffolds. The culture period additionally affected the amount of bone formed, whereas the type of culturing may have had a positive effect on the expression of osteogenic markers but not on the quantity of bone formation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Effects of physiological mechanical strains on the release of growth factors and the expression of differentiation marker genes in human osteoblasts growing on Ti‐6Al‐4V
Authors: Kokkinos Petros A. , Zarkadis Ioannis K. , Kletsas Dimitris , Deligianni Despina D.
Published: June 2008

Mechanical loading factors at the bone‐implant interface are critical for the osseointegration and clinical success of the implant. The aim of the present investigation was to study the effects of mechanical strain on the orthopedic biomaterial Ti‐6Al‐4V/osteoblast interface, using an in vitro model. Homogeneous strain was applied to human bone marrow derived osteoblasts (HBMDOs) cultured on Ti‐6Al‐4V, at physiological levels (strain magnitudes 500 microstrain (με) and 1000 με, at frequencies of load application 0.5 Hz and 1 Hz), by a mechanostimulatory system, based on the principle of four‐point bending. Semi‐quantitative reverse transcription‐polymerase chain reaction (sqRT‐PCR) was used to determine the mRNA expression of Cbfa1 and osteocalcin at different loading conditions. The release of growth factors as a response to stretch was also investigated by transferring stretch‐conditioned media to nonstretched cells and by measuring their effect on the regulation of DNA synthesis. Mechanical loading was found to contribute to the regulation of osteoblast differentiation by influencing the level of the osteoblast‐specific transcription factor Cbfa1, both at the mRNA and protein level, and also the level of osteocalcin, which is regarded as the most osteoblast‐specific gene. Both genes were differentially expressed shortly after the application of different mechanical stimuli, in terms of strain frequency, magnitude, and time interval. Media conditioned from mechanically stressed HBMDOs stimulate DNA synthesis more intensely compared to media conditioned from unstressed control cultures, indicating that mechanical strain induces the release of a mitogenic potential that regulates cell proliferation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Histomorphometric evaluation of immediately loaded SSII implants of different surface treatments in a dog model
Authors: Jeon Woo‐Jin , Kim Su‐Gwan , Lim Sung‐Chul , Ong Joo L. , Oh Daniel Sunho
Published: June 2008

This study compared splint (experimental) and nonsplint (control) methods for immediately loaded implants and examined the bone–implant contact rate for smooth, oxidized, and resorbable blast medium (RBM) surfaces. The first through fourth mandibular premolars were extracted from six young adult dogs. Twelve weeks after extraction, implantation was performed at the extraction sites. The SSII OSSTEM implant had one of three surface treatments: smooth, oxidized, or RBM. Sixteen weeks after implantation, the dogs were euthanized; the hemimandibles were obtained and processed histologically to obtain nondecalcified sections. Longitudinal sections were made for each implant and analyzed using light microscopy. Independent of the splinting method, a significantly higher bone–implant contact was observed for implants with oxidized and RBM surfaces when compared with implants with smooth surfaces. Irrespective of the splinting method, immediately loaded implants with oxidized and RBM surfaces may result in higher bone–implant integration when compared with implants with smooth surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Subproteomic analysis of the mitochondrial proteins in rats 24 h after partial hepatectomy
Authors: Sun Qingju , Miao Mingyong , Jia Xuan , Guo Wei , Wang Lianghua , Yao Zhenzhen , Liu Chunli , Jiao Binghua
Published: June 2008

A 70% partial hepatectomy (70%PHx) induces cell proliferation until the original mass of the liver is restored. Mitochondria are involved directly in the process of liver regeneration (LR); however, their role in the early phase of LR is not clear. In an attempt to identify mitochondrial proteins that are correlated with the early phase of LR, we obtained a mitochondrial fraction via Nycodenz® density gradient centrifugation and subcellular proteomic analysis was performed. The mitochondrial proteins were separated by two‐dimensional gel electrophoresis and identified by mass spectrometry. Compared to the sham‐operation control group, 3 proteins were up‐regulated and 22 proteins were down‐regulated at 24 h after 70%PHx. We identified 22 differentially expressed proteins that were associated with carbohydrate metabolism, lipid metabolism, the respiratory chain and oxidation–phosphorylation, biotransformation and other metabolic pathways. Prohibitin, a proliferation‐regulating protein that was down‐regulated at 24 h after PHx, was analyzed by applying RNAi (PHBi) with BRL‐3A. This demonstrated a decreased mitochondrial membrane potential, implying a potential role in maintaining mitochondrial integrity. These results indicated that hepatic mitochondrial adaptations to LR after 70%PHx affect various cellular metabolic pathways, which advances our knowledge of the role of mitochondria in the early phase of LR. J. Cell. Biochem. 105: 176–184, 2008. © 2008 Wiley‐Liss, Inc.
Virus infection activates thyroid stimulating hormone synthesis in intestinal epithelial cells
Authors: Varghese Shaun , Montufar‐Solis Dina , Vincent Bryce H. , Klein John R.
Published: June 2008

The small intestine has been shown to be an extra‐pituitary site of thyroid stimulating hormone (TSH) production, and previous in vivo studies have shown that TSH synthesis localizes within areas of enteric virus infection within the small intestine; however, the cellular source of intestinal TSH has not been adequately determined. In the present study, we have used the murine MODE‐K small intestinal epithelial cell line to demonstrate both at the transcriptional level and as a secreted hormone, as measured in a TSHβ‐specific enzyme‐linked assay, that epithelial cells in fact respond to infection with reovirus serotype 3 Dearing strain by upregulating TSH synthesis. Moreover, sequence analysis of a PCR‐amplified TSHβ product from MODE‐K cells revealed homology to mouse pituitary TSHβ. These findings have direct functional implications for understanding a TSH immune‐endocrine circuit in the small intestine. J. Cell. Biochem. 105: 271–276, 2008. © 2008 Wiley‐Liss, Inc.
Efficient metal‐free aerobic oxidation of aromatic hydrocarbons utilizing aryl‐tetrahalogenated N‐hydroxyphthalimides and 1,4‐diamino‐2,3‐dichloroanthraquinone
Authors: Zhang Qiaohong , Chen Chen , Ma Hong , Miao Hong , Zhang Wei , Sun Zhiqiang , Xu Jie
Published: June 2008

BACKGROUND: Hydrocarbon oxidation reactions are central to numerous processes that convert bulk chemicals into useful and higher‐value products. In this investigation, an efficient metal‐free catalytic system for aerobic oxidation of aromatic hydrocarbons was successfully established by synthesizing a series of aryl‐tetrahalogenated N‐hydroxyphthalimides and applying these compounds with 1,4‐diamino‐2,3‐dichloroanthraquinone (DADCAQ).

RESULTS: Ethylbenzene was oxidized with 82.3% conversion and 86.9% selectivity to acetophenone catalyzed by the system of TCNHPI/DADCAQ under 0.3 MPa of molecular oxygen at 100 °C for 5 h. Other hydrocarbons were oxidized with high efficiency using this catalytic system. For example, indane can be converted completely to indan‐1‐one with 98.0% selectivity.

CONCLUSION: A highly efficient metal‐free catalytic system consisting of TCNHPI and DADCAQ was developed for the oxidation of aromatic hydrocarbons with molecular oxygen. Aryl‐halogen substituents served to significantly increase the activities of the catalytic system. The results in this study can form the basis for the design of an efficient hydrocarbon oxidation process. Copyright © 2008 Society of Chemical Industry
Activation of autophagy in retinal ganglion cells
Authors: Kim Seok Hwan , Munemasa Yasunari , Kwong Jacky M. K. , Ahn Jae Hong , Mareninov Sergey , Gordon Lynn K. , Caprioli Joseph , Piri Natik
Published: June 2008

Autophagy has been shown to be activated in neuronal cells in response to injury and suggested to have a cell‐protective role in neurodegenerative diseases. In this study, we investigated the activation of autophagy in retinal ganglion cells (RGCs) following optic nerve transection (ONT) and evaluated its effect on RGC survival. Expression of several autophagy‐related genes, including Atg5, Atg7, and Atg12, and autophagy markers microtubule‐associated protein 1 light chain 3–II (LC3‐II) and beclin‐1 were analyzed at the transcriptional or protein level 1, 3, and 7 days after ONT. Transcription of the Atg5, Atg7, and Atg12 genes was up‐regulated 1.5‐ to 1.8‐fold in the retina 3 days after ONT compared with that in the controls. Expression of Atg12 mRNA was increased 1.6‐fold 1 day after ONT. Seven days after ONT, expression of Atg5, Atg7, and Atg12 mRNA was comparable to that in the untreated retinas. Western blot analysis of proteins isolated from RGCs showed 1.6‐, 2.7‐, and 1.7‐fold increases in LC3‐II level 1, 3, and 7 days after ONT, respectively, compared with those in the controls. Expression of beclin‐1 was 1.7‐fold higher 1 day after RGCs were axotomized, but 3 and 7 days after ONT it was comparable to that of the control. Inhibition of autophagy with bafilomycin A1, 3‐methyladenine, and Wortmannin in RGC‐5 cells under serum‐deprived conditions decreased cell viability by approximately 40%. These results suggest possible activation of autophagy in RGCs after optic nerve transection and demonstrate its protective role in RGC‐5 cells maintained under conditions of serum deprivation. © 2008 Wiley‐Liss, Inc.
C‐jun N‐terminal kinase regulates the interaction between 14‐3‐3 and Bad in ethanol‐induced cell death
Authors: Han Jae Yoon , Jeong Eun Young , Kim Yoon Sook , Roh Gu Seob , Kim Hyun Joon , Kang Sang Soo , Cho Gyeong Jae , Choi Wan Sung
Published: June 2008

Activation of the c‐jun N‐terminal kinase (JNK) is known to be an important step during ethanol‐induced cell death, but it has yet to be identified how JNK regulates apoptosis. Therefore, we investigated the mechanism by which JNK induces cell death following ethanol treatment. Ethanol (6 g/kg, 20% in saline) was administered subcutaneously to postnatal 7 day rat pups. Twelve hours after the first ethanol administration, rat pups were decapitated, and extracts of total protein from cerebral cortices were prepared. Ethanol exposure induced phosphorylation of JNK but did not affect the expression levels of pro‐ and antiapoptotic proteins. Furthermore, interactions of phospho‐JNK (p‐JNK) with 14‐3‐3 as well as with Bad were enhanced in the cerebral cortices of ethanol‐treated rats. Pretreatment with JNK inhibitor (SP600125) of SH‐SY5Y cells inhibited JNK phosphorylation and interaction between p‐JNK and 14‐3‐3 resulting from ethanol. Furthermore, 14‐3‐3 interaction with Bad was diminished in the cerebral cortices of ethanol‐treated rats. These findings suggest that JNK induces Bad release from 14‐3‐3 by inhibiting their interaction. After this event, Bad binds to Bcl‐xL, releasing Bax from Bcl‐xL and leading to cell death. We hypothesize that JNK may play an important role during ethanol‐induced cell death via the inhibition of antiapoptotic function of 14‐3‐3 as well as activation of proapoptotic function of Bad. © 2008 Wiley‐Liss, Inc.
Impact of African orography and the Indian summer monsoon on the low‐level Somali jet
Authors: Chakraborty Arindam , Nanjundiah Ravi S. , Srinivasan J.
Published: June 2008

The low‐level jet (LLJ) over the Indian region, which is most prominent during the monsoon (June–September) season, has been studied with a general circulation model (GCM). The role of African orography in modulating this jet is the focus of this article. The presence of African orography intensifies the cross‐equatorial flow. Contrary to previous modelling studies we find that cross‐equatorial flow occurs even in the absence of African orography, though this flow is much weaker even when the Indian monsoon rainfall is high. However, the location of the meridional jet near the equator in the Somali region is linked to the Indian monsoon rainfall rather than to the land–sea contrast over Somalia. Also, the presence of African orography, and not the strength of the Indian monsoon, controls the vertical extent of the equatorial meridional wind.

In an aqua‐planet simulation, the cross‐equatorial flow occurs about 30° to the west of the rainfall maximum. Thus, the longitudinal location of the equatorial Somali jet depends upon the occurrence of monsoon heating, but the vertical structure of the jet is on account of the western boundary current in the atmosphere due to the East African highlands under the influence of monsoonal heat source. Copyright © 2008 Royal Meteorological Society
Interannual variability of boreal summer rainfall in the equatorial Atlantic
Authors: Gu Guojun , Adler Robert F.
Published: June 2008

Tropical Atlantic rainfall variations during boreal summer (June–July–August (JJA)) are quantified by means of a 28‐year (1979–2006) monthly precipitation dataset from the Global Precipitation Climatology Project (GPCP). Rainfall variability during boreal spring (March–April–May (MAM)) is also examined for comparison in that the most intense interannual variability is usually observed during this season. Comparable variabilities in the Atlantic maritime intertropical convergence zone (ITCZ) (15° –35°W) strength (PITCZ) are found during both seasons. Variations in the ITCZ's latitudinal location (LatITCZ) during JJA, however, are much weaker than during MAM.

PITCZ and LatITCZ are shown to be closely associated with sea surface temperature (SST) anomalies in both the tropical Atlantic and Pacific. Within the tropical Atlantic, the Atlantic Niño events (Atl3) and SST anomalies in the tropical North Atlantic (TNA) are the two major local factors modulating surface rainfall patterns and variations. Atl3 is significantly correlated with PITCZ and LatITCZ during JJA and MAM. TNA is significantly correlated to PITCZ during JJA but not to LatITCZ. In contrast, TNA is significantly correlated to LatITCZ during MAM but its correlation with PITCZ is weak.

The impact of the El Niño‐Southern Oscillation (ENSO) events (Nino3.4) is observed during both seasons, while the correlation between Nino3.4 and LatITCZ is slightly weak. However, with the effects of Atl3 and TNA removed, the ENSO tends to have a quite limited direct impact on the tropical Atlantic, specifically over the open ocean. High second‐order partial correlation between Nino3.4 and rainfall is generally confined to the western basin and over the northeastern South America. Therefore, during JJA, the two local SST modes are of dominance for the tropical Atlantic rainfall variability. Nevertheless, the ENSO seems to still play an active role in modulating surface zonal wind anomalies in the western basin and then the Atlantic Niño mode. Copyright © 2008 Royal Meteorological Society
In vivo contact stresses during activities of daily living after knee arthroplasty
Authors: D'Lima Darryl D. , Steklov Nikolai , Fregly Benjamin J. , Banks Scott A. , Colwell Clifford W.
Published: June 2008

We implanted an electronic knee prosthesis to measure tibial forces in vivo during activities of daily living after total knee arthroplasty. We used tibial forces and knee kinematic data collected in vivo to calculate contact stresses using finite element analysis. The polyethylene insert was modeled as an elastoplastic material, and predicted contact stresses were validated using pressure sensitive sensors. Peak contact stresses generated during walking were similar but about 18% lower than those calculated for International Standards Organization (ISO)‐recommended wear simulation conditions. Stair climbing generated higher contact stresses (32 MPa) than walking (26 MPa). However, both high flexion activities (lunge and kneel) generated even higher contact stresses, with the lunge activity generating the highest stresses (56 MPa). The activities that generated high contact stresses also resulted in high equivalent plastic strain. However, the lunge activity generated dramatically higher plastic equivalent strain than the other activities. In vivo measurement of kinematics, forces, and contact stresses may be used to develop more clinically relevant wear simulator protocols. Contact stresses generated during high flexion activities were substantially higher and were largely due to the reduced contact area in deep flexion rather than due to an increase in contact forces. Our results support the use of “high flexion” designs that improve contact conditions and preserve contact area at high flexion angles. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Therapeutic touch affects DNA synthesis and mineralization of human osteoblasts in culture
Authors: Jhaveri Ankur , Walsh Stephen J. , Wang Yatzen , McCarthy MaryBeth , Gronowicz Gloria
Published: June 2008

Complementary and alternative medicine (CAM) techniques are commonly used in hospitals and private medical facilities; however, the effectiveness of many of these practices has not been thoroughly studied in a scientific manner. Developed by Dr. Dolores Krieger and Dora Kunz, Therapeutic Touch is one of these CAM practices and is a highly disciplined five‐step process by which a practitioner can generate energy through their hands to promote healing. There are numerous clinical studies on the effects of TT but few in vitro studies. Our purpose was to determine if Therapeutic Touch had any effect on osteoblast proliferation, differentiation, and mineralization in vitro. TT was performed twice a week for 10 min each on human osteoblasts (HOBs) and on an osteosarcoma‐derived cell line, SaOs‐2. No significant differences were found in DNA synthesis, assayed by [3H]‐thymidine incorporation at 1 or 2 weeks for SaOs‐2 or 1 week for HOBs. However, after four TT treatments in 2 weeks, TT significantly (p = 0.03) increased HOB DNA synthesis compared to controls. Immunocytochemistry for Proliferating Cell Nuclear Antigen (PCNA) confirmed these data. At 2 weeks in differentiation medium, TT significantly increased mineralization in HOBs (p = 0.016) and decreased mineralization in SaOs‐2 (p = 0.0007), compared to controls. Additionally, Northern blot analysis indicated a TT‐induced increase in mRNA expression for Type I collagen, bone sialoprotein, and alkaline phosphatase in HOBs and a decrease of these bone markers in SaOs‐2 cells. In conclusion, Therapeutic Touch appears to increase human osteoblast DNA synthesis, differentiation and mineralization, and decrease differentiation and mineralization in a human osteosarcoma‐derived cell line. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1541–1546, 2008
The effect of muscle loading on flexor tendon‐to‐bone healing in a canine model
Authors: Thomopoulos Stavros , Zampiakis Emmanouil , Das Rosalina , Silva Matthew J. , Gelberman Richard H.
Published: June 2008

Previous tendon and ligament studies have demonstrated a role for mechanical loading in tissue homeostasis and healing. In uninjured musculoskeletal tissues, increased loading leads to an increase in mechanical properties, whereas decreased loading leads to a decrease in mechanical properties. The role of loading on healing tissues is less clear. We studied tendon‐to‐bone healing in a canine flexor tendon‐to‐bone injury and repair model. To examine the effect of muscle loading on tendon‐to‐bone healing, repaired tendons were either cut proximally (unloaded group) to remove all load from the distal phalanx repair site or left intact proximally (loaded group). All paws were casted postoperatively and subjected to daily passive motion rehabilitation. Specimens were tested to determine functional properties, biomechanical properties, repair‐site gapping, and bone mineral density. Loading across the repair site led to improved functional and biomechanical properties (e.g., stiffness for the loaded group was 8.2 ± 3.9 versus 5.1 ± 2.5 N/mm for the unloaded group). Loading did not affect bone mineral density or gapping. The formation of a gap between the healing tendon and bone correlated with failure properties. Using a clinically relevant model of flexor tendon injury and repair, we found that muscle loading was beneficial to healing. Complete removal of load by proximal transection resulted in tendon‐to‐bone repairs with less range of motion and lower biomechanical properties compared to repairs in which the muscle‐tendon‐bone unit was left intact. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Rapid degradation of the Cry3Bb1 protein from Diabrotica‐resistant Bt‐corn MON88017 during ensilation and fermentation in biogas production facilities
Authors: Rauschen Stefan , Nguyen Hang Thu , Schuphan Ingolf , Jehle Johannes A , Eber Sabine
Published: June 2008

BACKGROUND: Insect‐resistant transgenic corn is meeting a growing adoption in Europe. Corn is also the major substrate for biogas production, which has vastly increased in recent years. In areas with high insect pest pressure Bt‐corn silage will consequently be fed into biogas production facilities. To assess the potential risks of transgenic plants as energy crops we investigated the fate of the coleopteran‐specific protein Cry3Bb1 from MON88017 corn in the utilization chain of a farm‐scale biogas production facility using ELISA.

RESULTS: The mean Cry3Bb1 protein content in chaffed MON88017 plant material was 15 µg g−1. In silage the content decreased rapidly, with less than 20 ng g−1 detectable after 8 months. From the start of fermentation in the biogas reactor, only trace amounts of Cry3Bb1 could be detected. Conventional corn harvested alongside MON88017 with the same equipment showed a presence of transgenic plant material of around 0.5%. Analyses performed at two laboratories showed consistent and systematic differences in the concentrations of Cry3Bb1 measured with ELISA due to methodical differences.

CONCLUSIONS: An extensive degradation of Cry3Bb1 was observed in silage despite differences in ELISA measurements. The potential risk associated with the use of MON88017 silage is discussed on this basis. Copyright © 2008 Society of Chemical Industry
Synthesis, Electrochemical and Photovoltaic Properties of Multi‐Armed Polythiophenes with Triphenylamine Trivinylene as Conjugated Linker
Authors: Zou Yingping , Sang Guangyi , Wan Meixiu , Tan Songting , Li Yongfang
Published: June 2008

Three polythiophenes with 5%, 10% and 15% triphenylamine trivinylene (TPAV) as bridge linker, PT‐TPAV5, PT‐TPAV10 and PT‐TPAV15, were synthesized. The Wittig‐Horner‐Emmons reaction and the Stille method were employed to synthesize these polymers. The polythiophenes were subsequently used in bulk‐heterojunction polymer solar cells (PSCs) as donor materials. The polymers exhibited a striking and reversible color change after the oxidation of the polymer films. The power conversion efficiencies of the PSCs based on PT‐TPAV5, PT‐TPAV10 and PT‐TPAV15 as donors and PCBM as acceptor were 0.17%, 0.50%, and 0.35%, respectively, under the illumination of AM 1.5, 100 mW · cm−2.

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Electromagnetic Interference (EMI) Shielding Effectiveness of PP/PS Polymer Blends Containing High Structure Carbon Black
Authors: Al‐Saleh Mohammed H. , Sundararaj Uttandaraman
Published: June 2008

The morphological, electrical resistivity (ER), and electromagnetic interference (EMI) shielding effectiveness (SE) properties of poly(propylene) (PP), polystyrene (PS), PP/PS, and PP/PS/styrene–butadiene–styrene (SBS) blends filled with 10 vol.‐% high structure carbon black (CB) were studied. For the CB/PP/PS blends, TEM and SEM observations indicated that CB is preferentially localized in the PS phase. ER and EMI SE of the CB/PP/PS and CB/PP/PS/SBS blends were bounded between those of the PS composite (lower bound) and the PP composite (upper bound). In the PP/PS volume ratio ranging from (75/25) to (25/75), ER and EMI SE of the CB‐filled blends were independent of the PP/PS volume ratio. The EMI SE obtained by the 2 mm thick plates made of 10 vol.‐% CB‐filled (100/0)–(10/90) PP/PS blends are adequate for computers shielding applications.

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Effect of an Organically Modified Nanoclay on Low‐Surface‐Energy Materials of Polybenzoxazine
Authors: Fu Huei‐Kuan , Huang Chih‐Feng , Kuo Shiao‐Wei , Lin Han‐Ching , Yei Ding‐Ru , Chang Feng‐Chih
Published: June 2008

Novel low surface free energy materials of polybenzoxazine/organically modified silicate nanocomposites have been prepared and characterized. The CPC (cetylpyridinium chloride)/clay10%/poly(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazine) (PP‐a) material possesses an extremely low surface free energy (12.7 mJ · m−2) after 4 h curing at 200 °C, which is even lower than that of poly(tetrafluoroethylene) (22.0 mJ · m−2) calculated on the basis of the three‐liquid geometric method. X‐Ray photoelectron spectroscopy (XPS) shows a higher silicon content on the surface of the nanocomposites than for an average composition, which implies that the clay is more preferentially enriched on the outermost layer. In addition, the glass transition temperature (Tg) of the polybenzoxazine (PP‐a) in the nanocomposite is 22.6 °C higher and its thermal decomposition temperature is also 31.5 °C higher than the pure PP‐a. This finding provides a simple way to prepare low surface energy and high thermal stability materials.

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Supramolecular Gels Based on Multi‐Walled Carbon Nanotubes Bearing Covalently Attached Cyclodextrin and Water‐Soluble Guest Polymers
Authors: Klink Michael , Ritter Helmut
Published: June 2008

The preparation of associative networks containing multi‐walled carbon nanotubes (MWCNTs) with covalently attached cyclodextrin (CD) rings and poly[(isobutylene)‐co‐(maleic anhydride)‐co‐(maleic acid‐(4‐tert‐butylphenyl)amide)] in water is described in this study. The synthesis of CD containing MWCNTs is realized by an amidation reaction of oxidized MWCNTs with propargylamine followed by a 1,3‐dipolar cycloaddition with CD‐azide. Dispersion behavior indicated the high stability of these networks. An increase in viscosity compared to a solution of pure polymer as a cause of network formation is observed. The addition of a CD‐decomposing enzyme (taka‐diastase from Aspergillus oryzae) let the network collapse and results in sedimentation of the modified MWCNTs.

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A quantitative analysis of risk based on climatic factors on the roads in Iran
Authors: Habibi Nokhandan Majid , Bazrafshan Javad , Ghorbani Khalil
Published: June 2008

Climate factors such as rain, snow, strong winds, and icy roads are largely responsible for road accidents in various periods of the year and in various parts of the world. This study first examines the frequency of these factors in Iran. Using a quantitative method of risk analysis, the study identifies the potential for the climate risk affecting road safety and then prepares risk maps in a geographic information system (GIS) environment in various months of the year for the whole country. A study of risk maps shows that the months of the year may be divided into two periods in terms of accident potential: (1) April–October, when the roads face small or moderate numbers of accidents. In this period, strong winds play an important role in road accidents especially in windy regions such as the southeast and the northwest of the country, and (2) November–March, when the potential for road accidents gradually increases, reaching its peak in January. In this period, snow, rain, and icy roads are the most important causes of accidents especially on mountainous roads such as the roads in the Alborz and Zagros Mountains. Copyright © 2008 Royal Meteorological Society
1H, 13C NMR, X‐ray and conformational studies of new 1‐alkyl‐3‐benzoyl‐pyrazole and 1‐alkyl‐3‐benzoyl‐pyrazoline derivatives
Authors: López‐Cara Luisa C. , Carrión M. Dora , Camacho M. Encarnación , Gallo Miguel A. , Espinosa Antonio , Choquesillo‐Lazarte Duane , Gonzalez‐Pérez Josefa M. , Entrena Guadix Antonio
Published: June 2008

The 1H and 13C NMR resonances of 22 1‐alkyl‐pyrazole and 25 1‐alkyl‐pyrazoline derivatives were assigned completely using the concerted application of one‐ and two‐dimensional experiments (DEPT, gs‐HMQC and gs‐HMBC). Nuclear Overhauser enhancement (NOE) effects, conformational analysis and X‐ray crystallography confirm the preferred conformation of those compounds. Copyright © 2008 John Wiley & Sons, Ltd.
Conformational and structural analysis of exocyclic olefins and ketimines by multinuclear magnetic resonance
Authors: Montalvo‐González Rubén , Montalvo‐González J. Ascención , Ariza‐Castolo Armando
Published: June 2008

The 1H, 13C, and 15N NMR spectra of 5 exocyclic alkenes and 15 different ketimines obtained from cyclohexanone and derivatives using benzyl bromide and primary amines—are analyzed. Relative stereochemical and preferential conformations are determined by analyzing both the homonuclear coupling and the chemical shifts of the protons and carbon atoms in the aliphatic rings, which are directly related to the geometry of the double bond and the steric and electronic effects of the exocyclic group. In addition, the racemic mixture of the N‐(4‐methylcyclohexylidene)pyridine‐3‐amine derivative is resolved. Copyright © 2008 John Wiley & Sons, Ltd.
1.4T study of proton magnetic relaxation rates, iron concentrations, and plaque burden in Alzheimer's disease and control postmortem brain tissue
Authors: House Michael J. , St. Pierre Timothy G. , McLean Catriona
Published: June 2008

We measured proton magnetic longitudinal (R1) and transverse (R2) relaxation rates at 1.4T, iron concentrations, water contents, and amyloid plaque densities in postmortem brain tissue samples from three Alzheimer's disease (AD), two possible AD, and five control subjects. Iron concentrations and R1 were significantly higher in the temporal cortex region of our AD group compared to the controls. Frequency analyses showed that the observed trends of higher iron, R1, and R2 in AD gray matter regions were statistically significant. Simple regression models indicated that for AD and control gray matter the iron concentrations and water contents have significant linear correlations with R1 and R2. Multiple regression models based on iron concentrations and water contents were highly significant for all groups and tissue types and suggested that the effects of iron become more important in determining R1 and R2 in the AD samples. At 1.4T R1 and R2 are strongly affected by water content and to a lesser extent by variations in iron concentrations. The AD plaque density did not correlate with iron concentrations, water contents, R1, or R2, suggesting that increases in AD brain iron are not strongly related to the accumulation of amyloid plaques. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Linear inequalities among graph invariants: Using GraPHedron to uncover optimal relationships
Authors: Christophe Julie , Dewez Sophie , Doignon Jean‐Paul , Fasbender Gilles , Grégoire Philippe , Huygens David , Labbé Martine , Elloumi Sourour , Mélot Hadrien , Yaman Hande
Published: June 2008

Optimality of a linear inequality in finitely many graph invariants is defined through a geometric approach. For a fixed number of graph vertices, consider all the tuples of values taken by the invariants on a selected class of graphs. Then form the polytope which is the convex hull of all these tuples. By definition, the optimal linear inequalities correspond to the facets of this polytope. They are finite in number, are logically independent, and generate precisely all the linear inequalities valid on the class of graphs. The computer system GraPHedron, developed by some of the authors, is able to produce experimental data about such inequalities for a “small” number of vertices. It greatly helps in conjecturing optimal linear inequalities, which are then hopefully proved for any number of vertices. Two examples are investigated here for the class of connected graphs. First, all the optimal linear inequalities for the stability number and the number of edges are obtained. To this aim, a problem of Ore (1962) related to the Turán Theorem (1941) is solved. Second, several optimal inequalities are established for three invariants: the maximum degree, the irregularity, and the diameter. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Lower bounds for two‐period grooming via linear programming duality
Authors: Colbourn Charles J. , Quattrocchi Gaetano , Syrotiuk Violet R.
Published: June 2008

In a problem arising in grooming for two‐period optical networks, it is required to decompose the complete graph onnvertices into subgraphs each containing at mostCedges, so that the induced subgraphs on a specified set ofv≤nvertices each contain at mostC′ <Cedges. The cost of the grooming is the sum, over all subgraphs, of the number of vertices of nonzero degree in the subgraph. The optimum grooming is the one of lowest cost. An integer linear programming formulation is used to determine precise lower bounds on this minimum cost for all choices ofnandvwhen 1 ≤C′ <C≤ 3. In most cases, this approach determines not only the bound but also the specific structure of any grooming that could realize the bound. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Grooming for two‐period optical networks
Authors: Colbourn Charles J. , Quattrocchi Gaetano , Syrotiuk Violet R.
Published: June 2008

Minimizing the number of add‐drop multiplexers (ADMs) in a unidirectional SONET ring can be formulated as a graph decomposition problem. When traffic requirements are uniform and all‐to‐all, groomings that minimize the number of ADMs (equivalently, the drop cost) have been characterized for grooming ratio at most six. However, when two different traffic requirements are supported, these solutions do not ensure optimality. In two‐period optical networks,nvertices are required to support a grooming ratio ofCain the first time period, while in the second time period a grooming ratio ofCb,Cb<Ca, is required forv≤nvertices. This allows the two‐period grooming problem to be expressed as an optimization problem on graph decompositions ofKnthat embed graph decompositions ofKvforv≤n. Using this formulation, optimal two‐period groomings are found for small grooming ratios using techniques from the theory of graphs and designs. © 2008 Wiley Periodicals, Inc. NETWORKS, 2008
Some new large (Δ, 3)‐graphs
Authors: Gómez J.
Published: June 2008

We study the problem of finding large graphs with given degree Δ and diameter D = 3; that is, the construction of graphs with number of vertices as large as possible for a given degree Δ and diameter D = 3. There are two general methods to obtain large graphs: computer search and analytic methods. In this article, new ideas are proposed for analytic methods which allow us to improve the values for the entries (12,3), (13,3), and (14,3) in the table of the largest known (Δ,D)‐graphs. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
On the use of guided design search for discovering significant decision variables in the fixed‐charge capacitated multicommodity network design problem
Authors: Lewis Mark W.
Published: June 2008

A preprocessing technique, Guided Design Search (GDS), is presented for the fixed‐charge multicommodity capacitated network design (FCMD) problem. GDS applies design of experiment (DOE) principles in order to identify the critical edges in FCMD by analyzing the observed effects of tests using strictly generated sets of edge inclusion/exclusion decisions. Reasoning that these critical edges will exist in most of the high‐quality solutions, they are set to their appropriate value, resulting in a reduced solution space for FCMD. High‐quality solutions to this reduced FCMD were found quickly and often improved on those found for the unreduced problem. GDS is shown to dominate several other approaches for reducing the solution space. This success serves to broaden the applicability of experimental design screening and preprocessing techniques. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
In sickness or in health? Assessment of Early Iron Age human skeletons from Toutswe sites, east central Botswana
Authors: Mosothwane M. N. , Steyn M.
Published: June 2008

The general health of Early Iron Age (AD 700 to 1300) mixed farmers in east central Botswana has not been studied before. In this study the bones and teeth of 84 individuals from ten Toutswe sites were analysed for osteological manifestations of disease, with the aim of assessing the general health of the Toutswe communities. These individuals were aged between newborn and 75 years old, and include both sexes. Results indicate the presence of diseases commonly found in archaeological populations such as osteoarthritis, spina bifida occulta, cribra orbitalia, porotic hyperostosis and enamel hypoplasias. One possible case of DISH was found. The frequency of lesions was comparable with or even lower than at other similar sites, such as K2 and Mapungubwe and other parts of southern Africa. The samples represent communities with relatively low levels of stress and infections. This seems to support the results of the palaeodemographic analysis, which indicated that the Toutswe people were better off than those of neighbouring K2 and Mapungubwe. Copyright © 2008 John Wiley & Sons, Ltd.
Troponins and natriuretic peptides in the monitoring of anthracycline cardiotoxicity
Authors: Germanakis Ioannis , Anagnostatou Nikol , Kalmanti Maria
Published: June 2008

Anthracycline‐related cardiotoxicity has a substantial negative impact on long‐term survivors of childhood cancer. The detection of cardiotoxicity is currently based on echocardiography or radionuclide angiography. However, as they depict only the final outcome of myocardial injury in terms of reduced heart contractility, heart specific biomarkers of myocardial destruction or dysfunction could be advantageous by allowing for an earlier detection of cardiotoxicity. In the present study, the usefulness of cardiac troponins and natriuretic peptides, the most commonly used biomarkers of myocardial destruction and ventricular dysfunction respectively, to detect and to predict the development of anthracycline cardiotoxicity has been reviewed. Pediatr Blood Cancer 2008;51:327–333. © 2008 Wiley‐Liss, Inc.
Primary renal sarcomas in the Intergroup Rhabdomyosarcoma Study Group (IRSG) experience, 1972–2005: A report from the Children's Oncology Group
Authors: Raney Beverly , Anderson James , Arndt Carola , Crist Willam , Maurer Harold , Qualman Stephen , Wharam Moody , Wiener Eugene , Meyer William
Published: June 2008

Purpose

To describe clinical and pathologic characteristics and outcome of patients with renal sarcomas.

Patients/Methods

The IRSG database includes newly diagnosed patients <21 years old with rhabdomyosarcoma (RMS) or undifferentiated sarcoma (UDS). We identified patients with renal sarcoma and reviewed their charts.

Results

Ten of the 5,746 eligible IRSG patients enrolled from 1972 to 2005 had primary renal embryonal RMS (N = 6) or UDS (N = 4). Anaplasia was present in six (60%) of the tumors. Patients' ages ranged from 2.6 to 17.8 years. Tumor diameters ranged from 7 to 15 cm (median, 12 cm). At diagnosis, seven patients had localized disease: four underwent complete removal of tumor (Group I), two had microscopic residual (Group II), and one had gross residual tumor (Group III). Three patients had distant metastases (Group IV) in lungs and bone. Nine patients received vincristine, actinomycin D and cyclophosphamide (VAC). Two Group I patients received no radiation therapy (XRT); others received XRT to the primary tumor and to some metastatic sites. Nine patients achieved complete disappearance of tumor, six due to the initial operation. Tumors recurred in lung (N = 2) or brain (N = 1) in Group IV patients; each died within 16 months. The Group III patient died of Aspergillus pneumonia. The six Group I and II patients survive, continuously disease‐free, at 2.7–17.3 years (median, 4.7 years).

Conclusions

Patients with renal sarcomas often present with large tumors, many of them containing anaplastic features. Removing all gross disease at diagnosis, if feasible, is a critical component of treatment to curing patients with renal sarcoma. Pediatr Blood Cancer 2008;51:339–343. © 2008 Wiley‐Liss, Inc.
Lethal graft‐versus‐host disease in congenital neutropenia caused by p14 deficiency after allogeneic bone marrow transplantation from an HLA‐identical sibling
Authors: Bohn Georg , Hardtke‐Wolenski Matthias , Zeidler Cornelia , Maecker Britta , Sauer Martin , Sykora Karl‐Walter , Grigull Lorenz , Welte Karl , Klein Christoph
Published: June 2008

The molecular heterogeneity of severe congenital neutropenia (SCN) is increasingly recognized and may influence the risk‐benefit assessment of therapeutic strategies. We report on a patient with p14 deficiency who succumbed to severe grade IV graft‐versus‐host disease (GvHD) after a human leukocyte antigen‐identical bone marrow transplantion (BMT) from a sibling donor. Before BMT, in vitro generated p14‐deficient dendritic cells showed a markedly elevated tumor necrosis factor (TNF‐) α production upon toll‐like receptor stimulation. We hypothesize that p14 deficiency predisposes to GvHD through increased TNF‐α production. Adequate genetic testing is needed to prospectively assess potential risk factors for GvHD in defined SCN subgroups. Pediatr Blood Cancer 2008;51:436–438. © 2008 Wiley‐Liss, Inc.
A photoswitchable thioxopeptide bond facilitates the conformation‐activity correlation study of insect kinin
Authors: Huang Yun , Cong Zhiyuan , Yang Longfei , Dong Shouliang
Published: June 2008

Thioxopeptide bond ψ[CS–N], a nearly isosteric modification of the native peptide bond, was introduced into insect kinin active core pentapeptide to evaluate the impact of backbonecis/transphotoswitching on bioactivity. The thioxo analog Phe1‐Tyr2‐ψ[CS–N]‐Pro3‐Trp4‐Gly5‐NH2(ψ[CS–N]2‐kinin), was synthesized by Fmoc solid‐phase peptide strategy. The reversible photoswitching property was characterized via spectroscopic methods and HPLC, which showed that thecisconformer increased from 15.7 to 47.7% after 254 nm UV irradiation. A slow thermal reisomerization (t1/2= 40 min) permitted us to determine the cockroach hindgut myotropic activity of the thioxopeptide in the photostationary state. The results indicated that the activity increased significantly after UV irradiation and recovered to the ground level after thermal re‐equilibration. In the present study, by utilizing the phototriggered isomerization in a specific position of peptide backbone, we revealed that thecisψ[CS–N]2‐kinin conformer is the active conformation when interacting with kinin receptor on cockroach hindgut. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Lipid interactions of acylated tryptophan‐methylated lactoferricin peptides by solid‐state NMR
Authors: Greathouse Denise , Vostrikov Vitaly , McClellan Nicole , Chipollini Juan , Lay Jack , Liyanage Rohana , Ladd Taylor
Published: June 2008

Lactoferricin (LfB) is a 25‐residue innate immunity peptide released by pepsin from the N‐terminal region of bovine lactoferrin. A smaller amidated peptide, LfB6 (RRWQWR‐NH2) retains antimicrobial activity and is thought to constitute the “antimicrobial active‐site” (Tomita, Acta Paediatr Jpn. 1994; 36: 585–91). Here we report on N‐acylation of 1‐Me‐Trp5‐LfB6, Cn‐RRWQ[1‐Me‐W]R‐NH2, where Cn is an acyl chain having n = 0, 2, 4, 6 or 12 carbons. Tryptophan 5 (Trp5) was methylated to enhance membrane binding and to allow for selective deuteration at that position. Peptide/lipid interactions of Cn‐RRWQ[1‐Me‐W]R‐NH2 (deuterated 1‐Me‐Trp5 underlined), were monitored by solid state 31P NMR and 2H NMR. The samples consisted of macroscopically oriented bilayers of mixed neutral (dimyristoylphosphatidylcholine, DMPC) and anionic (dimyristoylphosphatidylglycerol, DMPG) lipids in a 3:1 ratio with Cn‐RRWQ[&1‐Me‐W]R‐NH2 peptides added at a 1:25 peptide to lipid ratio. 2H‐NMR spectra reveal that the acylated peptides are well aligned in DMPC:DMPG bilayers. The 2H NMR quadrupolar splittings suggest that the 1‐Me‐Trp is located in a motionally restricted environment, indicating partial alignment at the membrane interface. 31P‐NMR spectra reveal that the lipids are predominantly in a bilayer configuration, with little perturbation by the peptides. Methylation alone, in C0‐RRWQ[1‐Me‐W]R‐NH2, resulted in a 3–4 fold increase in antimicrobial activity against E. coli. N‐acylation with a C12 fatty acid enhanced activity almost 90 fold. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.