bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of model scramjet combustor flowfield
Authors: Wang Yuan‐Guang , Xu Xu , Cai Guo‐Biao
Published: June 2007

A new concept has been raised and adopted in this paper to enlarge the scope of the two‐dimensional model particularly for the purpose of dealing with three‐dimensional normal injection cases. Meanwhile, the method has a very good performance for its short cyclic period. The new idea was realized through special resolution with continuity equations; i.e., mass flow was directly added in the source term of the continuity equation. To prove the robustness of this illuminating method, comparisons using calculations were carried out, and the results are satisfactory. A model scramjet combustor tested on the free‐jet scramjet test facility was illustrated and underwent numerical calculations with the two‐dimensional program, adopting the above simplified injecting method. To simulate the chemical reaction process in the scramjet tunnel, a five‐species, single‐step reaction model was introduced in the calculation process. This research presents the major aerodynamic parameters and components of mass fraction distribution within the model combustor channel, which made it easy to observe and analyze the flowfield. Finally, wall pressure comparisons between the numerical and experimental results were carried out to verify the accuracy of the calculation model. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(5): 295– 302, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20159
Numerical oscillatory on the simulation of thermoacoustic waves
Authors: Jiping Liu , Zhijie Zhou , Daotong Chong , Junjie Yan
Published: June 2007

The SIMPLE algorithm for compressible flows is introduced to predict the thermoacoustic wave in a one‐dimensional closed region. The thermoacoustic waves are generated by an impulsive rise of the temperature on the left wall, while the other walls are kept at the initial temperature. Four different schemes are employed to deal with the convection‐diffusion terms, i.e., CD, FUD, QUICK, and MUSCL. The calculations and analysis show that numerical oscillation occurs under all four schemes, affected by the intensity of the waves, type of schemes, and other factors. The results are beneficial for the further investigation of the thermoacoustic waves and high efficiency scheme development. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(5): 265– 275, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20162
A hybrid LES/RANS approach using anisotropy‐resolving algebraic turbulence models for predicting turbulent heat transfer
Authors: Inuzuka Minoru , Abe Ken‐Ichi
Published: June 2007

In order to derive a possible path for developing a large eddy simulation (LES) applicable to high Reynolds‐number turbulent flows with heat transfer, a hybrid approach connecting LES with the Reynolds‐averaged Navier–Stokes (RANS) modeling in the near‐wall region is studied. In this study, an advanced non‐linear eddy‐viscosity model and a higher‐order extension of the generalized gradient diffusion hypothesis model are introduced to resolve the near‐wall turbulence and turbulent heat transfer more correctly. To investigate the model performance in detail, the proposed model is applied to fully developed plane channel flows with various grid resolutions. The present model provides encouraging results for further development of this kind of hybrid LES/RANS model. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(5): 249–264, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20163
A model for predicting behavioural sleep problems in a random sample of Australian pre‐schoolers
Authors: Hall Wendy A. , Zubrick Stephen R. , Silburn Sven R. , Parsons Deborah E. , Kurinczuk Jennifer J.
Published: June 2007

Behavioural sleep problems (childhood insomnias) can cause distress for both parents and children. This paper reports a model describing predictors of high sleep problem scores in a representative population‐based random sample survey of non‐Aboriginal singleton children born in 1995 and 1996 (1085 girls and 1129 boys) in Western Australia. Longitudinal repeated data were collected up to age 4 years by caregiver report. Children's sleep rhythmicity levels in their first year, as well as conflicted and lax parenting in their second year, predicted higher scores on the sleep problem scale from the Child Behaviour Checklist/2–3 in the children's third year. Higher scores on the sleep problem scale in the children's third year predicted higher scores on the aggressive behaviour subscale of the Child Behaviour Checklist/4–16. The results support a model in which sleep problems mediated the relationship between parental conflict and aggressive behaviour, even when controlling for maternal depression, which has been associated with children's aggressive behaviour. Copyright © 2007 John Wiley & Sons, Ltd.
Smokeless tobacco and increased risk of hypopharyngeal and laryngeal cancers: A multicentric case–control study from India
Authors: Sapkota Amir , Gajalakshmi Vendhan , Jetly Dhaval H. , Roychowdhury Soma , Dikshit Rajesh P. , Brennan Paul , Hashibe Mia , Boffetta Paolo
Published: June 2007

Hypopharyngeal and laryngeal cancers are among the most common cancers in India. In addition to smoking, tobacco chewing may be a major risk factor for some of these cancers in India. Using data from a multicentric case–control study conducted in India that included 513 hypopharyngeal cancer cases, 511 laryngeal cancer cases and 718 controls, we investigated smoking and chewing tobacco products as risk factors for these cancers. Bidi smoking was a stronger risk factor compared to cigarette smoking for cancer of the hypopharynx (ORbidi 6.80 vs. ORcig 3.82) and supraglottis (ORbidi 7.53 vs. ORcig 2.14), while the effect of the 2 products was similar for cancer of the glottis (ORbidi 5.32 vs. ORcig 5.74). Among never‐smokers, tobacco chewing was a risk factor for hypopharyngeal cancer, but not for laryngeal cancer. In particular, the risk of hypopharyngeal cancer increased with the use of Khaini (OR 2.02, CI 0.81–5.05), Mawa (OR 3.17, CI 1.06–9.53), Pan (OR 3.34, CI 1.68–6.61), Zarda (OR 3.58, CI 1.20–10.68) and Gutkha (OR 4.59, CI 1.21–17.49). A strong dose‐response relationship was observed between chewing frequency and the risk of hypopharyngeal cancer (ptrend < 0.001). An effect of alcohol on cancer of the hypopharynx and supraglottis was observed only among daily drinkers (OR 2.22, CI 1.11–4.45 and OR 3.76, CI 1.25–11.30, respectively). In summary, this study shows that chewing tobacco products commercially available in India are risk factors for hypopharyngeal cancer, and that the potency of Bidi smoking may be higher than that of cigarette smoking for hypopharyngeal and laryngeal cancers. © 2007 Wiley‐Liss, Inc.
Modulating metastasis by a lymphangiogenic switch in prostate cancer
Authors: Brakenhielm Ebba , Burton Jeremy B. , Johnson Mai , Chavarria Nelson , Morizono Kouki , Chen Irvin , Alitalo Kari , Wu Lily
Published: June 2007

Prostate cancer dissemination is difficult to detect in the clinic, and few treatment options exist for patients with advanced‐stage disease. Our aim was to investigate the role of tumor lymphangiogenesis during metastasis. Further, we implemented a noninvasive molecular imaging technique to facilitate the assessment of the metastatic process. The metastatic potentials of several human prostate cancer xenograft models, LAPC‐4, LAPC‐9, PC3 and CWR22Rv‐1 were compared. The cells were labeled with luciferase, a bioluminescence imaging reporter gene, to enable optical imaging. After tumor implantation the animals were examined weekly during several months for the appearance of metastases. Metastatic lesions were confirmed by immunohistochemistry. Additionally, the angiogenic and lymphangiogenic profiles of the tumors were characterized. To confirm the role of lymphangiogenesis in mediating metastasis, the low‐metastatic LAPC‐9 tumor cells were engineered to overexpress VEGF‐C, and the development of metastases was evaluated. Our results show CWR22Rv‐1 and PC3 tumor cell lines to be more metastatic than LAPC‐4, which in turn disseminates more readily than LAPC‐9. The difference in metastatic potential correlated with the endogenous production levels of lymphangiogenic growth factor VEGF‐C and the presence of tumor lymphatics. In agreement, induced overexpression of VEGF‐C in LAPC‐9 enhanced tumor lymphangiogenesis leading to the development of metastatic lesions. Taken together, our studies, based on a molecular imaging approach for semiquantitative detection of micrometastases, point to an important role of tumor lymphatics in the metastatic process of human prostate cancer. In particular, VEGF‐C seems to play a key role in prostate cancer metastasis. © 2007 Wiley‐Liss, Inc.
The E8 repression domain can replace the E2 transactivation domain for growth inhibition of HeLa cells by papillomavirus E2 proteins
Authors: Stubenrauch Frank , Straub Elke , Fertey Jasmin , Iftner Thomas
Published: June 2007

Continuous expression of the human papillomavirus (HPV) oncoproteins E6 and E7 is required for the growth of cervical cancer cell lines. So far, only the overexpression of the wild type papillomavirus E2 protein has been shown to induce growth arrest in HPV18‐positive HeLa cells by repressing E6/E7 transcription. Growth arrest by E2 requires the aminoterminal transcription activation domain in addition to the carboxyterminal DNA‐binding domain. Several papillomaviruses such as the carcinogenic HPV31 express in addition to E2 an E8∧E2C fusion protein in which the E8 domain, which is required for repression of replication and transcription, replaces the E2 activation domain. In this report, we demonstrate that the HPV31 E8∧E2C protein is able to inhibit the growth of HeLa cells but not of HPV‐negative C33A cervical cancer cells. Growth repression by E8∧E2C correlates with repression of the endogenous HPV18 E6/E7 promoter and the reappearance of E6‐ and E7‐regulated p53, pRb and p21 proteins, suggesting that E8∧E2C inhibits growth by reactivating dormant tumor suppressor pathways. Growth inhibition requires an intact E8 repression domain in addition to the carboxyterminal E2C DNA binding domain. Chromatin immunoprecipitation experiments suggest that the E8 repression domain enhances binding to the HPV18 promoter sequence in vivo. In summary, our results demonstrate that the small E8 repression domain can functionally replace the large E2 transactivation domain for growth inhibition of HeLa cervical cancer cells. © 2007 Wiley‐Liss, Inc.
Intakes of coffee, tea, milk, soda and juice and renal cell cancer in a pooled analysis of 13 prospective studies
Authors: Lee Jung Eun , Hunter David J. , Spiegelman Donna , Adami Hans‐Olov , Bernstein Leslie , van den Brandt Piet A. , Buring Julie E. , Cho Eunyoung , English Dallas , Folsom Aaron R. , Freudenheim Jo L. , Gile Graham G. , Giovannucci Edward , Horn‐Ross Pamela L. , Leitzmann Michael , Marshall James R. , Männistö Satu , McCullough Marjorie L. , Miller Anthony B. , Parker Alexander S. , Pietinen Pirjo , Rodriguez Carmen , Rohan Thomas E. , Schatzkin Arthur , Schouten Leo J. , Willett Walter C. , Wolk Alicja , Zhang Shumin M. , Smith‐Warner Stephanie A.
Published: June 2007

Specific beverage intake may be associated with the risk of renal cell cancer through a diluting effect of carcinogens, alterations of hormone levels, or other changes in the renal tubular environment, but few prospective studies have examined these associations. We evaluated the associations between coffee, tea, milk, soda and fruit and vegetable juice intakes and renal cell cancer risk in a pooled analysis of 13 prospective studies (530,469 women and 244,483 men). Participants completed a validated food‐frequency questionnaire at baseline. Using the primary data, the study‐specific relative risks (RRs) were calculated and then pooled using a random effects model. A total of 1,478 incident renal cell cancer cases were identified during a follow‐up of 7–20 years across studies. Coffee consumption was associated with a modestly lower risk of renal cell cancer (pooled multivariate RR for 3 or more 8 oz (237 ml) cups/day versus less than one 8 oz (237 ml) cup/day = 0.84; 95% CI = 0.67–1.05;pvalue, test for trend = 0.22). Tea consumption was also inversely associated with renal cell cancer risk (pooled multivariate RR for 1 or more 8 oz (237 ml) cups/day versus nondrinkers = 0.85; 95% CI = 0.71–1.02;pvalue, test for trend = 0.04). No clear associations were observed for milk, soda or juice. Our findings provide strong evidence that neither coffee nor tea consumption increases renal cell cancer risk. Instead, greater consumption of coffee and tea may be associated with a lower risk of renal cell cancer. © 2007 Wiley‐Liss, Inc.
Fibronectin silanized titanium alloy: A bioinductive and durable coating to enhance fibroblast attachment in vitro
Authors: Middleton C.A. , Pendegrass C.J. , Gordon D. , Jacob J. , Blunn G.W.
Published: June 2007

Long term success of percutaneous implants is dependent on soft tissue attachment to prevent infection and epithelial downgrowth, which leads to failure of the implant. Fibronectin coatings are known to enhance fibroblast attachment in vitro, but are subject to desorption from serum protein competition in vivo. This paper quantifies the binding of fibronectin to titanium alloy by silanization and the durability of this attachment when soaked in protein‐rich fluid compared with adsorbed fibronectin. The biological activity of fibronectin bound to silanized titanium alloy was confirmed by analyzing cell area, morphology, immunolocalization of focal contacts, and metabolism of dermal fibroblasts. This was compared with both adsorbed fibronectin and uncoated titanium alloy. Silanized titanium alloy bound over twice the amount of fibronectin compared to untreated titanium alloy. On soaking in fetal calf serum there was no significant loss of fibronectin (p = 0.589) from the silanized surface but a significant 44% loss (p = 0.002) from untreated surfaces. Fibroblasts on silanized fibronectin had significantly larger cell areas and more vinculin focal contact markers when compared to untreated surfaces (p < 0.005). The results confirm the durability of silanized fibronectin from protein competition and bioactive effect on fibroblasts. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Effects on coagulation of a synthetic heparan mimetic given intraperitoneally or orally
Authors: Charef Said , Petit Emmanuel , Barritault Denis , Courty José , Caruelle Jean‐Pierre
Published: June 2007

OTR4120, which belongs to a family of heparan sulfate‐mimetic polymers, promotes tissue repair when injected locally in doses of a few micrograms. As OTR4120 is a sulfated polysaccharide, we investigated its possible role on the coagulation cascade. We used both in vitro and in vivo assays. Increases in clotting times (thrombin time, prothrombin time, and activated partial thromboplastin time) occurred with OTR4120 in doses at least 10 times lower than heparin. OTR4120 dose‐dependently inhibited the biological activity of thrombin and bound thrombin with an affinity of 14 ± 2 nM. SDS‐PAGE showed that OTR4120 induced the formation of covalently linked complexes between antithrombin III or heparin cofactor II and thrombin. OTR4120 induced anticoagulant effects, and antithrombin activity was greatest 90 min after intraperitoneal injection. No bleeding or significant platelet count changes occurred with doses smaller than 55 mg/kg. Interestingly, orally administered OTR4120 crossed the gastrointestinal barrier and, in a dose of 70 mg/kg, induced significant ex vivo antithrombotic activity in the bloodstream. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Transglutaminase crosslinked gelatin as a tissue engineering scaffold
Authors: Yung C.W. , Wu L.Q. , Tullman J.A. , Payne G.F. , Bentley W.E. , Barbari T.A.
Published: June 2007

Gelatin is one of the most commonly used biomaterials for creating cellular scaffolds due to its innocuous nature. In order to create stable gelatin hydrogels at physiological temperatures (37°C), chemical crosslinking agents such as glutaraldehyde are typically used. To circumvent potential problems with residual amounts of these crosslinkers in vivo and create scaffolds that are both physiologically robust and biocompatible, a microbial transglutaminase (mTG) was used in this study to enzymatically crosslink gelatin solutions. HEK293 cells encapsulated in mTG‐crosslinked gelatin proliferated at a rate of 0.03 day‐1. When released via proteolytic degradation with trypsin, the cells were able to recolonize tissue culture flasks, suggesting that cells for therapeutic purposes could be delivered in vivo using an mTG‐crosslinked gelatin construct. Upon submersion in a saline solution at 37°C, the mTG‐crosslinked gelatin exhibited no mass loss, within experimental error, indicating that the material is thermally stable. The proteolytic degradation rate of mTG‐crosslinked gelatin at RT was slightly faster than that of thermally‐cooled (physically‐crosslinked) gelatin. Thermally‐cooled gelatin that was subsequently crosslinked with mTG resulted in hydrogels that were more resistant to proteolysis. Degradation rates were found to be tunable with gelatin content, an attribute that may be useful for either long‐time cell encapsulation or time‐released regenerative cell delivery. Further investigation showed that proteolytic degradation was controlled by surface erosion. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Effect of ionic activity products on the structure and composition of mineral self assembled on three‐dimensional poly(lactide‐co‐glycolide) scaffolds
Authors: Shin Kyungsup , Jayasuriya Ambalangodage C. , Kohn David H.
Published: June 2007

A biomimetic approach involving the self‐assembly of mineral within the pores of three‐dimensional porous polymer scaffolds is a promising strategy to integrate advantages of inorganic and organic phases into a single material for hard tissue engineering. Such a material enhances the ability of progenitor cells to differentiate down an osteoblast lineage in vitro and in vivo, compared with polymer scaffolds. The mechanisms regulating mineral formation in this one‐step process, however, are poorly understood, especially the effects of ionic activity products (IP) of the mineralizing solution and incubation time. The aims of this study were to define the structure and composition of mineral formed within the pores of biodegradable polymer scaffolds as a function of IP and time. Three‐dimensional poly(lactide‐co‐glycolide) scaffolds were fabricated by solvent casting/particulate leaching and incubated for 4–16 days in six variants of simulated body fluid whose IPs were varied by adjusting ionic concentrations. Scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy demonstrated the formation of carbonated apatite with sub‐micrometer sized crystals that grew into spherical globules extending out of the scaffold pore surfaces. As IP increased, more mineral grew on the scaffold pore surfaces, but the apatite became less crystalline and the Ca/P molar ratio decreased from 1.63 ± 0.005 to 1.51 ± 0.002. Since morphology, composition, and structure of mineral are factors that affect cell function, this study demonstrates that the IP of the mineralizing solution is an important modulator of material properties, potentially leading to enhanced control of cell function. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Phase transformation, roughness, and microhardness of artificially aged yttria‐ and magnesia‐stabilized zirconia femoral heads
Authors: Roy M.E. , Whiteside L.A. , Katerberg B.J. , Steiger J.A.
Published: June 2007

Yttria‐stabilized zirconia ceramic (Y‐TZP) has been used in total hip arthroplasty for many years but is susceptible to low‐temperature aging. Medical‐grade magnesia‐stabilized zirconia (Mg‐PSZ) is less commonly used; however, it has been shown to resist phase transformation. The purpose of this study was to directly compare the effects of artificial aging on phase transformation, surface roughness, and Vickers microhardness on Y‐TZP and Mg‐PSZ femoral heads. Y‐TZP and Mg‐PSZ heads were artificially aged in an autoclave in stages up to a total of 49 h. The surface roughness of Y‐TZP significantly increased with each stage of artificial aging. Y‐TZP heads aged for 49 h had a significantly higher monoclinic phase concentration and roughness, and a significantly lower microhardness, than nonaged Y‐TZP heads. Artificial aging also caused the surface of Y‐TZP to exhibit a lumpy “orange peel”‐like appearance with a significantly higher mean peak height, suggesting that artificial aging causes individual grains to be pushed out of the surface. In contrast, artificial aging did not significantly affect the properties of Mg‐PSZ heads. These findings suggest that Mg‐PSZ is a satisfactory material for orthopaedic implant use, while Y‐TZP, in the form tested, is not adequately stable for use as a bearing surface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Mirk/Dyrk1B in cancer
Authors: Friedman Eileen
Published: June 2007

Mirk/Dyrk1B is a member of a conserved family of serine/threonine kinases which are activated by intramolecular tyrosine phosphorylation, and which mediate differentiation in different tissues—Mirk in skeletal muscle, Dyrk1A in the brain, etc. One role of Mirk in skeletal muscle differentiation is to block cycling myoblasts in the G0 quiescent state by modification of cell cycle regulators, while another role of Mirk is to limit apoptosis in fusing myoblasts. Amplification of the Mirk gene, upregulation of Mirk expression and/or constitutive activation of this kinase have been observed in several different types of cancer. If coupled with a stress condition such as serum starvation which induces a quiescent state, depletion of Mirk by RNA interference using either synthetic duplex RNAi's or pSilencer‐encoded RNAi's have decreased colony formation of different cancer cell lines and enhanced apoptosis induced by chemotherapeutic drugs. Mirk is activated by phosphorylation by the stress‐activated SAPK kinases MKK3 and MKK6. Our working hypothesis is that Mirk is activated by this pathway in response to various stresses, and then acts as a checkpoint kinase to arrest damaged tumor cells in a quiescent state and allow cellular repair. Pharmacological inhibition of Mirk may enhance the anti‐tumor effect of chemotherapeutic drugs. J. Cell. Biochem. 102: 274–279, 2007. © 2007 Wiley‐Liss, Inc.
US‐guided percutaneous needle biopsy of the spleen using 18‐gauge versus 21‐gauge needles
Authors: Liang Ping , Gao Yangyan , Wang Yang , Yu Xiaoling , Yu Dejiang , Dong Baowei
Published: June 2007

Purpose

To compare the techniques of sonographically (US)‐guided percutaneous needle biopsy of the spleen using 18‐gauge and 21‐gauge needles.

Methods

Forty‐two patients undergoing 43 spleen biopsy procedures for focal lesions (n = 27 [16 single, 11 multiple]) or diffuse splenomegaly (n = 15) were analyzed. Two groups were divided randomly according to needle type: group 1 comprised 25 patients biopsied with an 18‐gauge cutting needle for histologic examination; group 2 comprised 17 patients biopsied with a 21‐gauge needle for histologic and cytologic examinations. Diagnostic accuracy, complication rate, and number of needle passes were compared between the 2 groups.

Results

Correct histopathologic diagnosis was obtained in 36 cases, whereas incorrect diagnosis occurred in 6 cases. The accuracy of US‐guided spleen biopsy in this series was 85.7%, with 1 patient (2.4%) having postprocedural hemorrhage. Compared with the 21‐gauge needle, the 18‐gauge needle had higher diagnostic accuracy (P < 0.05), required fewer needle passes (P < 0.05), and there was no significant difference in overall complication rate.

Conclusion

Because biopsy with an 18‐gauge needle yields larger and unfragmented samples with higher diagnostic rate compared with a 21‐gauge needle, and no increased rate of major complication requiring surgical intervention, it may be advantageous to use an 18‐gauge cutting needle in the US‐guided needle biopsy of splenic lesions. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Deconstructing the pharyngeal metamere
Authors: Graham Anthony
Published: June 2007

A prominent feature of all vertebrate embryos is the presence of a series of bulges on the lateral surface of the head, the pharyngeal arches. These structures constitute a metameric series, with each arch forming a similar set of derivatives. Significantly, the development of the pharyngeal arches is complex as it involves interactions between disparate embryonic cell types: ectoderm, endoderm, mesoderm and neural crest. It is becoming increasingly apparent that the development of the pharyngeal metamere revolves around the pharyngeal endoderm. The segmentation of this tissue is central to the generation of the arches. The pharyngeal endoderm also provides positional cues for the neural crest, and is involved in the induction of a number of components of the pharyngeal metamere. The segmentation of the pharyngeal endoderm has also been key to the evolution of pharyngeal metamerism. It is likely that endodermal segmentation is a deuterostome characteristic and that this basic pattern was sequentially modified and over time the more complex pharyngeal metamere of vertebrates emerged. J. Exp. Zool. (Mol. Dev. Evol.) 310B:336–344, 2008. © 2007 Wiley‐Liss, Inc.
The synthesis of dopaminergic radioligands labelled with tritium and iodine‐125
Authors: Filer Crist N.
Published: June 2007

The preparation of dopaminergic ligands radiolabelled with either tritium or iodine‐125 has been an extremely important undertaking to advance understanding of this critical receptor class and the topic is reviewed from 1976 through 2006. Although not an exhaustive compilation of references, the cited examples highlight the many methods employed to prepare these useful reagents. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐term effects on the digestive tract of feeding large amounts of resistant starch: A study in pigs
Authors: Martínez‐Puig Daniel , Castillo Marisol , Nofrarias Miquel , Creus Eva , Pérez José F
Published: June 2007

The present study aimed to assess the digestive consequences of the long‐term intake of two starches providing different amounts of resistant starch. Growing pigs were used as the animal model and meal‐fed for 14 weeks on a diet containing a high amount of either raw potato starch (RPS) or corn starch (CS). Digestive adaptation was chronologically evaluated by measuring organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and starch digestibility. After 97 days, whole‐tract digestibility of OM, CP and NDF was lower for RPS‐ compared to CS‐fed pigs, whereas no differences were observed in faecal starch digestibility. In contrast, starch digestibility was reduced in the proximal compartments (ileum, caecum and proximal colon) of animals fed the RPS diet. The concentration of short‐chain fatty acids (SCFAs; P < 0.05), and purine bases (PBs; P < 0.01) was also higher in distal colon and rectum of animals fed the RPS diet. Changes in bacterial community structure (dendogram analyses) were seen in the rectum. Biodiversity tends to increase more in RPS compared to CS fed animals (34.1 vs. 28.8; P = 0.07). Among SCFAs, the proportion of butyrate was two‐fold higher in proximal colon digesta of RPS compared to CS fed pigs (0.20 vs. 0.11; P < 0.05). Increased butyrate formation in the colon reduced the number of apoptosis per crypt in the proximal colonic mucosa (0.38 vs. 0.62; P < 0.05). RPS fermentation reduced indices associated with damage to intestinal epithelial cells, such as crypt cell hyperproliferation and magnesium excretion. Long‐term ingestion of RPS induces pronounced changes of the digestive tract and their microflora, modifying mineral absorption and colonic morphology for which health benefits are likely to be associated. Copyright © 2007 Society of Chemical Industry
The role of mass spectrometry to study the Oklo–Bangombé natural reactors
Authors: De Laeter J.R. , Hidaka H.
Published: June 2007

The discovery of the existence of chain reactions at the Oklo natural reactors in Gabon, Central Africa in 1972 was a triumph for the accuracy of mass spectrometric measurements, in that a 0.5% anomaly in the 235U/238U ratio of certain U ore samples indicated a depletion in 235U. Mass spectrometric techniques thereafter played a dominant role in determining the nuclear parameters of the reactor zones themselves, and in deciphering the geochemical characteristics of various elements in the U‐rich ore and in the surrounding rock strata. The variations in the isotopic composition of a large number of elements, caused by a combination of nuclear fission, neutron capture and radioactive decay, provide a powerful tool for investigating this unique geological environment. Mass spectrometry can be used to measure the present‐day elemental and isotopic abundances of numerous elements, so as to decipher the past history of the reactors and examine the retentivity/mobility of these elements. Many of the fission products have a radioactive decay history that have been used to date the age and duration of the reactor zones, and to provide insight into their nuclear and geochemical behavior as a function of time. The Oklo fission reactors and their near neighbor at Bangombé, some 30 km to the south‐east of Oklo, are unique in that not only did they become critical some 2 × 109 years ago, but also the deposits have been preserved over this period of geological time. The long‐term geochemical behavior of actinides and fission products have been extensively studied by a variety of mass spectrometric techniques over the past 30 years to provide us with significant information on the mobility/retentivity of this material in a natural geological repository. The Oklo–Bangombé natural reactors are therefore geological analogs that can be evaluated in terms of possible radioactive waste containment sites. As more reactor zones were discovered, it was realized that they could be classified into two groups according to their burial depth in the Oklo mine‐site. Reactor Zones 10, 13, and 16 were buried more deeply, and were therefore less weathered than the other zones. The less‐weathered zones are of great importance in mobility/retentivity studies and therefore to the question of radioactive waste containment. Isotopic studies of these natural reactors are also of value in physics to examine possible variations in fundamental constants over the past 2 billion years. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:683–712, 2007
Protein kinase Cε interacts with Stat3 and regulates its activation that is essential for the development of skin cancer
Authors: Aziz Moammir H. , Manoharan Herbert T. , Sand Jordan M. , Verma Ajit K.
Published: June 2007

Protein kinase C (PKC) represents a large family of phosphatidylserine (PS)‐dependent serine/threonine protein kinases. At least six PKC isoforms (α, δ, ε, η, µ, and ζ) are expressed in epidermis. PKC is a major intracellular receptor for 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) and is also activated by a variety of stress factors including ultraviolet radiation (UVR). PKC isozymes (α, δ, ε, and η), exhibit specificities to the development of skin cancer. PKCε, a calcium‐insensitive PKC isoform, is linked to the development of squamous cell carcinoma (SCC) elicited either by the 7,12‐Dimethylbenzanthracene (DMBA)‐TPA protocol or by repeated exposures to UVR. PKCε overexpressing transgenic mice, when treated either with TPA or exposed to UVR, elicit similar responses such as inhibition of apoptosis, promotion of cell survival, and development of SCC. PKCε overexpression increases Stat3 activation after either TPA treatment or UVR exposure. Both PKCε and signal transducers and activators of transcription‐3 (Stat3) are implicated in the development of SCC. However, the link between PKCε and Stat3 remains elusive. We found that PKCε interacts with Stat3. PKCε interaction with Stat3 was dependent upon UVR treatment. In reciprocal immunoprecipitation/blotting experiments, Stat3 coimmunoprecipitated with PKCε. Colocalization of PKCε with Stat3 was confirmed by double immunofluorescence staining. PKCε interaction with Stat3 was PKCε isoform specific and was not observed with other protein kinases. As observed in vitro with immunocomplex kinase assay with immunopurified PKCε and Stat3, PKCε phosphorylated Stat3 at the serine 727 residue. PKCε depletion prevented Stat3Ser727 phosphorylation, Stat3 DNA binding, and transcriptional activity. The results presented indicate that PKCε mediates Stat3 activation. © 2007 Wiley‐Liss, Inc.
Costly price adjustment and the optimal rate of inflation
Authors: Konieczny Jerzy D.
Published: June 2007

I analyse the optimal rate of inflation when prices are costly to change. As the costs of price adjustment are the main friction in the model, effects of inflation stem from the accounting role of money. Inflation increases relative price variability and reduces the average product of labour. This productivity distortion may be offset by a reduction in the desired real price. In general, the optimal rate of inflation is zero. This is consistent with early studies in monetary literature (LeBlanc, 1690, Jevons, 1875, Fisher, 1911 and Marshall, 1923), which concentrated on the role of money as a unit of account and argued that the goal of monetary policy should be price stability. Copyright © 2007 John Wiley & Sons, Ltd.
An implicit unitless error and step‐size control method in integrating unified viscoplastic/creep ODE‐type constitutive equations
Authors: Cao J. , Lin J. , Dean T. A.
Published: June 2007

A series of numerical analyses are carried out to investigate the difficulties in numerical integration of unified viscoplastic/creep constitutive equations, which are normally represented as a system of ordinary differential equations (ODEs). The problems of numerically integrating the constitutive equations are identified and analysed. To overcome the stiffness problems, implicit methods are used for the numerical integration and a generic technique is introduced to calculate the Jacobian matrix. A normalization technique is introduced in the paper to convert the integration errors for each time increment to unitless errors. Thus, a single tolerance can be used to control the accuracy and step size in integrating a set of unified viscoplastic/creep constitutive equations. In addition, an implicit
step‐size control method is proposed and used in the integrations. This method reduces the possibility of rejection of an integration increment due to poor accuracy. Copyright © 2007 John Wiley & Sons, Ltd.
Occlusal grooves in anterior dentition among Kovuklukaya inhabitants (Sinop, northern Anatolia, 10th century AD)
Authors: Erdal Y. S.
Published: June 2007

Mesiodistally directed grooves have been observed on the occlusal surfaces of nine incisors of five females in a small skeletal population from Kovuklukaya (Sinop, northern Anatolia, 10th century AD). There is no archaeological evidence to explain the cultural practices that must have caused such unusual abrasions of the anterior dentition. Investigations of the geographical characteristics of the region and data gathered on the traditional lifestyles of Çulhalı inhabitants enables us to reach meaningful conclusions about the Kovuklukaya people. According to the direction of the grooves, ecological characteristics of the region, and ethnographic data, it is proposed that the unusual abrasion observed in the Kovuklukaya population may be linked to passing yarn between the anterior teeth to wet it. The grooves in the Kovuklukaya population were found only in female skeletons, indicating the existence of a sex‐based division of labour in yarn production. Copyright © 2007 John Wiley & Sons, Ltd.
Blood–retinal barrier disruption and ultrastructural changes in the hypoxic retina in adult rats: the beneficial effect of melatonin administration
Authors: Kaur C , Sivakumar V , Yong Z , Lu J , Foulds WS , Ling EA
Published: June 2007

Reactive changes in astrocytes and Müller cells in the retina of adult rats subjected to hypoxia were investigated. Along with this, the integrity of the blood–retinal barrier (BRB) was assessed using fluorescent and electron‐dense tracers. In hypoxic rats, mRNA and protein expression of glial fibrillary acidic protein (GFAP) and aquaporin‐4 (AQ4) were significantly increased. AQ4 immunoreactive cells were identified as astrocytes and Müller cells by double immunofluorescence labelling. Another alteration in the hypoxic retina was marked reduction in melatonin content compared to controls. In this connection, administration of exogenous melatonin reduced the tissue concentration of vascular endothelial growth factor (VEGF) and nitric oxide (NO); both were elevated in hypoxic rats. A major structural change in the hypoxic retina was swelling of astrocyte and Müller cell processes but this was noticeably attenuated after melatonin administration. Following an intraperitoneal or intravenous injection of rhodamine isothiocyanate (RhIC) or horseradish peroxidase (HRP), leakage of both tracers was observed in the retina in hypoxic rats but not in the controls, indicating that the functional integrity of the BRB is compromised in hypoxia/reoxygenation. It is suggested that enhanced tissue concentration of VEGF and NO production in the hypoxic retina contribute to increased permeability of the retinal blood vessels. The concurrent up‐regulation of AQ4, a water‐transporting protein, in astrocytes and Müller cells in hypoxia suggests its involvement in oedema formation. Since melatonin effectively reduced the vascular permeability in the retina of hypoxic rats, as evidenced by reduced leakage of RhIC, we suggest that its administration may be of potential benefit in the management of retinal oedema associated with retinal hypoxia. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Treatment of metastatic Ewing sarcoma/primitive neuroectodermal tumor of bone: Evaluation of increasing the dose intensity of chemotherapy—a report from the Children's Oncology Group
Authors: Miser James S. , Goldsby Robert E. , Chen Zhengjia , Krailo Mark D. , Tarbell Nancy J. , Link Michael P. , Fryer Christopher J.H. , Pritchard Douglas J. , Gebhardt Mark C. , Dickman Paul S. , Perlman Elizabeth J. , Meyers Paul A. , Donaldson Sarah S. , Moore Sheila G. , Rausen Aaron R. , Vietti Teresa J. , Grier Holcombe E.
Published: June 2007

Background

The outcome for patients with Ewing sarcoma family of tumors (ESFTs) of bone with metastases at diagnosis remains poor despite new approaches to treatment. We evaluated whether a dose‐intensity chemotherapy regimen improved survival for patients with ESFTs of bone with metastases at diagnosis.

Methods

We entered 60 patients with metastatic ESFTs of bone onto a single arm trial of a new intensive therapy. Treatment consisted of 51‐weeks of chemotherapy and local control of the primary with radiation, surgery, or both. The chemotherapeutic protocol included two alternating blocks: one with vincristine (2 mg/m2), doxorubicin (90 mg/m2), and cyclophosphamide (2,200 mg/m2); and the second with ifosfamide (2,800 mg/m2/day × 5 days) and etoposide (100 mg/m2/day × 5 days).

Results

Of the 60 patients with metastatic ESFTs of bone enrolled onto this single arm trial, 12 had metastasis to lung only, 7 to bone marrow or bone only, 38 to multiple sites, 2 in other sites and 3 not specified. There were three toxic deaths. Six patients (6‐year cumulative incidence: 9%) developed second malignant neoplasms and died. The 6‐year overall event‐free survival (EFS) was 28% (standard error (SE) 6%) and survival (S) was 29% (SE 6%).

Conclusion

An intensified treatment regimen using higher doses of cyclophosphamide, ifosfamide, and doxorubicin increased toxicity and risk of second malignancy without improving EFS and S. Pediatr Blood Cancer 2007;49:894–900. © 2007 Wiley‐Liss, Inc.
Synthesis of stable “gold nanoparticle–polymeric micelle” conjugates: A new class of star “molecular chimera” that self‐assemble into linear arrays of spherical micelles
Authors: Abraham Sinoj , Ha Chang‐Sik , Batt Carl A. , Kim Il
Published: June 2007

Stable and aggregation‐free “gold nanoparticle–polymeric micelle” conjugates were prepared using a new and simple protocol enabled by the hydrogen bonding between surface‐capping ligands and polymeric micelles. Individual gold nanoparticles were initially capped using a phosphatidylthio–ethanol lipid and further conjugated with a star poly(styrene‐block‐glutamic acid) copolymer micelle using a one‐pot preparation method. The morphology and stability of these gold–polymer conjugates were characterized using transmission electron microscopy (TEM) and UV–vis spectroscopy. The self‐assembly of this class of polymer‐b‐polypeptide in aqueous an medium to form spherical micelles and further their intermicelle reorganization to form necklace‐like chains was also investigated. TEM and laser light scattering techniques were employed to study the morphology and size of these micelles. Polymeric micelles were formed with diameters in the range of 65–75 nm, and supermicellular patterns were observed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3570–3579, 2007
Polymerization of 1‐olefins by zirconium/titanium precatalysts with O,N,O‐ligating atoms—can aggregation of catalyst be inferred from the reaction profile?
Authors: Keren Everta , Sundararajan Govindarajan
Published: June 2007

The 2‐[benzyl‐(2‐hydroxy‐2‐phenylethyl)‐amino]‐1‐phenylethanol ligand (1‐H2) prepared as a diastereomeric mixture or in racemic and meso forms, from known procedure, has been disodiated and complexed with ZrCl4. The precatalysts (mix‐1‐ZrCl2, rac‐1‐ZrCl2, and meso‐1‐ZrCl2) were used in combination with methylaluminoxane and found to be active for the polymerization of 1‐hexene and 1‐octene. The high molecular weight polyhexenes (PHs) and polyoctenes (POs) thus obtained were isotactic in nature and showed a negligible amount of end groups arising from the chain termination reactions. In PHs and POs, there was linear correlation in the modified Arrhenius plot (the natural logarithm of the number‐average molecular weight vs. the reciprocal of the temperature), indicating the presence of a single active species. The enantiomerically pure titanium precatalyst ((R,R)‐1‐TiCl2), when employed for the polymerization of 1‐hexene, was found to be active and the modified Arrhenius plot showed linear dependence demonstrating presence of a single active species. The analogous titanium precatalysts (mix‐1‐TiCl2, rac‐1‐TiCl2, and meso‐1‐TiCl2) obtained from known procedures were also found to be active for the polymerization of 1‐octene. The rac‐1‐TiCl2 precatalyst demonstrated a sigmoidal behavior in the modified Arrhenius plot for the POs and the mix‐1‐TiCl2 precatalyst showed an exponential type of behavior. The obtained POs seemed to have small amounts of chain termination via β‐hydride elimination alone. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3599–3610, 2007
A novel synthetic strategy for copolymers of vinyl alcohol: Radical copolymerization of alkoxyvinylsilanes with styrene and oxidative transformation of CSi(OR)2Me into COH in the copolymers to afford poly(vinyl alcohol‐ran‐styrene)s
Authors: Ihara Eiji , Kurokawa Atsushi , Itoh Tomomichi , Inoue Kenzo
Published: June 2007

As a novel synthetic strategy for copolymers of vinyl alcohol, we propose herein copolymerization of alkoxyvinylsilanes with other vinyl monomers, followed by oxidative cleavage of the alkoxysilyl groups attached to the main chain of the resulting copolymers. Radical copolymerization of di(isobutoxy)methylvinylsilane 1 with styrene afforded poly(1‐ran‐styrene)s with a variety of compositions of both repeating units, although the Mn's (<9000) and yields (<35%) were rather low. The oxidative cleavage of the alkoxysilyl groups in the copolymers with m‐chloroperbenzoic acid proceeded efficiently, giving poly(vinyl alcohol‐ran‐styrene)s, which were soluble in common organic solvents. The structures of the poly(vinyl alcohol‐ran‐styrene)s were characterized by NMR, GPC, elemental analysis, and matrix‐assisted laser desorption time‐of‐flight mass spectrometry (MALDI‐TOF‐MS). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3648–3658, 2007
Gas‐Solid Flow in a Two‐Dimensional Cross‐Flow Moving Granular Filter Bed with a Symmetric Boundary
Authors: Chou Chuen‐Shii , Lee Ang‐Fen , Yeh Chun‐Hung
Published: June 2007

This study investigates how the inlet gas velocity and the louver angle affect the granular flow of spherical particles in two‐dimensional moving (and fixed) granular filter beds with a symmetric louvered‐wall. The methodology of Tsuji et al. [1] was extended to facilitate this gas‐solid flow field calculation. The calculation procedures were as follows: (1) determination of the coordinates of each spherical particle and calculation of the void fraction of the granular bed; (2) calculation of the updated two‐dimensional gas velocity field using the SIMPLE method [2]; (3) determination of the drag force acting on the particle using the equation of Fan and Zhu [3], and (4) obtaining the contact force, velocity and displacement of each particle using the DEM model devised by Cundall and Starck [4]. In addition, a digital camcorder was used to record the flow pattern histories of the spherical particles in cross‐flow moving (and fixed) granular filter beds with a symmetric louvered‐wall. The numerical predictions were compared with the experimental results in a qualitative manner. In a fixed granular bed, the bubble area obtained, which is based on numerical predictions agrees with that obtained experimentally, and increases with louver angle. However, in a moving granular bed, the bubble area obtained by numerical modeling increases with louver angle, but the bubble area obtained experimentally decreases with increasing louver angle. Additionally, this investigation demonstrates both numerically and experimentally that the bubble area increases with air inlet velocity in both fixed and moving granular beds.