bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of novel thermal sprayed antibacterial coating and evaluation of release properties of silver ions
Authors: Noda Iwao , Miyaji Fumiaki , Ando Yoshiki , Miyamoto Hiroshi , Shimazaki Takafumi , Yonekura Yutaka , Miyazaki Masaki , Mawatari Masaaki , Hotokebuchi Takao
Published: October 2008

Several studies have addressed the use of antibacterial coating to reduce implant‐associated infections. In this study, novel silver (Ag)‐containing calcium‐phosphate (CP) coating technology based on the thermal spraying method was developed. The coating's physical and chemical properties, in vitro antibacterial activity, hydroxyapatite (HA)‐forming ability, and release of Ag ions were evaluated. An amorphous structure of the coating was confirmed by X‐ray diffraction, and Ag residue in the coating was determined by elementary analysis. The coating showed strong antibacterial activity to methicillin‐resistant Staphylococcus aureus in fetal bovine serum (FBS) along with HA‐forming ability in simulated body fluid. Therefore, it is expected that the coating would confer antibacterial and bone bonding abilities to the implant surface. Time course release testing of Ag ions from the coating on immersion in FBS showed pronounced Ag release for up to 24 h after immersion, with consistent strong antibacterial activity at the early postoperative stage. In repeated testing, the amount of released Ag ions was about 6500 parts per billion (ppb, μg/L) for the first release test, after which it gradually decreased. However, retention of significant release of Ag ions after a sixth repeat implies that Ag release from the coating is slow in FBS. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The use of brushite calcium phosphate cement for enhancement of bone‐tendon integration in an anterior cruciate ligament reconstruction rabbit model
Authors: Wen Chun‐Yi , Qin Ling , Lee Kwong‐Man , Chan Kai‐Ming
Published: October 2008

This study was designed to investigate the osteoconductivity and bioresorption of brushite calcium phosphate cement (CPC) in bone‐tendon interface healing after anterior cruciate ligament (ACL) reconstruction. Surgical reconstruction using grafted tendon in bone tunnel was performed bilaterally in 28 skeletal mature rabbits. Brushite CPC was implanted between grafted tendon and bone tunnel of one limb with the contralateral one as the control. A batch of 14 rabbits was sacrificed at 6 and 12 weeks, respectively, after surgery. At each time point, six rabbits were used for micro‐CT and subsequent histological examinations, whereas the remaining eight rabbits were used for pull‐out testing. The components of brushite CPC‐dicalcium phosphate dihydrate matrix degraded rapidly with β‐tricalcium phosphate granules left for guiding new bone formation. Brushite CPC augmented the peri‐tendon bone volume and promoted bone growth into the healing interface. The ultimate strength and stiffness of the graft‐tunnel complexes on experimental side was higher than that of the control by 117% and 102%, respectively, at 6 weeks postoperatively (p < 0.05 for both). The use of brushite CPC caused a paradigm shift in failure mode from intra‐tunnel to intra‐articular portion at 12 weeks postoperatively (p = 0.013). Brushite CPC significantly enhanced the bone‐tendon integration after ACL reconstruction, which provided a scientific basis for clinical application. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Preparation and characterization of novel biphasic calcium phosphate powders (α‐TCP/HA) derived from carbonated amorphous calcium phosphates
Authors: Li Yanbao , Kong Fanzhi , Weng Wenjian
Published: October 2008

Novel biphasic calcium phosphate (BCP) powders composed of α‐tricalcium phosphate (α‐TCP) and hydroxyapatite (HA) were prepared by thermal decomposition of carbonated amorphous calcium phosphates (CACP). At first, the CACP precipitates were synthesized by adding ammonium carbonate in the presence of poly(ethylene glycol) at pH 10 with an initial Ca/P molar ratio of 1.60 at 5°C. The Ca/P molar ratios of the CACP precursors are between 1.50 and 1.67 investigated by ICP. Then BCP (α‐TCP/HA) powders were obtained after heating the CACP precursors at relatively low temperature (800°C) for 3 h. α‐TCP/HA powders were characterized by X‐ray diffractometry, Fourier transform infrared spectra, transmission electron microscopy/scanning electron microscopy, and sedimentation experiment. The results show that α‐TCP and HA phases form in one powder, α‐TCP/HA powders are sphere with the diameter of 300 nm to less than 100 nm varied with their chemical compositions and the ratio of α‐TCP and HA in the powders can be adjusted by the adding amount of carbonates. The possible formation process of biphasic α‐TCP/HA powders was proposed. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Revisiting the greed and grievance explanations for violent internal conflict
Authors: Murshed Syed Mansoob , Tadjoeddin Mohammad Zulfan
Published: October 2008

Two phenomena have been recently utilised to explain conflict onset among rational choice analysts: greed and grievance. The former reflects elite competition over valuable natural resource rents. The latter argues that relative deprivation and the grievance it produces fuels conflict. Neither the presence of greed or grievance issufficientfor the outbreak of violent conflict, something which requires institutional breakdown, which we describe as the failure of the social contract. The degradation of the social contract is more likely in the context of poverty and growth failure. We provide a synthesis of the greed and grievance hypotheses. Copyright © 2008 John Wiley & Sons, Ltd.
Symmetry variation in the heart‐descending artery system of the parthenogenetic marbled crayfish
Authors: Vogt Günter , Wirkner Christian S. , Richter Stefan
Published: October 2008

The internal anatomy of freshwater crayfish is strictly bilaterally symmetric, with the conspicuous exception of the vertically oriented descending artery (sternal artery), which originates from the heart and terminates in the subneural artery. Serial sectioning of 133 juveniles of the parthenogenetic marbled crayfish revealed that the descending artery was bilaterally symmetric in 4.5% of the specimens, right asymmetric in 45.1%, and left asymmetric in 50.4%. In the bilaterally symmetric variant two branches arise from the left and right chambers of the bulbus of the heart, run laterally around the hindgut, and fuse underneath it. The asymmetric variants have only one dorsal branch, which loops around the hindgut on either the left or the right side. Other structures of the heart, such as the paired antennary and hepatopancreatic arteries and the ostia or the unpaired anterior and posterior aortae, showed no symmetry variation. Because of the genetic identity of the experimental animals and their culture under identical environmental conditions, the variation in symmetry of the descending artery observed is interpreted as the result of developmental variation. We recommend that the marbled crayfish be considered for investigation of the epigenetic mechanisms responsible for the maintenance and breaking of bilateral symmetry in metazoans. J. Morphol., 2009. © 2008 Wiley‐Liss, Inc.
A high‐order discontinuous Galerkin method with time‐accurate local time stepping for the Maxwell equations
Authors: Taube Arne , Dumbser Michael , Munz Claus‐Dieter , Schneider Rudolf
Published: October 2008

We present an explicit numerical method to solve the time‐dependent Maxwell equations with arbitrary high order of accuracy in space and time on three‐dimensional unstructured tetrahedral meshes. The method is based on the discontinuous Galerkin finite element approach, which allows for discontinuities at grid cell interfaces. The computation of the flux between the grid cells is based on the solution of generalized Riemann problems, which provides simultaneously a high‐order accurate approximation in space and time. Within our approach, we expand the solution in a Taylor series in time, where subsequently the Cauchy–Kovalevskaya procedure is used to replace the time derivatives in this series by space derivatives. The numerical solution can thus be advanced in time in one single step with high order and does not need any intermediate stages, as needed, e.g. in classical Runge–Kutta‐type schemes. This locality in space and time allows the introduction of time‐accurate local time stepping (LTS) for unsteady wave propagation. Each grid cell is updated with its individual and optimal time step, as given by the local Courant stability criterion. On the basis of a numerical convergence study we show that the proposed LTS scheme provides high order of accuracy in space and time on unstructured tetrahedral meshes. The application to a well‐acknowledged test case and comparisons with analytical reference solutions confirm the performance of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.
The industry settings of leading organizational research: the role of economic and non‐economic factors
Authors: O'Leary Michael Boyer , Almond Bradley A.
Published: October 2008

Despite calls for attention to the role of context in organizational research, there have been no assessments of the distribution of industry contexts in organizational research. This paper explores that distribution in relation to the industry composition of the U.S. economy. Our analysis of 914 empirical field studies published in four leading journals from 1988 to 2002 reveals striking, persistent, and growing discrepancies between the industries that are economically important and the industries that have served as settings for organizational research. For example, education and manufacturing are oversampled in relation to their economic importance, while real estate, construction, wholesale, and retail are undersampled. We also develop and test a series of hypotheses predicting which industries serve as the contexts for leading research. Using negative binomial regression, we show that the percentage of recent MBA graduates in an industry and the percentage of employees with doctoral degrees in an industry predict the number of articles set in that industry, with the total number of employees and average establishment size in an industry enhancing the power of the model. We conclude by discussing the implications of our findings for advancing organizational theory and research methods. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of chemical species of fluorescein isothiocyanate isomer–I (FITC) monolayers on platinum by doubly resonant sum‐frequency generation spectroscopy
Authors: Maeda Toshiki , Nagahara Tetsuhiko , Aida Misako , Ishibashi Taka‐aki
Published: October 2008

Doubly resonant sum‐frequency generation (DR‐SFG) spectroscopy of fluorescein‐4‐isothiocyanate isomer‐I (FITC) monolayers on platinum was performed. Vibrational spectra of the monolayers for the IR wavenumber of 1750–1450 cm−1 were measured with visible probes ranging from 431 to 582 nm. Two vibrational bands at 1643 and 1610 cm−1 were observed, and their DR‐SFG excitation profiles displayed different shapes. By rinsing the monolayers with an alkaline solution, the smaller wavenumber band disappeared and the larger wavenumber band gained intensity. On the basis of the spectral response to the rinsing, we concluded that the FITC molecules existed on platinum as deprotonated and protonated forms; the former corresponds to the 1643 cm−1 band and the latter to the 1610 cm−1 band. The deprotonated form was assigned to an anionic surface species, and the protonated form to a neutral surface species by comparing the DR‐SFG excitation profiles with electronic absorption spectra of the protolytic forms of fluorescein in an aqueous solution (Sjöback R et al., Spectrochimica Acta A 1995; 51: L7–L21). The results demonstrate that the measurement of DR‐SFG excitation profiles is a useful technique to identify chemical species of monolayers on metal surfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Spatially resolved Raman investigation on phase separations of mixed Na2SO4/MgSO4 droplets
Authors: Dong Jin‐Ling , Xiao Han‐Shuang , Zhao Li‐Jun , Zhang Yun‐Hong
Published: October 2008

By using spatially resolved Raman spectroscopy together with in situ microscopy, mixed Na2SO4/MgSO4 aerosol particles with molar ratios of 1:1 and 2:1 deposited on a quartz substrate were carefully examined in their evaporation processes. Upon decreasing the relative humidity (RH), phase separations were found to occur for these droplets. For Na2SO4/MgSO4 droplets with a molar ratio of 1:1, two paths of phase separation were identified, and a large amount of small crystals were observed to disorderly distribute in the residual solutions. By comparisons with the known Raman spectra of crystals, it was concluded that the scattered crystals in the two paths were anhydrous Na2SO4 in metastable phase III and the double salt of Na2SO4· MgSO4 · 4H2O, respectively. For Na2SO4/MgSO4 aerosol droplets with a molar ratio of 2:1, only anhydrous Na2SO4 in metastable phase III precipitated with the decrease of RH. Copyright © 2008 John Wiley & Sons, Ltd.
Rotational disorder in 2‐piperidyl‐5‐nitro‐6 ‐methylpyridine: structural phase transition and its vibrational characteristics
Authors: Lorenc J. , Palasek B. , Hanuza J. , Mączka M. , Waśkowska A.
Published: October 2008

X‐ray diffraction (XRD) studies have shown that 2‐piperidyl‐5‐nitro‐6‐methylpyridine, C11H15N3O2, undergoes a structural phase transition at T = 240 K. The room temperature structure is tetragonal, space group I41/a, with the unit‐cell dimensions a = 13.993(2) and c = 23.585(5) Å. The pyridine ring takes trans conformation with respect to the piperidine unit. While pyridine is well ordered, the piperidine moiety shows apparent disorder resulting from a libration about the linking NC bond. The low‐temperature phase is monoclinic, space group I2/a. Contraction of the unit‐cell volume by 2.3% at 170 K enables the CH···O linkage between the molecules of the neighbouring stacks. As result, the asymmetric unit becomes bi‐molecular. The thermal librations of the piperidine and methyl groups become considerably reduced at 170 K and nearly fully reduced at about 100 K. The IR spectra and polarised Raman spectra agree with the X‐ray structure and confirm the disorder effect on the piperidine ring. The assignment of the bands observed was made on the basis of DFT chemical quantum calculations. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation on surface‐enhanced Raman scattering activity on an ex situ ORC roughened nickel electrode
Authors: Gu W. , Fan X. M. , Yao J. L. , Ren B. , Gu R. A. , Tian Z. Q.
Published: October 2008

Roughened nickel electrode surfaces have been demonstrated to exhibit a moderate enhanced Raman scattering effect with an enhancing factor of about 104, which is not suitable in some cases for further inhibition adsorbates study. We reported here a new modified roughening procedure of nickel electrodes, by which a high S/N ratio surface‐enhanced Raman spectroscopy (SERS) of pyridine was obtained. At least two major advantages were found for the modified roughening methods: (1) enhancing factor was improved by a factor of about 10, (2) SERS‐active sites were distributed uniformly on the Ni surfaces. Potential‐dependent SERS spectra of a candidate inhibitor molecule benzotriazole (BTAH) adsorbed onto nickel electrodes were briefly presented for verifying the feasibility of the modified roughening method in this paper. Results showed that BTAH molecules were adsorbed on the nickel electrodes in neutral molecule form at more negative potentials and a polymer‐like film with the composition of [Nin(BTA)p]m formed on the nickel electrodes with the positive shift of potentials. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopic study of the uranyl phosphate mineral dumontite Pb2 [(UO2)3O2(PO4)2]·5H2 O
Authors: Frost Ray L. , Čejka Jiří
Published: October 2008

Raman spectra of dumontite were measured at 298 and 77 K. Observed bands were attributed to the stretching and bending vibrations of uranyl and phosphate units and OH stretching vibrations of water molecules. U–O bond lengths in uranyls and approximate O–H···O bond lengths were calculated. The values of the U–O bond lengths are in agreement with the data from the single crystal structure analysis of dumontite. Copyright © 2008 John Wiley & Sons, Ltd.
Multiple primary tumors in men with breast cancer diagnoses—a SEER database review
Authors: Wernberg Jessica A. , Yap Johnny , Murekeyisoni Christine , Mashtare Terry , Wilding Gregory E. , Kulkarni Swati A.
Published: October 2008

Background

Male breast cancer (MBC) comprises 1% of all breast cancers and less than 1% of cancer cases in men. After a diagnosis of MBC, men are at risk of developing a second primary cancer, particularly a second primary breast cancer. The objective of this study is to analyze the characteristics of the population of men diagnosed with a second malignancy, specifically a second MBC.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) database, 4,873 male patients diagnosed with invasive or in situ breast cancer from 1973 to 2004 were identified and data from patients who developed a second MBC were reviewed. Additional non‐breast primary cancer diagnoses were also recorded.

Results

A review of 4,966 records corresponding to 4,873 patients revealed 4,462 invasive and 504 in situ breast cancer events. Of the 4,873 patients, 93 (1.9%) were identified with a second MBC. Among the 4,873 patients with MBC, 1,001 (21%) have other non‐breast primary cancer diagnoses recorded in the SEER registry.

Conclusions

Although MBC is uncommon, these patients are at risk of a contralateral breast cancer and second primary non‐breast cancers. Our findings support that men with breast cancer would benefit from continued long‐term surveillance for breast cancer and appropriate screening for non‐breast cancers. J. Surg. Oncol. 2009;99:16–19. © 2008 Wiley‐Liss, Inc.
Preoperative C‐reactive protein as a prognostic and therapeutic marker for colorectal cancer
Authors: Koike Yuhki , Miki Chikao , Okugawa Yoshinaga , Yokoe Takeshi , Toiyama Yuji , Tanaka Koji , Inoue Yasuhiro , Kusunoki Masato
Published: October 2008

Background and Objectives

This study aimed to evaluate the significance of preoperative C‐reactive protein (CRP) as a prognostic marker for carcinoembryonic antigen (CEA)‐independent stage I or II colorectal cancer (CRC) patients.

Methods

Preoperative CRP was measured in 300 CRC patients to assess its relationships with clinicopathological factors and long‐term survival. Based on the results of the initial study, the relationship between preoperative CRP and long‐term survival was evaluated with reference to adjuvant 5‐fluorouracil (5‐FU)‐based chemotherapy in a further 128 stage II patients.

Results

CRP was associated with disease progression and factors reflecting nutritional depletion such as serum albumin, lymphocyte count and body weight loss ratio. In stage I or II patients, CRP could predict early disease recurrence, even when a CEA test could not. Multivariate analyses revealed that CRP was an independent prognostic variable in stage I or II patients. In the additional 128 stage II patients, CRP‐positive patients showed a 3‐year survival rate of only 55% without adjuvant chemotherapy, but this increased to 90% with adjuvant chemotherapy.

Conclusions

CRP may be a potent prognostic and therapeutic indicator that provides valuable information for determining the need for adjuvant chemotherapy in stage II CRC patients. J. Surg. Oncol. 2008;98:540–544. © 2008 Wiley‐Liss, Inc.
Factors associated with anastomotic recurrence after total mesorectal excision in rectal cancer patients
Authors: Kim Young‐Wan , Kim Nam‐Kyu , Min Byung‐Soh , Huh Hyuk , Kim Jin‐Soo , Kim Jeong‐Yeon , Sohn Seung‐Kook , Cho Chang‐Hwan
Published: October 2008

Background

In patients undergoing total mesorectal excision (TME), the clinical variables most relevant to anastomotic recurrence have not been identified. We evaluated factors associated with anastomotic recurrence in patients undergoing TME and the impact of a reduced distal margin on anastomotic recurrence.

Methods

Thirty‐eight patients with anastomotic recurrence were compared with 876 patients who received curative rectal cancer surgery. Patients were compared according to: (1) the presence of anastomotic recurrence (recurrence vs. recurrence‐free), (2) distal margin length (≤10 mm vs. >10 mm) and (3) additional treatment (none, adjuvant, or neoadjuvant). The risk factors for anastomotic recurrence were analyzed.

Results

In the recurrence group, an advanced T stage (T3 and T4) (P = 0.01) microscopic distal margin involvement (P = 0.002) and an elevated CEA level (>5 ng/ml) (P = 0.04) were more commonly found. The incidence of anastomotic recurrence was not higher in the distal margin ≤10 mm group and did not differ according to additional treatment. The multivariate analysis showed that an advanced T stage (T3 and T4) and microscopic distal margin involvement were risk factors for anastomotic recurrence.

Conclusion

A distal margin ≤10 mm appears to be acceptable in terms of anastomotic recurrence. Patients with a positive distal margin, on the postoperative pathology, should be considered at high risk for anastomotic recurrence. J. Surg. Oncol. 2009;99:58–64. © 2008 Wiley‐Liss, Inc.
cAMP–Epac2‐mediated activation of Rap1 in developing male germ cells: RA‐RhoGAP as a possible direct down‐stream effector
Authors: Aivatiadou Evanthia , Ripolone Michela , Brunetti Francesco , Berruti Giovanna
Published: October 2008

Rap1 is a small GTPase that functions as a positional signal and organizer of cell architecture. Recently Rap1 is emerged to play a critical role during sperm differentiation since its inactivation in haploid cells leads to a premature release of spermatids from the supporting Sertoli cell resulting in male infertility. How Rap1 is activated in spermatogenic cells has not yet been determined. Our objective was to investigate on a possible cAMP‐mediated activation of Rap1 employing a cAMP analogue selective to Epac, the Rap1 activator directly responsive to cAMP, for stimulating cultured testis germ cells. Here we provide biochemical, cellular and functional evidence that the Epac variant known as Epac2 is expressed as both a transcript and a protein and that it is able to promote Rap1 activation in the cultured cells. A time course immunofluorescence analysis carried out on stimulated cells revealed the translocation of endogenous Epac2, which is cytosolic, towards the site where Rap1 is located, i.e., the Golgi complex, thus documenting the effective Rap1–Epac2 protein interaction ‘in vivo’ leading to Rap1‐GTP loading. A combination of biochemical and molecular techniques supported the immunofluorescence data. The search for the presence of a putative Rap1 downstream effector, described in differentiating somatic cells as a target of cAMP–Epac‐activated Rap1, revealed the presence in spermatogenic cells of RA‐RhoGAP, a Rap1‐activated Rho GTPase‐activating protein. Taken together, our results, obtained with endogenously expressed proteins, are consistent with a cAMP/Epac2/Rap1‐mediated signaling that could exert its action, among others, through RA‐RhoGAP to promote the progression of spermatogenesis. Mol. Reprod. Dev. 76: 407–416, 2009. © 2008 Wiley‐Liss, Inc.
Lanosterol metabolic product(s) is involved in primordial folliculogenesis and establishment of primordial folliclepool in mouse fetal ovary
Authors: Zhang Hua , Xu Baoshan , Xie Huirong , Zhou Bo , Ouyang Hong , Ning Gang , Li Ge , Zhang Meijia , Xia Guoliang
Published: October 2008

The primordial follicles present in neonatal ovary represent the fecundity of a female throughout her reproductive life. Germ cell meiosis and apoptosis are two important events during primordial folliculogenesis. In this study, through focusing on the cytochrome P450 lanosterol 14 alphademethylase (CYP51) and its lanosterol metabolic product(s), we explored the possible regulatory mechanism of the initiation of germ cell meiosis and primordial follicle formation. The expression of CYP51 could be detected in both oocytes and granulosa cells during primordial folliculogenesis by immunochemistry. RS21745, which leads to the reduction of lanosterol metabolic product(s) level, inhibited the primordial follicle formation in a dose‐dependent manner, and thus postpone the establishment of the primordial follicle pool when the mouse fetal ovaries were cultured in serum‐free medium. In contrast, the number of primordial follicle increased significantly with the accumulation of the lanosterol metabolic products caused by 0.025, 0.0625, and 0.125 µM AY9944‐A‐7 supplements. AY9944‐A‐7 also up‐regulated the expression of meiotic diplotene stage marker gene msy2 and primordial follicle formation regulatory gene fig‐alpha. Furthermore, AY9944‐A‐7 decreased the expression of apoptosis gene bax and significantly prevented oocyte apoptosis from 15.37 ± 1.97% to 3.68 ± 0.27% (P < 0.01) in neonatal ovary in vitro. In conclusion, our results indicate that lanosterol metabolic product(s) is involved in the primordial folliculogenesis by regulating the oocyte meiosis and apoptosis. Mol. Reprod. Dev. 76: 514–521, 2009. © 2008 Wiley‐Liss, Inc.
Consolidation around stone columns. Influence of column deformation
Authors: Castro Jorge , Sagaseta César
Published: October 2008

A solution is presented for the radial consolidation around stone columns under constant surcharge load. The solution considers the influence of vertical and radial deformation of the column, either in elastic and elastoplastic regimes.

The solution is in terms of the average excess pore pressure in the soil. It is based on previous solutions, initially developed for rigid column, or including only vertical deformation. For elastic column, the solution gives the variation of strains and stresses between the undrained and final states, for which it coincides with the existing elastic solutions.

All the results are given in closed form, and both the elastic and plastic deformations of the column lead to an equivalent coefficient of consolidation for the radial flow, which enables the application of the existing methods of integration of the consolidation equation.

A parametric study is presented, showing the influence of the main problem features. A design example is used to illustrate the application to practical cases. Copyright © 2008 John Wiley & Sons, Ltd.
Explicit expressions for 3D boundary integrals in potential theory
Authors: Nintcheu Fata S.
Published: October 2008

On employing isoparametric, piecewise linear shape functions over a flat triangular domain, exact expressions are derived for all surface potentials involved in the numerical solution of three‐dimensional singular and hyper‐singular boundary integral equations of potential theory. These formulae, which are valid for an arbitrary source point in space, are represented as analytic expressions over the edges of the integration triangle. They can be used to solve integral equations defined on polygonal boundaries via the collocation method or may be utilized as analytic expressions for the inner integrals in the Galerkin technique. In addition, the constant element approximation can be directly obtained with no extra effort. Sample problems solved by the collocation boundary element method for the Laplace equation are included to validate the proposed formulae. Published in 2008 by John Wiley & Sons, Ltd.
Synthesis of high‐molecular‐weight epoxy resins from modified natural oils and Bisphenol A or BisphenolA‐based epoxy resins
Authors: Czub Piotr
Published: October 2008

A method of synthesis of liquid high‐molecular‐weight epoxy resins from modified vegetable oils as natural raw materials is proposed. The possibility of application of epoxidized soybean, rapeseed, linseed, and sunflower oils as well as hydroxylated soybean and rapeseed oils as raw materials in the fusion process was verified. Reactions of: (i) epoxidized oils, used as low‐molecular‐weight epoxy resins, with Bisphenol A, as well as, (ii) Bisphenol A‐based epoxy resin with hydroxylated natural oils, were carried out in the presence of different catalysts (i.e., LiCl, 2‐methylimidazole, triphenylphosphine, and triethanolamine) in the temperature range of 130–160°C (depending on the catalyst type), and under nitrogen for minimization of the oxidative degradation. The epoxy value, color, number/weight‐average molecular weight, and polydispersity of the products obtained were studied in relation to the reaction conditions. Finally, the possibility of curing of the increased‐molecular‐weight epoxy resins, synthesized from the modified natural oils, with 2‐methylimidazole, dicyanodiamide, hexahydrophthalic anhydride, and triethylenetetramine was checked. The results of this research should enable reducing the use of petrochemical raw materials for the syntheses of high‐molecular‐weight epoxy resins. Copyright © 2008 John Wiley & Sons, Ltd.
Stem cell options for kidney disease
Authors: Hopkins C , Li J , Rae F , Little MH
Published: October 2008

Chronic kidney disease (CKD) is increasing at the rate of 6–8% per annum in the US alone. At present, dialysis and transplantation remain the only treatment options. However, there is hope that stem cells and regenerative medicine may provide additional regenerative options for kidney disease. Such new treatments might involve induction of repair using endogenous or exogenous stem cells or the reprogramming of the organ to reinitiate development. This review addresses the current state of understanding with respect to the ability of non‐renal stem cell sources to influence renal repair, the existence of endogenous renal stem cells and the biology of normal renal repair in response to damage. It also examines the remaining challenges and asks the question of whether there is one solution for all forms of renal disease. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Treatment results in patients with retinoblastoma and invasion to the cut end of the optic nerve
Authors: Chantada Guillermo L. , Guitter Myriam R. , Fandiño Adriana C. , Raslawski Elsa C. , de Davila Maria T.G. , Vaiani Elisa , Scopinaro Marcelo J.
Published: October 2008

Background

There is little information on the outcome of patients with retinoblastoma and tumor at the resection margin of the optic nerve.

Procedure

Retrospective evaluation of three successive prospective protocols. Twenty‐six consecutive patients were analyzed (International Staging System—IRSS‐stage 2 = 21, stage 3 = 5) from three successive prospective protocols (1988–2006). Patients with stage 2 were enucleated upfront and those with stage 3 had neoadjuvant chemotherapy followed by enucleation and adjuvant therapy. Both groups received adjuvant chemotherapy and orbital radiotherapy after enucleation. Patients in protocol 1 received 1 year of the lower‐dose chemotherapy regimen including cyclophosphamide, vincristine and doxorubicin along with intrathecal chemotherapy. Patients of protocols 2 and 3 received a more intense and shorter intravenous regimen including carboplatin and etoposide alternating with cyclophosphamide, idarubicin and vincristine with no intrathecal treatment. The components of protocol 2 and 3 were similar except for the dose of carboplatin which was 10% lower in protocol 3.

Results

Thirteen were treated in protocol 1 and 13 in protocols 2 and 3. The probability of event‐free survival was 0.70 at 5 years. Events included: CNS relapse = 3, second malignancies = 3, death in complete remission = 2. There were no significant differences in outcome between protocols or stages. Endocrinological disturbances related to the hypothalamus–hypophysis axis were evident in 6/8 patients evaluated. Severe orbital sequelae occurred in 12 cases.

Conclusions

A substantial number of patients with tumor at the resection margin of the optic nerve can be cured with current therapy; however, therapy related sequelae are frequent. Pediatr Blood Cancer 2009;52:218–222. © 2008 Wiley‐Liss, Inc.
Germ cell tumors of the head and neck: Report from the MAKEI Study Group
Authors: Bernbeck Beate , Schneider Dominik T. , Bernbeck Benedikt , Koch Susanne , Teske Carmen , Lentrodt Jürgen , Harms Dieter , Göbel Ulrich , Calaminus Gabriele ,   on Behalf of the MAKEI‐Study Group
Published: October 2008

Background

Germ cell tumors (GCTs) of the head and neck region are rare but may pose significant problems for perinatal management as well as surgical and adjuvant therapy.

Procedure

Thirty‐two prospectively reported patients from the German MAKEI studies (Maligne Keimzelltumoren) were analyzed with regard to perinatal management and long‐term survival.

Results

Twenty‐three tumors were diagnosed around birth and four during the first 3 months of life. All were primarily diagnosed as teratomas, but in two tumors, yolk sac tumor (YST) foci were identified. Another pure teratoma was diagnosed at 12 months. Four tumors were diagnosed after the first year of life and showed YST as leading histology. Most neonates presented with huge tumors causing external airway obstruction. All tumors were resected (complete resection, 16/26 patients with complete surgical information; incomplete resection, 10/26 patients). Eight tumors including five of six YSTs were treated with chemotherapy. In total, six patients relapsed. Relapse rate was higher after incomplete (5/10 patients) than after complete resection (1/16 patients). Accordingly, more relapses were observed in pharyngeal than in neck tumors due to incomplete resection. Nevertheless, half of the patients with incomplete resection remained in remission. One patient with YST died after multiple relapses.

Conclusions

GCTs of the head and neck region require a multidisciplinary approach in specialized centers. Most patients with antenatal tumor growth are identified by ultrasound and delivered preterm by cesarian section. After delivery, immediate intubation and ventilation aim for respiratory stabilization, followed by elective resection. With this approach, outcome was favorable. Pediatr Blood Cancer 2009;52:223–226. © 2008 Wiley‐Liss, Inc.
One year follow‐up of children and adolescents with chronic immune thrombocytopenic purpura (ITP) treated with rituximab
Authors: Mueller Brigitta U. , Bennett Carolyn M. , Feldman Henry A. , Bussel James B. , Abshire Thomas C. , Moore Theodore B. , Sawaf Hadi , Loh Mignon L. , Rogers Zora R. , Glader Bertil E. , McCarthy Maggie C. , Mahoney Donald H. , Olson Thomas A. , Feig Stephen A. , Lorenzana Adonis N. , Mentzer William C. , Buchanan George R. , Neufeld Ellis J. ,   for the Pediatric Rituximab/ITP Study Group, the Glaser Pediatric Research Network.
Published: October 2008

Background

We previously showed in a prospective study that rituximab appears to be effective in some children and adolescents with severe chronic immune thrombocytopenia. Eleven of 36 patients achieved and maintained platelet counts over 50,000/mm3 within the first 12 weeks. These patients were followed for the next year.

Methods

Platelet counts were monitored monthly and all subsequent bleeding manifestations and need for further treatment was noted.

Results

Eight of the 11 initial responders maintained a platelet count over 150,000/mm3 without further treatment intervention. Three patients had a late relapse. One initial non‐responder achieved a remission after 16 weeks, and two additional patients maintained platelet counts around 50,000/mm3 without the need for further intervention.

Conclusions

Rituximab resulted in sustained efficacy with platelet counts of 50,000/mm3 or higher in 11 of 36 patients (31%). Pediatr Blood Cancer 2009;52:259–262. © 2008 Wiley‐Liss, Inc.
Renal cell carcinoma in the pediatric population: Results from the California Cancer Registry
Authors: Silberstein Jonathan , Grabowski Julia , Saltzstein Sidney L. , Kane Christopher J.
Published: October 2008

Background

Renal cell carcinoma (RCC) is a rare disease in children and adolescents. This study aimed to review epidemiologic characteristics and survival for pediatric RCC patients using a large, population‐based database.

Procedure

The California Cancer Registry (CCR) was reviewed from 1988 to 2004. All cases of RCC in patients younger than 21 years were identified and annual age‐adjusted incidence rates were determined for the overall population and subdivided by ethnicity. Tumors were classified by stage and grade, and actuarial mortality rates were calculated.

Results

From 1988 to 2004, 43 cases of RCC were identified in patients younger than 21 years, accounting for 4.3% of all renal tumors in this age group. The overall annual age‐adjusted incidence was 0.01/100,000 with the tumor more common in non‐Hispanic blacks (0.03/100,000) compared to non‐Hispanic whites (0.01/100,000), Hispanics (<0.01/100,000), and non‐Hispanic Asians/Pacific Islanders (<0.01/100,000). The mean age at presentation was 15.4 years (SD 4.03, SE 0.615). RCC was identified more frequently in females (58.14%). At the time of presentation, 53.49% of tumors were localized, 20.93% were regionally advanced, and 25.58% were metastatic. The observed actuarial survival at 5 and 10 years was 61% (±15.7%).

Conclusion

Pediatric RCC is an uncommon and aggressive tumor that occurs most frequently in children in the second decade of life, more often in females and blacks. The epidemiological characteristics of this tumor differ from adult RCC and Wilms tumor, suggesting its distinctive biology and potential need for alternative treatment strategies. Pediatr Blood Cancer 2009;52:237–241. © 2008 Wiley‐Liss, Inc.
Vascular abnormalities in pediatric craniopharyngioma patients treated with radiation therapy
Authors: Liu Arthur K. , Bagrosky Brian , Fenton Laura Z. , Gaspar Laurie E. , Handler Michael H. , McNatt Sean A. , Foreman Nicholas K.
Published: October 2008

Background

Craniopharyngioma is a benign brain tumor that can be treated with some combination of surgery, intracystic chemotherapy and radiation therapy. Treatment for craniopharyngioma, especially radiation therapy, is associated with a variety of long‐term toxicities including vascular abnormalities. We report on the incidence of vascular abnormalities seen in the children with craniopharyngioma who received radiation therapy at our institution.

Procedure

We reviewed our experience with craniopharyngioma patients who received radiation therapy from 1995 to 2008. We reviewed clinical data including surgery, chemotherapy, radiation therapy and imaging for vasculopathy.

Results

Twenty of the 22 children with craniopharyngioma who received radiation therapy had imaging available. Six of the 20 were found to have some type of vasculopathy. One had bilateral temporal cavernomas, one had moyamoya syndrome, one had an aneurysm of the internal carotid artery and three children had decreases in the caliber of the carotid or cerebral arteries, but were asymptomatic. Two of the six children with abnormalities also received intracystic bleomycin prior to radiation therapy.

Conclusions

We report a high incidence of vascular abnormalities in children with craniopharyngioma. The data suggest that intracystic bleomycin may contribute to radiation‐related vasculopathy. We now include magnetic resonance angiography as part of our routine follow up in these children. Pediatr Blood Cancer 2009;52:227–230. © 2008 Wiley‐Liss, Inc.
On the design of end tabs for quasi‐static and fatigue testing of fibre‐reinforced composites
Authors: De Baere I. , Van Paepegem W. , Degrieck J.
Published: October 2008

The use of end tabs is often necessary when performing quasi‐static uniaxial tests on fibre‐reinforced composites. However, finding a suitable combination of material and geometry for these end tabs to have acceptable and reproducible results may be a problem. In this article four different geometries and four different materials of the tabs are numerically examined for the tensile testing of a carbon fabric reinforced polyphenylene sulphide. First, it is assessed if a simplified finite element model of a tensile grip is acceptable. Then, this simplified model is used to examine the proposed set‐ups. It may be concluded that, for the given material, short straight end tabs with a [(0°,90°)]4s layup should be used and the specimen should be mounted in such a way that the end tabs are completely between the grips. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Development of a polyamide nanocomposite for food industry: Morphological structure, processing, and properties
Authors: Pereira David , Losada Perfecto Paseiro , Angulo Inmaculada , Greaves William , Cruz Jose M.
Published: October 2008

In the last few years, nanocomposites have been a focus of attention for researchers because they frequently exhibit unexpected hybrid properties derived from synergistic reactions between nanoparticles and the polymeric matrix. However, few studies about the dispersion of inorganic clay minerals in polyamide films have been carried out to explain the process of exfoliation. The exfoliation of nanoclays in the polyamide film provides a film with better barrier properties than the intercalation of nanoclays. The present study addresses the analysis of experimental variables (pressure, temperature, processing time, feed position, etc.) involved in the production of a polyamide film with nanoparticles, in order to obtain a film with good exfoliation, barrier and mechanical properties. SEM, TEM and XRD were also evaluated as tools to determine the degree of exfoliation of nanoparticles. The technique used in production of the film, the screw employed and the mixing time were found to be of great importance in obtaining an intercalated or exfoliated final product. The variables involved in obtaining an exfoliated Cloisite 30B/polyamide film by a double screw extruder were optimized, and a film with reduced permeability to oxygen (1,000 times lower than the control film) wasobtained. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Photopolymerization and characteristics of reactive organoclay–polyurethane nanocomposites
Authors: Tan Hailin , Ma Guiping , Xiao Ming , Nie Jun
Published: October 2008

Polymerizable ammonium surfactants with two methacrylate alkyl chains were successfully synthesized via Michael‐Addition and quaternization reaction. Organoclays containing reactive methacrylate groups were prepared by cationic exchange process. Intercalated nanocomposites have been produced by UV initiated polymerization with different organophilic clay loading. X‐ray diffraction (XRD) spectroscopy showed that the d spacing of organoclay increased with increment of methacrylate alkyl chains length. When organoclay were dispersed in urethane acrylate resin, and photopolymerized, the d spacing increased, but the increasing extent decreased with increment of the methacrylate alky chains length. Thermogravimetric analysis indicated that incorporation of reactive organoclay had better thermal stablity than cetyltrimethylammonium bromide (CTMA)‐modified organoclay and dynamic mechanical analysis (DMA) showed nanocomposites containing reactive organoclay had high glass transition temperature and storage modulus. Tensile analysis implied that incorporation of reactive organoclay could enhance mechanical and tensile properties dramatically. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Wollastonite‐reinforced polypropylene composites modified with novel metallocene EPR copolymers. II. Mechanical properties and adhesion
Authors: Švab Iztok , Musil Vojko , Pustak Anđela , Šmit Ivan
Published: October 2008

Mechanical properties and adhesion phenomena of isotactic polypropylene/wollastonite/metallocene propylene‐ethylene copolymers (iPP/W/EPR) composites were studied as a function of metallocene propylene‐based copolymers content from 0 to 20 vol%. The composites with different surface treated wollastonites and two types of EPR have shown similar behavior of most mechanical properties except elongation at break and impact strength respective of the difference in some characteristics of used EPR elastomers. The increase and the difference in elongation at break could be explained by renewed spherulitic morphology of the iPP matrix. Stronger interactions between EPR‐1 and two used types of wollastonites than between EPR‐2 and corresponding wollastonites concluded from the surface properties led to the difference in impact strength behavior. The determined mechanical properties confirm the assumption coming out of structural investigations that metallocene EPR elastomers are rather efficient impact modifiers than encapsulation compatibilizers for the iPP/wollastonite composites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Experimental study of sharp‐tipped projectile perforation of GFRP plates containing sand filler under high velocity impact and quasi‐static loadings
Authors: Sabet Ali Reza , Beheshty Mohammad Hosain , Rahimi Hamid
Published: October 2008

Penetration and perforation behavior of glass fiber reinforced plastic (GFRP) plates containing 20% sand filler have been investigated via high velocity impact tests using sharp tipped (30°) projectile and quasi‐static perforation tests. Two size sand filler (75 and 600 μm) were used in 4‐, 8‐, and 14‐layered laminated composite plates to study sensitivity of filler size toward loading system. Composite plates were examined for perforation load rate at 5 mm/min and high‐velocity impact loading up to 220 m/s. Results indicated higher energy absorption for GFRP plates containing sand filler for both high‐velocity impact and quasi‐static perforation tests. Higher ballistic limits were recorded for specimens containing sand filler. The study showed clear role played by coarse‐sized sand filler as a secondary reinforcement in terms of higher energy absorption as compared with nonfilled and specimens containing fine‐sized fillers. The investigation successfully characterized behavior of quasi‐static test during penetration and perforation of the sharp‐tipped indenter as an aid for impact application studies. Residual frictional load in the specimens containing sand filler constituted considerable portion of load bearing during perforation in quasi‐static tests. Delaminations followed by fiber and matrix fracture were major failure mode in high‐velocity tests and the main energy absorbing mechanism in thick‐walled plates, whereas in quasi‐static tests the failures were more of matrix fracture and fiber sliding. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Isothermal crystallization behavior of poly(L‐lactic acid)/organo‐montmorillonite nanocomposites
Authors: Li Xiaoxiu , Yin Jingbo , Yu Zhenyang , Yan Shifeng , Lu Xiaochun , Wang Yinjie , Cao Bin , Chen Xuesi
Published: October 2008

The isothermal crystallization behavior of poly(L‐lactic acid)/organo‐montmorillonite nanocomposites (PLLA/OMMT) with different content of OMMT, using a kind of twice‐functionalized organoclay (TFC), prepared by melt intercalation process has been investigated by optical depolarizer. In isothermal crystallization from melt, the induction periods (ti) and half times for overall PLLA crystallization (100°C ≤ Tc ≤ 120°C) were affected by the temperature and the content of TFC in nanocomposites. The kinetic of isothermal crystallization of PLLA/TFC nanocomposites was studied by Avrami theory. Also, polarized optical photomicrographs supplied a direct way to know the role of TFC in PLLA isothermal crystallization process. Wide angle X‐ray diffraction (WAXD) patterns showed the nanostructure of PLLA/TFC material, and the PLLA crystalline integrality was changed as the presence of TFC. Adding TFC led to the decrease of equilibrium melting point of nanocomposites, indicating that the layered structure of clay restricted the full formation of crystalline structure of polymer. The specific interaction between PLLA and TFC was characterized by the Flory‐Huggins interaction parameter (B), which was determined by the equilibrium melting point depression of nanocomposites. The final values of B showed that PLLA was more compatible with TFC than normal OMMT. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers