bluuebunny/crossref_metadata_2025 huggingface dataset:
Pentadecapeptide BPC 157 (PL 14736) improves ligament healing in the rat
Authors: Cerovecki Tomislav , Bojanic Ivan , Brcic Luka , Radic Bozo , Vukoja Ivan , Seiwerth Sven , Sikiric Predrag
Published: March 2010

We improved medial collateral ligament (MCL) healing throughout 90 days after surgical transection. We introduced intraperitoneal, per‐oral (in drinking water) and topical (thin cream layer) peptide therapy always given alone, without a carrier. Previously, as an effective peptide therapy, stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, an anti‐ulcer peptide effective in inflammatory bowel disease therapy (PL 14736)) particularly improved healing of transected tendon and muscle and wound healing effect including the expression of the early growth response 1 (egr‐1) gene. After MCL transection BPC 157 was effective in rats when given once daily intraperitoneally (10 µg or 10 ng/kg) or locally as a thin layer (1.0 µg dissolved in distilled water/g commercial neutral cream) at the site of injury, first application 30 min after surgery and the final application 24 h before sacrifice. Likewise, BPC 157 was effective given per‐orally (0.16 µg/ml in the drinking water (12 ml/day/rat)) until sacrifice. Commonly, BPC 157 µg‐ng‐rats exhibited consistent functional, biomechanical, macroscopic and histological healing improvements. Thus, we suggest BPC 157 improved healing of acute ligament injuries in further ligament therapy. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1155–1161, 2010
Age‐associated increases in the size of the infrapatellar fat pad in knee osteoarthritis as measured by 3T MRI
Authors: Chuckpaiwong Bavornrit , Charles Hal Cecil , Kraus Virginia B. , Guilak Farshid , Nunley James A.
Published: March 2010

Obesity, as a primary risk factor for osteoarthritis (OA), has been shown to alter joint loading, but may also result in metabolic changes characterized by chronic, low‐level inflammation due to increased circulating levels of adipose‐derived cytokines, or “adipokines.” The presence of the infrapatellar fat pad in the knee suggests that local changes in adipokine concentrations may influence knee OA. This study examined the hypotheses that the volume of the infrapatellar fat pad is correlated to the body mass index (BMI) of OA patients, and that fat pad volume is greater in subjects with OA. Fat pad volume was measured in sequential magnetic resonance (MR) images taken over one year in a cohort of 15 control and 15 knee OA subjects. No differences were observed in the fat pad volume between the two groups at baseline, 3, 6, or 12 months. In control subjects, no significant correlations were present between any parameters (age, BMI, weight, volume of fat pad at any time point). However, in the osteoarthritic group, fat pad volume was correlated with age at every time point. One possible explanation is that local factors related to knee OA may also induce enlargement of the fat pad with age. Alternatively, subjects who are prone to growth or enlargement of the fat pad may also be more prone to symptomatic OA. These findings provide intriguing preliminary data on the potential role of the infrapatellar fat pad in OA, although additional study is required to better understand the mechanisms of this relationship. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1149–1154, 2010
Musculoskeletal deformities secondary to neurotomy of the superior trunk of the brachial plexus in neonatal mice
Authors: Kim H. Mike , Galatz Leesa M. , Das Rosalina , Patel Nikunj , Thomopoulos Stavros
Published: March 2010

The developmental course of musculoskeletal deformities in neonatal brachial plexus palsy (NBPP) has not been studied extensively. The goals of this study were to: (1) evaluate a new animal model of NBPP, (2) characterize the development of musculoskeletal abnormalities in paralyzed shoulders, and (3) investigate the expression of myogenic and adipogenic genes in paralyzed rotator cuff muscles. Neonatal mice were divided into neurotomy and sham groups. The neurotomy group underwent surgical transection of the superior trunk of the brachial plexus within 24 h of birth. The sham group underwent the same surgical exposure, but the brachial plexus was left intact. Musculoskeletal deformities were evaluated with radiological and histological assays at 2, 4, 8, 12, and 30 weeks after birth. The supraspinatus muscles of a separate group of mice were used to examine expression of myogenic and adipogenic genes at 8 weeks. The neurotomized forelimbs developed deformities similar to those seen in human NBPP. The deformities progressed with age. The denervated supraspinatus muscles showed intramuscular fat accumulation and upregulation of both myogenic and adipogenic genes compared to the normal. The current study presents a useful animal model for future research examining musculoskeletal changes secondary to neonatal nerve injury. Published by Wiley Periodicals, Inc. J Orthop Res 28:1391–1398, 2010
Changes in chondrogenic phenotype and gene expression profiles associated with the in vitro expansion of human synovium‐derived cells
Authors: Han Hyuk‐Soo , Lee Sahnghoon , Kim Ji Hyun , Seong Sang Cheol , Lee Myung Chul
Published: March 2010

We undertook this study to characterize changes in the proliferative capacities, chondrogenic phenotypes, and gene expression profiles of human synovium‐derived progenitor cells from osteoarthritic patients during in vitro expansion. Cells isolated from osteoarthritic synovia were cultured, and growth rates during serial passages were evaluated. Surface molecule expressions were determined by flow cytometry and cytogenetic analyses were performed. After chondrogenic differentiation in cell pellets, we evaluated type II collagen and glycosaminoglycan (GAG) synthesis. To assess whether the in vitro expansion of synovium‐derived cells affects gene expression, we performed microarray analyses on cells at passage 0, 1, 2, 4, 6, and 8. Synovium‐derived cells were rapidly expanded in vitro through passage 8 (about 130 days), and after passage 6, the proliferation rates decreased slightly with a wide range of individual variations. The expressions of CD166, CD49a, and CD106 decreased, whereas those of CD10, CD29, CD44, CD73, CD90, and CD105 showed no significant change. Karyotype analysis revealed no evidence of chromosome abnormalities. The staining of type II collagen and GAG in differentiated cell pellets showed rapid weakening. Genome‐wide microarray analysis showed that synovium‐derived cells from late passages over‐expressed genes associated with cell cycle prolongation and cell aging, and less‐expressed genes associated with cell growth stimulation. The in vitro expansion of synovium‐derived cells was accompanied with decreased proliferative capacity and the chondrogenic phenotype, which might be modulated by change in gene expression patterns. Published by Wiley Periodicals, Inc. J Orthop Res 28:1283–1291, 2010
Correlations between effective permeability and marrow contact channels surface of vertebral endplates
Authors: Laffosse Jean‐Michel , Accadbled Franck , Molinier François , Bonnevialle Nicolas , de Gauzy Jérôme Sales , Swider Pascal
Published: March 2010

Homeostasis of the intervertebral disc relies on nutrient supply and waste clearance through the dense capillary network that is in contact with the cartilage endplate (CEP). We developed a micro‐computerized tomography (micro‐CT) method to quantify the marrow contact channel surface (MCCS) with the CEP and to validate the hypothesis according to which MCCS was correlated to the effective permeability of the vertebral endplate (VEP) and influenced by the mechanical stimuli. The influence of compression loading on local vascularization was investigated. Six 4‐week‐old skeletally immature pigs were instrumented with left pedicle screws and rod at both T5–T6 and L1–L2 levels to create asymmetrical spine tethers. After 3 months of growth, three cylindrical specimens of the VEP (one central and two lateral right and left) were obtained from both the instrumented and the control levels. We used a previously validated method for measuring permeability. Micro‐CT analysis (resolution 12 µm) yielded a gray‐scale 2D‐image of the discal end of each specimen converted into a binary 2D‐image to derive the MCCS. Correlations between MCCS and effective permeability were assessed. Effective permeability and MCCS were significantly decreased compared to the control group especially on the tethered side (−41.5%, p = 0.004 and −52.5%, p = 0.0009, respectively). Correlations were significant and showed maximal value (r2 = 0.430, p < 0.0001) on the tethered side involving maximal compressive loadings. Mechanical stimuli, due to unbalanced growth, altered the vascularization and the convective properties of the CEP. The cascade of mechanobiological events should offer perspectives for research on disc degeneration and attempted treatment. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1229–1234, 2010
Raman spectroscopy for the analysis of coal: a review
Authors: Potgieter‐Vermaak S. , Maledi N. , Wagner N. , Van Heerden J. H. P. , Van Grieken R. , Potgieter J. H.
Published: March 2010

The advances in the characterization of amorphous carbons by Raman spectroscopy over the last four decades are of interest to many industries, especially those involving the combustion, gasification and pyrolysis of coal. Many researchers report on the Raman character of the natural organic matter in carbon‐containing compounds, such as coal, and relate the Raman bands to the structural order of the amorphous carbons. The basis of most of these studies evolved around the assignment of the G (graphitic, ∼1580 cm−1) band to crystalline graphite and any other bands, called D bands, (disorder, various from 1100 to 1500 cm−1) to any type of structural disorder in the graphitic structure. Concerning coal analysis, the information gained by Raman investigations has been used to describe char evolution as a function of temperature, the presence of catalysts and different gasification conditions. In addition, researchers looked at maturation, grade, doppleritization and many more aspects of interest. One aspect that has, however, not been addressed by most of the researchers is the natural inorganic matter (NIM) in the carbon‐containing compounds. Micro‐Raman spectroscopy (MRS) has many advantages over other characterization tools, i.e. in situ analysis, nondestructive, no sample preparation, low detection limit, micrometer‐scale characterization, versatility and sensitivity to many amorphous compounds. With the distinct advantages it has over that of other molecular characterization tools, such as powder X‐ray diffraction (PXRD), Fourier‐transform infrared spectrometry (FT‐IR) and scanning electron microscopy with X‐ray detection (SEM/EDS), it is surprising that it has not yet been fully exploited up to this point for the characterization of the NIM in coal and other amorphous carbons. This paper reviews the work published on the Raman characterization of the natural organic matter (NOM) of coals and reports on preliminary results of the NIM character of various South African coals, whereby various inorganic compounds and minerals in the coal have been characterized. Copyright © 2010 John Wiley & Sons, Ltd.
The impact of criminal justice involvement on victims' mental health
Authors: Parsons Jim , Bergin Tiffany
Published: March 2010

The aftermath of violent crime can leave victims with persistent emotional and mental health problems. Although research has shown the potential benefits of prosecuting cases through the courts, there is also a substantial literature that suggests that common features of the criminal justice system can exacerbate the impact of the initial crime, leading to a secondary victimization. The authors present a review of the research on the positive and negative impact of criminal justice involvement, and common points of failure in the efforts of justice institutions to meet the needs of victims. They conclude with recommendations for future work, including the need for research on restorative justice, victim impact statements, court notification systems, victim services, and victim advocates.
Influence of colloid suspensions of humic acids on the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide
Authors: Astray G. , García‐Río L. , Lodeiro C. , Mejuto J. C. , Moldes O. , Morales J. , Moyano F.
Published: March 2010

The influence of humic substances (HSs) upon the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide has been studied. Important inhibition of hydrolysis reaction has been reported. This inhibition has been explained in terms of association of reactants to the humic substances. Kinetic results have been modeled using the micellar pseudophase model. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 316–322, 2010
Kinetic isotope effects for the H2 + C2H ↔ C2H2 + H reaction based on the ab initio calculations and a global potential energy surface
Authors: Ju Liping , Wang Dongsheng
Published: March 2010

In the present paper, kinetic isotope effects of the title reaction are studied with canonical variational transition state theory on the modified Wang Bowman (MWB) potential energy surface (PES) (Chem Phys Lett 2005, 409, 249) and the ab initio calculations at the quadratic configuration interaction (QCISD (T, full))/aug‐cc‐pVTZ//QCISD (full)/cc‐pVTZ level. The calculated rate constants for the isotopic variants of this title reaction on the MWB PES have good agreement with those of the present ab initio calculations over the temperature range of 20–5000 K for the forward reactions and 800–5000 K for the reverse reactions, respectively. In particular, the forward rate constants for the title reaction and its isotopically substituted reactions have negative temperature dependences at about 40 K. Rate expressions are presented for all the studied reactions. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 289–298, 2010
Modeling and experimental studies on combustion characteristics of porous coal char: Volume reaction model
Authors: Sadhukhan Anup Kumar , Gupta Parthapratim , Kumar Saha Ranajit
Published: March 2010

A generalized single‐particle model for the prediction of combustion dynamics of a porous coal char in a fluidized bed is analyzed in the present work using a volume reaction model (VRM). A fully transient nonisothermal model involving both heterogeneous and homogeneous chemical reactions, multicomponent mass transfer, heat transfer with intraparticle resistances, as well as char structure evolution is developed. The model takes into account convection and diffusion inside the particle pores, as well as in the boundary layer. By addressing the Stefan flow originated due to nonequimolar mass transfer and chemical reactions, this work enables a more realistic analysis of the combustion process. The model, characterized by a set of partial differential equations coupled with nonlinear boundary conditions, is solved numerically using the implicit finite volume method (FVM) with a FORTRAN code developed in‐house. The use of a FVM for solving such an elaborate char combustion model, based on the VRM, was not reported earlier. Experiments consisting of fluidized‐bed combustion of a single char particle were carried out to determine the internal surface area of a partially burned char particle and to enable model validation. Predicted results are found to compare well with the reported experimental results for porous coal char combustion. The effects of various parameters (i.e., bulk temperature and initial particle radius) are examined on the dynamics of combustion of coal char. The phenomena of ignition and extinction are also investigated. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 299–315, 2010
Stathmin1 overexpression associated with polyploidy, tumor‐cell invasion, early recurrence, and poor prognosis in human hepatoma
Authors: Hsieh Sen‐Yung , Huang Shiu‐Feng , Yu Ming‐Chin , Yeh Ta‐Sen , Chen Tse‐Chin , Lin Yu‐Jr , Chang Chee‐Jen , Sung Chang‐Mung , Lee Yun‐Lin , Hsu Chih‐Yun
Published: March 2010

Frequent intrahepatic metastasis causes early tumor recurrence and dismaying prognosis of human hepatocellular carcinoma (HCC). We recently identified overexpression of stathmin1 (STMN1) in human HCC. This study was designed to elucidate the clinical and biological significance of overexpression of STMN1 in HCC. Expression of STMN1 was conducted by quantitative reverse transcription‐polymerase chain reaction and immunoblotting assays on 58 pairs of HCC and para‐tumor liver tissues from patients with HCC along with normal liver tissues as the controls. Association of STMN1 overexpression with tumor recurrence and prognosis was investigated by Kaplan–Meier cumulative survival and Cox Regression analyses. Roles of STMN1 in cell cycle, cell motility, and invasion were determined by in vitro assays. STMN1 overexpression in hepatoma was strongly associated with local invasion (P = 0.031), early recurrence (P = 0.002), and poor prognosis (P = 0.005), and was an independent indicator for tumor recurrence (P = 0.0045). STMN1 overexpression further identified subgroups of HCC patients with higher tumor recurrence and worse prognosis among HCC patients with early tumor stage (T1) or intermediate histological grades (G2 and G3), both of whom represent the majority of HCC patients receiving primary curative hepatectomy. Silencing STMN1 expression via RNA interference suppressed invasion activity, while ectopic expression of STMN1 enhanced cell invasion and caused polyploidy of cells. In conclusion, STMN1 overexpression could predict early tumor recurrence and poor prognosis, particularly at early stage of hepatoma. Overexpression of STMN1 promoted polyploidy formation, tumor‐cell invasion, and intrahepatic metastasis, suggesting that STMN1 can be a target for anti‐cancer therapy of human hepatoma. © 2010 Wiley‐Liss, Inc.
Estimated drug use based on direct questioning and open‐ended questions: responses in the 2006 National Survey on Drug Use and Health
Authors: Kroutil Larry A. , Vorburger Michael , Aldworth Jeremy , Colliver James D.
Published: March 2010

Substance use surveys may use open‐ended items to supplement questions about specific drugs and obtain more exhaustive information on illicit drug use. However these questions are likely to underestimate the prevalence of use of specific drugs. Little is known about the extent of such underestimation or the groups most prone to under‐reporting. Using data from the 2006 National Survey on Drug Use and Health (NSDUH), a civilian, non‐institutionalized population survey of persons aged 12 or older in the United States, we compared drug use estimates based on open‐ended questions with estimates from a new set of direct questions that occurred later in the interview. For these drugs, estimates of lifetime drug use based on open‐ended questions often were at least seven times lower than those based on direct questions. Among adults identified in direct questions as substance users, lower educational levels were consistently associated with non‐reporting of use in the open‐ended questions. Given NSDUH's large annual sample size (∼67  000 interviews), combining data across future survey years could increase our understanding of characteristics associated with non‐reporting of use in open‐ended questions and allow drug use trends to be extrapolated to survey years in which only open‐ended question data are available. Copyright © 2010 John Wiley & Sons, Ltd.
Cucurbitane‐type triterpene glycosides from the fruits of Momordica charantia
Authors: Nhiem Nguyen Xuan , Kiem Phan Van , Minh Chau Van , Ban Ninh Khac , Cuong Nguyen Xuan , Ha Le Minh , Tai Bui Huu , Quang Tran Hong , Tung Nguyen Huu , Kim Young Ho
Published: March 2010

The chemical study of Momordica charantia fruits led to the isolation of three new cucurbitane triterpene glycosides, momordicosides U, V, and W (1–3). The structures of these compounds were determined to be (19R, 23R)‐5β, 19‐epoxy‐19‐methoxycucurbita‐6,24‐diene‐3β, 23‐diol 3‐O‐β‐D‐allopyranoside (1), (23R)‐5β, 19‐epoxycucurbita‐6,24‐diene‐3β, 23‐diol 3‐O‐β‐D‐allopyranoside (2), and (19R)‐5β, 19‐epoxy‐19,25‐dihydroxycucurbita‐6,23(E)‐diene‐3β‐ol 3‐O‐β‐D‐glucopyranoside (3), by chemical and spectroscopic methods. Copyright © 2010 John Wiley & Sons, Ltd.
Probabilistic yielding and cyclic behavior of geomaterials
Authors: Sett Kallol , Jeremić Boris
Published: March 2010

In this paper, the novel concept of probabilistic yielding is used for 1‐D cyclic simulation of the constitutive behavior of geomaterials. Fokker–Planck–Kolmogorov equation‐based probabilistic elastic–plastic constitutive framework is applied for obtaining the complete probabilistic (probability density function) material response. Both perfectly plastic and hardening‐type material models are considered. It is shown that when uncertainties in material parameters are taken into consideration, even the simple, elastic‐perfectly plastic model captures some of the important features of geomaterial behavior, for example, modulus reduction with cyclic strain, which, deterministically, is only possible with more advanced constitutive models. Furthermore, it is also shown that the use of isotropic and kinematic hardening rules does not significantly improve the probabilistic material response. Copyright © 2010 John Wiley & Sons, Ltd.
Estimation of potential failure risks in a mine slope using indicator kriging
Authors: Lana M. S. , Cabral I. E. , Gripp A. H. , Gripp M. F. A.
Published: March 2010

Indicator kriging has been applied to the study of failure mechanisms in a mine slope in Minas Gerais, Brazil, to estimate potential failure risks in limited areas along this slope. Timbopeba Mine, Vale Company, is an open pit iron mine situated in the Quadrilátero Ferrífero, a very important mining district in Minas Gerais. A slope excavated in quartzite with a maximum height of 200 m at the time of this study, has presented many failure problems involving the sliding of blocks formed by discontinuities. These blocks are of limited size in comparison to the dimensions of the overall slope. They appear along the entire slope, wherever discontinuity orientations have led to the kinematic feasibility of these blocks. Geostatistics permits the estimation of local failure probability distributions associated to these local failures, which would not be possible with traditional statistical models. The geostatistical method employed in this study, indicator kriging, is quite suitable because it is unnecessary to assume a particular global distribution of the phenomena being modeled. The model was used for locating areas with a great tendency for sliding failure, as it considers the local spatial variability of discontinuity orientations. Copyright © 2010 John Wiley & Sons, Ltd.
Modeling the interaction between fluid flow and particle movement with discontinuous deformation analysis (DDA) method
Authors: Koyama Tomofumi , Nishiyama Satoshi , Yang Meng , Ohnishi Yuzo
Published: March 2010

Coupled hydro‐mechanical processes in granular media represent the interaction between solid particles movement and fluid flow during external and/or internal loading. The processes attract attention in geotechnical engineering since they cause many disasters such as landslide, slope collapse, boiling/quicksand and soil liquefaction, etc. This study presents a numerical method combining discontinuous deformation analysis (DDA) for mechanical calculation and finite element method for fluid flow simulation to model the interaction between solid particles' movement and fluid flow from microscopic point of view. The term of hydraulic pressure was newly formulated and introduced to the original DDA. The simplified examples are given to verify the new method, and the computational results correlate well with the theoretical calculations, further development is also considered. Copyright © 2010 John Wiley & Sons, Ltd.
Compressibility and permeability of sand–kaolin mixtures. Experiments versus non‐linear homogenization schemes
Authors: Boutin Claude , Kacprzak Grzegorz , Thiep Doanh
Published: March 2010

This study deals with the behaviour of mixtures of sand and saturated kaolin paste considered as composite materials made of permeable and deformable (with non‐linear behaviour) matrix (the kaolin paste) with rigid and impervious inclusions (the sand grains). Oedometric and permeability tests highlight the key role of the state of the clay paste, and show the existence of a threshold of sand grain concentration above which a structuring effect influences both compressibility and permeability. At the light of these experiments two homogenization schemes (with simplifying assumptions to make the problem manageable) are considered to model these two parameters. Qualitative and quantitative comparisons with experimental data point out their respective domain of interest and limitations: a tangent homogenization scheme is shown to be sufficient to describe the macroscopic properties for dilute sand concentration; above the concentration threshold, the structuring effect is captured by the new homogenization scheme developed in this paper. Copyright © 2010 John Wiley & Sons, Ltd.
Application of the exact constitutive relationship of modified Cam clay to the undrained expansion of a spherical cavity
Authors: Silvestri Vincenzo , Abou‐Samra Ghassan
Published: March 2010

The modified Cam clay (MCC) model is used to study the response of virgin‐compressed clay subjected to undrained triaxial compression. The MCC constitutive relationship is obtained in a closed form. Both elastic and plastic deviatoric strains are considered in the analysis. The solution allows to obtain total and effective stress paths followed by the clay in undrained spherical expansion. Pore water pressures are determined from the difference between total and effective mean stresses. For illustration purposes, the analysis is also applied to the well‐known reconstituted normally consolidated London clay and the results are compared with the recently published data obtained by a numerical approach. In addition, the Almansi large strains are used in the analysis, as these allow to obtain limit expansion and pore pressures, whereas both small‐strain and logarithmic‐strain approaches do not permit to determine them. Copyright © 2010 John Wiley & Sons, Ltd.
Study on interaction between dissimilar piles in layered soils
Authors: Zhang Qianqing , Zhang Zhongmiao
Published: March 2010

This paper, under the assumption that the pile–pile interaction showed elasticity, analyzed the pile–pile interaction between two dissimilar piles in layered soils using the shear displacement method and taking the sheltering effect into account to modify the conventional interaction factor between two dissimilar piles. The linear stiffness of single pile was adopted herein to analyze the influence of the pile stiffness factor, the pile length factor, and the diameter of shorter pile on the pile–pile interaction factor between two dissimilar piles. The interaction factor between two dissimilar piles drew from the present method was generally in good agreement with the interaction factor computed by Wong and Poulos. However, this paper intends to provide a different but more convenient means of estimating the interaction factor between piles that have dissimilar diameters, lengths and pile tip conditions, and the settlement of dissimilar piles in pile groups. Copyright © 2010 John Wiley & Sons, Ltd.
Dilatancy of granular materials in a strain space multiple mechanism model
Authors: Iai Susumu , Tobita Tetsuo , Ozutsumi Osamu , Ueda Kyohei
Published: March 2010

A granular material consists of an assemblage of particles with contacts newly formed or disappeared, changing the micromechanical structures during macroscopic deformation. These structures are idealized through a strain space multiple mechanism model as a twofold structure consisting of a multitude of virtual two‐dimensional mechanisms, each of which consists of a multitude of virtual simple shear mechanisms of one‐dimensional nature. In particular, a second‐order fabric tensor describes direct macroscopic stress–strain relationship, and a fourth‐order fabric tensor describes incremental relationship. In this framework of modeling, the mechanism of interlocking defined as the energy less component of macroscopic strain provides an appropriate bridge between micromechanical and macroscopic dilative component of dilatancy. Another bridge for contractive component of dilatancy is provided through an obvious hypothesis on micromechanical counterparts being associated with virtual simple shear strain. It is also postulated that the dilatancy along the stress path beyond a line slightly above the phase transformation line is only due to the mechanism of interlocking and increment in dilatancy due to this interlocking eventually vanishing for a large shear strain. These classic postulates form the basis for formulating the dilatancy in the strain space multiple mechanism model. The performance of the proposed model is demonstrated through simulation of undrained behavior of sand under monotonic and cyclic loading. Copyright © 2010 John Wiley & Sons, Ltd.
Bearing capacity factors of circular foundations for a general c–ϕ soil using lower bound finite elements limit analysis
Authors: Kumar Jyant , Khatri Vishwas N.
Published: March 2010

By using the lower bound limit analysis in conjunction with finite elements and linear programming, the bearing capacity factors due to cohesion, surcharge and unit weight, respectively, have been computed for a circular footing with different values of ϕ. The recent axisymmetric formulation proposed by the authors under ϕ=0 condition, which is based on the concept that the magnitude of the hoop stress (σθ) remains closer to the least compressive normal stress (σ3), is extended for a general c–ϕ soil. The computational results are found to compare quite well with the available numerical results from literature. It is expected that the study will be useful for solving various axisymmetric geotechnical stability problems. Copyright © 2010 John Wiley & Sons, Ltd.
Phenylbutyrate induces apoptosis and lipid accumulations via a peroxisome proliferator‐activated receptor gamma‐dependent pathway
Authors: Milkevitch Matthew , Beardsley Nancy J. , Delikatny E. James
Published: March 2010

The effects of the selective peroxisome proliferator activated receptor‐gamma (PPAR‐γ) inhibitor GW9662 on phenylbutyrate (PB)‐induced NMR‐detectable lipid metabolites was investigated on DU145 prostate cancer cells. DU145 cells were perfused with 10 mM PB in the presence or absence of 1 µM of GW9662 and the results monitored by 31P and diffusion‐weighted 1H NMR spectroscopy. GW9662 completely reversed PB‐induced NMR‐visible lipid and total choline accumulation in 1H spectra and glycerophosphocholine and β‐NTP in 31P spectra. In addition, pre‐incubation with GW9662 significantly reduced PB‐induced caspase‐3 activation, reversed the G1 block as measured by flow cytometry, and otherwise had little effect on cell survival as measured by MTT assay. These results suggest that the NMR visible lipid accumulation and apoptosis induced by PB treatment occurs through a mechanism that is mediated by PPAR‐γ. Copyright © 2010 John Wiley & Sons, Ltd.
Parallel geometric multigrid for global weather prediction
Authors: Buckeridge Sean , Scheichl Robert
Published: March 2010

The subject of this work is an optimal and scalable parallel geometric multigrid solver for elliptic problems on the sphere, crucial to the forecasting and the data assimilation tools used at the U.K. Met office. The optimality of multilevel techniques for elliptic problems makes them a suitable choice for these applications. The Met office uses spherical polar grids which, although structured, have the drawback of creating strong anisotropies near the poles. Moreover, a higher resolution in the radial direction introduces further anisotropies, and so modifications to the standard multigrid relaxation and the coarsening procedures are necessary to retain optimal efficiency. As the strength of anisotropy varies, we propose a non‐uniform strategy, coarsening the grid only in regions that are sufficiently isotropic. This is combined with line relaxation in the radial direction. The success of non‐uniform coarsening strategies has been demonstrated with algebraic multigrid (AMG) methods. Without the large setup costs required by AMG, however, we aim to surpass them with the geometric approach. We demonstrate the advantages of the method with experiments on model problems, both sequentially and in parallel, and show robustness and optimal efficiency of the method with constant convergence factors of less than 0.1. It substantially outperforms Krylov subspace methods with one‐level preconditioners and the BoomerAMG implementation of AMG on typical grid resolutions. The parallel implementation scales almost optimally on up to 256 processors, so that a global solve of the quasi‐geostrophic omega‐equation with a maximum horizontal resolution of about 10 km and 3 × 109 unknowns takes about 60 s. Copyright © 2010 John Wiley & Sons, Ltd.
High resolution DNA melting analysis: an application for prenatal control of α‐thalassemia
Authors: Sirichotiyakul Supatra , Wanapirak Chanane , Saetung Rattika , Sanguansermsri Torpong
Published: March 2010

Objective

To report the use of real‐time gap‐PCR using SYTO9 with high‐resolution melting analysis (HRMA) in prenatal diagnosis of α‐thalassemia 1.

Materials and methods

Real‐time gap‐PCR using SYTO9 with HRMA was performed in 33 DNA samples from chorionic villi sampling (8 normal, 16 heterozygous, and 9 homozygous) to determine the α‐thalassemia 1 gene [normal and Southeast Asia (−SEA) allele].

Result

The dissociation curve analysis in normal and − SEA allele gave a peak of Tm at 91.80 ± 0.14 °C and 88.67 ± 0.08 °C, respectively. Normal genotype and homozygous α‐thalassemia 1 showed a single peak of Tm that corresponded to their alleles. The heterozygotes gave both peaks with higher normal peak and smaller − SEA peak. Thirty one samples showed consistent results with the conventional gap‐PCR. Two samples with ambiguous results were confirmed to be maternal DNA contamination on real‐time quantitative PCR and microsatellite assay. HRMA from both samples showed similar pattern to that of heterozygotes. However, they showed much smaller normal peak compared with the − SEA peak, which is in contrast to those of heterozygotes and can readily be distinguished.

Conclusion

HRMA with SYTO9 is feasible for prenatal diagnosis of α‐thalassemia. It had potential advantage of prompt detection maternal DNA contamination. Copyright © 2010 John Wiley & Sons, Ltd.
RIE‐induced carrier lifetime degradation
Authors: Zin Ngwe Soe , Blakers Andrew , Weber Klaus
Published: March 2010

Reactive Ion Etching (RIE) is used in the fabrication of some types of solar cells to achieve a highly directional etch. However, cells fabricated using RIE have lower than expected efficiency, possibly caused by increased carrier recombination. Characterisation of the carrier lifetime in solar cells was conducted using the quasi steady state photoconductance (QSSPC) measurement technique. Substantial effective lifetime degradation was observed for silicon samples processed by RIE. Lifetime degradation for samples where RIE etches into silicon is found to be permanent, while for samples where RIE etches only on dielectric layers of SiO2 grown on the wafer, the lifetime degradation is found to be reversible. The reversible degradation in RIE‐processed samples is associated with radiation damage. By reducing the proportion of a wafer exposed to RIE, the degradation of the effective lifetime of RIE‐etched silicon samples can be minimised, and the performance of silicon solar cells can be improved significantly. Copyright © 2010 John Wiley & Sons, Ltd.
Comparison of emitter saturation current densities determined by injection‐dependent lifetime spectroscopy in high and low injection regimes
Authors: Reichel C. , Granek F. , Benick J. , Schultz‐Wittmann O. , Glunz S. W.
Published: March 2010

The determination of the emitter saturation current densityJ0eof symmetrical test structures, analyzed by injection‐dependent lifetime spectroscopy (IDLS), in high as well as in low injection regimes is compared. A detailed investigation of the influence of different models for the Auger recombination on the evaluation of the measured minority carrier lifetime is performed. It can be concluded that a good agreement for the extraction ofJ0eunder high and low injection conditions for lightly and highly doped emitters on textured and untextured surfaces was obtained if the Auger parameterization of Kerret al.is applied. For deep‐diffused emitter profiles on textured surfaces a significant increase ofJ0ewell above the geometrical surface area ratio of untextured and textured surfaces of 1.7 was observed. A verification of the experimentally determined values forJ0eis performed by numerical device simulations. The simulated surface recombination velocity for the investigated emitter doping profiles is in good agreement to analytical calculations. Copyright © 2010 John Wiley & Sons, Ltd.
Durability of Pb‐free solder between copper interconnect and silicon in photovoltaic cells
Authors: Cuddalorepatta Gayatri , Dasgupta Abhijit , Sealing Scott , Moyer Jerome , Tolliver Todd , Loman James
Published: March 2010

The thermal cycling durability of large‐area Pb‐free (Sn3.5Ag) solder between silicon semiconductor and copper interconnects in photovoltaic (PV) cells is assessed and compared to benchmark results from Pb‐based (Sn36Pb2Ag) PV cells. Accelerated thermal cycling tests have been conducted on PV cells of both solder compositions, and the increase in series resistance due to interconnect damage has been characterized usingin situdarkI–Vmeasurements. Both the Pb‐free and Pb‐based cells show a steep initial rise followed by a steady rate of increase in degradation histories, with the Pb‐free cells showing a more pronounced ‘knee’ in the degradation curves. Extrapolation of the degradation data for both solders suggests that Pb‐free cells are four times more durable than the Pb‐based cells at the test condition. This superior thermal cycling fatigue durability of Pb‐free cells was also confirmed with physics of failure (PoF) analysis, consisting of nonlinear finite element (FE) stress analysis and an energy‐partitioning (E‐P) solder fatigue model. FE models error‐seeded with manufacturing voids in the solder interconnect predicted a significant reduction in the thermal cycling durability with increasing solder void density. However, even the most voided Pb‐free cells modeled are predicted to be twice as durable as void‐free Pb‐based cells, under the accelerated temperature cycle used in the test. The acceleration factor (AF) predicted by the PoF analysis for a typical service environment is three times higher for Pb‐free cells than that for Pb‐based cells. Copyright © 2010 John Wiley & Sons, Ltd.
The use of Ti meshes with self‐organized TiO2 nanotubes as photoanodes of all‐Ti dye‐sensitized solar cells
Authors: Wang Yuanhao , Yang Hongxing , Liu Yong , Wang Hai , Shen Hui , Yan Jin , Xu Hongmei
Published: March 2010

This paper reports a simple and facile method for directly growing self‐organized TiO2 nanotubular arrays around the whole Ti mesh by electrochemical anodization in organic electrolytes and their application in all‐Ti dye‐sensitized solar cells (DSSCs). Compared with the traditional fluorine‐doped tin oxide (FTO)‐based DSSC and the backside illuminated DSSC, this type of DSSC showed advantages such as low resistance, cheap fabrication cost and enhanced sunlight utilization. Different thicknesses of nanotubular array layers were investigated to find their influence on the photovoltaic parameters of the cell. We also considered three types of meshes as the substrates of anodes and found that the cell with 6 openings/mm2 exhibited the highest conversion efficiency of 5.3%. The area of the cell had only a little impact on the photovoltaic performances. Copyright © 2010 John Wiley & Sons, Ltd.
ZnO nanorod arrays as an antireflective coating for Cu(In,Ga)Se2 thin film solar cells
Authors: Aé L. , Kieven D. , Chen J. , Klenk R. , Rissom Th. , Tang Y. , Lux‐Steiner M. Ch.
Published: March 2010

A ZnO nanorod antireflective coating has been prepared on Cu(In,Ga)Se2 thin film solar cells. This coating leads to a decrease of the weighted global reflectance of the solar cells from 8.6 to 3.5%. It boosts the solar cells short‐circuit current up to 5.7% without significant effect on their open‐circuit voltage and fill factor (FF), which is comparable to a conventional optimized single layer MgF2 antireflective coating. The ZnO nanorod antireflective coating was electrochemically prepared from an aqueous solution at 80°C. The antireflective capability of ZnO nanorod arrays (ZNAs) may be further improved by optimization of growth conditions and their geometry. Copyright © 2010 John Wiley & Sons, Ltd.
Improved fill factor and open circuit voltage by crystalline selenium at the Cu(In,Ga)Se2/buffer layer interface in thin film solar cells
Authors: Platzer‐Björkman C. , Zabierowski P. , Pettersson J. , Törndahl T. , Edoff M.
Published: March 2010

A surface treatment by evaporated selenium on Cu(In,Ga)Se2 (CIGS) is shown to improve open circuit voltage, Voc, and in some cases fill factor, FF, in solar cells with CdS, (Zn,Mg)O or Zn(O,S) buffer layers. Voc increases with increasing amount of crystalline Se, while FF improves only for small amounts. The improvements are counteracted by a decreasing short circuit current assigned to absorption in hexagonal Se. Improved efficiency is shown for device structures with (Zn,Mg)O and Zn(O,S) buffer layers by atomic layer deposition. Analysis by grazing incidence X‐ray diffraction and photoelectron spectroscopy show partial coverage of the CIGS surface by hexagonal selenium. The effects on device performance from replacing part of the CIGS/buffer interface area by a Se/buffer junction are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Sustainability of PV water pumping programmes: 12‐years of successful experience
Authors: Narvarte L. , Lorenzo E.
Published: March 2010

This paper presents the key points to assure the sustainability of a PV water pumping program that has supplied 5 million m3 of water in the last 12 years to approximately 40 000 people. Key aspects for success have been the proper consideration of user's priorities, rigorous technical quality assurance, and maintenance structure set up. The present work mainly focuses on the maintenance structure aspects: some results to characterize the maintenance carried out, such as the mean time to failure parameter (MTTF) or the failure typology, are shown. Copyright © 2010 John Wiley & Sons, Ltd.
An ice machine adapted into an autonomous photovoltaic system without batteries using a variable‐speed drive
Authors: Driemeier C. , Zilles R.
Published: March 2010

The adaptation of a commercially available ice machine for autonomous photovoltaic operation without batteries is presented. In this adaptation a 1040 Wp photovoltaic array directly feeds a variable‐speed drive and a 24 Vdc source. The drive runs an induction motor coupled by belt‐and‐pulley to an open reciprocating compressor, while the dc source supplies a solenoid valve and the control electronics. Motor speed and refrigerant evaporation pressure are set aiming at continuously matching system power demand to photovoltaic power availability. The resulting system is a simple integration of robust, standard, readily available parts. It produces 27 kg of ice in a clear‐sky day and has ice production costs around US$0.30/kg. Although a few machine features might be specific to Brazil, its technical and economical guidelines are applicable elsewhere. Copyright © 2010 John Wiley & Sons, Ltd.
High‐quality multi‐crystalline silicon growth for solar cells by grain‐controlled directional solidification
Authors: Yeh K. M. , Hseih C.K. , Hsu W. C. , Lan C.W.
Published: March 2010

We report simple ideas for grain control by using active cooling and crucible insulation for high‐quality multi‐crystalline silicon (mc‐Si) growth for solar cells. The method employed an active cooling spot to induce initial dendrite growth, and the solidification front was controlled to be slightly convex through crucible insulation. It was found that the percentage of grains having twins was significantly increased by the present approach. The dislocation density for those grains was also significantly lower. More importantly, the successful improvement showed that the grain size and the minority carrier lifetime increased along the growth direction. And the laser beam induced current (LBIC) measurement also showed much higher quantum efficiency for the twin area. Copyright © 2010 John Wiley & Sons, Ltd.
Determination of the bulk lifetime of bare multicrystalline silicon wafers
Authors: Bothe K. , Krain R. , Falster R. , Sinton R.
Published: March 2010

The determination of the bulk lifetime of bare multicrystalline silicon wafers without the need of surface passivation is a desirable goal. The implementation of an in‐line carrier lifetime analysis is only of benefit if the measurements can be done on bare unprocessed wafers and if the measured effective lifetime is clearly related to the bulk lifetime of the wafer. In this work, we present a detailed experimental study demonstrating the relationship between the effective carrier lifetime of unpassivated wafers and their bulk carrier lifetime. Numerical modelling is used to describe this relationship for different surface conditions taking into account the impact of a saw damage layers with poor electronic quality. Our results show that a prediction of the bulk lifetime from measurements on bare wafers is possible. Based on these results we suggest a simple procedure to implement the analysis for in‐line inspection. Copyright © 2010 John Wiley & Sons, Ltd.
Comprehensive reading instruction for students with intellectual disabilities: Findings from the first three years of a longitudinal study
Authors: Allor Jill H. , Mathes Patricia G. , Roberts J. Kyle , Cheatham Jennifer P. , Champlin Tammi M.
Published: March 2010

This longitudinal experimental study investigated the reading progress of students with IQs ranging from 40 to 69 (i.e., range for students with mild or moderate mental retardation or intellectual disabilities [ID]) across at least two academic years, as well as the effectiveness of a comprehensive reading intervention for these students across the same period of time. Participants were 59 elementary students who were randomly placed into treatment and contrast groups. Students in the treatment condition received daily, comprehensive reading instruction in small groups of 1–4 students for 40–50 minutes per session across two or three academic years. Measures of phonemic awareness, phonics, word recognition, comprehension, and oral language were included. Findings indicate that students with IQs in the ID range made significant progress on multiple standardized measures of reading. Furthermore, significant differences between the treatment group and contrast group were found on several measures, including progress‐monitoring measures of phoneme segmentation, phonics, and oral reading fluency. Results demonstrate that, on average, students with ID, even those with IQs in the moderate range, learn basic reading skills given consistent, explicit, and comprehensive reading instruction across an extended period of time. © 2010 Wiley Periodicals, Inc.