bluuebunny/crossref_metadata_2025 huggingface dataset:
Does sentinel lymph node biopsy in cutaneous head and neck melanoma alter disease outcome?
Authors: Doting Edwina H. , de Vries Mattijs , Plukker John Th.M. , Jager Piet L. , Post Wendy J. , Suurmeijer Albert J.H. , Hoekstra Harald J.
Published: May 2006

Background and Objectives

In the head and neck region, value, reliability, and safety of sentinel lymph node biopsy (SLNB) have not yet been determined conclusively. The aim of study was to assess impact of SLNB on disease outcome in cutaneous head and neck melanoma.

Methods

Thirty‐six patients with a clinically node‐negative head and neck melanoma, ≥1.0 mm Breslow thickness, participated in a prospective study from 1995 to 2005. Sentinel lymph node (SLN) tumor‐positive patients underwent completion lymphadenectomy. SLN tumor‐negative patients underwent clinical monitoring. Median follow‐up was 54 (range 10–114) months. Recurrence‐free and overall survival curves were constructed by Kaplan–Meier.

Results

SLNs could be identified in 33 patients (92%). In 7 patients (21%) the SLN was tumor‐positive. In 1 patient (13%) the SLNB was false‐negative. In 17 patients (47%) SLNs could be identified in the parotid region (success rate parotid region 100%). This study showed no significant difference in recurrence‐free and overall survival between patients with tumor‐positive and tumor‐negative SLN.

Conclusions

The safety and accuracy of SLNB in the neck and parotid nodal basins were similar to those in non‐head and neck sites. However, the technique is technically demanding in this region. In this small series SLNB did not alter disease outcome. J. Surg. Oncol. 2006;93:564–570. © 2006 Wiley‐Liss, Inc.
Rapid identification of Escherichia coli and Helicobacter pylori in biological samples by capillary zone electrophoresis
Authors: Kłodzińska Ewa , Dahm Hanna , Róźycki Henryk , Szeliga Jacek , Jackowski Marek , Buszewski Bogusław
Published: May 2006

The differences in surface charge of different bacteria can be exploited for their separation by capillary electrophoresis. However, this method of separation of microorganisms is beset with various drawbacks such as adhesion of bacteria to the fused silica surface or cluster formation. To overcome these phenomena we investigated the addition of poly(ethylene oxide) as a focusing agent to the running buffer and used calcium and myoinositol hexakisphosphate as specific ions that interact with the bacterial surface, changing its electrical properties and electrophoretic mobilities. In the present work, we applied CZE to identification of E. coli in infected urine (direct injection) from patients with urinary tract infections and to identification of Helicobacter pylori, which is a gram‐negative bacillus responsible for one of the most common infections found in humans worldwide. Helicobacter pylori colonize the stomach and are responsible for severe diseases of the gastric tract, ranging from chronic gastric ulcer to gastric cancer.
Influence of stationary phase properties on the separation of ionic liquid cations by RP‐HPLC
Authors: Buszewski Bogusław , Kowalska Sylwia , Stepnowski Piotr
Published: May 2006

Different types of columns with specific structural properties were used for the separation of mixtures of ionic liquid cations. Two of them were home‐made packings and the other two were commercial stationary phases. One of the home‐made packings contained cholesterol ligands bonded chemically to silica (SG‐CHOL) whereas the other one was a mixed stationary phase (SG‐MIX) with cyanopropyl, aminopropyl, phenyl, octyl, and octadecyl ligands. RP‐18e Innovation ChromolithTM Performance and Macrosphere 300 C4 packings were also used. A comparison of the separation possibilities offered by these columns for the substances in question revealed significant differences in performance. Packings containing surface‐bonded functional groups that are able to undergo protonation are not suitable for separation of such compounds under the given analysis conditions (pH = 4). The best results were obtained for two alkyl stationary phases: butyl and octadecyl. Cluster analysis has also been performed for comparison of the ionic liquid cation properties.
Road construction impacts on stream suspended sediment loads in a nested catchment system in Nepal
Authors: Merz J. , Dangol P. M. , Dhakal M. P. , Dongol B. S. , Nakarmi G. , Weingartner R.
Published: May 2006

In terms of erosion and elevated suspended sediment concentrations, road construction has a major impact on the environment, which is described in this paper. In the Andheri Khola catchment, Nepal, the sediment regime of a stream at different locations within the catchment suddenly changed between 1999 and 2000. The only explanation for this change was the construction of the Bardibas‐Dhulikhel highway, which was initiated in this area in January 2000 and completed in March 2000. The changes in suspended sediment concentration could be shown both visually as well as statistically at three different locations in the catchment with a catchment without any impact of the road as a control. Other possible reasons for the change could be excluded by using the available data from the catchment. The impact of the road was estimated to range from 300 to 500 per cent in terms of change in sediment yield per annum. Copyright © 2006 John Wiley & Sons, Ltd.
An Er:YAG laser endoscopic fiber delivery system for lithotripsy of salivary stones
Authors: Raif Joshua , Vardi Michael , Nahlieli Oded , Gannot Israel
Published: May 2006

Background and Objectives

Endoscopic applications of Erbium:YAG lasers are still very limited due to lack of appropriate fiber delivery capabilities. Recent reports on potential advantages of this laser for lithotripsy of ureteral stones prompted us to develop an Er:YAG fiber delivery system for endoscopic lithotripsy of salivary stones. We report on the development of this system and its clinical use on 17 patients.

Study Design/Materials and Methods

Ho:YAG and Er:YAG laser fragmentation performances were initially compared. Optimal laser parameters for lithotripsy of salivary stones were then established ex vivo using a commercial dental Er:YAG laser (Lumenis Opusdent 20). Metal hollow waveguides optimized for Er:YAG laser transmission were end sealed with a polished sapphire rod of 0.63 mm diameter and designed to adapt to the Opusdent laser and to a Storz sialoendoscope. The system was tested ex vivo for durability and clinical compatibility at input energies up to 700 mJ, 10–20 Hz. Following Helsinki approval the system was clinically tested on 17 patients with sialolithiasis.

Results

Lithotripsy threshold was around 80 mJ/pulse (26 J/cm2) while efficient fragmentation, with microscopic fragments, was observed at an output energy range of 150–300 mJ/pulse. At 10 Hz, fragmentation rates of about 1.8 mm3/second were achieved enabling lithotripsy of a 6 mm stone in about 2 minutes. Front surface damage to the sapphire rod occurred but did not contribute to significant loss in fragmentation efficiency. Of the 21 stones treated clinically, 5 were fully fragmented, 7 were prepared for extraction by mini forceps, and 9 were released from surrounding soft tissues for subsequent removal. Fifteen of the 18 treated glands returned to normal function without any symptoms.

Conclusions

The Er:YAG endoscopic delivery system described is a clinically viable and cost‐effective device for a range of hard and soft tissue wet field applications accessible through rigid or semi‐rigid endoscopes. Further improvements in the waveguide may allow access also through fully flexible endoscopes. Lasers Surg. Med. 38:580–587, 2006. © 2006 Wiley‐Liss, Inc.
Analysis of pesticides in water by liquid chromatography‐tandem mass spectrometric techniques
Authors: Kuster Marina , de Alda Maria López , Barceló Damià
Published: May 2006

Pesticide residues continue to be the focus of many environmental studies, and the number of articles describing the development of more advanced, multiresidue analytical methodologies does not decline. The use of liquid chromatography‐mass spectrometry based on single quadrupole or ion trap analyzers is consolidated for this purpose. The implementation, in the near future, of more sophisticated mass analyzers, such as triple quadrupole and hybrid quadrupole‐time‐of‐flight is anticipated for routine analysis. This article reviews the various works published so far in the literature for the determination of pesticides and transformation products (TPs) in water by means of liquid chromatography (LC) coupled to tandem mass spectrometry. It discusses the various ionization sources and analyzers used for this purpose, as well as the extraction procedures employed for previous sample preconcentration. Because of the widespread use of triple quadrupole analyzers for the generation of pesticides levels in water using tandem mass spectrometry, a table compiling the transitions monitored for ca. 70 compounds is also included. © 2006 Wiley Periodicals, Inc.
Association between amantadine and the onset of dementia in Parkinson's disease
Authors: Inzelberg Rivka , Bonuccelli Ubaldo , Schechtman Edna , Miniowich Ala , Strugatsky Rosa , Ceravolo Roberto , Logi Chiara , Rossi Carlo , Klein Colin , Rabey J. Martin
Published: May 2006

The objective of this study is to compare the occurrence of dementia among Parkinson's disease (PD) patients treated with amantadine (AM group) with those never exposed to it (NoAM group). PD dementia shares neuroanatomical and biochemical similarities with Alzheimer's disease (AD). Memantine, an N‐methyl‐D‐aspartate (NMDA) receptor antagonist has been shown to be beneficial in AD. Memantine is a dimethyl derivative of amantadine, which also possesses NMDA receptor blocking properties. We hypothesized that amantadine could have a beneficial effect on the occurrence of PD dementia. PD patients attending the Movement Disorders Clinics in Hillel Yaffe, Asaf Harofe Medical Centers (Israel) and Pisa (Italy) were included. Taking the onset of dementia as the endpoint, survival curves for AM and NoAM patients were estimated by the Kaplan–Meier method. The study population consisted of 593 patients (age, 69.5 ± 9.9 years; PD duration, 9.2 ± 6.0 years; 263 patients (44%) amantadine treated). The endpoint of dementia was reached by 116 patients (20%). PD duration until dementia was significantly longer for AM patients (9.1 ± 5.7 years) than for NoAM patients (5.9 ± 4.6 years, P = 0.006). The duration of amantadine exposure positively correlated with PD duration until dementia (P = 0.0001). Survival analysis, taking dementia onset as endpoint, showed slower mental decline in AM patients (Log rank P = 0.0049, Wilcoxon P = 0.0024). Mini‐Mental State Examination scores were significantly higher for AM patients than for the NoAM group (P = 0.01). Age of PD onset also significantly influenced the duration of PD until dementia. Amantadine use may delay the onset of dementia in PD patients and may attenuate its severity. © 2006 Movement Disorder Society
Methylphenidate fails to improve gait and muscle tone in patients with sporadic and hereditary spastic paraplegia
Authors: Klebe Stephan , Deuschl Günther , Stolze Henning
Published: May 2006

Based on its action on multiple neurotransmitters, including dopamine, methylphenidate (MPH) is of growing interest as a possible treatment option for several movement disorders. Of special interest are diseases that share gait disturbance and cognitive decline. Based on a single case observation in a patient with hereditary spastic spinal paraplegia (HSP) in which gait was improved with MPH, we performed an open‐label study with a longitudinal follow‐up in 22 patients with HSP and its sporadic form (SSP). The patients were treated for 6 months with 60 mg of MPH per day. Computerized gait analysis and different scores were performed at baseline, after 6 weeks, and after 6 months of treatment. Although at 6 weeks, the gait velocity was somewhat improved, the drug failed to show any effect on other gait parameters and had no beneficial effect at all after 6 months. Although MPH is of interest for several movement disorders, our study did not show a beneficial effect. © 2006 Movement Disorder Society
Structure and intramolecular flexibility of β‐cyclodextrin complex with (−)‐epigallocatechin gallate in aqueous solvent
Authors: Ishizu Takashi , Hirata Chikako , Yamamoto Hideji , Harano Kazunobu
Published: May 2006

The probable structure of the inclusion complex of β‐cyclodextrin (β‐CD) and (−)‐epigallocatechin gallate (EGCg) in D2O was investigated using several NMR techniques. EGCg formed a 1:1 complex with β‐CD, in which the A ring and a portion of the C ring of EGCg were included at the head of the phenolic hydroxyl group attached to C7 of EGCg in the β‐CD cavity from the wide secondary hydroxyl group side. In the 1:1 complex with β‐CD, EGCg maintained the conformation in which the B and B′ rings of EGCg took pseudoequatorial and pseudoaxial positions with respect to the C ring, respectively. The structure of the inclusion complexes of β‐CD and EGCg obtained from NMR experiments supported those determined from AM1 semiempirical SCF MO calculations well. Copyright © 2006 John Wiley & Sons, Ltd.
Capillary morphogenesis gene (CMG)‐1 is among the genes differentially expressed in mouse male germ line stem cells and embryonic stem cells
Authors: Fujino Ryu‐Suke , Ishikawa Yu‐Ichiro , Tanaka Kiyoko , Kanatsu‐Shinohara Mito , Tamura Kazuhiro , Kogo Hiroshi , Shinohara Takashi , Hara Takahiko
Published: May 2006

We recently established a technique to expand male germ line stem (GS) cells in long‐term culture without losing their spermatogenic capacity. To gain insight into the genetic program of these cells, we compared the mRNA expression profile of GS cells with that of embryonic stem (ES) cells using DNA microarrays. We found 79 genes that were upregulated in GS cells compared to ES cells, including synaptonemal complex protein‐1, deleted in azoospermia‐like, ubiquitin‐conjugating enzyme E2B, and ubiquitin carboxy‐terminal hydrolase L1, all of which are functionally important for spermatogenesis. In addition, we identified a cDNA encoding the mouse ortholog of capillary morphogenesis gene (CMG)‐1. CMG‐1 transcripts were predominantly produced in spermatogonia and spermatocytes in mouse testis. When CMG‐1 expression was attenuated in a mouse spermatocyte‐derived cell line, GC‐2spd(ts), by a target‐specific short interfering RNA, the morphology of the cells was changed and the expression of cyclin D2 was abrogated. A reporter assay using a genomic region upstream of the mouse cyclin D2 gene revealed that this downmodulation occurs at the transcriptional level. We detected FLAG‐tagged CMG‐1 protein in the nuclei of transfected COS7 cells, suggesting that CMG‐1 may play a unique role in the transcriptional regulation of the cyclin D2 gene. The upregulated GS genes identified in this study will provide useful information for the future investigation of spermatogonial stem cells and the early phase of male germ cell differentiation. Mol. Reprod. Dev. 955–966, 2006. © 2006 Wiley‐Liss, Inc.
Object‐oriented finite element analysis of thermo‐hydro‐mechanical (THM) problems in porous media
Authors: Wang Wenqing , Kolditz Olaf
Published: May 2006

The design, implementation and application of a concept for object‐oriented in finite element analysis of multi‐field problems is presented in this paper. The basic idea of this concept is that the underlying governing equations of porous media mechanics can be classified into different types of partial differential equations (PDEs). In principle, similar types of PDEs for diverse physical problems differ only in material coefficients. Local element matrices and vectors arising from the finite element discretization of the PDEs are categorized into several types, regardless of which physical problem they belong to (i.e. fluid flow, mass and heat transport or deformation processes). Element (ELE) objects are introduced to carry out the local assembly of the algebraic equations. The object‐orientation includes a strict encapsulation of geometrical (GEO), topological (MSH), process‐related (FEM) data and methods of element objects. Geometric entities of an element such as nodes, edges, faces and neighbours are abstracted into corresponding geometric element objects (ELE–GEO). The relationships among these geometric entities form the topology of element meshes (ELE–MSH). Finite element objects (ELE–FEM) are presented for the local element calculations, in which each classification type of the matrices and vectors is computed by a unique function. These element functions are able to deal with different element types (lines, triangles, quadrilaterals, tetrahedra, prisms, hexahedra) by automatically choosing the related element interpolation functions. For each process of a multi‐field problem, only a single instance of the finite element object is required. The element objects provide a flexible coding environment for multi‐field problems with different element types. Here, the C++ implementations of the objects are given and described in detail. The efficiency of the new element objects is demonstrated by several test cases dealing with thermo‐hydro‐mechanical (THM) coupled problems for geotechnical applications. Copyright © 2006 John Wiley & Sons, Ltd.
On the physics of block copolymers
Authors: Lecommandoux S , Borsali R
Published: May 2006

This article highlights some original block copolymer properties that have been studied in recent years at the Physico‐Chemistry group at the LCPO, giving our view on the physics of block copolymers in solutions (disordered state and self‐assembly) and in the bulk (nano‐organized films). In particular, we show that beyond the classical results on flexible–flexible block copolymer chains, the architecture (rigidity of the blocks, cyclization, etc) as well as external parameters (temperature, pH, ionic strength) play an important role in the different phases of a material made from block copolymers with controlled architectures. The properties of the various block copolymer systems investigated, in aqueous or organic media, are discussed in terms of free block copolymer chains, self‐assemblies and nano‐structured/nano‐organized films with the aid of techniques such as scattering (light, X‐rays, neutrons) and imaging (AFM, TEM). Copyright © 2006 Society of Chemical Industry
Origin of the methylene bonds in poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] prepared according to Gilch's method: novel applications
Authors: Lin King‐Fu , Fan Yang‐Liang , Chow Hsuan‐Liang
Published: May 2006

Impurities containing methylene bridges between 2‐((2′‐ethylhexyl)oxy)‐5‐methoxy‐benzene molecules are inevitably formed during the synthesis of 1,4‐bis(chloromethyl)‐2‐((2′‐ethylhexyl)oxy)‐5‐methoxy‐benzene, the monomer used in the preparation of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV), but they can be removed by double recrystallization of the monomer prior to polymerization. When impurities containing methylene bridges participate in a Gilch polymerization, the methylene bonds formed in the main chains are prone to break at 200 °C, that is, at least 150 °C below the major degradation temperature of defect‐free MEH‐PPV. Interestingly, the thermal treatment used to break the methylene bonds present reduces the chain aggregation of MEH‐PPV during film formation and induces its blends with poly(2,3‐diphenyl‐5‐octyl‐p‐phenylene‐vinylene) (DPO‐PPV) to form a morphology similar to that of block copolymers. Both significantly enhance the luminescence properties. Copyright © 2006 Society of Chemical Industry
Small angle neutron scattering study of the structure and hydration of polyoxyethylene‐block‐polyoxybutylene in aqueous solution
Authors: Fairclough J Patrick A , Norman Alexander Iain , Shaw Benjamin , Nace V Mark , Heenan Richard K
Published: May 2006

The micellar structure of a polyoxyethylene‐block‐polyoxybutylene diblock copolymer (E18B10; E = (OCH2CH2); B = OCH2CH(CH2CH3)) in water was studied by small angle neutron scattering. Results show a polydisperse spherical micelles at temperatures below 45 °C, a possible mixed phase at 45 °C and flexible worm‐like micelles at 65 °C. The spherical micelles at 25 and 35 °C have radii of 39 and 40 Å and degrees of hydration of 28% and 26%, respectively. The worm‐like micelles have a total length of approximately 1850 Å, with segment lengths of 123 Å, a core radius, Rax = 30 Å and hydration of 23%, at 65 °C. Copyright © 2006 Society of Chemical Industry
Bi‐axial self‐reinforcement of high‐density polyethylene induced by high‐molecular weight polyethylene through dynamic packing injection molding
Authors: Lei Jun , Zhang Zhenjun , Jiang Chaodong , Shen Kaizhi
Published: May 2006

Previously, bi‐axial self‐reinforcement of high‐density polyethylene (HDPE) was achieved through a uni‐axial shear stress field introduced by dynamic packing injection molding technology. Here, further improvement of tensile strength along the flow direction (MD) was achieved by blending a small amount of high‐molecular‐weight polyethylene (HMWPE) with HDPE, while the tensile strength along the transverse direction (TD) still substantially exceeded that of conventional moldings. Tensile strengths in both flow and transverse directions were considerably enhanced, with improvements from 23 MPa to 76 MPa in MD and from 23 MPa to 31 MPa in TD. The effect of HMWPE content and molding parameters on tensile properties was also investigated. The tensile strength along MD was highly dependent on HMWPE content, oscillating cycle, mold temperature, melt temperature and packing pressure, while that along TD was insensitive to composition and processing parameters within the selected design space. According to the stress–strain curves, samples with HMWPE produced by dynamic packing injection molding had a special tensile failure mode in MD, different from both typical plastic and brittle failure modes. There were no yielding and necking phenomena, which are characteristic during tensile testing of plastic materials, but there was still a considerably higher elongation compared to those of brittle materials. However, in TD, all dynamic injection molding samples exhibited plastic failure as did typical conventional injection molding samples. Copyright © 2006 Society of Chemical Industry
Preparation and characterization of polydiphenylamine/multi‐walled carbon nanotube composites
Authors: Lu Xiaofeng , Chao Danming , Zheng Jiani , Chen Jingyu , Zhang Wanjin , Wei Yen
Published: May 2006

We describe the synthesis of methane sulfonic acid (MeSA)‐doped poly(diphenylamine) (PDPA) with carboxylic groups containing multi‐walled carbon nanotubes (c‐MWNTs) via in situ polymerization. Diphenylamine monomers were adsorbed on to the surface of c‐MWNTs and polymerized to form PDPA/c‐MWNT composites. SEM and TEM images indicated two different types of materials: the thinner fibrous phase and the larger globular phase. The individual fibrous phase had a diameter around 100–130 nm, which should be the carbon nanotubes (diameter 20–30 nm) coated with a PDPA layer. The structure of PDPA/c‐MWNT composites was characterized by FTIR, UV‐visible spectroscopy and X‐ray diffraction patterns. The electrical conductivities of PDPA/c‐MWNT composites were much higher than that of PDPA without c‐MWNTs. Copyright © 2006 Society of Chemical Industry
Synthesis and characterization of crosslinkable latex with interpenetrating network structure based on polystyrene and polyacrylate
Authors: Zhang Ji‐De , Yang Mu‐Jie , Zhu Yang‐Rong , Yang Huan
Published: May 2006

Functional poly[styrene‐co‐(2‐ethylhexyl acrylate)‐co‐(1,6‐hexanediol diacrylate)]/poly[(methyl methacrylate)‐co‐(butyl acrylate)‐co‐(methacrylic acid)‐co‐(diacetone acrylamide)] (PS/PA) semi‐interpenetrating polymer networks (semi‐LIPNs) containing ketone carboxyl groups were synthesized by two‐stage emulsion polymerization, and characterized by Fourier transform infrared, transmission electron microscopy, dynamic light scattering and DSC. A unique feature of the PS/PA semi‐LIPNs is their ability to crosslink and form thermosetting full‐IPN polymers through the reaction of ketone carboxyl and hydrazide in the course of film formation at ambient temperatures. Series of latex particles with various levels of crosslinking density in the PS and PA domain and varied composition of PS/PA LIPNs were obtained. The effects of the LIPN PS/PA composition and the level of crosslinking density in the PS and PA domain on film density, swell ratio, mechanical properties and contact angle with water were investigated. Maximum synergy effects obtained at around 50/50 (PS/PA) in terms of mechanical properties, density and contact angle with water indicate that the maximum degree of interpenetration is obtained at this composition. Copyright © 2006 Society of Chemical Industry
Contact wetting angle as a characterization technique for processing CdTe/CdS solar cells
Authors: Angelo M. S. , McCandless B. E. , Birkmire R. W. , Rykov S. A. , Chen J. G.
Published: May 2006

The feasibility of measuring contact wetting angles to characterize processing induced changes to thin film semiconductors in CdTe/CdS solar cells is evaluated. The contact angles of water and formamide are used to determine the polar and dispersive surface energies of the thin films using two analysis methods. Changes in surface energies resulting from processing are correlated to changes in surface chemistry and structure detected by glancing incidence X‐ray diffraction (GIXRD), X‐ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Surface energies are evaluated for sputtered In2O3:SnO2, chemical surface‐deposited CdS, and physical vapor‐deposited (PVD) CdTe thin films under as‐deposited and treated conditions. Treatments include thermal anneal in air, argon, and CdCl2ambient as well as surface etching. Indium tin oxide (ITO) and CdS films exhibit increased polar surface energy corresponding to enhanced crystallization of surfaces resulting from processing and increasing CdS growth temperature. Native oxidation of PVD CdTe (111)‐oriented film surfaces occurs rapidly and is readily detected by changes in contact angle. Surface energies of PVD (111)‐oriented CdTe stored under various humidities prior to processing are energetically similar due to native oxidation. The polar energy of CdTe surfaces is affected by the addition or removal of crystalline surface oxides during film processing. Copyright © 2006 John Wiley & Sons, Ltd.
A simulation‐based method for the comprehensive analysis of effective lifetime from photoconductance
Authors: Bueno G. , Recart F. , Jimeno J. C.
Published: May 2006

This paper presents a method for estimating recombination parameters in the volume and surface of solar cell precursors throughout the manufacturing process, taking into account several effects that are generally neglected. The technique is based on the comprehensive reconstruction of the effective lifetime assuming a set of fundamental parameters and its comparison to the experimental data obtained from the photoconductance measured under uniform generation in quasi‐steady state conditions. The analysis starts from the semianalytical solution of the minority carrier profiles in the structures under test. This analysis overcomes the usual flat profile approximation and presents important advantages. It allows the asymmetry presented by the solar cell precursors to be taken into account and deals with a wide range of surface conditions: emitters, bare silicon or dielectric passivations. The model also accounts for the effect of the electric field in the volume, and implements several phenomena that are sometimes neglected but are relevant when measuring industrial solar cells precursors: the injection dependence of mobilities and recombination lifetimes, the presence of non‐recombinant traps and the Depletion Region Modulation effect. The estimation technique requires uniform generation, which greatly facilitates the calculation of the carrier profiles and allows for a simple method for the auto calibration of the light absorption. Copyright © 2006 John Wiley & Sons, Ltd.
Effective efficiency of PV modules under field conditions
Authors: Topi Marko , Brecl Kristijan , Sites James
Published: May 2006

The conversion efficiency of photovoltaic modules varies with irradiance and temperature in a predictable fashion, and hence the effective efficiency averaged over a year under field conditions can be reliably assessed. The suggested procedure is to define the efficiency versus irradiance and temperature for a specific module, collect the local irradiance and temperature data, and combine the two mathematically, resulting in effective efficiency. Reasonable approximations simplify the process. The module performance ratio is defined to be the ratio of effective efficiency to that under standard test conditions. Variations of the order of 10% in this factor among manufacturers, primarily the result of the differences in effective series resistance and leakage conductance, are not unusual. A focus on these parameters that control the effective efficiency should provide a path to PV modules with improved field performance. Copyright © 2006 John Wiley & Sons, Ltd.
Dependability analysis of stand‐alone photovoltaic systems
Authors: Díaz Pablo , Egido Miguel Ángel , Nieuwenhout Frans
Published: May 2006

Long‐term performance of PV stand‐alone systems is analysed in this work in terms of dependability. On one side, the quality of a PV system, the energy service supplied to the users, depends on the initial design and sizing and on the component ageing that progressively decreases the availability of supply on demand (energy reliability). On the other side, technical failures lead to system stoppage until repairing is performed (technical reliability), which is crucial in real rural electrification applications. All those factors are analysed together with the basis of an extended field, laboratory and bibliographic review work. Copyright © 2006 John Wiley & Sons, Ltd.
Amino acid substitutions affecting protein dynamics in eglin C do not affect heat capacity change upon unfolding
Authors: Gribenko Alexey V. , Keiffer Timothy R. , Makhatadze George I.
Published: May 2006

The heat capacity change upon unfolding (ΔCp) is a thermodynamic parameter that defines the temperature dependence of the thermodynamic stability of proteins; however, physical basis of the heat capacity change is not completely understood. Although empirical surface area‐based calculations can predict heat capacity changes reasonably well, accumulating evidence suggests that changes in hydration of those surfaces is not the only parameter contributing to the observed heat capacity changes upon unfolding. Because packing density in the protein interior is similar to that observed in organic crystals, we hypothesized that changes in protein dynamics resulting in increased rigidity of the protein structure might contribute to the observed heat capacity change upon unfolding. Using differential scanning calorimetry we characterized the thermodynamic behavior of a serine protease inhibitor eglin C and two eglin C variants with altered native state dynamics, as determined by NMR. We found no evidence of changes in ΔCp in either of the variants, suggesting that changes in rigidity do not contribute to the heat capacity change upon unfolding in this model system. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Dynamic control of allosteric antagonism of leukocyte function antigen‐1 and intercellular adhesion molecule‐1 interaction
Authors: Nam Kiyean , Maiorov Vladimir , Feuston Bradley , Kearsley Simon
Published: May 2006

Leukocyte function associated antigen‐1 (LFA‐1) plays a critical role in T cell migration and has been recognized as a therapeutic target for immune disorders. Several classes of small molecule antagonists have been developed to block LFA‐1 interaction with intercellular adhesion molecule‐1 (ICAM‐1). Recent structural studies show that the antagonists bind to an allosteric site in the I‐domain of LFA‐1. However, it is not yet clear how these small molecules work as antagonists since no significant conformational change is observed in the I‐domain–antagonist complex structures. Here we present a computational study suggesting how these allosteric antagonists affect the dynamics of the I‐domain. The lowest frequency vibrational mode calculated from an LFA‐1 I‐domain structure shows large scale “coil‐down” motion of the C‐terminal α7 helix, which may lead to the open form of the I‐domain. The presence of an allosteric antagonist greatly reduces this motion of the α7 helix as well as other parts of the I‐domain. Thus, our study suggests that allosteric antagonists work by eliminating breathing motion that leads to the open conformation of the I‐domain. Proteins 2006. © 2006 Wiley‐Liss, Inc.
The antifouling activity of some juvenoids on three species of acorn barnacle, Balanus
Authors: Skattebøl Lars , Nilsen Nils Olav , Stenstrøm Yngve , Andreassen Petter , Willemsen Peter
Published: May 2006

Analogues of insect juvenile hormones (juvenoids) have been tested for settling inhibition of cyprids from three species of barnacle, Balanus balanoides (L.), Balanus improvisus Darwin and Balanus amphitrite Darwin. Some 3‐alkoxypyridine derivatives exhibited strong activity at mg litre−1 concentrations; 3,7‐dimethyloctyl 2‐methyl‐5‐pyridyl ether (8) gave an EC50 of 0.006 mg litre−1 when tested on B. balanoides. When compound 8 and similar juvenoids were incorporated into paints, test panels kept in seawater for 8 months were free of barnacles. Copyright © 2006 Society of Chemical Industry
2D and 3D Quantitative Structure‐Activity Relationship Studies on a Series of bis‐Pyridinium Compounds as Choline Kinase Inhibitors
Authors: Janardhan S. , Srivani P. , Sastry G. Narahari
Published: May 2006

Two‐dimensional (2D) and three‐dimensional (3D) quantitative structure activity relationship (QSAR) studies have been carried out on a series of 55 bis‐pyridinium compounds to find out the structural requirements of choline kinase (ChoK) inhibitors. The best predictions were obtained from the model where 44 compounds were considered in the training set and the remaining 11 in the test set. The heuristic and BMLR methods resulted with r2 and q2 values of 0.86, 0.83 and 0.87, 0.84 respectively. The obtained Fisher and S2 values for both the methods are 49.02 and 54.05, 0.053 and 0.0397 respectively. The best model for 3D‐QSAR has been obtained with r2=0.97, q2 = 0.58 and r$\rm{ {_{pred}^{2}}}$=0.68 when CoMFA fields were used. The r2 of 0.85, q2 of 0.55 and r$\rm{ {_{pred}^{2}}}$=0.66 have been observed when CoMSIA fields were used. The results that are obtained from 2D and 3D‐QSAR studies may provide useful insights into the roles of various substitution patterns on the bis‐pyridinium skeleton and may also help to design more potent compounds.
Utility of porous graphitic carbon stationary phase in quantitative liquid chromatography/tandem mass spectrometry bioanalysis: quantitation of diastereomers in plasma
Authors: Xia Yuan‐Qing , Jemal Mohammed , Zheng Naiyu , Shen Xiaohang
Published: May 2006

A major challenge in selecting an appropriate stationary phase for diastereomeric separation is that it is difficult to predict which of the commercially available stationary phases could achieve the required liquid chromatographic (LC) separation. This work describes the selection and evaluation of a porous graphitic carbon (PGC) column coupled with tandem mass spectrometry (MS/MS) for the simultaneous quantitation of an experimental drug candidate (I), its two diastereomeric metabolites (II and III), and its demethylated metabolite (IV) in rat plasma. In addition, we investigated the PGC column for the separation of another drug candidate (VI), its two diastereomeric metabolites (VII and VIII) and its ketone metabolite (IX). The PGC column showed excellent chromatographic resolution for the two diastereomers II and III, as well as for VII and VIII. In contrast, the required resolution for the diastereomers II and III could not be achieved using silica‐bonded C18, C30, phenyl, perfluorinated, polar embedded and polar end‐capped phases. The PGC column showed ruggedness with excellent reproducibility of retention times, peak symmetry and response over a period of more than 400 injections of a plasma acetonitrile‐precipitation extract. Excellent accuracy and precision were achieved, with accuracy of 94–108% and intra‐ and inter‐run precision within 9%. This work indicates that PGC is a valuable addition to the repertoire of LC columns used for quantitative LC/MS/MS bioanalysis, especially where the separation and quantitation of diastereomeric analytes is involved. Copyright © 2006 John Wiley & Sons, Ltd.
Fixation of nitrogen in an electrospray mass spectrometer
Authors: Levine Rodney L.
Published: May 2006

The formation of an iron‐nitrogen compound in an electrospray ionization instrument is reported. The iron was released from the stainless steel electrospray needle by acetic acid added to displace trifluoroacetic acid and the nitrogen was present as the drying gas. The product is an iron nitride ion, [N2FeOH]1+, m/z 100.9438, and is capable of addition to peptides and proteins. Published in 2006 by John Wiley & Sons, Ltd.
Combined infrared multiphoton dissociation and electron‐capture dissociation using co‐linear and overlapping beams in Fourier transform ion cyclotron resonance mass spectrometry
Authors: Mihalca Romulus , van der Burgt Yuri E. M. , McDonnell Liam A. , Duursma Marc , Cerjak Iliya , Heck Albert J. R. , Heeren Ron M. A.
Published: May 2006

A novel set‐up for Fourier transform ion cyclotron resonance mass spectrometry (FTICR) is reported for simultaneous infrared multiphoton dissociation (IRMPD) and electron‐capture dissociation (ECD). An unmodified electron gun ensures complete, on‐axis overlap between the electron and the photon beams. The instrumentation, design and implementation of this novel approach are described. In this configuration the IR beam is directed into the ICR cell using a pneumatically actuated mirror inserted into the ion‐optical path. Concept validation was made using different combinations of IRMPD and ECD irradiation events on two standard peptides. The ability to perform efficient IRMPD, ECD and especially simultaneous IRMPD and ECD using lower irradiation times is demonstrated. The increase in primary sequence coverage, with the combined IRMPD and ECD set‐up, also increases the confidence in peptide and protein assignments. Copyright © 2006 John Wiley & Sons, Ltd.
N‐terminal H3/D3‐acetylation for improved high‐throughput peptide sequencing by matrix‐assisted laser desorption/ionization mass spectrometry with a time‐of‐flight/time‐of‐flight analyzer
Authors: Noga Marek J. , Asperger Arndt , Silberring Jerzy
Published: May 2006

A novel method for peptide sequencing by matrix‐assisted laser desorption/ionization mass spectrometry with a time‐of‐flight/time‐of‐flight analyzer (MALDI‐TOF/TOF) is presented. A stable isotope label introduced in the peptide N‐terminus by derivatization, using a 1:1 mixture of acetic anhydride and deuterated acetic anhydride, allows for easy and unambiguous identification of ions belonging either to the N‐ or the C‐terminal ion series in the product ion spectrum, making sequence assignment significantly simplified. The good performance of this technique was shown by successful sequencing of the contents of several peptide maps. A similar approach was recently applied to nanoelectrospray ionization (nanoESI) and nano‐liquid chromatography/tandem mass spectrometry (LC/MS/MS). The MALDI‐TOF/TOF technique allows for fast, direct sequencing of modified peptides in proteomics samples, and is complementary to the nanoESI and nanoLC/MS/MS approaches. Copyright © 2006 John Wiley & Sons, Ltd.
Detection of 17α‐hydroxyprogesterone caproate in equine plasma by gas chromatography/tandem mass spectrometry
Authors: McKinney Andrew R. , Suann Craig J. , Stenhouse Allen M.
Published: May 2006

A method was developed for the analysis of the synthetic progestin 17α‐hydroxyprogesterone caproate in equine plasma following its administration by intramuscular injection. The method employed a reversed‐phase solid‐phase extraction followed by enol‐trimethylsilylation and analysis by gas chromatography/tandem mass spectrometry. The intact ester was detectable in the plasma for up to 2 weeks after a single therapeutic dose, and was found to be stable in equine whole blood for at least 2 months. Copyright © 2006 John Wiley & Sons, Ltd.
Real‐time depth‐mapping three‐dimension TV camera (Axi‐Vision camera)
Authors: Kawakita Masahiro , Iizuka Keigo , Iino Yoshiki , Kikuchi Hiroshi , Fujikake Hideo , Aida Tahito
Published: May 2006

A three‐dimension camera (Axi‐Vision camera) has been developed that is capable of producing a color image of an object and performing high‐speed mapping of depth information from the camera to the object. With this camera, intensity‐modulated near‐infrared light is irradiated onto the object, and distances to points on the object are computed from the image captured by a camera that has a high‐speed shutter. Since a two‐dimensional scanning mechanism for a laser beam or complex computational processing is unnecessary in this depth mapping system, the distance to the object can be detected at high speed for each pixel of a TV image. For the present paper, a three‐dimension camera adapted to a standard television signal was constructed by development of a high‐output light‐emitting‐diode (LED) array light source capable of high‐speed intensity modulation, an image intensifier capable of high‐speed shutter operation on the nanosecond order, and an optical system. The prototype camera can output a depth image with a resolution of 768 × 493 pixels at a frame rate of 15 Hz, the characteristic depth mapping resolution of the camera is 1.8 cm (when the distance from the camera to the object is 2 m), and the camera can capture an image of a person‐sized object. It was also shown that the depth information thus obtained could be applied to live‐action filming and to CG and other new types of image synthesis. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(8): 77–89, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20320
Multi‐subregion‐based probabilistic approach to pose‐invariant face recognition
Authors: Yamada Akihiko , Kanade Takeo
Published: May 2006

Current automatic facial recognition systems are not robust to changes in illumination, pose, facial expression, and occlusion. In this paper, in order to address the problem of pose change, we propose an algorithm based on a probabilistic approach to face recognition that takes into account the pose difference between probe and gallery images. By using a large facial image database, the CMU PIE database, which contains images of the same set of people taken from many different angles, we have developed a probabilistic model of how facial features change as the pose changes. This model enables us to make our face recognition system more robust to changes of pose in the probe image. The experimental results show that this approach achieves a better recognition rate than conventional face recognition methods over a much larger range of poses. For example, when the gallery contains only images of a frontal face and the probe image varies its pose orientation, the recognition rate shows less than a 10% difference until the probe pose begins to differ by more than 45°, whereas the recognition rate of a PCA‐based method begins to drop at differences as small as 10°, and that of a representative commercial system begins to drop at 30°. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(8): 68–76, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20437
3D information access space based on multifacet database visualization
Authors: Ohigashi Makoto , Tanaka Yuzuru
Published: May 2006

In order to access target information while getting an overview of the entirety of a large‐scale database, a search must be carried out in parallel with various modifications to the frame of reference and dynamic organization of the information. In this research, this type of database search is realized through an information access space dynamically constructed of hyperlinks based on an arbitrary frame of reference. The authors propose a new concept and structure for the frames of reference and develop a mechanism for dynamically linking individual database records with multiple information access spaces, dynamically constructed on the basis of declarative definitions of these frames of reference. The authors also provide a three‐dimensional interface for editing frames of reference and for spatial navigation threaded by these links. These operations correspond to query processing by narrowing down the subject tables and joining multiple tables; the user can gradually narrow his focus and arrive at the target information by dynamically modifying his frame of reference and repeating spatial movements. In this paper, a three‐dimensional interface is developed and database searches using that interface are evaluated; it is shown that this technique makes it possible to quickly access target information. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(8): 13–23, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20523
The influence of alkali‐degreasing on the chemical composition of hot‐dip galvanized steel surfaces
Authors: Berger Robert , Bexell Ulf , Stavlid Nils , Grehk T. Mikael
Published: May 2006

The influence of dipping temperature and time on the surface chemistry of hot‐dipped galvanized steel sheets during the alkaline degreasing process is investigated. The surface chemistry was monitored with scanning Auger electron spectroscopy (AES), X‐ray photoelectron spectroscopy (XPS), and time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS). The results show high Al concentrations on the untreated surfaces, which are significantly reduced during alkaline degreasing. The same conclusions could be drawn for the carbon compounds that accumulate on the surface during storage. The measurements reveal a gradual reduction in surface Al as the alkali solution temperature and/or degreasing time are increased. When degreasing was conducted at 70 °C for 30 s the surface was practically free from Al, which was present only in small islands. Furthermore, the experiments showed that the thickness of the oxide film covering the surfaces before and after alkaline degreasing is approximately 20 Å. The main constituents of the film varied from ZnAl hydroxide/oxide to Zn hydroxide/oxide, before and after degreasing, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Summary of ISO/TC201 technical report: ISO/TR 18392: 2005—Surface chemical analysis—X‐ray photoelectron spectroscopy—Procedures for determining backgrounds
Authors: Kövér L.
Published: May 2006

ISO Technical Report 18392 provides the guidance for determining backgrounds in X‐ray photoelectron spectra. The methods of background determination described in this report are applicable for the quantitative evaluation of the spectra of photoelectrons and Auger electrons excited by X‐rays from solid surfaces and surface nanostructures. Copyright © 2006 John Wiley & Sons, Ltd.
A NEXAFS orientation study of γ‐aminopropyltriethoxysilane on zinc oxide surfaces
Authors: Thomsen L. , Watts B. , Dastoor P. C.
Published: May 2006

Bifunctional silanes, such as γ‐aminopropyltriethoxysilane (γ‐APS), are able to adsorb to a substrate via both functional groups creating a number of possible orientations for an adsorbed molecule within an organosilane film. The orientation of dip coated γ‐APS films on native zinc oxide surfaces as a function of solution pH has been studied using near edge X‐ray absorption fine structure (NEXAFS) spectroscopy. The NEXAFS results shed further light on the changes in the orientation that take place during the oscillatory adsorption of these molecules and reveal new insights into the molecular reorganisations that occur with changing solution pH. The results are discussed in terms of an electrokinetic model that has been developed. Copyright © 2006 John Wiley & Sons, Ltd.