bluuebunny/crossref_metadata_2025 huggingface dataset:
The Tauern tunnel first and second tubes from the contractor's viewpoint
Authors: Weidinger Franz , Lauffer Harald
Published: February 2009

The construction of the first tube of the Tauern tunnels in the years 1970 to 1975 was a milestone in the development of the NATM and of modern tunnelling. Completely new methods were introduced and used successfully to overcome the strongly squeezing rock, which was the only possibility of mastering the large rock deformations and completing tunnelling within the planned deadline.

The driving of the second tube of the Tauern tunnel between 2006 and 2008 has shown that the basics of the NATM are still valid. The considerably more favourable system behaviour does, however, show that the state of knowledge in design and construction has developed greatly. The major difference is the increase of productivity and this is made clear by comparing the production assets used.
Changes in tunnelling over 20 years through the example of the Roppen tunnel
Authors: Brugger Gerhard , Sachs Manfred
Published: February 2009

20 years lie between the construction of the two tubes of the Roppen tunnel, during which time the world has changed not only politically and in general thinking but has also produced dramatic technical progress. Above all with the development of communication and information technology, the environment for the tunnel builder and the proceedings on the construction site have changed, unfortunately not always for the better. The positive and negative developments are discussed in a critical manner and a return to more community and more dialogue on site are proposed.
Hydroshield drive H3‐4 in the lower Inn valley – construction experience
Authors: Göbl Arthur
Published: February 2009

In the lower Inn valley in the Tyrol, the existing railway line is being widened to four tracks as part of the TEN (Trans European Network) section Munich‐Verona. The Brenner Railway Company has appointed the joint venture Porr Tunnelbau – Max Bögl for the construction of the section H3‐4. At the time of writing the article, two thirds of the 5.8 km long tunnelled section had been bored, with daily advance rates of up to 32 m being achieved. A Hydroshield is being used to bore the main tunnel with a diameter of 13.03 m. The tunnel gradient lies completely under the groundwater table. For long stretches, the tunnel route runs through loose sandy or gravelly soil with high and very changeable permeability. At the borders of the contract section, silty clay soil dominates.

Eleven shafts are being constructed every 500 m along the tunnel route to act as emergency exits. The shafts are constructed with diaphragm walls and are connected to the main tunnel by pipe‐jacked headings of 4.8 m diameter. Because of the groundwater pressure of about 3 bar throughout the site, a sealing block has to be constructed in advance at the junction area.
Tradenberg tunnel – the contractor in the role of client
Authors: Edlmair Gerald , Pacher Wolfgang
Published: February 2009

As part of the project “PPP Ostregion Paket 1”, a tunnelling project is being constructed on the basis of a performance specification for the first time in Austria, with the entire geological risk being borne by the contractor. The two‐tube Tradenberg tunnel, each tube carrying one traffic direction, is in the S1‐West section of the 51 km long Y‐Trasse to be constructed by the consortium Bonaventura. The overall length of the tunnel is 2,457 m or 2,423.5 m, of which 1,403.6 m or 1,359 m are to be mined underground. The entire section is to open for traffic in early 2010. The contract model has the effect of transferring competence to the contractor. This opens a wide range of organisational possibilities for the construction consortium, but accompanied by an enormous increase in responsibility and commercial risk.
Hieflau power station extension – mechanical tunnelling with innovative solutions
Authors: Gappmaier Franz , Weber Wolfgang , Bitschnau Markus
Published: February 2009

The extension of the Hieflau power station is intended to increase the productive water quantity from 60 to 90 m3/s. The normal power production of the power station, which was commissioned in 1955, will be increased by the planned measures by about 108 GWh/a. In addition to the necessary adaptations and refurbishment of the intake and discharge structures, the headrace tunnel to be constructed represents the most important part of the extension.
Power station construction then and now through the example of the Glockner/Kaprun power station group and the PSW Limberg II in Kaprun
Authors: Hager Andreas , Wagner Erich
Published: February 2009

The power station facilities at Glockner/Kaprun were constructed in the years from 1946 to 1955. The system consists of a main and an upper stage with a total generation capacity of 353 MW. Since 2006, the association Austrian Hydro Power has been working to extend the existing power station group Glockner/Kaprun with the addition of the pumped storage works Limberg II. This will be a new cavern power station with two reversible pump turbines each of 240 MW installed underground. In the course of 50 years, the technical equipment and tunnelling techniques have developed decisively, enabling the number of employees to be reduced considerably. Construction work high in the mountains was then and is still now characterised by extraordinary difficulties because of the altitude. Regular progress of construction work presumes careful planning and well thought‐out logistics.
Testing for genetic association in the presence of population stratification in genome‐wide association studies
Authors: Wang Kai
Published: February 2009

Genome‐wide case‐control association study is gaining popularity, thanks to the rapid development of modern genotyping technology. In such studies, population stratification is a potential concern especially when the number of study subjects is large as it can lead to seriously inflated false‐positive rates. Current methods addressing this issue are still not completely immune to excess false positives. A simple method that corrects for population stratification is proposed. This method modifies a test statistic such as the Armitage trend test by using an additive constant that measures the variation of the effect size confounded by population stratification across genomic control (GC) markers. As a result, the original statistic is deflated by a multiplying factor that is specific to the marker being tested for association. This deflating multiplying factor is guaranteed to be larger than 1. These properties are in contrast to the conventional GC method where the original statistic is deflated by a common factor regardless of the marker being tested and the deflation factor may turn out to be less than 1. The new method is introduced first for regular case‐control design and then for other situations such as quantitative traits and the presence of covariates. Extensive simulation study indicates that this new method provides an appealing alternative for genetic association analysis in the presence of population stratification. Genet. Epidemiol. 33:637–645, 2009. © 2009 Wiley‐Liss, Inc.
Recurrent seizures induce a reversible impairment in a spatial hidden goal task
Authors: Lin Hai , Holmes Gregory L. , Kubie John L. , Muller Robert U.
Published: February 2009

A major question concerning the learning and memory deficits characteristic of epilepsy is the relative importance of the initial insult that leads to recurrent, unprovoked seizures versus the seizures themselves. A related issue is whether seizure‐induced cognitive decline is permanent or reversible when convulsions cease. To address these problems, adult rats were extensively trained in the “spatial accuracy task,” a dry‐land analog of the Morris water maze. This task allows the rat's estimate of the location of a hidden goal zone to be repeatedly measured within each behavioral session. One aim was to measure, in well‐trained animals, the time course of any cognitive impairment caused by a daily flurothyl‐induced generalized seizure over 11 days. A second aim was to look for possible recovery during 9 subsequent days with no seizures. We saw a cumulative degradation in spatial performance during the seizure days and reversal of the deficit after seizures were stopped such that performance returned to baseline. Interestingly, the rate of learning to an asymptote, the rate of performance decline during one‐per‐day seizures and the rate of relearning during the recovery period were all similar. Given that the hippocampus plays an important role in spatial memory and that it is the brain structure most vulnerable to abnormal excitation the implication is that the hippocampus remains essential for precise spatial navigation even after prolonged training in locating a fixed goal zone. Clinically, this finding questions the assumption that patients who experience seizures should return to a baseline cognitive level within hours. © 2009 Wiley‐Liss, Inc.
Rigid Alicyclic Molecules from Bicyclo[2.2.1]hept‐2‐enes (=8,9,10‐Trinorbornenes) and 1,4‐Dipyridin‐2‐ylphthalazines as Stereoselective Coupling Agents
Authors: Margetić Davor , Murata Yasujiro , Komatsu Koichi , Marinić Željko
Published: February 2009

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For the preparation of rigid polycyclic molecules from 8,9,10‐trinorbornenes (=bicyclo[2.2.1]hept‐2‐enes), 1,4‐dipyridin‐2‐ylphthalazines were used. Cycloaddition reactions with trinorbornenes gave coupled products in a stereoselective manner. In these reactions, the phthalazines delivered a new bicyclo[2.2.2] moiety at the junction of two trinorbornene units, which could bear appropriate functional groups (Schemes 4and5). The crystal structure of a key cycloadduct,i.e., of18was also determined (Fig. 2). Relative reactivities for a series of phthalazines (Fig. 3) were estimated by density‐functional‐theory (DFT) calculations at the B3LYP/6‐31G* level (Table). The calculations indicated an increase of reactivity when the aromaticity of the phthalazine moiety is decreased. Finally, experimentally observed stereoselectivities of the phthalazine reactions with trinorbornenes were readily predicted by DFT calculations (Fig. 4).
Ceramides and Cerebrosides from Ligusticum chuanxiongHort.
Authors: Yang Nian‐Yun , Ren Dong‐Chun , Duan Jin‐Ao , Xu Xiao‐Hua , Xie Ning , Tian Li‐Juan
Published: February 2009

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Two new ceramides, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxypentadec‐8‐en‐2‐yl]heptacosanamide (1) and (2R)‐2‐hydroxy‐N‐{(3S,4S,5S)‐4‐hydroxy‐5‐[(4E)‐undec‐4‐en‐1‐yl]tetrahydrofuran‐3‐yl}heptacosanamide (2), were isolated from the aerial parts of Ligusticum chuanxiong, along with one known ceramide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tetracosanamide (3), and two known cerebrosides, (2R)‐N‐[(2S,3R,4E,8E)‐1‐(β‐D‐glucopyranosyloxy)‐3‐hydroxydodeca‐4,8‐dien‐2‐yl]‐2‐hydroxydocosanamide (4) and (2R)‐N‐[(2S,3S,4R,8E)‐1‐(β‐D‐glucopyranosyloxy)‐3,4‐dihydroxyoctadec‐8‐en‐2‐yl]‐2‐hydroxyhexadecanamide (5). Their structures were elucidated by extensive spectroscopic analysis, including 1D‐ and 2D‐NMR, as well as HR‐ESI‐MS experiments.
Imaging Technique with Liquid Crystals of Halogen‐Containing 3,6‐Distyrylpyridazines (=3,6‐Bis(2‐phenylethenyl)pyridazines)
Authors: Lifka Thorsten , Seus Peter , Oehlhof Annette , Meier Herbert
Published: February 2009

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The 3,6‐bis{(1E)‐2‐[4‐(dodecyloxy)phenyl]ethenyl}pyridazine (1a) was regio‐ and stereoselectively brominated or chlorinated to the (Z,Z)‐compounds 3 and 6, respectively. The conjugated core of these systems represents a mesogen for smectic (and nematic) liquid crystals and, moreover, a chromophore with an absorption at the UV/VIS border. Irradiation and efficient intersystem crossing to the triplet state leads to isomerization reactions (Z,Z)→(E,Z) in solution as well as in the thermotropic LC phases. Since (E,Z)‐configurations are only tolerated to a very small extent by the mesophases, the photoinduced transition S→N→I of 6 can be used as an imaging technique.
Sesquiterpenes and Dimers Thereof from Chloranthus fortunei
Authors: Wang Xia‐Chang , Wang Li‐Li , Ouyang Xiao‐Wei , Ma Shi‐Ping , Liu Jing‐Han , Hu Li‐Hong
Published: February 2009

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Four new compounds, including one new sesquiterpene dimer, i.e., shizukaol P (1), one new dimeric sesquiterpene glycoside, i.e., 9‐O‐β‐glucopyranosylcycloshizukaol A (2), and two new sesquiterpenes, i.e., shizukanolides G and H (3 and 4, resp.), together with eight known compounds, were isolated from the aerial part of Chloranthus fortunei. The structures and relative configurations were elucidated on the basis of spectroscopic data and by comparison with those of the related compounds reported in the literature.
Two New Securinega Alkaloids from Securinega suffruticosa
Authors: Qin Song , Liang Jing‐Yu , Guo Yue‐Wei
Published: February 2009

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Two new Securinega alkaloids, 2‐episecurinol A (1) and 8‐(diethylamino)‐2‐episecurinol A (2), together with the five known related analogues 3–7, were isolated from Securinega suffruticosa (Pall.) Rehd. Their structures were determined by detailed analysis of 1D‐ and 2D‐NMR spectra and by comparison with the related model compounds.
Two New Sesquiterpenes from Salvia roborowskiiMaxim
Authors: Liu Yong , Li Chong , Shi Jian‐Gong , Shi Yan‐Ping
Published: February 2009

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Two new sesquiterpenes, (1β,3β,4α,5α,6α,8α)‐guai‐10(14)‐ene‐3,4,6,8‐tetrol 3,6,8‐triacetate (1) and (3β,4α,6α,8β,9β,10α)‐8‐(acetyloxy)‐3,4 : 9,10‐diepoxygermacr‐7(11)‐eno‐12,6‐lactone (2) were isolated from the EtOH extract of Salvia roborowskii Maxim. Their structures were established by spectroscopic methods, including one‐ and two‐dimensional NMR techniques, and the relative configurations of these compounds were determined on the basis of NOE experiments.
Sesquiterpenes and Lignans from Tephrosia vogelii
Authors: Wei Huan‐Huan , Xu Han‐Hong , Xie Hai‐Hui , Xu Liang‐Xiong , Wei Xiao‐Yi
Published: February 2009

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A new guaiane sesquiterpene, (1β,6α,10α)‐guai‐4(15)‐ene‐6,7,10‐triol (1), and a new lignan, (+)‐lariciresinol 9′‐stearate (2), were isolated from the aerial parts of a leguminosae plant, Tephrosia vogelii, together with three known compounds, teclenone B, (1β,7R*)‐opposit‐4(15)‐ene‐1,7‐diol, and pinoresinol. Their structures were elucidated on the basis of spectral data.
ent‐Abietanoids and ent‐Isopimaranoid Glycosides from Isodon nervosus
Authors: Li Li‐Mei , Li Guo‐You , Ding Li‐Sheng , Pu Jian‐Xin , Xiao Wei‐Lie , Han Quan‐Bin , Sun Han‐Dong
Published: February 2009

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Three new and one known ent‐abietanoids, i.e., ent‐abienervonins A–C (1–3, resp.) and hebeiabinin B (4), and two new ent‐isopimaranoid glycosides, i.e., ent‐isopimanervosides A and B (5 and 6, resp.), along with seven known phenolic glycosides were isolated from the aerial parts of Isodon nervosus. The structures of the new compounds were elucidated on the basis of spectroscopic and chemical evidence.
Three New Diterpenoids from Salvia przewalskiiMaxim
Authors: Xu Gang , Peng Li‐Yan , Tu Lin , Li Xiao‐Li , Zhao Yu , Zhang Peng‐Tao , Zhao Qin‐Shi
Published: February 2009

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Three new compounds including one ortho‐quinone‐type icetexane diterpenoid, i.e., przewalskin E (1), one abietane dinorditerpenoid, i.e., przewalskin F (2), and one 7,20‐epoxyabietane diterpenoid, i.e., przewalskin G (3), were isolated from Salvia przewalskii Maxim. The identification and structure elucidation of these compounds were based on 1D‐ and 2D‐NMR spectral‐data analysis. It is noteworthy that przewalskin E (1), featured with an 11,12‐dioxoicetexane skeleton, represents the second example of a naturally occurring ortho‐quinone‐type icetexane diterpenoid from Salvia plants.
A New Tricyclo[6.3.1.02,5]dodecane Sesquiterpene from Cultures of the Basidiomycete Campanella junghuhnii
Authors: Liu Rong , Zhou Zhong‐Yu , Xu Di , Wang Fei , Liu Ji‐Kai
Published: February 2009

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A new sesquiterpene with a tricyclo[6.3.1.02,5]dodecane skeleton, 2,3,6‐trihydroxycaryol‐5‐en‐7‐one (1), was isolated from the culture of the basidiomycete Campanella junghuhnii. The structure of 1 was elucidated on the basis of extensive spectroscopic analysis including IR, UV, MS, 1D‐ and 2D‐NMR experiments.
Identification of Major Alkaloids in Rat Urine by HPLC/DAD/ESI‐MS/MS Method Following Oral Administration of Cortex Phellodendri Decoction
Authors: Ma Chun‐Hui , Li Zhi‐Xiong , Wang Long‐Xing , Tang Yi‐Hong , Xiao Hong‐Bin , Huang Cheng‐Gang
Published: February 2009

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A rapid, sensitive, and specific high‐performance liquid chromatography (HPLC), diode‐array detection, and mass‐spectrometry techniques were developed for an identification of the constituents of Cortex Phellodendri and their metabolites in rat urine. The dose of 10 ml/kg of Cortex Phellodendri decoction was used for rats' oral administration. 0–24‐h Urine was purified using a C18 solid‐phase extraction cartridge, and then analyzed by an on‐line MS detector. A total of 13 characteristic HPLC peaks were detected in the urine samples. Nine of them, including five alkaloids and four of their metabolites, were tentatively elucidated as magnoflorine (1), the glucuronide conjugate of demethyleneberberine (2), menisperine (3), jatrorrhizine 3‐O‐glucuronide (4), berberubine 9‐O‐glucuronide (5), jatrorrhizine (6), the monomethyl and monohydroxy catabolite of berberubine (7), palmatine (8), and berberine (9). Identification and structural elucidation of the metabolites were performed by comparing their MSn spectra data with those reported.
Optimized Batchwise and Continuous Microreactor Synthesis of a (Bathophenanthroline)ruthenium(II) Complex Carrying Different Ligands
Authors: Kramer Rolf A. , Rumi Luigi , Bannwarth Willi
Published: February 2009

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By changing the Ru‐source, the reaction conditions, and the workup/purification procedure, the batchwise synthesis of a mixed [RuII(bathophenanthroline)] complex, i.e., of 4b, could substantially be improved (bathophenanthroline=4,7‐diphenyl‐1,10‐phenanthroline). In addition, we were able to adapt both steps of the synthesis to a microreactor system leading to the desired Ru‐complex in a continuous preparation in very high yields. The latter approach is especially suited for an envisaged scale‐up.
Development of a new method of wavelet aided trend detection and estimation
Authors: Adamowski Kaz , Prokoph Andreas , Adamowski Jan
Published: February 2009

The detection and estimation of trends in the presence of noise, periodicities, or discontinuous patterns is important in hydrology and climate research studies. The basic idea of currently available trend estimation techniques (tests) is that the trends should be smooth and monotonic; however, hydro‐climatologic variables contain multiple signals, and have segments of increasing and decreasing trends. As a result, estimating trends in time series is an essential but arcane art and it is therefore important to continue developing the theory and practice of trend analysis.

In this paper, a new technique is proposed based on the continuous wavelet transform (CWT). CWT permits the transformation of observed time series into wavelet coefficients according to time and scale simultaneously. These coefficients can be used to detect and estimate trends or to reconstruct signals that are of interest. The proposed CWT method was first tested on computer‐generated data exhibiting both periodic and noise components. It was then applied to observed monthly minimum streamflow observations extracted from the Reference Hydrometric Basin Network (RHBN) for five different eco‐zones in Canada.

It was concluded that the proposed wavelet transform (WT) based method provides a very flexible and accurate tool for detecting and estimating complicated signals. The results from monthly minimum observations indicate that short period fluctuations are decreasing, while multi‐annual variability is increasing in Canada. And finally, a persistent ∼55‐year signal is well correlated with the Pacific Decadal Oscillation in all records, which indicates that trends are not controlled by a single factor. Copyright © 2009 John Wiley & Sons, Ltd.
Scaling properties and spatial organization of snow depth fields in sub‐alpine forest and alpine tundra
Authors: Trujillo Ernesto , Ramírez Jorge A. , Elder Kelly J.
Published: February 2009

This paper reports on a study analysing the spatial distribution functions, the correlation structures, and the power spectral densities of high‐resolution LIDAR snow depths (∼1 m) in two adjacent 500 m × 500 m areas in the Colorado Rocky Mountains, one a sub‐alpine forest the other an alpine tundra. It is shown how and why differences in the controlling physical processes induced by variations in vegetation cover and wind patterns lead to the observed differences in spatial organization between the snow depth fields of these environments. In the sub‐alpine forest area, the mean of snow depth increases with elevation, while its standard deviation remains uniform. In the tundra subarea, the mean of snow depth decreases with elevation, while its standard deviation varies over a wide range. The two‐dimensional correlations of snow depth in the forested area indicate little spatial memory and isotropic conditions, while in the tundra they indicate a marked directional bias that is consistent with the predominant wind directions and the location of topographic ridges and depressions. The power spectral densities exhibit a power law behaviour in two frequency intervals separated by a break located at a scale of around 12 m in the forested subarea, and 65 m in the tundra subarea. The spectral exponents obtained indicate that the snow depth fields are highly variable over scales larger than the scale break, while highly correlated below. Based on the observations and on synthetic snow depth fields generated with one‐ and two‐dimensional spectral techniques, it is shown that the scale at which the break occurs increases with the separation distance between snow depth maxima. In addition, the breaks in the forested area coincide with those of the corresponding vegetation height field, while in the tundra subarea they are displaced towards larger scales than those observed in the corresponding vegetation height field. Copyright © 2009 John Wiley & Sons, Ltd.
Carbon and nitrogen cycling in a vegetated lowland chalk river impacted by sediment
Authors: Trimmer M. , Sanders I. A. , Heppell C. M.
Published: February 2009

We investigated the accumulation and biogeochemical cycling of organic matter beneath Ranunculus plants in a lowland river. Organic carbon accumulated beneath the plants at a mean rate of 20 mmol C m−2 h−1. Annual gross primary production for both Ranunculus and its biofilm, and the microphytobenthos, could account for 26% of the carbon accumulated. The remainder was attributable to organic carbon in both suspended particulate matter (77%) and that associated with sands saltating along the bottom (33%). Maximum carbon oxidation occurred in spring and early summer and declined thereafter. The efflux of CO2 was greater than the carbon equivalents due to reduction of O2, NO3− and SO42− measured at the surface, which suggested a significant contribution to carbon oxidation from the subsurface and some oxidation via alternative electron acceptors. The peak in carbon oxidation could not be accounted for by either rising temperature or primary production but tracked the quality of recently deposited allochthonous organic matter. The ratio of carbon oxidation to total organic carbon accumulation suggested that 19% of the organic matter deposited was remineralised on an annual basis, although this reached 58% in June. We calculate that a total of 3·6 mol N m−2 y−1 was mineralised in the sediment, of which 11% could be accounted for by the measured efflux of NH4+. The remainder could be accounted for by the N demand from primary production (67% macrophytes/biofilm; 36% phytobenthos). Copyright © 2009 John Wiley & Sons, Ltd.
Quantifying the impact of groundwater discharge on the surface–subsurface exchange
Authors: Boano Fulvio , Revelli Roberto , Ridolfi Luca
Published: February 2009

The exchange of oxygen and nutrients between the well‐aerated stream water and the subsurface water is crucial for the biochemical conditions of the hyporheic zone. The metabolic activity of the hyporheic microorganisms controls the fate of nitrogen and phosphorus in the pore water, and influences the fate of these nutrients at the catchment scale. Unfortunately, the incomplete knowledge of the complex hydrodynamics of the coupled surface‐subsurface flow field often hinders the understanding of the ecological relevance of the hyporheic processes. Here, we analyse the influence of groundwater discharge through the streambed on bedform‐induced hyporheic exchange. A simple mathematical model of a coupled stream‐aquifer system is developed in order to describe the essential feature of the surface‐subsurface exchange. The most representative characteristics of the hyporheic exchange, e.g. the depth of the hyporheic zone ‐ are parametrized in terms of a small number of easily measurable quantities. This information on the hyporheic flow field provides the fundamental basis for the study of the ecological function of the hyporheic zone. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a cell‐derived matrix: Effects of epidermal growth factor in chemically defined culture
Authors: Throm Angela M. , Liu Wai‐Ching , Lock Chi‐Hung , Billiar Kristen L.
Published: February 2009

Extracellular matrices without animal components and with high mechanical strength are needed for the development of the next generation of viable skin replacements. The goal of this study was to determine the optimal concentration of epidermal growth factor (EGF) to maximize the strength and collagen content of cell‐derived matrix (CDM) produced by fibroblasts in vitro in serum‐free media. Scaffold‐free CDM samples were produced by human dermal fibroblasts in the presence of 0–50 ng/mL EGF in chemically defined media. After 21 days of culture, a membrane inflation system was used to measure the biaxial tensile strength, failure stretch ratio, and thickness of each treatment group. The fibroblasts treated with 5 ng/mL EGF produced the thickest matrix (270 μm). A thinner (130 μm) matrix, produced when the fibroblasts were treated with 0.5 ng/mL, had an ultimate tensile strength (895 kPa), greater than two times that of the other treatment groups. The fibroblasts treated with 0.5 ng/mL also had the highest collagen density (23.5 mg/cm3). Fibroblasts stimulated with the lowest (0.05 ng/mL) and highest (50 ng/mL) concentrations of EGF produced significantly weaker matrices and lower collagen densities. There was no significant correlation between UTS and collagen density suggesting that mechanisms other than density contribute to the strength of the matrix. Taken together, these data indicate that the optimal EGF concentration depends upon the relative importance of matrix strength and volume in a given application and that 0.5–5.0 ng/mL EGF promotes production of a robust extracellular matrix in only 3 weeks. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Composite fibrous membranes of PLGA and chitosan prepared by coelectrospinning and coaxial electrospinning
Authors: Wu Lili , Li Hua , Li Shuo , Li Xiaoran , Yuan Xiaoyan , Li Xiulan , Zhang Yang
Published: February 2009

Membranes made of hybrid poly(lactide‐co‐glycolide)/chitosan fibers (H‐PLGA/chitosan) and core/shell structured PLGA/chitosan fibers (C‐PLGA/chitosan) were produced by coelectrospinning and coaxial electrospinning, respectively. The morphology, mechanical properties, water uptakes of the electrospun fibrous membranes were characterized, and the cytocompatibility of human embryo skin fibroblasts (hESFs) was investigated in comparison with each other as well as with the electrospun PLGA and chitosan membranes. Results of transmission electron microscope and X‐ray photoelectron spectroscopy confirmed the core/shell structure of the C‐PLGA/chitosan fiber. Because of the introduction of chitosan, both H‐PLGA/chitosan and C‐PLGA/chitosan membranes showed significantly higher water uptakes than that of PLGA but there was no significant difference between those of C‐PLGA/chitosan and chitosan membranes. In dry state, the C‐PLGA/chitosan membranes exhibited extremely higher Young's moduli (178.7 ± 50.4 MPa) and strength (2.73 ± 0.30 MPa) than those of H‐PLGA/chitosan membranes (40.48 ± 4.07, 1.44 ± 0.12 MPa), respectively, but the values in wet state went down sharply because of the large amount (about 91%) of chitosan as the shell. Both H‐PLGA/chitosan and C‐PLGA/chitosan membranes showed better cytocompatibility than the PLGA membrane in adhesion, viability assays as well as morphology observation. The obtained composite H‐ or C‐PLGA/chitosan membranes would be potentially applied in wound dressings or skin tissue engineering. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Changes in protein expression associated with chronic in vitro exposure of hexavalent chromium to osteoblasts and monocytes: A proteomic approach
Authors: Raghunathan Vijay Krishna , Grant M. Helen , Ellis Elizabeth M.
Published: February 2009

Cr (VI) is a well‐recognized environmental toxin and carcinogen. It is known to be released from orthopedic metal implants in‐situ by biocorrosion and is speculated to play a role in periprosthetic osteolysis. It is hence essential to understand its long‐term biological effects. We have assessed the in vitro responses of osteoblasts and monocytes to chronic exposure (3 weeks) to Cr (VI), at concentrations that have been measured in patients with metal implants, using two‐dimensional gel electrophoresis. Cr (VI) exposure resulted in a differential time‐dependent regulation of glycolytic, stress, and cytoskeletal proteins. The proteins that have been found to be altered in expression play an essential role in normal cellular functioning such as energy metabolism, cell signaling, and proliferation. The results highlight the complex molecular changes that occur in both cell types with long‐term exposure to Cr and may be useful in establishing a series of clinically useful biomarkers to monitor long‐term use of metallic implants. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Evaluation of a silica‐containing bone graft substitute in a vertebral defect model
Authors: Kobayashi Hideo , Turner A. Simon , Seim Howard B. , Kawamoto Teruya , Bauer Thomas W.
Published: February 2009

Orthopedic and spine surgeons are in need of supplements or replacements for autograft. We investigated the histological properties of three formulations of Calcium Sodium Phosphosilicate [calcium sodium phosphosilicate putty with or without autograft and NovaBone 45S5 Bioglass particulate (NovaBone, LLC, Jacksonville, FL)] using a sheep vertebral bone void model. Bone voids were surgically created in L3, L4, and L5 in each of 22 sheep, and the voids were filled with one of the tested biomaterials or left empty as a control. Histological evaluations were performed at either: 0, 6, or 12 weeks after surgery. Undecalcified sections were digitized, and the areas of the original defect and new bone were quantified. Decalcified sections were evaluated qualitatively. Histomorphometry showed a significant increase in the amount of bone between 6 and 12 weeks in all groups, but there was no significant difference in new bone formation among the formulations or between any formulation and the empty defects. The granules of all three formulations were associated with an inflammatory reaction. Many of the particles appear to have a hollow center, and the narrow tunnel through the center of the particles was sometimes associated with acute inflammation especially at 6 weeks. These particles were also associated with chronic inflammation at both 6 and 12 weeks, although the extent of inflammation decreased between 6 and 12 weeks. The search for the optimum bone graft substitute/extender will continue. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Surface characteristics and protein adsorption on combinatorial binary Ti‐M (Cr, Al, Ni) and Al‐M (Ta, Zr) library films
Authors: Bai Zhijun , Filiaggi M. J. , Sanderson R. J. , Lohstreter L. B. , McArthur M. A. , Dahn J. R.
Published: February 2009

Systematic studies of protein adsorption onto metallic biomaterial surfaces are generally lacking. Here, combinatorial binary library films with compositional gradients of Ti1‐xCrx, Ti1‐xAlx, Ti1‐xNix and Al1‐xTax, (0 <x < 1) and Al1‐yZry (0 < y <0.5) as well as corresponding pure metal films were sputtered onto clean Si surfaces. Bulk and surface chemistry, film microstructure, and surface roughness were subsequently correlated to fibrinogen or albumin adsorption measured using a high throughput wavelength dispersive spectroscopy technique. X‐ray diffraction revealed these binary films to have crystalline phases present primarily at either extreme of the compositional library and an amorphous zone dominating along the gradient. These mirror‐like films were generally found by atomic force microscopy to have a roughness of less than 8 nm, with any relative increases in roughness consistent with the development of crystalline phases. Surface chemistry by quantitative high‐resolution X‐ray photoelectron spectroscopy differed significantly from bulk film composition as measured by electron microprobe, with TiO2 and Al2O3 preferentially forming on the binary film surfaces. Correspondingly, protein adsorption onto these films closely correlated with their surface oxide fractions. Aluminum deposited as either a constant‐composition film or as part of a binary library consistently adsorbed the least amount of albumin and fibrinogen, with alumina‐enrichment of the surface oxide correlating with this adsorption. Overall, this combinatorial materials approach coupled with high‐throughput surface analytical methods provides an efficient method of screening potential metallic biomaterials that may enable as well systematic studies of surface properties driving protein adsorption on these metal / metal oxide systems. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Evaluation of polydimethylsiloxane modification methods for cell response
Authors: Pakstis L. M. , Dunkers J. P. , Zheng A. , Vorburger T. V. , Quinn T. P. , Cicerone M. T.
Published: February 2009

Many methods exist in the literature to modify surfaces with extracellular matrix (ECM) proteins prior to cell seeding. However, there are few studies that systematically characterize and compare surface properties and cell response results among modification methods that use different bonding mechanisms. In this work, we compare cell response and physical characterization results from fibronectin or laminin attached to polydimethylsiloxane (PDMS) elastomer surfaces by physical adsorption, chemisorption, and covalent attachment to determine the best method to modify a deformable surface. We evaluate modification methods based on completeness and uniformity of coverage, surface roughness, and hydrophilicity of attached ECM protein. Smooth muscle cell adhesion, proliferation, morphology, and phenotype were also evaluated. We found that chemisorption methods resulted in higher amounts of protein attachment than physical adsorption and covalent bonding of the ECM proteins. Cell response to protein‐modified surfaces was similar with respect to cell adhesion, area, aspect ratio, and phenotype. When all the data are considered, the chemisorption methods, most notably silane_70, provide the best surface properties and highest cell proliferation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Chondrogenesis using mesenchymal stem cells and PCL scaffolds
Authors: Kim Hye‐Joung , Lee Jin‐Ho , Im Gun‐Il
Published: February 2009

We tested the in vitro feasibility of porous PCL (poly(ε‐caprolactone)) as a scaffold for cartilage tissue engineering from mesenchymal stem cells (MSCs) and determined the effects of various surface treatments. Three porous PCL scaffold modifications were examined: (1) PCL/Pluronic F127, (2) PCL/collagen, and (3) PCL/Pluronic F127/collagen, in addition to (4) PCL‐only. MSCs (5 × 105) were seeded in PCL scaffolds of pore size 100–150 μm, and after 3 weeks of in vitro culture, MSC‐scaffolds were investigated for gross appearance, DNA amount, glycosaminoglycan (GAG) content, chondrogenic gene expression, and histology. Grossly, the cell‐scaffold complexes became harder, and were more easily manipulated with a forceps after 3 weeks of culture. The three surface‐treated scaffolds had higher DNA contents than did the PCL‐only scaffold, and the GAG contents in PCL/collagen and PCL/F127/collagen scaffolds were higher than those seen in the PCL‐only scaffold. Real‐time PCR showed that Sox‐9 and COL2A1 mRNA levels were remarkably elevated in PCL/collagen and PCL/F127/collagen scaffolds versus the PCL‐only scaffold. On the other hand, Col1A1 and Col10A1 mRNA levels were lower in the three modified PCL scaffolds than in the PCL‐only scaffold. Histological findings generally concurred with GAG and RT‐PCR findings, and demonstrated the affinity of PCL‐based scaffolds for MSCs and the potentials of these scaffold to induce chondrogenic differentiation. Cells showed more differentiated appearance and more abundant extracellular matrix formation in PCL/collagen and PCL/collagen/F127 scaffolds. Our findings suggest that PCL‐based porous scaffolds may be useful carriers for MSC transplantation in the cartilage tissue engineering field, and that collagen‐based surface modifications further enhance the chondrogenic differentiation of MSCs. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Preparation and properties of nanometer titanium dioxide/silk fibroin blend membrane
Authors: Xia Youyi , Gao Guoan , Li Yuewu
Published: February 2009

A novel nanometer titanium dioxide (nanoTD)/silk fibroin (SF) blend membrane was prepared and characterized by AFM, FTIR, DSC, and XRD. The strength, solubility and thermal properties and the antibacterial activity of the blend membrane were then investigated. The results show that at a nanoTD/SF weight ratio of 0.1%, nanoTD particles were evenly dispersed in the blend membrane. The blend membrane exhibited a crystalline 2θ XRD peak at 21.1° and the decomposition temperature was 28.72°C higher than for a pure SF membrane. The results show that the blend membrane had higher crystallinity and better antibacterial activity and strength than a pure SF membrane, whereas its solubility was lower. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The great “say on pay” debate
Authors: Bean LuAnn
Published: February 2009

With the recent political changes, some analysts predict a stronger “say on pay” movement in the corporate world—with shareholders demanding the right for a nonbinding vote on the CEO's compensation. But what's really likely to happen? And what should you do right now? © 2009 Wiley Periodicals, Inc.
Moving targets: The dynamics of goal setting and performance
Authors: McNair‐Connolly C. J. , Watts Ted , Polutnik Lidija
Published: February 2009

As organizations seek ways to improve performance, reduce costs, and maximize the value created for customers and other stakeholders, they need to make sure that the dynamics embedded in their management control system—the linkages between goal setting and performance—create a natural platform for internalization of the organization's goals by the workforce. © 2009 Wiley Periodicals, Inc.
How strategic budgeting can control cost while improving performance
Authors: Taylor Audrey
Published: February 2009

When managers focus on overall goals in making resource choices, wiser choices are made, efficiencies encouraged, and collaboration fostered. It is simple, fast, and flexible. To that end, this article presents a format for budgeting called strategic budgeting. This new budgeting format addresses the frustrations of implementing—and being held accountable for—a budget. It uses the concepts of information symmetry, mutual monitoring, and a group budget buffer (a pool that supports the funding of nonbudgeted expenditures). Strategic budgeting thus ensures that funding follows strategic intent—in other words, what actually supports a company's goals. © 2009 Wiley Periodicals, Inc.
Racing to success by identifying key performance drivers
Authors: Paulson Gjerde Kathy A. , Hughes Susan B.
Published: February 2009

This article focuses on ways to identify key performance drivers (KPDs) and key performance indicators (KPIs). Unfortunately, lists of KPIs published in the past often focus on one industry and assume a generic business strategy. In addition, an overemphasis on financial measures will mean that KPIs will reflect past activities rather than signaling future performance. Managers need to develop meaningful metrics for their own businesses, not use generic KPIs. This is particularly important in small and medium‐sized enterprises. How adept are you at this task? Do you know what drives net income for your organization? © 2009 Wiley Periodicals, Inc.
Cloning and analysis of rat osteoclast inhibitory lectin gene promoter
Authors: Quan Jin‐Xing , Zheng Fang , Li Xiao‐Xia , Hu Li‐Ling , Sun Zi‐Yang , Jiao Yan‐Li , Wang Bao‐Li
Published: February 2009

Osteoclast inhibitory lectin (OCIL) is a novel regulator of bone remodeling, however, little is known concerning how OCIL is regulated to date. In this study, approximately 4.4 kb of the 5′‐flanking sequence of rat OCIL gene was cloned into the promoter‐less reporter vector pGL3‐basic and transiently transfected into three different cell lines. The differences in the levels of luciferase activity paralleled well with the levels of OCIL mRNA expression in these cells, suggesting that the regulation of rat OCIL gene expression occurs mainly at the transcriptional level. Additional luciferase assays using a series of constructs containing unidirectionally deleted fragments showed that the construct‐1819/pGL3 (−1819 to +118) exhibited the highest luciferase activity, suggesting the presence of functional promoter in this region. The region from −4370 to −2805 might contain negative regulatory elements, while the region from −1819 to −1336 might have important positive regulatory elements that enhance OCIL transcription. Sequence analysis of the promoter revealed the absence of both TATA and CAAT boxes. However, in the proximal promoter region (−81 to +118), several potential transcription factor binding sites that may be responsible for the basal transcriptional activity of rat OCIL promoter were observed. The promoter contains several potential Sp1 binding sites, and cotransfection of a shRNA expression plasmid that knockdowns Sp1 significantly reduced OCIL promoter activity and endogenous gene expression and moreover, overexpressing Sp7, a Sp1 family member that also binds to Sp1 binding sequence, increased OCIL promoter activity and gene expression, suggesting a role of Sp1 family proteins in regulation of OCIL transcription. J. Cell. Biochem. 106: 599–607, 2009. © 2009 Wiley‐Liss, Inc.
Almost resolvable cycle systems—an analogue of Hanani triple systems
Authors: Lindner C. C. , Meszka M. , Rosa A.
Published: February 2009

The purpose of this paper is the initiation of an attack on the general existence problem for almost resolvable 2k‐cycle systems. We give a complete solution for 2k=6 as well as a complete solution modulo one possible exception for 2k=10 and 14. We also show that the existence question for almost resolvable 2k‐cycle systems can be settled if we can show the existence for the two smallest possible orders 4k+1 and 8k+1. © 2009 Wiley Periodicals, Inc. J Combin Designs 17: 404–410, 2009
K6‐minors in triangulations and complete quadrangulations
Authors: Mukae Raiji , Nakamoto Atsuhiro
Published: February 2009

In this paper, we shall prove that a projective‐planar (resp., toroidal) triangulation G has K6 as a minor if and only if G has no quadrangulation isomorphic to K4 (resp., K5 ) as a subgraph. As an application of the theorems, we can prove that Hadwiger's conjecture is true for projective‐planar and toroidal triangulations. © 2009 Wiley Periodicals, Inc. J Graph Theory 60: 302‐312, 2009
Implications among linkage properties in graphs
Authors: Liu Qi , West Douglas B. , Yu Gexin
Published: February 2009

Given a graph H with vertices w1, …, wm, a graph G with at least m vertices is H‐linked if for every choice of vertices v1, …, vm in G, there is a subdivision of H in G such that vi is the branch vertex representing wi (for all i ). This concept generalizes the notions of k‐linked, k‐connected, and k‐ordered graphs. For graphs H1 and H2 with the same order that are not contained in stars, the property of being H1‐linked implies that of being H2‐linked if and only if H2⊆H1. The implication also holds when H1 is obtained from H2 by replacing an edge xy with an edge from y to a new vertex x′. Other instances of nonimplication are obtained, using a lemma that the number of vertices appearing in minimum vertex covers of a graph G is at most the vertex cover number plus the size of a maximum matching. © 2009 Wiley Periodicals, Inc. J Graph Theory 60: 327‐337, 2009
Oligohis‐tags: mechanisms of binding to Ni2+‐NTA surfaces
Authors: Knecht Steven , Ricklin Daniel , Eberle Alex N. , Ernst Beat
Published: February 2009

Since immobilized metal ion affinity chromatography (IMAC) was first reported, several modifications have been developed. Among them, Ni2+ immobilized by chelation with nitrilotriacetic acid (NTA) bound to a solid support has become the most common method for the purification of proteins carrying either a C‐ or N‐terminal histidine (His) tag. Despite its broad application in protein purification, only little is known about the binding properties of the His‐tag, and therefore almost no thermodynamic and kinetic data are available. In this study, we investigated the binding mechanism of His‐tags to Ni2+‐NTA. Different series of oligohistidines and mixed oligohistidines/oligoalanines were synthesized using automated solid‐phase peptide synthesis (SPPS). Binding to Ni2+‐NTA was analyzed both qualitatively and quantitatively with surface plasmon resonance (SPR) using commercially available NTA sensor chips from Biacore. The hexahistidine tag shows an apparent equilibrium dissociation constant (KD) of 14 ± 1 nM and thus the highest affinity of the peptides synthesized in this study. Furthermore, we could demonstrate that two His separated by either one or four residues are the preferred binding motifs within hexahis tag. Finally, elongation of these referred motifs decreased affinity, probably due to increased entropy costs upon binding. Copyright © 2009 John Wiley & Sons, Ltd.