bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of atmospheric stability above an evergreen forest in central Cambodia
Authors: Tamai Koji , Nobuhiro Tatsuhiko , Shimizu Akira , Kabeya Naoki , Chann Sophal , Nang Keth
Published: February 2008

Micrometeorological observations from a tower in a forest in central Cambodia were used to estimate forest water yields. For these estimates, the turbulent boundary layer was identified from tower observations of wind profiles. Indices including the stability length, friction velocity, and Richardson numbers were calculated to diagnose boundary layer characteristics. The calculated stability length indicated that the atmospheric condition was between weakly unstable and weakly stable 63% of the time. The calculated friction velocity exceeded 0·5 m s−1 77% of the time, and the calculated Richardson number was smaller than the critical number (0·2) 72% of the time. The indices calculated in this study indicate that the degree of atmospheric stability over this evergreen forest in central Cambodia is generally suitable for tower flux observations. Copyright © 2008 John Wiley & Sons, Ltd.
Investigation of runoff generation in a pristine, poorly gauged catchment in the Chilean Andes II: Qualitative and quantitative use of tracers at three spatial scales
Authors: Blume Theresa , Zehe Erwin , Bronstert Axel
Published: February 2008

Understanding runoff generation processes is important for flood prediction, water management, erosion control, water quality, contaminant transport and the evaluation of impacts of land use change. However, little process research has been carried out in southern Chile. In particular the young volcanic ash soils, which are typical for this area, are not well understood in their hydrologic behaviour. To establish a ‘reference study’ which can then be used for comparison with other (disturbed) sites, this study focuses on the investigation of runoff generation processes in an undisturbed, forested catchment in the Chilean Andes. The paper reports on an investigation of these processes with different tracer methods at different spatial scales. Hydrograph separation with environmental isotopes and geochemical constituents was used on the catchment scale. Thermal energy was used as a tracer to investigate groundwater–surface water interactions at the local stream reach scale and dye tracers were used to study infiltration and percolation characteristics at the plot scale. It was found that pre‐event water dominates the storm hydrograph. In the lower reaches, however, water usually exfiltrates from the stream into the adjacent aquifer. The dye tracer experiments showed that while preferential vertical flow dominates under forest, water infiltrates as a straight horizontal front in the bare volcanic ashes (no vegetation) on the catchment rim. Subsurface flow patterns in the forest differ significantly from summer to winter. All three approaches used in this study suggest an important shift in dominant processes from dry to wet season. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of passivation treatments on titanium alloy with nanometric scale roughness and induced changes in fibroblast initial adhesion evaluated by a cytodetacher
Authors: Wang C.‐C. , Hsu Y.C. , Su F.C. , Lu S.C. , Lee T.M.
Published: February 2008

Passivation treatments of titanium alloy alter not only its nanosurface characteristics of oxides and ion release but also surface roughness (Ra), and wettability as well, where nanosurface characteristics of oxides include chemistries of oxides, amphoteric‐OH groups adsorbed on oxides, and oxide thickness. Consequently, the passivation treatment affects the alloy's cyto‐comparability. In this study, we polish specimens to achieve nanometric scale roughness. In addition, treatment effects are evaluated for surface topology, roughness, wettability, and responses of fibroblasts consisting of MTT assay, initial adhesion strength, and morphology. The initial adhesion strength is measured using a cyto‐detacher that achieves nano‐Newton resolution. Results reveal that (1) the treatment effects on the percentage of TiOH basic groups and wettability are nearly collinear; (2) the Ra of passivated Ti‐6Al‐4V ranges from 1.9 to 7.4 nm; (3) the initial adhesion strength of fibroblast ranges from 58 to 143 nN, and it is negatively correlated to the Ra; (4) the passivation results in distinguishable morphologies, which further substantiate the negative correlation between cell initial adhesion force and Ra; and (5) our results fall short of confirming previous reports that found positively charged functional groups promoting fibroblast attachment and spread. Potential causes of the inconsistency are addressed. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Microarray‐based gene expression analysis of human osteoblasts in response to different biomaterials
Authors: Bombonato‐Prado Karina F. , Bellesini Larissa S. , Junta Cristina M. , Marques Márcia M. , Passos Geraldo A. , Rosa Adalberto L.
Published: February 2008

Several biomaterials have been widely used in bone regeneration/substitution procedures in orthopedic and oral surgery. However, how these biomaterials alter osteoblast gene expression is poorly understood. We therefore attempted to address this question by using cDNA microarray technique to identify genes that are differentially regulated in osteoblasts exposed to biomaterials comprehending the biocompatibility spectrum of bioactive (bioglass and hydroxyapatite), bioinert (Ti and stainless steel), and biotolerant (polymethylmethacrylate). By using a cDNA microarray containing 687 human IMAGE sequences, we identified in primary cultures of osteoblastic cells differentiated from the human bone marrow and exposed to these biomaterials, genes whose expression was significantly upregulated or downregulated. Among the differentially expressed genes we have found those involved with cell cycle regulation, cell differentiation and proliferation, apoptosis, cell adhesion, bone mineralization and skeletal development. These results can be relevant to a better understanding of the molecular mechanism underlying the behavior of osteoblasts in bone regenerative procedures. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Poly(ethylene terephthalate)/hydroxyapatite biomaterials: Preparation, characterization, and in vitro bioactivity
Authors: Siriphannon Punnama , Monvisade Pathavuth
Published: February 2008

Poly(ethylene terephthalate)/hydroxyapatite (PET/HAp) composites were prepared by mixing HAp powder with a mixture solution of cyclic oligo(ethylene terephthalate) (C‐OET) and dibutyl tinoxide catalyst in dichrolomethane, and then shaping the precomposites in cylindrical pellets. The C‐OET in the precomposites was ring‐opening polymerized (ROP) to PET under vacuum at 250°C for 24 h. The PET/HAp composites were formulated with HAp to PET ratios of 60:40 (H6P4) and 50:50 (H5P5). The ROP‐PET in the composites was present as a thin‐layer coating on the HAp grains and evenly distributed throughout the samples. Compressive strength of the PET/HAp composites was significantly increased from 8 MPa of the H10P0 to 17 and 29 MPa for H6P4 and H5P5, respectively. In vitro bioactivity of the PET/HAp composites was studied by soaking in simulated body fluid (SBF) at 36.5°C for 7–28 days. After prolonged soaking, the HAp nanocrystals precipitated from the SBF solution and formed as a layer of globular aggregates, coated on the composite surfaces. The H6P4 composite showed faster formation rate of nano‐HAp than the H5P5 composite, indicating that the bioactivity of PET/HAp composites depended on the amount of HAp. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Decreased macrophage density on carbon nanotube patterns on polycarbonate urethane
Authors: Kim Jong Youl , Khang Dongwoo , Lee Jong Eun , Webster Thomas J.
Published: February 2008

Nanotechnology is creating materials that can regenerate numerous tissues (including those used for bone, vascular, cartilage, bladder, and neuronal systems) better than what is currently being implanted. Despite this promise, little is known about the functions of wound healing cells (such as macrophages) on nanomaterials. Carbon nanotubes are intriguing nanomaterials for implantation due to their unique biologically inspired surface, electrical, and mechanical properties. For the above reasons, the objective of the present study was to investigate macrophage function on one promising type of nano‐implant material for orthopedic applications (carbon nanotubes microscopically aligned on polymers). To align carbon nanotubes on polymers, a novel imprinting method placing carbon nanotubes in grids of defined spacings (from 30 to 100 μm) on a polymer matrix was developed. In this study, the selective adhesion and proliferation of macrophages after 4 h, 24 h, and 4 days on aligned regions of a currently implanted polymer (specifically, polycarbonate urethane) compared to aligned carbon nanotube patterns were found. That is, decreased macrophage functions were observed in this study on aligned regions of carbon nanotubes compared to polycarbonate urethane. The present in vitro study, thus, provided evidence of the ability of carbon nanotubes to down‐regulate macrophage adhesion and proliferation which is important to decrease a harmful persistence wound‐healing reaction to orthopedic implants. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Novel hydroxyapatite/carboxymethylchitosan composite scaffolds prepared through an innovative “autocatalytic” electroless coprecipitation route
Authors: Oliveira J. M. , Costa S. A. , Leonor I. B. , Malafaya P. B. , Mano J. F. , Reis R. L.
Published: February 2008

A developmental composite scaffold for bone tissue engineering applications composed of hydroxyapatite (HA) and carboxymethylchitosan (CMC) was obtained using a coprecipitation method, which is based on the “autocatalytic” electroless deposition route. The results revealed that the pores of the scaffold were regular, interconnected, and possess a size in the range of 20–500 μm. Furthermore, the Fourier transform infra‐red spectrum of the composite scaffolds exhibited all the characteristic peaks of apatite, and the appearance of typical bands from CMC, thus showing that coprecipitation of both organic and inorganic phases was effective. The X‐ray diffraction pattern of composite scaffolds demonstrated that calcium‐phosphates consisted of crystalline HA. From microcomputed tomography analysis, it was possible to determine that composite scaffolds possess a 58.9% ± 6% of porosity. The 2D morphometric analysis demonstrated that on average the scaffolds consisted of 24% HA and 76% CMC. The mechanical properties were assessed using compressive tests, both in dry and wet states. Additionally, in vitro tests were carried out to evaluate the water‐uptake capability, weight loss, and bioactive behavior of the composite scaffolds. The novel hydroxyapatite/carboxymethylchitosan composite scaffolds showed promise whenever degradability and bioactivity are simultaneously desired, as in the case of bone tissue‐engineering scaffolding applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Design and characterization of a novel chitosan/nanocrystalline calcium phosphate composite scaffold for bone regeneration
Authors: Chesnutt Betsy M. , Viano Ann M. , Yuan Youling , Yang Yunzhi , Guda Teja , Appleford Mark R. , Ong Joo L. , Haggard Warren O. , Bumgardner Joel D.
Published: February 2008

To meet the challenge of regenerating bone lost to disease or trauma, biodegradable scaffolds are being investigated as a way to regenerate bone without the need for an auto‐ or allograft. Here, we have developed a novel microsphere‐based chitosan/nanocrystalline calcium phosphate (CaP) composite scaffold and investigated its potential compared to plain chitosan scaffolds to be used as a bone graft substitute. Composite and chitosan scaffolds were prepared by fusing microspheres of 500–900 μm in diameter, and porosity, degradation, compressive strength, and cell growth were examined. Both scaffolds had porosities of 33–35% and pore sizes between 100 and 800 μm. However, composite scaffolds were much rougher and, as a result, had 20 times more surface area/unit mass than chitosan scaffolds. The compressive modulus of hydrated composite scaffolds was significantly higher than chitosan scaffolds (9.29 ± 0.8 MPa vs. 3.26 ± 2.5 MPa), and composite scaffolds were tougher and more flexible than what has been reported for other chitosan‐CaP composites or CaP scaffolds alone. Using X‐ray diffraction, scaffolds were shown to contain partially crystalline hydroxyapatite with a crystallinity of 16.7% ± 6.8% and crystallite size of 128 ± 55 nm. Fibronection adsorption was increased on composite scaffolds, and cell attachment was higher on composite scaffolds after 30 min, although attachment rates were similar after 1 h. Osteoblast proliferation (based on dsDNA measurements) was significantly increased after 1 week of culture. These studies have demonstrated that composite scaffolds have mechanical properties and porosity sufficient to support ingrowth of new bone tissue, and cell attachment and proliferation data indicate composite scaffolds are promising for bone regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Preparation and properties of porous microspheres made from borate glass
Authors: Conzone Samuel D. , Day Delbert E.
Published: February 2008

Dysprosium lithium‐borate glass microspheres and particles, ranging from 45 to 150 μm in diameter, were reacted with a 0.25M phosphate solution at 37°C, whose pH was either 3 or 8.8. The glass reacted nonuniformly and was converted into a porous, amorphous, hydrated, dysprosium phosphate reaction product. The amorphous product had the same volume and shape (pseudomorphic) as the unreacted glass, and could be dried without cracking. After heating at 300°C for 1 h, the amorphous reaction product had a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and nominal crushing strength of ≈10 MPa. When the reaction product was heated to 600°C for 15 min, the specific surface area decreased to ≈90 m2/g and the nominal crushing strength increased to 35 MPa. Heating above 615°C converted the amorphous dysprosium phosphate product into crystalline DyPO4, which contained open porosity until heated above 800°C for 15 min. Highly porous materials of different chemical composition can be prepared by chemically reacting a borate‐based glass with an aqueous solution at low‐temperature (<100°C). These highly porous materials are easy to process, and are considered candidates for controlled drug delivery, catalysis, chromatographic separation, filtration, and as bioactive materials. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Adsorbed serum albumin is permissive to macrophage attachment to perfluorocarbon polymer surfaces in culture
Authors: Godek M. L. , Michel R. , Chamberlain L. M. , Castner D. G. , Grainger D. W.
Published: February 2008

Monocyte/macrophage adhesion to biomaterials, correlated with foreign body response, occurs through protein‐mediated surface interactions. Albumin‐selective perfluorocarbon (FC) biomaterials are generally poorly cell‐conducive because of insufficient receptor‐mediated surface interactions, but macrophages bind to albumin‐coated substrates and also preferentially to highly hydrophobic fluorinated surfaces. Bone marrow macrophages (BMMO) and IC‐21, RAW 264.7, and J774A.1 monocyte/macrophage cells were cultured on FC surfaces. Protein deposition onto two distinct FC surfaces from complex and single‐component solutions was tracked using fluorescence and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) methods. Cell adhesion and growth on protein pretreated substrates were compared by light microscopy. Flow cytometry and integrin‐directed antibody receptor blocking were used to assess integrins critical for monocyte/macrophage adhesion in vitro. Albumin predominantly adsorbs onto both FC surfaces from 10% serum. In cultures preadsorbed with albumin or serum‐dilutions, BMMO responded similar to IC‐21 at early time points. Compared with Teflon® AF, plasma‐polymerized FC was less permissive to extended cell proliferation. The β2 integrins play major roles in macrophage adhesion to FC surfaces: antibody blocking significantly disrupted cell adhesion. Albumin‐mediated cell adhesion mechanisms to FC surfaces could not be clarified. Primary BMMO and secondary IC‐21 macrophages behave similarly on FC surfaces, regardless of preadsorbed protein biasing, with respect to adhesion, cell morphology, motility, and proliferation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Enhanced smooth muscle cell adhesion and proliferation on protein‐modified polycaprolactone‐based copolymers
Authors: Bramfeldt Hanna , Vermette Patrick
Published: February 2008

Smooth muscle cells (SMC) were cultured for up to 6 days on copolymer films fabricated from a PCL‐PEG‐PCL block copolymer or P(ε‐CL‐co‐D,L‐LA)‐PEG‐P(ε‐CL‐co‐D,L‐LA), named P(100/0) and P(70/30), respectively. The films were modified by aminolysis using 1,6‐hexanediamine, and fibronectin, fibrinogen, or fibrin layers were subsequently immobilized by physisorption or by covalent coupling using imidoester chemistry. Immobilization of all the tested proteins resulted in significantly enhanced cell adhesion on these polymers. Moreover, we found that covalently immobilized proteins supported significantly greater cell proliferation than physisorbed proteins over 6 days. SMC cultured on P(100/0) films modified by covalently attached fibronectin or fibrin layers proliferated at a rate comparable to that observed on control tissue culture polystyrene. The proposed surface modification schemes were much less efficient in improving cell attachment and proliferation on P(70/30) films. However, prewetting P(70/30) with a phosphate buffer prior to aminolysis significantly improved cell numbers following immobilization of fibronectin. Immunostaining of smooth muscle‐specific α‐actin of SMC grown on protein‐modified P(100/0) 8 h and 48 h after cell seeding, confirmed preserved SMC phenotype on all modified surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In vitro investigation of maleated poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) for its biocompatibility to mouse fibroblast L929 and human microvascular endothelial cells
Authors: Li Xiao‐Tao , Sun Jie , Chen Song , Chen Guo‐Qiang
Published: February 2008

Poly (3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHHx), a polyester with strong mechanical properties and biocompatibility, is a member of microbial polyhydroxyalkanoates (PHA) family. Maleic anhydride was used to graft PHBHHx to form maleated PHBHHx (Ma‐PHBHHx). Ma‐PHBHHx with a graft degree of 0.59% was found to be more thermo‐stable in comparison with PHBHHx. In vitro study demonstrated that the biocompatibility to mouse fibroblast L929 and human microvascular endothelial cells (HMEC) was improved in different degrees on Ma‐PHBHHx films and scaffolds. Compared with their growth on PHBHHx, L929 and HMEC grown on Ma‐PHBHHx films and scaffolds showed ∼120% and 260% more in proliferation rates, respectively. Morphology study suggested that fine whorl‐like surface structures with porosities on Ma‐PHBHHx films attributed to MA grafting would be better for cell attachment and proliferation. Ma‐PHBHHx scaffolds prepared by thermally induced phase separation (TIPS) with increased porosity, hydrophilicity, surface energy, and charges also were more favorable for cell growth. In addition, Ma‐PHBHHx showed an accelerated degradation incubation in SBF at 37°C, losing 21.4% of its original weight after 21 weeks while PHBHHx just lost 7.3%. Based on the improved biocompatibility, reasonable mechanical properties as well as accelerated biodegradation, Ma‐PHBHHx has shown advantages over PHBHHx as a biomaterial for biomedical applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Electrocoating of stainless steel coronary stents for extended release of paclitaxel
Authors: Okner R. , Oron M. , Tal N. , Nyska A. , Kumar N. , Mandler D. , Domb A. J.
Published: February 2008

Nonbiodegradable polymer coating based on N‐(2‐carboxyethyl)pyrrole (PPA) and butyl ester of PPA (BuOPy) were successfully electrodeposited on a stainless steel stent surface using cyclic voltammetry. Chemical composition of the coating was examined by X‐ray photoelectron spectroscopy. Polymer stability was examined by immersing the coated stent into 1:1 solution of fetal calf serum:seline solution up to 1 year and implantation subcutaneously in mouse for 1 week. Morphology changes were then recorded by scanning electron microscopy. Paclitaxel loading was carried out by immersion into drug solution and its release was detected by HPLC. The results show that thin (single micrometers), uniform coating with various morphology and hydrophobicity can be created by electrochemical deposition. The polymer did not show significant histopathological or morphological changes in vitro and in vivo. The surface properties allow loading appropriate amounts of paclitaxel and release it slowly up to a month. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Increased chondrocyte adhesion on nanotubular anodized titanium
Authors: Burns Kevin , Yao Chang , Webster Thomas J.
Published: February 2008

Previous studies have demonstrated increased osteoblast (bone‐forming cells) functions (including adhesion, synthesis of intracellular collagen, alkaline phosphatase activity, and deposition of calcium‐containing minerals) on titanium anodized to possess nanometer features compared with their unanodized counterparts. Such titanium materials were anodized to possess novel nanotubes also capable of drug delivery. Since titanium has not only experienced wide spread commercial use in orthopedic but also in cartilage applications, the objective of the present in vitro study was for the first time to investigate chondrocyte (cartilage synthesizing cells) functions on titanium anodized to possess nanotubes. For this purpose, titanium was anodized in dilute hydrofluoric acid at 20 V for 20 min. Results showed increased chondrocyte adhesion on anodized titanium with nanotube structures compared with unanodized titanium. Importantly, the present study also provided evidence why. Since material characterization studies revealed significantly greater nanometer roughness and similar chemistry as well as crystallinity between nanotubular anodized and unanodized titanium, the results of the present study highlight the importance of the nanometer roughness provided by anodized nanotubes on titanium for enhancing chondrocyte adhesion. In this manner, the results of the present in vitro study indicated that anodization might be a promising quick and inexpensive method to modify the surface of titanium‐based implants to induce better chondrocyte adhesion for cartilage applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Minimum detectable difference of MR diffusion maps in acute ischemic stroke
Authors: Harris Ashley D. , Govindaraj Mirthula , Frayne Richard
Published: February 2008

Purpose

To determine the minimum detectable difference (MDD) and investigate variability of region‐of‐interest (ROI) analysis of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in acute ischemic stroke.

Materials and Methods

Ten patients with acute stroke (<24 hours) and moderate‐to‐large infarcts were imaged using a fast diffusion tensor technique. Four observers repeated three trials, during which each of two ROI types (free‐hand polygon and ellipse) were drawn in white and gray matter (WM and GM) on FA and ADC maps. Analysis‐of‐variance techniques examined tissue and ROI type effects as well as inter‐ and intraobserver variability. F‐tests examined the variability differences between ROI types.

Results

The MDD for ADC was 0.160 × 10−3 mm2 s−1 in WM and 0.212 × 10−3 mm2 s−1 in GM. The FA MDD was 0.19 in WM and 0.10 in GM. Tissue but not ROI type affected the mean values for both ADC and FA maps. Intraobserver reliability was substantial, while interobserver reliability was poor‐to‐moderate. No variability differences were found by ROI types.

Conclusion

The MDD for WM and GM in normal and ischemic tissue were calculated. Inter‐ and intraobserver variability and tissue type affect ROI analysis of ADC and FA maps. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Commitment, procedural fairness, and organizational citizenship behavior: a multifoci analysis
Authors: Lavelle James J. , Brockner Joel , Konovsky Mary A. , Price Kenneth H. , Henley Amy B. , Taneja Aakash , Vinekar Vishnu
Published: February 2008

Research on commitment, procedural fairness, and organizational citizenship behavior (OCB) suggests that employees maintain distinct beliefs about, and direct behaviors towards, multiple targets in the workplace (e.g., the organization as a whole, their supervisor, and fellow workgroup members). The present studies were designed to test for “target similarity effects,” in which the relationships between commitment, procedural fairness, and OCB were expected to be stronger when they referred to the same target than when they referred to different targets. As predicted, we found that: (1) the positive relationship between commitment and OCB, and (2) the mediating effect of commitment on the positive relationship between procedural fairness and OCB, was particularly likely to emerge when the constructs were in reference to the same target. Support for these target similarity effects was found among layoff survivors (Study 1) and student project teams (Study 2). Theoretical and practical implications are discussed, as are limitations of the studies and suggestions for future research. Copyright © 2008 John Wiley & Sons, Ltd.
The North Atlantic Oscillation and European vegetation dynamics
Authors: Gouveia Célia , Trigo Ricardo M. , DaCamara Carlos C. , Libonati Renata , Pereira José M. C.
Published: February 2008

The relationship between vegetation greenness and the North Atlantic Oscillation (NAO) is assessed over Europe. The study covers the 21‐year period from 1982 to 2002 and is based on monthly composites of the Normalised Difference Vegetation Index (NDVI) and Brightness Temperature from the Global Inventory Monitoring and Modelling System (GIMMS) as well as on monthly precipitation from the Global Precipitation Climatology Centre (GPCC).

A systematic analysis is first performed of point correlation fields over the 21‐year period between the winter NAO index and spring and summer NDVI, followed by an assessment of the vegetation response to precipitation and temperature conditions in winter, over two contrasting regions, namely the Iberian Peninsula and Northeastern Europe. Finally, the impact of NAO on vegetation dynamics over the two regions is evaluated by studying the corresponding annual cycles of NDVI and comparing their behaviour for years associated with opposite NAO phases.

Over the Iberian Peninsula there is strong evidence that positive (negative) values of winter NAO induce low (high) vegetation activity in the following spring and summer seasons. This feature is mainly associated with the impact of NAO on winter precipitation, together with the strong dependence of spring and summer NDVI on water availability during the previous winter. Northeastern Europe shows a different behaviour, with positive (negative) values of winter NAO inducing high (low) values of NDVI in spring, but low (high) values of NDVI in summer. This behaviour mainly results from the strong impact of NAO on winter temperature, associated with the critical dependence of vegetation growth on the combined effect of warm conditions and water availability during the winter season. Copyright © 2008 Royal Meteorological Society
Hyaluronic acid inhibits mRNA expression of proinflammatory cytokines and cyclooxygenase‐2/prostaglandin E2 production via CD44 in interleukin‐1‐stimulated subacromial synovial fibroblasts from patients with rotator cuff disease
Authors: Mitsui Yasuhiro , Gotoh Masafumi , Nakama Kenjirou , Yamada Tetsu , Higuchi Fujio , Nagata Kensei
Published: February 2008

A growing body of evidence supports use of intraarticular hyaluronic acid (HA) injection in patients with rotator cuff disease. However, the mechanism of its anti‐inflammatory action has not been clarified. We examined the effects of HA on the expression of mRNAs for proinflammatory cytokines (IL‐1β, IL‐6, and TNF‐α and COX‐2/PGE2 production in IL‐1‐stimulated subacromial‐synovium fibroblasts (SSF) derived from patients with rotator cuff disease. Various concentrations of HA were added to monolayer SSF cultures in the presence of IL‐1β. Gene expression levels were analyzed by quantitative real‐time reverse transcription‐polymerase chain reaction. Intracellular production of COX‐2 was identified by Western blotting. PGE2 concentrations in the culture media were measured by ELISA. CD44 blocking with OS/37 was performed to investigate the mechanism of action of HA. Immunofluorescence cytochemistry confirmed binding of HA and the presence of CD44 on SSF. Exogenous HA significantly and dose‐dependently decreased expression of proinflammatory cytokine mRNAs and COX‐2/PGE2 production in IL‐1‐stimulated SSF. Pretreatment with OS/37 reversed the inhibitory effects of HA. These results provide a basis for explaining why HA is effective for the treatment of rotator cuff disease. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1032–1037, 2008
Impact of MHC mismatch and freezing on bone graft incorporation: An experimental study in rats
Authors: Reikerås Olav , Shegarfi Hamid , Naper Christian , Reinholt Finn P. , Rolstad Bent
Published: February 2008

Cortical bone graft failure develops for poorly defined reasons, and the effects of the immune responses on the incorporation of an allograft are less clear. In a rat model of tibial allotransplantation, we have studied biometric and histological changes of the graft and the humoral immune response against it. We have also compared fresh with prefrozen grafts to study putative effects of freezing on the healing of the graft and the immune response against it. Fresh and frozen cortical bone grafts matched or mismatched for major histocompatibility complex antigens (syngeneic and allogeneic grafts) were implanted in an 8‐mm segmental defect in the tibia. The construct was stabilized with intramedullary nailing. Incorporation of the graft was assessed with use of conventional radiography, micro computed tomography (CT(, biomechanical testing and histological examination. The immune response was evaluated by monitoring distribution of leukocytes in the blood and by measuring antibodies in a tailor‐made fluorescence activating cell scanning (FACS( analysis. We found that the fresh syngeneic grafts were well integrated after 8 weeks with intact bone cells. In the fresh allogeneic grafts, all cells were dead with radiological signs of resorption, and mechanical testing indicated failure of incorporation. The frozen grafts showed poorer overall reconstruction than the fresh syngeneic grafts, but the incorporation was better than the fresh allogeneic grafts. A measurable alloantibody response was only detected after fresh allografting. The combined results suggest that freezing of bone allograft impedes the antibody response against major histocompatibility complex (MHC( antigens and improves incorporation, but frozen allografts still perform poorer than do frozen syngeneic grafts. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:925–931, 2008
Apoptosis of human intervertebral discs after trauma compares to degenerated discs involving both receptor‐mediated and mitochondrial‐dependent pathways
Authors: Tschoeke Sven K. , Hellmuth Markus , Hostmann Arwed , Robinson Yohan , Ertel Wolfgang , Oberholzer Andreas , Heyde Christoph‐E.
Published: February 2008

Post‐traumatic disc degeneration with consecutive loss of reduction and kyphosis remains a debatable issue within both the operative and nonoperative treatment regimen of thoracolumbar spine fractures. Intervertebral disc (IVD) cell apoptosis has been suggested to play a vital role in promoting the degeneration process. To evaluate and compare apoptosis‐regulating signaling mechanisms, IVDs were obtained from patients with thoracolumbar spine fractures (n = 21), patients suffering from symptomatic IVD degeneration (n = 6), and from patients undergoing surgical resection of a primary vertebral tumor (n = 3 used as control samples). All tissues were prospectively analyzed in regards to caspase‐3/7, ‐8, and ‐9 activity, apoptosis‐receptor expression levels, and gene expression of the mitochondria‐bound apoptosis‐regulating proteins Bax and Bcl‐2. Morphologic changes characteristic for apoptotic cell death were confirmed by H&E staining. Statistical significance was designated at p < 0.05 using the Student's t‐test. Both traumatic and degenerative IVD demonstrated a significant increase of caspase‐3/7 activity with evident apoptosis. Although caspase‐3/7 activation was significantly greater in degenerated discs, both showed equally significant activation of the initiator caspases 8 and 9. Traumatic IVD alone demonstrated a significant increase of the Fas receptor (FasR), whereas the TNF receptor I (TNFR I) was equally up‐regulated in both morbid IVD groups. Only traumatic IVD showed distinct changes in up‐regulated TNF expression, in addition to significantly down‐regulated antiapoptotic Bcl‐2 protein. Our results suggest that post‐traumatic disc changes may be promoted and amplified by both the intrinsic mitochondria‐mediated and extrinsic receptor‐mediated apoptosis signaling pathways, which could be, in part, one possible explanation for developing subsequent disc degeneration. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:999–1006, 2008
The human anterior cruciate ligament: Sex differences in ultrastructure and correlation with biomechanical properties
Authors: Hashemi Javad , Chandrashekar Naveen , Mansouri Hossein , Slauterbeck James R. , Hardy Daniel M.
Published: February 2008

The purpose of this study was to investigate the existence of sex‐based differences in the ultrastructural characteristics of the human anterior cruciate ligament (ACL) as the underlying cause of differences in the structural and mechanical properties between sexes. The ACL of six male and six female cadaveric donors were randomly chosen from a pool of 10 male and 10 female ACLs that had previously been tested for their structural and mechanical properties. Eighteen tissue samples from the distal, proximal, and middle sections of the anteromedial and posterolateral bundles were analyzed by transmission electron microscopy. Female ACLs exhibited both lower fibril concentration and lower percent area occupied by collagen fibrils (p < 0.05) compared to males. There was also a difference in the fibril diameters (p < 0.05); donor age, height, body mass, and body mass index contributed significantly to this difference. In females, ACL stiffness and modulus of elasticity were highly correlated to fibril concentration (r = 0.96 and 0.97, respectively); in males ACL failure load and strength were highly correlated to percent area occupied by collagen (r = 0.96 and 0.96, respectively). These differences in ultrastructure may underlie differences in ACL properties between sexes. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:945–950, 2008
Functional mapping of carious enamel in human teeth with Raman microspectroscopy
Authors: Kinoshita H. , Miyoshi N. , Fukunaga Y. , Ogawa T. , Ogasawara T. , Sano K.
Published: February 2008

We employed Raman microspectroscopy to measure the Raman spectra of phosphate in sound and carious tooth substance. The peak intensity at 960 cm−1 of the phosphate (PO43−) symmetric stretching vibrational mode (υ1) in sound enamel was stronger than that of sound dentin, which indicated that sound enamel contained more phosphate than sound dentin. Furthermore, the element analysis of phosphate in sound teeth substance, measured using a scanning electron microscope (SEM) equipped with an energy dispersive X‐ray spectroscope (EDX), gave similar results to those of the Raman measurement. In addition, the border between sound enamel and dentin was clearly demonstrated by mapping the image of the Raman spectrum of phosphate. The mapping image of phosphate in the carious enamel region revealed a heterogeneous low Raman spectrum intensity of phosphate in the area surrounding carious enamel; this finding indicates that phosphate had dissolved from the tooth substance in such areas. In contrast with the decrease in the Raman spectrum intensity of phosphate, the intensity of amide I increased mainly in the low‐phosphate area. Although it remains very difficult to clinically identify the accurate border between sound and carious tooth substance, this distinction may be enabled by using the Raman spectrum of carious tooth substance. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of hafnium tungstate by a CO2 laser and its microstructure and Raman spectroscopic study
Authors: Liang E. J. , Wang J. P. , Xu E. M. , Du Z. Y. , Chao M. J.
Published: February 2008

Densely packed hafnium tungstate blocks were synthesized by rapid solidification with a CO2 laser. It is shown that the optimum synthesis conditions for HfW2O8 are around 700 W laser power and 1 mm/s scan speed. Scanning electron microscopy (SEM) observation shows that the blocks consist of oriented nano‐threads/rods that grew horizontally on the surface region and vertically in the interior. The orientations of the nanostructures are governed by the heat transfer directions on the surface and in the interior. Raman spectroscopic and X‐ray diffraction studies show that the samples solidified in the cubic structure with minor contents of the orthorhombic phase. This is explained by a compressive stress induced during the rapid solidification process due to a sudden drop of temperature of the molten pool to the ambient. The stress is estimated to be about 0.6 GPa by comparison with high‐pressure Raman study. Some specific Raman bands appear in the samples synthesized with the laser synthetic route but not in the sample by solid‐state reaction. Copyright © 2008 John Wiley & Sons, Ltd.
The Goodmanham plane: Raman spectroscopic analysis of a Roman ivory artefact
Authors: Long D. A. , Edwards H. G. M. , Farwell D. W.
Published: February 2008

Raman spectroscopy has been applied to the study of the exceptional ivory stock of an archaeological discovery of great importance for the history of woodworking tools: a virtually complete Roman plane that was found in a late fourth century A.D. context in North Yorkshire, UK, in A.D. 2000. An assessment has been made of the viability of Raman spectroscopy for the identification of ivories from archaeological excavations and comparisons made with similar studies of modern specimens. All of the attributed ivory specimens studied have suffered from deterioration in their burial environment, and severe degradation of their proteinaceous component was observed. In addition, spectral quality was affected through the absorption of fluorescent materials from their environment, and from the presence of emergency conservation procedures undertaken to preserve the integrity of very fragile specimens. The spectra of ivories dating from about 2000 years ago varied considerably because some specimens had experienced an almost complete leaching‐out of collagen, whereas in others, the degraded protein was still substantially identifiable. Generally, however, the protocols used successfully for the identification of modern ivories and for an assignment of their mammalian species were not transferable into archaeological ivory identification and classification because of the collagen degradation and decreased spectral quality. Copyright © 2008 John Wiley & Sons, Ltd.
Gas chromatography/mass spectrometry of oils and oil binders in paintings
Authors: Blaško Jaroslav , Kubinec Robert , Husová Barbora , Přikryl Petr , Pacáková Věra , Štulík Karel , Hradilová Janka
Published: February 2008

A GC/MS procedure has been developed, optimized, and applied to characterization of oil binders in paintings. The procedure involves hydrolysis of lipids to fatty acids (FAs) and derivatization of FAs to fatty acid methyl esters (FAMEs) by a solution of sodium methanolate in methanol at an elevated temperature. FAMEs are analyzed by temperature‐programed GC followed by full‐scan MS. Old and dried samples are subjected to extraction of nonpolymerized FAMEs into dichloromethane prior to hydrolysis. The method provides a good repeatability of results and has been applied to the characterization of common plant oils used in paintings, to commercial oil and tempera paints, to model painting samples, and to samples taken from real paintings. The fresh oils and binders can readily be identified and characterized. The ratio of the methyl esters of palmitic and stearic acids can be used to characterize oil binders in old works of art.
Optimization of a liquid chromatographic separation for the simultaneous determination of four anthracyclines and their respective 13‐S‐dihydro metabolites
Authors: Maudens Kristof E. , Stove Christophe P. , Lambert Willy E.
Published: February 2008

The optimization of a liquid chromatographic separation of four anthracyclines (doxorubicin, epirubicin, daunorubicin and idarubicin) and their respective 13‐S‐dihydro metabolites (doxorubicinol, epirubicinol, daunorubicinol and idarubicinol) is described. Inclusion of epidaunorubicin in the assay allows internal standardization. Potential chromatographic interference of aglycones (doxorubicinone, daunorubicinone, idarubicinone, doxorubicinolone, daunorubicinolone and idarubicinolone) was investigated and tackled. The analyses were performed on a C18 RP column and gradient elutions were performed with a mixture of 0.1% formic acid in water and 0.1% formic acid in ACN. The analytes were measured by fluorescence detection with an excitation wavelength of 480 nm and emission wavelength of 555 nm, respectively. The separation will potentially allow a broad field of applications, ranging from therapeutic drug monitoring and kinetic studies in cancer patients to monitoring hospital personnel and effluents.
Volatile flavour constituent patterns of Terras Madeirenses red wines extracted by dynamic headspace solid‐phase microextraction
Authors: Perestrelo Rosa , Caldeira Michael , Rodrigues Freddy , Câmara José S.
Published: February 2008

A suitable analytical procedure based on static headspace solid‐phase microextraction (SPME) followed by thermal desorption gas chromatography–ion trap mass spectrometry detection (GC–ITDMS), was developed and applied for the qualitative and semi‐quantitative analysis of volatile components of Portuguese Terras Madeirenses red wines. The headspace SPME method was optimised in terms of fibre coating, extraction time, and extraction temperature. The performance of three commercially available SPME fibres, viz. 100 μm polydimethylsiloxane; 85 μm polyacrylate, PA; and 50/30 μm divinylbenzene/carboxen on polydimethylsiloxane, was evaluated and compared. The highest amounts extracted, in terms of the maximum signal recorded for the total volatile composition, were obtained with a PA coating fibre at 30°C during an extraction time of 60 min with a constant stirring at 750 rpm, after saturation of the sample with NaCl (30%, w/v). More than sixty volatile compounds, belonging to different biosynthetic pathways, have been identified, including fatty acid ethyl esters, higher alcohols, fatty acids, higher alcohol acetates, isoamyl esters, carbonyl compounds, and monoterpenols/C13‐norisoprenoids.
Which type of tourism matters to the regional economic growth? The cases of Spain and Italy
Authors: Cortés‐Jiménez Isabel
Published: February 2008

Recently, the attention given to the importance of tourism in economic growth has significantly increased. However, research in this area mainly refers to international tourism and to the national level. This paper focuses on the influence of tourism on the economic growth of Spanish and Italian regions. Both international and domestic tourism are analysed and geographical location criteria are considered. Dynamic panel data techniques are applied. The results reveal that both international and domestic tourism have a significant and positive role for regional economic growth in Spain and Italy, although the pattern of these effects differs among different types of region. Copyright © 2008 John Wiley & Sons, Ltd.
Economic measures of tourism yield: what markets to target?
Authors: Dwyer Larry , Forsyth Peter
Published: February 2008

An understanding of the yield potential of different source markets and segments can underpin destination marketing by both public and private sector organisations. The standard yield measure relates to expenditure injected into a destination from different market segments. This measure has several limitations, which are discussed in the paper. With the increasing sophistication of economic models such as computable general equilibrium, models, it is now feasible to develop new and more useful measures of tourism yield, which directly measure the gains to different stakeholders. Several economy‐wide impact measures of yield are developed and contrasted for selected Australian inbound tourism markets. The measures produce conflicting signals for public and private sector tourism marketers and planners. The reward from further research in developing and operationalising yield measures is more informed policy‐making by destination managers in respect of destination marketing and new product development, resulting in greater economic gains from inbound tourism. Copyright © 2008 John Wiley & Sons, Ltd.
Tourism and internet adoption: a developing world perspective
Authors: Karanasios Stan , Burgess Stephen
Published: February 2008

This paper provides a new perspective of the realities faced by small tourism enterprises in the developing world. Given the well‐recognised value of the Internet in tourism, we sought to identify how entrepreneurs mitigate Internet adoption obstacles such as the inadequate and unreliable telecommunications infrastructure, the cost of the technology, and a lack of knowledge and skills that characterise developing nations. A qualitative study was performed on small tourism enterprises in rural and metropolitan areas of Malaysia and Ecuador. We found that entrepreneurs established ways to overcome obstacles, with some applying quite innovative solutions. This paper helps to understand the role of entrepreneurs in innovation adoption and improve knowledge of Internet appropriation among small tourism enterprises in developing nations. A number of transferable lessons are identified. Copyright © 2008 John Wiley & Sons, Ltd.
Exploring the role of expedition staff in volunteer tourism
Authors: Coghlan Alexandra
Published: February 2008

Conservation volunteer tourism (VT) (or nature conservation expedition)‐related organisations can provide a meeting point for both tourists and field‐based scientists. Expedition leaders should be aware of the needs of the volunteer tourists that can be fulfilled through VT. It appears that the role of expedition leaders is central to the successful execution of the VT expedition. This study aimed to understand the expedition leaders' perceptions of VT, their perspective of the expectations of their volunteer tourists and their requirements of the volunteers, and assess how volunteers perform with regard to those requirements. The results suggest that there may be some differences in perceptions between leaders and volunteer tourists that may affect the success of the expedition. Copyright © 2008 John Wiley & Sons, Ltd.