bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐resolution modelling of the potential impact of land surface conditions on regional climate over Indochina associated with the diurnal precipitation cycle
Authors: Takahashi Hiroshi G. , Yoshikane Takao , Hara Masayuki , Takata Kumiko , Yasunari Tetsuzo 
Published: March 2010

AbstractThis study examined the impact of changes in land surface conditions on regional climate over Indochina using a high‐resolution regional climate model. Anthropogenically induced land surface changes are going on in this part of tropical Southeast Asia. Because a previous study suggested that deforestation in this area affected September precipitation, we chose September as the study period. We performed a control simulation (CTL) driven by reanalysis data combined with current land use and predicted soil moisture data. The CTL reproduced the spatial distribution of total precipitation well. In addition, it also simulated a distinct diurnal cycle of precipitation that was previously reported in observational studies. Two sensitivity experiments, assuming wetter and drier land surface conditions over the Khorat Plateau (northeast Thailand) compared with the current land surface condition, were conducted and examined the impact of land surface changes on precipitation. The results indicated that drier land surface conditions increased precipitation over the disturbed region. A pronounced increase in precipitation was found only during nighttime, which coincided with the peak in the climatological diurnal precipitation cycle. Climatologically, the diurnal peak in precipitation occurs from evening to early morning over the Khorat Plateau. Drier conditions intensified the diurnal variation of precipitable water associated with the thermally induced local circulation responsible for a horizontal gradient of near‐surface temperature. The effects of land use and land cover changes in the tropics are shown to be strongly related to the diurnal precipitation cycle. Copyright © 2010 Royal Meteorological Society
Cross‐linking affects cellular condensation and chondrogenesis in type II collagen‐GAG scaffolds seeded with bone marrow‐derived mesenchymal stem cells
Authors: Vickers Scott M. , Gotterbarm Tobias , Spector Myron 
Published: March 2010

AbstractThe formation of cartilaginous tissue by chondroprogenitor cells, whether in vivo or in vitro, appears to require a critical initial stage of “condensation” in which intercellular space is reduced through an aggregation of cells, leading to development of cell‐to‐cell junctions followed by chondrocytic differentiation. The objective of this study was to investigate the association of aggregation (condensation) of mesenchymal stem cell (MSCs) and chondrogenesis in vitro. Previous work with chondrocytes indicated that the cross‐link density and related cell‐mediated contraction of collagen scaffolds significantly affects cartilaginous tissue formation within the cell‐seeded construct. Based on this finding, we hypothesized that the cell‐aggregating effect of the contraction of MSC‐seeded collagen scaffolds of lower cross‐link density favors chondrogenesis; scaffolds of higher cross‐link density, which resist cell‐mediated contraction, would demonstrate a lower cell number density (i.e., subcritical packing density) and less cartilage formation. Type II collagen–GAG scaffolds, chemically cross‐linked to achieve a range of cross‐link densities, were seeded with caprine MSCs and cultured for 4 weeks. Constructs with low cross‐link densities experienced cell‐mediated contraction, increased cell number densities, and a greater degree of chondrogenesis (indicated by the chondrocytic morphology of cells, and synthesis of GAG and type II collagen) compared to more highly cross‐linked scaffolds that resisted cellular contraction. These results provide a foundation for further investigation of the mechanisms by which condensation of mesenchymal cells induces chondrogenesis in this in vitro model, and may inform cross‐linking protocols for collagen scaffolds for use in cartilage tissue engineering. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1184–1192, 2010
Bone deposition, bone resorption, and osteosarcoma
Authors: Toledo Sílvia Regina Caminada , Oliveira Indhira Dias , Okamoto Oswaldo Keith , Zago Marco Antonio , de Seixas Alves Maria Teresa , Filho Reynaldo Jesus Garcia , Macedo Carla Renata Pacheco Donado , Petrilli Antonio Sergio 
Published: March 2010

AbstractBone deposition and bone resorption are ongoing dynamic processes, constituting bone remodeling. Some bone tumors, such as osteosarcoma (OS), stimulate focal bone deposition. OS is the most common primary bone tumor in children and young adults. A complex network of genes regulates bone remodeling and alterations in its expression levels can influence the genesis and progression of bone diseases, including OS. We hypothesized that the expression profiles of bone remodeling regulator genes would be correlated with OS biology and clinical features. We used real‐time PCR to evaluate the mRNA levels of the tartrate‐resistant acid phosphatase (ACP5), colony stimulating factor‐1 (CSF1R), bone morphogenetic protein 7 (BMP7), collagen, type XI, alpha 2 (COL11A2), and protein tyrosine phosphatases zeta 1 (PTPRZ1) genes, in 30 OS tumor samples and correlated with clinical and histological data. All genes analyzed, except CSF1R, were differentially expressed when compared with normal bone expression profiles. In our results, OS patients with high levels of COL11A2 mRNA showed worse overall (p = 0.041) and event free survival (p = 0.037). Also, a trend for better overall survival was observed in patients with samples showing higher expression of BMP7 (p = 0.067). COL11A2 overexpression and BMP7 underexpression could collaborate to OS tumor growth, through its central role in bone remodeling process. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1142–1148, 2010
Diminished cartilage creep properties and increased trabecular bone density following a single, sub‐fracture impact of the rabbit femoral condyle
Authors: Borrelli Joseph , Zaegel Melissa A. , Martinez Mario D. , Silva Matthew J. 
Published: March 2010

AbstractTraumatic injury to articular cartilage can lead to post‐traumatic arthritis. We used a custom pendulum device to deliver a single, near‐fracture impact to the medial femoral condyles of rabbits. Impact was localized to a region ∼3 mm in diameter, and impact stress averaged ∼100 MPa. Animals were euthanized at 0, 1, and 6 months after impact. Cartilage mechanical properties from impacted and sham knees were evaluated by creep‐indentation testing, and periarticular trabecular bone was evaluated by microCT and histomorphometry. Impact caused immediate and statistically significant loss of cartilage thickness (−40% vs. sham) and led to a greater than twofold increase in creep strain. From 0 to 6 months after impact, the ability of cartilage to recover from creep deformation became significantly impaired (percent recovery different from control at 1 and 6 months). At 1 month, there was a 33% increase in the trabecular bone volume fraction of the epiphysis beneath the site of impact compared to control, and increased bone formation was observed histologically. Taken together, these findings demonstrate that a single, high‐energy impact below the fracture threshold leads to acute deleterious changes in the viscoelastic properties of articular cartilage that worsen with time, while at the same time stimulating increased bone formation beneath the impact site. Published by Wiley Periodicals, Inc. J Orthop Res 28:1307–1314, 2010
Mouse treadmill running enhances tendons by expanding the pool of tendon stem cells (TSCs) and TSC‐related cellular production of collagen
Authors: Zhang Jianying , Pan Tiffany , Liu Yan , Wang James H‐C. 
Published: March 2010

AbstractExercise is known to enhance tendon size and strength, but the stem cell‐based mechanisms for such exercise‐induced effects are largely unknown. This study aims to explore these mechanisms by using a mouse treadmill running model to examine the effects of exercise on newly discovered tendon stem cells (TSCs). After treadmill running, patellar TSCs (PTSCs) and Achilles TSCs (ATSCs) were isolated from the mice, and their proliferation was measured in vitro. We found that treadmill running nearly doubled proliferation rates of both PTSCs and ATSCs compared to cage control mice. Moreover, using a mixed tendon cell culture consisting of TSCs and tenocytes, cellular production of collagen was found to increase by 70% and 200% in PTSCs and ATSCs, respectively, from the treadmill running group over cells from the cage control group. These findings suggest that exercise exerts its anabolic effects on tendons at least in part by increasing proliferation to expand the pool of TSCs and also by increasing TSC‐related cellular production of collagen, the predominant component of tendons. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1178–1183, 2010
Median nerve deformation and displacement in the carpal tunnel during index finger and thumb motion
Authors: van Doesburg Margriet H. M. , Yoshii Yuichi , Villarraga Hector R. , Henderson Jacqueline , Cha Stephen S. , An Kai‐Nan , Amadio Peter C. 
Published: March 2010

AbstractThe purpose of this study was to investigate the deformation and displacement of the normal median nerve in the carpal tunnel during index finger and thumb motion, using ultrasound. Thirty wrists from 15 asymptomatic volunteers were evaluated. Cross‐sectional images during motion from full extension to flexion of the index finger and thumb were recorded. On the initial and final frames, the median nerve, flexor pollicis longus (FPL), and index finger flexor digitorum superficialis (FDS) tendons were outlined. Coordinate data were recorded and median nerve cross‐sectional area, perimeter, aspect ratio of the minimal‐enclosing rectangle, and circularity in extension and flexion positions were calculated. During index finger flexion, the tendon moves volarly while the nerve moves radially. With thumb flexion, the tendon moves volarly, but the median nerve moves toward the ulnar side. In both motions, the area and perimeter of the median nerve in flexion were smaller than in extension. Thus, during index finger or thumb flexion, the median nerve in a healthy human subject shifts away from the index finger FDS and FPL tendons while being compressed between the tendons and the flexor retinaculum in the carpal tunnel. We are planning to compare these data with measurements in patients with carpal tunnel syndrome (CTS) and believe that these parameters may be useful tools for the assessment of CTS and carpal tunnel mechanics with ultrasound in the future. Published by Wiley Periodicals, Inc. J Orthop Res 28:1387–1390, 2010
Individual susceptibility to periprosthetic osteolysis is associated with altered patterns of innate immune gene expression in response to pro‐inflammatory stimuli
Authors: Gordon Andrew , Greenfield Edward M. , Eastell Richard , Kiss‐Toth Endre , Wilkinson Jeremy Mark 
Published: March 2010

AbstractSusceptibility to osteolysis after total hip arthroplasty (THA) varies between individuals. We examined whether patients susceptible to osteolysis (group I, n = 34 subjects) after cemented Charnley THA have quantitatively different innate immune responses to pro‐inflammatory stimuli versus patients without this susceptibility (group II, n = 28 subjects) at a mean of 14 years after primary surgery. Extracted peripheral blood mononuclear cells were stimulated for 3 h using endotoxin (lipopolysaccharide—LPS, 100 ng/mL), endotoxin‐stripped titanium particles (Ti) or endotoxin‐stripped particles with adherent LPS added‐back (TI + LPS). Subjects returned 1 week later and the experimental protocol was repeated. Assays for mRNA induction for interleukin (IL)‐1α, IL‐1β, IL‐1Ra, IL‐6, IL‐10, IL‐18, and tumor necrosis factor (TNF) were made using quantitative real‐time PCR. Although baseline levels of mRNA expression were slightly lower in group I, inducibility of mRNA expression was markedly greater in group I versus group II for all cytokines in response to LPS or Ti + LPS, and for IL‐1α in response to Ti (P < 0.05). LPS or Ti + LPS stimulation also resulted in an increase in the IL‐1/IL‐1Ra mRNA ratio in group I versus group II (P < 0.05). mRNA induction was highly reproducible between subject visits (r > 0.7, P < 0.001). Osteolysis‐susceptible patients show repeatable, quantitatively different patterns of innate cytokine gene expression in response to pro‐inflammatory stimuli versus THA patients who do not display this susceptibility. These innate immune differences may contribute to the variation in osteolysis‐susceptibility observed clinically between individuals. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1127–1135, 2010
New evidence on the sequence of deglacial warming in the tropical Indian Ocean
Authors: Naidu P. Divakar , Govil Pawan 
Published: March 2010

AbstractThe transition from the Last Glacial Maximum to the Holocene was an internal of climate variability that was characterised by large spatial and temporal variations. Here we show that deglaciation warming in the northern Indian Ocean was initiated ca. 19 ka, which is contemporary with deglaciation warming in the Antarctica and Southern Ocean. A gradual warming occurred during the glacial/Holocene transition in the northern Indian Ocean, unlike the two‐step warming seen in Greenland and the North Atlantic. Synchronous deglacial warming ca. 19 ka in Antarctica and the northern Indian Ocean suggests a strong connection in the propagation of climate signals between Antarctica and the Indian Ocean, probably through the Indonesian Throughflow and/or Subantarctic Mode Water. Copyright © 2010 John Wiley & Sons, Ltd.
Nonlinear optical microscopy for drug delivery monitoring and cancer tissue imaging
Authors: Mouras Rabah , Rischitor G. , Downes A. , Salter D. , Elfick A. 
Published: March 2010

AbstractA multimodal nonlinear optical microscope that combines coherent anti‐Stokes Raman scattering (CARS), two‐photon excitation fluorescence (TPEF), second‐harmonic generation (SHG) and sum‐frequency generation (SFG) was developed and applied to image breast cancer tissue and MCF‐7 cells as well as monitoring anticancer drug delivery in live cells. TPEF imaging showed that drugs are preferentially localized in the cytoplasm and the nuclear envelope in resistant cells. Moreover, the extracellular matrix was observed by TPEF signals arising from elastin's autofluorescence and SHG signals from collagen fibrils in breast tissue sections. Additionally, CARS signals arising from proteins and (PO2)− allowed identification of tumors. Label‐free imaging with chemical contrast of significant components of cancer cells and tissue suggests the potential of multimodal nonlinear optical microscopy for early detection and diagnosis of cancer. Copyright © 2010 John Wiley & Sons, Ltd.
One‐pot synthesis of silver particle aggregation as highly active SERS substrate
Authors: Cai Zhicheng , Tian Chungui , Wang Lei , Zhou Wei , Wang Baoli , Fu Honggang 
Published: March 2010

AbstractSilver particles with different degrees of aggregation were synthesized through a sodium dodecyl sulfate‐assisted one‐pot reaction in an aqueous medium. The products were characterized by transmission electron microscopy, scanning electron microscopy and UV‐visible spectroscopy. The results showed that the degree of aggregation of the Ag nanoparticles could be tuned by changing the reaction parameters, such as the reaction temperature and time. A possible formation process of the Ag aggregate is proposed on the basis of a series of experimental results. Moreover, the surface‐enhanced Raman scattering (SERS) effect of the Ag aggregates was evaluated by using rhodamine 6G as a Raman probe molecule. It was demonstrated that the SERS enhancement ability is related to the degree of aggregation of Ag particles, and a high SERS signal can be observed by selecting Ag nanoparticles with the proper degree of aggregation as substrates. Moreover, the aggregates showed good reproducibility and stability to SERS from organic molecules. Copyright © 2010 John Wiley & Sons, Ltd.
Kinetics and mechanism of tertiary amine‐catalyzed cleavage of N′‐morpholino‐N‐(2′‐methoxyphenyl)phthalamide: Kinetic evidence for the presence of a reactive intermediate on the reaction path
Authors: Sim Yoke‐Leng , Khan M. Niyaz 
Published: March 2010

AbstractPseudo‐first‐order rate constants (kobs) for tertiary amine (DABCO and Me3N) buffer‐catalyzed cyclization of N′‐morpholino‐N‐(2′‐methoxyphenyl)phthalamide (1) to N‐(2′‐methoxyphenyl)phthalimide (2) reveal saturation (nonlinear) plots of kobs versus [Buf]T (total tertiary amine buffer concentration) at a constant pH. Such plots at different pH have been attributed to the presence of a reactive intermediate (T−) formed by tertiary amine buffer‐catalyzed intramolecular nucleophilic addition of the secondary amide nitrogen to the carbonyl carbon of the tertiary amide group of 1. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 263–272, 2010
Computational studies on the reactions of 3‐butenyl and 3‐butenylperoxy radicals
Authors: Miyoshi Akira 
Published: March 2010

AbstractThe reactions of 3‐butenyl (•CH2CH2CHCH2) radicals—unimolecular decomposition, isomerization, as well as reaction with O2—and the subsequent unimolecular rearrangement reactions of the 3‐butenylperoxy radicals have been investigated and are compared to the analogous reactions of butyl (•CH2CH2CH2CH3) and butylperoxy radicals using transition‐state theory based on the quantum chemical calculations at the CBS‐QB3 level. For alkyl‐analogue processes, the reactions of 3‐butenyl and 3‐butenylperoxy radicals can be well characterized by the decreased and increased bond dissociation energies at the allylic and vinylic sites, respectively. The intramolecular addition reactions of the radical center atoms to the double bonds were found to be important non‐alkyl‐analogue reactions of 3‐butenyl and 3‐butenylperoxy radicals. As a consequence, the thermal decomposition of 3‐butenyl radicals was found to be slower than that of butyl radicals by one order of magnitude at temperature near 1000 K. Intramolecular addition reactions are suggested to be the predominant unimolecular rearrangement processes of 3‐butenylperoxy radicals over the entire temperature range investigated (500–1200 K). The intramolecular addition reactions of the alkenyl peroxy radicals, which have not been included in combustion kinetic models, and their implications for the autoignition of alkenes are discussed. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 273–288, 2010
DFT study of nitroxide radicals: explicit modeling of solvent effects on the structural and electronic characteristics of 4‐amino‐2,2,6,6‐tetramethyl‐piperidine‐N‐oxyl
Authors: Ikryannikova Larissa N. , Ustynyuk Leila Yu. , Tikhonov Alexander N. 
Published: March 2010

AbstractAn explicit DFT modeling of water surroundings on the electron paramagnetic resonance properties of 4‐amino‐2,2,6,6‐tetramethyl‐piperidine‐N‐oxyl (TA) has been performed. A stepwise hydration of TA is accompanied with certain changes in geometrical parameters (bond lengths and angles) and redistribution of partial electric charges in TA. An aqueous cluster of 45 water molecules can be considered as an appropriate model for a complete aqueous shell around TA, although most of the structural and electronic characteristics of TA already converge at about 10 water molecules. Water surroundings induce an increase in electron spin density on the nitrogen atom of the nitroxide fragment due to stabilization of the polar resonance structure > N+•O− at the expense of less polar structure > NO•. The water‐induced rise of the isotropic splitting constant aiso, calculated from the contact term of the hyperfine interaction, comprises Δaiso(ρN2) = 2.2–2.5 G, which is typical of experimental value for TA. There are two contributions to the solvent effect on the aiso(ρN2) value: the redistribution of spin density in the nitroxide fragment (polarity effect) and water‐induced distortions of TA geometry. Microscopic variations in a hydrogen‐bonded water network cause noticeable fluctuations of the splitting constant aiso(ρN2). Calculations of the atomic spin density (σN2) allowed us to compute the splitting constant from the relationship aiso(σN2) = QσN2, where Q = 36.2 G. A practical advantage of using this relationship is that it gives ‘smoothed’ values of the splitting constant, which are sensitive to the environment polarity but remain tolerant to microscopic fluctuations of the hydrogen‐bonded water network around a spin‐label molecule. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical modelling of desiccation cracking
Authors: Amarasiri Aruna L. , Kodikara Jayantha K. , Costa Susanga 
Published: March 2010

AbstractThe ability to model and predict the formation of desiccation cracks is potentially beneficial in many applications such as clay liner design, earth dam construction, and crop science, etc. However, most studies have focused on statistical analysis of crack patterns and qualitative study of contributing factors to crack development rather than prediction. Because it is exceedingly difficult to capture the nonlinear processes during desiccation in analytical modelling, most such models handle crack formation without considering variation of material properties with time, and are unattractive to use in realistic modelling. The data obtained from laboratory experiments on clay soil desiccating in moulds were used as a basis to develop a more refined model of desiccation cracking. In this study, the properties, such as matric suction, stiffness and tensile strength of soil, and base adhesion, could be expressed approximately as functions of moisture content. The initial conditions and the development of suction due to desiccation and the varying material properties were inputted to UDEC, a distinct element code, using its internal programming language FISH. The model was able to capture some essential physical aspects of crack evolution in soil contained in moulds with varying lengths, heights, and materials of construction. Extension of this methodology is potentially beneficial not only for modelling desiccation cracking in clay, but also in other systems with evolving material properties such as concrete structures and road pavements. Copyright © 2010 John Wiley & Sons, Ltd.
Rate effects in dense granular materials: Linear stability analysis and the fall of granular columns
Authors: Lemiale V. , Mühlhaus H.‐B. , Mériaux C. , Moresi L. , Hodkinson L. 
Published: March 2010

AbstractIn this paper, the suitability of rate‐dependent constitutive relationships to model the rheology of granular materials is investigated. In particular, the formation of shear bands as predicted by this approach is studied. First, a rate‐dependent model is investigated in terms of a linear stability analysis. It turns out that at low to moderate strain rates, the orientation of shear bands tends to vary from the so‐called Roscoe and Coulomb solutions towards a unique admissible orientation with an increase of the so‐called inertial number I. This effect is confirmed by numerical simulations of a compression test performed with a particle in cell finite element program. To further assess the validity of continuum approaches for the simulation of dense granular flows, a quasi‐static fall of a granular column is studied numerically and the results are confronted to available experimental data. It is shown that a satisfying agreement is obtained at different aspect ratios and for the two materials investigated in this paper, i.e. sand and glass beads. The results reported in the present paper demonstrate the relevance of continuum approaches in the modelling of dense granular flows. Copyright © 2010 John Wiley & Sons, Ltd.