bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new min‐cut problem with application to electric power network partitioning
Authors: Sen Arunabha , Ghosh Pavel , Vittal Vijay , Yang Bo 
Published: March 2008

AbstractThe problem of partitioning a graph into two or more subgraphs that satisfies certain conditions is encountered in many different domains. Accordingly, graph partitioning problem has been studied extensively in the last 50 years. The most celebrated result among this class of problems is the max flow = min cut theorem due to Ford and Fulkerson. Utilizing the modifications suggested by Edmonds and Karp, it is well known that the minimum capacity cut in the directed graph with edge weights can be computed in polynomial time. If the partition divides the node setVinto subsetsV1andV2, whereV1contains one of the specified nodessandV2contains the other specified nodet, the capacity of a cut is defined as the sum of the edge weights going fromV1toV2. In electrical power distribution networks, a slow‐coherency‐based islanding strategy is used as a prevention against the cascading failures. In this paper, we concentrate on the graph partition problems which are encountered in electric power distribution networks. In this environment, two different definitions of capacity of a cut are used. In the first definition, capacity of a cut is taken to be the difference of the edge weights going fromV1toV2and fromV2toV1. In the second definition, the capacity of a cut is taken to be the maximum of sum of the edge weights going fromV1toV2and fromV2toV1. Surprisingly, with slight change of the definition of the capacity of a cut, the computational complexity of the problem changes significantly. In this paper, we show that with the new definitions of the capacity of a cut, the minimum cut computation problem becomes NP‐complete. We provide an optimal solution to the problems using mathematical programming techniques. In addition, we also provide heuristic solutions and compare the performance with that of the optimal solution. Copyright © 2008 John Wiley & Sons, Ltd.
Influences of climate, terrain and land cover on stream salinity in southeastern Australia, and implications for management through reforestation
Authors: van Dijk A. I. J. M. , Gilfedder M. , Austin J. 
Published: March 2008

AbstractReforestation of cleared land has the potential to reduce groundwater recharge, salt mobilization and streamflow. Stream salinity change is the net result of changes in stream salt load and streamflow. The net effect of these changes varies spatially as a function of climate, terrain and land cover. Successful natural resource management requires methods to map the spatial variability of reforestation impacts. We investigated salinity data from 2000 bores and streamflow and salinity measurements from 27 catchments in the Goulburn–Broken region in southeast Australia to assess the main factors determining stream salinity and opportunities for management through reforestation. For groundwater systems of similar geology, relationships were found between average annual rainfall and groundwater salinity and between groundwater salinity and low‐flow salinity. Despite its simplicity, we found that the steady‐state component of a simple conceptual coupled water–salt mass balance model (BC2C) adequately explained the spatial variation in streamflow and salinity. The model results suggest the efficiency of afforestation to reduce stream salinity could be increased by more than an order of magnitude through spatial planning. However, appreciable reductions in stream salinity in large rivers through land cover change alone would still require reforestation on an unprecedented scale. Copyright © 2008 John Wiley & Sons, Ltd.
p53 reaction to apoptosis induced by hydroxyapatite nanoparticles in rat macrophages
Authors: Sun Jiao , Ding Tingting 
Published: March 2008

AbstractThe effects and mechanism of hydroxyapatite (HAP) nanoparticles (NPs) on the induction of cytotoxicity and apoptosis in rat macrophages was evaluated by testing the antiproliferative effect of HAP NPs with agar overlay and direct contact methods. The apoptotic phenotype of the macrophages was observed by transmission electron microscopy (TEM), and the variation of transcription and expression of a cell apoptosis related gene (p53) was determined by semiquantitative RT‐PCR and western blotting. The results showed that a dose‐dependent proliferative inhibition of macrophages was induced by HAP NPs (30–80 nm) at concentrations between 20 and 200 μg/mL. The characteristic morphological changes of apoptosis were observed in macrophages after treatment with HAP NPs for 24 h. Furthermore, p53 mRNA levels significantly increased when macrophages were incubated with 200 μg/mL HAP NPs (p < 0.01). Western blot analysis showed that 100 μg/mL HAP NPs upregulated p53. The conclusion is that HAP NPs can induce p53 expression through phosphorylation, which promotes downstream genes and finally results in cell apoptosis. Moreover, p53 may be one of the ideal indictors to evaluate the biological safety of ceramic nanoparticles. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Surface‐initiated atom‐transfer radical polymerization of 3‐O‐methacryloyl‐1,2:5,6‐di‐ O‐isopropylidene‐α‐ D‐glucofuranoside onto gold surface
Authors: Yoon Kuk Ro , Ramaraj B. , Lee Seungho , Yu Jong‐Sung , Choi Insung S. 
Published: March 2008

AbstractA sugar‐containing polymer was grown on gold surface by surface‐initiated atom‐transfer radical polymerization (SI‐ATRP) of methacrylate monomer, 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranoside (MAIpGIc), using 1,4,8,11‐tetraaza‐1,4,8,11‐tetramethylcyclotetradecane (Me4Cyclam) as ligand, 2‐bromopropionyl moiety attached on the gold surface as initiator, and Copper(I) bromide as catalyst, respectively, in tetrahydrofuran (THF) medium. The resultant sugar film was characterized by polarized infrared external reflectance spectroscopy (PIERS), X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), field emission scanning electron microscopy (FE‐SEM), ellipsometry, and contact angle goniometry. The IR peaks characteristics of poly(3‐O‐methacryloyl‐α,β‐D‐glucopyranoside) (PMAGlc), broad OH stretch at ∼3400 cm−1, and CO ester stretch at ∼1748 cm−1 observed in PIERS spectra demonstrate the formation of PMAGlc on the gold surface. The AFM and SEM images show the polymer growth away from the gold surface without visible domain boundaries, and it further confirms the formation of sugar coating. The method described in the article would be beneficial in many areas, such as pathogen detection and biosensors, considering the biological importance of carbohydrate polymers. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Histopathology of the three implanted degradable biopolymers in rabbit eye
Authors: Rönkkö Seppo , Rekonen Petri , Sihvola Roope , Kaarniranta Kai , Puustjärvi Tuomo , Teräsvirta Markku , Uusitalo Hannu 
Published: March 2008

AbstractNew straightforward applications of new biopolymers are needed in glaucoma surgery. The aim of this study was to compare biocompatibility of three biomaterials in rabbit eyes after deep sclerectomy; a collagen implant (AquaFlow™) represented the “gold standard”. A blend of 85:15 poly(L‐lactide‐co‐glycolide) and 70:30 poly(L‐lactide‐co‐1,3‐trimethylene carbonate) copolymers in a molar ratio of 70:30 (Bio‐1 = Inion GTR™ membrane) and poly(DL‐lactide‐co‐glycolide with molar compositions of 50:50 (Bio‐2) and 85:15 (Bio‐3) were inserted into rabbits eyes. Bio‐1, Bio‐2 or Bio‐3 caused very mild eye irritation or tissue response which was comparable to that of the collagen implant. The biodegradation time of Bio‐1, Bio‐2, and Bio‐3 implants was over one year, 3 months and 6 months, respectively. Implant mapping by Fourier transform infrared (FTIR) microscopy revealed a heterogeneous distribution of degradation products throughout Bio‐1, Bio‐2, and Bio‐3. All implants were surrounded by a very fine tissue capsule which was not visible after total degradation of the implants. The FTIR spectrum of tissue capsule around Bio‐1 was almost identical to that around Bio‐2 whereas significant differences were observed in the spectrum of the tissue capsule around Bio‐3. Despite some differences in tissue response, all tested implants represent biologically acceptable materials for drainage devices in glaucoma surgery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Nanophase separation of polymers exposed to simulated bonding conditions
Authors: Ye Qiang , Wang Yong , Spencer Paulette 
Published: March 2008

AbstractUnder in vivo conditions, there is little control over the amount of water left on the tooth during dentin bonding. As a result, it is possible to leave the dentin surface so wet that the adhesive actually undergoes physical separation into hydrophobic‐ and hydrophilic‐rich phases. Using tapping mode atomic force microscopy/PhaseImaging technique, nanosized phases with worm‐like features were found on the surface of model HEMA/BisGMA dentin adhesives cured in the presence of varying concentrations of water. The phase contrast became evident with the increase of water concentration in the initial adhesive formulation and varied with the ratio of hydrophilic/hydrophobic composition. Oversaturated water droplets of variable sizes may accumulate as micro‐voids within the hydrophilic and hydrophobic polymer phases. The phase domains were also identified following ethanol‐etching in combination with SEM/AFM techniques. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The role of hydroxyapatite as solid signal on performance of PCL porous scaffolds for bone tissue regeneration
Authors: Guarino Vincenzo , Causa Filippo , Netti Paolo A. , Ciapetti Gabriela , Pagani Stefania , Martini Desiree , Baldini Nicola , Ambrosio Luigi 
Published: March 2008

AbstractHighly porous composites made up of biodegradable poly‐ε‐caprolactone (PCL) and stoichiometric hydroxyapatite (HA) particles have been developed as substrate for bone‐tissue regeneration. The processing technique consists of phase inversion and particulate (salt crystals) leaching. Three different HA contents (13, 20 and 26 vol %) in PCL‐based composite were considered in this study. Pore microstructure with fully interconnected network and pore sizes ranging around a few hundred of μm (macroporosity) was obtained as a result of salt particles removal by leaching process. Several microns (microporosity) porosity was also created through phase inversion of polymer solution. Total porosity up to 95% was achieved. Human marrow stromal cells (MSC) were seeded onto porous PCL‐based composites for 1–5 weeks and cultured in osteogenic medium. MSC were able to adhere and grow on PCL‐based substrates with a plateau at 3–4 weeks. However, the small effect of bioactive signals on the biological response evaluated in MSC cell culture suggests a prior role of topography on the biological response. Importantly, the presence of HA as a bioactive solid signal determines an increase of mechanical properties. On the overall, the results indicated that porous PCL‐based composites are potential candidate for bone substitution with beneficial influence on structural characteristics by solid signal addition. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Selection of a practical assay for the determination of the entire range of acetyl content in chitin and chitosan: UV spectrophotometry with phosphoric acid as solvent
Authors: Hein San , Ng Chuen‐How , Stevens Willem F. , Wang Kean 
Published: March 2008

AbstractThe rapidly expanding use of chitomaterials in biomedical applications demands accurate and precise analytical methods to determine physico‐chemical characteristics, especially the acetyl content of the sample. The analytical methods available for the determination of the acetyl content of the biomaterials are quite different in efficiency, accuracy and precision. Out of 22 analytical methods reviewed, XRD, DSC, FTIR (KBr pellet), solid state13C CP/MAS NMR, and acid hydrolysis‐HPLC and the spectrophotometry assay using phosphoric acid as solvent (PUV) were selected in this study. The validity and applicability of these methods were investigated with a wide range of chitin and chitosan samples varying acetyl content, preparation methods, and sources. The XRD, DSC, and FTIR (KBr pellet) methods showed poor accuracy with the samples of diverse preparations and sources. The PUV method was modified and accuracy of the method was examined against absolute methods: solid state13C CP/MAS NMR and acid hydrolysis‐HPLC methods. The correlations between these three methods were >0.9. Therefore, the PUV method was selected as the most generally acceptable method based on its accuracy, reliability, simplicity, and instrument availability. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Effects of corticosterone deficiency and its replacement on leydig cell steroidogenesis
Authors: Parthasarathy C. , Balasubramanian K. 
Published: March 2008

AbstractClinical and experimental studies have shown the adverse effects of glucocorticoid deficiency/metyrapone treatment on testicular Leydig cell testosterone production. However, molecular mechanisms that underlie the effects of glucocorticoid deficiency on Leydig cell steroidogenesis are not yet determined. Therefore, the present study was designed to assess the mechanism of this phenomenon. Following metyrapone‐induced corticosterone deficiency, serum testosterone, and Leydig cell 14C‐glucose oxidation were decreased. StAR mRNA and protein levels were significantly increased in Leydig cells of corticosterone‐deficient animals. mRNA levels and the specific activities of P450scc and 17β‐HSD were decreased by corticosterone deficiency, whereas the activity and mRNA of 3β‐HSD were increased. Simultaneous administration of corticosterone prevented its deficiency‐induced changes in Leydig cells. Our results show that metyrapone‐induced corticosterone deficiency impairs Leydig cell testosterone production by decreasing the activities of steroidogenic enzymes and their mRNA expression and glucose oxidation. J. Cell. Biochem. 104: 1671–1683, 2008. © 2008 Wiley‐Liss, Inc.
TGF‐β inhibits prolactin‐induced expression of β‐casein by a Smad3‐dependent mechanism
Authors: Wu Wen‐Jun , Lee Chin‐Feng , Hsin Chung‐Han , Du Jyun‐Yi , Hsu Tsai‐Ching , Lin Ting‐Hui , Yao Tsung‐You , Huang Cheng‐Hsieh , Lee Yi‐Ju 
Published: March 2008

AbstractTransforming growth factor‐β (TGF‐β) is a multifunctional growth factor, affecting cell proliferation, apoptosis, and extracellular matrix homeostasis. It also plays critical roles in mammary gland development, one of which involves inhibition of the expression of milk proteins, such as β‐casein, during pregnancy. Here we further explore the underlying signaling mechanism for it. Our results show that TGF‐β suppresses prolactin‐induced expression of β‐casein mRNA and protein in primary mouse mammary epithelial cells, but its effect on protein expression is more evident. We also find out that this inhibition is not due to the effect of TGF‐β on cell apoptosis. Furthermore, inhibition of TGF‐β type I receptor kinase activity by a pharmacological inhibitor SB431542 or overexpression of dominant negative Smad3 substantially restores β‐casein expression. By contrast, inhibition of p38 and Erk that are known to be activated by TGF‐β does not alleviate the inhibitory effect of TGF‐β. These results are consistent with our other observation that Smad but not MAPK pathway is activated by TGF‐β in mammary epithelial cells. Lastly, we show that prolactin‐induced tyrosine phosphorylation of Jak2 and Stat5 as well as serine/threonine phosphorylation of p70S6K and S6 ribosomal protein are downregulated by TGF‐β, although the former event requires considerably long exposure to TGF‐β. We speculate that these events might be involved in repressing transcription and translation of β‐casein gene, respectively. Taken together, our results demonstrate that TGF‐β abrogates prolactin‐stimulated β‐casein gene expression in mammary epithelial cells through, at least in part, a Smad3‐dependent mechanism. J. Cell. Biochem. 104: 1647–1659, 2008. © 2008 Wiley‐Liss, Inc.
Timing of Doppler examination for the detection of arteriovenous fistula after percutaneous renal biopsy
Authors: Yang Chih‐Yu , Lai Ming‐Yu , Lu Cheng‐Lang , Tseng Hsiuo‐Shan , Chiou Hong‐Jen , Yang, Wu‐Chang , Ng Yee‐Yung 
Published: March 2008

AbstractPercutaneous renal biopsy is frequently performed, and postbiopsy arteriovenous fistula (AVF) formation is not uncommon. In most cases, it is asymptomatic and remains undiagnosed, because Doppler examination is not performed routinely. We describe 2 cases of postbiopsy AVF of the kidney that were detected 61 and 17 months after renal biopsy, respectively. The subsequent superselective transcatheter arterial embolization was successful in both cases. An undetected AVF of the kidney can progress and lead to serious consequences. A follow‐up Doppler examination of the kidney soon after renal biopsy and 6 months later is recommended for early detection of nonresolving AVFs to prevent further complications. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
ER stress is involved in Aβ‐induced GSK‐3β activation and tau phosphorylation
Authors: Resende Rosa , Ferreiro Elisabete , Pereira Cláudia , Oliveira Catarina Resende 
Published: March 2008

AbstractIntracellular neurofibrillary tangles, one of the characteristic hallmarks of Alzheimer's disease (AD), are mainly composed of hyperphosphorylated tau. The abnormal tau phosphorylation seems to be related to altered activity of kinases such as glycogen synthase kinase‐3β (GSK‐3β). Tau pathology is thought to be a later event during the progression of the disease, and it seems to occur as a consequence of amyloid‐beta (Aβ) peptide accumulation. The aim of this work was to investigate whether soluble Aβ1–42, particularly oligomers that correspond to the neurotoxic species involved early in the development of AD, triggers tau phosphorylation by a mechanism involving activation of tau‐kinase GSK‐3β. Several studies suggest that GSK‐3β plays a central role in signaling the downstream effects of endoplasmic reticulum (ER) stress. Therefore, the involvement of ER Ca2+ release in GSK‐3β activation and tau phosphorylation induced by Aβ1–42 oligomers was evaluated using dantrolene, an inhibitor of Ca2+ release through channels associated with ER ryanodine receptors. We observed that Aβ1–42 oligomers increase tau phosphorylation and compromises cell survival through a mechanism mediated by GSK‐3β activation. We also demonstrated that oligomeric Aβ1–42 induces ER stress and that ER Ca2+ release is involved in oligomer‐induced GSK‐3β activation and tau phosphorylation. This work suggests that GSK‐3β can be a promising target for therapeutic intervention in AD. © 2008 Wiley‐Liss, Inc.
Retrograde Wallerian degeneration of cranial corticospinal tracts in cervical spinal cord injury patients using diffusion tensor imaging
Authors: Guleria Saurabh , Gupta Rakesh K. , Saksena Sona , Chandra Anil , Srivastava R.N. , Husain Mazhar , Rathore Ramkishore , Narayana Ponnada A. 
Published: March 2008

AbstractDiffusion tensor imaging (DTI) has the potential to reveal disruption of white matter microstructure in chronically injured spinal cords. We quantified fractional anisotropy (FA) and mean diffusivity (MD) to demonstrate retrograde Wallerian degeneration (WD) of cranial corticospinal tract (CST) in cervical spinal cord injury (SCI). Twenty‐two patients with complete cervical SCI in the chronic stage were studied with DTI along with 13 healthy controls. Mean FA and MD values were computed for midbrain, pons, medulla, posterior limb of internal capsule, and corona radiata. Significant reduction in the mean FA and increase in MD was observed in the cranial CST in patients with SCI compared with controls, suggesting retrograde WD. Statistically significant inverse FA and MD changes were noted in corona radiata, indicating some restoration of spared white matter tracts. Temporal changes in the DTI metrics suggest progressing degeneration in different regions of CST. These spatiotemporal changes in DTI metrics suggest continued WD in injured fibers along with simultaneous reorganization of spared white matter fibers, which may contribute to changing neurological status in chronic SCI patients. © 2008 Wiley‐Liss, Inc.
Effect of mother corm dimension and sowing time on stigma yield, daughter corms and qualitative aspects of saffron (Crocus sativus L.) in a Mediterranean environment
Authors: Gresta F. , Lombardo G. M. , Siracusa L. , Ruberto G. 
Published: March 2008

AbstractBACKGROUND: Saffron is one of the most appreciated and expensive spices known and has been used from the oldest times as a dye for fabrics, a condiment to enrich food and for medicinal purposes. The aim of this study was to evaluate the effect of crop management methods on the quantitative and qualitative characteristics of the spice in southern Italy. Two sowing times (end of July and end of August) and two corm dimensions (4 and 3 cm horizontal diameter) were evaluated.RESULTS: Flowering period and duration were not influenced by the studied factors, while early sowing time and greater corm dimension resulted in a greater number of flowers per m2, increased stigma yield and a greater total yield of replacement corms. Early sowing time also showed a significant positive influence on stigma quality measured as apocarotenoid content according to ISO guidelines.CONCLUSION: The results show that, in a Mediterranean environment, appropriate crop techniques and selection of corms can result in economic levels of production and improve the quantitative and qualitative characteristics of saffron. In fact, according to their apocarotenoid contents, samples from the early (July) and late (August) sowing times belonged to the first and second ISO categories respectively. Copyright © 2008 Society of Chemical Industry
Impact of goat milk powdered formulations on mineral absorption, peak bone mass and bone loss due to ovariectomy in rats
Authors: Kruger Marlena C , Chua Wei‐Hang , Darragh Alison , Booth Chris L , Prosser Colin , Lowry Dianne 
Published: March 2008

AbstractBACKGROUND: Goat milk is recognised as nutritious, with benefits to growth and skeletal development. The initial aim of this study was to investigate the effect of three different goat milk formulae—a whole milk, a skim milk and a goat milk growing‐up formula fortified with pre‐ and probiotics (Formula 1)—on mineral absorption and retention in rats. The effect of long‐term intake of the fortified formula diet on peak bone mass and post‐ovariectomy bone loss in rats was then investigated in a follow‐up study and was assessed by bone density dual‐energy X‐ray absorptiometry and biomechanical testing of bone ex vivo.RESULTS: Goat whole milk and fortified milk formulations improved calcium and phosphorus absorption and retention. Body composition analysis showed that rats fed the fortified diet had higher body calcium and phosphorus content. The fortified diet was then tested in a long‐term feeding trial. Rats fed the fortified diet from weaning had a higher peak bone mass than rats fed a soy protein control diet. Bone mineral content (BMC) and density (BMD) of the lumbar spine were higher in rats fed the fortified diet. After ovariectomy, all rats lost bone mass, but rats fed the fortified diet maintained significantly higher BMD and BMC values throughout the trial, though still lower than those of non‐ovariectomised control rats. The fortified diet increased bone strength.CONCLUSION: Goat milk specific nutrients supported by pre‐ and probiotics in Formula 1 may improve mineral status during growth and support attainment of peak bone mass. Copyright © 2008 Society of Chemical Industry