bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chondrogenic differentiation of murine and human mesenchymal stromal cells in a hyaluronic acid scaffold: Differences in gene expression and cell morphology
Authors: Lisignoli Gina , Cristino Sandra , Piacentini Anna , Zini Nicoletta , Noël Danièle , Jorgensen Christian , Facchini Andrea 
Published: February 2006

AbstractChondrogenesis is a complex process characterized by a sequence of different steps that start with the condensation of the cells, followed by the expression of specific components, such as collagens and proteoglycans. We evaluated in vitro chondrogenic differentiation of C3H10T1/2 murine mesenchymal cells and compared them with human mesenchymal stromal cells (h‐MSCs) in a hyaluronic acid scaffold. We analyzed (from day 0 to day 28) cellular morphology, proliferation, and chondrogenic/osteogenic gene expression at different time points. Our data demonstrate that, during chondrogenic differentiation, murine cells proliferate both in the absence and presence of TGFβ, while h‐MSCs require the presence of this activating factor. Murine cells, even if viable, differentiate on hyaluronan scaffold, maintain a fibroblastic morphology, and form a capsule outside the scaffold. At the mRNA level, murine cells showed a decrease in collagen type I combined with a significant increase in collagen type II (from day 0), and aggrecan (on day 28), as found for h‐MSCs. Immunohistochemical data confirmed that chondrogenic differentiation of murine cells, induced by TGFβ, occurred only in some restricted areas inside the scaffold that were positive to collagen type II, but did not show a cartilage‐like tissue structure, as we had found using h‐MSCs. These data demonstrate that C3H10T1/2 murine cells, widely used as a chondrogenic model, show a different sequence of chondrogenic events in hyaluronic acid scaffold, compared with primary h‐MSCs. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Intra‐ and extracellular reactive oxygen species generated by blue light
Authors: Omata Y. , Lewis J.B. , Rotenberg S. , Lockwood P.E. , Messer R.L.W. , Noda M. , Hsu S.D. , Sano H. , Wataha J.C. 
Published: February 2006

AbstractBlue light from dental photopolymerization devices has significant biological effects on cells. These effects may alter normal cell function of tissues exposed during placement of oral restorations, but recent data suggest that some light‐induced effects may also be therapeutically useful, for example in the treatment of epithelial cancers. Reactive oxygen species (ROS) appear to mediate blue light effects in cells, but the sources of ROS (intra‐ versus extracellular) and their respective roles in the cellular response to blue light are not known. In the current study, we tested the hypothesis that intra‐ and extracellular sources of blue light‐generated ROS synergize to depress mitochondrial function. Normal human epidermal keratinocytes (NHEK) and oral squamous cell carcinoma (OSC2) cells were exposed to blue light (380–500 nm; 5–60 J/cm2) from a dental photopolymerization source (quartz–tungsten–halogen, 550 mW/cm2). Light was applied in cell‐culture media or balanced salt solutions with or without cells present. Intracellular ROS levels were estimated using the dihydrofluorescein diacetate (DFDA) assay; extracellular ROS levels were estimated using the leucocrystal violet assay. Cell response was estimated using the MTT mitochondrial activity assay. Blue light increased intracellular ROS equally in both NHEK and OSC2. Blue light also increased ROS levels in cell‐free MEM or salt solutions, and riboflavin supplements increased ROS formation. Extracellularly applied ROS rapidly (50–400 μM, <1 min) increased intracellular ROS levels, which were higher and longer‐lived in NHEK than OSC2. The type of cell‐culture medium significantly affected the ability of blue light to suppress cellular mitochondrial activity; the greatest suppression was observed in DMEM‐containing or NHEK media. Collectively, the data support our hypothesis that intra‐ and extracellularly generated ROS synergize to affect cellular mitochondrial suppression of tumor cells in response to blue light. However, the identity of blue light targets that mediate these changes remain unclear. These data support additional investigations into the risks of coincident exposure of tissues to blue light during material polymerization of restorative materials, and possible therapeutic benefits. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Configuration distribution and designs of codes in the Johnson scheme
Authors: Etzion Tuvi 
Published: February 2006

AbstractThe main goal of this article is to present several connections between perfect codes in the Johnson scheme and designs, and provide new tools for proving Delsarte conjecture that there are no nontrivial perfect Codes in the Johnson scheme. Three topics will be considered. The first is the configuration distribution which is akin to the weight distribution in the Hamming scheme. We prove that if there exists an e‐perfect code $\cal C$ in the Johnson scheme then there is a formula which connects the number of vectors at distance i from any codeword in various codes isomorphic to $\cal C$. The second topic is the Steiner systems embedded in a perfect code. We prove a lower bound on the number of Steiner systems embedded in a perfect code. The last topic is the strength of a perfect code. We show two new methods for computing the strength of a perfect code and demonstrate them on 1‐perfect codes. We further discuss how to settle Delsarte conjecture. © 2006 Wiley Periodicals, Inc. J Combin Designs 15: 15–34, 2007
D‐optimal designs and group divisible designs
Authors: Tamura Hiroki 
Published: February 2006

AbstractWe obtain new conditions on the existence of a square matrix whose Gram matrix has a block structure with certain properties, including D‐optimal designs of order $n\equiv 3 \pmod 4$, and investigate relations to group divisible designs. We also find a matrix with large determinant for n = 39. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 451–462, 2006
Heterogeneity of the Ca2+ sensitivity of secretion in a pituitary gonadotrope cell line and its modulation by protein kinase C and Ca2+
Authors: Liu Hui‐Sheng , Hu Zhi‐Tao , Zhou Ke‐Ming , Jiu Ya‐Ming , Yang Hua , Wu Zheng‐Xing , Xu Tao 
Published: February 2006

AbstractModulation of the Ca2+ sensitivity and cooperativity of secretion is an important means of regulating neurotransmission and hormone secretion. Employing high‐time resolution measurement of membrane capacitance (Cm) stimulated by step‐like or ramp [Ca2+]i elevation, we have identified the co‐existence of both a high and low Ca2+‐sensitive exocytosis in an immortal pituitary gonadotrope cell line, LβT2. Ramp [Ca2+]i generated by slow uncaging elicited a biphasic Cm response. The first phase of response, which represents a highly Ca2+‐sensitive pool (HCSP) of vesicles, began to secrete at low [Ca2+]i concentration (<1 µM) with low Ca2+ cooperativity. In contrast, the second phase, which represents a lowly Ca2+‐sensitive pool (LCSP) of vesicles, only exocytozed at higher [Ca2+]i (>5 µM) and displayed a steep Ca2+ cooperativity. The co‐existence of vesicle populations with different Ca2+ sensitivities was further confirmed by flash photolysis stimuli. The size of the HCSP was ∼30 fF under resting conditions, but was dramatically increased (∼ threefold) by application of phorbol‐12‐myristate‐13‐acetate (PMA, an activator of protein kinase C). Forskolin (an activator of protein kinase A), however, exerted no significant effect on the size of both HCSP and LCSP. GnRH (gonadotropin releasing hormone) augmented the size of both pools to a larger extent (5‐ and 1.7‐fold increase for HCSP and LCSP, respectively). The heterogeneity of Ca2+ sensitivity from different pools of vesicles and its differential modulation by intracellular signals suggests that LβT2 cells are an ideal model to further unravel the mechanism underlying the modulation of Ca2+‐sensing machineries for exocytosis. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.
Evolved sex differences and occupational segregation
Authors: Browne Kingsley R. 
Published: February 2006

AbstractAverage sex differences in workplace outcomes are often assumed to be products of a malfunctioning labor market that discourages women from nontraditional occupations and a biased educational system that leaves women inadequately prepared for scientific and technical work. Rather than being a product purely of discriminatory demand, however, many sex differences in occupational distribution are at least partially a result of an imbalance in supply. Sex differences in both temperament and cognitive ability, which are products of our evolutionary history, predispose men and women toward different occupational behavior. The tendency of men to predominate in fields imposing high quantitative demands, high physical risk, and low social demands, and the tendency of women to be drawn to less quantitatively demanding fields, safer jobs, and jobs with a higher social content are, at least in part, artifacts of an evolutionary history that has left the human species with a sexually dimorphic mind. These differences are proximately mediated by sex hormones. Copyright © 2006 John Wiley & Sons, Ltd.
Hatching a plan: Developing leadership talent in emerging markets
Authors: Richman Hal , Wiggenhorn A. William 
Published: February 2006

AbstractEmerging markets, which have a strong economic growth trajectory and market opportunity, are of great interest to large multinational corporations and other organizations with an international presence. But there is a lot of leadership talent waiting to be developed in these markets, and a lot of risk if this development doesn't occur. Here's a look at some actions that organizations operating in emerging markets can take to strengthen their leadership pools.
Multiple Morphologies and Their Transformation of a Polystyrene‐block‐poly(4‐vinylpyridine) Block Copolymer
Authors: Liu Libin , Gao Xiang , Cong Yong , Li Binyao , Han Yanchun 
Published: February 2006

AbstractSummary: We report the multiple morphologies and their transformation of polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) in low‐alkanol solvents. In order to improve the solubility of polystyrene block in alcohol solvents, the solution of block copolymer sample was treated at a higher temperature, and then the influence of rate of decreasing temperature on multiple morphologies (including spheres, rods, vesicles, porous vesicles, large compound vesicles, and large compound micelles) was observed. The transformation of spheres to rods, to tyre‐shaped large compound micelles, and to sphere‐shaped large compound micelles was also realized. The formation mechanisms of the multiple morphologies and their transformation are discussed briefly.Aggregates of PS‐P4VP formed in butanol by quenching from 110 °C to room temperature.magnified imageAggregates of PS‐P4VP formed in butanol by quenching from 110 °C to room temperature.
Hemicellulose Composition in the Outer Cell Wall Layers of Paper Grade and Dissolving Pulp
Authors: Freese Maren , Schmidt Ingeborg , Fischer Klaus 
Published: February 2006

AbstractThe hemicellulose content of pulp is dependent on different factors, such as the wood species, the conditions with cooking and bleaching harmonised with the application.In addition to the hemicellulose content, a special interest for the valuation of pulp and the decision of arrangements of the production process is the hemicellulose distribution across the cell wall layers and the influence of several process stages on the hemicellulose distribution across the cell wall layers.The investigations were carried out on dissolving pulp and paper grade pulp.For paper grade pulp, the influence of separate bleaching steps and several bleaching sequences on the distribution of hemicellulose across the cell wall were investigated.Regarding the selected dissolving pulps which were produced according to an acid bisulphite process and a pre‐hydrolysis sulphate process the influence of the cooking process on the hemicellulose distribution across the cell wall layers was of a special interest.
Carboxymethyl Xylan ‐ Control of Properties by Synthesis
Authors: Petzold Katrin , Schwikal Katrin , Günther Wolfgang , Heinze Thomas 
Published: February 2006

AbstractThe hemicellulose xylan is a polysaccharide that occurs in nature in enormous amount in various one year‐ and perennial plants having different structures and molecular masses. Versatile ways to generate bio‐based functional polymers result from the chemical modification of this biopolymer. In our research, xylans from various resources like birch‐, beech‐, and eucalyptus wood and from oat husk, rye bran, and corn cob were used to investigate the important method of carboxymethylation in detail. Different activation procedures were elaborated to synthesize carboxymethyl xylan. One step reactions lead to products with a degree of substitution (DS) from 0.13 to 1.22 in dependence on the molar ratio of anhydroxylose unit (AXU) to reagent. Two step syntheses yielded DS values up to 1.65. Carboxymethyl xylans are water soluble at a DS of 0.3. The solutions have different clearness depending on the provenience. NMR spectroscopy and HPL chromatography were applied to characterize the carboxymethyl xylans in detail.
Studies on the Film Formation of Polysaccharide Based Furan‐2‐Carboxylic Acid Esters
Authors: Hesse Stephanie , Liebert Tim , Heinze Thomas 
Published: February 2006

AbstractFuran‐2‐carboxylic acid esters of xylan, cellulose, curdlan, dextran, and starch were synthesized and studied regarding their film formation abilities. The polysaccharide esters were utilized to prepare films of different appearance. To investigate supermolecular structures of the biopolymer derivatives, atomic force‐ and scanning electron microscopy were applied. The surface roughness and the macro‐pore size and ‐distribution of the polysaccharide ester films were characterized. Starch furan‐2‐carboxylic acid ester (starch furoate) did not show film formation. In contrast, dextran furoates are very well suitable for the surface coating of inorganic compounds while the xylan‐, cellulose‐, and curdlan derivatives yield self‐supporting films with different surface characteristics.
Xylans from Oat Spelts and Birch Kraft Pulp
Authors: Puls Jürgen , Schröder Nils , Stein Armin , Janzon Ron , Saake Bodo 
Published: February 2006

AbstractTwo different approaches for the isolation of xylan from hemicellulose‐rich sources have been investigated: Alkaline extraction from roller‐mill pretreated oat spelts and Nitren extraction of birch kraft pulp. For xylan recovery from oat spelts the experiments included extraction with 5% NaOH at 90 °C, followed by precipitation in methanol or 2‐propanol without neutralisation in order to facilitate NaOH recovery. A subsequent peroxide bleaching yielded a product of approximately 90% ISO brightness. The work on Nitren extraction of birch kraft pulp included the optimisation of the extraction process with regard to the Nitren charge. Nitren was much more specific in xylan extraction compared to Cuen, and up to 90% of the xylan content of the birch kraft pulp could be removed. It turned out that dried pulps were superior for this process compared to never‐dried pulps, since substantial cellulose proportions in never‐dried pulps were also mobilised by Nitren treatment. The properties of the recovered xylans from both processes were compared with regard to molar mass and substitution. It could be demonstrated that more or less intact arabinoxylans with molar masses of 30,000 g/mol could be obtained from oat spelts. The arabinoxylans contained 8–10 mol‐% arabinofuranose and 2 mol‐% 4‐O‐methylglucuronic acid substituents. Nitren extraction of a birch kraft pulp yielded xylans of 9,400 and 11,200 g/mol. Only traces of 4‐O‐methyl‐glucuronic‐ and hexenuronic acid substituents could be found.
Isolation, Synthesis and Derivatization of Xylodextrins
Authors: Abad‐Romero Beatriz , Haltrich Dietmar , Potthast Antje , Rosenau Thomas , Sixta Herbert , Kosma Paul 
Published: February 2006

AbstractA series of xylodextrins has been produced by enzymatic or hydrothermal degradation of industrial xylans. For further synthetic use, the oligomers were converted into per‐O‐acetylated xylooligomers which were separated by silica gel chromatography to furnish preparative amounts of xylobiose up to xylopentaose. In a model reaction, selective anomeric deacetylation and treatment with trichloroacetonitrile furnished a xylobiosyl donor, which was converted into the β‐methyl glycoside. In addition, methyl β‐D‐xylopyranoside was transformed into a suitable glycosyl acceptor via tosylation followed by a double displacement reaction at O‐4, allowing for further chain elongation and modification at the reducing xylopyranosyl unit.
Xylo‐Oligosaccharide (XOS) Formation through Hydrothermolysis of Xylan Derived from Viscose Process
Authors: Griebl Alexandra , Lange Thomas , Weber Hedda , Milacher Walter , Sixta Herbert 
Published: February 2006

AbstractXylo‐oligosaccharides (XOS) have gained growing interest during the past decade owing to their beneficial influence on health. At the same time, a trend to a more effective utilization of biomass and biomass degradation products can be observed. As a consequence, also the steeping‐lye of the viscose process is discussed as a potential source of new products based on xylans, xylooligosaccharides, xylose, and different xylose degradation products, thus being a driving force for the development of appropriate production processes. Therefore, xylan isolated from the steeping‐lye was subjected to hydrothermal degradation for production of xylo‐oligosaccharides (XOS). The experiments were carried out at 120, 150, and 180 °C, respectively. This hydrothermal treatment led to a soluble fraction, consisting of neutral and acidic XOS, and an insoluble residue predominantly made up of highly crystalline cellulose. A mass balance was established to calculate the activation energy for hydrothermal xylan degradation from weight loss kinetics. The degree of polymerization (DP) of the neutral product fraction could be influenced in a wide range by the reaction conditions applied. Acidic XOS were further characterized using mass spectrometry (MS). A 4‐O‐methylglucuronic acid residue α‐(1,3)‐linked to the xylose backbone was detected as a new structural element in alkaline degradation products derived from beech wood xylan.
Kinesthesia is impaired in focal dystonia
Authors: Putzki Norman , Stude Philipp , Konczak Jürgen , Graf Karoline , Diener Hans‐Christoph , Maschke Matthias 
Published: February 2006

AbstractParkinson's disease (PD) and focal dystonia (FD) are both predominantly characterized by motor symptoms. Also, recent research has shown that sensory processing is impaired in both movement disorders. FD is characterized by involuntary movements and abnormal limb postures; thus, abnormal kinesthesia could be involved in the pathogenesis. We examined passive index finger movements in patients with FD (n = 12) and PD (n = 11) and in age‐matched healthy controls (n = 13). Compared to healthy controls, patients with PD and FD were significantly impaired in the correct detection of the movement direction. The perceptual thresholds for 75% correct responses of movement direction were 0.21 degrees for FD and 0.28 degrees for PD patients compared to 0.13 degrees in control subjects. Subjects with PD and FD were also significantly impaired when they had to judge consecutive amplitudes. Results of the present study point to impaired kinesthesia in FD. Defective sensory processing could be involved in the pathophysiology of the disease and may influence dystonic contractions. © 2006 Movement Disorder Society
Congenital disorder of glycosylation type Ia presenting as early‐onset cerebellar ataxia in an adult
Authors: Schoffer Kerrie L. , O'Sullivan John D. , McGill Jim 
Published: February 2006

AbstractCongenital disorders of glycosylation (CDG) are a recently described, underrecognized group of syndromes characterized biochemically by abnormal glycosylation of serum and cellular glycoproteins. We report a previously undiagnosed adult male who presented with early‐onset cerebellar ataxia in the context of mental impairment, peripheral neuropathy, retinopathy, body dysmorphism, cardiomyopathy, and hypogonadism. Newly available screening and genetic testing confirmed the diagnosis as CDG type Ia. This case emphasizes that CDG should be considered as a differential diagnosis for adults with early‐onset cerebellar ataxia, particularly in those persons with the aforementioned features, and that undiagnosed cases of childhood ataxia may require reassessment now that testing is available. © 2006 Movement Disorder Society
Structural MRI of carotid artery atherosclerotic lesion burden and characterization of hemispheric cerebral blood flow before and after carotid endarterectomy
Authors: Jones C. E. , Wolf R. L. , Detre J. A. , Das B. , Saha P. K. , Wang J. , Zhang Y. , Song H. K. , Wright A. C. , Mohler E. M. , Fairman R. M. , Zager E. L. , Velazquez O. C. , Golden M. A. , Carpenter J. P. , Wehrli F. W. 
Published: February 2006

AbstractCollateral circulation plays a major role in maintaining cerebral blood flow (CBF) in patients with internal carotid artery (ICA) stenosis. CBF can remain normal despite severe ICA stenosis, making the benefit of carotid endarterectomy (CEA) or stenting difficult to assess. Before and after surgery, we assessed CBF supplied through the ipsilateral (stenotic) or contralateral ICA individually with a novel hemisphere‐selective arterial spin‐labeling (ASL) perfusion MR technique. We further explored the relationship between CBF and ICA obstruction ratio (OR) acquired with a multislice black‐blood imaging sequence. For patients with unilateral ICA stenosis (n = 19), conventional bilateral labeling did not reveal interhemispheric differences. With unilateral labeling, CBF in the middle cerebral artery (MCA) territory on the surgical side from the ipsilateral supply (53.7 ± 3.3 ml/100 g/min) was lower than CBF in the contralateral MCA territory from the contralateral supply (58.5 ± 2.7 ml/100 g/min), although not statistically significant (p = 0.09). The ipsilateral MCA territory received significant (p = 0.02) contralateral supply (7.0 ± 2.7 ml/100 g/min), while ipsilateral supply to the contralateral side was not reciprocated. After surgery (n = 11), ipsilateral supply to the MCA territory increased from 57.3 ± 5.7 to 67.3 ± 5.4 ml/100 g/min (p = 0.03), and contralateral supply to the ipsilateral MCA territory decreased. The best predictor of increased CBF on the side of surgery was normalized presurgical ipsilateral supply (r2 = 0.62, p = 0.004). OR was less predictive of change, although the change in normalized contralateral supply was negatively correlated with ORexcess (=ORipsilateral − ORcontralateral) (r2 = 0.58, p = 0.006). The results demonstrate the effect of carotid artery stenosis on blood supply to the cerebral hemispheres, as well as the relative role of collateral pathways before surgery and redistribution of blood flow through these pathways after surgery. Unilateral ASL may better predict hemodynamic surgical outcome (measured by improved perfusion) than ICA OR. Copyright © 2006 John Wiley & Sons, Ltd.