bluuebunny/crossref_metadata_2025 huggingface dataset:
The WNT receptor FZD7 contributes to self-renewal signaling of human embryonic stem cells
Authors: Melchior Kai , Weiß Jonathan , Zaehres Holm , Kim Yong-mi , Lutzko Carolyn , Roosta Neda , Hescheler Jürgen , Müschen Markus
Published: August 2008

A number of recent studies identified nuclear factors that together have the unique ability to induce pluripotency in differentiated cell types. However, little is known about the factors that are needed to maintain human embryonic stem (ES) cells in an undifferentiated state. In a search for such requirements, we performed a comprehensive meta-analysis of publicly available SAGE and microarray data. The rationale for this analysis was to identify genes that are exclusively expressed in human ES cell lines compared to 30 differentiated tissue types. The WNT receptor FZD7 was found among the genes with an ES cell-specific expression profile in both SAGE and microarray analyses. Subsequent validation by quantitative RT-PCR and flow cytometry confirmed that FZD7 mRNA levels in human ES cells are up to 200-fold higher compared to differentiated cell types. ShRNA-mediated knockdown of FZD7 in human ES cells induced dramatic changes in the morphology of ES cell colonies, perturbation of expression levels of germ layer-specific marker genes, and a rapid loss of expression of the ES cell-specific transcription factor OCT4. These findings identify the WNT receptor FZD7 as a novel ES cell-specific surface antigen with a likely important role in the maintenance of ES cell self-renewal capacity.
Treatment of trace organics in membrane concentrates I: pesticide elimination
Authors: Bozkaya-Schrotter B. , Daines C. , Lescourret A.-S. , Bignon A. , Breant P. , Schrotter J. C.
Published: August 2008

The objective of this study was to eliminate organic micropollutants in the membrane system concentrates, which is produced by drinking water production plants, in order to protect existing water resources. This work is divided into two parts, pesticide elimination (I) and natural organic matter removal (II) in membrane system concentrates. Seven commonly detected pesticides in French surface waters, i.e. atrazine, sulcotrione, bentazone, isoproturon, diuron, glyphosate and acetochlore, were selected as the model micropollutants. Removal/degradation of these pesticides was studied by testing conventional processes employed for potable water production, i.e. adsorption, oxidation by ozone and clarification. Only partial removal of these pesticides was achieved with conventional processes. Removal of nonpolar pesticides was obtained by adsorption and rapid degradation of most of the pesticides was observed with low ozone dosages, except for atrazine and its metabolites. On the other hand, only the phosphonate-based pesticides were removed by clarification. By combining these processes, however, almost complete removal of the selected pesticides was achieved. Simultaneous ozonation and adsorption in the same reactor seems to be the most promising option for this study.
Transport of nutrients and eutrophication control by an urban runoff diversion system protecting a drinking water reservoir
Authors: Tran M. L. , Bahng J. , Pankratz S. , Suffet I. H.
Published: August 2008

Urban runoff from five storms during the 2003–2004 and 2004–2005 rainy seasons was sampled at the exit point of runoff diversion forebays leading to engineered retention ponds to protect a drinking water reservoir. Samples were collected from three different drainage areas both years and were analysed for water quality parameters including total dissolved solids, electrical conductivity (EC), dissolved organic carbon, bacterial count and nutrients in the water phase. In the second year of the study, samples were also taken at the entry point into the forebays and analysed to determine if the forebays contributed to removal of analytes prior to diversion in the retention ponds. EC, which had been used as the determining factor of whether runoff is used to recharge or diverted to holding ponds, did not relate to nutrient levels. This indicated that EC is insufficient to determine water quality because runoff with low EC may contain high levels of nutrients that can support eutrophication. Monitoring of nutrients themselves is essential for decisions.
Operational management of Naegleria spp. in drinking water supplies in Western Australia
Authors: Trolio R. , Bath A. , Gordon C. , Walker R. , Wyber A.
Published: August 2008

Naegleria fowleri is a free-living amoeboflagellate inhabiting soil and water that can cause Primary Amoebic Meningoencephalitis (PAM), a rare and sometimes fatal disease. In Australia, the amoeba typically inhabits drinking water supplies that have consistent water temperatures above 20°C. The incidence of PAM is widespread in Australia, with reports from South Australia, Western Australia, New South Wales and Queensland. One of the key issues for water utilities is the potential widespread distribution of N. fowleri and its ability to infect and re-infect drinking water supplies. In Western Australia, the majority of drinking water supplies are operated by the Water Corporation. This paper describes the conditions under which Naegleria spp. have been detected and describes the operational methods employed by the Water Corporation to control and mitigate Naegleria in public drinking water supplies.
Novel on-tap passive sampling for odorous compounds in drinking water
Authors: Tondelier Christophe , Benanou David , Thouvenot Thomas , Genin Arnaud
Published: August 2008

Because taste and odour events in drinking water are often fleeting and unpredictable phenomena, an innovating passive sampler has been developed to trap off-flavour compounds, directly at the tap of the consumer: ARISTOT (Advanced Relevant Investigation Sampler for Taste & Odour at Tap). Each tool is equipped with seven SBSE stir bars, magnetic stirring roads coated with a polydimethylsiloxane (PDMS) phase, allowing the sorption of water organic compounds into PDMS at each tap opening. To study the efficiency of these passives samplers, a private network pilot unit has been created in our laboratory, equipped with four faucets in series, solenoids valves for automation of the system and a mixing chamber, developed to spike drinking water with odourous compounds in order to have homogenous smelling water at each tap. After enrichment, the bars are taken out and are then in-line thermo-desorbed and analysed by gas chromatography coupled with a mass spectrometer. Results showed a high sensitivity of the system, which was able to quickly analyse odourous compounds at the sub ng/L level. A “multishot” method was developed to analyse every molecule trapped on the seven stir bars in only one chromatographic run increasing sensitivity. To follow enrichment of stir bars, loading and unloading were studied and showed a very slight unloading of the stir bar under a clean water flow rate which allowed us to previously spike every stir bar with an internal standard to see analytical variations. The influence of heated water was also investigated and seems to lead to a higher unloading of the stir bar, but according to a qualitative aspect this loss is balanced by the high sensitivity.
Oxidative Stress Regulates Adipocyte Apolipoprotein E and Suppresses Its Expression in Obesity
Authors: Espiritu Doris Joy , Mazzone Theodore
Published: August 2008

OBJECTIVE—Endogenous expression of apolipoprotein E (apoE) has a significant impact on adipocyte lipid metabolism and is markedly suppressed in obesity. Adipose tissue oxidant stress is emerging as an important mediator of adipocyte dysfunction. These studies were undertaken to evaluate the role of oxidant stress for regulation of adipocyte apoE.

RESEARCH DESIGN AND METHODS—ApoE gene and protein expression in 3T3-L1 adipocytes or mature adipocytes and adipose tissue from C57/BL6 mice was evaluated after induction of oxidant stress. The response of adipose tissue and adipocytes from obese compared with lean mice to antioxidants was also assessed.

RESULTS—Oxidant stress in 3T3-L1 cells or adipocytes and adipose tissue from lean mice significantly reduced apoE mRNA and protein level. Inclusion of an antioxidant eliminated this reduction. Oxidant stress was accompanied by activation of the nuclear factor-κB (NF-κB) transcription complex, and its effect on apoE was eliminated by an NF-κB activation inhibitor. Treatment of freshly isolated adipose tissue or mature adipocytes from obese mice with antioxidant increased apoE expression but had no effect on cells or tissue from lean mice. Incubation of freshly isolated adipocytes from lean mice with stromovascular cells from obese mice significantly suppressed adipocyte apoE compared with incubation with stromovascular cells from lean mice, but this suppression was reversed by inclusion of antioxidant or a neutralizing antibody to tumor necrosis factor-α.

CONCLUSIONS—Oxidant stress significantly modulates adipose tissue and adipocyte apoE expression. Furthermore, oxidant stress contributes to suppression of adipocyte apoE in obesity. This suppression depends on interaction between adipose tissue stromovascular cells and adipocytes.
Financial and Clinical Impact of Team-Based Treatment for Medicaid Enrollees With Diabetes in a Federally Qualified Health Center
Authors: Scanlon Dennis P. , Hollenbeak Christopher S. , Beich Jeff , Dyer Anne-Marie , Gabbay Robert A. , Milstein Arnold
Published: August 2008

OBJECTIVE—The purpose of this study was to determine whether multidisciplinary team-based care guided by the chronic care model can reduce medical payments and improve quality for Medicaid enrollees with diabetes.

RESEARCH DESIGN AND METHODS—This study was a difference-in-differences analysis comparing Medicaid patients with diabetes who received team-based care versus those who did not. Team-based care was provided to patients treated at CareSouth, a multisite rural federally qualified community health center located in South Carolina. Control patients were matched to team care patients using propensity score techniques. Financial outcomes compared Medicaid (and Medicare for dually eligible patients) payments 1 year before and after intervention. Trends over time in levels of A1C, BMI, and systolic blood pressure (SBP) were analyzed for intervention patients during the postintervention period.

RESULTS—Although average claims payments increased for both the CareSouth patients and control patients, there were no statistically significant differences in total payments between the two groups. In the intervention group, patients with A1C >9 at baseline experienced an average reduction of 0.75 mg/dl per year (95% CI 0.50–0.99), patients with BMI >30 at baseline had an average reduction of 2.3 points per year (95% CI 0.99–3.58), and patients with SBP >140 mmHg at baseline had an average reduction of 2.2 mmHg per year (95% CI 0.44–3.88).

CONCLUSIONS—Team-based care following the chronic care model has the potential to improve quality without increasing payments. Short-term savings were not evident and should not be assumed when designing programs.
Neonatal Diabetes With End-Stage Nephropathy
Authors: Esmatjes Enric , Jimenez Amanda , Diaz Gonzalo , Mora Mireia , Casamitjana Roser , Pérez de Nanclares G. , Castaño Luis , José Ricart Maria
Published: August 2008

OBJECTIVE—To describe the diagnosis of a patient with neonatal diabetes who had been misdiagnosed with type 1 diabetes and referred to our hospital for pancreas and kidney transplantation because of end-stage renal disease.

RESEARCH DESIGN AND METHODS—A diagnosis of neonatal diabetes was made after a molecular genetic study revealed a mutation in exon 34 of the ABCC8 gene. Pancreas transplantation was ill-advised.

RESULTS—The patient was switched from insulin to glibenclamide 4 months after kidney transplantation, confirming that pancreas transplantation would not have been a good decision.

CONCLUSIONS—This is the first report of a patient with neonatal diabetes who developed diabetic nephropathy that progressed to end-stage renal disease. This report illustrates that careful endocrinological evaluation, including molecular genetic studies, if necessary, is mandatory before a decision to perform a pancreas transplant is made.
Mahovna Flora Smrekovškega Pogorja (Kamniško-Savinjske Alpe, Slovenija)
Authors: Martinčič Andrej
Published: August 2008

Mahovna Flora Smrekovškega Pogorja (Kamniško-Savinjske Alpe, Slovenija)

The study gives results on new bryophyte records of Smrekovško pogorje Mts. as well as the previous reports from the literature. In total 229 species are reported from the investigated region, 173 mosses and 56 liver-worts. Among them 3 are reported for the first time for Slovenia (Sciuro-hypnum oedipodium, Calypogeia integristipula, Lophozia sudetica), 20 species are reported for the first time for the Kamniško-Savinjske Alps (Alpine phytogeographical region of Slovenia). 26 species are included in the national Red List and 4 species in the Red Data Book of European Bryophytes (ECCB 1995), in the rare (R) category:Scapania verrucosa, Brachythecium geheebii, Fissidens asplenioidesandParaleucobryum sauteri.
Photoresponsive Glass‐Forming Butadiene‐Based Chiral Liquid Crystals with Circularly Polarized Photoluminescence
Authors: Vijayaraghavan Ratheesh K. , Abraham Shibu , Akiyama Haruhisa , Furumi Seiichi , Tamaoki Nobuyuki , Das Suresh
Published: August 2008

The synthesis and study of the photo‐ and thermoresponsive behavior of a series of novel trimesogens consisting of a diphenylbutadiene core linked to cholesterol moieties on either side via flexible alkyl chains are reported. These molecules possess the combined glass‐forming properties of bischolesterols and the photochromic and luminescent properties of the butadiene moiety. The pitch of the cholesteric phase of these materials could be continuously varied thermally and photochemically, making it possible to tune the color of the film over the entire visible region. The color images thus generated could be stabilized by converting them to N* glasses. These materials were also highly photoluminescent, exhibiting circularly polarized characteristics in the glassy liquid‐crystalline state even by linearly polarized excitation.
Effect of the origin of ZnO nanoparticles dispersed in polyimide films on their photoluminescence and thermal stability
Authors: Somwangthanaroj Anongnat , Phanthawonge Chuthatai , Ando Shinji , Tanthapanichakoon Wiwut
Published: August 2008

Polyimide (PI) films containing dispersed ZnO nanoparticles were prepared from both zinc nitrate hexahydrate (designated as Zn(NO3)2/PI) and ZnO nanoparticles, 2‐nm average primary size (ZnO/PI). This work shows how the origin of ZnO affects both the photoluminescence and thermal decomposition of the film. The presence of ZnO derived from Zn(NO3)2·6H2O was confirmed by X‐ray diffraction technique. The fluorescent intensities from Zn(NO3)2/PI and ZnO/PI were much higher than that from pure PI films. When the ZnO concentration exceeded a certain saturation level, the emission intensity decreased due to the undesirable aggregation of ZnO. At the same concentration, ZnO/PI exhibited higher emission intensity than Zn(NO3)2/PI. All samples prepared under nitrogen emitted higher intensity than their counterparts prepared under argon. The ZnO/PI film was thermally more stable than the Zn(NO3)2/PI one. From TEM images of 117.6 mol% ZnO/PI films, the ZnO aggregates, whose average size was 17–90 nm, were well distributed throughout the film but poorly dispersed in nanometer range. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Eigenfactor: Does the principle of repeated improvement result in better estimates than raw citation counts?
Authors: Davis Philip M.
Published: August 2008

Eigenfactor.org, a journal evaluation tool that uses an iterative algorithm to weight citations (similar to the PageRank algorithm used for Google), has been proposed as a more valid method for calculating the impact of journals. The purpose of this brief communication is to investigate whether the principle of repeated improvement provides different rankings of journals than does a simple unweighted citation count (the method used by the Institute for Scientific Information@ [ISI]).
The presence of rRNA sequences in polyadenylated RNA and its potential functions
Authors: Kong Qiongman , Stockinger Michael P. , Chang Yueming , Tashiro Hirofumi , Lin Chien‐liang Glenn
Published: August 2008

Accumulating evidence has shown that various lengths of ribosomal RNA (rRNA) sequences are widely present in polyadenylated RNA. This review article will discuss these polyadenylated rRNAcontaining transcripts (PART). PART are highly abundant and widely expressed in various tissues. It appears that there may be two types of PART. One type, type I, contains the rRNA segments (from ∼10 nucleotides up to several hundred nucleotides) located within the transcripts. It has been demonstrated that short rRNA sequences within type I PART may function as cis‐regulatory elements that regulate translational efficiency. The other type, type II, contains large portions or almost entire sequences of rRNA with a cap at the 5' end and poly(A) at 3' end. Recent work has shown that some type II PART have functional significance for some neurodegenerative disease processes and may play an important role in the pathogenesis of diseases. Further investigation in this area is critical to understanding the basic biology of PART and the potential role of PART in diseases.
Tools for the study of ribosome‐borne protein folding activity
Authors: Voisset Cécile , Thuret Jean‐Yves , Tribouillard‐Tanvier Déborah , Saupe Sven J. , Blondel Marc
Published: August 2008

In addition to its role in protein synthesis, which involves a peptidyl transferase activity, the ribosome has also been described to be able to assist protein folding, at least in vitro, as presented in a Research Highlight (Das, et al., Biotechnol. J. 2008). This in vitro‐described ribosome‐borne protein folding activity (RPFA) is yet poorly characterized in vivo, in part because of the lack of tools to study its biological significance. There is substantial evidence documenting RPFA in vitro, and an assay intended to detect this activity in vivo has been set up in bacteria, but this assay is indirect. In this review, we describe the different tools and tests currently available to study RPFA. We put a special emphasis on the various available inhibitors of this activity and in particular, we discuss the use of 6‐aminophenanthridine (6AP) and guanabenz (GA), two antiprion drugs that were very recently shown to specifically inhibit RPFA in vitro without any significant effect on the activity of the ribosome in protein synthesis. Therefore, these drugs should allow determining the potential biological role of RPFA. Importantly, the biological activity of 6AP and GA suggest a possible involvement of RPFA in human proteinopathies.
Adsorption of Atrazine and Simazine from Aqueous Solutions onto Poly(ε‐Caprolactone)
Authors: Ovez Bikem , Höll Wolfgang H.
Published: August 2008

The biodegradable synthetic polymer poly(ε‐caprolactone) was investigated as a substrate for denitrification. This substrate may also act as an adsorbent for two pesticides, i. e., atrazine and simazine, from water. The equilibrium was studied at 25, 35 and 45°C. The results were correlated using the Langmuir and Freundlich adsorption models. The total capacities of the adsorbent were defined from experimental data for atrazine (10.98 mg g–1) and simazine (27.54 mg g–1). The effect of temperature on the model constants and the thermodynamics of adsorption were investigated. The evaluation of the development of adsorption was achieved by assuming a pseudo‐second order chemical reaction.
Fine needle biopsy and genetics, two allied weapons in the diagnosis, prognosis, and target therapeutics of solid pediatric tumors
Authors: Barroca Helena
Published: August 2008

The recognition that genetic defects identify some pediatric solid tumors and may represent prognostic markers has provided cytologists with an extra tool for dealing with such tumors. Using some entities as archetypes, we discuss the importance of the association of fine needle biopsy and genetics, in the diagnosis, prognosis, and therapy selection of solid pediatric tumors. Immunocytochemistry is important to differentiate neuroblastoma, PNET/Ewing sarcoma, alveolar rhabdomyosarcoma, lymphoma, and desmoplastic small round cell tumor. Despite its usefulness in many cases, it is not conclusive and some of the aforementioned tumors even share the expression of some antibodies. The detection of specific diagnostic translocations will thus provide additional information and allows a precise cytologic diagnosis. Kidney tumors are also frequent in children. Although no genetic abnormalities have been identified so far in nephroblastoma, other kidney tumors, such as mesoblastic nephroma, whose cytology pattern can masquerade nephroblastoma, are also characterized by specific translocations. Kidney tumors in children have also been associated recently with typical genetic alterations such as Xp11.2RCC. Concerning prognosis and therapy selection, neuroblastoma is a sort of paradigm. The identification of MYCN oncogene status as an independent prognostic factor is determinant, not only in the assessment of clinical evolution, but also in the identification of risk groups, and consequently in the appropriate therapy selection. Cytopathologists should be aware of the genetic alterations characterizing pediatric tumors in order to collect extra material to perform cytogenetics, FISH, PCR, and Southern blotting, to achieve the correct identification of such genetic changes. Diagn. Cytopathol. 2008;36:678–684. © 2008 Wiley‐Liss, Inc.
Myxoid liposarcoma of the breast in a 25‐year‐old female as a diagnostic pitfall in fine needle aspiration cytology: Report of a rare case
Authors: Pant Ishita , Kaur Gurjeet , Joshi Sanjeev Chandra , Khalid Imran Abdul
Published: August 2008

Primary sarcomas of the breast are extremely rare comprising less than 1.0% of all malignant tumors of the breast. It is even rarer to be reported in a 25‐year‐old female. This can cause a diagnostic dilemma not only for the clinician but also for the cytopathologist.

A 25‐year‐old woman presented with a well defined firm, mobile lump in her right breast. With fine needle aspiration cytology (FNAC) and ultrasonography a diagnosis of fibroadenoma was made. The patient underwent lumpectomy. Histopathologically it was diagnosed as myxoid liposarcoma.

This case is reported to highlight the fact that, even though rare in young females but the possibility of a breast lump being a myxoid liposarcoma does exist. This report discusses a primary myxoid liposarcoma of female breast, considers cytologic differential diagnoses with review of the relevant literature. Diagn. Cytopathol. 2008;36:674–677. © 2008 Wiley‐Liss, Inc.
H‐Bonded Porous Supramolecular Network of a CuII Complex Assisted by Assembled 2D Sheet of Chair Form Hexameric Water Cluster
Authors: Siddiqui Kafeel Ahmad , Mehrotra Gopal K. , Mrozinski Jerzy , Butcher Raymond J.
Published: August 2008

The supramolecular network of the complex having the formula [Cu(nicot)2·2NH3·2H2O]·6H2O 1 has been synthesized by transmetallation of the Zn–nicotinate complex by CuII ions and its crystallization in an ionic liquid. The supramolecular network of 1 shows unique H‐bonding in the sense that it not only participates in the formation of nanoporous 2D chains but also forms cyclic hexameric water cluster that adopt an ice‐like chair conformation, which together with octanuclear H‐bonded rings extend the network into a 3D open framework. X‐ray structural analysis, FTIR, thermal analysis, EPR and magnetic properties have been used to characterize this compound. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Heavier Group‐2‐Element Catalyzed Hydroamination of Carbodiimides
Authors: Lachs Jennifer R. , Barrett Anthony G. M. , Crimmin Mark R. , Kociok‐Köhn Gabriele , Hill Michael S. , Mahon Mary F. , Procopiou Panayiotis A.
Published: August 2008

The heteroleptic calcium amide [{ArNC(Me)CHC(Me)NAr}Ca{N(SiMe3)2}(THF)] (Ar = 2,6‐diisopropylphenyl) and the homoleptic heavier alkaline earth amides, [M{N(SiMe3)2}2(THF)2] (M = Ca, Sr and Ba) are reported as competent pre‐catalysts for the hydroamination of 1,3‐carbodiimides. Whilst the reaction scope is currently limited to reactions of aromatic amines with 1,3‐dialkylcarbodiimides, in most cases preparations in hydrocarbon solvents proceed rapidly at room temperature with catalyst loadings as low as 0.2 mol‐% and the guanidine reaction products crystallize directly from the reaction mixture. Initial studies are consistent with the intermediacy of heavier group‐2 guanidinate complexes.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Protection/Deprotection‐Free Syntheses and Structural Analysis of (Keto‐aryl)diynes
Authors: Osowska Karolina , Lis Tadeusz , Szafert Sławomir
Published: August 2008

The reactions of precursors 4‐BrC6H4COR with TMSC≡CH (Sonogashira coupling) followed by in situ deprotection and subsequent dimerization gave thermally stable dimeric keto‐diynes RCOC6H4(C≡C)2C6H4COR (8–11) as yellow powders in 25–85 % yields without the necessity of carbonyl group protection/deprotection steps. Compounds 8–11 were also synthesized by an alternative method that utilized α‐haloalkynes previously obtained directly from TMS‐protected 4‐RCOC6H4C≡CTMS alkynes. The resulting diynes were characterized by spectroscopic methods and in most cases by X‐ray crystallography. Careful analysis of the crystal data revealed a surprisingly high degree of chain curvature. Moreover, compounds 9 (R = Me) and 10 (R = Et) were extremely flat, which greatly facilitates electronic communication throughout the whole molecule. Deeper analysis of the packing motifs showed 9 to have a great potential for topochemical 1,4‐polymerization.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrocatalytic Determination of 6‐Tioguanine at a p‐Aminophenol Modified Carbon Paste Electrode
Authors: Mirmomtaz Elham , Asghar Ensafi Ali , Karimi‐Maleh Hassan
Published: August 2008

A p‐aminophenol modified carbon paste electrode (p‐APMCPE) was constructed for determination of an anticancer drug 6‐thioguanine (6‐TG). The cyclic voltammogram showed that the electrocatalytic oxidation of 6‐TG at the surface of p‐APMCPE occurs at a potential about 840 mV less positive than at an unmodified electrode. Square‐wave voltammetry results presented that the electrocatalytic oxidation peak currents of 6‐TG in pH 9.0 had two linear dynamic ranges in the range of 0.2 to 8.0 and 8.0 to 350.0 μM 6‐TG with a detection limit of 0.08 μM. The kinetic parameters such as electron transfer coefficient (α) and rate constant were determined for the chemical reaction between 6‐TG and p‐aminophenol. Finally, this method was evaluated for the determination of 6‐TG in 6‐thioguanine tablets and urine samples.
PVC Supported Liquid Membrane and Carbon Paste Potentiometric Sensors Incorporating a Mn(III)‐Porphyrin for the Direct Determination of Undissociated Paracetamol
Authors: Saraswathyamma Beena , Pająk Marta , Radecki Jerzy , Maes Wouter , Dehaen Wim , Girish Kumar Krishnapillai , Radecka Hanna
Published: August 2008

PVC supported liquid membrane and carbon paste potentiometric sensors incorporating an Mn(III)‐porphyrin complex as a neutral host molecule were developed for the determination of paracetamol. The measurements were carried out in solution at pH 5.5. Under such conditions paracetamol exists as a neutral molecule. The mechanism of molecular recognition between the Mn(III)‐porphyrin and paracetamol, leading to potentiometric signal generation, is discussed.
Electrochemically Active Mercury Nanodroplets Trapped in a Carbon Nanoparticle–Chitosan Matrix
Authors: Rassaei Liza , Sillanpää Mika , Edler Karen J. , Marken Frank
Published: August 2008

A thin composite film of carbon nanoparticles (ca. 8 nm diameter) and chitosan biopolymer (poly‐D‐glucosamine, from chitin, 75–85% deacetylated) was prepared by evaporation from aqueous dispersion onto glassy carbon electrode surfaces. The amine groups in the chitosan biopolymer were used to effectively bind Hg(II) ions from an aqueous pH 5 KCl solution. During redox cycling voltammetric responses for bound mercury are readily observed and mercury nanodroplets (ca. 5.4 (±1.0) nm diameter based on SAXS measurements) are formed in the film by applying a negative potential. The binding of Hg(II) ions to the chitosan–carbon nanoparticle film occurs with an approximate Langmuirian constant of 2.7×104 mol−1dm3 and the process is dependent on (i) the chitosan content in the film, (ii) the Hg2+ concentration, and (iii) the immobilization time. The immobilized mercury nanodroplets within the carbon nanoparticle–chitosan film are electrochemically active and allow the co‐deposition of other metals in the form of amalgams. Preliminary experiments for the anodic stripping voltammetry for Pb2+ and for Cu2+ are demonstrated. Mercury nanodroplet modified chitosan–carbon nanoparticle film electrodes represent a novel electroanalytical tool.
An innovative methodology for seismic retrofitting of existing RC buildings by metal shear panels
Authors: De Matteis G. , Formisano A. , Mazzolani F. M.
Published: August 2008

In the present paper, the seismic upgrading of existing reinforced concrete (RC) structures by means of steel and pure aluminium shear panels is examined. After a preliminary experimental evaluation of the performance of the bare RC structure, a design approach based on the capacity spectrum method has been developed according to the procedure provided in the ATC 40 American guidelines. First, the geometrical configuration of the applied shear panels has been defined according to simplified analytical relationships, while appropriate steel members have been designed to allow the insertion of shear panels in the existing RC structure. Then, complex finite element models have been implemented in order to check the reliability of the proposed design procedure. Also, a numerical evaluation of the global response of the upgraded structure has been processed aiming at evaluating the interaction between the RC structure and the metal devices. Finally, the effectiveness of the applied shear panels has been proven by means of full‐scale experimental tests, which confirmed the significant improvement of the RC structure performance, in terms of strength, stiffness and deformation capacity. Copyright © 2008 John Wiley & Sons, Ltd.
Aeolian activity at a giant sandstone weathering pit in arid south‐central Utah
Authors: Netoff Dennis I. , Chan Marjorie A.
Published: August 2008

Aeolian abrasional, depositional and deflational features indicate exceptionally strong southwesterly winds in a giant sandstone weathering pit in Grand Staircase Escalante Monument, about 22 km southeast of Escalante, Utah. The 60 m wide, 5–20 m deep pit has developed near the summit of a broad, barren 160‐m‐high dome on the Lower Jurassic Navajo Sandstone. Unlike other giant weathering pits (10–30 m diameter) in the region, the bedrock floor of this pit is undulatory, and there is a cylindrical, 10‐m‐high rock pedestal in the centre of the pit. An active dune surrounds the central pedestal and at times has as much as 8 m of local relief. The dune shifts considerably over brief (<1 year) periods of time. Fine‐grained (<250 µm) dunal sand on the pit floor is periodically removed by deflation, leaving coarser sand (>250 µm) trapped in the pit. Dunal sand is typically derived from external sources (other than the pit walls and floor). Centimetre to metre‐scale abrasional features such as grooves, flutes and dedos occur on the bedrock walls and floor of the pit. These dedos and other streamlined aeolian sculpted host‐rock features occur in clusters and typically form in the lee of iron concretions. The dedos are similar to the controversial stalked blueberries on Mars. Above the western rim of the pit there is a 29‐m‐long, 5‐m‐wide aeolian groove with a fluted bedrock floor. A 1·2‐km‐long bedrock valley descends to the southwest from the pit and groove, amplifying southwesterly winds. Data from hand‐held anemometers suggest that southwesterly winds can be accelerated 200–300 per cent or more by local topography. Copyright © 2008 John Wiley and Sons, Ltd.
Qualitative and quantitative applications of LiDAR imagery in fluvial geomorphology
Authors: Notebaert Bastiaan , Verstraeten Gert , Govers Gerard , Poesen Jean
Published: August 2008

The potential for geomorphological mapping and quantitative calculations of light detection and ranging (LiDAR) data within fluvial geomorphology was studied for two river catchments within Belgium (Dijle and Amblève), which differ in physical settings and floodplain morphology. Two commercial, of‐the‐shelf LiDAR datasets with different specifications (horizontal resolution and vertical accuracy) were available for parts of the floodplains of both catchments. Real‐time kinematic (RTK) Global Positioning System (GPS) data were used as ground truth for error calculations.

Qualitative analysis of LiDAR data allowed the identification of former channel patterns, levees, colluvial hillslope and fan deposits. These results were confirmed by field data, topographic surveys and historical maps. The pixel resolution proved to be an important factor in the identification of small landforms: only features with a width equal to or larger than LiDAR resolution can be detected. This poses limits on the usability of regionally available LiDAR data, which often have a horizontal resolution of several metres.

The LiDAR data were also used in a quantitative analysis of channel dynamics. In the study area, the width of the Dijle River channel increased 3 m on average between 1969 and 2003. A sediment budget of channel processes for the period 1969–2003 indicated a total river bank erosion of 16·1 103 m3 and a total within channel deposition of 7·1 103 m3, resulting in a net river erosion of 9·0 103 m3 or c. 0·4 Mg year−1 per metre river length. Sequential LiDAR data can in theory be used to calculate vertical sedimentation rates, as long as there is control on the error of the reference levels used. Copyright © 2008 John Wiley and Sons, Ltd.
The effect of shrub canopy upon surface temperatures and evaporation in the Negev Desert
Authors: Kidron Giora J.
Published: August 2008

Although known as ‘islands of fertility’ or ‘resource islands’, information regarding the effect of shrubs upon microclimate in deserts is scarce. Here we report on measurements of evaporation and temperatures that were carried out in and around a pair of shrubs at the Nizzana research site in the western Negev Desert during 1993–94 and during the growing season (November–March) of 1994–95 and 1996–1997. Whereas evaporation was measured monthly using mini‐atmometers (10 cm diameter and 10 cm tall) at an exposed site and under and around the shrub (at the eastern, southern, western and northern aspects), temperature was measured under a shrub canopy, at its northern aspect, and at an exposed habitat. Evaporation was aspect dependent with increasing rates in the following order: exposed > south‐facing > west‐facing ≈ east‐facing > north‐facing > under canopy. Except from the northern aspect, the under‐canopy habitat showed substantially lower rates of evaporation in comparison with all other habitats. The differences between the under‐canopy and the exposed habitat were larger during wintertime (with the under‐canopy habitat having 0·53 times the evaporation rate than that of the exposed habitat) although higher differences in temperatures characterized both habitats in summertime (up to 14·4 °C in summer as compared with 6·9 °C only in winter). The results were explained by extended surface wetness that characterized the under‐canopy habitat following rainstorms. While already being dried out at the exposed habitat, surface wetness at the under canopy habitat persisted for several days afterwards, resulting, following one rainstorm, in vapour pressure of 2·15–2·39 kPa in comparison with only 0·82–0·83 kPa of the exposed habitat. The substantially lower evaporation rates that characterize the under‐canopy habitat may thus play a pivotal role in providing preferential conditions for lush under‐canopy annual growth. Copyright © 2008 John Wiley and Sons, Ltd.
Flow energy and channel adjustments in rills developed in loamy sand and sandy loam soils
Authors: Stefanovic Jovan R. , Bryan Rorke B.
Published: August 2008

The storms usually associated with rill development in nature are seldom prolonged, so development is often interrupted by interstorm disturbances, e.g. weathering or tillage. In laboratory simulated rainfall experiments, active rill development can be prolonged, and under these conditions typically passes through a period of intense incision, channel extension and bifurcation before reaching quasi‐stable conditions in which little form change occurs. This paper presents laboratory experiments with coarse textured soils under simulated rainfall which show how channel adjustment processes contribute to the evolution of quasi‐stability.

Newly incised rills were stabilized for detailed study of links between rill configuration and flow energy. On a loamy sand, adjustment towards equilibrium occurred due to channel widening and meandering, whereas on a sandy loam, mobile knickpoints and chutes, pulsations in flow width and flow depth and changes in stream power and sediment discharge occurred as the channel adjusted towards equilibrium. The tendency of rill systems towards quasi‐stability is shown by changes in stream power values which show short‐lived minima. Differences in energy dissipation in stabilized rills indicate that minimization of energy dissipation was reached locally between knickpoints and at the downstream ends of rills. In the absence of energy gradients in knickpoints and chutes, stabilized rill sections tended toward equilibrium by establishing uniform energy expenditure. The study confirmed that energy dissipation increased with flow aspect ratio. In stabilized rills, flow acceleration reduced energy dissipation on the loamy sand but not on the sandy loam. On both soils flow deceleration tended to increase energy dissipation.

Understanding how rill systems evolve towards stability is essential in order to predict how interruptions between storms may affect long‐term rill dynamics. This is essential if event‐based physical models are to become effective in predicting sediment transport on rilled hillslopes under changing weather and climatic conditions. Copyright © 2008 John Wiley and Sons, Ltd.
Nonalcoholic steatohepatitis is associated with altered hepatic MicroRNA expression
Authors: Cheung Onpan , Puri Puneet , Eicken Christoph , Contos Melissa J. , Mirshahi Faridoddin , Maher James W. , Kellum John M. , Min Haeki , Luketic Velimir A. , Sanyal Arun J.
Published: August 2008

The expression of microRNA in nonalcoholic steatohepatitis (NASH) and their role in the genesis of NASH are not known. The aims of this study were to: (1) identify differentially expressed microRNAs in human NASH, (2) tabulate their potential targets, and (3) define the effect of a specific differentially expressed microRNA, miR-122, on its targets and compare these effects with the pattern of expression of these targets in human NASH. The expression of 474 human microRNAs was compared in subjects with the metabolic syndrome and NASH versus controls with normal liver histology. Differentially expressed microRNAs were identified by the μParaflo microRNA microarray assay and validated using quantitative real-time polymerase chain reaction (PCR). The effects of a specific differentially expressed miRNA (miR-122) on its predicted targets were assessed by silencing and overexpressing miR-122

in vitro

. A total of 23 microRNAs were underexpressed or overexpressed. The predicted targets of these microRNAs are known to affect cell proliferation, protein translation, apoptosis, inflammation, oxidative stress, and metabolism. The miR-122 level was significantly decreased in subjects with NASH (63% by real-time PCR,

P

< 0.00001). Silencing miR-122 led to an initial increase in mRNA levels of these targets (

P

< 0.05 for all) followed by a decrease by 48 hours. This was accompanied by an increase in protein levels of these targets (

P

< 0.05 for all). Overexpression of miR-122 led to a significant decrease in protein levels of these targets.

Conclusions

: NASH is associated with altered hepatic microRNA expression. Underexpression of miR-122 potentially contributes to altered lipid metabolism implicated in the pathogenesis of NASH. (Hepatology 2008;48:1810–1820.)
Circadian rhythm disturbances in depression
Authors: Germain Anne , Kupfer David J.
Published: August 2008

Objective

The aim of this article is to review progress in understanding the mechanisms that underlie circadian and sleep rhythms, and their role in the pathogenesis and treatment of depression.

Methods

Literature was selected principally by Medline searches, and additional reports were identified based on ongoing research activities in the authors' laboratory.

Results

Many physiological processes show circadian rhythms of activity. Sleep and waking are the most obvious circadian rhythms in mammals. There is considerable evidence that circadian and sleep disturbances are important in the pathophysiology of mood disorders. Depressed patients often show altered circadian rhythms, sleep disturbances, and diurnal mood variation. Chronotherapies, including bright light exposure, sleep deprivation, and social rhythm therapies, may be useful adjuncts in non‐seasonal and seasonal depression. Antidepressant drugs have marked effects on circadian processes and sleep.

Conclusions

Recent progress in understanding chronobiological and sleep regulation mechanisms may provide novel insights and avenues into the development of new pharmacological and behavioral treatment strategies for mood disorders. Copyright © 2008 John Wiley & Sons, Ltd.
Bone grafts cultured with bone marrow stromal cells for the repair of critical bone defects: An experimental study in mice
Authors: Dumas Aline , Moreau Marie‐Françoise , Ghérardi Romain K. , Baslé Michel F. , Chappard Daniel
Published: August 2008

Tissue engineering of autologous bone combined with osteoprogenitor cells is a suitable strategy for filling large bone defects. The aim of this study was to evaluate the osteogenicity of a xenogenic bone graft cultured with allogenic bone marrow stromal cells (BMSC) in a mouse critical size craniotomy. Bovine trabecular bone grafts were made free of bone marrow cells or debris and were delipidated. BMSC were harvested from C57BL/6‐Tg(ACTbEGFP)1Osb/J mice (GFP+ cells) and were cultured 14 days on bone grafts in control or osteogenic medium. Engineered grafts were implanted in calvarial defect in C57BL/6 mice. Four groups were studied: graft with BMSC differentiated in osteoblasts (G‐Ob), graft with BMSC (G‐BMSC), graft without cells (G) and no graft. Calvariae were studied 2 and 8 weeks after implantation by radiographic and histomorphometric analyses. G group: the bone ingrowth was limited to the edges of the defect. The center of the graft was filled by a fibrovascular connective tissue. G‐BMSC or G‐Ob groups: bone formation occurred early in the center of the defect and did not increase between 2 and 8 weeks; the newly formed woven bone was partially replaced by lamellar bone. The preoperative osteoblastic differentiation of BMSC did not allow faster and better bone regeneration. After 2 weeks, GFP+ cells were observed around the grafted bone but no GFP+ osteocyte was present in the newly formed bone. No GFP+ cell was noted after 8 weeks. However, pre‐implantation culture of the biomaterial with allogenic BMSC greatly enhanced the bone regeneration. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
A versatile mesoindentation system to evaluate the micromechanical properties of soft, hydrated substrates on a cellular scale
Authors: Saxena Tarun , Gilbert Jeremy L. , Hasenwinkel Julie M.
Published: August 2008

It has become increasingly important to study mechanical properties of substrates on the cellular scale since cells sense and respond to changes in the microenvironment in which they are grown. To study the effects of mechanical substrate properties on the cellular scale, an existing microindentation system has been modified to perform indentation tests on highly hydrated polymeric substrates and tissues. The highly sensitive, modified indentation system, labeled as a mesoindenter, is versatile and can be customized to perform a variety of tests useful for studying tissue mechanics, stress relaxation in polymers, and interfacial adhesion phenomena. To validate the efficacy and accuracy of the system, soft, hydrated hydrogels made from agarose (1–5 wt %), poly(2‐hydroxyethyl methacrylate) (p(HEMA)) (60–90% water), and unfixed, saline‐perfused rat spinal cord tissue were tested. The results demonstrate that moduli vary with water content and are in line with previously published studies. We also demonstrate that the modulus of hydrogels is sensitive to the preload applied, with modulus increasing with preload. Stress relaxation indentation testing of p(HEMA) showed relaxation behavior that can be modeled using a heredity integral and standard linear model. The mesoindenter is versatile, capable of scanning and testing immersed samples, and easily customized to ascertain mechanical properties of substrates ranging from the kPa to GPa range. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Titanium IV ions induced human osteoclast differentiation and enhanced bone resorption in vitro
Authors: Cadosch Dieter , Chan Erwin , Gautschi Oliver P. , Meagher James , Zellweger René , Filgueira Luis
Published: August 2008

There is increasing evidence that titanium (Ti) ions are released from orthopedic implants, with concentrations in the range of 1 μM in tissue and blood, and may play a role in aseptic loosening of orthopedic implants. This study investigated whether Ti(IV) ions induce differentiation of monocytic osteoclast precursors into osteo‐resorptive multinucleated cells and influence the activation and function of in vitro generated osteoclasts. Human monocytes and in vitro generated osteoclasts were exposed to 1 μM Ti(IV) ions for 10 days. Thereafter, osteoclast differentiation, activation, and function were evaluated. Transcription of specific osteoclastic genes was measured using quantitative reverse transcription polymerase chain reactions, which showed increased expression of tartrate‐resistant acid phosphatase (TRAP) in ∼20% of Ti(IV)‐treated monocytes. Detection and quantification of intracellular TRAP activity using ELF97 as a fluorescent substrate revealed a significant increase of TRAP‐positive cells in Ti(IV)‐treated monocytes. Additionally, as demonstrated on dentin slide cultures, Ti(IV)‐treated monocytes became functional bone resorbing cells, significantly increasing their osteo‐resorptive activity to similar levels as osteoclasts in vitro. These results suggest that Ti(IV) ions released by biocorrosion from orthopedic implants induce differentiation of monocytes toward mature, functional osteoclasts, which may well contribute the pathomechanism of aseptic loosening. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009