bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of reinforced concrete through SPH‐FE coupling and its application to the simulation of a projectile's impact onto a slab
Authors: Caleyron F. , Chuzel‐Marmot Y. , Combescure A.
Published: October 2009

The analysis of structural behavior under extreme solicitations such as crash and impact requires the modeling of fragmentation, rupture and large deformation phenomena. The use of finite elements (FE) in this type of problem is not easy, mainly because this approach relies on a mesh that cannot handle distortions and tearing well. In order to circumvent this difficulty, methods termed ‘meshless’, such as the smoothed particle hydrodynamics (SPH) method, have been devised. These methods enable one to undertake numerical simulations involving the extreme types of behavior mentioned above. Thus, for example, the simulation of a projectile's impact onto a reinforced concrete slab can be easily envisaged. One's wish to carry out predictive calculations raises the question of the modeling of the reinforcement. It is tempting to use an SPH formulation for the slab and a beam FE formulation for the reinforcement. Therefore, the problem boils down to the coupling of two structures modeled with two different formulations: the slab with an SPH formulation, and the reinforcement with a FE formulation. This paper presents the development of a theory based on the use of Lagrange multipliers, which enable the coupling of a structure modeled with SPH with a structure modeled with beam FEs. This theory was implemented into the EUROPLEXUS fast dynamics software, then validated through simple test cases. Finally, the program was applied to the simulation of a projectile's impact onto a reinforced concrete slab.The aim of this work is to propose an alternative method to smeared representations of reinforcements in concrete. Indeed, smeared representations of reinforced concrete are widely used but do not represent explicitly the reinforcement, which is fundamental to study impacts onto the rebars and phenomenons such as separation of the reinforcement from the concrete or fracture of the rebars. Copyright © 2009 John Wiley & Sons, Ltd.
First experience of compressible gas dynamics simulation on the Los Alamos roadrunner machine
Authors: Woodward Paul R. , Jayaraj Jagan , Lin Pei‐Hung , Dai William
Published: October 2009

We report initial experience with gas dynamics simulation on the Los Alamos Roadrunner machine. In this initial work, we have restricted our attention to flows in which the flow Mach number is less than 2. This permits us to use a simplified version of the PPM gas dynamics algorithm that has been described in detail by Woodward (2006). We follow a multifluid volume fraction using the PPB moment‐conserving advection scheme, enforcing both pressure and temperature equilibrium between two monatomic ideal gases within each grid cell. The resulting gas dynamics code has been extensively restructured for efficient multicore processing and implemented for scalable parallel execution on the Roadrunner system. The code restructuring and parallel implementation are described and performance results are discussed. For a modest grid size, sustained performance of 3.89 Gflops−1 CPU‐core−1 is delivered by this code on 36 Cell processors in 9 triblade nodes of a single rack of Roadrunner hardware. Copyright © 2009 John Wiley & Sons, Ltd.
DNA Condensation by Field‐Induced Non‐Equilibrium Noise
Authors: Bruinsma Robijn F. , Riehn Robert
Published: October 2009

DNA molecules under good solvent conditions condense when subjected to strong AC electrical fields. It is shown that AC electrical fields couple charge fluctuations to molecular shape fluctuations, which produces a non‐equilibrium noise source that can dominate over equilibrium thermal noise in the long‐wavelength limit. The field‐induced excess charge fluctuations amplify the Asakura–Oosawa fluctuation attraction force between neighboring chains, providing a mechanism for field‐induced DNA condensation.
Temperature dependence of photoluminescence from ordered GaInP2 epitaxial layers
Authors: Prutskij T. , Pelosi C.
Published: October 2009

The temperature behavior of the integrated intensity of photoluminescence (PL) emission from ordered GaInP2 epitaxial layer was measured at temperatures of 10 ‐ 300 K. Within this temperature range the PL emission is dominated by band‐to‐band radiative recombination. The PL intensity temperature dependence has two regions: at low temperatures it quenches rapidly as the temperature increases, and above 100 K it reduces slowly. This temperature behavior is compared with that of disordered GaInP2 layer. The specter of the PL emission of the disordered layer has two peaks, which are identified as due to donor‐accepter (D‐A) and band‐to‐band recombination. The PL intensity quenching of these spectral bands is very different: With increasing temperature, the D‐A peak intensity remains almost unchanged at low temperatures and then decreases at a higher rate. The intensity of the band‐to‐band recombination peak decays gradually, having a higher rate at low temperatures than at higher temperatures. Comparing these temperature dependencies of these PL peaks of ordered and disordered alloys and the temperature behavior of their full width at half maximum (FWHM), we conclude that the different morphology of these alloys causes their different temperature behavior. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the substrate temperature on the structural, optical, and electrical properties of tin selenide thin films deposited by thermal evaporation method
Authors: Kumar N. , Sharma V. , Padha N. , Shah N. M. , Desai M. S. , Panchal C. J. , Protsenko I. Yu.
Published: October 2009

Thin films of tin selenide (SnSe) were deposited on sodalime glass substrates, which were held at different temperatures in the range of 350‐550 K, from the pulverized compound material using thermal evaporation method. The effect of substrate temperature (Ts) on the structural, morphological, optical, and electrical properties of the films were investigated using x‐ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission measurements, and Hall‐effect characterization techniques. The temperature dependence of the resistance of the films was also studied in the temperature range of 80‐330 K. The XRD spectra and the SEM image analyses suggest that the polycrystalline thin films having uniform distribution of grains along the (111) diffraction plane was obtained at all Ts. With the increase of Ts the intensity of the diffraction peaks increased and well‐resolved peaks at 550 K, substrate temperature, were obtained. The analysis of the data of the optical transmission spectra suggests that the films had energy band gap in the range of 1.38‐1.18 eV. Hall‐effect measurements revealed the resistivity of films in the range 112‐20 Ω cm for films deposited at different Ts. The activation energy for films deposited at different Ts was in the range of 0.14 eV‐0.28 eV as derived from the analysis of the data of low‐temperature resistivity measurements. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characterization of L‐valine ‐ a nonlinear optical crystal
Authors: Moitra S. , Kar T.
Published: October 2009

The growth of a new nonlinear optical material L‐valine by solvent evaporation method is reported here. To grow good quality crystals pH value of growth solution has been optimized and solubility of L‐valine in different solvents and different pH values was determined. The grown crystals were characterized by IR, single crystal XRD, DTA and TGA, optical transmission and second harmonic generation (SHG) efficiency measurement. SHG efficiency of L‐valine was found equivalent to KDP and its transmission is 75%‐80% from ultraviolet to near IR region. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐Hamiltonian parameters and local lattice structure for Pd(I) center in γ‐irradiated bis(acetylacetonato)palladium(II)
Authors: Feng W. L. , Zeng T. X. , Chen T. H. , Chen J. J.
Published: October 2009

This paper reports on a theoretical analysis of spin‐Hamiltonian parameters and local lattice structure for Pd(I) center in γ‐irradiated Pd(II)(acac)2. Through the crystal‐ and ligand‐field theory, the microscopic spin‐Hamiltonian parameters and local molecular structure for Pd(I) center in the γ‐irradiated Pd(II)(acac)2 system have been studied by using the high‐order perturbation formulas and Newman's superposition model. Based on these calculations, it was found that the distance of the metal‐ligand bonds in the square planar complex for Pd(I) center in the γ‐irradiated Pd(II)(acac)2 system increases by 0.1Å. To understand the detailed physical and chemical properties of the [Pd(I)(acac)2]2– complex, the contributions of the spin‐orbit coupling of ligand to spin‐Hamiltonian parameters for Pd(I) ion are considered. The theoretical results are in reasonable agreement with the experimental values. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxidative Stress Modulation Immediately After Hemodialysis
Authors: Alamdari Daryoush Hamidi , Honarmand Malektaj , Sarrafnejad Abdolfattah , Varasteh Abdolreza , Parizadeh Mohammad Reza , Ghayour‐Mobarhan Majid , Fahimi Daryoush , Kostidou Elena , Hatzitolios Apostolos I. , Koliakos George
Published: October 2009

AIM

The aim of this study was to estimate oxidative stress (OS) before and after dialysis in hemodialysis (HD) patients and correlate this stress with routine biochemical parameters.

METHOD

Sera of patients (n = 21), under regular HD, were collected 5 minutes before and after an HD session. Oxidative stress was estimated using the pro‐oxidant‐antioxidant assay (PAB), along with routine biochemical parameters in the same sera.

RESULTS

A significant increase of OS value was observed in HD patients 5 minutes after dialysis. Before HD, a significant correlation was established between the PAB values and fasting blood sugar, calcium, and C‐reactive protein (CRP); and an inverse correlation between the PAB values and uric acid, serum creatinine, albumin, and albumin/globulin ratio. This correlation was not obvious after HD. PAB value, after dialysis, correlated significantly only with serum iron and inversely with alanine transaminase.

CONCLUSION

This study found that the already‐increased OS in HD patients is further increased immediately after dialysis. However, factors influencing post‐dialysis OS may be different from pre‐dialysis factors.
Successful Switch to Tacrolimus in a Patient with Pseudotumor Cerebri Following Cyclosporine a Treatment in Renal Transplantation
Authors: Lee Sang Joon , Jung Yeon Soon , Rim Hark , Yoo Bong Goo
Published: October 2009

We report a case involving a 26‐year‐old Asian woman who developed pseudotumor cerebri (PTC) 2 years after renal transplantation. Cyclosporine A (CsA) was the only medication with a known neurotoxic side effect among her medications. CsA was discontinued and substituted with tacrolimus. After the CsA had been stopped, the elevated intracranial pressure gradually decreased and the bilateral papilledema finally normalized within 6 months. The case described herein is the first case of PTC that improved after renal transplantation by switching from CsA to tacrolimus.
Association of the metabolic syndrome with depression and anxiety in Japanese men: A 1‐year cohort study
Authors: Takeuchi Takeaki , Nakao Mutsuhiro , Nomura Kyoko , Inoue Mariko , Tsurugano Shinobu , Shinozaki Yasuko , Yano Eiji
Published: October 2009

Background

Recent studies on the association between the metabolic syndrome (MetS) and depression have reported conflicting findings. This 1‐year cohort study aims to evaluate the association of MetS with the development of both depression and anxiety.

Methods

The cohort comprised 956 Japanese male employees of an enterprise (mean age, 42.7 years; SD, 10.2 years). MetS was diagnosed according to the International Diabetes Federation criteria. The psychological conditions of depression and anxiety were assessed in 2 successive years by using the profile of mood states (POMS) questionnaire and by conducting clinical interviews as per the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV). We evaluated the temporal and dose‐response relationships between MetS and the development of depression and anxiety, controlling for potential confounding factors like age and lifestyle‐related factors.

Results

We identified a positive relationship between MetS at baseline and new‐onset depression in the subsequent year (OR 2.14, 95% CI 1.10–4.17). Of the five MetS components examined, only waist circumference was significantly related to new‐onset depression (OR 2.08, 1.23–3.50). Trend analysis revealed a significant positive trend of association between the number of MetS components identified and new‐onset depression (Ptrend < 0.01), but not between Mets and new‐onset anxiety.

Conclusions

Our results suggest that MetS is a predictive factor for the development of depression, and that waist circumference largely contributes to the association between MetS and depression. Copyright © 2009 John Wiley & Sons, Ltd.
Curcumin induces the tolerogenic dendritic cell that promotes differentiation of intestine‐protective regulatory T cells
Authors: Cong Yingzi , Wang Lanfang , Konrad Astrid , Schoeb Trenton , Elson Charles O.
Published: October 2009

The gut is home to a large number of Treg, with both CD4+ CD25+ Treg and bacterial antigen‐specific Tr1 cells present in normal mouse intestinal lamina propria. It has been shown recently that intestinal mucosal DC are able to induce Foxp3+ Treg through production of TGF‐β plus retinoic acid (RA). However, the factors instructing DC toward this mucosal phenotype are currently unknown. Curcumin has been shown to possess a number of biologic activities including the inhibition of NF‐κB signaling. We asked whether curcumin could modulate DC to be tolerogenic whose function could mimic mucosal DC. We report here that curcumin modulated BM‐derived DC to express ALDH1a and IL‐10. These curcumin‐treated DC induced differentiation of naïve CD4+ T cells into Treg resembling Treg in the intestine, including both CD4+CD25+ Foxp3+ Treg and IL‐10‐producing Tr1 cells. Such Treg induction required IL‐10, TGF‐β and retinoic acid produced by curcumin‐modulated DC. Cell contact as well as IL‐10 and TGF‐β production were involved in the function of such induced Treg. More importantly, these Treg inhibited antigen‐specific T‐cell activation in vitro and inhibited colitis due to antigen‐specific pathogenic T cells in vivo.
Monocyte and neutrophil recruitment during oral Salmonella infection is driven by MyD88‐derived chemokines
Authors: Rydström Anna , Wick Mary Jo
Published: October 2009

Oral Salmonella infection recruits phagocytes to Peyer's patches (PP) and MLN. The chemokines induced in infected PP and MLN, the cellular sources during infection and the TLR signaling pathways involved in vivo are not known. Here, we show that CCL2, CXCL9 and CXCL2 mRNA are up‐regulated in PP and MLN coincident with the first arrival of monocytes and neutrophils. Laser capture microdissection microscopy revealed that chemokine mRNA up‐regulation was differently distributed in PP. Despite this, recruited monocytes and neutrophils formed inflammatory cell clusters throughout PP. Monocytes and neutrophils purified from infected mice preferentially produced CXCL2 and small amounts of CCL2, and neutrophils from infected mice migrated towards CXCL2 and CCL3. Furthermore, phagocyte recruitment to PP and MLN was intact in mice lacking TLR4 alone and when signaling through TLR4 and TLR5 was simultaneously absent; however, recruitment was compromised in MyD88−/− and more so in MyD88−/−TLR4−/− double knockout mice. Phagocyte release into the blood, however, was only marginally reduced in MyD88−/−TLR4−/− mice. Defective phagocyte recruitment to PP and MLN of MyD88−/−TLR4−/− mice was paralleled by low chemokine induction. These data provide insight into the chemokines and TLR signaling pathways that orchestrate the early phagocyte response to oral Salmonella infection.
Treg suppress CTL responses upon immunization with HSP gp96
Authors: Liu Zhen , Li Xinghui , Qiu Lipeng , Zhang Xiaojun , Chen Lizhao , Cao Sheng , Wang Fusheng , Meng Songdong
Published: October 2009

HSP gp96‐based vaccines have been trialled in rodent models and, more recently, in humans. Better understanding of gp96's immunomodulatory role will help with the design of more effective strategies for treatment of cancer and infectious diseases. In this study, we monitored the activities of T cells and activation of Treg in BABL/c mice after immunization using different doses of gp96 as adjuvant. We found that co‐injection of gp96 simultaneously stimulated both CTL and Treg activity. Activation of CTL at low dose was far more pronounced than Treg activation. Treg population and suppression increased with gp96 dose, eventually abrogating the T‐cell response induced by immunization. Low‐dose cyclophosphamide treatment could restore the T‐cell responses lost after high‐dose gp96 adjuvant injection by suppression of Treg activation. We further examined the effect of different doses of gp96 or N355 peptide administration on tumor rejection. Our results provide new insights into the mechanisms of gp96‐mediated balance between regulatory and responder T cells, which may facilitate future development of an effective gp96‐based therapeutic vaccine.
Nuclear retention of IL‐1α by necrotic cells: A mechanism to dampen sterile inflammation
Authors: Luheshi Nadia M. , McColl Barry W. , Brough David
Published: October 2009

Sterile inflammation is a host response to tissue injury that is mediated by damage‐associated molecular patterns released from dead cells. Sterile inflammation worsens damage in a number of injury paradigms. The pro‐inflammatory cytokine IL‐1α is reported to be a damage‐associated molecular pattern released from dead cells, and it is known to exacerbate brain injury caused by stroke. In the brain, IL‐1α is produced by microglia, the resident brain macrophages. We found that IL‐1α is actively trafficked to the nuclei of microglia, and hence tested the hypothesis that trafficking of IL‐1α to the nucleus would inhibit its release following necrotic cell death, limiting sterile inflammation. Microglia subjected to oxygen‐glucose deprivation died via necrosis. Under these conditions, microglia expressing nuclear IL‐1α released significantly less IL‐1α than microglia with predominantly cytosolic IL‐1α. The remaining IL‐1α was immobilized in the nuclei of the dead cells. Thus, nuclear retention of IL‐1α may serve to limit inflammation following cell death.
Self‐Assembly from Two‐Dimensional Layered Networks to Tetranuclear Structures: Syntheses, Structures, and Properties of Four Copper–Thiacalix[4]arene Compounds
Authors: Bi Yanfeng , Liao Wuping , Wang Xinwu , Deng Ruiping , Zhang Hongjie
Published: October 2009

Two new copper–thiacalix[4]arene compounds, [CuI2Cl2(H4TC4A)](CH3OH) (1) and [CuI2Cl2(H4PTC4A)](CH3OH)(CHCl3)0.5 (2) (where H4TC4A = p‐tert‐butylthiacalix[4]arene and H4PTC4A = p‐phenylthiacalix[4]arene), were synthesized by the solvothermal method in the mixed CH3OH/CHCl3 (1:1) solvent and reassembled in air at room temperature to two other structures, [CuII4Cl3(HCO2)(TC4A)(CH3OH)2(H2O)](CHCl3)(CH3OH)2.7 (3) and [CuII4Cl4(PTC4A)(CH3OH)4] (4), respectively. All these four compounds were characterized by TG analyses, FTIR spectroscopy, and single‐crystal X‐ray diffraction analyses. Compounds 1 and 2 feature two‐dimensional layered networks, while compounds 3 and 4 are assembled by some tetranuclear units. The luminescence of compounds 1 and 2 in the solid state and magnetic properties of compound 3 were studied.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Genomic alterations in histopathologically normal breast tissue from BRCA1 mutation carriers may be caused by BRCA1 haploinsufficiency
Authors: Rennstam Karin , Ringberg Anita , Cunliffe Heather E. , Olsson Håkan , Landberg Göran , Hedenfalk Ingrid
Published: October 2009

Multiple biopsies of normal breast tissue from 10 BRCA1 mutation carriers have been analyzed using array‐based comparative genomic hybridization. Normal breast tissue from five age‐matched control subjects without a family history of breast cancer was included for reference purposes. We repeatedly found multiple low copy number aberrations at a significantly higher frequency in histopathologically normal tissue from BRCA1 mutation carriers than in normal control tissue. Some of these aberrations were similar across samples from different patients and linked to biological functions such as transcriptional regulation and DNA binding. We also observed a high degree of genomic heterogeneity between samples from the same patient, suggestive of tissue heterogeneity and etiological clonality in the breast epithelium. We show that neither loss of heterozygosity nor promoter methylation of the wild‐type BRCA1 allele is the predominant mechanistic origin of the observed genomic instability. Instead, we propose that haploinsufficiency of BRCA1 might be the underlying cause responsible for initiation of breast cancer in these predisposed women, making cells vulnerable to mitotic recombination. We also propose that loss of ERα expression is preceded by genetic instability in the initiation of BRCA1‐dependent tumorigenesis, indicating that the breast epithelium of BRCA1 mutation carriers may initially be estrogen‐responsive. Our results imply that genomic instability instigated by BRCA1 haploinsufficiency may be required for breast cancer initiation in BRCA1 mutation carriers. Finding molecular markers of tumor initiation and progression, for the potential use in early disease detection, may be of great clinical importance for the improved management of at‐risk women. © 2009 Wiley‐Liss, Inc.
Observed changes in streamflow at the headwaters of the Urumqi River, eastern Tianshan, central Asia
Authors: Li Zhongqin , Wang Wenbin , Zhang Mingjun , Wang Feiteng , Li Huilin
Published: October 2009

The runoff records of streams draining basins with between 0 and approximately 54% glacier cover, located at the headwaters of the Urumqi River in eastern Tianshan, central Asia, have been examined for the purpose of assessing climatic and glacial influences on temporal patterns of streamflow for the period 1959–2006. Runoff in the highest glacierized basin is found to be inversely correlated with the glacier mass‐balance data and increased by 165·1 × 104 m3 or 1·5 times on average from 1959 to 2006, whereas flow from a glacier‐free basin reflects precipitation changes associated with temperature that may enable either ground ice formation or ice storage release. For the basin with a glacier cover of 18·5%, the runoff increased approximately 355·4 × 104 m3 or 29·6% on average from 1983 to 2006, which underscores expected results based on glacier melt and precipitation increase, especially after 2000. This is due to several possible reasons including enhanced evaporation, groundwater percolation, increased water consumption due to plant colonization and runoff decrease from glacier basins subject to area reduction. From the measurement at Urumqi glacier No. 1 gauging station and a simple water balance model, the glacial runoff during the period 1959–2006 was calculated and found to have increased by 145·5 × 104 m3 a−1 (a factor of 2) over the 48‐year span. A significant amount of the increase occurred after 1987, particularly after 1995, and coincides with increases in both temperature and precipitation. Copyright © 2009 John Wiley & Sons, Ltd.
Nuclear receptors in head and neck cancer: current knowledge and perspectives
Authors: Schweitzer Andrea , Knauer Shirley K. , Stauber Roland H.
Published: October 2009

Disease management of head and neck cancer has improved significantly. However, a high rate of early recurrences and metastasis still counteract improvement of long‐term survival. Hence, the quest for molecular mechanisms and key regulatory factors exploitable by targeted therapies is still ongoing. Such potential candidates may include also nuclear receptors, belonging to a superfamily of transcription factors implicated in a broad spectrum of physiological and pathophysiological processes. As dysfunction of nuclear receptor signaling contributes to a variety of proliferative diseases, they are major targets for drug discovery and hold promising potential for the development of improved anticancer treatment strategies. Several nuclear receptors have also been associated with head and neck cancer, and strategies targeting these molecules are currently tested in clinical trials. However, reports and molecular knowledge on the pathobiological relevance of nuclear receptors for cancers of the head and neck is currently rather fragmented. Hence, this review provides a general overview of nuclear receptors' molecular functions and summarizes their potential prognostic and therapeutic relevance for this tumor entity.
Maternal folate and other vitamin supplementation during pregnancy and risk of acute lymphoblastic leukemia in the offspring
Authors: Milne Elizabeth , Royle Jill A. , Miller Margaret , Bower Carol , de Klerk Nicholas H. , Bailey Helen D. , van Bockxmeer Frank , Attia John , Scott Rodney J. , Norris Murray D. , Haber Michelle , Thompson Judith R. , Fritschi Lin , Marshall Glenn M. , Armstrong Bruce K.
Published: October 2009

The Australian Study of Causes of Acute Lymphoblastic Leukemia in Children (Aus‐ALL) was designed to test the hypothesis, raised by a previous Western Australian study, that maternal folic acid supplementation during pregnancy might reduce the risk of childhood acute lymphoblastic leukemia (ALL). Aus‐ALL was a national, population‐based, multicenter case–control study that prospectively recruited 416 cases and 1,361 controls between 2003 and 2007. Detailed information was collected about maternal use of folic acid and other vitamin supplements before and during the index pregnancy. Data were analyzed using logistic regression, adjusting for matching factors and potential confounders. A meta‐analysis with the results of previous studies of folic acid supplementation was also conducted. We found weak evidence of a protective effect of maternal folate supplementation before pregnancy against risk of childhood ALL, but no evidence for a protective effect of its use during pregnancy. A meta‐analysis including this and 2 other studies, but not the study that raised the hypothesis, also found little evidence that folate supplementation during pregnancy protects against ALL: the summary odds ratios (ORs) for folate supplementation were 1.06 [95% confidence interval (CI): 0.77–1.48] with reference to no folate supplementation and 1.02 (95% CI: 0.86–1.20) with reference to no vitamin supplementation. For vitamin supplementation in general, the summary OR from a meta‐analysis of 5 studies—including Aus‐ALL—was 0.83 (95% CI: 0.73–0.94). Vitamin supplementation in pregnancy may protect against childhood ALL, but this effect is unlikely to be large or, if real, specifically due to folate.
E‐cadherin transcriptional down‐regulation by epigenetic and microRNA‐200 family alterations is related to mesenchymal and drug‐resistant phenotypes in human breast cancer cells
Authors: Tryndyak Volodymyr P. , Beland Frederick A. , Pogribny Igor P.
Published: October 2009

The conversion of early stage tumors into invasive malignancies with an aggressive phenotype has been associated with the irreversible loss of E‐cadherin expression. The loss of E‐cadherin expression in human tumors, including breast cancer, has been attributed to promoter CpG island hypermethylation and direct inhibition by transcriptional repressors. Recent evidence demonstrates that up‐regulation of E‐cadherin by microRNA‐200b (miR‐200b) and miR‐200c through direct targeting of transcriptional repressors of E‐cadherin, ZEB1, and ZEB2, inhibits epithelial‐to‐mesenchymal transition (EMT), a crucial process in the tumor progression. We demonstrate that microRNA miR‐200 family‐mediated transcriptional up‐regulation of E‐cadherin in mesenchymal MDA‐MB‐231 and BT‐549 cells is associated directly with translational repression of ZEB1 and indirectly with increased acetylation of histone H3 at the E‐cadherin promoter. The increase in histone H3 acetylation may be attributed to the disruption of repressive complexes between ZEB1 and histone deacetylases and to the inhibition of SIRT1, a class III histone deacetylase. These events inhibit EMT and reactivate a less aggressive epithelial phenotype in cancer cells. Additionally, disruption of ZEB1‐histone deacetylase repressor complexes and down‐regulation of SIRT1 histone deacetylase up‐regulate proapoptotic genes in the p53 apoptotic pathway resulting in the increased sensitivity of cancer cells to the chemotherapeutic agent doxorubicin.
Direct‐oxidative DNA damage and apoptosis induction in different human respiratory cells exposed to low concentrations of sodium chromate
Authors: Cavallo Delia , Ursini Cinzia Lucia , Fresegna Anna Maria , Ciervo Aureliano , Maiello Raffaele , Rondinone Bruna , D'Agata Velia , Iavicoli Sergio
Published: October 2009

The mechanism of Cr(VI) genotoxicity has still not been elucidated. We used Fpg‐modified comet assay to assess direct‐oxidative DNA damage on human lung (A549) and bronchial (BEAS‐2B) cells exposed to 0.1, 0.5, 1.0 and 10 μm sodium chromate for 0.5, 1 and 4 h. Moreover we evaluated apoptosis by morphological analysis and caspase‐3 activity, also after 24 h. On A549 cells a time‐dependent DNA damage, expressed as tail DNA%, beginning from 0.5 μm was found. For oxidative DNA damage an induction after 30 min to 0.5 μm decreasing with time, and a time‐dependent increase at 10 μm was found, indicating for low Cr(VI) concentration the oxidative stress as the first event followed by direct DNA damage and for the highest concentration a time‐dependent increase in oxidative DNA damage. On BEAS‐2B cells DNA damage was induced within 1 h at 0.5–10 μm, without changes with time, showing that BEAS‐2B cells are able to resist to Cr(VI) genotoxicity. Early oxidative DNA damage at 0.1 μm decreasing with time was also found. Significant apoptosis was observed by morphological analysis in A549 cells and to a lower extent in BEAS‐2B at 10 μm. The exposure to 10 μm induced caspase‐3 activity after 4 h in BEAS‐2B and after 24 h in A549 cells. The findings show a higher responsiveness of A549 cells to genotoxic effect of Cr(VI) and early transient oxidative DNA damage in BEAS‐2B. The results emphasize the suitability of this experimental model to evaluate the early genotoxic response of different cells to non‐cytotoxic concentrations of Cr(VI) on target organ. Copyright © 2009 John Wiley & Sons, Ltd.
Metal is not inert: Role of metal ions released by biocorrosion in aseptic loosening—Current concepts
Authors: Cadosch Dieter , Chan Erwin , Gautschi Oliver P. , Filgueira Luis
Published: October 2009

Metal implants are essential therapeutic tools for the treatment of bone fractures and joint replacements. The metals and metal alloys used in contemporary orthopedic and trauma surgery are well tolerated by the majority of patients. However, complications resulting from inflammatory and immune reactions to metal implants have been well documented. This review briefly discusses the different mechanisms of metal implant corrosion in the human body, which lead to the release of significant levels of metal ions into the peri‐implant tissues and the systemic blood circulation. Additionally, this article reviews the effects of the released ions on bone metabolism and the immune system and discusses their involvement in the pathophysiological mechanisms of aseptic loosening and metal hypersensitivity in patients with metal implants. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Involvement of prostaglandins and histamine in nickel wire‐induced acute inflammation in mice
Authors: Hirasawa Noriyasu , Goi Yoshiaki , Tanaka Rina , Ishihara Kenji , Ohtsu Hiroshi , Ohuchi Kazuo
Published: October 2009

The irritancy of Nickel (Ni) ions has been well documented clinically. However, the chemical mediators involved in the acute inflammation induced by solid Ni are not fully understood. We used the Ni wire‐implantation model in mice and examined roles of prostaglandins and histamine in plasma leakage in the acute phase. The subcutaneous implantation of a Ni wire into the back of mice induced plasma leakage from 8 to 24 h and tissue necrosis around the wire at 3 days, whereas the implantation of an aluminum wire induced no such inflammatory responses. An increase in the mRNA for cyclooxygenase (COX)‐2 and HDC in cells around the Ni wire was detected 4 h after the implantation. The leakage of plasma at 8 h was inhibited by indomethacin in a dose‐dependent manner. Dexamethasone and the p38 MAP kinase inhibitor SB203580 also inhibited the exudation of plasma consistent with the inhibition of the expression of COX‐2 mRNA. Furthermore, plasma leakage was partially but siginificantly reduced in histamine H1 receptor knockout mice and histidine decarboxylase (HDC) knockout mice but not in H2 receptor knockout mice. These results suggested that the Ni ions released from the wire induced the expression of COX‐2 and HDC, resulting in an increase in vascular permeability during the acute phase of inflammation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Expression of intein‐tagged fusion protein and its applications in downstream processing
Authors: Wang Lishi , Kang Jung Hye , Kim Ki Hyung , Lee E. K.
Published: October 2009

The conventional methods of downstream purification of a recombinant protein are not only complicated and delicate but time consuming, and need to be improved. Since the intein, the protein splicing element, was discovered, this self‐cleaving element has been exploited and applied to the purification of recombinant proteins which could significantly simplify the purification procedure. Intein has the unique property that when it is combined with an affinity tag, it enables a target protein to be purified in a single chromatographic step. This review elucidates the properties of intein (the mechanism that unravels the intein‐based protein splicing), the advantages of an intein affinity expression system, the progress of intein‐based protein purification procedures, and recent advances in the applications of intein. Further development of the intein‐based purification system may lead to the applications of this system to industrial‐scale production of recombinant proteins. Copyright © 2009 Society of Chemical Industry
Enhanced biogas production from herbal‐extraction process residues by microwave‐assisted alkaline pretreatment
Authors: Cheng Xi‐Yu , Liu Chun‐Zhao
Published: October 2009

BACKGROUND: Lignocellulosic wastes such as herbal‐extraction process residues (HPR) are not easily utilized by microorganisms owing to their physical shielding of cellulose imparted by the non‐digestible lignin. Therefore, there is a great interest to develop an efficient pretreatment technique to disrupt recalcitrant structures of lignocellulosic wastes and improve renewable energy production.

RESULTS: A microwave‐assisted alkaline pretreatment (MAP) method has been developed for the enhancement of biogas production from HPR. The maximum cumulative biogas production reached 1477 mL when the HPR was hydrolyzed by MAP for 30 min with an alkali loading of 0.12 g‐NaOH/g‐HPR, where the maximum weight loss of HPR after biogas fermentation reached 72.1%.

CONCLUSION: The present work demonstrated that MAP is a promising method for improving bioconversion of lignocellulosic wastes to biogas. HPR pretreated by combining microwave irradiation and alkali resulted in releasing more soluble substances from HPR and increasing the accessibility of HPR for anaerobic biodigestion compared with traditional alkaline pretreatment (AP) and microwave‐assisted water pretreatment (MWP). Copyright © 2009 Society of Chemical Industry
Chemical and morphological features of dental composite resin: Influence of light curing units and immersion media
Authors: Dos Santos Patrícia Aleixo , Garcia Patrícia Petromilli Nordi Sasso , De Oliveira Ana Luisa Botta Martins , Chinelatti Michelle Alexandra , Palma‐Dibb Regina Guenka
Published: October 2009

Aims:

The study evaluated the influence of light curing units and immersion media on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M) through the EDX analysis and SEM evaluation. Light curing units with different power densities and mode of application used were XL 3000 (480 mW/cm2), Jet Lite 4000 Plus (1230mW/cm2), and Ultralume Led 5 (790 mW/cm2) and immersion media were artificial saliva, Coke®, tea and coffee, totaling 12 experimental groups. Specimens (10 mm × 2 mm) were immersed in each respective solution for 5 min, three times a day, during 60 days and stored in artificial saliva at 37°C ± 1°C between immersion periods. Topography and chemical analysis was qualitative.

Findings:

Groups immersed in artificial saliva, showed homogeneous degradation of matrix and deposition of calcium at the material surface. Regarding coffee, there was a reasonable chemical degradation with loss of load particles and deposition of ions. For tea, superficial degradation occurred in specific areas with deposition of calcium, carbon, potassium and phosphorus. For Coke®, excessive matrix degradation and loss of load particles with deposition of calcium, sodium, and potassium.

Conclusion:

Light curing units did not influence the superficial morphology of composite resin tested, but the immersion beverages did. Coke® affected material's surface more than did the other tested drinks. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Quantitative analysis of spatial proteoglycan content in articular cartilage with Fourier transform infrared imaging spectroscopy: Critical evaluation of analysis methods and specificity of the parameters
Authors: Rieppo L. , Saarakkala S. , Närhi T. , Holopainen J. , Lammi M. , Helminen H.J. , Jurvelin J.S. , Rieppo J.
Published: October 2009

Objective:

To evaluate the specificity of the current Fourier transform infrared imaging spectroscopy (FT‐IRIS) methods for the determination of depthwise proteoglycan (PG) content in articular cartilage (AC). In addition, curve fitting was applied to study whether the specificity of FT‐IRIS parameters for PG determination could be improved.

Methods:

Two sample groups from the steer AC were prepared for the study (n = 8 samples/group). In the first group, chondroitinase ABC enzyme was used to degrade the PGs from the superficial cartilage, while the samples in the second group served as the controls. Samples were examined with FT‐IRIS and analyzed using previously reported direct absorption spectrum techniques and multivariate methods and, in comparison, by curve fitting. Safranin O‐stained sections were measured with digital densitometry to obtain a reference for depthwise PG distribution.

Results:

Carbohydrate region‐based absorption spectrum methods showed a statistically weaker correlation with the PG reference distributions than the results of the curve fitting (subpeak located approximately at 1,060 cm−1). Furthermore, the shape of the depthwise profiles obtained using the curve fitting was more similar to the reference profiles than with the direct absorption spectrum analysis.

Conclusions:

Results suggest that the current FT‐IRIS methods for PG analysis lack the specificity for quantitative measurement of PGs in AC. The curve fitting approach demonstrated that it is possible to improve the specificity of the PG analysis. However, the findings of the present study suggest that further development of the FT‐IRIS analysis techniques is still needed. Microsc. Res. Tech. 2010. © 2009 Wiley‐Liss, Inc.
Development and neuronal dependence of cutaneous sensory nerve formations: Lessons from neurotrophins
Authors: Montaño Juan A. , Pérez‐Piñera Pablo , García‐Suárez Olivia , Cobo Juan , Vega Jose A.
Published: October 2009

Null mutations of genes from the NGF family of NTs and their receptors (NTRs) lead to loss/reduction of specific neurons in sensory ganglia; conversely, cutaneous overexpression of NTs results in skin hyperinnervation and increase or no changes in the number of sensory neurons innervating the skin. These neuronal changes are paralleled with loss of specific types of sensory nerve formations in the skin. Therefore, mice carrying mutations in NT or NTR genes represent an ideal model to identify the neuronal dependence of each type of cutaneous sensory nerve ending from a concrete subtype of sensory neuron, since the development, maintenance, and structural integrity of sensory nerve formations depend upon sensory neurons. Results obtained from these mouse strains suggest that TrkA positive neurons are connected to intraepithelial nerve fibers and other sensory nerve formations depending from C and Aδ nerve fibers; the neurons expressing TrkB and responding to BDNF and NT‐4 innervate Meissner corpuscles, a subpopulation of Merkell cells, some mechanoreceptors of the piloneural complex, and the Ruffini's corpuscles; finally, a subpopulation of neurons, which are responsive to NT‐3, support postnatal survival of some intraepithelial nerve fibers and Merkel cells in addition to the muscle mechanoreceptors. On the other hand, changes in NTs and NTRs affect the structure of non‐nervous structures of the skin and are at the basis of several cutaneous pathologies. This review is an update about the role of NTs and NTRs in the maintenance of normal cutaneous innervation and maintenance of skin integrity. Microsc. Res. Tech. 2010. © 2009 Wiley‐Liss, Inc.
Ultrastructural alterations in liver of mice exposed chronically and transgenerationally to aqueous extract of betel nut: Implications in betel nut‐induced carcinogenesis
Authors: Choudhury Yashmin , Sharan Rajeshwar N.
Published: October 2009

The aqueous extract of betel nut (AEBN) induces the formation of preneoplastic nodules in the liver of Swiss Albino mice and leads to increased predisposition to cancer when administered transgenerationally. The aim of this investigation was to elucidate the alterations in ultrastructure of subcellular organelles in the liver nodules using transmission electron microscopy and to determine whether these alterations have implications in AEBN‐induced carcinogenesis. Male and female Swiss Albino mice were exposed to AEBN chronically and transgenerationally at a dose of 2 mg/mL in drinking water for 24 weeks. Extensive polymorphism was noted in nuclear shape and heterochromatin organization. Heterochromatin aggregation and marginalization were observed in the nuclei of chronically exposed mice, whereas transgenerationally exposed mice exhibited dispersion or loss of heterochromatin. The nuclear envelope was disrupted, and the nucleoli were enlarged in chronically exposed mice, whereas in transgenerationally exposed mice the nucleoli were reduced in size or totally absent. The cisternae of the rough endoplasmic reticulum were dilated and disrupted, and a large number of autophagic vesicles were observed in both chronically and transgenerationally exposed mice. Atypical mitochondria that underwent extensive cristolysis and progressively declined in size and number from the chronically exposed mice to the different generations of transgenerationally exposed mice were also observed. Thus, exposure to AEBN resulted in severe loss of ultrastructural integrity of cells in the liver nodules, and the progressive loss of mitochondrial function appeared to play a significant role in increasing the predisposition to cancer of mice exposed transgenerationally to AEBN. Microsc. Res. Tech. 2010. © 2009 Wiley‐Liss, Inc.
Structure characterization of lipocyclopeptide antibiotics, aspartocins A, B & C, by ESI‐MSMS and ESI‐nozzle‐skimmer‐MSMS
Authors: Siegel Marshall M. , Kong Fangming , Feng Xidong , Carter Guy T.
Published: October 2009

Three lipocyclopeptide antibiotics, aspartocins A (1), B (2), and C (3), were obtained from the aspartocin complex by HPLC separation methodology. Their structures were elucidated using previously published chemical degradation results coupled with spectroscopic studies including ESI‐MS, ESI‐Nozzle Skimmer‐MSMS and NMR. All three aspartocin compounds share the same cyclic decapeptide core of cyclo [Dab2 (Asp1‐FA)‐Pip3‐MeAsp4‐Asp5‐Gly6‐Asp7‐Gly8‐Dab9‐Val10‐Pro11]. They differ only in the fatty acid side chain moiety (FA) corresponding to (Z)‐13‐methyltetradec‐3‐ene‐carbonyl, (+,Z)‐12‐methyltetradec‐3‐ene‐carbonyl and (Z)‐12‐methyltridec‐3‐ene‐carbonyl for aspartocins A (1), B (2), and C (3), respectively. All of the sequence ions were observed by ESI‐MSMS of the doubly charged parent ions. However, a number of the sequence ions observed were of low abundance. To fully sequence the lipocyclopeptide antibiotic structures, these low abundance sequence ions together with complementary sequence ions were confirmed by ESI‐Nozzle‐Skimmer‐MSMS of the singly charged linear peptide parent fragment ions H‐Asp5‐Gly6‐Asp7‐Gly8‐Dab9‐Val10‐Pro11‐Dab21+‐Asp1‐FA. Cyclization of the aspartocins was demonstrated to occur via the β‐amino group of Dab2 from ions of moderate intensity in the ESI‐MSMS spectra. As the fatty acid moieties do not undergo internal fragmentations under the experimental ESI mass spectral conditions used, the 14 Da mass difference between the fatty acid moieties of aspartocins A (1) and B (2) versus aspartocin C (3) was used as an internal mass tag to differentiate fragment ions containing fatty acid moieties and those not containing the fatty acid moieties. The most numerous and abundant fragment ions observed in the tandem mass spectra are due to the cleavage of the tertiary nitrogen amide of the pipecolic acid residue‐3 (16 fragment ions) and the proline residue‐11 (7 fragment ions). In addition, the neutral loss of ethanimine from α,β‐diaminobutyric acid residue 9 was observed for the parent molecular ion and for 7 fragment ions. Copyright © 2009 John Wiley & Sons, Ltd.
Trans‐hemispheric effects of large volcanic eruptions as recorded by an early 19th century diary
Authors: Lee D. S. , MacKenzie A. R.
Published: October 2009

An early 19th century diary, belonging to a farmer from NW England, contains detailed daily weather entries over a 15‐year period from 1815 to 1829. The diary period encompasses the Tambora volcanic eruption and pre‐dates the establishment of routine meteorological observations. The diary entries were imported into a database and the descriptive entries categorised and transformed into ordinal data for statistical analysis, measuring frequencies of weather events or related phenomena. In ranked comparisons, the diary is strongly correlated with established temperature and precipitation datasets, providing confidence in the reliability of the diary as a data source. From the categorised diary data, significant indicators of poor climate are identified, including higher‐than‐mean occurrences of low pressure, summer cold and rainfall. The years 1817, 1816 and 1823, respectively have the highest number of indicators of poor weather with high or very high significance, totalling 21 over these 3 years, whereas only 11 are recorded in total for the remaining 10 years of data. Thus significant climate anomalies are found in the 2 years following the Tambora 1815 eruption and to a lesser extent 1 year following another major eruption, Galunggung in 1822. As well as colder and wetter summers, other indicators such as optical phenomena, which are not routinely included in climate records, are recorded. There is no evidence that the diarist was aware of the Tambora and Galunggung eruptions at the time of writing. Although the diary covers a relatively short time span and is largely qualitative in nature, it is from an early period, pre‐dating the establishment of the UK Meteorological Office, and is unusually methodical. The diary contains a wealth of data which could be further exploited. The current study demonstrates the potential of database technology for categorising and quantifying descriptive data sources in historical climate studies. Copyright © 2009 Royal Meteorological Society