bluuebunny/crossref_metadata_2025 huggingface dataset:
Zinc(II), Copper(II), and Nickel(II) Complexes of Bis(tripodal) Diamide Ligands – Reversible Switching of the Amide Coordination Mode upon Deprotonation
Authors: Hahn F. Ekkehardt , Schröder Henning , Pape Tania , Hupka Florian
Published: January 2010

A series of dinuclear Zn(II), Cu(II) and Ni(II) complexes of two new bis‐tripodal ligands with aromatic (H2‐4a) and aliphatic (H2‐4b) diamide spacers has been synthesized and structurally characterized. Each of the two tripodal entities of the neutral dinucleating ligands coordinates to one metal ion via three amine functions and a carbonyl oxygen atom of the amide groups. Either trifluoroacetate counterions or solvent molecules complete the trigonal‐bipyramidal (Zn, 5a), square‐pyramidal (Cu, 6a and 6b), and octahedral (Ni, 7a and 7b) coordination environment at the metal centers. Complexes 5a, 6a, and 7a with the phenylene‐bridged diamide ligand are readily deprotonated by potassium tert‐butoxide effecting a rearrangement of the dinuclear complexes. In the resulting zinc and copper complexes 8 and 9, one of the metal centers is coordinated by three amine functions of a tripodal subunit and the two amidate nitrogen atoms of the deprotonated ligand 4a2– while the coordination geometry of the second metal atom remains unchanged. The analogous nickel compound crystallizes as neutral tetranuclear complex (10)2 with intermolecular coordination of two amide carbonyl oxygen atoms to the nickel atoms of an adjacent dinuclear complex. The resulting coordination mode with binding of all four donor functions of the diamide spacer to three discrete metal centers is to date unprecedented for ortho‐phenylene‐bridged acetamides. The rearrangement upon deprotonation has been shown to be fully reversible and the starting complexes can be retrieved upon protonation of the two amidate functions. Synthesis of the trinuclear zinc complex 11 with coordination of the two amidate nitrogen atoms to a third metal center was achieved via deprotonation of (H6‐4a)(CF3CO2)4 by three equivalents of diethylzinc. In protic solvents 11 rapidly rearranges to give the entropically favored dinuclear complex 8 with elimination of one equivalent of zinc trifluoroacetate.
Ordering Phenomena in Complex Chalcogenides – the Showcase of A2In12Q19 (A = K, Tl, NH4; Q = Se, Te) and Pseudobinary In2Q3 (Eur. J. Inorg. Chem. 3/2010)
Authors: Kienle Lorenz , Schlosser Marc , Manos Manolis J. , Malliakas Christos D. , Duppel Viola , Reiner Christof , Deiseroth Hans‐Jörg , Kanatzidis Mercouri G. , Kelm Klemens , Simon Arndt
Published: January 2010

The cover picture shows the structural complexity of the A2In12Q19 phases, which was unravelled by a combined methodical approach including state‐of‐the‐art XRD and HRTEM techniques (background). An ordered arrangement of the atoms is limited to nanodomains built from the extended structural fragments (foreground) that constitute these crystalline solids as a whole. Details are discussed in the article by H.‐J. Deiseroth et al. on p. 367 ff.
Di‐ and Trifluorobenzenes in Reactions with Me2EM (E = P, N; M = SiMe3, SnMe3, Li) Reagents: Evidence for a Concerted Mechanism of Aromatic Nucleophilic Substitution
Authors: Goryunov Leonid I. , Grobe Joseph , Le Van Duc , Shteingarts Vitalij D. , Mews Rüdiger , Lork Enno , Würthwein Ernst‐Ulrich
Published: January 2010

Dimethyl(trimethylsilyl)phosphane (Me3SiPMe2) has been successfully used for the substitution of fluorine variously in 1,3‐ (1) or 1,2‐difluorobenzene (2) or in 1,3,5‐ (3) or 1,2,3‐trifluorobenzene (4) by the Me2P group at 150–190 °C either in benzene solution or without solvent to give 1‐(dimethylphosphanyl)‐3‐fluorobenzene (5) from 1, 1‐(dimethylphosphanyl)‐2‐fluorobenzene (6) from 2, 1‐(dimethylphosphanyl)‐3,5‐difluorobenzene (7) from 3 or a 1:1 mixture of 1‐(dimethylphosphanyl)‐2,3‐difluorobenzene (8) and 1‐(dimethylphosphanyl)‐2,6‐difluorobenzene (9) from 4. The substrate selectivities and regioselectivities exhibited by 4 with Me3SiPMe2 and in competitive reactions between 1 and 2 or 3 and 4 with Me2PSiMe3, Me2PSnMe3 or Me2PLi indicate relative fluorine substituent rate factors fo‐F > fm‐F, whereas for reactions that proceed through a two‐step SNAr mechanism the opposite sequence is typical. High‐level quantum‐chemical DFT and MP2 calculations predict that the gas‐phase reactions should each proceed by a concerted mechanism with a single transition state. These predictions are in good agreement with the experimental observations, especially because the structural features of the Meisenheimer adduct are unfavourable for the SNAr mechanism. This proposal is consistent with the observation of the opposite sequence (fm‐F > fo‐F) for the reactions between the same substrates and MeONa in DMSO/CH3OH solvent mixtures. The novel phosphanes were characterized by spectroscopic (NMR) and spectrometric (MS) investigation, preparation of the thiophosphanes ArFPSMe2 10–12, their spectroscopic data and, in the case of 12, by its X‐ray structure. The phosphanes 5–9 were treated with bis(benzonitrile)dichloropalladium(II) to afford the corresponding bis(phosphane)palladium dichloride complexes 17–21 and 23 in isolated yields of up to 95 %.
A nBuLi‐Mediated, Expeditious and Stereoselective Ring‐Opening Rearrangement of (Arylmethylene)cyclopropane‐1,1‐dicarboxylates
Authors: Hu Bao , Jiang Linan , Ren Jun , Wang Zhongwen
Published: January 2010

We report herein an nBuLi‐mediated, expeditious, ring‐opening rearrangement of (arylmethylene)cyclopropane 1,1‐diesters to prepare 1,3‐diene derivatives with good stereoselectivity. The reaction mechanism has also been discussed.
A 2D Layered Chiral Supramolecular Organic Fluorophore Composed of 1‐Amino‐2‐indanol and Carboxylic Acid Derivatives
Authors: Imai Yoshitane , Shiota Naoki , Kinuta Takafumi , Okuno Takahiro , Nakano Yoko , Harada Takunori , Sato Tomohiro , Fujiki Michiya , Kuroda Reiko , Matsubara Yoshio
Published: January 2010

A chiral anthracenecarboxylic acid/amine supramolecular organic fluorophore composed of a 2D layered network structure was developed by combining 1‐amino‐2‐indanol and 2‐anthracenecarboxylic acid molecules. This 2D, chiral fluorophore exhibits circularly polarized luminescence (CPL) without quenching the fluorescence in the solid state.
Synthesis of 3‐Methylenecyclohexan‐1‐ols by Lewis Acid Catalyzed Cyclization of (Epoxy–allyl)silanes
Authors: Pulido Francisco J. , Barbero Asunción , Castreño Pilar
Published: January 2010

A new route for the synthesis of (epoxy–allyl)silanes bearing the PhMe2Si group has been developed and their acid‐catalyzed cyclization studied. The so‐called normal products derived from 5‐exo or 6‐endo attack were never obtained. On the contrary, an interesting tandem rearrangement/cyclization process was observed, which selectively led to 3‐methylenecyclohexan‐1‐ols. A mechanism is proposed to explain this tandem reaction. The stereoselectivity of the cyclization process depends on the nature of the catalyst.
Fabrication of New Magnetic Nanoparticles (Fe3O4) Grafted Multiwall Carbon Nanotubes and Heterocyclic Compound Modified Electrode for Electrochemical Sensor
Authors: Huang Hui , Liu Xingmei , Zhang Xueyu , Liu Weilu , Su Xingguang , Zhang Zhiquan
Published: January 2010

Magnetic Fe3O4 nanoparticles functionalized multiwalled carbon nanotubes (nano‐Fe3O4 MWNTs) were prepared for electrochemical sensors. 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole was used as a connecter to form a network that connected nano‐Fe3O4 MWNTs to the Au electrode surface. Modified process of the electrode was studied with SEM, TEM and cyclic voltammetry. Cyclic voltammetry and amperometric i‐t curve were used to investigate characteristics of the obtained electrode. The sensor has been successfully used on the direct detection of catechol and showed excellent performances. The linear regression equation was Ipa(μA)=0.07763+0.16739 C (μmol/L); R=0.9993 and the detection limit was 5.38×10−8 mol/L. The modified electrode showed good reproducibility and stability.
Novel Nanoporous Binary AuRu Electrocatalysts for Glucose Oxidation
Authors: Yi Qingfeng , Yu Wenqiang , Niu Fengjuan
Published: January 2010

In this work, we study the fabrication, structural characterization, and electrochemical activity of titanium‐supported binary AuRu catalysts for glucose oxidation. The catalysts including Au99Ru1, Au95Ru5, Au93Ru7 and Au88Ru12 were prepared by a hydrothermal method using formaldehyde as a reduction agent. The morphologies of the prepared AuRu catalyst structures are characterized by porous dendritic particles with roughened surfaces with nano‐sized flakes. Electrochemical catalytic activity of the binary AuRu catalysts towards glucose oxidation in alkaline solutions was investigated using cyclic voltammetry and chronoamperometry. All binary AuRu catalysts facilitate glucose oxidation at the lower potentials and deliver higher anodic oxidation currents compared to pure Au catalyst. Among them, the binary Au95Ru5 catalyst presents the most negative onset potential of −0.872 V (vs. Ag/AgCl, 3 M KCl) for glucose oxidation in 0.1 M NaOH solution. For the Au95Ru5 catalyst, chronoamperometric data at the potential step of −0.65 V (vs. Ag/AgCl,3 M KCl) exhibit a well linear dependence of the anodic oxidation current density on glucose concentration in the range of 0 to 15 mM glucose.
Optimal boundary discretization by variational data assimilation
Authors: Kazantsev Eugene
Published: January 2010

A variational data assimilation technique applied to the identification of the optimal discretization of interpolation operators and derivatives in the nodes adjacent to the boundary of the domain is discussed in frames of the linear shallow water model. The advantage of controlling the discretization of operators near the boundary rather than boundary conditions is shown. Assimilating data that have been produced by the same model on a finer grid, in a model on a coarse grid, we have shown that optimal discretization allows us to correct such errors of the numerical scheme as under‐resolved boundary layer and wrong wave velocity. Copyright © 2010 John Wiley & Sons, Ltd.
A direct numerical simulation of axisymmetric liquid–gas two‐phase laminar flows in a pipe
Authors: Tai Cheng‐Feng , Chung J. N.
Published: January 2010

An accurate finite‐volume‐based numerical method for the simulation of an isothermal two‐phase flow, consisting of a liquid slug translating in a non‐reacting gas in a circular pipe is presented. This method is built on a sharp interface concept and developed on an Eulerian Cartesian fixed‐grid with a cut‐cell scheme and marker points to track the moving interface. The unsteady, axisymmetric Navier–Stokes equations in both liquid and gas phases are solved separately. The mass continuity and momentum flux conditions are explicitly matched at the true surface phase boundary to determine the interface shape and movement. A quadratic curve fitting algorithm with marker points is used to yield smooth and accurate information of the interface curvatures.

It is uniquely demonstrated for the first time with the current method that conservation of mass is strictly enforced for continuous infusion of flow into the domain of computation. The method has been used to compute the velocity and pressure fields and the deformation of the liquid core. It is also shown that the current method is capable of producing accurate results for a wide range of Reynolds number, Re, Weber number, We, and large property jumps at the interface. Copyright © 2010 John Wiley & Sons, Ltd.
Occurrence of depression and its correlates in early onset dementia patients
Authors: Rosness Tor Atle , Barca Maria Lage , Engedal Knut
Published: January 2010

Objective

We wanted to investigate the occurrence of depression in early onset dementia (EOD) patients and which characteristics were associated with depressive symptoms.

Methods

We included 221 patients who were diagnosed with dementia before the age of 65. Depression in these patients was measured by the Montgomery Asberg depression scale (MADRS). Measurements of cognition, behavioural and psychological symptoms and activities of daily life were along with hypothyroidism, diabetes and stroke included in the analysis. History of depression, current psychiatric co‐morbidity and usage of antidepressants were recorded.

Results

Mean age of patients was 58.6 years (SD = 5.2); 50.6% were women. Of them 123 patients (55.6%) had a mild degree of depression (MADRS total score 7–19), 21 patients (9.5%) had a moderate degree of depression (MADRS total score 20–34) and only 1 patient had a severe degree of depression (MADRS total score ≥35). A factor analysis produced two factors; the first factor described dysphoria: lack of concentration, pessimistic thoughts, inner tension, suicidal thoughts lassitude and lack of sleep. The second factor denoted sadness: observed sadness, reported sadness, lack of appetite and inability to feel. In an adjusted linear regression analysis history of depression was the only significantly variable associated with the MADRS total score and both factors 1 and 2.

Conclusion

We found a high occurrence of depressive symptoms in EOD patients; 65.7% of all our patients had some degree of depression. A history of depression was the most important correlate of depression in these patients. Copyright © 2010 John Wiley & Sons, Ltd.
Assessing mild cognitive impairment among older African Americans
Authors: Gamaldo Alyssa A. , Allaire Jason C. , Sims Regina C. , Whitfield Keith E.
Published: January 2010

Objectives

To examine the frequency of Mild Cognitive Impairment (MCI) in African American older adults. The study also plans to explore the specific cognitive domains of impairment as well as whether there are differences in demographics, health, and cognitive performance between MCI and normal participants.

Design

Cross‐sectional.

Setting

Independent‐living sample of urban dwelling elders in Baltimore, Maryland.

Participants

The sample consisted of 554 subjects ranging in age from 50 to 95 (Mean = 68.79 ± 9.60).

Measurements

Socio‐demographics and health were assessed. Several cognitive measures were administered to assess inductive reasoning, declarative memory, perceptual speed, working memory, executive functioning, language and global cognitive functioning.

Results

Approximately 22% of participants were considered MCI (i.e. 18% non‐amnestic vs. 4% amnestic). A majority of the non‐amnestic MCI participants had impairment in one cognitive domain, particularly language and executive function. Individuals classified as non‐amnestic MCI were significantly older and had more years of education than normal individuals. The MCI groups were not significantly different than cognitively normal individuals on health factors. Individuals classified as MCI performed significantly worse on global cognitive measures as well as across specific cognitive domains than cognitively normal individuals.

Conclusion

This study demonstrates that impairment in a non‐memory domain may be an early indicator of cognitive impairment, particularly among African Americans. Copyright © 2010 John Wiley & Sons, Ltd.
Stereoselective synthesis and antioxidant activity of azabicycloadducts derived from 9,10‐phenanthrenequinone
Authors: Arora Komal , Jose D. , Singh D. , Gupta R. S. , Pardasani P. , Pardasani R. T.
Published: January 2010

A facile synthesis of sprio{1‐aza‐bicyclo‐[3,3,0]‐6‐octene‐8,1′ ‐phenanthrene}‐2′‐ones has been accomplished by [3+2] cycloaddition of azomethine ylide (amy) generated from 9,10‐phenanthrenequinone and different secondary cyclic amino acids, namely, thiazolidine‐4‐carboxylic acid, L‐pyrrolidine‐2‐carboxylic acid (L‐proline), and piperidine‐2‐carboxylic acid (pipecolinic acid) with electron‐deficient dipolarophiles in 67%–79% yield. AM1 calculations have been performed to understand the stereochemical course of the cycloaddition. The products have been characterized by elemental analyses and spectroscopic techniques, namely IR, 1H NMR, and 13C NMR spectroscopies as well as mass spectrometry. Some of the synthesized cycloadducts showed moderate antioxidant activity. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:379–392, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20562
Reversibility of metabolic and morphological changes associated with chronic exposure of pancreatic islet β‐cells to fatty acids
Authors: Pinnick Katherine , Neville Matt , Clark Anne , Fielding Barbara
Published: January 2010

Pancreatic β‐cells metabolise both lipid and glucose nutrients but chronic exposure (>24 h) to elevated fatty acid (FA) concentrations results in deleterious metabolic and morphological changes. The aims of this study were to assess the adaptive morphological, metabolic and secretory responses of islet β‐cells to exposure and removal of FA. Isolated mouse islets and INS‐1 β‐cells were exposed to oleate or palmitate (0.5 mM) or a 1:1 mixture of both FA for 48 h prior to a 24 h period without FA. Subsequent changes in lipid storage and composition (triglycerides, TG and phospholipids, PL), gene expression, β‐cell morphology and glucose‐stimulated insulin secretion (GSIS) were determined. Intracellular TG content increased during exposure to FA and was lower in cells subsequently incubated in FA‐free media (P < 0.05); TG storage was visible as oil red O positive droplets (oleate) by light microscopy or ‘splits’ (palmitate) by electron microscopy. Significant desaturation of β‐cell FA occurred after exposure to oleate and palmitate. After incubation in FA‐free media, there was differential handling of specific FA in TG, resulting in a profile that tended to revert to that of control cells. FA treatment resulted in elevated lipolysis of intracellular TG, increased FA oxidation and reduced GSIS. After incubation in FA‐free media, oxidation remained elevated but inhibition of FA oxidation with etomoxir (10 µM) had no effect on the improvement in GSIS. The β‐cell demonstrates metabolic flexibility as an adaptive response to ambient concentrations of FA. J. Cell. Biochem. 109: 683–692, 2010. © 2010 Wiley‐Liss, Inc.
Keratinocyte growth factor promotes preadipocyte proliferation via an autocrine mechanism
Authors: Zhang Ting , Guan Haiyan , Yang Kaiping
Published: January 2010

Keratinocyte growth factor (KGF; also known as FGF‐7) is a well‐characterized paracrine growth factor for tissue growth and regeneration. However, its role in adipose tissue, which is known to undergo tremendous expansion in obesity, is virtually unknown. Given that we previously identified KGF as one of the up‐regulated growth factors in adipose tissue of an early‐life programmed rat model of visceral obesity, the present study was undertaken to examine the hypothesis that KGF promotes adipogenesis. Using 3T3‐L1 and rat primary preadipocytes as in vitro model systems, we demonstrated that (1) KGF stimulated preadipocyte proliferation in a concentration‐dependent manner with a maximal effect at 2.5 ng/ml (∼2‐fold increase); (2) KGF mRNA was highly expressed in rat adipocytes and preadipocytes as well as 3T3‐L1 cells; (3) treatment of preadipocytes with a neutralizing antibody against KGF and siRNA‐mediated knockdown of KGF led to a 50% reduction in their proliferative capacity; (4) KGF activated the protein kinase Akt, and the PI3 kinase inhibitor LY294002 blocked KGF stimulation of preadipocyte proliferation; and (5) KGF did not promote differentiation of preadipocytes to mature adipocytes. Together, these results reveal adipocytes and their precursor cells as novel sites of KGF production. Importantly, they also demonstrate that KGF promotes preadipocyte proliferation by an autocrine mechanism that involves activation of the PI3K/Akt signaling pathway. Aberrant KGF expression may have consequences not only for normal adipose tissue growth but also for the pathogenesis of obesity. J. Cell. Biochem. 109: 737–746, 2010. © 2010 Wiley‐Liss, Inc.
Hormone and pharmaceutical regulation of ASP production in 3T3‐L1 adipocytes
Authors: Gao Ying , Gauvreau Danny , Cianflone Katherine
Published: January 2010

Several studies have demonstrated increases in acylation stimulating protein (ASP), and precursor protein C3 in obesity, diabetes and dyslipidemia, however the nature of the regulation is unknown. To evaluate chronic hormonal and pharmaceutical mediated changes in ASP and potential mechanisms, 3T3‐L1 adipocytes were treated with physiological concentrations of relevant hormones and drugs currently used in treatment of metabolic diseases for 48 h. Medium ASP production and C3 secretion were evaluated in relation to changes in adipocyte lipid metabolism (cellular triglyceride (TG) mass, non‐esterified fatty acid (NEFA) release and real‐time FA uptake). Chylomicrons increased ASP production (up to 411 ± 133% P < 0.05), while leptin, triiodothyronine, and β‐blockers atenolol and propranolol had no effect. Dexamethasone, lovastatin, rosiglitazone and rimonabant decreased ASP production (−53 to −85%, P < 0.05), associated with a decrease in the precursor protein C3 (−37% to −65%, P < 0.01). By contrast, epinephrine, progesterone, testosterone, angiotensin II and metformin also decreased ASP (−54% to −100%, P < 0.05), but without change in precursor protein C3, suggesting a direct effect on convertase activity, possibly mediated by interference (except metformin) due to marked increases in NEFA (5.6–31‐fold, increased P < 0.05). Both lovastatin and metformin induced decreases in ASP were also associated with decreased TG mass (maximal −60%, P < 0.05) and real‐time FA uptake (maximum −75%, P < 0.05), suggesting a change in adipocyte differentiation status. These in vitro results are consistent with in vivo ASP profiles in subjects, and suggest that ASP may be regulated through precursor C3 availability, convertase activity and differentiation status. J. Cell. Biochem. 109: 896–905, 2010. © 2010 Wiley‐Liss, Inc.
Cyclic strain modulates migration and proliferation of vascular smooth muscle cells via Rho‐GDIα, Rac1, and p38 pathway
Authors: Qi Ying‐Xin , Qu Ming‐Juan , Yan Zhi‐Qiang , Zhao Dan , Jiang Xiao‐Hua , Shen Bao‐Rong , Jiang Zong‐Lai
Published: January 2010

Cyclic strain is an important inducer of proliferation and migration of vascular smooth muscle cells (VSMCs) which are involved in vascular remodeling during hypertension. However, its mechanism remains to be elucidated. VSMCs of rat aorta were exposed to cyclic strains in vitro with defined parameters, the static, 5%‐strain (physiological) and 15%‐strain (pathological), at 1.25 Hz for 24 h respectively. Then the possible signaling molecules participated in strain‐induced VSMC migration and proliferation were investigated. The results showed that 15%‐strain significantly increased VSMC migration and proliferation in comparison with 5%‐strain. Expression of Rho GDP dissociation inhibitor alpha (Rho‐GDIα) was repressed by 15%‐strain, but expressions of phospho‐Rac1 and phospho‐p38 were increased. Expressions of phospho‐Akt and phospho‐ERK1/2 were similar between the static, 5%‐strain and 15%‐strain groups. Rho‐GDIα “knock‐down” by target siRNA transfection increased migration and proliferation of VSMCs, and up‐regulated phosphorylation of Rac1 and p38 in all groups. Rac1 “knock‐down” repressed migration and proliferation of VSMCs, down‐regulated phosphorylation of p38, but had no effect on Rho‐GDIα expression. When siRNAs of Rho‐GDIα and Rac1 were co‐transfected to VSMCs, the expressions of Rho‐GDIα and phospho‐Rac1 were both decreased, and the effects of Rho‐GDIα “knock‐down” were blocked. Rho‐GDIα “knock‐down” promoted while Rac1 “knock‐down” postponed the assembly of stress fibers and focal adhesions in static. The results demonstrate that the pathological cyclic strain might induce migration and proliferation of VSMCs via repressing expression of Rho‐GDIα, which subsequently verified phosphorylations of Rac1 and p38. J. Cell. Biochem. 109: 906–914, 2010. © 2010 Wiley‐Liss, Inc.
SUV39h‐ and A‐type lamin‐dependent telomere nuclear rearrangement
Authors: Uhlířová Radka , Horáková Andrea Harničarová , Galiová Gabriela , Legartová Soňa , Matula Pavel , Fojtová Miloslava , Vařecha Miroslav , Amrichová Jana , Vondráček Jan , Kozubek Stanislav , Bártová Eva
Published: January 2010

Telomeres are specialized chromatin structures that are situated at the end of linear chromosomes and play an important role in cell senescence and immortalization. Here, we investigated whether changes in histone signature influence the nuclear arrangement and positioning of telomeres. Analysis of mouse embryonic fibroblasts revealed that telomeres were organized into specific clusters that partially associated with centromeric clusters. This nuclear arrangement was influenced by deficiency of the histone methyltransferase SUV39h, LMNA deficiency, and the histone deacetylase inhibitor Trichostatin A (TSA). Similarly, nuclear radial distributions of telomeric clusters were preferentially influenced by TSA, which caused relocation of telomeres closer to the nuclear center. Telomeres also co‐localized with promyelocytic leukemia bodies (PML). This association was increased by SUV39h deficiency and decreased by LMNA deficiency. These differences could be explained by differing levels of the telomerase subunit, TERT, in SUV39h‐ and LMNA‐deficient fibroblasts. Taken together, our data show that SUV39h and A‐type lamins likely play a key role in telomere maintenance and telomere nuclear architecture. J. Cell. Biochem. 109: 915–926, 2010. © 2010 Wiley‐Liss, Inc.
Trihydrophobin 1 attenuates androgen signal transduction through promoting androgen receptor degradation
Authors: Yang Yanzhong , Zou Weiying , Kong Xiangfei , Wang Hanzhou , Zong Hongliang , Jiang Jianhai , Wang Yanlin , Hong Yi , Chi Yayun , Xie Jianhui , Gu Jianxin
Published: January 2010

The androgen‐signaling pathway plays critical roles in normal prostate development, benign prostatic hyperplasia, established prostate cancer, and in prostate carcinogenesis. In this study, we report that trihydrophobin 1 (TH1) is a potent negative regulator to attenuate the androgen signal‐transduction cascade through promoting androgen receptor (AR) degradation. TH1 interacts with AR both in vitro and in vivo, decreases the stability of AR, and promotes AR ubiquitination in a ligand‐independent manner. TH1 also associates with AR at the active androgen‐responsive prostate‐specific antigen (PSA) promoter in the nucleus of LNCaP cells. Decrease of endogenous AR protein by TH1 interferes with androgen‐induced luciferase reporter expression and reduces endogenous PSA expression. Taken together, these results indicate that TH1 is a novel regulator to control the duration and magnitude of androgen signal transduction and might be directly involved in androgen‐related developmental, physiological, and pathological processes. J. Cell. Biochem. 109: 1013–1024, 2010. © 2010 Wiley‐Liss, Inc.
PSMD9 is linked to MODY3
Authors: Gragnoli Claudia
Published: January 2010

Type 2 diabetes has a replicated linkage on chromosome12q24.2 (NIDDM2 locus/non‐insulin‐dependent diabetes mellitus 2 locus), near the HNF‐1α/MODY3 gene. The MODY3 gene is not responsible for this linkage. PSMD9—contributing to T2D in Italians by rare unique mutations and by the common haplotype A/T/G—lies in the NIDDM2 region. By genotyping the two markers D12S1721/D12S2073 nearby the MODY3 gene in our unrelated T2D cases, we previously excluded that the PSMD9 SNPs are in linkage disequilibrium (LD) with the MODY3 gene. In the present study, we aimed at identifying whether the PSMD9 A/T/G haplotype is present in the Italy‐1 and Italy‐3 MODY3 families and whether it cosegregates with diabetes/MODY3. We raised the question whether there is a digenic additive model within the MODY3 families to which the PSMD9 A/T/G haplotype contributes. We demonstrated that the PSMD9 A/T/G haplotype is linked to the MODY3 established mutations in the Italy‐1 and Italy‐3 families. By non‐parametric and parametric linkage analyses, and LD modeling, in the Italy‐1 and Italy‐3 families we hereby show that the MODY3 mutation and the PSMD9 IVS3 + nt460A/IVS3 + nt437T/G197 SNPs act in an additional model to cause diabetes. Since in the two MODY3 Italian families the PSMD9 A/T/G haplotype is linked to MODY3, it contributes to MODY3/diabetes via an additional model. All MODY3 families should be tested for the PSMD9 A/T/G haplotype. The potential clinical impact of our study is of relevance. J. Cell. Physiol. 223: 1–5, 2010. © 2010 Wiley‐Liss, Inc.
Batch biodegradation of hydrocarbon vapors using a modified polymeric support
Authors: Gutiérrez‐Acosta Olga B , Escobar‐Barrios Vladimir A , Arriaga Sonia
Published: January 2010

BACKGROUND: One of the major problems facing biofilter operation is the long start‐up periods, which is related to microbial adhesion in packing materials among other factors. In order to deal with this limitation, modifying a hydrophobic polymer with an additive containing hydroxyl groups was proposed to improve the water retention capacity of the material in the biodegradation of a mixture of hydrocarbon vapors in batch tests.

RESULTS: The synthesized material with 40% by weight of hydroxyl‐containing additive had a water retention capacity of 34%. The presence of hydroxyl groups was confirmed by absorbance at 1100 cm−1 wave number using Fourier transform infrared spectroscopy analysis. Complete biodegradation of methyl ethyl ketone and toluene vapors were achieved on the sixth day whereas hexane vapors were degraded on the 14th day. The time required for the complete biodegradation of hydrocarbons with the modified polymer was at least 30% lower than that obtained with the non‐modified polymer.

CONCLUSIONS: The additive, a hydrocarbon containing hydroxyl groups, was able to modify the polymer's hydrophilic character. In addition, the additive improved the microbial growth and the attachment of microorganisms to the material; thus, it enhanced the biodegradation rates of hydrocarbon vapors. This makes the composite suitable for application as a packing material for biofilters. Copyright © 2010 Society of Chemical Industry
Silicone oil: An effective absorbent for the removal of hydrophobic volatile organic compounds
Authors: Darracq Guillaume , Couvert Annabelle , Couriol Catherine , Amrane Abdeltif , Thomas Diane , Dumont Eric , Andres Yves , Le Cloirec Pierre
Published: January 2010

BACKGROUND: Hydrophobic volatile organic compounds (VOCs), such as toluene, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), are poorly soluble in water and classical air treatment processes like chemical scrubbers are not efficient. An alternative technique involving an absorption step in an organic solvent followed by a biodegradation phase was proposed. The solvent must fulfil several characteristics, which are key factors of process efficiency, and a previous study allowed polydimethylsiloxane (or PDMS, i.e. silicone oil) to be selected for this purpose. The aim of this paper was to determine some of its characteristics like absorption capacity and velocity performances (Henry's constant, diffusivity and mass transfer coefficient), and to verify its non‐biodegradability.

RESULTS: For the three targeted VOCs, Henry's constants in silicone oil were very low compared to those in water, and solubility was infinite. Diffusivity values were found to be in the range 10−10 to 10−11 m2 s−1 and mass transfer coefficients did not show significant differences between the values in pure water and pure silicone oil, in the range 1.0 × 10−3 to 4.0 × 10−3 s−1 for all the VOCs considered. Silicone oil was also found to be non‐biodegradable, since its biological oxygen demand (BOD5) value was zero.

CONCLUSION: Absorption performances of silicone oil towards toluene, DMS and DMDS were determined and showed that this solvent could be used during the first step of the process. Moreover, its low biodegradability and its absence of toxicity justify its use as an absorbent phase for the integrated process being considered. Copyright © 2010 Society of Chemical Industry
Oxidation of biologically produced elemental sulfur under neutrophilic conditions
Authors: Fortuny Marc , Guisasola Albert , Casas Carles , Gamisans Xavier , Lafuente Javier , Gabriel David
Published: January 2010

BACKGROUND: Previous research on a biotrickling filter for the removal of high loads of H2S showed that accumulation of elemental sulfur (S0) when dealing with high H2S concentrations could lead to reactor clogging. Since S0 can also serve as substrate for sulfur‐oxidising bacteria, this study investigates the biological oxidation of S0 as a remediation strategy.

RESULTS: Results indicated that biological oxidation of S0 inside a clogged biotrickling filter occurred at a comparable rate to those reported for stirred tank reactors. When biologically produced dried and powdered S0 was manually added as a substrate in stirred tank reactor experiments, significantly lower S0 oxidation rates were found compared to those for biological S0 freshly produced in situ. It was speculated that either the powdered S0 particle size or the surface properties hindered S0 bioavailability even in a well‐stirred environment. Respirometric experiments with the same powdered S0 and acetone‐dissolved S0 confirmed that biological oxidation of S0 was basically limited by the solid S0 bioavailability.

CONCLUSIONS: Therefore, results showed that S0 oxidation basically depends on S0 bioavailability and that Sulfate volumetric production rates as high as 3.48 mmol SO42− h−1 L−1 can be achieved inside a clogged biotrickling filter probably due to the high biomass retention capacity. Overall, the results indicate that biological oxidation of S0 can be considered a suitable strategy for unclogging bioreactors clogged with S0. Copyright © 2010 Society of Chemical Industry
Evaluation of innovative packing materials for the biodegradation of H2S: a comparative study
Authors: Dumont Eric , Andrès Yves
Published: January 2010

The biofiltration of gas polluted with H2S was carried out using innovative configurations of packing materials (i.e. a new synthetic material called UP20, sapwood, peat, pozzolan and pine bark). A comparison of seven different configurations (media alone or in combination) was made based on biofilter performances and pressure drop measurements. Biofilters were operated continuously for at least 95 days at a constant flow rate (0.5 N m3 h−1 corresponding to a superficial velocity of 65 m h−1 and an empty bed residence time of 57 s). Elimination capacities and removal efficiencies were calculated according to loading rates varying from 0 to 25.5 g m−3 h−1 (inlet concentration up to 400 mg m−3). Biofilter performances were modelled and biokinetic constants were calculated using the Ottengraf model and a modified Michaelis–Menten model. In terms of elimination capacity, packing materials can be ordered from the most efficient to the least efficient: peat–UP20 in a mixture > peat–UP20 in two layers > peat > pozzolan–UP20 in two layers > pine bark > sapwood–UP20 in two layers > sapwood. A maximal removal rate, Vm, of 55 g m−3 h−1 was calculated for biofilters filled with peat–UP20 (in a mixture or in two layers) and peat (in comparison, Vm = 8.3 g m−3 h−1 for a biofilter filled with sapwood). Peat is the best material to treat high H2S concentrations and the addition of UP20 can significantly increase the removal efficiency. The pozzolan–UP20 combination represents an interesting packing material to treat pollutant loading rates up to 5 g m−3 h−1 with low pressure drops. For low H2S concentrations, sapwood can be considered as a good support for H2S degradation with pollutant loading rates up to 4 g m−3 h−1. Copyright © 2010 Society of Chemical Industry
Interaction of compounds on biodegradation of ketone mixtures in a biofilter
Authors: Chan Wu‐Chung , Lai Tzu‐Yu
Published: January 2010

BACKGROUND: Acetone and methyl ethyl ketone (MEK) are commonly mixed together in the effluent streams from the manufacturing of semiconductors and optics–electronics. The metabolic activity on the biodegradation of two or more pollutants may involve induction, inhibition or co‐metabolism, depending on the substrates and microbial species present. The compound interaction on the biochemical kinetic behaviours of an acetone and MEK mixture in a composite bead biofilter was investigated.

RESULTS: The microbial growth rate and biochemical reaction rate of the two biodegraded compounds was inhibited and the inhibitive effect resulting from increasing the compound inlet concentration predominated at a higher compound inlet concentration for the single compound system. The microbial metabolic activity of biodegraded acetone in the microbial growth process and biochemical reaction process was inhibited as MEK was introduced and the inhibitive effect resulting from interaction of the compounds was more pronounced at higher MEK inlet concentrations and lower acetone inlet concentrations for the two compounds mixing system. The maximum elimination capacity of acetone and MEK for the two compounds mixing system was smaller and greater than those for the single compound system, respectively.

CONCLUSION: The biodegradation rate of acetone in a biofilter would be inhibited as MEK was introduced. Copyright © 2010 Society of Chemical Industry
Effect of silicone oil fraction and stirring rate on methane degradation in a stirred tank reactor
Authors: Rocha‐Rios José , Muñoz Raúl , Revah Sergio
Published: January 2010

BACKGROUND: Methane is an important greenhouse gas and its biological oxidation constitutes a cost‐effective alternative for low concentration emissions. Nevertheless, due to its low aqueous solubility (similar to oxygen), gas mass transfer is often the limiting step. Two‐phase partition bioreactors (TPPBs), have been proposed to increase the biodegradation of poorly soluble compounds. In this work, the effect of stirring rate and silicone oil fraction on abiotic volumetric oxygen transfer coefficient kLa and methane elimination capacity (EC) by a methanotrophic consortium in a stirred tank was studied.

RESULTS: In abiotic conditions, the kLa increased when increasing both factors. Nevertheless, a negative effect on kLa was observed with silicone oil at the highest stirring rate (800 rpm). During methane biodegradation experiments, EC also improved when increasing both factors, but contrary to abiotic kLa, it was not affected at the highest stirring rate. While stirring rate was the dominant variable determining methane biodegradation, the effect of oil fraction was only significant above 200 rpm. A maximum EC improvement of 700% was observed when increasing stirring rate from 200 to 800 rpm with 10% of silicone oil.

CONCLUSIONS: Increasing both stirring rate and oil fraction enhanced EC. The results were different from those observed with kLa suggesting that kLa is not sufficient to describe properly the mass transfer in TPPB because other factors (interfacial contact between the phases and physicochemical properties of organic phase) should be considered. Copyright © 2010 Society of Chemical Industry
Modeling of a hollow fiber membrane biofilm reactor for nitric oxide removal: model development and experimental validation
Authors: Kumar Amit , Ergas Sarina J. , Yuan Xin , Fitch Mark , Min Kyung‐Nan , Dewulf Jo , Van Langenhove Herman
Published: January 2010

BACKGROUND: A diffusion and reaction model was developed for a hollow fiber membrane biofilm reactor (MBfR) to control nitric oxide (NO) emissions. In the MBfR, waste gases containing biodegradable compounds pass through the lumen of microporous hydrophobic hollow fiber membranes. Soluble, biodegradable compounds diffuse through the membrane pores and partition into a biofilm attached to the membranes where they are biodegraded. The membranes serve as a support for the microbial population and provide a large surface area for mass transfer. A dynamic model was developed for the MBfR which assumed biodegradation via Monod kinetics and constant biofilm thickness and density. The model was validated using experimental data from a study of NO removal (100 ppm) from a combustion gas mixture in a bench‐scale MBfR with an acclimatized nitrifying population.

RESULTS: NO gas was treated in a bench‐scale MBfR at varying liquid recirculation velocities of 0.8 to 2.0 cm s−1. The gas residence time (τ), calculated as the membrane lumen volume divided by the gas flow rate, was 1.9 s. NO removal efficiency for synthetic combustion gas ranged between 68% and 73% at room temperature (20 °C).

CONCLUSION: The MBfR shows promise for treatment of waste gases from combustion processes. The model predicted an optimal liquid recirculation velocity of 1.5 cm s−1 for NO removal, which is in good agreement with experimental data. Sensitivity experiments with the numeric model indicated that removal was a strong function of the biofilm density and the Monod maximum specific growth rate (µmax). Copyright © 2010 Society of Chemical Industry
Effect of drying and calcination on the toluene combustion activity of a monolithic CuMnAg/γAl2O3/cordierite catalyst
Authors: Wu Dongfang , Jiang Wei , Zhou Jiancheng
Published: January 2010

BACKGROUND: This paper presents a mathematical modeling and factorial analysis of the toluene combustion activity of a cordierite monolith supported copper–manganese–silver mixed‐oxide catalyst in the drying and calcination processes, using response surface methodology. A central composite rotatable design is performed to collectively study the effect of drying temperature, calcination temperature and calcination time. Experimental results are provided to confirm the validity of the models developed.

RESULTS: The calcination temperature is the most significant process factor affecting the catalytic combustion activity. It is also shown that the combustion activity increases in most cases with decreasing calcination time and that a moderate calcination or drying temperature is required to increase the combustion activity. The optimal factor levels are drying temperature 160 °C, calcination temperature 500 °C, and calcination time 3 h.

CONCLUSIONS: There is significant scope to improve the combustion activity of the monolithic catalyst through the optimization of the drying and calcination process factors. Response surface methodology is an effective technique for mathematical modeling and factorial analysis of the catalytic activity of monolithic catalysts. Copyright © 2010 Society of Chemical Industry
Labelling of the guanylate cyclase activator cinaciguat (BAY 58‐2667) with carbon‐14, tritium and stable isotopes
Authors: Seidel D. , Pleiß U.
Published: January 2010

For studies of pharmacokinetics and drug metabolism of the new soluble guanylate cyclase activator cinaciguat (BAY 58‐2667) the 14C‐labelled compound was synthesized. The tritiated compound was required to elucidate the mode of action and the stable labelled compound was required for bio‐analytical studies by quantitative mass spectrometry as well. Two radiosyntheses are described with different formation of the labelled intermediate 1‐(chloro[14C]methyl)‐4‐(2‐phenylethyl)benzene. The first one started with 14C‐carboxylation of 1‐bromo‐4‐(2‐phenylethyl)benzene yielding the desired product in 5 steps. In the second synthesis intermediate 1‐(chloro[14C]methyl)‐4‐(2‐phenylethyl)benzene was formed by chloromethylation of bibenzyl with [14C]paraformaldehyde/hydrochloric acid subsequently resulting in the final product in three steps. Tritium labelling was performed by tritium exchange of the diester intermediate using an organo‐iridium catalyst and subsequent saponification. The stable labelled compound was synthesized via a convergent synthesis starting with 13C,15N‐cyanation of 1‐(chloromethyl)‐2‐{[4‐(2‐phenylethyl)benzyl]oxy}benzene and 13C‐cyanation of methyl 4‐bromobenzoate, respectively. The labelled product was obtained after 7 chemical steps. Copyright © 2010 John Wiley & Sons, Ltd.
Nocturnal Cool Island in the Sahelian city of Ouagadougou, Burkina Faso
Authors: Lindén Jenny
Published: January 2010

Relatively little is known about the urban climate processes of the fastest growing cities in the world today. Described in this paper are urban–rural and intra‐urban variations in air temperature and humidity in one of these cities; Ouagadougou, Burkina Faso. Measurements were collected from car traverses and fixed site measurements during two field studies. The aim of the study was to determine the influence of land use on the urban climate in this hot‐dry region, with a focus on the role of vegetation and of a large centrally located reservoir.

Analyses of results show that vegetation is the most important factor in the nocturnal urban climate in Ouagadougou, while effects of built up and paved areas are limited. Average urban–rural temperature differences demonstrate that while the evening urban heat island (UHI) reached only 1.9 °C, the cool island in a densely vegetated area was 5.0 °C cooler than the dry rural reference. Temperature differences of the same magnitude persisted throughout the night between vegetated and non‐vegetated areas, regardless of urban or rural setting. Cooling from the open water of the reservoir was the most important parameter during daytime, while during evenings and nights, direct effects of the open water of the reservoir are very limited, and the availability of water, allowing enhanced vegetation cover, is of much greater importance compared to the water itself.

The results presented here show that the urban land cover, together with climatic region, can create significant differences in the physical properties driving the urban climate in a dry‐tropical city compared to those commonly found in temperate cities. Copyright © 2010 Royal Meteorological Society
In vitro inhibition of aggrecanase activity by tetracyclines and proteoglycan loss from osteoarthritic human articular cartilage
Authors: Steinmeyer Jürgen , Kordelle Jens , Stürz Henning
Published: January 2010

Tetracyclines were reported to slow down the progression of cartilage damage both in an animal model of osteoarthritis (OA) and in humans. In search for the underlying mechanisms we examined whether tetracyclines possess an inhibitory potential on the activity of aggrecanases and inflammatory mediators and can thus prevent proteoglycan (PG) loss from human articular cartilage. In vitro activity of aggrecanase‐1 and ‐2 was recorded in the presence of 1–100 µM tetracycline, minocycline, or doxycyline. Human knee articular cartilage explants were sorted according to the degree of OA and treated for 10 days with tetracycline derivatives in the presence of interleukin‐1 (IL‐1β). Synthesis and loss of PGs, nitric oxide (NO), and prostaglandin E2 (PGE2), as well as the viability were determined. Tetracyclines derivatives dose‐dependently inhibited the activities of both aggrecanases in vitro, whereas no inhibitory effect of tetracyclines on any proteoglycanolytic activities within IL‐1β‐treated human cartilage explants were found. Tetracyclines can significantly modulate NO and PGE2 levels, but have no effect on PG synthesis and loss within the same human cartilage explant cultures. Altogether, our data show that tetracyclines have no inhibitory potential on any proteoglycanolytic activities within mild or moderately affected human OA cartilage at therapeutic achievable plasma levels. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:828–833, 2010