bluuebunny/crossref_metadata_2025 huggingface dataset:
Two New Cytotoxic Candidaspongiolides from an Indonesian Sponge
Authors: Trianto Agus , Hermawan Idam , Suzuka Toshimasa , Tanaka Junichi
Published: July 2011

Marine sponges have been recognized as potentially rich sources of various bioactive molecules. In our continuing search for new secondary metabolites from Indonesian marine invertebrates, we collected a sponge, whose extract showed cytotoxicity against cultured cells at 0.1 μg/mL. Purification of the extract yielded two new macrolides 2 and 3 along with known candidaspongiolide (1). The structures for compounds 2 and 3 were elucidated by spectral analysis (H1, C13, COSY, HMQC, HMBC) and by comparison of their NMR data with those of 1. Compounds 2 and 3 exhibited a little more potent cytotoxicity (IC50 4.7 and 19 ng/mL) than that (IC50 37 ng/mL) of candidaspongiolide (1) against NBT-T2 cells.
Chemical Coupling of Carbon Nanotubes and Silicon Nanoparticles for Improved Negative Electrode Performance in Lithium‐Ion Batteries
Authors: Martin Cédric , Crosnier Olivier , Retoux Richard , Bélanger Daniel , Schleich Donald M. , Brousse Thierry
Published: July 2011

Multi‐walled carbon nanotube (MWCNT)/silicon nanocomposites obtained by a grafting technique using the diazonium chemistry are used to prepare silicon negative electrodes for lithium‐ion batteries. The covalent bonding of the two compounds is obtained via mono‐ and multi‐layers of phenyl bridges, leading to an ideal dispersion of MWCNTs and silicon nanoparticles that are bound together. The presence of MWCNTs close to silicon nanoparticles enhances the electronic pathway to the active material particles and probably helps to prevent silicon decrepitation upon repeated lithium insertion/extraction by improving the mechanical stability of the electrode at a nanoscale level. This effect results in the enhancement of cycling ability and capacity, which are demonstrated by comparing the nanocomposite electrode to a simple mixture of the two compounds. This technique can be applied to other carbon conductive additives together with silicon or other nanosized active compounds.
Very Low Degree of Energetic Disorder as the Origin of High Mobility in an n‐channel Polymer Semiconductor
Authors: Caironi Mario , Bird Matt , Fazzi Daniele , Chen Zhihua , Di Pietro Riccardo , Newman Christopher , Facchetti Antonio , Sirringhaus Henning
Published: July 2011

Charge transport is investigated in high‐mobility n‐channel organic field‐effect transistors (OFETs) based on poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (P(NDI2OD‐T2), Polyera ActivInk™ N2200) with variable‐temperature electrical measurements and charge‐modulation spectroscopy. Results indicate an unusually uniform energetic landscape of sites for charge‐carrier transport along the channel of the transistor as the main reason for the observed high‐electron mobility. Consistent with a lateral field‐independent transport at temperatures down to 10 K, the reorganization energy is proposed to play an important role in determining the activation energy for the mobility. Quantum chemical calculations, which show an efficient electronic coupling between adjacent units and a reorganization energy of a few hundred meV, are consistent with these findings.
Anointing variation across wild capuchin populations: a review of material preferences, bout frequency and anointing sociality in Cebus and Sapajus
Authors: Alfaro Jessica W. Lynch , Matthews Luke , Boyette Adam H. , Macfarlan Shane J. , Phillips Kimberley A. , Falótico Tiago , Ottoni Eduardo , Verderane Michele , Izar Patrícia , Schulte Meredith , Melin Amanda , Fedigan Linda , Janson Charles , Alfaro Michael E.
Published: July 2011

The frequency of anointing bouts and the materials used for self‐ and social anointing vary across capuchin species in captivity, but there is little published data on capuchin anointing in the wild. Here we present previously unpublished data on anointing behaviors from capuchin monkey populations at ten different field sites and incorporate these data into a review of the anointing literature for captive and wild capuchins. Using a comparative phylogenetic framework, we test four hypotheses derived primarily from captive literature for variation in anointing between wild untufted capuchins (Cebus) and tufted capuchins (Sapajus), including that (1) the frequency of anointing is higher in Cebus, (2) Cebus uses a higher proportion of plant species to insect species for anointing compared with Sapajus, (3) anointing material diversity is higher in Cebus, and (4) social indices of anointing are higher in Cebus. We found that wild Cebus anoints more with plant parts, including fruits, whereas wild Sapajus anoints more with ants and other arthropods. Cebus capucinus in particular uses more plant species per site for anointing compared with other capuchins and may specialize in anointing as an activity independent from foraging, whereas most other capuchin species tend to eat the substances they use for anointing. In agreement with captive studies, we found evidence that wild Cebus anoints at a significantly higher frequency than Sapajus. However, contrary to the captive literature, we found no difference in the range of sociality for anointing between Cebus and Sapajus in the wild. We review anointing in the context of other Neotropical primate rubbing behaviors and consider the evidence for anointing as self‐medication; as a mechanism for enhanced sociality; and as a behavioral response to chemical stimuli. Am. J. Primatol. 74:299–314, 2012. © 2011 Wiley Periodicals, Inc.
Bacterial pathogens of acute sinusitis in the osteomeatal complex during common colds and wellness
Authors: Han Joseph K. , Hendley J. Owen , Winther Birgit
Published: July 2011

Background:

Pathogenic bacteria have been cultured from the osteomeatal complex (OMC) in one‐third of adults with apparent acute bacterial sinusitis; however, it is not known whether bacteria are present in the OMC during uncomplicated viral colds in adults.

Methods:

Adult volunteers were recruited for a study during wellness and at the time of acute common cold. Swab cultures were obtained from the OMC and from the nasopharynx by 2 routes (through the nose and through the mouth). Swab eluates were inoculated on selective agars to detect S. pneumoniae, H. influenzae, and M. catarrhalis.

Results:

Bacterial pathogens were detected in the OMC more frequently during common colds than during wellness (31% vs 8%, p < 0.008). Pathogens detected in the OMC were always present in the nasopharynx of the subject.

Conclusion:

Bacterial pathogens are present in the OMC in a subgroup of adult patients with uncomplicated upper respiratory illness/common cold. The nasopharynx appears to be the reservoir for bacterial pathogens in the OMC. © 2011 ARS‐AAOA, LLC.
Intraarticular injection of platelet‐rich plasma reduces inflammation in a pig model of rheumatoid arthritis of the knee joint
Authors: Lippross Sebastian , Moeller Bjoern , Haas Holger , Tohidnezhad Mersedeh , Steubesand Nadine , Wruck Christoph Jan , Kurz Bodo , Seekamp Andreas , Pufe Thomas , Varoga Deike
Published: July 2011

Objective

Treatment options for rheumatoid arthritis range from symptomatic approaches to modern molecular interventions such as inhibition of inflammatory mediators. Inhibition of inflammation by platelet‐rich plasma (PRP) has been proposed as a treatment for tendinitis and osteoarthritis. The present study was undertaken to investigate the effect of PRP on antigen‐induced arthritis (AIA) of the knee joint in a large animal model.

Methods

Six‐month‐old pigs (n = 10) were systemically immunized by bovine serum albumin (BSA) injection, and arthritis was induced by intraarticular BSA injection. PRP was injected into the knee joints of 5 of the animals after 2 weeks. An additional 5 animals received no systemic immunization (controls). Signs of arthritis were documented by plain histologic analysis, Safranin O staining, and immunohistochemistry analysis for type II collagen (CII), interleukin‐6 (IL‐6), and vascular endothelial growth factor (VEGF). Interleukin‐1β (IL‐1β), IL‐6, tumor necrosis factor α (TNFα), VEGF, and insulin‐like growth factor 1 (IGF‐1) protein content was measured by Luminex assay.

Results

In the pigs with AIA, plain histologic analysis revealed severe arthritic changes in the synovium. Safranin O and CII staining showed decreased proteoglycan and CII content in cartilage. Immunohistochemistry analysis revealed increased levels of IL‐6 and VEGF in synovium and cartilage, and protein concentrations of IL‐6, VEGF, IL‐1β, and IGF‐1 in synovium and cartilage were elevated as well; in addition, TNFα protein was increased in cartilage. Treatment with PRP led to attenuation of these arthritic changes in the synovium and cartilage.

Conclusion

We have described a porcine model of AIA. Experiments using this model demonstrated that PRP can attenuate arthritic changes as assessed histologically and based on protein synthesis of typical inflammatory mediators in the synovial membrane and cartilage.
A description of congenital anomalies among infants in Entebbe, Uganda
Authors: Ndibazza Juliet , Lule Swaib , Nampijja Margaret , Mpairwe Harriet , Oduru Gloria , Kiggundu Molly , Akello Miriam , Muhangi Lawrence , Elliott Alison M.
Published: July 2011

BACKGROUND: Data on congenital anomalies from developing countries of the sub‐Saharan region are scarce. However, it is important to have comprehensive and reliable data on the description and prevalence of congenital anomalies to allow surveillance and the implementation of appropriate public health strategies for prevention and management. In this study, we describe the profile of congenital anomalies seen in a birth cohort in Entebbe, Uganda. METHODS: Congenital anomalies were defined as any structural defect present at birth. Pregnant women were recruited to the cohort between 2003 and 2005. Defects present at birth were recorded by the midwife at delivery and by physicians at the routine six‐week postnatal visit and at illness‐related visits until 1 year of life. The anomalies were classified by organ system according to the 10th version of the World Health Organization International Classification of Diseases (ICD‐10). RESULTS: There were 180 infants with a congenital anomaly among 2365 births. The most commonly affected systems were the musculoskeletal (42.7 per 1000 births) and skin (16.1 per 1000 births). The prevalence of major anomalies was 20.3 per 1000 births; 1.7 per 1000 births for cardiac anomalies and 1.3 per 1000 births for neural system anomalies. Forty (22%) of the congenital anomalies were identified at birth, 131 (73%) at the 6‐week postnatal visit, and nine (5%) at illness‐related visits. CONCLUSION: Congenital anomalies are common in developing countries. Establishment of comprehensive databases for surveillance would be helpful for surveillance of effects of new exposures, for prevention, management, and health care planning. Birth Defects Research (Part A) 2011. © 2011 Wiley‐Liss, Inc.
Evaluation of developmental toxicity induced by anticholinesterase insecticide, diazinon in female rats
Authors: ElMazoudy Reda H. , Attia Azza A. , AbdElGawad Horeya S.
Published: July 2011

Developmental toxicities, including birth defects, are significant public health problems. This study was planned to assess the cholinergic and developmental potentials of diazinon that is widely used as an organophosphate insecticide. Pregnant female Sprague‐Dawley rats were given diazinon orally at doses of 0, 1.9, 3.8, and 7.6 mg/kg body weight (b.w.)/day on gestation days 6 to 15. Maternal brain acetylcholinesterase activities, measured on gestation day20, were significantly decreased at 3.8 and 7.6 mg/kg b.w./day, but fetal acetylcholinesterase activity was not altered. Maternal toxicities, as evidenced by cholinergic symptoms including diarrhea, tremors, weakness, salivation, and decreased activities, were observed at the 3.8 and 7.6 mg/kg b.w./day dose groups. Net gravid uterine weight was decreased at a dose of 7.6 mg/kg b.w./day. No maternal effects were apparent in the 1.9 mg/kg b.w./day dose group. Maternal toxicity at a dose of 3.8 mg/kg b.w./day did not induce fetotoxicity or teratogeneicity. However, 7.6 mg/kg b.w./day doses significantly resulted in fetal toxicity and malformations in addition to maternal toxicity in animals. In conclusion, teratogenic disorders only outlined by doses that produced marked maternal toxicity. Since the malformations were not morphologically related, they were considered to be secondary to maternal toxicity; hence, the malformations were not related to cholinesterase inhibition. Birth Defects Res (Part B) 92:534–542, 2011. © 2011 Wiley Periodicals, Inc.
Comparison of complex permittivities of isotonic colloids containing single‐wall carbon nanotubes of varying chirality
Authors: Nair Tejas , Symanowski James T. , Gach H. Michael
Published: July 2011

The application of bio‐compatible, conductive nanoparticles in combination with radiofrequency (RF) irradiation to raise tissue temperatures between 40 and 60 °C for hyperthermia and ablation spurred interest in the complex permittivities of isotonic nanoparticle‐based colloids. Nanoparticles with large aspect ratios and high permittivities increase the bulk permittivity of the colloid and RF losses at the macroscopic scale. The complex permittivities of isotonic colloids with and without single‐wall carbon nanotubes (SWCNTs) containing either metallic, semiconducting, or mixed chiralities were measured from 20 MHz to 1 GHz at room temperature. The colloids were made with one of three different isotonic solvents: phosphate buffered saline (PBS), and Dulbecco's modified eagle medium (DMEM) with and without 0.5% weight/volume bovine serum albumin to simulate cytosol and blood, respectively. The concentration of elemental carbon from the SWCNTs in the colloids ranged from 16 to 17 mM. The permittivities were corrected for electrode polarization effects by fitting the data to the Cole–Cole relaxation model with a constant phase angle element. The presence of SWCNTs increased both the real and imaginary components of the permittivities of the colloids. For all three solvents, the direct current (DC) components of the real and imaginary permittivities were greatest for the colloids containing the mixed chirality SWCNTs, followed by the colloids with semiconducting SWCNTs, and then metallic SWCNTs. Bioelectromagnetics 33:134–146, 2012. © 2011 Wiley Periodicals, Inc.
Photosynthetic efficiency of Chlamydomonas reinhardtii in flashing light
Authors: Vejrazka Carsten , Janssen Marcel , Streefland Mathieu , Wijffels René H.
Published: July 2011

Efficient light to biomass conversion in photobioreactors is crucial for economically feasible microalgae production processes. It has been suggested that photosynthesis is enhanced in short light path photobioreactors by mixing‐induced flashing light regimes. In this study, photosynthetic efficiency and growth of the green microalga Chlamydomonas reinhardtii were measured using LED light to simulate light/dark cycles ranging from 5 to 100 Hz at a light‐dark ratio of 0.1 and a flash intensity of 1000 µmol m−2 s−1. Light flashing at 100 Hz yielded the same photosynthetic efficiency and specific growth rate as cultivation under continuous illumination with the same time‐averaged light intensity (i.e., 100 µmol m−2 s−1). The efficiency and growth rate decreased with decreasing flash frequency. Even at 5 Hz flashing, the rate of linear electron transport during the flash was still 2.5 times higher than during maximal growth under continuous light, suggesting storage of reducing equivalents during the flash which are available during the dark period. In this way the dark reaction of photosynthesis can continue during the dark time of a light/dark cycle. Understanding photosynthetic growth in dynamic light regimes is crucial for model development to predict microalgal photobioreactor productivities. Biotechnol. Bioeng. 2011;108: 2905–2913. © 2011 Wiley Periodicals, Inc.
The Role of Attachment in Immigrant Sociocultural Adaptation and Psychological Distress
Authors: Sochos Antigonos , Diniz Marcio
Published: July 2011

The study extends recent research on the link between attachment security and the sociocultural and psychological adaptation of immigrants. It was hypothesised that attachment style would moderate the effects of sociocultural adaptation difficulties on psychological distress and the relationship between attachment style and immigrant background variables was explored. The study was correlational and questionnaire‐based, including a sample of 172 Brazilian immigrants living in the UK. According to the findings, secure and dismissing attachment styles moderated the effects of sociocultural adaptation difficulties on psychological distress. Preoccupied attachment style moderated the effects of previous immigration experience on psychological distress and the effects of duration of stay in the UK on concerns over terrorism. Future studies should employ longitudinal designs and include a variety of immigrant groups. Copyright © 2011 John Wiley & Sons, Ltd.
Phenol Group in Pyridoxamine Acts as a Stabilizing Element for Its Carbinolamines and Schiff Bases
Authors: Caldés Catalina , Vilanova Bartolomé , Adrover Miquel , Muñoz Francisco , Donoso Josefa
Published: July 2011

Pyridoxamine (PM), a natural derivative of vitamin B6, possesses a high biological and biomedical significance by virtue of its acting as enzyme cofactor in amino acid metabolism and as inhibitor in the nonenzymatic glycation of proteins. Both types of processes require the initial formation of a Schiff base. In this work, we used NMR spectroscopy to study the formation mechanism for a Schiff base between PM and formaldehyde (FA). This allowed the Schiff base and an intermediate carbinolamine (CA) to be detected. The Schiff base was found to be in isomeric equilibrium with a hemiaminal (HE) form. The formation equilibrium constants for the CA and HE over the pD range of 6.0–13.0 were determined and compared with those for the reaction between 4‐picolylamine (PAM) and formaldehyde (FA). The comparison revealed a strong influence of the phenol group on the equilibrium constant. Based on the results, the phenol group in PM is a key structural element towards stabilizing the resulting carbinolamine and Schiff base.
Phytoremediation of heavy metal‐contaminated water and sediment by Eleocharis acicularis
Authors: Sakakibara Masayuki , Ohmori Yuko , Ha Nguyen Thi Hoang , Sano Sakae , Sera Koichiro
Published: July 2011

Phytoremediation is an environmental remediation technique that takes advantage of plant physiology and metabolism. The unique property of heavy metal hyperaccumulation by the macrophyte Eleocharis acicularis is of great significance in the phytoremediation of water and sediments contaminated by heavy metals at mine sites. In this study, a field cultivation experiment was performed to examine the applicability of E. acicularis to the remediation of water contaminated by heavy metals. The highest concentrations of heavy metals in the shoots of E. acicularis were 20 200 mg Cu/kg, 14 200 mg Zn/kg, 1740 mg As/kg, 894 mg Pb/kg, and 239 mg Cd/kg. The concentrations of Cu, Zn, As, Cd, and Pb in the shoots correlate with their concentrations in the soil in a log‐linear fashion. The bioconcentration factor for these elements decreases log‐linearly with increasing concentration in the soil. The results indicate the ability of E. acicularis to hyperaccumulate Cu, Zn, As, and Cd under natural conditions, making it a good candidate species for the phytoremediation of water contaminated by heavy metals.
Synthesis of 2‐(1‐Phenylvinyl)benzofurans and 2‐(1‐Phenylvinyl)indoles as Antimitotic Agents by a Tandem Palladium‐Assisted Coupling‐Cyclization Reaction between 1‐Phenylvinyl Iodides and ortho‐Substituted Arylalkynes
Authors: Tréguier Bret , Rasolofonjatovo Evelia , Hamze Abdallah , Provot Olivier , Wdzieczak‐Bakala Joanna , Dubois Joëlle , Brion Jean‐Daniel , Alami Mouad
Published: July 2011

A series of functionalized 2‐(1‐phenylvinyl)benzofurans 2 and 2‐(1‐phenylvinyl)indoles 3 were prepared from 1‐phenylvinyl iodides and silylated alkynes in a one‐pot reaction. After a desilylation step, the Sonogashira coupling reaction between the resulting terminal alkynes and 1‐phenylvinyliodide derivatives 6 gave enyne intermediates, which underwent a 5‐endo‐dig cyclization to afford 2‐(1‐phenylvinyl) heterocycles 2 and 3 in good yields. This method provides a rapid and efficient approach to build up benzoheterocycle‐based isocombretastatin A‐4 analogues of biological interest. From this series of compounds, the indoles 3o and 3r inhibited tubulin assembly at a micromolar level comparable to that of isoCA‐4.
Confirmation that SNPs in the high mobility group‐A2 gene (HMGA2) are associated with adult height in the Japanese population; wide‐ranging population survey of height‐related SNPs in HMGA2
Authors: Takeshita Haruo , Fujihara Junko , Soejima Mikiko , Koda Yoshiro , Kimura‐Kataoka Kaori , Ono Rei‐Ichiro , Yuasa Isao , Iida Reiko , Ueki Misuzu , Nagao Masataka , Yasuda Toshihiro
Published: July 2011

Adult height is a highly heritable trait in that multiple genes are involved. Recent genome‐wide association studies have identified a novel single‐nucleotide polymorphism (SNP) rs1042725 in the high mobility group‐A2 gene (HMGA2) and shown it to be associated with human height in Caucasian populations. We performed a replication study to examine the associations between SNPs in HMGA2 and adult height in the Japanese population based on autopsy cases. Although we could not confirm a significant association between rs1042725 in HMGA2 and adult height, another SNP, rs7968902, in the gene achieved significance for its association in the same populations, and the effect was the same as that documented previously. These findings permit us to conclude that the SNPs in HMGA2 are common variants influencing human height across different populations. Moreover, a worldwide population study of these SNPs using 14 different populations including Asians, Africans and Caucasians demonstrated that both haplotypes and genotypes for three height‐related SNPs (rs1042725, rs7968682 and rs7968902) in HMGA2 were distributed in an ethnicity‐dependent manner. This information will be useful for clarifying the genetic basis of human height.
Functional and structural correlates of the aging brain: Relating visual cortex (V1) gamma band responses to age‐related structural change
Authors: Gaetz William , Roberts Timothy P.L. , Singh Krish D. , Muthukumaraswamy Suresh D.
Published: July 2011

The gamma band response is thought to be a key neural signature of information processing in the mammalian brain, yet little is known about how age‐related maturation influences the γ‐band response. Recent MRI‐based studies have shown that brain maturation is accompanied by clear structural changes in both gray and white matter, yet the correspondence of these changes to brain function is unclear. The objective of this study was to relate visual cortex (V1) γ‐band responses to age‐related structural change. We evaluated MEG measured γ‐band responses to contrast gratings stimuli and structural MRIs from participants observed from two separate research centers (MEG lab at CUBRIC, Cardiff University, UK, and the Lurie Family Foundations MEG Imaging Center, (CHOP) at the Children's Hospital of Philadelphia). Pooled participant data (N = 59) ranged in age from 8.7 to 45.3 years. We assessed linear associations between age and MEG γ‐band frequency and amplitude, as well as between age and MRI volumetric parameters of the occipital lobe. Our MEG findings revealed a significant negative correlation for gamma band frequency versus age. Volumetric brain analysis from the occipital lobe also revealed significant negative correlations between age and the cortical thickness of pericalcarine and cuneus areas. Our functional MEG and structural MRI findings shows regionally specific changes due to maturation and may thus be informative for understanding physiological processes of neural development, maturation, and age‐related decline. In addition, this study represents (to our knowledge), the first published demonstration of multicenter data sharing across MEG centers. Hum Brain Mapp 33:2035–2046, 2012. © 2011 Wiley Periodicals, Inc.
A Novel, One‐Pot Four‐Component Route to 2′‐Thioxo‐2′,3′‐dihydrospiro[indole‐3,6′‐[1,3]thiazin]‐2‐one Derivatives
Authors: Alizadeh Abdolali , Mokhtari Javad
Published: July 2011

An efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS2 in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS2, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses.
Spin Trapping of Radical Intermediates Generated by the Oxidation of Substituted 4‐Methylphenols
Authors: Majzlík Petr , Omelka Ladislav , Superatová Renata , Holubcová Petra
Published: July 2011

A series of substituted 4‐methylphenols 1 and 2 was oxidized with PbO2 in the presence of nitroso compounds 3–10. The formation of adducts of benzyl radicals with the nitroso spin traps in the reaction mixture was established, suggesting the abstraction of an H‐atom from the methyl substituent of 1 or 2. In the consecutive steps, the adducts underwent a further rearrangement to the corresponding nitrones. When the starting phenol contained bulky tBu groups in ortho‐position (see 2,6‐di(tert‐butyl)‐4‐methylphenol (1a)), the stable 2,6‐di(tert‐butyl)‐4R‐phenoxy radicals (R=CHN+(O−)X) were detected as the final radical products. The indirect evidence of nitrones in the reaction mixture was performed in one case by the reaction with a RO$\rm{{_{2}^{{^\cdot} }}}$ radicals.
Studies on the Radical Cyclization of 3‐Oxopropanenitriles and Alkenes with Cerium(IV) Ammonium Nitrate in Ether Solvents
Authors: Yılmaz Mehmet
Published: July 2011

The radical cyclization of 3‐oxopropanenitriles 1a–1e and alkenes 2a–2g with cerium(IV) ammonium nitrate (CAN) in ether solvents was investigated (Tables 1 and 2). In the optimization study, 1,3‐dioxolane, 1,4‐dioxane, 1,2‐dimethoxyethane, Et2O, and THF were used as ether‐based solvents, and the latter was found to be the most effective solvent in radical cyclizations mediated by cerium(IV). This system (cerium(IV)/THF) was applied to cyclizations of various 3‐oxopropanenitriles and 1,3‐dicarbonyl compounds with alkenes resulting in the formation of 4,5‐dihydrofurans in high yields (Table 2 and Scheme 2). The results of the cerium(IV)/THF radical cyclization were compared with those obtained with manganese(III) acetate/AcOH; the cerium(IV)/THF system turned out to be much more efficient.
A Novel Synthesis of γ,δ‐Unsaturated Aldehydes from α‐Formyl‐γ‐lactones
Authors: Snowden Roger L. , Brauchli Robert , Linder Simon
Published: July 2011

A preparatively useful one‐step transformation of γ,γ‐disubstituted α‐formyl‐γ‐lactones into trisubstituted γ,δ‐unsaturated aldehydes is described, by means of catalytic amounts of either AcOH or AcOEt in the vapor phase over a glass support. A mechanistic rationale is proposed.
Simple, Efficient, and Catalyst‐Free Synthesis of (2‐Amino‐4H‐1‐benzopyran‐4‐yl)phosphonates in Polyethylene Glycol
Authors: Das Biswanath , Balasubramanyam Penagaluri , Chinna Reddy Gandolla , Salvanna Nayaki
Published: July 2011

Several (2‐amino‐4H‐1‐benzopyran‐4‐yl)phosphonates were efficiently synthesized by employing a multicomponent protocol involving a salicylaldehyde, malononitrile or ethyl cyanoacetate, and a trialkyl phosphite in polyethylene glycol. The latter could be recovered and re‐used. No additional solvent or catalyst was required. To the best of our knowledge, this is the first report of the one‐pot preparation of (2‐amino‐4H‐1‐benzopyran‐4‐yl)phosphonic acid dimethyl esters.
Synthesis of 9,9‐Disubstituted 9H‐Pyrrolo[1,2‐a]indoles by Hydriodic Acid‐Catalyzed Cyclization of 1‐[2‐(1‐Aryl(or methyl)ethenyl)phenyl]‐1H‐pyrroles
Authors: Kobayashi Kazuhiro , Hashimoto Kenichi , Hashimoto Hiroo , Kondo Hideaki , Konishi Hisatoshi
Published: July 2011

A novel method is reported for the synthesis of 9,9‐disubstituted 9H‐pyrrolo[1,2‐a]indoles. Cyclization of 1‐[2‐(1‐aryl(or methyl)ethenyl)phenyl]‐1H‐pyrroles, which can be easily prepared from 2‐(1‐aryl(or methyl)ethenyl)anilines, proceeds smoothly, in general, at 0° in the presence of a catalytic (or an equimolar) amount of HI in MeCN to provide the desired products.
Oligonucleotide Analogues with Integrated Bases and Backbone. Part 28
Authors: De Giacomo Fabio , Peifer Manuel , Rajic Zrinka , Vasella Andrea
Published: July 2011

The protected hydrazide‐linked uracil‐ and adenine‐derived tetranucleoside analogues 17, 19, and 21 were synthesized in solution by coupling the dimeric hydrazines 6 and 10 with the carboxylic acids 7, 11, and 16. These hydrazines and acids were obtained by partially deprotecting the hydrazines 5, 9, and 15, and these were prepared by coupling the hydrazines 3 and 14 with the carboxylic acids 4 and 8. The crystal structure analysis of the fully protected UU dimer 5 showed the formation of an antiparallel cyclic duplex with the uracil units H‐bonded via HN(3) and OC(2). Stacking interactions were observed between the uracil units with a buckle twist of 30.9°, and between the uracil unit II and the fluoren‐9‐yl group of Fmoc (=9H‐fluoren‐9‐yl)methoxycarbonyl). The hydrazide HN(3′) and the CO group of Fmoc form an intramolecular H‐bond. The uracil‐ and adenine‐derived, water‐soluble hydrazide‐linked self‐complementary octamers 23–32 and the non‐self‐complementary uracil derived decamer 33 were obtained by coupling the carboxylic acids 4 and 8 on a solid support. 1H‐NMR Analysis in CDCl3, mixtures of CDCl3 and (D6)DMSO, and (D8)THF showed that the partially deprotected dimers 5, 6, 12, and 13 form weakly associated linear duplexes. The partially deprotected tetramers 17 and 18 do not associate. The hydrazide‐linked octamers 23–32 do not stack in aqueous solution, and the non‐self‐complementary decamer 33 does not stack with the complementary strands of DNA 43 and RNA 42. The Cbz‐protected amide‐linked octamers 51–56 derived from uracil, adenine, cytosine, and guanine were obtained as the main products by solid‐phase synthesis from the carboxylic acids 46–49. The fully deprotected amide‐linked octamers proved insoluble, and could neither be purified nor analysed.
WAVE2, N‐WASP, and mena facilitate cell invasion via phosphatidylinositol 3‐kinase‐dependent local accumulation of actin filaments
Authors: Takahashi Kazuhide , Suzuki Katsuo
Published: July 2011

Cell migration is accomplished by the formation of cellular protrusions such as lamellipodia and filopodia. These protrusions result from actin filament (F‐actin) rearrangement at the cell cortex by WASP/WAVE family proteins and Drosophila enabled (Ena)/vasodilator‐stimulated factor proteins. However, the role of each of these actin cytoskeletal regulatory proteins in the regulation of three‐dimensional cell invasion remains to be clarified. We found that platelet‐derived growth factor (PDGF) induces invasion of MDA‐MB‐231 human breast cancer cells through invasion chamber membrane pores. This invasion was accompanied by intensive F‐actin accumulation at the sites of cell infiltration. After PDGF stimulation, WAVE2, N‐WASP, and a mammalian Ena (Mena) colocalized with F‐actin at the sites of cell infiltration in a phosphatidylinositol 3‐kinase (PI3K)‐dependent manner. Depletion of WAVE2, N‐WASP, or Mena by RNA interference (RNAi) abrogated both cell invasion and intensive F‐actin accumulation at the invasion site. These results indicate that by mediating intensive F‐actin accumulation at the sites of cell infiltration, WAVE2, N‐WASP, and Mena are crucial for PI3K‐dependent cell invasion induced by PDGF. J. Cell. Biochem. 112: 3421–3429, 2011. © 2011 Wiley Periodicals, Inc.
Predicting the UV spectrum of polyoxometalates by TD‐DFT
Authors: Ravelli Davide , Dondi Daniele , Fagnoni Maurizio , Albini Angelo , Bagno Alessandro
Published: July 2011

UV absorption spectra of the Lindqvist polyoxometalate [W6O19]2− were predicted by relativistic time‐dependent density functional theory with several combinations of density functional and basis set. Hybrid functionals with frozen‐core Slater basis sets were found to provide the best agreement with experiment while keeping reasonable computational demand. The approach was extended to [W10O32]4− and [PW12O40]3−, suggesting that it can be applied to the polyoxometalates family. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Nandrolone and stanozolol induce leydig cell tumor proliferation through an estrogen‐dependent mechanism involving IGF‐I system
Authors: Chimento Adele , Sirianni Rosa , Zolea Fabiana , De Luca Arianna , Lanzino Marilena , Catalano Stefania , Andò Sebastiano , Pezzi Vincenzo
Published: July 2011

Several substances such as anabolic androgenic steroids (AAS), peptide hormones like insulin‐like growth factor‐I (IGF‐I), aromatase inhibitors and estrogen antagonists are offered via the Internet, and are assumed without considering the potential deleterious effects that can be caused by their administration. In this study we aimed to determine if nandrolone and stanozolol, two commonly used AAS, could have an effect on Leydig cell tumor proliferation and if their effects could be potentiated by the concomitant use of IGF‐I. Using a rat Leydig tumor cell line, R2C cells, as experimental model we found that nandrolone and stanozolol caused a dose‐dependent induction of aromatase expression and estradiol (E2) production. When used in combination with IGF‐I they were more effective than single molecules in inducing aromatase expression. AAS exhibited estrogenic activity and induced rapid estrogen receptor (ER)‐dependent pathways involving IGF1R, AKT, and ERK1/2 phosphorylation. Inhibitors for these kinases decreased AAS‐dependent aromatase expression. Up‐regulated aromatase levels and related E2 production increased cell proliferation as a consequence of increased cyclin E expression. The observation that ER antagonist ICI182,780 was also able to significantly reduce ASS‐ and AAS + IGF‐induced cell proliferation, confirmed a role for estrogens in AAS‐dependent proliferative effects. Taken together these data clearly indicate that the use of high doses of AAS, as it occurs in doping practice, enhances Leydig cell proliferation, increasing the risk of tumor development. This risk is higher when AAS are used in association with IGF‐I. To our knowledge this is the first report directly associating AAS and testicular cancer. J. Cell. Physiol. 227: 2079–2088, 2012. © 2011 Wiley Periodicals, Inc.
Motion‐sensitized driven equilibrium for blood‐suppressed T2* mapping
Authors: Newbould Rexford D. , Owen David R.J. , Shalhoub Joseph , Brown Andrew P. , Gambarota Giulio
Published: July 2011

Purpose:

To combine a motion‐sensitized driven equilibrium (MSDE) preparation with a multi‐echo spoiled gradient‐echo sequence (SPGR) to suppress the blood signal intensity in T2* mapping of carotid plaques and liver.

Materials and Methods:

The analytical solution of the Bloch equations for the multi‐echo SPGR sequence, with and without the MSDE preparation, was calculated to optimize sequence parameters. The sequence was implemented at 3 Tesla and T2* maps of carotid plaques and liver were first optimized for blood suppression, and then acquired from five healthy livers and six subjects with ultrasound‐identified carotid plaques.

Results:

Simulations and experimental data showed that the flip angle that gives maximal signal (Ernst angle) in the MSDE‐SPGR was greatly increased from that of pure SPGR. Robust blood suppression was obtained in the T2* maps of carotid plaques and liver, requiring suppression at a field of speed (FOS) of 30 cm/s in both the carotids and liver.

Conclusion:

MSDE provides a means to suppress the blood signal intensity in SPGR sequences. Tissue T2* maps can be obtained without the confounding effects originating from blood vessels. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Three‐dimensional plus time biventricular strain from tagged MR images by phase‐unwrapped harmonic phase
Authors: Venkatesh Bharath Ambale , Schiros Chun G. , Gupta Himanshu , Lloyd Steven G. , Dell'Italia Louis , Denney Thomas S.
Published: July 2011

Purpose:

To validate a method called bi‐ventricular strain unwrapped phase (BiSUP) for reconstructing three‐dimensional plus time (3D+t) biventricular strain maps from phase‐unwrapped harmonic phase (HARP) images derived from tagged cardiac magnetic resonance imaging (MRI).

Materials and Methods:

A set of 30 human subjects were imaged with tagged MRI. In each study, HARP phase was computed and unwrapped in each short‐axis and long‐axis image. Inconsistencies in unwrapped phase were resolved using branch cuts manually placed with a graphical user interface. The 3D strain maps were computed independently in each imaged time frame through systole and mid diastole in each study. The BiSUP strain and displacements were compared with those estimated by a 3D feature‐based (FB) technique and a 2D+t HARP technique.

Results:

The standard deviation of the difference between strains measured by the FB and the BiSUP methods was less than 4% of the average of the strains from the two methods. The correlation between peak minimum principal strain measured using the BiSUP and HARP techniques was over 83%.

Conclusion:

The BiSUP technique can reconstruct full 3D+t strain maps from tagged MR images through the cardiac cycle in a reasonable amount of time and user interaction compared with other 3D analysis methods. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Magnetic resonance elastography of the kidneys: Feasibility and reproducibility in young healthy adults
Authors: Rouvière Olivier , Souchon Rémi , Pagnoux Gaële , Ménager Jean‐Michel , Chapelon Jean‐Yves
Published: July 2011

Purpose:

To evaluate the feasibility and reproducibility of renal magnetic resonance elastography (MRE) in young healthy volunteers.

Materials and Methods:

Ten volunteers underwent renal MRE twice at a 4–5 week interval. The vibrations (45 and 76 Hz) were generated by a speaker positioned beneath the volunteers' back and centered on their left kidney. For each frequency, three sagittal slices were acquired (eight phase offsets per cycle, motion‐encoding gradients successively positioned along the three directions of space). Shear velocity images were reconstructed using the curl operator combined with the local frequency estimation (LFE) algorithm.

Results:

The mean shear velocities measured in the renal parenchyma during the two examinations were not significantly different and exhibited a mean variation of 6% at 45 Hz and 76 Hz. The mean shear velocities in renal parenchyma were 2.21 ± 0.14 m/s at 45 Hz (shear modulus of 4.9 ± 0.5 kPa) and 3.07 ± 0.17 m/s at 76 Hz (9.4 ± 0.8 kPa, P < 0.01). The mean shear velocities in the renal cortex and medulla were respectively 2.19 ± 0.13 m/s and 2.32 ± 0.16 m/s at 45 Hz (P = 0.002) and 3.06 ± 0.16 m/s and 3.10 ± 0.22 m/s at 76 Hz (P = 0.13).

Conclusion:

Renal MRE was feasible and reproducible. Two independent measurements of shear velocities in the renal parenchyma of the same subjects showed an average variability of 6%. J. Magn. Reson. Imaging 2011;. ©2011 Wiley‐Liss, Inc.
Novel segmentation method for abdominal fat quantification by MRI
Authors: Zhou Anqi , Murillo Horacio , Peng Qi
Published: July 2011

Purpose:

To introduce and describe the feasibility of a novel method for abdominal fat segmentation on both water‐saturated and non–water‐saturated MR images with improved absolute fat tissue quantification.

Materials and Methods:

A general fat distribution model which fits both water‐saturated (WS) and non–water‐saturated (NWS) MR images based on image gray‐level histogram is first proposed. Next, a novel fuzzy c‐means clustering step followed by a simple thresholding is proposed to achieve automated and accurate abdominal quantification taking into consideration the partial‐volume effects (PVE) in abdominal MR images. Eleven subjects were scanned at central abdomen levels with both WS and NWS MRI techniques. Synthesized “noisy” NWS (nNWS) images were also generated to study the impact of reduced SNR on fat quantification using the novel approach. The visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) amounts of the WS MR images were quantified with a traditional intensity thresholding method as a reference to evaluate the performance of the novel method on WS, NWS, and nNWS MR images.

Results:

The novel approach resulted in consistent SAT and VAT amounts for WS, NWS, and nNWS images. Automatic segmentation and incorporation of spatial information during segmentation improved speed and accuracy. These results were in good agreement with those from the WS images quantified with a traditional intensity thresholding method and accounted for PVE contributions.

Conclusion:

The proposed method using a novel fuzzy c‐means clustering method followed by thresholding can achieve consistent quantitative results on both WS and NWS abdominal MR images while accounting for PVE contributing inaccuracies. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Assessment of fast dynamic imaging and the use of Gd‐EOB‐DTPA for MR‐guided liver interventions
Authors: Fischbach Frank , Thormann Markus , Seidensticker Max , Kropf Siegfried , Pech Maciej , Ricke Jens
Published: July 2011

Purpose:

1) To analyze and compare fast dynamic imaging sequences to biopsy suspect liver lesions. 2) To evaluate the additional use of hepatocyte‐specific contrast agent compared to the nonenhanced fast dynamic scans and diagnostic liver imaging.

Materials and Methods:

Image acquisition was performed using a 1T open‐configured scanner suitable for interventional purposes. Transversal postcontrast T1‐weighted (T1w) fat‐saturated 3D high‐resolution examination (THRIVE) images were acquired >20 minutes postintravenous application of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd‐EOB‐DTPA). A single slice, crossing the level of the lesion, was acquired using intermediate‐weighted steady‐state free‐precession (bTFE), T1w‐gradient echo and spin echo (T1FFE/TSE), T2w‐spin echo (sshTSE) sequences. T1w imaging was acquired prior and after contrast media application. Diagnostic and fast dynamic images were compared based on a 10‐point rating scale. In addition, the liver‐to‐lesion‐contrast ratio was measured.

Results:

A total of 39 malignant lesions with a mean diameter of 13 mm (5–30 mm) in 39 patients were included. Concerning a test of noninferiority, there was no significant difference between rating score values of fast dynamic imaging employing contrast‐enhanced T1FFE‐sequences compared to diagnostic THRIVE (P = 0.001). Calculated liver‐to‐lesion contrast also showed no difference for either imaging sequence (P = 1.0). All other sequences tested showed significant inferiority (P ≤ 0.001).

Conclusion:

T1w Gd‐EOB‐DTPA contrast‐enhanced fast dynamic GRE imaging significantly improves the contrast behavior of malignant liver lesions comparable to diagnostic imaging and is best suited for liver intervention, especially at 1T open magnetic resonance imaging. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Rapid identification of phase I and II metabolites of artemisinin antimalarials using LTQ‐Orbitrap hybrid mass spectrometer in combination with online hydrogen/deuterium exchange technique
Authors: Liu Tian , Du Fuying , Wan Yakun , Zhu Fanping , Xing Jie
Published: July 2011

Artemisinin drugs have become the first‐line antimalarials in areas of multi‐drug resistance. However, monotherapy with artemisinin drugs results in comparatively high recrudescence rates. Autoinduction of CYP‐mediated metabolism, resulting in reduced exposure, has been supposed to be the underlying mechanism. To better understand the autoinduction of artemisinin drugs, we evaluated the biotransformation of artemisinin, also known as Qing‐hao‐su (QHS), and its active derivative dihydroartemisinin (DHA) in vitro and in vivo, using LTQ‐Orbitrap hybrid mass spectrometer in conjunction with online hydrogen (H)/deuterium (D) exchange high‐resolution (HR)‐LC/MS (mass spectrometry) for rapid structural characterization. The LC separation was improved allowing the separation of QHS parent drugs and their metabolites from their diastereomers. Thirteen phase I metabolites of QHS have been identified in liver microsomal incubates, rat urine, bile and plasma, including six deoxyhydroxylated metabolites, five hydroxylated metabolites, one dihydroxylated metabolite and deoxyartemisinin. Twelve phase II metabolites of QHS were detected in rat bile, urine and plasma. DHA underwent similar metabolic pathways, and 13 phase I metabolites and 3 phase II metabolites were detected. Accurate mass data were obtained in both full‐scan and MS/MS mode to support assignments of metabolite structures. Online H/D exchange LC‐HR/MS experiments provided additional evidence in differentiating deoxydihydroxylated metabolites from mono‐hydroxylated metabolites. The results showed that the main phase I metabolites of artemisinin drugs are hydroxylated and deoxyl products, and they will undergo subsequent phase II glucuronidation processes. This study also demonstrated the effectiveness of online H/D exchange LC‐HR/MSn technique in rapid identification of drug metabolites. Copyright © 2011 John Wiley & Sons, Ltd.
Fragmentation features of intermolecular cross‐linked peptides using N‐hydroxy‐ succinimide esters by MALDI‐ and ESI‐MS/MS for use in structural proteomics
Authors: Santos Luiz F. A. , Iglesias Amadeu H. , Gozzo Fabio C.
Published: July 2011

The use of mass spectrometry coupled with chemical cross‐linking of proteins has become one of the most useful tools for proteins structure and interactions studies. One of the challenges in these studies is the identification of the cross‐linked peptides. The interpretation of the MS/MS data generated in cross‐linking experiments using N‐hydroxy succinimide esters is not trivial once a new amide bond is formed allowing new fragmentation pathways, unlike linear peptides. Intermolecular cross‐linked peptides occur when two different peptides are connected by the cross‐linker and they yield information on the spatial proximity of different domains (within a protein) or proteins (within a complex). In this article, we report a detailed fragmentation study of intermolecular cross‐linked peptides, generated from a set of synthetic peptides, using both ESI and MALDI to generate the precursor ions. The fragmentation features observed here can be helpful in the interpretation and identification of cross‐linked peptides present in cross‐linking experiments and be further implemented in search engine's algorithms. Copyright © 2011 John Wiley & Sons, Ltd.