bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the principal nucleus trigeminal lemniscal projections in the mouse
Authors: Kivrak Beril G. , Erzurumlu Reha S.
Published: July 2012

The principal sensory (PrV) nucleus‐based trigeminal lemniscus conveys whisker‐specific neural patterns to the ventroposteromedial (VPM) nucleus of the thalamus and subsequently to the primary somatosensory cortex. Here we examined the perinatal development of this pathway with carbocyanine dye labeling in embryonic and early postnatal mouse brains. We developed a novel preparation in which the embryonic hindbrain and the diencephalon are flattened out, allowing a birds‐eye view of the PrV lemniscus in its entirety. For postnatal brains we used another novel approach by sectioning the brain along an empirically determined oblique horizontal angle, again preserving the trigeminothalamic pathway. PrV neurons are born along the hindbrain ventricular zone and migrate radially for a short distance to coalesce into a nucleus adjacent to the ascending trigeminal tract. During migration of the spindle‐shaped cell bodies, slender axonal processes grow along the opposite direction towards the floor plate. As early as embryonic day (E) 11, pioneering axons tipped with large growth cones cross the ventral midline and immediately make a right angle turn. By E13 many PrV axons form fascicles crossing the midline and follow a rostral course. PrV axons reach the midbrain by E15 and the thalamus by E17. While the target recognition and invasion occurs prenatally, organization of PrV axon terminals into whisker‐specific rows and patches takes place during the first 4 postnatal (P) days. Initially diffuse and exuberant projections in the VPM at P1 coalesce into row and whisker specific terminal zones by P4. J. Comp. Neurol. 521:299–311, 2013. © 2012 Wiley Periodicals, Inc.
Sex‐specific expression of estrogen receptors α and β and Kiss1 in the postnatal rat amygdala
Authors: Cao Jinyan , Patisaul Heather B.
Published: July 2012

The rodent amygdaloid complex is composed of numerous subnuclei important for the sex‐specific regulation of sociosexual behavior. Although estrogen receptors (ERs) are critical for organizing functional and cytoarchitectural sex differences in these subnuclei, a detailed developmental profile of ER expression in the amygdaloid complex is not available. Moreover, the kisspeptin gene (Kiss1) was recently identified in the adult amygdala, but it remains unknown if it is expressed during development. To fill these data gaps, rat brains (5–7/group) were assessed on postnatal days (PNDs) 0, 2, 4, 7, and 19 for ER alpha (ERα; Esr1), beta (ERβ; Esr2), and Kiss1 expression using in situ hybridization. Expression was quantified in the posterodorsal portion of the medial amygdala posterodorsal (MePD), lateral (PLCo), and medial (PMCo) components of the posterior cortical nucleus, and the amygdalohippocampal area (AHi). ERα expression was high throughout the amygdala at birth, but sexually dimorphic only in the AHi. ERα expression in the MePD and the PLCo showed a U‐shaped expression pattern over time. In the PMCo, ERα expression decreased from PND 2 and remained low through PND 19. Sexually dimorphic expression of ERβ in the MePD was observed on PND 0, with higher levels in females, but reversed by PND 4 due to declining levels in females. No Kiss1 signal was observed in the postnatal amygdala, suggesting that expression arises after puberty. These data reveal that ER expression is region‐specific within the neonatal amygdala. These differences likely contribute to sex differences in sociosexual behavior across the lifespan. J. Comp. Neurol. 521:465–478, 2013. © 2012 Wiley Periodicals, Inc.
Glutamatergic neuronal populations in the brainstem of the sea lamprey, Petromyzon marinus: An in situ hybridization and immunocytochemical study
Authors: Villar‐Cerviño Verona , Barreiro‐Iglesias Antón , Fernández‐lópez Blanca , Mazan Sylvie , Rodicio María Celina , Anadón Ramón
Published: July 2012

Glutamate is the major excitatory neurotransmitter in vertebrates, and glutamatergic cells probably represent a majority of neurons in the brain. Physiological studies have demonstrated a wide presence of excitatory (glutamatergic) neurons in lampreys. The present in situ hybridization study with probes for the lamprey vesicular glutamate transporter (VGLUT) provides an anatomical basis for the general distribution and precise localization of glutamatergic neurons in the sea lamprey brainstem. Most glutamatergic neurons were found within the periventricular gray layer throughout the brainstem, with the following regions being of particular interest: the optic tectum, torus semicircularis, isthmus, dorsal and medial nuclei of the octavolateral area, dorsal column nucleus, solitary tract nucleus, motoneurons, and reticular formation. The reticular population revealed a high degree of cellular heterogeneity including small, medium‐sized, large, and giant glutamatergic neurons. We also combined glutamate immunohistochemistry with neuronal tract‐tracing methods or γ‐aminobutyric acid (GABA) immunohistochemistry to better characterize the glutamatergic populations. Injection of Neurobiotin into the spinal cord revealed that retrogradely labeled small and medium‐sized cells of some reticulospinal‐projecting groups were often glutamate‐immunoreactive, mostly in the hindbrain. In contrast, the large and giant glutamatergic reticulospinal perikarya mostly lacked glutamate immunoreactivity. These results indicate that glutamate immunoreactivity did not reveal the entire set of glutamatergic populations. Some spinal‐projecting octaval populations lacked both VGLUT and glutamate. As regards GABA and glutamate, their distribution was largely complementary, but colocalization of glutamate and GABA was observed in some small neurons, suggesting that glutamate immunohistochemistry might also detect non‐glutamatergic cells or neurons that co‐release both GABA and glutamate. J. Comp. Neurol. 521:522–557, 2013. © 2012 Wiley Periodicals, Inc.
Self‐Assembled Monolayers of Single‐Molecule Magnets [Tb{Pc′(SR)8}2] on Gold
Authors: Glebe Ulrich , Weidner Tobias , Baio Joe E. , Schach Denise , Bruhn Clemens , Buchholz Axel , Plass Winfried , Walleck Stephan , Glaser Thorsten , Siemeling Ulrich
Published: July 2012

The magnetic properties of the bis(phthalocyaninato)terbium complexes [Tb{Pc′(SR)8}2] (1) containing eight β‐positioned long‐chain alkylthio substituents SR (a: R=n‐C8H17, b: R=n‐C12H25) were studied by SQUID measurements, which revealed that both compounds are single‐molecule magnets with an effective energy barrier for spin reversal significantly higher than that found for pristine bis(phthalocyaninato)terbium [Tb(Pc)2]. Thin films on gold were fabricated from 1 a and 1 b by chemisorption from solution and were characterised by near‐edge X‐ray absorption fine structure (NEXAFS) and X‐ray photoelectron spectroscopy (XPS). In the case of 1 a, atomic force microscopy (AFM) was used in addition. The results are in accord with the formation of self‐assembled monolayers which contain the macrocyclic rings mainly in an approximately horizontal orientation. The chemisorption is primarily due to the peripheral SR substituents, giving rise to coordinatively bound thioether units, whose alkyl chains are in an almost parallel orientation with respect to the surface. In the case of 1 b, covalently attached thiolate units were also observed, indicating that the chemisorption process can lead to carbon–sulfur bond cleavage. In addition, the crystal structure of 1 a was determined.
Ethylene Production by ODHE in Catalytically Modified Ba0.5Sr0.5Co0.8Fe0.2O3−δ Membrane Reactors
Authors: Lobera M. Pilar , Escolástico Sonia , Garcia‐Fayos Julio , Serra José M.
Published: July 2012

Process intensification by the integration of membranes and high‐temperature reactors offers several advantages with regard to conventional process schemes, that is, energy saving, safe operation, reduced plant/unit size, and higher process performance, for example, higher productivity, catalytic activity, selectivity, or stability. We present the study of oxidative dehydrogenation of ethane at 850 °C on a catalytic membrane reactor based on a mixed ionic–electronic conducting membrane. The surface of the membrane made of Ba0.5Sr0.5Co0.8Fe0.2O3−δ has been activated by using different porous catalytic layers based on perovskites. The layer was deposited by screen printing, and the porosity and thickness was studied for the catalyst composition. The different catalyst formulations are based on partial substitution of A‐ and B‐site atoms of doped strontium ferrite/cobaltites (A0.6Sr0.4Co0.5Fe0.5O3−δ and Ba0.6Sr0.4BO3−δ) and were synthesized by an ethylenediaminetetraacetic acid–citrate complexation route. The use of a disk‐shaped membrane in the reactor enabled the direct contact of gaseous oxygen and hydrocarbons to be avoided, and thus, the ethylene content increased. High ethylene yields (up to ≈81 %) were obtained by using a catalytic coating based on Ba0.5Sr0.5Co0.8Fe0.2O3−δ, which included macropores produced by the addition of graphite platelets into the screen‐printing ink. The promising catalytic results obtained with this catalytically modified membrane reactor are attributed to the combination of 1) the high activity, as a result of the high temperature and oxygen species diffusing through the membrane; 2) the control of oxygen dosing and the low concentration of molecules in the gas phase; and 3) suitable fluid dynamics, which enables appropriate feed contact with the membrane and the rapid removal of products.
Diketopyrrolopyrrole–Porphyrin Conjugates as Broadly Absorbing Sensitizers for Dye‐Sensitized Solar Cells
Authors: Warnan Julien , Favereau Ludovic , Meslin Frédéric , Severac Marjorie , Blart Errol , Pellegrin Yann , Jacquemin Denis , Odobel Fabrice
Published: July 2012

A series of four new push–pull zinc porphyrin‐based dyes was synthesised for hybrid photovoltaic solar cells with a view to enhancing the light‐harvesting efficiency at approximately 550 nm with a diketopyrrolopyrrole (DPP) unit. The strength of the donor side of the push–pull porphyrin was tuned by affixing the electron‐rich 4,4′‐dimethoxydiphenylamine group at the meso position of the macrocycle, and the influence of the distance between the semiconductor surface and the porphyrin chromophore was assessed by introducing different π‐conjugated spacers. Charge‐transfer transitions over great distances were characterised by electronic absorption spectroscopy and DFT calculations. The absorption and photoactivity spectra of the new bichromophoric dyes spans the whole visible spectrum to the red, implying a better light‐harvesting efficiency than regular porphyrin as the absorption spectra of DPP and porphyrin complement one another. Photovoltaic conversion efficiencies accordingly increase from 2.40 to 5.19 %. Interestingly, the best overall efficiency was reached with dye 3, which lacks the powerful donating group in the meso position of the porphyrin core. Optical and electrochemical measurements coupled to time dependent (TD)‐DFT calculations give insight into the deleterious effect of the 4,4′‐dimethoxydiphenylamine unit on the photovoltaic performances, paving the way towards the design of efficient push–pull porphyrin‐based sensitizers.
Cytometric and biochemical characterization of human breast cancer cells reveals heterogeneous myoepithelial phenotypes
Authors: Leccia Felicia , Nardone Agostina , Corvigno Sara , Vecchio Luigi Del , De Placido Sabino , Salvatore Francesco , Veneziani Bianca Maria
Published: July 2012

To determine whether cell cultures maintain the cellular heterogeneity of primary tissues and may therefore be used for in vitro modeling of breast cancer subtypes, we evaluated the expression of a cell surface marker panel in breast cancer cell cultures derived from various subtypes of human breast carcinoma. We used a four‐color flow cytometry strategy to immunophenotype seven human breast cancer cell cultures and four reference breast cancer cell lines. We analyzed 28 surface markers selected based on their potential to distinguish epithelial or mesenchymal lineage, to identify stem cell populations, and to mediate cell adhesion and migration. We determined their ability to form mammospheres and analyzed luminal cytokeratins CK18, CK19, and myoepithelial/basal CK5, SMA (alpha‐smooth muscle actin), and vimentin expression by western blot. All cell surface markers showed a unimodal profile. Ten/28 markers were homogenously expressed. Four (CD66b, CD66c, CD165, CD324) displayed negative/low expression. Six (CD29, CD55, CD59, CD81, CD151, CD166) displayed homogenous high expression. Eighteen (CD9, CD10, CD24, CD26, CD44, CD47, CD49b, CD49f, CD54, CD61, CD90, CD105, CD133, CD164, CD184, CD200, CD227, CD326) were heterogeneously expressed. Spearman's rank test demonstrated a significant correlation (p< 0.001) between mesenchymal phenotype and breast cancer cell cultures. Breast cancer cell cultures, all CD44+, displayed concomitant high expression of only three antigens (CD10, CD54, CD90), and low expression of CD326; cell cultures formed mammospheres and expressed CK5, SMA and vimentin, and were weakly CK19‐positive. We demonstrate that breast cancer cell cultures preserve inter‐tumor heterogeneity and express stem/progenitor markers that can be identified, quantified and categorized by flow cytometry. Therefore, cell cultures can be used for in vitro modeling of breast cancer subtypes; immunophenotyping may mirror breast cancer heterogeneity and reveal molecular characteristics of individual tumors useful for testing target therapy. © 2012 International Society for Advancement of Cytometry
Complementary stable carbon isotope ratio and amount of substance measurements in sports anti‐doping
Authors: Cawley Adam T. , George Adrian V.
Published: July 2012

The detection of steroids originating from synthetic precursors against a background of their chemically identical natural analogues has proven to be a significant challenge for doping control laboratories accredited by the World Anti‐Doping Agency (WADA). The complementary application of gas chromatography–mass spectrometry (GC‐MS) and gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS) has been demonstrated to provide specific detection of endogenous steroid misuse for improved anti‐doping analysis. Markers of synthetically derived steroids are reviewed on the basis of abnormal urinary excretions and low13C content. A combinatorial approach is presented for the interpretation of GC‐MS and GC‐C‐IRMS data in the anti‐doping context. This methodology can allow all relevant information concerning an individual's metabolism to be assessed in order to make an informed decision with respect to a doping violation. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of WN(NMe2)3 as a Precursor for the Deposition of WNx Nanospheres
Authors: McClain K. Randall , O'Donohue Christopher , Shi Zhiwei , Walker Amy V. , Abboud Khalil A. , Anderson Tim , McElwee‐White Lisa
Published: July 2012

The WNx precursor WN(NMe2)3 was prepared from WN(OtBu)3 and Zr(NMe2)4 by using an amide/alkoxide exchange reaction. Structural analysis of WN(NMe2)3 revealed an overall pseudo‐tetrahedral geometry with a distortion towards trigonal pyramidal. Aerosol‐assisted chemical vapor deposition (AACVD) from WN(NMe2)3 resulted in deposition of WNx nanospheres onto Si(100) and Si(111) substrates at low temperatures (75–125 °C). The nanospheres were imaged by SEM and characterized by using energy dispersive spectroscopy (EDS) and X‐ray photoelectron spectroscopy (XPS). These preliminary results demonstrate the viability of WN(NMe2)3 as a single‐source precursor for the deposition of WNx at low temperature.
Synthesis and Characterization of Pyrylogens Possessing Low Excitation Energies – Substituent Modification in Order to Improve Solar Energy Collection
Authors: El‐Idreesy Tamer T.
Published: July 2012

The synthesis and characterization of the first di‐β‐naphthyl‐substituted pyrylogens, N‐methyl‐2,6‐di‐β‐naphthyl‐4,4′‐pyrylogen bis(tetrafluoroborate) and N‐methyl‐2,6‐di‐β‐naphthyl‐4,2′‐pyrylogen bis(tetrafluoroborate) are reported. The photophysical and electrochemical behaviors of these new pyrylogens are examined and compared to the previously reported diphenyl‐substituted analogs, N‐methyl‐2,6‐diphenyl‐4,4′‐pyrylogen bis(tetrafluoroborate) and N‐methyl‐2,6‐diphenyl‐4,2′‐pyrylogen bis(tetrafluoroborate) as well as to 2,4,6‐triphenylpyrylium tetrafluoroborate, the typical electron‐transfer photocatalyst. The newly synthesized pyrylogens exhibit substantially lower excitation energies. The results are supported by theoretical calculations using the B3LYP/6‐31G(d) and time‐dependent DFT (TD‐DFT) CAM‐B3LYP/6‐31G(d) computational models. In addition, insight into the reduction reactions of the new pyrylogens to their radical cation and neutral redox partners is also provided.
AgI‐Catalyzed Cascade Strategy: Regioselective Access to Diversely Substituted Fused Benzimidazo[2,1‐a]isoquinolines, Naphthyridines, Thienopyridines, and Quinoxalines in Water
Authors: Rustagi Vineeta , Tiwari Rakesh , Verma Akhilesh Kumar
Published: July 2012

An environmentally benign and operationally simple one‐pot approach to the regioselective tandem synthesis of diversely substituted fused benzimidazo[2,1‐a]isoquinolines, naphthyridines, thienopyridines, and quinoxalines from o‐alkynylaldehydes and arylamines with tethered nucleophiles using AgI as catalyst in water is described. The reaction showed selective N–C bond formation on the more electrophilic alkynyl carbon, resulting in the regioselective 6‐endo‐dig cyclized products in good to excellent yields. The proposed mechanistic pathway for the synthesis of fused heterocycles proceeding through formation of ring A prior to ring B, which formed through a second intramolecular attack of the nitrogen onto the alkynyl carbon, was supported by mechanistic experiments and X‐ray crystallographic studies of isolated intermediate U and cyclized product 5a. Comparative experiments showed the viability of intramolecular nucleophilic attack over intermolecular attack of an external nucleophile. This catalytic, green protocol has been efficiently applied for the bis‐tandem cyclization in water.
Conformational Dynamics of a Central Trisaccharide Fragment of the LeaLex Tumor Associated Antigen Studied by NMR Spectroscopy and Molecular Dynamics Simulations
Authors: Zaccheus Mona , Pendrill Robert , Jackson Trudy A. , Wang An , Auzanneau France‐Isabelle , Widmalm Göran
Published: July 2012

Certain carbohydrate structures are recognized as cancer antigens, and identification of these and relevant epitopes are essential in fighting the disease. The trisaccharide β‐D‐GlcpNAc‐(1→3)‐β‐D‐Galp‐(1→4)‐β‐D‐GlcpNAc‐OMe represents a model for the central region of the LeaLex hexasaccharide and it has herein been investigated by 1D 1H,1H‐NOESY experiments to obtain effective interresidue proton–proton distances as well as by 2D J‐HMBC experiments to determine transglycosidic 3JCH coupling constants. Molecular dynamics (MD) simulations using explicit water as solvent and three different carbohydrate force fields, namely, GLYCAM06, PARM22/SU01, and CHARMM2011, were employed for the interpretation of experimental data. Overall, the force field based MD simulations are able to reproduce the experimental data and the ψ torsion angle at the β‐(1→3)‐linkage is concluded to be flexible. In addition, different minor states were present for the three force fields with either anti‐ψ or non‐exo‐anomeric conformations. Transitions between the exo‐anomeric and the non‐exo‐anomeric conformations for the φ torsion angle at the β‐(1→4)‐linkage in one of the MD simulations were analyzed in detail. It was found that hydrogen‐bonding water molecules, interresidue hydrogen bonds and the transitions between antiperiplanar and synperiplanar conformations for the τH torsion angle of an N‐acetyl group were all essential in the description of the glycosidic transition process. In particular, the transition of τH may be a general way of regulating other transitions into less populated but biologically important conformational regions.
Interruption of nuclear localization of ATBF1 during the histopathologic progression of head and neck squamous cell carcinoma
Authors: Sun Xiaodong , Li Jie , Sica Gabriel , Fan Song‐Qing , Wang Yuxiang , Chen Zhengjia , Muller Susan , Chen Zhuo (Georgia) , Fu Xiaoying , Dong Xue‐Yuan , Guo Peng , Shin Dong M. , Dong Jin‐Tang
Published: July 2012

Background

The AT‐motif binding factor 1 (ATBF1) gene is frequently altered at the genetic level in several types of cancer, but its protein expression and subcellular localization have not been well studied in human cancers, including head and neck squamous cell carcinomas (HNSCCs).

Methods

ATBF1 expression and localization were examined in 5 cell lines and 197 clinical specimens of HNSCC, and correlated with pathologic and clinical characteristics.

Results

ATBF1 was predominantly localized in the nucleus of hyperplastic squamous epithelium. Whereas nuclear ATBF1 dramatically decreased in invasive tumors (p = .0012), cytoplasmic ATBF1 levels progressively increased from dysplasia to invasive tumors (p < .0001), and the increase correlated with poor survival. Reduced nuclear ATBF1 level was also detected in HNSCC cell lines.

Conclusions

Nuclear localization of ATBF1 is frequently interrupted in HNSCC, and the interruption is significantly associated with the progression of HNSCC. The cytoplasmic ATBF1 level could be useful for predicting patient survival. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Minimally invasive video‐assisted thyroidectomy: Learning curve in terms of mean operative time and conversion and complication rates
Authors: Pons Yoann , Vérillaud Benjamin , Blancal Jean–Philippe , Sauvaget Elisabeth , Cloutier Tam , Le Clerc Nicolas , Herman Philippe , Kania Romain
Published: July 2012

Background

The purpose of this study was to evaluate the learning curve for minimally invasive video‐assisted thyroidectomy (MIVAT).

Methods

Fifty consecutive patients were prospectively included in groups corresponding to their surgical order (10 patients in each group).

Results

The mean operation times between 2 neighboring groups were 33.9 minutes longer in group 1 than in group 2 (p = .01) and 25.8 minutes longer in group 3 than in group 4 (p = .002). The conversion rate for technical difficulties in group 1 was 6% (3 of 50). The definitive complication rate was 2% (1 of 50).

Conclusions

In terms of operative time, 10 patients represented the early stage of the learning curve, and 30 patients represented the number of procedures required to reach an advanced level of skill. Considering the low conversion and complication rates, improved aesthetic results and postoperative course, MIVAT should become a tool in the repertoire of high‐volume thyroid surgeons. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Transformation/dissolution examination of antimony and antimony compounds with speciation of the transformation/dissolution solutions
Authors: Skeaff James M , Beaudoin Robert , Wang Ruiping , Joyce Barry
Published: July 2012

Speciation is held to be a key factor in controlling the ecotoxicity of metals in solution. Using the United Nations transformation/dissolution protocol (T/DP) for metals and sparingly soluble metal compounds, we have examined the transformation/dissolution (T/D) characteristics in terms of the concentrations of total dissolved Sb at pH 6 and 8.5 in 1, 10, and 100 mg/L loadings over 7 d as well as the concentrations of Sb(III) and Sb(V) at the 1 mg/L loadings over 28 d, of sodium hexahydroxoantimonate (NaSb(OH)6), antimony metal (Sb), antimony trioxide (Sb2O3), antimony sulfide (Sb2S3), sodium antimonate (NaSbO3), antimony tris(ethylene glycolate) (Sb2(C2H4O2)3), antimony trichloride (SbCl3), antimony triacetate (Sb(CH3COO)3), and antimony pentoxide (Sb2O5). We also measured the concentrations of the dissolved Sb(III) and Sb(V) species at the 1 mg/L loadings. Because of complexing, the trivalent organic Sb compounds exhibited little or no oxidation of Sb(III) to Sb(V). However, oxidation of Sb(III) to Sb(V) was evident for the trivalent inorganic Sb compounds. Conversely, with pentavalent Sb compounds, there was no reduction of Sb(V) to Sb(III). Based on the percentage of Sb in the compound dissolved or metal reacted at 28 d and 1 mg/L loadings, the solubility rankings at pH 6 are NaSb(OH)6 > Sb(CH3COO)3 > Sb metal > Sb2(C2H4O2)3 > Sb2S3 > Sb2O3 > NaSbO3 ≈ SbCl3 > Sb2O5. For pH 8.5 the order is NaSb(OH)6 > Sb(CH3COO)3 > Sb metal > Sb2(C2H4O2)3 > SbCl3 > Sb2O3 > Sb2S3 > NaSbO3 > Sb2O5. We provide worked examples of how the T/D data have been used to derive hazard classification proposals for Sb metal and these selected compounds for submission to the European Chemicals Agency under the Registration, Evaluation, Authorization and Restriction of CHemicals (REACH) legislation. Integr Environ Assess Manag 2013; 9: 98–113. © 2012 SETAC
Light‐Activated Pharmaceuticals: Mechanisms and Detection
Authors: Kessel David , Reiners John
Published: July 2012

Photodynamic therapy relies on the interaction between light, oxygen and a photosensitizing agent. Its medical significance relates to the ability of certain agents, usually based on porphyrin or phthalocyanine structures, to localize somewhat selectively in neoplastic cells and their vasculature. Subsequent irradiation, preferably at a sufficiently high wavelength to have a significant pathway through tissues, results in a photophysical reaction whereby the excited state of the photosensitizing agent transfers energy to molecular oxygen and results in the formation of reactive oxygen species. Analogous reactive nitrogen species are also formed. These contain both nitrogen and oxygen atoms. The net result is both direct tumor cell death and a shutdown of the tumor vasculature. Other processes may also occur that promote the anti‐tumor response but these are outside the scope of this review.
The Role of Symmetry in Asymmetric Catalysis
Authors: Moberg Christina
Published: July 2012

Chiral ligands and metal complexes with rotational (Cn, Dn) symmetry often have beneficial properties in asymmetric catalysis. The enhanced enantioselectivity frequently observed is a result of a reduction of competing reaction routes. This may be due to rotational symmetry in the catalyst, leading to a limited number of different catalyst‐substrate interactions, or to formation of a limited number of catalytic species as a result of rotational symmetry in the ligand. The effect of symmetry is usually difficult to evaluate, since a change in symmetry properties necessarily is accompanied by structural modifications. In each situation the number of intermediate complexes, their electronic and steric properties, and their energy need to be analyzed. Although other factors may be more important than symmetry for achieving high enantioselectivity, a vast number of C2‐ and to some extent C3‐symmetric ligands have been found to have excellent properties in asymmetric catalysis, providing products with high enantiomeric purity. Besides the benefit of symmetry in the ligand and catalyst, the symmetry of the substrate may be important since a gain in enantioselectivity can result from simultaneous asymmetric transformations of homotopic functional groups.
Ecotoxicity and screening level ecotoxicological risk assessment of five antimicrobial agents: triclosan, triclocarban, resorcinol, phenoxyethanol and p‐thymol
Authors: Tamura Ikumi , Kagota Kei‐ichiro , Yasuda Yusuke , Yoneda Saori , Morita Junpei , Nakada Norihide , Kameda Yutaka , Kimura Kumiko , Tatarazako Norihisa , Yamamoto Hiroshi
Published: July 2012

Acute and chronic (or sub‐chronic) toxicity of five selected antimicrobial agents, including triclosan (TCS), triclocarban (TCC), resorcinol, phenoxyethanol and p‐thymol, was investigated using the conventional three‐aquatic‐organism battery. These compounds are widely used in cosmetics and other personal care products and their ecological risk has recently become a significant concern. As results of toxicity tests, TCS was found to be most strongly toxic for green algae [e.g. 72 h no observed effect concentration (NOEC) of 0.50 µg l−1] among the selected compounds, followed by TCC, while TCC was more toxic or similar to TCS for Daphnia and fish (e.g. Daphnia 8 day NOEC of 1.9 µg l−1). Having compared the predicted no effect concentration (PNEC) determined from the toxicity data with measured environmental concentrations (MEC), the preliminary ecological risk assessment of these five antimicrobials was conducted. The MEC/PNEC ratios of TCS and TCC were over 1 for some monitoring data, especially in urban streams with watershed areas without sewage service coverage, and their potential risk for green algae and Daphnia might be at a level of concern, although the contribution of TCS/TCC on the total toxicity of the those sites needs to be further investigated. For the three other antimicrobials, the maximum MEC/PNEC ratio for resorcinol was 0.1–1, but those for phenoxyethanol and p‐thymol were <0.1 and their risk to aquatic organisms is limited, although the additive effects with TCS, TCC and other antimicrobial agents, such as parabens, need to be further examined in future studies. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Structure and Conformation on Fluorescence Properties in Novel Coumarin‐based Mannich Base Dyes
Authors: Ni Xiaobo , Guo Yuan , Bu Huaiyu , An Jing , En Da
Published: July 2012

Twelve novel coumarin‐based Mannich base dyes have been synthesized via introducing functional aminomethyl group at the 8 position of coumarin ring by Mannich reaction and their chemical structures were confirmed by IR, 1H NMR, MS and elemental analysis. Moreover, the fluorescence intensities and relative quantum yields of all the dyes were measured and studied. The results illustrated that the heavy atom effect was obvious in our designed system and there was a relationship between the structures, the conformations and the fluorescence spectra of the coumarins. Meanwhile, the present β‐CD titration experiment illustrated that the aniline nitrogen atom was closely related to the photoinduced electron transfer (PET) course and the PET course was carried out via a conformational control mechanism.
Zwitterionic Salts from the Reaction of Symmetrical and Unsymmetrical (thio)Barbituric Acids with 2‐Pyridinecarbaldehyde under Solvent‐free Condition
Authors: Pesyan Nader Noroozi , Hosseini Yaser , Shokr Alireza , Şahin Ertan
Published: July 2012

A simple and efficient synthesis for the preparation of unusual charge‐separated pyridinium (thio)barbiturate zwitterion derivatives was achieved via a one‐pot reaction of (thio)barbituric acid derivatives and 2‐pyridinecarbaldehyde under solvent‐free condition and also in methanol under refluxing. The structure of the compounds was confirmed by 1H NMR, 13C NMR, FT‐IR, mass and X‐ray analysis. The mechanism of the formation is discussed. Instead, no related pyridinium zwitterion was afforded from the reaction between dimedone and 2‐pyridinecarbaldehyde under the same conditions and its xanthene derivative was obtained.
Mechanochemical Synthesis of Tin Nanowires for Anodes in Li+ Ion Secondary Batteries
Authors: Tapia‐Ruiz Nuria , Nithya C. , Jayakrishnan Sobha , Gopukumar S. , Gregory Duncan H.
Published: July 2012

Tin micro‐ and nanowires have been synthesised for the first time via high‐energy ball milling techniques. Typically nanowires with diameters measuring ca. 500 nm and lengths of up to 100 μm were fabricated by milling powders of tin metal and lithium nitride, Li3N in 3:1 or 5:1 molar ratios. The as‐prepared products were characterised and analysed by powder X‐ray diffraction (PXRD), Raman spectroscopy, scanning electron microscopy (SEM) and Energy Dispersive X‐ray Analysis (EDX). Combined experimental evidence would suggest that the elemental nanowires grow in the presence of the tin‐rich alloy Li2Sn5. The composites were tested as anodes for secondary lithium‐ion batteries and even for non‐optimised materials demonstrate appreciable and promising discharge capacities.
Synthesis and Characterization of Hybrid Pt/NiO/MWCNTs Electrocatalysts
Authors: Cheng I‐Ling , Chiou Yuh Jing , Lin Hong Ming
Published: July 2012

To search for more efficient and inexpensive electrocatalysts is one of the main research directions for the electrocatalytic application of direct liquid fuel cells. Nanohybrid Pt/NiO/MWCNTs are synthesized by impregnation and polyol methods. Two different series denoted as Pt/[NiO/MWCNTs (1:4)] and NiO/[Pt/MWCNTs (1:4)] are prepared. The sizes of the nanoparticles are 3‐7 nm and 10 nm for Pt and NiO, respectively. By observing the morphology images, NiO will aggregate more on Pt modified MWCNTs than those without Pt adding. The catalytic properties of these hybrid catalysts are characterized by methanol electro‐oxidation. The addition of 20 wt% NiO, before or after Pt synthesis, can better enhance the catalysis ability of Pt and help Pt catalyst convert CO in lower temperature. This study indicates the 10 wt% Pt/[NiO/MWCNTs (1:4)] catalyst has the best performance in electrocatalytic activity for methanol. The NiO is a cheaper material than other commonly used oxides; the novel hybrid catalysts are a promised candidate for the electrocatalytic application in DMFCs.
Unsymmetrical Squaraines Incorporating Cabazole as a Donor for Dye‐Sensitized Solar Cells
Authors: Li Jheng‐Ying , Lin Tsu‐Han , Chen Szu‐Chien , Wu Chun‐Guey
Published: July 2012

Three unsymmetrical squaraines, where the electron‐rich thiophene or bithiophene conjugated fragment was used to link unconventionally the squaraine core and carbazole (or methyl) group, were prepared. JYL‐SQ1 with thiophene as a donor and indoline‐carboxylic acid as an acceptor has λmax of 568 nm which is much longer than the general metal‐free organic dyes. Adding a carbazole unit in JYL‐SQ1 (forms JYL‐SQ2) can red‐shift the λmax to 603 nm. However, cabazole is not a strong donor (and indoline‐carboxylic acid is a weak acceptor) the LUMO of all three dyes are delocalized majorly on squaraine unit: the excited electrons of dye molecules injecting into TiO2 are not so efficiency, resulting in low short‐circuit current and conversion efficiency. The corresponding DSSC devices have the conversion efficiency of 0.71%, 2.59% and 2.22% for JYL‐SQ1, JYL‐SQ2 and THL‐SQ3, respectively.
SOCIAL SUPPORT DISPARITIES FOR CAREGIVERS OF AIDS‐ORPHANED CHILDREN IN SOUTH AFRICA
Authors: Kuo Caroline , Fitzgerald Jane , Operario Don , Casale Marisa
Published: July 2012

Drawing upon a sample of 1,599 adults caring for children in HIV‐endemic Umlazi Township in South Africa, this cross‐sectional survey investigated whether perceived social support varied among caregivers of AIDS‐orphaned children (n = 359) as compared with caregivers of children orphaned by other causes (n = 171) and caregivers of nonorphaned children (n = 1,069). Results of multivariate linear regressions indicate that caregivers of AIDS‐orphaned children reported significantly lower levels of social support compared with caregivers of other‐orphaned children and nonorphaned children independent of socio‐demographic covariates. Caregivers of other‐orphaned and nonorphaned children reported similar levels of social support. In terms of sources of support, all caregivers were more likely to draw support from family and significant others rather than friends. These findings indicate a need to develop interventions that can increase levels of social support for caregivers of AIDS‐orphaned children, particularly networks that include friends and significant others.
SELF‐STIGMA AND QUALITY OF LIFE AMONG PEOPLE WITH MENTAL ILLNESS WHO RECEIVE COMPULSORY COMMUNITY TREATMENT SERVICES
Authors: Livingston James
Published: July 2012

The present study was designed to examine the relationship between self‐stigma and quality of life over a one year time period for 71 people with mental illness who were receiving compulsory community mental health treatment. It was hypothesized that, over time, self‐stigma would have the direct effect of eroding quality of life among people with mental illness who were receiving compulsory community treatment; however, this relationship was not confirmed by the data. Although the cross‐sectional analyses revealed a moderate, negative relationship between self‐stigma and quality of life, the longitudinal analyses indicated that self‐stigma was not a significant predictor of quality of life. Among the variables measured in the current study, psychiatric symptom severity was the strongest predictor of quality of life.
PERCEIVED BEST FRIEND DELINQUENCY MODERATES THE LINK BETWEEN CONTEXTUAL RISK FACTORS AND JUVENILE DELINQUENCY
Authors: Fite Paula , Preddy Teresa , Vitulano Michael , Elkins Sara , Grassetti Stevie , Wimsatt Amber
Published: July 2012

The current study evaluated the effects of contextual risk factors (i.e., negative life events and neighborhood problems) and perceived best friend delinquency on child self‐reported delinquency. More specifically, the present study extended the literature by evaluating whether best friend delinquency moderated the effects of contextual risk factors on self‐reported delinquency in a community‐recruited sample of 147 school‐aged children (mean age = 8.22 years, standard deviation = 1.99; 54% male). Indeed, perceived best friend delinquency moderated these associations; however, the effect of best friend delinquency depended on the contextual risk factor. Findings and their implications are discussed.
Qualitative study of young, adult, and aged wistar rats temporomandibular synovial membrane employing light, scanning, and transmission electron microscopy
Authors: Duro Christiano Cony , Ciena Adriano Polican , De Almeida Sonia Regina Yokomizo , Da Silva Righetti Marta Maria , De Freitas Grisolia Débora , Issa João Paulo Mardegan , Da Silva Marcelo Cavenaghi Pereira , Watanabe Ii‐sei
Published: July 2012

The aim of this study was to analyze the rat temporomandibular joint (TMJ) synovial membrane at different ages using light, scanning, and transmission electron microscopy. Under light microscopic analysis, the TMJ structures were observed such as condyle, capsule, disk, the synovial membrane collagen type, and cells distribution. In the scanning electron microscopy, the synovial membrane surface exhibited a smooth aspect in young animals and there was an increase with ageing in the number of folds. The transmission electron microscopic analysis showed more synoviocytes in the synovial layer in the young group and still a great number of vesicles and cisterns dilation of rough endoplasmic reticulum in the aged group. In the three groups, a dense layer of collagen fibers in the synovial layer and cytoplasmic extensions were clearly seen. It was possible to conclude that synovial membrane structures in aged group showed alterations contributing to the decrease in joint lubrication and in the sliding between disk and joint surfaces. These characteristic will reflect in biomechanics of chewing, and may cause the TMJ disorders, currently observed in clinical processes. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.
Morphology of immature stages of Dohrniphora cornuta (Bigot) (Diptera: Phoridae)
Authors: Feng Dian‐Xing , Liu Guang‐Chun
Published: July 2012

Morphology of all larval instars and puparium of Dohrniphora cornuta (Bigot), a most common phorid fly species indoors in China, is presented using scanning electron microscopy. The first instar larva was composed of 12 segments, each of segments 3–11 with six slender tubercles situated dorsally, dorsolaterally, and laterally in transverse row. These tubercles divided into two segments, of which the basal one was smooth, and the brush‐shaped distal one was comprised of a cluster of fine spines. Antennae and maxillary palp complex were visible. Two slits could be seen at the posterior spiracle. Besides the presence of anterior spiracle, the tubercles of second instar became stouter than those of first instar and were covered by numerous long bristles from the base to top. The posterior spiracle contained four slits. Third larval instar was similar to second instar. The bubble membrane comprised of ≈120 globules with a pointed tip on their top presented at the segment 5 of third instar larvae. Puparia showed a retracted cephalic region and a pair of distinct pupal respiratory horns on the dorsum. The respiratory horns were long and bore numerous branches from base to apex. The apex of branch with two longitudinal slits was relatively broad and curled dorsally. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.
Effects of irrigation solutions on the surface of protaper instruments: A microscopy study
Authors: Sağlam Baran Can , Koçak Sibel , Koçak Mustafa Murat , Topuz ÖZgür
Published: July 2012

The aim of this study was to evaluate the effects of sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), and mixture of tetracycline, citric acid, and detergent (MTAD) solutions on the surfaces of nickel titanium (NiTi) rotary files with scanning electron microscopy (SEM) and atomic force microscopy (AFM). Irrigation solutions including 2.5% NaOCl, 5% NaOCl, 2% CHX, and MTAD were used. Four new ProTaper rotary NiTi files (F3) were immersed in each four irrigation solutions for 10 min, separately. One untreated NiTi file was used as a control specimen. The surface analysis was performed with SEM and AFM. The surface analysis in AFM was performed on 12 different regions located between first and second millimeters from the tip. SEM images were taken with different magnifications. No surface alteration was recorded under SEM evaluation. AFM revealed that the root mean square (RMS) values of all treated specimens were statistically higher than the control sample (P < 0.05). The sample which was treated with CHX showed lowest RMS values in test groups. All tested solutions caused surface alterations. CHX demonstrated limited surface alterations when compared to the other tested solutions. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.
Seasonal Variation in Sensitivity of the Photoperiodic Response System in the Subtropical Tree Sparrow (Passer montanus)
Authors: Dixit Anand S. , Singh Namram S.
Published: July 2012

We investigated seasonal variations in response to photoperiods in subtropical tree sparrow (Passer montanus), by examining the effects of long and short days on stimulation of response and termination of refractoriness, respectively. We also assessed whether photoperiodic effects were sex dependent. In one study, wild sparrows were transferred in each month of the year to artificial long days (14L/10D) for 12 weeks. Birds transferred from November to March (female) or April (male) showed gradual increase in gonadal growth and darkening of bill color, while those transferred from April (female) or May (male) to July underwent gradual regression in the above responses. Moult in the wing primaries and body feathers progressed with gonadal regression and the birds transferred from April/May to October exhibited gradual increase and decrease in feathers moult. In another study, 6 weeks of short day (9L/15D) exposure could recover responsivity to long days in refractory birds. Male and female birds responded almost in similar fashion with some variations. Overall, our results show a gradual change over seasons in responsiveness of the endogenous response system to stimulatory effects of long day length. They suggest roles of both long and short day lengths in regulation of seasonal cycles in subtropical tree sparrows. J. Exp. Zool. 317A:488–498, 2012. © 2012 Wiley Periodicals, Inc.
Influence of Temperature, Hypercapnia, and Development on the Relative Expression of Different Hemocyanin Isoforms in the Common Cuttlefish Sepia officinalis
Authors: Strobel Anneli , Hu Marian Y.A. , Gutowska Magdalena A. , Lieb Bernhard , Lucassen Magnus , Melzner Frank , Pörtner Hans O. , Mark Felix C.
Published: July 2012

The cuttlefish Sepia officinalis expresses several hemocyanin isoforms with potentially different pH optima, indicating their reliance on efficient pH regulation in the blood. Ongoing ocean warming and acidification could influence the oxygen‐binding properties of respiratory pigments in ectothermic marine invertebrates. This study examined whether S. officinalis differentially expresses individual hemocyanin isoforms to maintain optimal oxygen transport during development and acclimation to elevated seawater pCO2 and temperature. Using quantitative PCR, we measured relative mRNA expression levels of three different hemocyanin isoforms in several ontogenetic stages (embryos, hatchlings, juveniles, and adults), under different temperatures and elevated seawater pCO2. Our results indicate moderately altered hemocyanin expression in all embryonic stages acclimated to higher pCO2, while hemocyanin expression in hatchlings and juveniles remained unaffected. During the course of development, total hemocyanin expression increased independently of pCO2 or thermal acclimation status. Expression of isoform 3 is reported for the first time in a cephalopod in this study and was found to be generally low but highest in the embryonic stages (0.2% of total expression). Despite variable hemocyanin expression, hemolymph total protein concentrations remained constant in the experimental groups. Our data provide first evidence that ontogeny has a stronger influence on hemocyanin isoform expression than the environmental conditions chosen, and they suggest that hemocyanin protein abundance in response to thermal acclimation is regulated by post‐transcriptional/translational rather than by transcriptional modifications. J. Exp. Zool. 317A:511–523, 2012. © 2012 Wiley Periodicals, Inc.
The Function and Developmental Expression of Alternatively Spliced Isoforms of Amphioxus and Xenopus laevis Pax2/5/8 Genes: Revealing Divergence at the Invertebrate to Vertebrate Transition
Authors: Short Stephen , Kozmik Zbynek , Holland Linda Z.
Published: July 2012

Pax genes encode highly conserved transcription factors vital for metazoan development. Pax transcripts, particularly those in Group II (Pax2/5/8), are extensively alternatively spliced. This study compares the transcriptional activation capacity and developmental stage‐specific expression of major isoforms of Group II Pax proteins in amphioxus (Branchiostoma floridae) and in Xenopus laevis. The comparison reveals considerable divergence of splice forms between the lineages, with the X. laevis Group II Pax genes (Pax2, Pax5, and Pax8) possessing a greater repertoire of regulated and functionally distinct splice forms than the single amphioxus gene (Pax2/5/8). Surprisingly, some apparently conserved splice forms are expressed at quite different levels during development in the two organisms and present different capacities to activate transcription. However, despite this divergence, the combinatorial transcriptional activation capacity of the isoforms present in early X. laevis and amphioxus development are broadly similar. This suggests that the some of the conserved functional roles, implied by the expression of Group II Pax genes in homologous tissues of amphioxus and X. laevis embryos, may depend upon the combination of isoforms expressed in a particular tissue at a particular time in development. Thus, during early development, the evolutionary constraint on the net effect of several isoforms co‐expressed in a given tissue may be more strict than that on specific isoforms. This flexibility may facilitate the appearance of new exons and splicing patterns in the vertebrate duplicates, leading to isoforms with subtly distinct functions critical to the subsequent development of vertebrate‐specific cell types and structures. J. Exp. Zool. (Mol. Dev. Evol.) 318B:555–571, 2012. © 2012 Wiley Periodicals, Inc.