bluuebunny/crossref_metadata_2025 huggingface dataset:
Photochromic Oxazines with Extended Conjugation
Authors: Petersen Michael Åxman , Deniz Erhan , Nielsen Mogens Brøndsted , Sortino Salvatore , Raymo Françisco M.
Published: July 2009

We synthesized four compounds with indole and benzooxazine fragments fused in their molecular skeleton and differing in the substituent in the para position, relative to the oxygen atom, of their phenoxy chromophore. This particular substituent extends the conjugation of the phenoxy chromophore and shifts its absorption bathochromically by up to 60 nm, relative to a parent compound with a 4‐nitrophenoxy group. The 1,3‐oxazine ring of all compounds opens upon addition of base to generate a hemiaminal incorporating a phenolate chromophore. Once again, the substituents on this fragment shift its absorption bathochromically by up to 60 nm, relative to the parent compound. Upon laser excitation at a wavelength within the absorption range of the phenoxy chromophore, the 1,3‐oxazine ring of the compound incorporating a 4‐nitrophenyl substituent opens in less than 6 ns to generate a zwitterionic isomer with a quantum yield of 0.11 in acetonitrile. Under these conditions, the photogenerated isomer has a lifetime of 29 ns and reverts spontaneously to the original species with first‐order kinetics. Furthermore, this photochromic system tolerates hundreds of switching cycles with no sign of degradation even in the presence of molecular oxygen. However, the excitation dynamics of the other three compounds, incorporating a 4‐nitrobiphenyl, 4‐nitrostyryl or 4‐nitrophenylethynyl substituent, are dominated by intersystem crossing. Consistently, the corresponding transient spectra reveal predominantly triplet–triplet absorptions. Thus, our studies demonstrate that the excitation wavelength and color of this class of photochromic compounds can be regulated by extending the conjugation of their phenoxy fragment with negligible influence on the photochromic performance only if the structural modification does not encourage intersystem crossing. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Efficient Rhodium‐Catalyzed Conjugate Addition of Arylboronic Acids to Unsaturated Furano Esters for the Highly Stereoselective Synthesis of Four Natural Trisubstituted Furanolignans
Authors: Mondière Aurélie , Pousse Guillaume , Bouyssi Didier , Balme Geneviève
Published: July 2009

Four natural lignans, (±)‐dihydrosesamin (1a), (±)‐lariciresinol methyl ether (1b), (±)‐sanshodiol methyl ether (1c) and (±)‐acuminatin methyl ether (1d), were prepared stereoselectively in five steps from a 4‐(arylmethylene)‐2‐methoxytetrahydrofuran derivative obtained by a MCR reaction. The key step of this synthesis is the microwave‐assisted stereoselective addition of a boronic acid (Hayashi–Miyaura reaction) to a 4‐ethoxycarbonyldihydrofuran, generating three contiguous stereogenic centers with an excellent diastereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Why some women can feel more, and others less, attractive after exposure to attractive targets: The role of social comparison orientation
Authors: Bosch A. Zwenneke , Buunk Abraham P. , Siero Frans W. , Park Justin H.
Published: July 2009

As the tendency to compare oneself with others may be associated with the tendency to focus on similarities, we hypothesized that individual differences in social comparison orientation (SCO) may moderate the consequences of upward and downward comparisons. In Study 1, high comparers were found to focus more on similarities than low comparers, suggesting that high comparers are more likely to assimilate in general. In Study 2, SCO was found to be positively associated with mood following exposure to an attractive target, and negatively associated with mood following exposure to a less attractive target. In Studies 2 and 3, SCO was found to be positively associated with self‐evaluations of attractiveness following exposure to an attractive target and negatively associated with self‐evaluations of attractiveness following exposure to a less attractive target. These results indicate that research on the consequences of social comparison must attend to individual differences in SCO. Copyright © 2009 John Wiley & Sons, Ltd.
Tubulin polymerization‐promoting protein (TPPP/p25) is critical for oligodendrocyte differentiation
Authors: Lehotzky Attila , Lau Pierre , Tőkési Natália , Muja Naser , Hudson Lynn D. , Ovádi Judit
Published: July 2009

TPPP/p25, a recently identified tubulin polymerization‐promoting protein (TPPP), is expressed mainly in myelinating oligodendrocytes of the CNS. Here, we show that TPPP/p25 is strongly upregulated during the differentiation of primary oligodendrocyte cells as well as the CG‐4 cell line. The microRNA expression profile of CG‐4 cells before and after induction of differentiation was established and revealed differential regulation of a limited subset of microRNAs. miR‐206, a microRNA predicted to target TPPP/p25, was not detected in oligodendrocytes. Overexpression of miR‐206 led to downregulation of TPPP/p25 resulting in inhibition of differentiation. Transfection of siRNAs against TPPP/p25 also inhibited cell differentiation and promoted cell proliferation, providing evidence for an important role of TPPP/p25 during oligodendrogenesis. These results support an essential role for TPPP/p25 in oligodendrocyte differentiation likely via rearrangement of the microtubule system during the process elongation prior to the onset of myelination. © 2009 Wiley‐Liss, Inc.
Different astroglia permissivity controls the migration of olfactory bulb interneuron precursors
Authors: García‐Marqués Jorge , De Carlos Juan A. , Greer Charles A. , López‐Mascaraque Laura
Published: July 2009

The rostral migratory stream (RMS) is a well defined migratory pathway for precursors of olfactory bulb (OB) interneurons. Throughout the RMS an intense astroglial matrix surrounds the migratory cells. However, it is not clear to what extent the astroglial matrix participates in migration. Here, we have analyzed the migratory behavior of neuroblasts cultured on monolayers of astrocytes isolated from areas that are permissive (RMS and OB) and nonpermissive (cortex and adjacent cortical areas) to migration. Our results demonstrate robust neuroblast migration when RMS‐explants are cultured on OB or RMS‐astrocytes, in contrast to their behavior on astroglia derived from nonpermissive areas. These differences, mediated by astrocyte‐derived nonsoluble factors, are related to the overexpression of extracellular matrix and cell adhesion molecules, as revealed by real‐time qRT‐PCR. Our results show that astroglia heterogeneity could play a significant role in migration within the RMS and in cell detachment in the OB. © 2009 Wiley‐Liss, Inc.
The —308 (G/A) single nucleotide polymorphism in the TNF‐α gene and the risk of major depression in the elderly
Authors: Cerri Anna Paola , Arosio Beatrice , Viazzoli Chiara , Confalonieri Roberto , Vergani Carlo , Annoni Giorgio
Published: July 2009

Objective

The immune system (IS) plays a key role in the mechanisms underlying major depression (MD) and pro‐inflammatory cytokines seem to be particularly involved in the pathogenesis of the disease. There is growing evidence of a relationship between commonly studied single nucleotide polymorphisms (SNPs) in cytokine genes and an increased risk of MD.

The aim of our study was to investigate the association between the −308(G/A) SNP in the tumour necrosis factor‐α (TNF‐α) gene and late‐life MD in elderly people without dementia.

Methods

Blood samples were obtained from 50 subjects enrolled at the Geriatric Department of the San Gerardo Hospital in Monza, Italy, after screening with the geriatric depression scale (GDS ≥ 15) and mini‐mental state evaluation (MMSE ≥ 24). The −308 (G/A) SNP was genotyped by SSP‐PCR amplification. Two hundred and forty age‐matched healthy volunteers were taken as the control group.

Results

Genotype and allele distributions in patients with MD were significantly different from those of the controls. In subjects affected by MD we found a higher percentage of the GG genotype (84 vs. 68,3%; p = 0.007) and thus of the G allele (92 vs. 81,9%; p = 0.05).

The GG genotype was associated with a greater risk of developing the disease (OR 2.433, CI 1.09–5.43).

Conclusions

Our study suggests that the −308 (G/A) polymorphism in the TNF‐α gene could play a role in determining susceptibility to MD. An activation of the TNF‐α system could contribute to the development of MD in the elderly. Copyright © 2009 John Wiley & Sons, Ltd.
Strength of shoulder during one‐handed pushing in constrained conditions
Authors: Gielo‐Perczak Krystyna
Published: July 2009

This study hypothesizes that, by isolating the influences of contact surface friction, back foot support, and forward‐leaning body posture during pushing, the magnitude of recorded strength will be a closer estimate of physical capabilities of the shoulder. The shoulder strength of twelve participants during one‐handed pushing in constrained conditions in the coronal (frontal) plane, in a range from 5 to 30 degrees, was correlated with the anthropometric measures and two anatomical parameters of the shoulder joint. The data indicated that the acceptable loads at the handle for all the participants were lower than the recommended standards. Right arm length had the highest correlation coefficient with shoulder strength among anthropometric data, and the radius of the humerus bone among anatomical parameters. The findings from this study of one‐handed pushing will be used to help modify existing physical strength standards in an effort to reduce the high frequency of recorded shoulder injuries. © 2009 Wiley Periodicals, Inc.
Investigating the impact of the Chi‐Chi earthquake on the occurrence of debris flows using artificial neural networks
Authors: Chang Fi‐John , Chiang Yen‐Ming , Lee Wong‐Shuo
Published: July 2009

Debris flows have caused enormous losses of property and human life in Taiwan during the last two decades. An efficient and reliable method for predicting the occurrence of debris flows is required. The major goal of this study is to explore the impact of the Chi‐Chi earthquake on the occurrence of debris flows by applying the artificial neural network (ANN) that takes both hydrological and geomorphologic influences into account. The Chen‐Yu‐Lan River watershed, which is located in central Taiwan, is chosen for evaluating the critical rainfall triggering debris flows. A total of 1151 data sets were collected for calibrating model parameters with two training strategies. Significant differences before and after the earthquake have been found: (1) The size of landslide area is proportioned to the occurrence of debris flows; (2) the amount of critical rainfall required for triggering debris flows has reduced significantly, about half of the original critical rainfall in the study case; and (3) the frequency of the occurrence of debris flows is largely increased. The overall accuracy of model prediction in testing phase has reached 96·5%; moreover, the accuracy of occurrence prediction is largely increased from 24 to 80% as the network trained with data from before the Chi‐Chi earthquake sets and with data from the lumped before and after the earthquake sets. The results demonstrated that the ANN is capable of learning the complex mechanism of debris flows and producing satisfactory predictions. Copyright © 2009 John Wiley & Sons, Ltd.
The dynamics of floods in the Bolivian Amazon Basin
Authors: Bourrel L. , Phillips L. , Moreau S.
Published: July 2009

In 1997, a study was initiated by IRD, Bolivia to analyse the dynamics of floods in the Bolivian Amazon, which commonly affect an area of 100 000 to 150 000 km2 for about 4 months of the year. This region is characterized by vast isolated areas with difficult access and is continuously covered by clouds in the wet season. For these reasons, this hydrological study depends heavily on the use of remote sensing, and particularly radar data, for flood monitoring and the identification of areas at risk of inundation. This article presents preliminary results obtained in the Trinidad area, around the Mamoré River, using LANDSAT, ERS and RADARSAT radar data from dry, wet and flood seasons (collected between 1996 and 1998), and water level and, hydrometeorological data obtained from the upper and lower parts of the Mamoré basin. After characterizing the annual flood cycle within the study area, a TM colour composite (to map the vegetation) and a radar colour composite (multi‐temporal), are used to evaluate the potential contribution of microwave data (RADARSAT and ERS) for mapping the extent of flooding at both the regional (all the flood plain) and the local scale (around the city of Trinidad). Copyright © 2009 John Wiley & Sons, Ltd.
Epistatic interactions govern chemically‐induced lung tumor susceptibility and Kras mutation site in murine C57BL/6J‐ChrA/J chromosome substitution strains
Authors: Dwyer‐Nield Lori D. , McQuillan Jay , Hill‐Baskin Annie , Radcliffe Richard A. , You Ming , Nadeau Joseph H. , Malkinson Alvin M.
Published: July 2009

Cancer susceptibility results from interactions between sensitivity and resistance alleles. We employed murine chromosome substitution strains to study how resistance alleles affected sensitive alleles during chemically‐induced lung carcinogenesis. The C57BL/6J‐Chr#A/J strains, constructed by selectively breeding sensitive A/J and resistant C57BL/6J (B6) mice, each contain one pair of A/J chromosomes within an otherwise B6 genome. Pas1, the major locus responsible for this differential strain response to urethane carcinogenesis, resides on Chr 6, but C57BL/6J‐Chr6A/J mice (hereafter CSS‐6) developed few tumors following a single urethane injection, which demonstrates epistatic interactions with other B6 alleles. CSS6 mice developed dozens of lung tumors after chronic urethane exposure, however, indicating that these epistatic interactions could be overcome by repeated carcinogen administration. Unlike A/J, but similar to B6 mice, CSS6 mice were resistant to lung carcinogenesis induced by 3‐methylcholanthrene (MCA). Tumor multiplicity increased if BHT administration followed urethane exposure, showing that a Chr 6 gene(s) regulates sensitivity to chemically‐induced tumor promotion. Unlike A/J tumors (predominantly codon 61 A→T transversions), Kras mutations in tumors induced by urethane in CSS‐6 mice were similar to B6 tumors (codon 61 A→G transitions). DNA repair genes not located on Chr 6 may determine the nature of Kras mutations. CSS‐6 mice are a valuable resource for testing the ability of candidate genes to modulate lung carcinogenesis.
DNA methylation analysis in liquid‐based cytology for cervical cancer screening
Authors: Apostolidou Sophia , Hadwin Richard , Burnell Matthew , Jones Allison , Baff Donna , Pyndiah Nitisha , Mould Tim , Jacobs Ian J. , Beddows Simon , Kocjan Gabrijela , Widschwendter Martin
Published: July 2009

Cervical cancer is the second most common type of cancer in women worldwide. Preinvasive disease can be detected by cervical cytology. All currently available cytology technologies rely on the visual analysis of exfoliated cells from the uterine cervix. Improvement of conventional cytological screening has been proposed by the introduction of molecular‐based markers applied to liquid‐based cytology (LBC), the suspension of cells collected from the cervix. DNA methylation changes occur very early in carcinogenesis and identification of appropriate DNA methylation markers in such samples should be able to distinguish high‐grade squamous intraepithelial lesions (HSIL) from nonspecific cytology changes and the normal cervix. To address this potential, we have undertaken a proof‐of‐principle study of methylation status of LBC samples from HSIL cytology cases compared against matched normal controls. Using quantitative methylation‐specific PCR on 28 genes, we found SOX1, HOXA11 and CADM1 to significantly discriminate between the groups analyzed (p < 0.01). Area under the receiver operating characteristic (ROC) curve (AUC) demonstrated that methylation of SOX1, HOXA11 and CADM1 could discriminate between HSIL cases and controls with high sensitivity and specificity (AUC 0.910, 0.844 and 0.760, respectively). The results were further validated in an independent set. This proof‐of‐principle study is the first to validate the results in an independent case/control set and presents HOXA11, a gene that is important for cervical development, as a potentially useful DNA marker in LBC samples. Further assessment of these preliminary estimates will need to be performed in a larger cohort to confirm clinical utility. © 2009 UICC
Frequency of and variables associated with the EGFR mutation and its subtypes
Authors: Tanaka Tomoaki , Matsuoka Masaru , Sutani Akihisa , Gemma Akihiko , Maemondo Makoto , Inoue Akira , Okinaga Shoji , Nagashima Makoto , Oizumi Satoshi , Uematsu Kazutsugu , Nagai Yoshiaki , Moriyama Gaku , Miyazawa Hitoshi , Ikebuchi Kenji , Morita Satoshi , Kobayashi Kunihiko , Hagiwara Koichi
Published: July 2009

Mutation in the epidermal growth factor receptor (EGFR) is frequently seen in non‐small cell lung cancers (NSCLCs), especially in Asian females with adenocarcinoma. The frequency of mutation and the factors associated requires to be elucidated by analyzing a large number of consecutive clinical samples. We summarized the result of the EGFR mutation analysis for 1,176 patients performed at the time of diagnosis or relapse. The PNA‐LNA PCR clamp, a highly sensitive detection method for the EGFR mutation, was employed. For fresh cases a portion of samples isolated to establish the diagnosis of lung cancer was used. For cases with a relapsed disease archival tissue were tested. The variables associated with the EGFR mutation after removing the confound factors were investigated by the logistic analysis using the samples collected in our university (n = 308) where detailed information on patients were available. The frequency of the EGFR mutation and its subtypes were investigated using all samples (n = 1,176). The EGFR mutation was significantly associated with adenocarcinoma (p = 0.006) and light‐smoking (p < 0.0001), but not gender. The deletions in exon 19 were more frequently associated with male gender while exon 21 deletions were with female gender (p = 0.0011). The overall frequency of the EGFR mutation was 31%. Our result suggests that the female predominance in the EGFR mutation rate is a reflection of a higher frequency of adenocarcinoma in females. The gender difference in the mutation subtypes may provide a clue for the mechanism of the occurrence of the EGFR mutation.
Celecoxib reduces the effects of acute and chronic UVB exposure in mice treated with therapeutically relevant immunosuppressive drugs
Authors: Wulff Brian C. , Thomas‐Ahner Jennifer M. , Schick Jonathan S. , Oberyszyn Tatiana M.
Published: July 2009

Solid organ transplant recipients have a greatly increased risk for the development of non‐melanoma skin cancers. We have previously shown in our mouse model that sirolimus given in combination with cyclosporine A resulted in fewer and smaller tumors than cyclosporine A alone. In the current study, we tested the hypothesis that an anti‐inflammatory agent celecoxib applied topically after UVB exposure would further reduce UVB induced skin cancer in mice treated with cyclosporine A and sirolimus. The effect of celecoxib treatment on acute inflammation, initiation/promotion and tumor development was examined through a set of four experiments. Delayed tumor onset was observed in both tumor development experiments. Reduced tumor size and number compared to vehicle was observed when CX was administered concurrently with UVB and when CX was administered after cessation of UVB treatments, respectively. Prostaglandin E2 was confirmed to be significantly reduced in the dorsal skin of mice concurrently treated with immunosuppressants, CX and UVB for 13 weeks, suggesting a reduction in the inflammatory response could be the mechanism by which CX reduced tumorigenesis. Furthermore, topical celecoxib treatment following acute UVB exposure reduced dermal neutrophil number and activity compared to vehicle. In all of these experiments, unirradiated and vehicle treated mice were utilized as controls. In conclusion, these data suggest that even in the presence of cyclosporine A and sirolimus, topical celecoxib treatment can result in reduced inflammation, tumor number and size; properties which may be beneficial in the therapeutic reduction of skin cancer development in solid organ transplant recipients.
Endocrine resistance associated with activated ErbB system in breast cancer cells is reversed by inhibiting MAPK or PI3K/Akt signaling pathways
Authors: Ghayad Sandra E. , Vendrell Julie A. , Larbi Sabrina Ben , Dumontet Charles , Bieche Ivan , Cohen Pascale A.
Published: July 2009

Endocrine therapy resistance is one of the main challenges in the treatment of estrogen receptor positive (ER+) breast cancer patients. This study showed that two ER+ human breast carcinoma cell lines derived from MCF‐7 (MVLN cells) that have acquired under OH‐Tamoxifen selection two distinct phenotypes of endocrine resistance both displayed constitutive activation of the PI3K/Akt and MAPK pathways. Aberrant expression and activation of the ErbB system (phospho‐EGFR, phospho‐ErbB2, phospho‐ErbB3, over‐expression of ErbB4 and over‐expression of several ErbB ligands) were also observed in the two resistant cell lines, suggesting the existence of an autocrine loop leading to constitutive activation of MAPK and PI3K/Akt survival pathways. The recent clinical use of specific signal transduction inhibitors is one of the most promising therapeutic approaches in breast cancers. The MEK inhibitor PD98059 and the PI3K inhibitor LY294002 were both able to enhance the cytostatic effect of OH‐Tamoxifen or fulvestrant on MVLN sensitive cells. In the two resistant cell lines, inhibition of the MAPK or the PI3K/Akt pathways associated with endocrine therapy was sufficient to reverse OH‐Tamoxifen or fulvestrant resistance. Investigating the effect of a combination of both inhibitors on the reversion of OH‐Tamoxifen and fulvestrant resistance in the two resistant cell lines suggested that, in clinical practice, a strategy combining the two inhibitors would be the best approach to target the different endocrine resistance phenotypes possibly present in a tumor. In conclusion, the combination of MAPK and PI3K inhibitors represents a promising strategy to overcome endocrine therapy resistance in ER+ breast cancer patients.
Selective osteopontin knockdown exerts anti‐tumoral activity in a human glioblastoma model
Authors: Lamour Virginie , Le Mercier Marie , Lefranc Florence , Hagedorn Martin , Javerzat Sophie , Bikfalvi Andreas , Kiss Robert , Castronovo Vincent , Bellahcène Akeila
Published: July 2009

Osteopontin (OPN), a member of the SIBLING (Small Integrin‐Binding LIgand N‐linked Glycoprotein) family, is overexpressed in human glioblastoma. Higher levels of OPN expression correlate with increased tumor grade and enhanced migratory capacity of tumor cells. Based on these observations, we explored the possibility that knocking down OPN expression in glioblastoma cells could exert an anti‐tumoral activity using an avian in vivo glioblastoma model that mimics closely human gliobastoma. Human U87‐MG glioma cells transfected with specific anti‐OPN small interfering RNAs (siRNAs) were grafted onto the chicken chorio‐allantoic membrane (CAM). OPN‐deficient U87‐MG cells gave rise to tumors that were significantly smaller than tumors formed from untransfected cells (paired t‐test, p < 0.05). Accordingly, the amount of proliferating cells in OPN‐deficient tumors showed a six‐fold reduction when compared to control tumors. However, OPN inhibition did not affect significantly tumor‐associated angiogenesis. In vitro, OPN‐silenced U87‐MG and U373‐MG cells showed decreased motility and migration. This is the first demonstration that OPN inhibition blocks glioma tumor growth, making this invasion‐related protein an attractive target for glioma therapy.
Evaluation of photo‐crosslinked fibrinogen as a rapid and strong tissue adhesive
Authors: Elvin C. M. , Danon S. J. , Brownlee A. G. , White J. F. , Hickey M. , Liyou N. E. , Edwards G. A. , Ramshaw J. A. M. , Werkmeister J. A.
Published: July 2009

Tissue adhesives and sealants are commonly used in surgery either as an adjunct to, or replacement for, sutures. Previously, we have shown that fibrinogen can be crosslinked rapidly to give a high‐strength bond in the presence of a rutheniumII complex, a persulfate and irradiation with visible light, and that the crosslinked fibrinogen is nontoxic to cells in vitro. This approach addresses limitations to current fibrin sealants that typically have relatively slow curing times and low bond strengths. In the present study, we have evaluated the efficacy and safety of this new biological scaffold sealant in various animal models. When placed as solid implants into rats, the crosslinked fibrinogen persisted for at least 8 weeks but was fully resorbed by 18 weeks with minimal inflammatory responses. When used as a tissue adhesive for repair of skin incisions in rats or as an arterial haemostat in pig, the photo‐crosslinked fibrinogen sealed tissue or arrested bleeding within 20 s of application. For the skin incisions, the fibrinogen sealant promoted rapid tissue vascularization and cellular infiltration with no adverse foreign body cell generation. New collagen deposition occurred and with time the matrix had remodelled to acquire large mature collagen fiber bundles which were accompanied by maximum regenerated tensile strength. This biomaterial system may find useful applications in surgical procedures where rapid curing and/or high strength tissue sealing is required. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Density functional theory study of the free and tetraprotonated spheroidal macrotricyclic ligands and the complexes with halide anions: F−, Cl−, Br−
Authors: Zheng Xiaoyan , Wang Xueye , Yi Shanfeng , Wang Nuanqing , Peng Yueming
Published: July 2009

Theoretical studies of the macrotricyclic tetramine hexaether (SC), its tetraprotonated form SC‐4H+, and the corresponding complexes X−⊂SC‐4H+ (This expression represents the structural properties of the halide inclusion complex formed though the free ligand SC‐4H+ and the halide anion X−: the spherical halide anion X− is held by a tetrahedral array of +NH···X− hydrogen bonds inside the intramolecular cavity of the tetraprotonated form SC‐4H+) of SC‐4H+ with the halide anions: F−, Cl−, and Br− have been performed using density functional theory (DFT) with B3LYP/6‐31G method implemented in the Gaussian 03 program package. The optimized geometric structures obtained from DFT calculations are used to perform Natural Bond Orbital (NBO) analysis. The three main types of hydrogen bonds +NH···F−, +NH···Cl−, and +NH···Br− are investigated. The results indicate that hydrogen bonding interactions are dominant and the halide anions: F−, Cl−, and Br− offer lone pair electrons to the contacting σ* (NH) antibond orbital of SC‐4H+. For all the structures, the most pronounced changes in geometric parameters upon interaction are observed in the proton‐donor molecule. The intermolecular interaction energies are predicted by using B3LYP/6‐31G methods with basis set superposition error (BSSE) and zero‐point energy (ZPE) correction. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
New angle‐dependent potential energy function for backbone–backbone hydrogen bond in protein–protein interactions
Authors: Choi Hwanho , Kang Hongsuk , Park Hwangseo
Published: July 2009

Backbone–backbone hydrogen bonds (BBHBs) are one of the most abundant interactions at the interface of protein–protein complex. Here, we propose an angle‐dependent potential energy function for BBHB based on density functional theory (DFT) calculations and the operation of a genetic algorithm to find the optimal parameters in the potential energy function. The angular part of the energy funtion is assumed to be the product of the power series of sine and cosine functions with respect to the two angles associated with BBHB. Two radial functions are taken into account in this study: Morse and Leonard‐Jones 12‐10 potential functions. Of these two functions under consideration, the former is found to be more accurate than the latter in terms of predicting the binding energies obtained from DFT calculations. The new HB potential function also compares well with the knowledge‐based potential derived by applying Boltzmann statistics for a variety of protein–protein complexes in protein data bank. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Ruptured intramuscular ganglion cyst in the gastrocnemius medialis muscle: Sonographic appearance
Authors: Park Soonchan , Jin Wook , Chun Young Soo , Park So Young , Kim Hyun Cheol , Kim Gou Young , Park Ji Seon , Ryu Kyung Nam
Published: July 2009

We report the case of a 55‐year‐old woman who presented with a severe pain and a mass in the proximal portion of the medial calf. On sonography, the lesion appeared as a poorly defined hypoechoic lesion with interspersed muscle bundles. A total excision of the lesion was performed. On microscopic examination, the specimen demonstrated cystic lesions surrounded by fibrous walls within the muscle bundles. A ruptured intramuscular ganglion cyst diagnosis was made based on the histopathologic findings. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Can the smallest depth of ascitic fluid on sonograms predict the amount of drainable fluid?
Authors: Irshad Abid , Ackerman Susan J. , Anis Munazza , Campbell Amy S. , Hashmi Atif , Baker Nathaniel L.
Published: July 2009

Purpose

To investigate the correlation between the ‘smallest fluid depth’ (SFD) measured on sonography (US) at the ‘paracentesis pocket’ with the amount of fluid drained in patients referred for US‐guided large‐volume paracentesis.

Methods

US examinations performed to guide 60 paracenteses in 29 patients with large‐volume ascites were reviewed and the SFD measured at the site of the paracentesis. The SFD was measured from the most superficial bowel loop to the abdominal wall. The SFD measurements were compared with the drained fluid volume (DFV) measurements.

Results

The average DFV per paracentesis was 5.2 L with an average SFD measurement of 5.4 cm. For every 1‐cm increase in the measured SFD, there was an average 1‐L increase in the DFV. After applying this relationship to the measured depth in each case, the comparison between the estimated fluid volume (EFV) on US and the DFV demonstrated a <1‐L difference in 38 of 60 paracenteses (63.3%) and a <2‐L difference in 51 of 60 paracenteses (85%).

Conclusion

The SFD measured at the site of paracentesis shows a correlation with the drained fluid volume and can be used for fluid volume estimation on US. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Synthesis of a series of carbon‐14 labelled 4‐aminoquinazolines and quinazolin‐4 (3H)‐ones
Authors: Saemian Nader , Arjomandi Omid Khalili , Shirvani Gholamhossein
Published: July 2009

4‐Aminoquinazolines and quinazolin‐4 (3H)‐ones, both labelled with carbon‐14 in the 4‐position, were prepared from 2‐aminobenzonitrile‐[cyano‐14C] and 2‐aminobenzoic acid‐[carboxy ‐14C] or 2‐amino‐ benzamide‐[carboxy ‐14C], respectively, using rapid, one‐pot procedures under microwave enhanced conditions. Copyright © 2009 John Wiley & Sons, Ltd.
Mass spectrometric study of oligourea macrocycles and their anion binding behavior
Authors: Becherer Tobias , Meshcheryakov Denys , Springer Andreas , Böhmer Volker , Schalley Christoph A.
Published: July 2009

Two series, one of tris‐urea macrocycles and another of hexakis‐urea macrocycles, are examined by (tandem) Fourier‐transform ion cyclotron resonance (FTICR) mass spectrometry with respect to their fragmentation patterns and anion binding properties. All macrocycles are based on two different building blocks, one of which is a very rigid xanthene unit and the other one is a more flexible diphenyl ether. The composition and the sequence of these units thus determine their flexibility. During the fragmentation of deprotonated oligourea macrocycles in the gas phase, one urea NCO bond is cleaved followed by a scrambling reaction within the macrocycle structure. Consequently, fragments are observed that deviate from those that would be expected from the sequence of the subunits. Interesting anion binding properties involve the simultaneous recognition of two chloride anions by one of the hexakis‐urea macrocycles, whose flexibility allows this host to form a double‐helical structure. Flexibility also determines which of the hexameric receptors bears a high sulfate affinity. The interaction energy between some of the macrocycles and sulfate is high enough to even stabilize the intrinsically unstable sulfate dianion. Copyright © 2009 John Wiley & Sons, Ltd.
Involvement of vH+‐ATPase in synaptic vesicle swelling
Authors: Shin Leah , Basi Nirukti , Jeremic Aleksandar , Lee Jin‐Sook , Cho Won Jin , Chen ZhiHui , Abu‐Hamdah Rania , Oupicky David , Jena Bhanu P.
Published: July 2009

Secretory vesicle swelling is central to cell secretion, but the underlying mechanism of vesicle swelling, particularly synaptic vesicles, is not completely understood. The Gαi3‐PLA2‐mediated involvement of water channel AQP‐1 in the regulation of secretory vesicle swelling in exocrine pancreas and the Gαo‐mediated AQP‐6 involvement in synaptic vesicle swelling in neurons have previously been reported. Furthermore, the role of vH+‐ATPase in neurotransmitter transport into synaptic vesicles has also been shown. Using nanometer‐scale precision measurements of isolated synaptic vesicles, the present study reports for the first time the involvement of vH+‐ATPase in GTP‐Gαo‐mediated synaptic vesicle swelling. Results from this study demonstrate that the GTP‐Gαo‐mediated vesicle swelling is vH+‐ATPase dependent and pH sensitive. Zeta potential measurements of isolated synaptic vesicles further demonstrate a bafilomycin‐sensitive vesicle acidification, following the GTP‐Gαo‐induced swelling stimulus. Water channels are bidirectional and the vH+‐ATPase inhibitor bafilomycin decreases both the volume of isolated synaptic vesicles and GTP‐mastoparan stimulated swelling, suggesting that vH+‐ATPase is upstream of AQP‐6, in the pathway leading from Gαo‐stimulated swelling of synaptic vesicles. Vesicle acidification is therefore a prerequisite for AQP‐6‐mediated gating of water into synaptic vesicles. © 2009 Wiley‐Liss, Inc.
Inhibition of neural activity depletes orexin from rat hypothalamic slice culture
Authors: Michinaga Shotaro , Hisatsune Akinori , Isohama Yoichiro , Katsuki Hiroshi
Published: July 2009

Orexins (hypocretins) are neuropeptides produced by a small population of hypothalamic neurons whose dysregulation may lead to narcolepsy, a neurological disorder characterized by disorganization of sleep and wakefulness. Excessive stimulation of the N‐methyl‐D‐aspartate (NMDA) subtype of glutamate receptors causes preferential loss of orexin neurons in the hypothalamus, whereas an adequate level of neuronal excitatory activities is generally known to be important for the maintenance of central neurons. By examining the effect of manipulation of neural activity, we found that 24–72 hr application of tetrodotoxin (TTX) caused a substantial decrease in the number of orexin‐immunoreactive neurons, but not of melanin‐concentrating hormone‐immunoreactive neurons, in hypothalamic slice culture. Similar results were obtained when neural activity was arrested by added extracellular Mg2+. Reduction of orexin expression by TTX and Mg2+ was also observed at mRNA level. The decrease of orexin‐immunoreactive neurons was attributable to depletion of orexin, because it was reversible after washout of TTX or elevated extracellular Mg2+ and was not associated with induction of cell death. Blockers of voltage‐dependent Ca2+ channels as well as of NMDA receptors also induced a significant and selective decrease of orexin‐immunoreactive neurons. Moreover, TTX‐induced decrease of orexin immunoreactivity was largely abrogated by concurrent application of a moderate concentration of NMDA. These results suggest that Ca2+ entry associated with nontoxic levels of spontaneous activity of glutamatergic inputs plays an important role in the maintenance of orexin neurons in a tissue culture model. © 2009 Wiley‐Liss, Inc.
Novel highly hydrophilic zwitterionic monolithic column for hydrophilic interaction chromatography
Authors: Jiang Zhengjin , Smith Norman W. , Ferguson Paul D. , Taylor Mark R.
Published: July 2009

A novel zwitterionic hydrophilic porous poly(SPV‐co‐MBA) monolithic column was prepared by thermal co‐polymerisation of 1‐(3‐sulphopropyl)‐4‐vinylpyridinium‐betaine (4‐SPV) and N,N′‐methylenebisacrylamide (MBA). An HILIC/RP dual separation mechanism was observed on this optimised poly(SPV‐co‐MBA) monolithic column and the composition of the mobile phase corresponding to the transition from the HILIC to the RP mode was around 30% ACN in water. Higher hydrophilicity was achieved on this novel monolithic column compared to the poly(N,N‐dimethyl‐N‐methacryloxyethyl‐N‐(3‐sulphopropyl)ammonium betaine‐co‐ethylene dimethacrylate) monolithic column. Permeability studies showed slight swelling and/or shrinking with mobile phases of different polarity. As might be anticipated, a weak electrostatic interaction for charged analytes was also observed by studying the influence of mobile phase pH and salt concentration on their retention on the poly(SPV‐co‐MBA) monolithic column. The final optimised poly(SPV‐co‐MBA) monolith showed comparable selectivities to commercial ZIC‐pHILIC phases for polar test analytes. Fast separation of five pyrimidines and purines was achieved in less than 1 min due to the high permeability of the monolithic column. Additionally, baseline separation of nine benzoic acid derivatives was also observed using either a pH or ACN gradient.
HPLC method for simultaneous determination of retinoids and tocopherols in human serum for monitoring of anticancer therapy
Authors: Krčmová Lenka , Urbánek Lubor , Solichová Dagmar , Kašparová Markéta , Vlčková Hana , Melichar Bohuslav , Sobotka Luboš , Solich Petr
Published: July 2009

A simple and rapid HPLC method requiring small volumes (250 μL) of human serum after C18 SPE sample preparation was developed using monolithic technology for simultaneous determination of all‐trans‐retinoic acid, 13‐cis‐retinoic acid, retinol, gamma‐ and alpha‐tocopherol. The monolithic column, Chromolith Performance RP‐18e (100×4.6 mm), was operated at ambient temperature. The mobile phase consisted of a mixture of acetonitrile (ACN) and 1% ammonium acetate in water (AMC) at pH 7.0. The mobile phase started at 98:2 (v/v) ACN/AMC (column pre‐treatment) at a flow rate of 2 mL/min, then changed to 95:5 (v/v) ACN/AMC for 4 min at a flow rate of 1.5 mL/min and a further 3 min at a flow rate of 3.2 mL/min. Detection and identification were performed using a photodiode array detector. Retinol, 13‐cis‐ and all‐trans‐retinoic acid were monitored at 325 nm. Both alpha‐ and gamma‐tocopherol were detected at 295 nm. The total analysis time was 7.2 min. Tocol (synthesized tocopherol, not occurring in humans) was used as internal standard. The method was linear in the range of 0.125–10.00 μmol/L for all‐trans‐retinoic acid, 0.125–5.00 μmol/L for 13‐cis‐retinoic acid, 0.25–10.00 μmol/L for retinol, 0.5–50.00 μmol/L for gamma‐tocopherol, and 0.5–50.00 μmol/L for alpha‐tocopherol. The present method may be useful for monitoring of retinoids and tocopherols in clinical studies.
Does trauma survey research cause more distress than other types of survey research?
Authors: Ferrier‐Auerbach Amanda G. , Erbes Christopher R. , Polusny Melissa A.
Published: July 2009

Members of institutional review boards who evaluate trauma research protocols frequently face the task of balancing potential risk with potential benefit. However, no known study has examined the relative effect of participating in a trauma‐related survey compared to participating in a nontrauma survey. The authors randomly assigned participants receiving care in an outpatient PTSD treatment program to complete questionnaires assessing either trauma‐related or nontrauma content. Participants completing trauma‐related questionnaires reported feeling sadder and more tense than other participants, though they did not report differences in perceived gain from participation or retrospective willingness to participate. Results suggest that level of distress after participating in trauma research was insufficient to reduce willingness for, or perceived benefit from, participation in trauma survey research.
Binding of Methylene Blue to Polyelectrolytes Containing Sulfonate Groups
Authors: Moreno‐Villoslada Ignacio , Torres Cristian , González Felipe , Shibue Toshimichi , Nishide Hiroyuki
Published: July 2009

The interaction between methylene blue (MB) and poly(sodium 4‐styrenesulfonate) (PSS), poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly[sodium 2‐(N‐acrylamido)‐2‐methyl‐propanesulfonate] (PAMPS), is investigated. The main driving forces for the interaction with PSS are supposed to be short‐range aromatic/aromatic interactions, which explain the smaller dissociation constant, the resistance to the cleaving effect of NaCl, and the prevention of MB self‐aggregation around the macromolecules under a moderate excess of the polymer. On the contrary, as a consequence of long‐range interactions, a higher local concentration of MB around PAMPS and, more significantly, around PVS results in MB self‐aggregation that can be quenched in the presence of NaCl.

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Superhydrophobic Alumina Surfaces Based on Polymer‐Stabilized Oxide Layers
Authors: Höhne Susanne , Blank Christa , Mensch Axel , Thieme Michael , Frenzel Ralf , Worch Hartmut , Müller Martin , Simon Frank
Published: July 2009

Aluminum sheets were furnished with a water‐repellent composite layer consisting of microroughened alumina, chitosan (CHS), and poly[octadecene‐alt‐(maleic anhydride)] (POMA). CHS was electrochemically deposited or spin‐coated. In a subsequent reaction step, POMA was covalently bonded onto the immobilized CHS layer. The produced composite layers showed superhydrophobic properties, which are indicated by the water contact angles >150° and negligible hysteresis. Cross‐linking reactions of the CHS layer were able to enhance the layer stability. The superhydrophobic surface properties were also maintained after abrasion of the protruding polymer‐coated alumina peaks. This is due to a CHS/POMA reservoir incorporated in the microroughened alumina surface region.

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pH Tailoring Electrical and Mechanical Behavior of Polymer–Clay–Nanotube Aerogels
Authors: Gawryla Matthew D. , Liu Lei , Grunlan Jaime C. , Schiraldi David A.
Published: July 2009

Aerogels are low density (<0.1 g · cm−3), highly porous materials that are especially interesting for insulating applications. Combinations of clay and water‐soluble polymers are commonly used to produce aerogels, but these materials are often mechanically weak. Single‐walled carbon nanotubes (SWNT) were combined with clay and found to significantly improve mechanical behavior and impart electrical conductivity to these aerogels. Poly(acrylic acid) (PAA) as the matrix polymer provides a means of tailoring the electrical conductivity and mechanical behavior by altering the pH of the aqueous aerogel precursor suspensions prior to freeze drying. An aerogel, made from a pH 9 aqueous suspension containing 0.5 wt.‐% PAA, 5 wt.‐% clay, and 0.05 wt.‐% SWNT, has a compressive modulus of 373 kPa. In the absence of nanotubes, this modulus is reduced to 43 kPa. Reducing suspension pH to 3, prior to freeze drying, also reduces modulus for these aerogels, but electrical conductivity is increased when nanotubes are present. It was found that bundled nanotubes provide better reinforcement for these low‐density composites, which may provide some new insight into the use of nanotubes in materials that will be exposed to compressive loading.

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Synthesis of Dendritic Oligo‐Spiro(fluorene‐9,9′‐xanthene) Derivatives with Carbazole and Fluorene Pendants and their Thermal, Optical, and Electroluminescent Properties
Authors: Chu Zengze , Wang Dan , Zhang Chao , Fan Xing , Tang Yanwei , Chen Lin , Zou Dechun
Published: July 2009

Two novel spiro‐configured ter(arylene‐ethynylene) derivatives, TSF‐Cz and TSF‐F, have been designed and synthesized using spiro(fluorene‐9,9′‐xanthene) (SFX) as building blocks, introducing a hole‐transporting carbazole and a fluorene chromophore as the peripheral functional group into the backbone through an oxygen atom. The two well‐defined oligomers possess good solubility, film‐forming quality, and high Tg's at 140 and 126 °C, respectively. In addition, these oligomers exhibit blue photoluminescence (PL) emission both in solution and solid states. The double‐layered devices fabricated using the two materials as the emitter show a sky‐blue emission with a brightness and a current efficiency of 7 613 cd · m−2 and 1.11 cd · A−1 for TSF‐Cz, and 1 507 cd · m−2 and 0.36 cd · A−1 for TSF‐F, respectively.

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Macromolecular Recognition of Cyclodextrin: Inversion of Selectivity of β‐Cyclodextrin toward Adamantyl Groups Induced by Macromolecular Chains
Authors: Taura Daisuke , Taniguchi Yosuke , Hashidzume Akihito , Harada Akira
Published: July 2009

Interaction of β‐cyclodextrin (β‐CD) with alternating copolymers (pAdMA and pAdPhMA) of sodium maleate with adamantyl (Ad) and with adamantylphenyl (AdPh) vinyl ether has been investigated by several NMR techniques. Comparing the apparent association constants (K) for the polymers with the K for the model compounds, which are determined by the analysis of 1H NMR and isothermal titration calorimetry data, respectively, the selectivities of β‐CD toward Ad and AdPh moieties are contrasting for the model and polymer systems. This phenomenon is described by circular dichroism and 2D NMR as follows; the most stable inclusion complex for the β‐CD/AdPh model system is extremely destabilized for the corresponding polymer system because of competition with hydrophobic interaction between neighboring AdPh moieties.

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Polymer Fluoride Sensors Synthesized by RAFT Polymerization
Authors: Zhao Ping , Jiang Jianbing , Leng Bing , Tian He
Published: July 2009

A series of polymer chemosensors containing naphthalimide signal moiety and imide recognition moiety for the selective detection of fluoride ions (F−) were synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization. The polymer chemosensors display obvious absorption and fluorescence variations upon the addition of F−, which can be observed by both naked eyes and optical responses. The polymers showed higher fluorescence enhancement than its monomer, and the polymers with higher molecular weight have higher sensitivity than those with lower molecular weight. Other halide anions are found to hardly induce any variation of either the absorption or fluorescence spectra.

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