bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of G‐protein coupled estrogen receptor inhibits the proliferation of cervical cancer cells via sustained activation of ERK1/2
Authors: Zhang Qiong , Wu Yuan‐Zhe , Zhang Yan‐Mei , Ji Xiao‐Hong , Hao Qun
Published: March 2015

Cervical cancer is one of the most common gynaecological women cancer and suggested to be modulated by estrogenic signals. G protein‐coupled receptor (GPER), a seven‐transmembrane G protein‐coupled receptor, has been reported to regulate the cell proliferation of various cancers. But there is no study investigating the effects of GPER on the progression of cervical cancer. In the present study, we revealed for the first time that GPER was also highly expressed in various human cervical cancer cells. Activation of GPER via its specific agonist G‐1 induced G2/M cell cycle arrest and down regulation of cyclin B via a time dependent manner. Furthermore, G‐1 treatment induced sustained activation of extracellular‐signal‐regulated kinases (ERK)1/2 via epidermal growth factor receptor (EGFR) signals. Both inhibitors of ERK1/2 and EGFR significantly abolished G‐1‐induced suppression of cell proliferation and down regulation of cyclin B. Generally, our study revealed that GPER is highly expressed in human cervical cancer cells and its activation inhibits cell proliferation via EGFR/ERK1/2 signals. It suggested that G‐1 can be considered as a potential new pharmacological tool to reduce the growth of cervical cancer. Copyright © 2015 John Wiley & Sons, Ltd.
Promoting Visible‐Light Photocatalysis with Palladium Species as Cocatalyst
Authors: Li Xiuzhen , Zhang Nan , Xu Yi‐Jun
Published: March 2015

Conventionally, Pd catalysis has been widely used in either heterogeneous or homogeneous thermocatalytic organic synthesis. Herein, we demonstrate a case study on the important, cocatalyst role of Pd nanoparticles in ternary In2S3–(reduced graphene oxide–palladium) [In2S3–(RGO–Pd)] composites for the selective oxidation of alcohols under visible‐light irradiation. Pd acts as dual cocatalyst along with RGO to promote the more efficient separation of photogenerated electron–hole pairs and facilitate their spatial transfer across the interface in ternary In2S3–(RGO–Pd) composites, which leads to higher activity than that of binary In2S3–RGO composites. This work highlights the promising scope of using Pd nanoparticles as a cocatalyst for promoting visible‐light photocatalysis towards selective organic transformations under ambient conditions.
Sulfoxide‐Directed Metal‐Free ortho‐Propargylation of Aromatics and Heteroaromatics
Authors: Eberhart Andrew J. , Shrives Harry J. , Álvarez Estela , Carrër Amandine , Zhang Yuntong , Procter David J.
Published: March 2015

A sulfoxide‐directed, metal‐free ortho‐propargylation of aromatics and heteroaromatics exploits intermolecular delivery of a propargyl nucleophile to sulfur followed by an intramolecular relay to carbon. The operationally simple cross‐coupling procedure is general, regiospecific with regard to the propargyl nucleophile, and shows complete selectivity for products of ortho‐propargylation over allenylation. The use of secondary propargyl silanes allows metal‐free ortho‐coupling to form carbon–carbon bonds between aromatic and heteroaromatic rings and secondary propargylic centres. The ‘safety‐catch’ nature of the sulfoxide directing group is illustrated in a selective, iterative double cross‐coupling process. The products of propargylation are versatile intermediates and they have been readily converted into substituted benzothiophenes.
First Evidence for the Existence of Hexafluoroantimonic(V) Acid
Authors: Bour Christophe , Guillot Régis , Gandon Vincent
Published: March 2015

By reacting IPr⋅InBr3 with AgSbF6 in dichloroethane at room temperature, we could obtain single crystals comprising [{(IPr⋅InBr3)(Ag⋅(CH2Cl)2)}2][SbF6]2 (1) and two identical HSbF6 units. It is presumed that the reaction gave rise to [IPr⋅InBr3−x][SbF6]x (x=1, 2, or 3) which reacted with adventitious water to give HSbF6 and [IPr⋅InBr3−x(OH)][SbF6]x−1. The experiment was reproduced at 60 °C, eventually leading to the indium hydroxide [{IPr⋅In(OH)0.5(H2O)4.5}2][SbF6]5 (2).
Pillarene‐Involved Metallic Supramolecular Nanostructures
Authors: Zhang Chang‐Wei , Chen Li‐Jun , Yang Hai‐Bo
Published: March 2015

Pillarenes (or pillararenes), as a new and rapidly developing class of covalent macrocycles, have stimulated a tremendous upsurge of interest in supramolecular chemistry because of their unique features and potentials in fabricating functional materials. In addition, metallo‐supramolecular chemistry has grown steadily over the last few decades. The presence of metal in supramolecular architectures enables the systematic tuning of their properties and endows them with optical, magnetic, and electric etcetera unusual properties. The marriage of these two fields offers new possibilities for the fabrication of novel functional materials and devices. This review article provides an overview of recent advancements on pillararene‐based metallic supramolecular assemblies. The fabrication and functionalities of pillararene‐decorated metallic macrocycles, metal‐organic frameworks (MOFs), and metal nanoparticles are comprehensively summarized and discussed.
Familial clustering of breast and prostate cancer and risk of postmenopausal breast cancer in the Women's Health Initiative Study
Authors: Beebe‐Dimmer Jennifer L. , Yee Cecilia , Cote Michele L. , Petrucelli Nancie , Palmer Nynikka , Bock Cathryn , Lane Dorothy , Agalliu Ilir , Stefanick Marcia L. , Simon Michael S.
Published: March 2015

BACKGROUND

Evidence suggests that the risk of breast and prostate cancer is increased among those with a family history of the same disease and particularly among first‐degree relatives. However, less is known about the relationship between breast and prostate cancer within families and particularly among minority populations.

METHODS

Analyses of participants in the Women's Health Initiative observational cohort who were free of breast cancer at the time of their baseline examination were conducted. Subjects were followed for breast cancer through August 31, 2009. A Cox proportional hazards regression modeling approach was used to estimate the risk of breast cancer associated with a family history of prostate cancer, breast cancer, and both among first‐degree relatives.

RESULTS

There were 78,171 eligible participants, and 3506 breast cancer cases were diagnosed during the study period. A family history of prostate cancer was associated with a modest increase in breast cancer risk after adjustments for confounders (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.02‐1.26). In a separate analysis examining the joint impact of both cancers, a family history of both breast and prostate cancer was associated with a 78% increase in breast cancer risk (aHR, 1.78; 95% CI, 1.45‐2.19). Risk estimates associated with a family history of both breast and prostate cancer were higher among African American women (aHR, 2.34; 95% CI, 1.09‐5.02) versus white women (aHR, 1.66; 95% CI, 1.33‐2.08).

CONCLUSIONS

These findings suggest that prostate cancer diagnosed among first‐degree family members increases a woman's risk of developing breast cancer. Future studies are needed to determine the relative contributions of genes and a shared environment to the risk for both cancers. Cancer 2015;121:1265–1272. © 2014 American Cancer Society.
Stochastic Stability of Lyapunov Exponents and Oseledets Splittings for Semi‐invertible Matrix Cocycles
Authors: Froyland Gary , González‐Tokman Cecilia , Quas Anthony
Published: March 2015

We establish (i) stability of Lyapunov exponents and (ii) convergence in probability of Oseledets spaces for semi‐invertible matrix cocycles subjected to small random perturbations. The first part extends results of Ledrappier and Young to the semi‐invertible setting. The second part relies on the study of evolution of subspaces in the Grassmannian; the analysis developed here is based on higher‐dimensional Möbius transformations and is likely to be of wider interest. © 2015 Wiley Periodicals, Inc.
Distributed space‐time block codes with embedded adaptive AAF/DAF elements and opportunistic listening for multihop power line communication networks
Authors: Tseng Shu‐Ming , Lee Te‐Lun , Ho Yo‐Chain , Tseng Der‐Feng
Published: March 2015

We consider the multihop power line communication (PLC) networks of one source, two repeaters, and one destination. In the previous scheme, when the repeaters receive the retransmission data from the source, they use the traditional distributed space‐time block code (DSTBC) with all decode‐and‐forward (DAF) elements to transmit the data, and they do not consider the incorrect decoding. The original contribution is that we propose a novel DSTBC scheme with embedded adaptive DAF/amplify‐and‐forward (AAF) elements for data retransmission in multihop PLC networks with existing opportunistic listening (OL) protocols. The new scheme has two types (instead of only one type as in the previous scheme), and, in the second type, the coding matrix for data retransmission can use either all DAF elements or hybrid AAF/DAF elements depending on the correctness of OL results. The advantage is to avoid a loss of diversity because of incorrectly received data at the relays. The effectiveness of the proposed scheme is shown in the simulation results. For the impulsive noise parameter δ = 0.8 and worst case background noise (narrowband interference and colored noise) at bit error rate 10−3, our proposed system has 1 dB gain over the previous scheme with the traditional DSTBC with all DAF elements. Copyright © 2015 John Wiley & Sons, Ltd.
Spatially variable habitat quality contributes to within‐population variation in reproductive success
Authors: Griffen Blaine D. , Norelli Alexandra P.
Published: March 2015

Variation in habitat quality is common across terrestrial, freshwater, and marine habitats. We investigated how habitat quality influenced the reproductive potential of mud crabs across 30 oyster reefs that were degraded to different extents. We further coupled this field survey with a laboratory experiment designed to mechanistically determine the relationship between resource consumption and reproductive performance. We show a >10‐fold difference in average reproductive potential for crabs across reefs of different quality. Calculated consumption rates for crabs in each reef, based on a type II functional response, suggest that differences in reproductive performance may be attributed to resource limitation in poor quality reefs. This conclusion is supported by results of our laboratory experiment where crabs fed a higher quality diet of abundant animal tissue had greater reproductive performance. Our results demonstrate that spatial variation in habitat quality can be a considerable contributor to within‐population individual variation in reproductive success (i.e., demographic heterogeneity). This finding has important implications for assessing population extinction risk.
Altered dynamics of broad‐leaved tree species in a Chinese subtropical montane mixed forest: the role of an anomalous extreme 2008 ice storm episode
Authors: Ge Jielin , Xiong Gaoming , Wang Zhixian , Zhang Mi , Zhao Changming , Shen Guozhen , Xu Wenting , Xie Zongqiang
Published: March 2015

Extreme climatic events can trigger gradual or abrupt shifts in forest ecosystems via the reduction or elimination of foundation species. However, the impacts of these events on foundation species' demography and forest dynamics remain poorly understood. Here we quantified dynamics for both evergreen and deciduous broad‐leaved species groups, utilizing a monitoring permanent plot in a subtropical montane mixed forest in central China from 2001 to 2010 with particular relevance to the anomalous 2008 ice storm episode. We found that both species groups showed limited floristic alterations over the study period. For each species group, size distribution of dead individuals approximated a roughly irregular and flat shape prior to the ice storm and resembled an inverse J‐shaped distribution after the ice storm. Furthermore, patterns of mortality and recruitment displayed disequilibrium behaviors with mortality exceeding recruitment for both species groups following the ice storm. Deciduous broad‐leaved species group accelerated overall diameter growth, but the ice storm reduced evergreen small‐sized diameter growth. We concluded that evergreen broad‐leaved species were more susceptible to ice storms than deciduous broad‐leaved species, and ice storm events, which may become more frequent with climate change, might potentially threaten the perpetuity of evergreen‐dominated broad‐leaved forests in this subtropical region in the long term. These results underscore the importance of long‐term monitoring that is indispensible to elucidate causal links between forest dynamics and climatic perturbations.
Seed weight and germination behavior of the submerged plant Potamogeton pectinatus in the arid zone of northwest China
Authors: Li Zhongqiang , Lu Wei , Yang Lei , Kong Xianghong , Deng Xuwei
Published: March 2015

Variation in seed weight is common within and among plant species, but few studies have attempted to document the pattern of seed weight and germination attributes for aquatic macrophytes at a large scale. This study examined within‐species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant Potamogeton pectinatus in the arid zone of northwest China. Our results showed that the average seed weight was 0.24 g per 100 seeds with a coefficient of variation (CV) of 28.4% among the eight P. pectinatus populations. The total germination fraction of seeds of P. pectinatus was relatively poor, less than 35% in seven P. pectinatus populations, and the lowest germination percentage found was only 2%. There were significant differences in seed weight, time to onset of germination, and total germination fraction among the eight different populations. Hierarchical partitioning analysis showed a strongly positive correlation between seed weight and water temperature and pH. Seed weight and the maternal environmental factors significantly affected both time to initiation of germination and total germination fraction. Our results suggest that (1) seed weight variation in P. pectinatus primarily is the result of temperature variation during fruit development; (2) relatively poor germination fraction suggests that seeds are relatively unimportant in the short‐term survival of populations and that it may be another adaptive trait allowing plants to take place in the right place and at the right time, especially in harsh environment; and (3) variation in seed germination traits should be determined by local environmental and intrinsic factors that interact in a complex fashion.
Treg‐cell depletion promotes chemokine production and accumulation of CXCR3+ conventional T cells in intestinal tumors
Authors: Akeus Paulina , Langenes Veronica , Kristensen Jonas , von Mentzer Astrid , Sparwasser Tim , Raghavan Sukanya , Quiding‐Järbrink Marianne
Published: March 2015

Colorectal cancer (CRC) is one of the most prevalent tumor types worldwide and tumor‐infiltrating T cells are crucial for anti‐tumor immunity. We previously demonstrated that Treg cells from CRC patients inhibit transendothelial migration of conventional T cells. However, it remains unclear if local Treg cells affect lymphocyte migration into colonic tumors. By breeding APCMin/+ mice with depletion of regulatory T cells mice, expressing the diphtheria toxin receptor under the control of the FoxP3 promoter, we were able to selectively deplete Treg cells in tumor‐bearing mice, and investigate the impact of these cells on the infiltration of conventional T cells into intestinal tumors. Short‐term Treg‐cell depletion led to a substantial increase in the frequencies of T cells in the tumors, attributed by both increased infiltration and proliferation of T cells in the Treg‐cell‐depleted tumors. We also demonstrate a selective increase of the chemokines CXCL9 and CXCL10 in Treg‐cell‐depleted tumors, which were accompanied by accumulation of CXCR3+ T cells, and increased IFN‐γ mRNA expression. In conclusion, Treg‐cell depletion increases the accumulation of conventional T cells in intestinal tumors, and targeting Treg cells could be a possible anti‐tumor immunotherapy, which not only affects T‐cell effector functions, but also their recruitment to tumors.
Facile Synthesis of ZnO–Reduced Graphene Oxide Nanocomposites for NO2 Gas Sensing Applications
Authors: Kumar Nagesh , Srivastava Arvind Kumar , Patel Hari Shankar , Gupta Bipin Kumar , Varma Ghanshyam Das
Published: March 2015

Graphene and its exotic forms have been widely recognized as exceptional materials for gas‐sensing applications because of their extraordinary electrical conductivity and large surface area to volume ratios. Herein, chemically reduced graphene oxide (rGO) and zinc oxide–reduced graphene oxide (ZrGO) nanocomposite powders have been successfully synthesized through a simple hydrolysis method followed by annealing in ambient N2 gas. The reduction of graphene oxide by hydrazine hydrate and the decoration of the graphene surface by ZnO nanoparticles have occurred during the synthesis process. The prepared samples were characterized by various microscopic techniques to explore the surface morphology and uniformity. Spectroscopic techniques were used to investigate the quality of the as‐synthesized powder samples as well as the extent of graphitization of the samples. Coil sensors with two Pt terminals and a heating element have been designed to extensively monitor the effect of temperature on the electrical and gas‐sensing properties of the rGO and ZrGO nanocomposite samples. The ZrGO nanocomposites possess better electrical and NO2 gas sensing properties than the pristine rGO. The ZrGO nanocomposite sensor exhibits a high response (ca. 32 %) for 50 ppm NO2 at relatively low temperature (50 °C). Our results suggest that the ZrGO nanocomposite material could be used to fabricate a new generation of low‐power portable NO2 sensors.
Structural Influencing Factors on ZnII/CdII Coordination Polymers Based on Tri‐pyridyl‐bis‐amide: Assembly, Structures, Fluorescent Sensing and Selective Photocatalysis
Authors: Wang Xiu‐Li , Chen Nai‐Li , Liu Guo‐Cheng , Lin Hong‐Yan , Zhang Ju‐Wen
Published: March 2015

Fourteen new ZnII/CdII coordination polymers tuned by semi‐rigid “V”‐like tri‐pyridyl‐bis‐amide ligands with different spacers and different dicarboxylates co‐ligands, namely, {[Zn(L1)(mip)]·H2O}n (1), {[Zn2(L1)2(hip)2]·H2O}n (2), {[Zn(L1)(oba)]·H2O}n (3), {[Zn(L1)(chda)]·H2O}n (4), {[Cd2(L1)(mip)2(H2O)]·2H2O}n (5), {[Cd(L1)(hip)]·4H2O}n (6), {[Cd(L1)(oba)]·H2O}n (7), {[Cd3(L1)(chda)3]·4H2O}n (8), [Zn(L2)(mip)]n (1a), {[Zn(L2)(hip)(H2O)]·3H2O}n (2a), [Zn(L2)(oba)]n (3a), {[Cd(L2)(hip)]·3H2O}n (6a), {[Cd(L2)(oba)]·H2O}n (7a), [Cd(L2)(chda)]n (8a), [L1 = N,N′‐di(pyridin‐3‐yl)pyridine‐2,6‐dicarboxamide, L2 = N,N′‐di(pyridin‐3‐yl)pyridine‐3,5‐dicarboxamide, H2mip = 5‐methylisophthalic acid, H2hip = 5‐hydroxyisophthalic acid, H2oba = 4,4′‐oxybis(benzoic acid), H2chda = trans‐1,4‐cyclohexanedicarboxylic acid] have been hydrothermally synthesized and structurally characterized. Complexes 1–4 based on the same L1 ligand and ZnII ion show various structures. Complex 1 features a two‐dimensional (2D) network, which consists of a linear [Zn‐mip]n chain and [Zn‐L1]n left‐, right‐handed helixes. Complex 2 is a twofold interpenetrating 2D→2D network. In complex 3, Zn2(L1)2 loops were connected by oba anions creating a 1D channel‐like structure. Complex 4 is a 2D layer containing [Zn‐chda]n right‐handed helixs and Zn2(L1)2 loops. Complexes 5–8 with CdII ion exhibit different structures. Complex 5 features a 1D belt structure based on Cd4(COO)4 subunits. However, complex 6 exhibits a 2D network constructed from [Cd‐hip]n ladder‐like chains and Cd2(L1)2 loops. Complex 7 shows a 1D double chain structure containing [Cd‐oba]n zigzag chain and [Cd‐L1]n meso‐right‐handed helix. Complex 8 exhibits a 2D network based on 2D [Cd‐chda] layer and 1D [Cd‐L1]n meso‐helical chain. For complexes 1a–8a based on L2 ligand, complex 1a is a 2D layer containing [Zn‐mip]n linear chain and [Zn‐L2]n meso‐helical chain. The structure of complex 2a is very similar to that of 3. Complex 3a exhibits a 2D grid network containing 1D [Zn‐oba]n and [Zn‐L2]n chains. Complex 6a shows a 2D layer based on [Cd2(hip)2]n double chain and [Cd‐L2]n chain. The structure of complex 7a is very similar to that of 7. Complex 8a is a 3,5‐connected 3D framework with the Schläfli symbol of (42.65.83)(42.6), which is constructed from [Cd‐L2]n channel‐like chains and chda linkers. The structural diversity of the title complexes indicates that the tri‐pyridyl‐bis‐amide ligands with different spacers, the dicarboxylates and central metals play important roles in tuning the dimensionalities and structures of the target complexes. The title complexes exhibit excellent photocatalytic activity and selectivity for organic dyes degradation under UV light. In addition, fluorescent sensing behaviors of 3, 6, 7 and 7a toward different organic solvents have been investigated in detail.
Exfoliation of Bulk Inorganic Layered Materials into Nanosheets by the Rapid Quenching Method and Their Electrochemical Performance
Authors: Chakravarty Disha , Late Dattatray J.
Published: March 2015

We report herein the results of our investigations on the synthesis of transition‐metal dichalcogenide (TMDC) semiconductor layered materials of MoS2, WS2, MoSe2, and WSe2 by the rapid quenching method. The bulk powders were added to deionized water in a polypropylene tube and subsequently flushed with argon gas. Thirty rapid freezing (30 s in a liquid nitrogen bath) and heating (20 min in an oil bath at 60 °C) cycles were then carried out. The reaction product was obtained in a yield in excess of 60 wt.‐%, which indicates that the method can be utilized on an industrial scale for the production of 2D nanosheets. The as‐synthesized products were then characterized by TEM, which revealed nanosheet‐like morphologies. Raman spectroscopy confirmed the high quality of the nanosheet samples. The exfoliated samples also showed good electrochemical performance. Of the TMDC samples investigated, the WSe2 nanosheets were found to give the best performance due to their uniform morphology, large surface area, and fewest number of defects.
Solvent‐Dependent Iodoargentate Hybrids: Syntheses, Structural Diversity, Thermochromism, and Photocatalysis
Authors: Yu Tanlai , Shen Junju , Wang Yilin , Fu Yunlong
Published: March 2015

Charge‐balanced by protonated pyridine, four iodoargentate hybrids, [(Hpy)(Ag2I3)]n (1, 2D), {[(Hpy)2·dmf][Ag6I8]}n (2, 2D), {[(Hpy)2·H2O][Ag3I5]}n (3, 1D) and [(Hpy)(Ag5I6)]n (4, reported 3D) (Hpy+ = protonated pyridine, dmf = N,N‐dimethylformamide), were synthesized in the system comprising pyridine/AgI/HI/solvent (solvent: acetone for 1, DMF for 2, acetone/H2O for 3, and acetonitrile for 4). Structural analysis revealed the significant influence of the solvent on the assembly and crystallization of the iodoargentate hybrids. Noteworthy, compounds 2–4 reveal a good structural match between the structure‐directing agents and the inorganic frameworks. The band gaps of 1–4 (2.93, 3.05, 2.99, and 2.71 eV for 1, 2, 3, and 4, respectively) also exhibit an intense correlation between the structural features of the hybrids and their photocatalytic properties in the degradation of rhodamine B under UV‐light irradiation. Moreover, compound 4 shows interesting thermochromism owing to its temperature‐dependent intermolecular charge transfer.
A Chemoselective and Modular Post‐Synthetic Multi‐Functionalization of NHC–Platinum Complexes
Authors: Dahm Georges , Borré Etienne , Guichard Gilles , Bellemin‐Laponnaz Stéphane
Published: March 2015

We report oxime ligation in combination with metal ligand exchange as a novel orthogonal and practical approach to the multifunctionalization of NHC–platinum complexes. This strategy, which enables strong diversity enhancement of metallodrug candidates, could also be applied to selective bioconjugation.
Pyrimidine‐Derived Prolinamides as Recoverable Bifunctional Organocatalysts for Enantioselective Inter‐ and Intramolecular Aldol Reactions under Solvent‐Free Conditions
Authors: Vizcaíno‐Milla Pascuala , Sansano José M. , Nájera Carmen , Fiser Béla , Gómez‐Bengoa Enrique
Published: March 2015

Chiral L‐prolinamides 2 containing the (R,R)‐ and (S,S)‐trans‐cyclohexane‐1,2‐diamine scaffold and a 2‐pyrimidinyl unit are synthesized and used as general organocatalysts for intermolecular and intramolecular aldol reactions with 1,6‐hexanedioic acid as a co‐catalyst under solvent‐free conditions. The intermolecular reaction between ketone–aldehyde and aldehyde–aldehyde must be performed under wet conditions with catalyst (S,S)‐2b at 10 °C, which affords anti‐aldols with high regio‐, diastereo‐, and enantioselectivities. For the Hajos–Parrish–Eder–Sauer–Wiechert reaction, both diastereomers of catalyst 2 give similar results at room temperature in the absence of water to give the corresponding Wieland–Miescher ketone and derivatives. Both types of reactions were scaled up to 1 g, and the organocatalysts were recovered by extractive workup and reused without any appreciable loss in activity. DFT calculations support the stereochemical results of the intermolecular process and the bifunctional role played by the organocatalyst by providing a computational comparison of the H‐bonding networks occurring with catalysts 2a and 2b.
Capillary zone electrophoresis method for the direct determination of amino acids in recombinant human erythropoietin preparations used for the treatment of anemia
Authors: de Souza Crespo Izabel Cristina , de Resende Matheus Troina , Pereira Netto Annibal Duarte , de Carvalho Marques Flávia Ferreira
Published: March 2015

A method based on CZE for the determination of glutamic acid, glycine, and alanine in a biopharmaceutical formulation containing recombinant human erythropoietin was developed. The separation was achieved within less than 5 min, using a fused‐silica capillary column (55 cm × 50 μm id) and 30 mmol/L phosphate buffer at pH 11.5, containing 0.6 mmol/L CTAB and 10% v/v methanol, as BGE solution. Applied potential of –25 kV, temperature of 15°C and hydrodynamic injection time of 15 s, at 50 mbar, were employed. The detection of the analytes was carried out without any derivatization reaction, at 220 nm using an UV‐DAD detector. Linear ranges from 50 to 2500 mg/L and quantification limits of 40, 39, and 37 mg/L were obtained for glutamic acid, glycine, and alanine, respectively. Sample preparation required only a dilution step. Considering peak area and migration time values, the method presented good repeatability (RSD <1.7%; n = 9) and intermediate precision (RSD <1.0%; n = 6). Recovery evaluation using a commercial sample led to values between 97.5 ± 5.2% and 101.5 ± 4.6%, demonstrating the feasibility of the method, which was successfully applied in the quantification of the amino acids of interest in biopharmaceutical samples.
Low aspect ratio micropores for single‐particle and single‐cell analysis
Authors: Goyal Gaurav , Mulero Rafael , Ali Jamel , Darvish Armin , Kim Min Jun
Published: March 2015

This paper describes microparticle and bacterial translocation studies using low aspect ratio solid‐state micropores. Micropores, 5 μm in diameter, were fabricated in 200 nm thick free‐standing silicon nitride membranes, resulting in pores with an extremely low aspect ratio, nominally 0.04. For microparticle translocation experiments, sulfonated polystyrene microparticles and magnetic microbeads in size range of 1–4 μm were used. Using the microparticle translocation characteristics, we find that particle translocations result in a change only in the pore's geometrical resistance while the access resistance remains constant. Furthermore, we demonstrate the ability of our micropore to probe high‐resolution shape information of translocating analytes using concatenated magnetic microspheres. Distinct current drop peaks were observed for each microsphere of the multibead architecture. For bacterial translocation experiments, nonflagellated Escherichia coli (strain HCB 5) and wild type flagellated Salmonella typhimurium (strain SJW1103) were used. Distinct current signatures for the two bacteria were obtained and this difference in translocation behavior was attributed to different surface protein distributions on the bacteria. Our findings may help in developing low aspect ratio pores for high‐resolution microparticle characterization and single‐cell analysis.
In‐source fragmentation and correlation analysis as tools for metabolite identification exemplified with CE‐TOF untargeted metabolomics
Authors: Godzien Joanna , Armitage Emily G. , Angulo Santiago , Martinez‐Alcazar Mari Paz , Alonso‐Herranz Vanesa , Otero Abraham , Lopez‐Gonzalvez Angeles , Barbas Coral
Published: March 2015

The role of non‐targeted metabolomics with its discovery power is constantly growing in many different fields of science. However, its biggest advantage of uncovering the unexpected is turning into one of its biggest bottlenecks, particularly in metabolite identification. Among different methods for metabolite identification or ID confirmation, tandem MS analysis plays a very important role. However, this method is limited to only certain types of MS analysers, making for example TOF‐MS inaccessible for this type of metabolite identification. To overcome this, in‐source fragmentation has been used to fragment molecules and obtain product ions. Since the molecule of interest is not isolated prior to its fragmentation, the acquired spectrum contains many different signals arising from the fragmentation of all compounds present in the sample. Therefore, to assign product ions to their precursors, a novel use of correlation analysis was tested with r ≥0.9 as an assignation of a product ion belonging to the precursor. This method and chosen cut‐off was tested on three different sample complexity levels: conducting the analysis on a single standard, mix of co‐eluting standards and on a plasma sample. Obtained results clearly proved the effectiveness of the proposed methodology for metabolite ID confirmation. Moreover, the proposed strategy can be successfully applied for semi‐quantification of co‐eluting molecules with the same monoisotopic mass but that differ in fragmentation pattern. The proposed methodology can greatly improve the robustness and throughput of identification in metabolomics studies by use of TOF‐MS, which is crucial to obtain meaningful and trustful results.
Antioxidative responses during germination in quinoa grown in vitamin B‐rich medium
Authors: Pitzschke Andrea , Fraundorfer Anna , Guggemos Michael , Fuchs Norbert
Published: March 2015

Synthetic vitamin preparations have grown in popularity to combat health risks associated with an imbalanced diet, poor exercise and stress. In terms of bioavailability and diversity, they lack behind vitamins naturally occurring in plants. Solutions to obtain plant‐derived vitamins at a larger scale are highly desirable. B vitamins act as precursors of enzymatic cofactors, thereby regulating important metabolic processes both in animals and plants. Because during plant germination, the vitamin content and micronutrient availability increase, sprouts are generally considered a healthier food as compared to dry grains. Germination only occurs if a plant′s antioxidant machinery is sufficiently activated to cope with oxidative stress. Seeds of quinoa, an edible gluten‐free plant naturally rich in minerals, germinate readily in a solution containing the eight B vitamins. We studied biochemical changes during quinoa germination, with a focus on nutritionally relevant characteristics. The results are considered from a nutritional and plant physiological perspective. Germination of quinoa in vitamin‐rich medium is a promising strategy to enhance the nutritional value of this matrix. Additional health‐beneficial effects indirectly resulting from the vitamin treatment include elevated levels of the multi‐functional amino acid proline and a higher antioxidant capacity. Plant biomolecules can be better protected from oxidative damage in vivo.
Nutrients and bioactive compounds content of Baillonella toxisperma, Trichoscypha abut and Pentaclethra macrophylla from Cameroon
Authors: Fungo Robert , Muyonga John , Kaaya Archileo , Okia Clement , Tieguhong Juius C. , Baidu‐Forson Jojo J.
Published: March 2015

Baillonella toxisperma, Pentaclethra macrophylla and Trichoscypha abut are important foods for communities living around forests in Cameroon. Information on the nutritional value and bioactive content of these foods is required to establish their contribution to the nutrition and health of the communities. Samples of the three foods were obtained from four villages in east and three villages in south Cameroon. The foods were analyzed for proximate composition, minerals and bioactive content using standard chemical analysis methods. T. abut was found to be an excellent source of bioactive compounds; flavonoids (306 mg/100 g), polyphenols (947 mg/100 g), proanthocyanins (61.2 mg/100 g), vitamin C (80.05 mg/100 g), and total oxalates (0.6 mg/100 g). P. macrophylla was found to be a rich source of total fat (38.71%), protein (15.82%) and total fiber (17.10%) and some bioactive compounds; vitamin E (19.4 mg/100 g) and proanthocyanins (65.0 mg/100 g). B. toxisperma, was found to have high content of carbohydrates (89.6%), potassium (27.5 mg/100 g) and calcium (37.5 mg/100 g). Flavonoids, polyphenols, vitamins C and E are the main bioactive compounds in these forest foods. The daily consumption of some of these fruits may coffer protection against some ailments and oxidative stress. Approximately 200 g of either B. toxisperma or P. macrophylla, can supply 100% iron and zinc RDAs for children aged 1–3 years, while 300 g of the two forest foods can supply about 85% iron and zinc RDAs for non‐pregnant non‐lactating women. The three foods provide 100% daily vitamins C and E requirements for both adults and children. The results of this study show that Baillonella toxisperma, Pentaclethra macrophylla and Trichoscypha abut can considerably contribute towards the human nutrient requirements. These forest foods also contain substantial levels of health promoting phytochemicals notably flavonoids, polyphenols, vitamins C and E. These foods therefore have potential to promote nutrition and health, especially among forest dependent communities who consume them in substantial amounts.
Detection rate of 99mTc‐MIBI single photon emission computed tomography (SPECT)/CT in preoperative planning for patients with primary hyperparathyroidism: A meta‐analysis
Authors: Treglia Giorgio , Sadeghi Ramin , Schalin–Jäntti Camilla , Caldarella Carmelo , Ceriani Luca , Giovanella Luca , Eisele David W.
Published: March 2015

abstract

Background

Parathyroid scintigraphy using 99mTc‐MIBI single photon emission computed tomography (SPECT)/CT has been proposed as one of the most accurate localization techniques in patients with primary hyperparathyroidism (PHPT). The purpose of this review was to meta‐analyze published data on the detection rate of 99mTc‐MIBI SPECT/CT in the preoperative planning of patients with PHPT.

Methods

A comprehensive literature search of studies published through June 2014 was performed. The pooled detection rate of this scintigraphic method including 95% confidence intervals (95% CIs) was calculated on a per patient‐based and on a per lesion‐based analysis by using a random effects model.

Results

Twenty‐three articles including 1236 patients with PHPT were selected. The pooled detection rate of 99mTc‐MIBI SPECT/CT in the preoperative planning of patients with PHPT was 88% (95% CI = 84% to 92%) and 88% (95% CI = 82% to 92%) on a per patient‐based and per lesion‐based analysis, respectively.

Conclusion

The 99mTc‐MIBI SPECT/CT has high detection rate for hyperfunctioning parathyroid glands in patients with PHPT. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2159–E2172, 2016
Reduction in cervical intraepithelial neoplasia in young women inBritishColumbia after introduction of theHPVvaccine: An ecological analysis
Authors: Ogilvie Gina S. , Naus Monika , Money Deborah M. , Dobson Simon R. , Miller Dianne , Krajden Mel , van Niekerk Dirk J. , Coldman Andrew J.
Published: March 2015

We report on the rates of cervical intraepithelial neoplasia (CIN) in young women aged 15–22 years of age in British Columbia before and after the introduction of an HPV vaccine program. Rates of cervical intraepithelial neoplasia (CIN) 2+ for each age stratum (15–22) in the calendar years 2004–2012 for the province of British Columbia were obtained from the BC Cancer Agency‘s population‐based cervical cancer program. Incidence rate ratios (IRR) of CIN2+ were described and compared before and after HPV vaccine program introduction in cohorts born in vaccine eligible years, and in non‐vaccine eligible years using piece‐wise Poisson regression analysis, and adjusted for age. Between 2004 and 2012, rates of CIN2 and CIN2+ in young women aged 15–22 years in the province of British Columbia have decreased overall. After the introduction of the HPV vaccine program, the age adjusted IRR for CIN2+ for young women aged 15–17 years decreased significantly from 0.91 (95% CI: 0.86–0.98p < 0.01) to 0.36 (95% CI: 0.18–0.73p < 0.01). During the same time period, no similar reduction was found in young women 18–22 years. After introduction of HPV vaccine program, IRR for CIN2+ in young women 15–17 was significantly reduced for CIN2+ (0.14; 95% CI: 0.04– 0.47;p < 0.01) and CIN2 (0.1; 95% CI: 0.02–0.54;p < 0.01). This ecological analysis shows a significant reduction in CIN2+ lesions in young women aged 15–17 years in British Columbia after the introduction of the HPV vaccine in young women despite vaccine uptake levels below 70%.
Biological relevance of Hsp90‐binding immunophilins in cancer development and treatment
Authors: Mazaira Gisela I. , Camisay María F. , De Leo Sonia , Erlejman Alejandra G. , Galigniana Mario D.
Published: March 2015

Immunophilins are a family of intracellular receptors for immunosuppressive drugs. Those immunophilins that are related to immunosuppression are the smallest proteins of the family, i.e., FKBP12 and CyPA, whereas the other members of the family have higher molecular weight because the show additional domains to the drug‐binding site. Among these extra domains, the TPR‐domain is perhaps the most relevant because it permits the interaction of high molecular weight immunophilins with the 90‐kDa heat‐shock protein, Hsp90. This essential molecular chaperone regulates the biological function of several protein‐kinases, oncogenes, protein phosphatases, transcription factors and cofactors . Hsp90‐binding immunophilins where first characterized due to their association with steroid receptors. They regulate the cytoplasmic transport and the subcellular localization of these and other Hsp90 client proteins, as well as transcriptional activity, cell proliferation, cell differentiation and apoptosis. Hsp90‐binding immunophilins are frequently overexpressed in several types of cancers and play a key role in cell survival. In this article we analyze the most important biological actions of the best characterized Hsp90‐binding immunophilins in both steroid receptor function and cancer development and discuss the potential use of these immunophilins for therapeutic purposes as potential targets of specific small molecules.
Progesterone Inhibits Endothelial Cell Migration Through Suppression of the Rho Activity Mediated by cSrc Activation
Authors: Lee Tong‐Sheng , Lin Jhen‐Jhe , Huo Yen‐Nien , Lee Wen‐Sen
Published: March 2015

We previously showed that progesterone (P4) could inhibit the proliferation of human umbilical venous endothelial cells (HUVECs) through the p53‐dependent pathway. In the present study, we further demonstrated that P4 at physiologic levels (5–500 nM) concentration‐dependently inhibited migration of HUVECs. This effect was blocked by pre‐treatment with the P4 receptor (PR) agonist‐antagonist, RU486, suggesting that the P4‐induced migration inhibition in HUVECs was through the PR‐mediated signaling pathway. Western blot analyses demonstrated that the levels of RhoA and Rac‐1 protein were reduced in the P4‐treated HUVECs. P4 also inhibited the membrane translocation of RhoA and Rac‐1 protein. Moreover, the P4‐induced migration inhibition in HUVECs was prevented by over‐expression of the constitutively active RhoA construct (RhoA V14). However, pre‐treatment with the ROCK (a kinase associated with RhoA for transducing RhoA signaling) inhibitor, Y27632, abolished the over‐expression of RhoA‐induced prevention effect on the P4‐induced migration inhibition in HUVECs. These data suggest that the inhibition of Rho GTPases might account for the P4‐induced migration inhibition of HUVECs. Pre‐treatment with the cSrc inhibitor, PP2, prevented the P4‐induced migration inhibition in HUVEC. The levels of phosphorylated focal adhesion kinase (FAK) and paxillin protein were also decreased by P4 treatment. Taken together, these results suggest that suppression of the Rho‐mediated pathway might be involved in the signal transduction leading to the inhibition of cell migration caused by P4 in HUVECs. J. Cell. Biochem. 116: 1411–1418, 2015. © 2015 Wiley Periodicals, Inc.
On combining Thole's induced point dipole model with fixed charge distributions in molecular mechanics force fields
Authors: Antila Hanne S. , Salonen Emppu
Published: March 2015

The Thole induced point dipole model is combined with three different point charge fitting methods, Merz–Kollman (MK), charges from electrostatic potentials using a grid (CHELPG), and restrained electrostatic potential (RESP), and two multipole algorithms, distributed multipole analysis (DMA) and Gaussian multipole model (GMM), which can be used to describe the electrostatic potential (ESP) around molecules in molecular mechanics force fields. This is done to study how the different methods perform when intramolecular polarizability contributions are self‐consistently removed from the fitting done in the force field parametrization. It is demonstrated that the polarizable versions of the partial charge models provide a good compromise between accuracy and computational efficiency in describing the ESP of small organic molecules undergoing conformational changes. For the point charge models, the inclusion of polarizability reduced the the average root mean square error of ESP over the test set by 4–10%. © 2015 Wiley Periodicals, Inc.
Inhibition of PKC‐Induced COX‐2 and IL‐8 Expression in Human Breast Cancer Cells by Glucosamine
Authors: Chou Wan‐Yu , Chuang Kun‐Han , Sun David , Lee Yu‐Hsiu , Kao Pu‐Hong , Lin Yen‐Yu , Wang Hsei‐Wei , Wu Yuh‐Lin
Published: March 2015

Breast cancer is a common cancer leading to many deaths among females. Cyclooxygenase‐2 (COX‐2) and interleukin‐8 (IL‐8) are two highly expressed inflammatory mediators to be induced by the protein kinase C (PKC) signaling via various inflammatory stimuli and both contribute significantly to cancer metastasis/progression. Glucosamine has been shown to act as an anti‐inflammation molecule. The aim of this study was to clarify the role and acting mechanism of glucosamine during the PKC‐regulation of COX‐2/IL‐8 expression and the associated impact on breast cancer. In MCF‐7 breast cancer cells, glucosamine effectively suppresses the PKC induction of COX‐2 and IL‐8 promoter activity, mRNA and protein levels, as well as the production of prostaglandin E2 (PGE2) and IL‐8. Glucosamine is able to promote COX‐2 protein degradation in a calpain‐dependent manner and IL‐8 protein degradation in calpain‐dependent and proteasome‐dependent manners. The MAPK and NF‐κB pathways are involved in PKC‐induced COX‐2 expression, but only the NF‐κB pathway is involved in PKC‐induced IL‐8 expression. Glucosamine attenuates PKC‐mediated IκBα phosphorylation, nuclear NF‐κB translocation, and NF‐κB reporter activation. Both PGE2 and IL‐8 promote cell proliferation and IL‐8 induces cell migration; thus, glucosamine appears to suppress PKC‐induced cell proliferation and migration. Furthermore, glucosamine significantly inhibits the growth of breast cancer xenografts and this is accompanied by a reduction in COX‐2 and IL‐8 expression. In conclusion, glucosamine seems to attenuate the inflammatory response in vitro and in vivo and this occurs, at least in part by targeting to the NF‐κB signaling pathway, resulting in an inhibition of breast cancer cell growth. J. Cell. Physiol. 230: 2240–2251, 2015. © 2015 Wiley Periodicals, Inc.
Gap Junctions Enhance the Antiproliferative Effect of MicroRNA‐124‐3p in Glioblastoma Cells
Authors: Suzhi Zhang , Liang Tao , Yuexia Peng , Lucy Liu , Xiaoting Hong , Yuan Zhang , Qin Wang
Published: March 2015

MicroRNA (miRNA) holds promise as a novel therapeutic tool for cancer treatment. However, the transfection efficiency of current delivery systems represents a bottleneck for clinical applications. Here, we demonstrate that gap junctions mediate an augmentative effect on the antiproliferation mediated by miR‐124‐3p in U87 and C6 glioblastoma cells. The functional inhibition of gap junctions using either siRNA or pharmacological inhibition eliminated the miR‐124‐3p‐mediated antiproliferation, whereas the enhancement of gap junctions with retinoic acid treatment augmented this miR‐124‐3p‐mediated antiproliferation. A similar effect was observed in glioblastoma xenograft models. More importantly, patch clamp and co‐culture assays demonstrated the transmission of miR‐124‐3p through gap junction channels into adjacent cells. In further exploring the impact of gap junction‐mediated transport of miR‐124‐3p on miR‐124‐3p target pathways, we found that miR‐124‐3p inhibited glioblastoma cell growth in part by decreasing the protein expression of cyclin‐dependent kinase 6, leading to cell cycle arrest at the G0/G1 phase; moreover, pharmacological regulation of gap junctions affected this cell cycle arrest. In conclusion, our results indicate that the “bystander” effects of functional gap junctions composed of connexin 43 enhance the antitumor effect of miR‐124‐3p in glioblastoma cells by transferring miR‐124‐3p to adjacent cells, thereby enhancing G0/G1 cell cycle arrest. These observations provide a new guiding strategy for the clinical application of miRNA therapy in tumor treatment. J. Cell. Physiol. 230: 2476–2488, 2015. © 2015 Wiley Periodicals, Inc.
Region sampling for robust and rapid autofocus in microscope
Authors: Gu Chao‐Chen , Wu Kai‐Jie , Hu Jie , Hao Cheng , Guan Xin‐Ping
Published: March 2015

This paper proposes a region sampling based autofocus method for rapid and robust autofocus in microscope. Image content and region size are considered in region sampling criteria. An intelligent search algorithm which employs quartering hill climbing search and golden section search is developed, in which rule‐based evaluation of sampled focusing regions is applied. Experimental results demonstrate that the proposed method can significantly improve the performance of image‐based autofocus. Microsc. Res. Tech. 78:382–390, 2015. © 2015 Wiley Periodicals, Inc.
Navigating venous access: A guide for hospitalists
Authors: Simonov Michael , Pittiruti Mauro , Rickard Claire M. , Chopra Vineet
Published: March 2015

Venous access is the foundation for safe and effective hospital‐based care. Inpatient providers must have a deep knowledge of the different types of venous access devices (VADs), their relative indications, contraindications, and appropriateness. However, such knowledge is difficult to come by and usually only gleaned through years of clinical experience. To bridge this gap, we provide an in‐depth summary of the relevant anatomical considerations, physical characteristics, advantages, and disadvantages of VADs commonly used in the hospital setting. In doing so, we seek to improve the safety and share the science of vascular access with frontline clinicians. To aid decision‐making, we conclude by operationalizing the available data through algorithms that outline appropriate vascular access for the hospitalized patient. Journal of Hospital Medicine 2015;10:471–478. © 2015 Society of Hospital Medicine