bluuebunny/crossref_metadata_2025 huggingface dataset:
Scale‐up of cell culture bioreactors using biomechatronic design
Authors: Mandenius Carl‐Fredrik , Björkman Mats
Published: March 2012

Scale‐up of cell culture bioreactors is a challenging engineering work that requires wide competence in cell biology, mechanical engineering and bioprocess design. In this article, a new approach for cell culture bioreactor scale‐up is suggested that is based on biomechatronic design methodology. The approach differs from traditional biochemical engineering methodology by applying a sequential design procedure where the needs of the users and alternative design solutions are systematically analysed. The procedure is based on the biological and technical functions of the scaled‐up bioreactor that are derived in functional maps, concept generation charts and scoring and interaction matrices. Basic reactor engineering properties, such as mass and heat transfer and kinetics are integrated in the procedure. The methodology results in the generation of alternative design solutions that are thoroughly ranked with help of the user needs. Examples from monoclonal antibodies and recombinant protein production illuminate the steps of the procedure. The methodology provides engineering teams with additional tools that can significantly facilitate the design of new production methods for cell culture processes.
Product Loss Minimization of an Integrated Cryogenic Separation System
Authors: Yang X. , Xu Q.
Published: March 2012

The integrated cold box and demethanizer system as one of the most critical production sections in an ethylene plant couples multistage refrigeration and cryogenic separation to extract hydrogen and methane from the cracked gas feed. Ethylene and the heavier components are liquefied for recovery in the downstream process. During separation, ethylene contained in the methane and hydrogen streams is accounted as the product loss which in reality is significant. To reduce the ethylene loss with energy consumption consideration, a systematic methodology has been developed to optimize the process operation of the integrated cold box and demethanizer system. It covers rigorous simulation model development and validation, sensitivity analysis, operational optimization, and result analysis. The optimization results demonstrate the significant economic benefits of the proposed methodology.
Determination of Gallic Acid by Flow Injection Analysis Based on Luminol‐AgNO3‐Ag NPs Chemiluminescence System
Authors: Li Shifeng , Sun Huimin , Wang Dong , Qian Li , Zhu Yan , Tao Shanjun
Published: March 2012

A novel flow injection procedure has been developed for the determination of gallic acid based on the enhancement function for luminol‐AgNO3‐Ag NPs chemiluminescence (CL) system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV‐vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sensitive with a detection limit of 5×10−10 g·mL−1 and a linear range of 8.0×10−10–1.0×10−7 g·mL−1. The relative standard deviation (RSD) is 1.3% for eleven measurements of 5×10−8 g·mL−1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine–Jianmin Yanhou tablets and synthesized samples.
Synthesis of Conjugated Hyperbranched Polytriazoles Containing Truxene Units by Click Polymerization
Authors: Li Dongzhi , Wang Xin , Jia Yutao , Wang Aiqing , Wu Yonggang
Published: March 2012

It has been a challenge to synthesize high molecular weight and soluble conjugated hyperbranched poly(1,2,3‐triazole)s (hb‐PTAs). In this paper a series of soluble hyperbranched polytriazoles, whose number‐average molecular weight (Mn) and polydispersity index ranged in (1.2–3.3)×104 and 1.7–3.0, respectively, were synthesized with A2+B3 approach. In the polymerization process, diazides A1–A4 and triyne B1 were used as A2 and B3 monomers; Cu(I)‐catalyst, THF and water were used as their reaction system. At room temperature the final molecular weight could be controlled through reaction time, so finally we obtained soluble conjugated hyperbranched poly(1,2,3‐triazole)s hb‐PTAs (1–4). The polymers were soluble in common organic solvents, and all emitted blue light; the films of polymers emitted yellow and blue light, due to the difference in the aggregation of their chromophoric units in the solid state. The thermal properties of the final copolymers were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
Design, Synthesis and Biological Activities of Novel Benzoyl Hydrazines Containing Pyrazole
Authors: Yan Tao , Yu Shujing , Liu Pengfei , Liu Zhuo , Wang Baolei , Xiong Lixia , Li Zhengming
Published: March 2012

In search of environmentally benign compounds with high biological activity, low toxicity and low resistance, 8 novel benzoyl hydrazines containing pyrazole were designed and synthesized. All compounds were characterized by 1H NMR spectra and HRMS. The preliminary results of biological activity assessment indicated that most of title compounds exhibited certain insecticidal activities against Mythimna separata Walker at 200 mg·L−1 but excellent fungicidal activities against six fungus at 50 mg·L−1, which were better than the control.
Frizzled receptors in neurons: From growth cones to the synapse
Authors: Varela‐Nallar Lorena , Ramirez Valerie T. , Gonzalez‐Billault Christian , Inestrosa Nibaldo C.
Published: March 2012

The Wnt signaling pathway has been implicated in several different aspects of neural development and function, including dendrite morphogenesis, axonal growth and guidance, synaptogenesis and synaptic plasticity. Here, we studied several Frizzled Wnt receptors and determined their differential expression during hippocampal development. In cultured hippocampal neurons, the cellular distributions of Frizzleds vary greatly, some of them being localized at neurites, growth cones or synaptic sites. These findings suggest that the Wnt signaling pathway might be temporally and spatially fine tuned during the development of neuronal circuits through specific Frizzled receptors. © 2012 Wiley Periodicals, Inc
ERBB2 overexpression triggers transient high mechanoactivity of breast tumor cells
Authors: Martin Mireille , Müller Karla , Cadenas Cristina , Hermes Matthias , Zink Mareike , Hengstler Jan G. , Käs Josef A.
Published: March 2012

Biomechanical properties of tumor cells play an important role for the metastatic capacity of cancer. Cellular changes of viscoelastic features are prerequisite for cancer progression since they are essential for proliferation and metastasis. However, only little is known about the way how expression of oncogenes influences these biomechanical properties. To address this aspect we used a breast cancer cell line with inducible expression of an oncogenic version of ERBB2. ERBB2 is known to be correlated with bad prognosis in breast cancer. Cell elasticity was determined by the Optical Stretcher, where suspended cells are deformed by two slightly divergent laser beams. We found that induction of ERBB2 caused remarkable biomechanical alterations of the MCF‐7 cells after 24 h: the cells actively contracted in response to mechanical stimuli, a phenomenon known as mechanoactivation. After this period, as the cells became senescent, the mechanoactivity returned to control levels. Time‐resolved gene array analysis revealed that mechanoactivation was accompanied by temporal upregulation of 46 cytoskeletal genes. A possible role of these genes in tumor progression was investigated by expression analyses of 766 breast cancer patients. This showed an association of 12 out of these 46 genes with increased risk of metastasis. Our results demonstrate that overexpression of ERBB2 causes mechanoactivation of tumor cells, which may enhance tumor cell motility fostering distant metastasis. © 2012 Wiley Periodicals, Inc.
Interplay between H‐Bonding and Alkyl‐Chain Ordering in Self‐Assembly of Monodendritic L‐Alanine Derivatives
Authors: Anokhin Denis V. , Lejnieks Jānis , Mourran Ahmed , Zhu Xiaomin , Keul Helmut , Möller Martin , Konovalov Oleg , Erina Natalia , Ivanov Dimitri A.
Published: March 2012

This paper reports on the synthesis and self‐organizing properties of monodendrons consisting of L‐alanine at the focal point and alkyl chains with different length at the periphery. The structures of thin films and monolayers are studied by temperature‐resolved grazing‐incidence X‐ray diffraction and scanning force microscopy. The interplay between H‐bonding and ordering of the alkyl chains results in a rich temperature‐dependent phase behavior. The monodendrons form H‐bonded stabilized clusters with the number of molecules depending on the length of the aliphatic chains and temperature. The clusters play the role of constitutive units in the subsequent self‐assembly. Short alkyl chains allow the material to form thermodynamically stable crystalline phases. The molecules with longer side groups exhibit additional transitions from the crystalline phase to thermotropic columnar hexagonal or columnar rectangular liquid‐crystalline phases. In monolayers deposited on highly ordered pyrolytic graphite, the materials show ordering similar to thin films. However, for the compound bearing hexadecyl chains the affinity of the alkyl groups to graphite dominates the self‐assembly and thereby allows epitaxial growth of a 2D lattice with flat‐on oriented molecules.
Single‐Walled Carbon Nanotubes as Scaffolds to Concentrate DNA for the Study of DNA–Protein Interactions
Authors: Liu Zunfeng , Galli Federica , Waterreus Willem‐Jan , Meulenbroek Elisabeth , Koning Roman I. , Lamers Gerda E. M. , Olsthoorn René C. L. , Pannu Navraj , Oosterkamp Tjerk. H. , Koster Abraham J. , Dame Remus T. , Abrahams Jan Pieter
Published: March 2012

Genomic DNA in bacteria exists in a condensed state, which exhibits different biochemical and biophysical properties from a dilute solution. DNA was concentrated on streptavidin‐covered single‐walled carbon nanotubes (Strep⋅SWNTs) through biotin–streptavidin interactions. We reasoned that confining DNA within a defined space through mechanical constraints, rather than by manipulating buffer conditions, would more closely resemble physiological conditions. By ensuring a high streptavidin loading on SWNTs of about 1 streptavidin tetramer per 4 nm of SWNT, we were able to achieve dense DNA binding. DNA is bound to Strep⋅SWNTs at a tunable density and up to as high as 0.5 mg mL−1 in solution and 29 mg mL−1 on a 2D surface. This platform allows us to observe the aggregation behavior of DNA at high concentrations and the counteracting effects of HU protein (a histone‐like protein from Escherichia coli strain U93) on the DNA aggregates. This provides an in vitro model for studying DNA–DNA and DNA–protein interactions at a high DNA concentration.
DyeCycle violet used for side population detection is a substrate of P‐glycoprotein
Authors: Boesch Maximilian , Reimer Daniel , Rumpold Holger , Zeimet Alain G. , Sopper Sieghart , Wolf Dominik
Published: March 2012

Cancer stem cells (CSC) are increasingly recognized as key target cells for cancer therapy because they are both tumorigenic and chemoresistant and, therefore, can give rise to recurrent disease. Side population (SP) sorting using an ultraviolet (UV) laser is an established method to isolate CSC based on ABC drug transporter‐dependent (e.g., ABCG2) Hoechst 33342 efflux. We here show that Vybrant® DyeCycle™ Violet (DCV), a DNA‐binding fluorophor allowing SP sorting using a non‐UV laser (such as violet laser), is transported via P‐glycoprotein (PgP). Because PgP might be particularly abundant in multidrug‐resistant cancer cells rather than bona fide CSC, investigators using DCV should be aware that this strategy might also detect PgP‐expressing non‐CSC. © 2012 International Society for Advancement of Cytometry
Latent learning of spatial information is impaired in middle‐aged rats
Authors: Stouffer Eric M. , Heisey Jamie L.
Published: March 2012

The present study determined if the middle age related impairment that occurs with nonspatial latent learning also occurs in spatial latent learning. Thirty young (3‐months‐old) and 30 middle‐aged (12‐months‐old) male Sprague–Dawley rats were given either pre‐exposure to spatial cues surrounding a Barnes maze (SpatialPX), or pre‐exposure to just the maze (MazePX). They were then given 10 training trials in which they had to find a hidden escape box while experiencing an aversive environment produced by bright lights and wind. Results showed that young rats given the SpatialPX condition demonstrated faster escape latencies and fewer errors than young rats given the MazePX condition. However, middle‐aged rats given the SpatialPX condition did not show this improved performance. These findings indicate that the middle age learning deficit is not task specific, but rather is a general impairment in latent learning, possibly due to the early degeneration of the entorhinal cortex. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 309–315, 2013
Structural Study of the Lipopolysaccharide O‐Antigen Produced by the Emerging Cystic Fibrosis Pathogen Pandoraea pulmonicola
Authors: Di Lorenzo Flaviana , Silipo Alba , Costello Anne , Sturiale Luisa , Garozzo Domenico , Callaghan Máire , Lanzetta Rosa , Parrilli Michelangelo , McClean Siobhán , Molinaro Antonio
Published: March 2012

This is the first report on the molecular structure of the O‐chain of the lipopolysaccharide produced by the emerging and highly virulent clinical isolate Pandoraea pulmonicola strain LMG 18108, an opportunistic human pathogen in cystic fibrosis patients. Monosaccharide analysis and 2D NMR spectroscopy revealed a novel polysaccharide, the structure of which consists of the trisaccharide repeating unit [→2‐β‐D‐Quip3NAcyl‐(1→4)‐α‐D‐GalpNAc‐(1→3)‐α‐D‐GlcpNAc‐1→]n. The quinovosamine residue was found to be linked by a very unusual acyl substituent, a five‐membered‐ring acyl residue, the 3‐hydroxy‐2,3‐dimethyl‐5‐oxoprolyl group.
Simultaneous Determination of Trace Uranium(VI) and Cadmium(II) by Adsorptive Stripping Voltammetry in the Presence of Cupferron as a Complexing Agent
Authors: Grabarczyk Malgorzata , Koper Anna
Published: March 2012

The application of cupferron as a complexing agent for a simultaneous voltammetric determination of U(VI) and Cd(II) in a single scan in environmental water samples has been developed. Optimal conditions were found to be: 0.05 mol L−1 acetate buffer (pH 5.3) as a supporting electrolyte, 1×10−3 mol L−1 cupferron, the accumulation potential −0.25 V, the accumulation time 30 s. The linear range of uranium(VI) and cadmium(II) were observed over the concentration range from 1×10−8 mol L−1 to 5×10−7 mol L−1 and from 2.5×10−9 mol L−1 to 2×10−7 mol L−1, respectively. The procedure was applied to the determination in natural water samples.
Lysine and Arginine Oligopeptides Tagged with Anthraquinone: Electrochemical Properties
Authors: Czupryniak Justyna , Niedziałkowski Paweł , Karbarz Marcin , Ossowski Tadeusz , Stojek Zbigniew
Published: March 2012

New, electroactive, positively charged peptides consisting of either L‐lysine or L‐arginine and containing one or two anthraquinone units in the structure were synthesized. Electrochemical properties of the synthesized compounds were examined by cyclic‐, normal pulse‐ and microelectrode voltammetries. Spectroscopic and potentiometric methods were used to characterize such properties of the new peptides as: pKa, diffusion coefficients and formal potentials in water and DMSO. The obtained results show that the number of noninteracting, anthraquinone units incorporated into one peptide chain leads to proportional increase of height of voltammetric and spectroscopic signals.
The tumour suppressor and chromatin‐remodelling factor BRG1 antagonizes Myc activity and promotes cell differentiation in human cancer
Authors: Romero Octavio A. , Setien Fernando , John Sam , Gimenez‐Xavier Pol , Gómez‐López Gonzalo , Pisano David , Condom Enric , Villanueva Alberto , Hager Gordon L. , Sanchez‐Cespedes Montse
Published: March 2012

BRG1, a member of the SWI/SNF complex, is mutated in cancer, but it is unclear how it promotes tumourigenesis. We report that re‐expression of BRG1 in lung cancer cells up‐regulates lung‐specific transcripts, restoring the gene expression signature of normal lung. Using cell lines from several cancer types we found that those lacking BRG1 do not respond to retinoic acid (RA) or glucocorticoids (GC), while restoration of BRG1 restores sensitivity. Conversely, in SH‐SY5Y cells, a paradigm of RA‐dependent differentiation, abrogation of BRG1 prevented the response to RA. Further, our data suggest an antagonistic functional connection between BRG1 and MYC, whereby, refractoriness to RA and GC by BRG1 inactivation involves deregulation of MYC activity. Mechanistically, some of these effects are mediated by BRG1 binding to MYC and MYC‐target promoters. The BRG1‐MYC antagonism was also evident in primary tumours. Finally, BRG1 restoration significantly dampened invasion and progression and decreased MYC in lung cancer cells orthotopically implanted in nude mice. Thus, BRG1 inactivation enables cancer cells to sustain undifferentiated gene expression programs and prevent its response to environmental stimuli.
Tabu search for dynamic spectrum allocation in cellular networks
Authors: Kamal Hany , Coupechoux Marceau , Godlewski Philippe
Published: March 2012

In this paper, we present and analyse a Tabu Search algorithm for Dynamic Spectrum Allocation in cellular networks. We study a case where an operator is providing packet services to the end users. The objective of the cellular operator is to maximise its reward while taking into account the trade‐off between the spectrum cost and the revenues obtained from end users. These revenues are modelled here as an increasing function of the achieved throughput. The cost is proportional to the bandwidth of the spectrum leased to the regulator or some spectrum broker. Results show that the algorithm allows the operator to increase its reward by taking advantage of the spatial and temporal heterogeneities of the traffic in the network, rather than assuming homogeneous traffic for its radio resource allocation. Our Tabu Search‐based Dynamic Spectrum Allocation algorithm is efficient in terms of the required memory space and convergence speed. Results show that the algorithm is fast enough to suit a dynamic context. Copyright © 2012 John Wiley & Sons, Ltd.
Caloplaca lacinulata rediscovered for the lichen flora of South Korea
Authors: Joshi Yogesh , Andreev Mikhail , Hur Jae‐Seoun
Published: March 2012

The existence of the lichen species Caloplaca lacinulata (Hue) Zahlbr. (1930) [1931] is confirmed after a gap of about 100 years. The taxon was first described by Hue (1913), growing over granite rocks nearly Seoul. Its rediscovery is documented by a specimen recently collected in Mt. Sorak, extending its distribution within South Korea. A brief description and illustrations are provided for the species. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Association of cerebral small vessel disease with delusions in patients with Alzheimer's disease
Authors: Ogawa Yusuke , Hashimoto Mamoru , Yatabe Yusuke , Kaneda Keiichiro , Honda Kazuki , Yuuki Seiji , Hirai Toshinori , Ikeda Manabu
Published: March 2012

Background

Cerebral small vessel disease (SVD) is frequently observed in patients with Alzheimer's disease (AD). However, the association between SVD and clinical symptoms exhibited by patients with AD remains unclear. This study examined the association of SVD as observed on magnetic resonance imaging (MRI) with behavioural and psychological symptoms of dementia and cognitive function of patients with probable AD.

Methods

A total of 163 consecutive patients (55 men, 108 women) with probable AD were included in this cross‐sectional study of a prospective cohort. Patients were divided into two groups based on the presence or absence of cerebral SVD [white matter hyperintensities (WMH) grade 0/1 (Fazekas scale) and no lacunes: SVD absent, WMH grade 2/3 (Fazekas scale) or the number of lacunes ≥1: SVD present]. Cognitive functions were assessed using the Mini mental state examination, word recall and recognition subtests in the Alzheimer's Disease Assessment Scale—Cognitive Subscale, as well as the letter fluency task and the category fluency task. Psychiatric symptoms were rated according to Neuropsychiatric Inventory.

Results

Patients with probable AD with cerebral SVD had significantly more delusions and depression than those without SVD. No significant differences were observed in other neuropsychiatric symptoms, MMSE or word recall and recognition tests between both groups.

Conclusions

Our results suggest that cerebral SVD observed on MRI of patients with AD is associated with delusions and depression. Copyright © 2012 John Wiley & Sons, Ltd.
Improvement of the cytocompatibility of electrospun poly[(R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyvalerate] mats by Ecoflex
Authors: Wang Anhui , Gan Yunna , Yu Hao , Liu Yuan , Zhang Min , Cheng Baixiang , Wang Fang , Wang Huixia , Yan Juanjuan
Published: March 2012

Poly[(R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyvalerate] (PHBV) is a nature‐derived polyester with potential application in tissue engineering scaffolds. However, PHBV is associated with disadvantages including high brittleness, slow degradation, high hydrophobicity, and unsatisfactory biocompatibility. In this study, we sought to improve the properties of PHBV by blending it with Ecoflex, a synthetic biopolyester with a high flexibility, fast degradation, and comparatively higher hydrophilicity. PHBV was codissolved with Ecoflex in dichloromethane at different mass ratios (PHBV/Ecoflex: 100/0, 70/30, 50/50, and 30/70) and electrospun into mats. Compared with the pure PHBV mat, the Ecoflex‐containing mats showed decreased contact angles with phosphate‐buffered saline (PBS), accelerated weight loss in PBS, and increased strain at break with increasing Ecoflex mass ratios. In vitro cell culture also showed significantly improved adhesion and proliferation of human bone marrow stroma cells with the introduction of Ecoflex. Blending PHBV with Ecoflex is a simple and effective method to improve the chemical, mechanical, and biological properties of PHBV simultaneously and thereby to expedite its application in tissue engineering. To our knowledge, this is the first report showing the biocompatibility of Ecoflex‐containing materials with human cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Effect of biological/physical stimulation on guided bone regeneration through asymmetrically porous membrane
Authors: Kim Tae Ho , Oh Se Heang , Na Seung Yeon , Chun So Young , Lee Jin Ho
Published: March 2012

Asymmetrically porous polycaprolactone (PCL)/Pluronic F127 guided bone regeneration (GBR) membranes were fabricated. The top surface of the membrane had nanosize pores (∼10 nm) which can effectively prevent invasion by fibrous connective tissue but permeate nutrients, whereas the bottom surface had microsize pores (∼200 μm) which can enhance the adhesiveness with bone tissue. Ultrasound was applied to a bone morphogenetic protein (BMP‐2)‐immobilized PCL/F127 GBR membrane to investigate the feasibility of using dual biological (BMP‐2) and physical (ultrasound) stimulation for enhancing bone regeneration through the membrane. In an animal study using SD rats (cranial defect model), the bone regeneration behavior that occurred when using BMP‐2‐loaded GBR membranes with ultrasound treatment (GBR/BMP‐2/US) was much faster than when the same GBR membrane was used without the ultrasound treatment (GBR/BMP‐2), as well as when GBR membranes were used without stimulations (GBR). The enhanced bone regeneration of the GBR/BMP‐2/US group can be interpreted as resulting from the synergistic or additive effect of the asymmetrically porous PCL/F127 membrane with unique properties (selective permeability, hydrophilicity, and osteoconductivity) and the stimulatory effects of BMP‐2 and ultrasound (osteoinductivity). The asymmetrically porous GBR membrane with dual BMP‐2 and ultrasound stimulation may be promising for the clinical treatment of delayed and insufficient bone healing. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Student award winner in the undergraduate category for the society of biomaterials 9th World Biomaterials Congress, Chengdu, China, June 1–5, 2012
Authors: Blakney Anna K. , Swartzlander Mark D. , Bryant Stephanie J.
Published: March 2012

Poly(ethylene glycol) (PEG) hydrogels, modified with RGD, are promising platforms for cell encapsulation and tissue engineering. While these hydrogels offer tunable mechanical properties, the extent of the host response may limit their in vivo applicability. The overall objective was to characterize the effects of hydrogel stiffness on the in vitro macrophage response and in vivo host response. We hypothesized that stiffer substrates induce better attachment, adhesion, and increased cell spreading, which elevates the macrophage classically activated phenotype and leads to a more severe foreign body reaction (FBR). PEG‐RGD hydrogels were fabricated with compressive moduli of 130, 240, and 840 kPa, and the same RGD concentration. Hydrogel stiffness did not impact macrophage attachment, but elicited differences in cell morphology. Cells retained a round morphology on 130 kPa substrates, with localized and dense F‐actin and localized αV integrin stainings. Contrarily, cells on stiffer substrates were more spread, with filopodia protruding from the cell, a more defined F‐actin, and greater αV integrin staining. When stimulated with lipopolysaccharide, macrophages had a classical activation phenotype, with increased expression of TNF‐α, IL‐1β, and IL‐6, however the degree of activation was significantly reduced with the softest hydrogels. A FBR ensued in response to all hydrogels when implanted subcutaneously in mice, but 28 days postimplantation the layer of macrophages at the implant surface was significantly lower in the softest hydrogels. In conclusion, hydrogels with lower stiffness led to reduced macrophage activation and a less severe and more typical FBR, and therefore are more suited for in vivo tissue engineering applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
The First Synthesis of Natural Occurring Juncaceae Coumarin, 9‐Hydroxy‐8‐methyl‐3H‐benzo[f]chromen‐3‐one, Featuring a One‐pot Rearrangement and Aromatization Cascade
Authors: Hon Yung‐Son , Hong Ya‐Chun , Hong Bor‐Cherng , Liao Ju‐Hsiou
Published: March 2012

The synthesis of benzocoumarins from β‐tetralones has been achieved via two pathways in the first total synthesis of the Juncaceae natural product, 9‐hydroxy‐8‐methyl‐3H‐benzo[f]chromen‐3‐one, featuring a one‐pot rearrangement and aromatization cascade.
Conformational Analysis of trans‐2,11‐Dithia‐4e,5,6,7e,8,9‐hexahydro[3.3]paracyclophane Using VT‐NMR
Authors: Yang Ya‐Chen , Lin Chen‐Huei , Lin Lee‐Huei , Lin Shaw‐Tao
Published: March 2012

The conformation of trans‐2,11‐dithia‐4e,5,6,7e,8,9‐hexahydro[3.3]paracyclophanes (5, tDTHHPCP) was investigated by using 1H NMR analysis under variable‐temperature condition. Based on the dynamic 1H NMR behavior along with a structure obtained from simulation using the MM2 method, it has been deduced that 5 occurs preferentially in conformer 5a in CD2Cl2 solution, which the two sulfur atoms are situated as the chair form and cyclohexano unit as a distorted boat form. The energy barrier (ΔG‡) for the inversion of the bridge (‐CH2SCH2‐) has been estimated to be 11.6 kcal mol‐1 (600 MHz, Tc = ‐30 °C). The proton chemical shifts are assigned for the individual hydrogen according to the spectra obtained at ‐70 °C.
Synthesis of Chiral Pyrrolidine Isostere Inserted into Pyrrole Polyamide Skeleton
Authors: Lin Chun‐Yu , Yang Ya‐Ting , Ong Chi Wi
Published: March 2012

An efficient and general route towards the synthesis of a series of chiral pyrrolidine pyrrole polyamide distamycin analogues starting from (L)‐hydroxyproline is described. The binding abilities of these chiral pyrrolidine containing molecules to calf thymus DNA were evaluated by duplex DNA melting temperature analysis. The results revealed that both the chirality at the pyrrolidine ring and the site of incorporation plays an important role for binding at the duplex DNA.
Synthesis and Spectroscopic Characterization of Dual Absorption BODIPY Type Dyes and their Light Harvesting Application in Polymer‐Based Bulk Hetrojunction Organic Photovoltaics
Authors: Chi Chih‐Chin , Huang Yu‐Jui , Chen Chin‐Ti
Published: March 2012

We reported the synthesis and characterization of two new BODIPY type dyes with fluorine‐bridged two chromophores, boron‐dipyrromethene (BDP) and boron‐diindomethene (BDI). Each of BODIPY dyes 7a and 7b has two strong absorption bands around 500 and 600 nm bearing high extinction coefficients (76,000 M‐1cm‐1 for 7a and 71,000 M‐1cm‐1 for 7b at 501 nm; 115,000 M‐1cm‐1 for 7a and 110,000 M‐1cm‐1 for 7b at 603 nm). For light harvesting enhancement of solar cell, we have fabricated bulk heterojunction photovoltaics with various weight percentages of 7a as dopant dye in P3HT:PCBM blends in attempting to improve power conversion efficiency of solar energy.
A Gold(I) Complex Based on 1,8‐Naphthyridine Functionalized N‐Heterocyclic Carbene (NHC) and Its Catalytic Activity
Authors: Liu Zu‐Yin , Liu Shiuh‐Tzung
Published: March 2012

A gold complex containing 2,7‐bis(mesitylimidazolylidenyl)naphthyridine (NHC‐NP) has been synthesized. Thus, reaction of [{Ag3(NHC‐NP)2}(PF6)3] with [Au(Me2S)Cl] provided an unusual digold complex bridged by two NHC‐NP, forming a 20‐membered dinuclear metallacycle [{Au2(NHC‐NP)2Cl2}(PF6)2] (2) in high yield. This complex was characterized by spectroscopic and elemental analysis. This gold complex is active for the hydrolysis of 2,2,5‐trimethyl‐1,3‐dioxane‐5‐methanol and can be recycled without losing the activity.
Synthesis of a Versatile Probe for Analysis of Cytoplasmic Peptide‐N‐Glycanase
Authors: Masuda Mizuho , Miyazawa Shinpei , Ito Yukishige , Matsuo Ichiro
Published: March 2012

A clickable alkyne tagged chloroacetamidyl chitobiose derivative was synthesized as a potential inhibitor of cytoplasmic peptide‐N‐glycanase (PNGase). Construction of a chitobiose structure containing both alkyne and azide functional groups was performed using a thioglycoside donor having a triisopropylsilyl (TIPS) protected alkyne group and a glycosyl azide acceptor. The resultant chitobiosyl azide derivative was reduced to the corresponding glycosyl amine and a chloroacetyl group was introduced. Finally, removal of the TIPS group using tetrabutylammonium fluoride (TBAF) gave the target compound. We conjugated the dansyl derivative, using click conditions and obtained the fluorescent labeled disaccharide derivative, selectively. Our probe can easily lead to a variety of compounds and should help in the understanding of the biological functions of cytoplasmic PNGase.
FeCl3 Catalyzed Barbier Homocoupling Reaction for Synthesis of Symmetric Biaryls
Authors: Lee Adam Shih‐Yuan , Chen Pin‐Lung , Chang Yu‐Ting , Tsai Heng‐Tser
Published: March 2012

A series of biaryls and biheteroaryls were synthesized by the Barbier reaction of aryl bromide with magnesium powder and 1,2‐dibromoethane in the presence of FeCl3 in THF under reflux reaction condition. The catalytic system differentiates itself from other homocoupling reactions catalyzed by iron salts in that it requires neither the preliminary preparation of Grignard reagent nor the addition of an oxidant.
Development of a Plate‐Based Assay Platform to Monitor Cellular SHP2 Phosphatase Activity During Erythroid Differentiation
Authors: Chu Chi‐Yuan , Kuo Chun‐Chen , Chen Mei‐Hsiao , Chen Kuan‐Ju , Lo Lee‐Chiang , Lin Jing‐Jer
Published: March 2012

In light of the growing interest in understanding the roles of protein tyrosine phosphatases (PTPs) in the complicated signaling pathways, convenient methods to profile and analyze PTP activities in various cellular processes are in high demand. We previously demonstrated a two‐step assay platform that combined the use of a universal activity‐based probe with a PTP‐specific antibody, by which the designated PTP activity in a cellular event could be successfully determined. Here, we describe an improved plate‐based assay platform by replacing the immunoprecipitation step with a simpler immunocapture step using an antibody on a plate. An assay protocol targeting SHP2 activity was thus established and a universal probe with a sulforhodamine B tag was used to afford a direct fluorescent readout. The protocol was employed for the monitoring of SHP2 activities during K562 erythroid differentiation. Comparative study using the previous protocol was also conducted. Both PTP assay protocols consistently showed that SHP2 was activated during K562 erythroid differentiation.
AN INVESTIGATION OF VOLUNTEER‐STUDENT RELATIONSHIP TRAJECTORIES WITHIN SCHOOL‐BASED YOUTH MENTORING PROGRAMS
Authors: Pryce Julia , Keller Thomas E.
Published: March 2012

This prospective, mixed‐method study investigates the development of school‐based mentoring relationships using direct observations, in‐depth interviews, and questionnaires from the perspective of mentors and students. A pattern‐oriented analysis of qualitative data explores the diversity observed in the life‐course of mentor‐student relationships. Systematic variation in developmental trends across relationships revealed four distinctive groupings. Some relationships showed progressive improvement in strength and quality. Others started well but reached a plateau and did not become particularly close. A third group struggled throughout to make a connection. Finally, some relationships succeeded after a breakthrough to overcome their challenges. These inductively derived categories are corroborated and supplemented with quantitative data regarding relationship quality. The study reveals the heterogeneity of relationship trajectories within school‐based mentoring programs.
NURTURING HUMAN POTENTIAL IN THE CONTEXT OF SCHOOLING: THE LEGACY OF SEYMOUR B. SARASON
Authors: Weinstein Rhona S.
Published: March 2012

This paper is a slightly revised version of the presentation at the SCRA Biennial session, “Seymour Sarason in Memorial: Prospects for Community and Social Change,” Chicago, June 18, 2011.
REFLECTIONS ON THE CREATION OF SETTINGS AND THE FUTURE SOCIETIES: THE ROSES AND THORNS
Authors: Langhout Regina
Published: March 2012

The presentation below was part of the 2011 Division 27 SCRA conference panel, “Seymour Sarason in Memorial: Prospects for Community and Social Change Innovative Session.”
SERVICE CONTENT AS A DETERMINANT OF HOMELESS ADULTS’ PERCEPTIONS OF PROGRAM EFFICACY
Authors: Sosin Michael , George Christine , Grossman Susan
Published: March 2012

This work analyzes the relationship between the services clients receive in treatment programs and client ratings of program efficacy. It relies on data from a random sample of clients served by Chicago's homelessness system (N = 554). Regressions utilizing that data suggest that ratings of program efficacy are positively predicted by program ambiance, the ambiance of referral arrangements, residence in programs providing housing, and receipt of employment services. The measures of ambiance are predicted by receipt of professional services and help in locating housing. Receipt of advocacy services does not predict ratings of program efficacy nor ambiance; receipt of tangible services is negatively related to ratings of program efficacy. Results suggest that clients rate highly programs that have a positive ambiance or that provide services that clients view as immediately helpful for solving long‐term needs. Clients thereby discount services known to contribute to the amelioration of homelessness.
Environmental effects in kelvin force microscopy of modified diamond surfaces
Authors: Araujo W.W.R. , Salvadori M.C. , Teixeira F.S. , Cattani M. , Brown I.G.
Published: March 2012

We have explored the effects of atmospheric environment on Kelvin force microscopy (KFM) measurements of potential difference between different regions of test polycrystalline diamond surfaces. The diamond films were deposited by microwave plasma‐assisted chemical vapor deposition, which naturally produces hydrogen terminations on the surface of the films formed. Selected regions were patterned by electron‐beam lithography and chemical terminations of oxygen or fluorine were created by exposure to an oxygen or fluorine plasma source. For KFM imaging, the samples were mounted in a hood with a constant flow of helium gas. Successive images were taken over a 5‐h period showing the effect of the environment on KFM imaging. We conclude that the helium flow removes water molecules adsorbed on the surface of the samples, resulting in differences in surface potential between adjacent regions. The degree of water removal is different for surfaces with different terminations. The results highlight the importance of taking into account the atmospheric environment when carrying out KFM analysis. © 2012 Wiley Periodicals, Inc.
Pedotransfer functions for water retention and unsaturated hydraulic conductivity of forest soils
Authors: Puhlmann Heike , von Wilpert Klaus
Published: March 2012

The hydraulic properties of soils, i.e., their ability to store and conduct water, mainly govern the availability of soil water for plants. Information on the hydraulic properties is needed, e.g., for the quantification of drought risk at a given site. Furthermore, knowledge of the water transport is the precondition for the estimation of element fluxes in the soil, e.g., when predicting element leaching from the root zone to the groundwater. For forest soils, only few systematic investigations of their hydraulic properties exist. Within the 2nd forest‐soil survey of Germany, soil samples were taken along a regular 8 km × 8 km grid in the forests of the State of Baden‐Württemberg and the hydraulic properties were estimated in the laboratory by multistep outflow experiments. Besides the soil‐hydraulic measurements, numerous additional soil chemical and physical analyses were carried out and comprehensive profile descriptions were compiled and integrated in a hydraulic database. Based on this database, multiple‐linear‐regression techniques were used to develop pedotransfer functions for the water‐retention curve and the unsaturated‐hydraulic‐conductivity curve using the parametric models of Mualem/van‐Genuchten. Our work fills a gap since to our knowledge, no pedotransfer functions for the unsaturated hydraulic conductivity for forest soils exist so far. The predictive accuracy of the established pedotransfer functions, both for the water‐retention curve and the hydraulic‐conductivity curve, is in the range of (and in some cases better than) other published pedotransfer functions that were mostly derived for agricultural soils.
IMPLICATIONS OF COVER CROPS FOR SOIL QUALITY AND GEODIVERSITY IN A HUMID‐TEMPERATE REGION IN THE MIDWESTERN USA
Authors: Stavi I. , Lal R. , Jones S. , Reeder R. C.
Published: March 2012

Winter cover cropping plays an important role in conservation farming. In the Midwest region of the USA, strips planted with Austrian winter peas [AWP (Pisum sativum L.)], radishes [RAD (Raphanus sativus L.)], and a mixed cover of both cultivars (MIX) were compared during the spring season to determine their impact on the soil quality at 0–5 and 5–10 cm depths. The treatments RAD, AWP, and MIX had the highest, intermediate, and lowest soil bulk density impacts (1·67, 1·52, and 1·50 Mg m−3, respectively). An opposite trend was observed for the concentrations of soil organic carbon (15·9, 17·6, and 19·4 g kg−1, respectively) and total nitrogen (1·5, 1·7, and 2·8 g kg−1, respectively), the calcium exchange capacity (8·6, 9·5, and 11·4 cmol+c kg−1, respectively), and earthworm density (85, 221 and 226 per m2 x 0·15 m, respectively). The AWP, MIX, and RAD resulted in the highest, intermediate, and lowest water stable aggregates (91·6, 87·4, and 79·9 per cent, respectively), mean weight diameter of aggregates (3·4, 2·7, and 2·1 mm, respectively), saturated hydraulic conductivity (15·7, 13·0, and 6·3 cm h−1, respectively), and intrinsic permeability (1·69, 1·37, and 0·70 cm2 10−10, respectively). The AWP and RAD treatments resulted in a similar C:N ratio (10·5), which was larger than associated with MIX (7·2). Overall, AWP and MIX had a larger positive impact on soil quality than RAD did, and the impact was greater at the 0–5 than the 5–10 cm depth. This indicates the suitability of the various cover crops for improving the soil quality and restoring geodiversity. Copyright © 2012 John Wiley & Sons, Ltd.
Betulinic acid decreases ER‐negative breast cancer cell growth in vitro and in vivo: Role of Sp transcription factors and microRNA‐27a:ZBTB10
Authors: Mertens‐Talcott Susanne U. , Noratto Giuliana D. , Li Xiangrong , Angel‐Morales Gabriela , Bertoldi Michele C. , Safe Stephen
Published: March 2012

Betulinic acid (BA), a pentacyclic triterpenoid isolated from tree bark is cytotoxic to cancer cells. There is evidence that specificity proteins (Sps), such as Sp1, Sp3, and Sp4, are overexpressed in tumors and contribute to the proliferative and angiogenic phenotype associated with cancer cells. The objective of this study was to determine the efficacy of BA in decreasing the Sps expression and underlying mechanisms. Results show that BA decreased proliferation and induced apoptosis of estrogen‐receptor‐negative breast cancer MDA‐MB‐231 cells. The BA‐induced Sp1, Sp3, and Sp4 downregulation was accompanied by increased zinc finger ZBTB10 expression, a putative Sp‐repressor and decreased microRNA‐27a levels, a microRNA involved in the regulation of ZBTB10. Similar results were observed in MDA‐MB‐231 cells transfected with ZBTB10 expression plasmid. BA induced cell cycle arrest in the G2/M phase and increased Myt‐1 mRNA (a microRNA‐27a target gene), which causes inhibition in G2/M by phosphorylation of cdc2. The effects of BA were reversed by transient transfection with a mimic of microRNA‐27a. In nude mice with xenografted MDA‐MB‐231 cells, tumor size and weight were significantly decreased by BA treatment. In tumor tissue, ZBTB10 mRNA was increased while mRNA and protein of Sp1, Sp3 and Sp4, as well as mRNA of vascular endothelial growth factor receptor (VEGFR), survivin and microRNA‐27a were decreased by BA. In lungs of xenografted mice, human β2‐microglobulin mRNA was decreased in BA‐treated animals. These results show that the anticancer effects of BA are at least in part based on interactions with the microRNA‐27a‐ZBTB10‐Sp‐axis causing increased cell death. © 2012 Wiley Periodicals, Inc.
Methionine synthase and thymidylate synthase gene polymorphisms and colorectal adenoma risk: The self defense forces study
Authors: Yoshimitsu Shinichiro , Morita Makiko , Hamachi Tadamichi , Tabata Shinji , Abe Hiroshi , Tajima Osamu , Uezono Kousaku , Ohnaka Keizo , Kono Suminori
Published: March 2012

Folate‐mediated one‐carbon metabolism has been implicated in colorectal carcinogenesis. We investigated associations of functional genetic polymorphisms of methionine synthase (MTR), MTR reductase (MTRR), and thymidylate synthase (TS) with colorectal adenomas. The study subjects were 455 cases of colorectal adenomas and 1052 controls with no polyp at colonoscopy. Genotypes were determined for MTR A2756G, MTRR A66G and two polymorphisms in the TS gene, 28‐bp tandem repeat polymorphism in the promoter enhancer region (TSER) and 6‐bp deletion polymorphism at position 1494 in the 3′ untranslated region (TS 1494del6). We also examined the alcohol–genotype and gene–gene interactions on adenoma risk. The GG genotype of MTR A2756G was associated with an increased risk of colorectal adenomas; odds ratios for AG and GG versus AA genotype were 0.99 (95% confidence interval 0.78–1.26) and 1.72 (1.04–2.82), respectively. The increase in the risk associated with MTR 2756GG genotype was evident in men with high alcohol consumption (≥30 mL/d), but not in those with low alcohol consumption (interaction P = 0.03). Men who were homozygous for the TSER double‐repeat allele had a slightly decreased risk of colorectal adenomas as compared with those homozygous for the TSER triple‐repeat allele. Neither MTRR A66G nor TS 1494del6 was associated with colorectal adenomas. There was no measurable interaction either between MTR A2756G and MTRR A66G or between TSER and TS 1494del6. MTR A2756G appears to be associated with colorectal adenoma risk differently according to alcohol consumption. The MTR‐catalyzed reaction may play an important role in the development of colorectal adenomas. © 2012 Wiley Periodicals, Inc.
Matchmaking using Fuzzy Analytical Hierarchy Process, Compatibility Measure and Stable Matching for Online Matrimony in India
Authors: Joshi Kedar , Kumar Sushil
Published: March 2012

Use of online matrimony for matchmaking is rapidly growing in India. One of the major difficulties faced by the users of such websites is the long time taken to realize the matches. We propose an integrated approach to matchmaking in e‐matrimony environment using fuzzy analytical hierarchy process considering multiple criteria involved in the process. The objective of the study is to enable users to search their partners effectively and efficiently and narrow down to the desired matches so that the chances of matchmaking through online portal are maximized. A compatibility index, that is match metric, is developed that enhances the probability of matchmaking with reduction in lead time. Furthermore, Gale‐Shapley stable matching algorithm is used to help customers obtain the desired shortlist of profiles with a suggested stable match. An illustrated hypothetical example of matchmaking using an Indian matrimony portal is presented, and the use of the proposed methodology is demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
Global solutions of a class of discrete‐time backward nonlinear equations on ordered Banach spaces with applications to Riccati equations of stochastic control
Authors: Ungureanu V. M. , Dragan V. , Morozan T.
Published: March 2012

In this paper, we consider the problem of existence of certain global solutions for general discrete‐time backward nonlinear equations, defined on infinite dimensional ordered Banach spaces. This class of nonlinear equations includes as special cases many of the discrete‐time Riccati equations arising both in deterministic and stochastic optimal control problems. On the basis of a linear matrix inequalities approach, we give necessary and sufficient conditions for the existence of maximal, stabilizing, and minimal solutions of the considered discrete‐time backward nonlinear equations. As an application, we discuss the existence of stabilizing solutions for discrete‐time Riccati equations of stochastic control and filtering on Hilbert spaces. The tools provided by this paper show that a wide class of nonlinear equations can be treated in a uniform manner. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of argon on the structure of hydrogenated nanocrystalline silicon deposited from tetrachlorosilane/hydrogen/argon plasma
Authors: Zhang Lin , Gao Junhua , Xiao Jinquan , Wen Lishi , Gong Jun , Sun Chao
Published: March 2012

Hydrogenated nanocrystalline silicon films (nc‐Si:H) have been deposited by the decomposition of tetrachlorosilane (SiCl4) diluted with hydrogen (H2) and argon (Ar) by a plasma‐enhanced chemical vapor deposition (PECVD) method. Basing on the structural characterization of nc‐Si:H, we have found that Ar affects the growth of films deposited at two substrate temperatures (Ts = 250 and 120 °C) in different ways. At Ts = 250 °C, the Ar gas deteriorates the crystallinity of nc‐Si:H, whereas, at Ts = 120 °C, the crystallization of nc‐Si:H films is promoted with increasing argon flow rate (Hf) from 10 to 30 sccm; however, the extremely high Ar dilution adversely affects the ordered structure of films. Meanwhile, the hydrogen concentration in the films is also controlled by Hf. Finally, the effects of Ar in the SiCl4/H2/Ar system have been discussed in related to the equilibrium of atomic hydrogen and ionized argon.