bluuebunny/crossref_metadata_2025 huggingface dataset:
Inefficient Lymph Node Sensitization during Respiratory Viral Infection Promotes IL-17–Mediated Lung Pathology
Authors: Kallal Lara E. , Hartigan Adam J. , Hogaboam Cory M. , Schaller Matthew A. , Lukacs Nicholas W.
Published: August 2010

Development of bronchus-associated lymphoid tissue has been suggested to enhance local antiviral immune responses; however, ectopic lymph node formation often corresponds to chronic inflammatory diseases. These studies investigated the role of ectopic pulmonary lymph nodes upon respiratory syncytial virus (RSV) infection using CCR7-deficient mice, which develop bronchus-associated lymphoid tissue early in life. CCR7−/− mice exhibited impaired secondary lymph node formation, enhanced effector T cell responses and pathogenic mucus production in the lung after RSV infection. IL-17 production from CD4 T cells in CCR7−/− mice was most remarkably enhanced. Wild-type animals reconstituted with CCR7−/− bone marrow recapitulated the pathogenic lung phenotype in CCR7−/− mice, whereas CCR7−/− animals reconstituted with wild-type bone marrow had normal lymph node development, diminished IL-17 production and reduced lung pathology. Mixed bone marrow chimeras revealed an alteration of immune responses only in CCR7−/− T cells, suggesting that impaired trafficking promotes local effector cell generation. Lymphotoxin-α–deficient mice infected with RSV were used to further examine locally induced immune responses and demonstrated increased mucus production and amplified cytokine responses in the lung, especially IL-17. Neutralization of IL-17 in CCR7−/− or in lymphotoxin-α–deficient animals specifically inhibited mucus hypersecretion and reduced IL-13. Thus, immune cell trafficking to secondary lymph nodes is necessary for appropriate cytokine responses to RSV as well as modulation of the local environment.
Distinct Requirements of MicroRNAs in NK Cell Activation, Survival, and Function
Authors: Bezman Natalie A. , Cedars Elizabeth , Steiner David F. , Blelloch Robert , Hesslein David G. T. , Lanier Lewis L.
Published: August 2010

MicroRNAs (miRNAs) are small noncoding RNAs that have recently emerged as critical regulators of gene expression within the immune system. In this study, we used mice with conditional deletion of Dicer and DiGeorge syndrome critical region 8 (Dgcr8) to dissect the roles of miRNAs in NK cell activation, survival, and function during viral infection. We developed a system for deletion of either Dicer or Dgcr8 in peripheral NK cells via drug-induced Cre activity. We found that Dicer- and Dgcr8-deficient NK cells were significantly impaired in survival and turnover, and had impaired function of the ITAM-containing activating NK cell receptors. We further demonstrated that both Dicer- and Dgcr8-dependent pathways were indispensable for the expansion of Ly49H+ NK cells during mouse cytomegalovirus infection. Our data indicate similar phenotypes for Dicer- and Dgcr8-deficient NK cells, which strongly suggest that these processes are regulated by miRNAs. Thus, our findings indicate a critical role for miRNAs in controlling NK cell homeostasis and effector function, with implications for miRNAs regulating diverse aspects of NK cell biology.
Output feedback adaptive command following and disturbance rejection for nonminimum phase uncertain dynamical systems
Authors: Yucelen Tansel , Haddad Wassim M. , Calise Anthony J.
Published: August 2010

In this paper, we develop an output feedback adaptive control framework for continuous‐time nonminimum phase multivariable systems for output stabilization, command following, and disturbance rejection. The approach is based on a nonminimal state space realization that generates an expanded set of states using the filtered inputs and filtered outputs and their derivatives of the original system. Specifically, a direct adaptive controller for the nonminimal state space model is constructed using the expanded states of the nonminimal realization and is shown to be effective for multi‐input, multi‐output nonminimum phase systems with unstable dynamics. The adaptive controller does not require any model information nor does it require information of the system poles and system zeros or estimation of the system Markov parameters. Several illustrative numerical examples are provided to demonstrate the efficacy of the proposed approach. Copyright © 2010 John Wiley & Sons, Ltd.
Threshold computation for fault detection in a class of discrete‐time nonlinear systems
Authors: Khan Abdul Qayyum , Ding Steven X.
Published: August 2010

In this paper, we address the problem of designing robust thresholds for fault detection in discrete‐time nonlinear uncertain systems in the presence of process disturbances. Both constant and dynamic thresholds are proposed. For the computation of constant thresholds, a generalized framework based on signal norms is developed. Different kinds of constant thresholds are studied in the framework proposed. Using linear matrix inequalities (LMI) techniques, algorithms are derived for the computation of these thresholds. Similarly, the dynamic threshold is designed by deriving an inequality on the upper bound of the modulus of the residual signal. This inequality is based on the solution of discrete‐time nonlinear uncertain systems. The simulation examples illustrate that false alarms are successfully eliminated using the proposed thresholds. Copyright © 2010 John Wiley & Sons, Ltd.
FeCl3‐Based Few‐Layer Graphene Intercalation Compounds: Single Linear Dispersion Electronic Band Structure and Strong Charge Transfer Doping
Authors: Zhan Da , Sun Li , Ni Zhen Hua , Liu Lei , Fan Xiao Feng , Wang Yingying , Yu Ting , Lam Yeng Ming , Huang Wei , Shen Ze Xiang
Published: August 2010

Graphene has attracted much attention since its first discovery in 2004. Various approaches have been proposed to control its physical and electronic properties. Here, it is reported that graphene‐based intercalation is an efficient method to modify the electronic properties of few‐layer graphene (FLG). FeCl3 intercalated FLGs are successfully prepared by the two‐zone vapor transport method. This is the first report on full intercalation for graphene samples. The features of the Raman G peak of such FLG intercalation compounds (FLGIC) are in good agreement with their full intercalation structures. The FLGICs present single Lorentzian 2D peaks, similar to that of single‐layer graphene, indicating the loss of electronic coupling between adjacent graphene layers. First principle calculations further reveal that the band structure of FLGIC is similar to single‐layer graphene but with a strong doping effect due to the charge transfer from graphene to FeCl3. The successful fabrication of FLGIC opens a new way to modify properties of FLG for fundamental studies and future applications.
Tailored Remote Photochromic Coloration of in situ Synthesized CdS Quantum Dot Loaded WO3 Films
Authors: Zhao Zhi‐Gang , Liu Zhi‐Fu , Miyauchi Masahiro
Published: August 2010

CdS quantum dot (QD) loaded WO3 films, fabricated by screen printing and short‐time chemical bath deposition (CBD) techniques, have been proven to have an efficient visible‐light‐driven photochromic response. One of the striking features of such a photochromic system is its remote photochromic characteristic. The photogenerated electrons in CdS are injected into WO3 to cause the color change of WO3, while CdS does not show any photochromism. Compared to bare WO3 films, the spectral sensitivity of remote photochromism in the CdS QD loaded WO3 films is red‐shifted. The onset wavelength for remote, the decoloration time for CdS QD loaded WO3 films was found to be significantly shorter than that for bare WO3 films, probably due to their different electron trapping processes. Bandgap excitation in bare WO3 creates deeply trapped electrons in the bulk, whereas the electrons injected from the QDs are trapped at shallow surface states in the remote photochromic system. The successful tailoring of photochromic coloration employing a simple procedure would provide numerous opportunities for designing photo‐ and electrochromic materials with the optimal architecture and tunable properties.
Role of the Charge Transfer State in Organic Donor–Acceptor Solar Cells
Authors: Deibel Carsten , Strobel Thomas , Dyakonov Vladimir
Published: August 2010

Charge transfer complexes are interfacial charge pairs residing at the donor–acceptor heterointerface in organic solar cell. Experimental evidence shows that it is crucial for the photovoltaic performance, as both photocurrent and open circuit voltage directly depend on it. For charge photogeneration, charge transfer complexes represent the intermediate but essential step between exciton dissotiation and charge extraction. Recombination of free charges to the ground state is via the bound charge transfer state before being lost to the ground state. In terms of the open circuit voltage, its maximum achievable value is determined by the energy of the charge transfer state. An important question is whether or not maximum photocurrent and maximum open circuit voltage can be achieved simultaneously. The impact of increasing the CT energy—in order to raise the open circuit voltage, but lowering the kinetic excess energy of the CT complexes at the same time—on the charge photogeneration will accordingly be discussed. Clearly, the fundamental understanding of the processes involving the charge transfer state is essential for an optimisation of the performance of organic solar cells.
Colloidal Self‐Assembly Meets Nanofabrication: From Two‐Dimensional Colloidal Crystals to Nanostructure Arrays
Authors: Zhang Junhu , Li Yunfeng , Zhang Xuemin , Yang Bai
Published: August 2010

Self‐assembly of colloidal microspheres or nanospheres is an effective strategy for fabrication of ordered nanostructures. By combination of colloidal self‐assembly with nanofabrication techniques, two‐dimensional (2D) colloidal crystals have been employed as masks or templates for evaporation, deposition, etching, and imprinting, etc. These methods are defined as “colloidal lithography”, which is now recognized as a facile, inexpensive, and repeatable nanofabrication technique. This paper presents an overview of 2D colloidal crystals and nanostructure arrays fabricated by colloidal lithography. First, different methods for fabricating self‐assembled 2D colloidal crystals and complex 2D colloidal crystal structures are summarized. After that, according to the nanofabrication strategy employed in colloidal lithography, related works are reviewed as colloidal‐crystal‐assisted evaporation, deposition, etching, imprinting, and dewetting, respectively.
Molecular Characterization of Organic Electronic Films
Authors: DeLongchamp Dean M. , Kline R. Joseph , Fischer Daniel A. , Richter Lee J. , Toney Michael F.
Published: August 2010

Organic electronics have emerged as a viable competitor to amorphous silicon for the active layer in low‐cost electronics. The critical performance of organic electronic materials is closely related to their morphology and molecular packing. Unlike their inorganic counterparts, polymers combine complex repeat unit structure and crystalline disorder. This combination prevents any single technique from being able to uniquely solve the packing arrangement of the molecules. Here, a general methodology for combining multiple, complementary techniques that provide accurate unit cell dimensions and molecular orientation is described. The combination of measurements results in a nearly complete picture of the organic film morphology.
Time–temperature–transformation cure diagrams of phenol–formaldehyde and lignin–phenol–formaldehyde novolac resins
Authors: Pérez J. M. , Rodríguez F. , Alonso M. V. , Oliet M.
Published: August 2010

In this study, the time–temperature– transformation (TTT) cure diagrams of the curing processes of several novolac resins were determined. Each diagram corresponded to a mixture of commercial phenol–formaldehyde novolac, lignin–phenol–formaldehyde novolac, and methylolated lignin–phenol–formaldehyde novolac resins with hexamethylenetetramine as a curing agent. Thermomechanical analysis and differential scanning calorimetry techniques were applied to study the resin gelation and the kinetics of the curing process to obtain the isoconversional curves. The temperature at which the material gelled and vitrified [the glass‐transition temperature at the gel point (gelTg)], the glass‐transition temperature of the uncured material (without crosslinking; Tg0), and the glass‐transition temperature with full crosslinking were also obtained. On the basis of the measured of conversion degree at gelation, the approximate glass‐transition temperature/conversion relationship, and the thermokinetic results of the curing process of the resins, TTT cure diagrams of the novolac samples were constructed. The TTT diagrams showed that the lignin–novolac and methylolated lignin–novolac resins presented lower Tg0 and gelTg values than the commercial resin. The TTT diagram is a suitable tool for understanding novolac resin behavior during the isothermal curing process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of a novel histidine‐targeting poly(ethylene glycol) and modification of lysozyme
Authors: Sun Jingjing , Song Xiaoda , Tian Hong , Jin Yuhao , Gao Xiangdong , Yao Wenbing
Published: August 2010

A simple and highly efficient method was developed to prepare a synthetic poly(ethylene glycol) (PEG) derivative, which can be used for conjugation to histidine residue. This derivative reacted with sodium nitrite and the intermediate 4‐diazo‐N‐mPEG‐benzamide proved to have a good performance for histidine modification of lysozyme. Then the pegylated lysozyme was separated and its bacteriolytic activities were determined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Film formation and surface properties of enzymatically crosslinked casein films
Authors: Juvonen Helka , Smolander Maria , Boer Harry , Pere Jaakko , Buchert Johanna , Peltonen Jouko
Published: August 2010

The use of renewable materials as barrier material is currently intensively investigated. Biopolymers such as polysaccharides, lipids, and proteins have been studied as barrier materials. Protein‐based films often possess good gas barrier properties, but because of their hydrophilic nature the gas barrier properties are sensitive to humidity. The improvement of the properties of sodium caseinate barrier films in potential packaging applications was studied by investigating the effects of enzymatic treatment and plasticizer on the film properties. Oxidoreductases Trametes hirsuta laccase (ThL) and Trichoderma reesei tyrosinase (TrTyr) were compared with transglutaminase for crosslinking of the sodium caseinate molecules in the films and coatings. All of the studied enzymes were able to crosslink sodium caseinate. Film solubility tests, protein electrophoresis, contact angle measurements, and atomic force microscopy studies showed that TrTyr treatment results in sodium caseinate films and coatings with better overall properties compared to treatment with ThL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of supercritical CO2 on the interactions between maleated polypropylene and alkyl‐ammonium organoclay
Authors: Liu J. , Thompson M. R. , Balogh M. P. , Speer R. L. , Fasulo P. D. , Rodgers W. R.
Published: August 2010

Supercritical carbon dioxide (scCO2) has been proposed as an effective exfoliating agent for the preparation of polymer‐layered silicate nanocomposites, though there is limited fundamental understanding of this mechanism. This study looks at the interactions of this unique green solvent with three maleated polypropylenes of varying anhydride content and molecular size with an alkyl‐ammonium organoclay. Mixtures of compatibilizers and organoclay were melt‐annealed in a high pressure batch vessel at 200°C and subjected to either a blanket of nitrogen or scCO2 at a pressure of 9.7 MPa. The structures and properties of these melt‐annealed mixtures were characterized by X‐ray diffraction, transmission electron microscopy, Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and contact angle measurement. The results indicate that the plasticizing influence of scCO2 aided intercalation and exfoliation for intercalants of moderate molecular size and anhydride content which would otherwise have limited diffusion into the clay galleries. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improved adhesion of TiO2‐based multilayer coating on HDPE and characterization of photocatalysis
Authors: Kasanen Jussi , Suvanto Mika , Pakkanen Tuula T.
Published: August 2010

Multilayered photocatalytic TiO2‐based coating was prepared by spin coating on a high‐density polyethylene (HDPE) substrate. The multilayered coating consisted of a polyurethane (PU) barrier layer and two layers of TiO2 nanoparticles bound with PU. The adhesion between the HDPE substrate and protective PU coating was enhanced by oxygen plasma treatment of the substrate. The improved adhesion contributed to the photocatalytic degradation of palmitic acid. Long‐term activity of the photocatalytic coating in degradation of palmitic acid under UV illumination was followed by FTIR‐ATR. The catalytic activity of the coating was maintained in three identical cycles where palmitic acid was added and UV‐irradiated for 6 h. According to FTIR measurements, the palmitic acid was almost completely decomposed after 6 h, but gas chromatography (GC) analysis showed total decomposition to require 12 h UV illumination (∼ 97% of palmitic acid decomposed in 12 h). Study of the degradation of palmitic acid by GC as a function of time indicated that the degradation kinetics was pseudofirst order, and the rate constant obtained was 0.31 h−1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A multiprocess eyring model for large strain plastic deformation
Authors: Olley P. , Sweeney J.
Published: August 2010

A multiprocess Eyring model is developed with a particular aim of predicting the localized instability occurring in “necking” polymers when cold‐drawn. Differences from using single and multiple Eyring processes are examined using a published data‐set for polypropylene test pieces; it is shown that a four Eyring process model can simultaneously fit both necking stretch ratio and draw force data for uniaxial stretching, whereas with a single process only one measurement could be fitted accurately. The multi process Eyring model is shown to give significantly more accurate predictions than a necking hyperelastic model. The multiprocess model is assessed against the same material undergoing a complex constant‐width elongation. It is shown that agreement is quantitatively good for both drawing force and surface deformation, with some minor differences in transverse force and surface stretch. A pronounced intermittent stretching pattern that is seen on the experimental test piece is replicated by the multiprocess Eyring simulation, but is absent using the hyperelastic model. A method is described to deform a photograph of the original specimen according to a finite element solution. The method is shown to give a clear indication of the accuracy of the model in predicting final form. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
1,3‐Diaryl‐2‐propenones and 2‐Benzylidene‐1,3‐indandiones: A Quest for Compounds Displaying Greater Toxicity to Neoplasms than Normal Cells
Authors: Pati Hari N. , Das Umashankar , Sakagami Hiroshi , Kawase Masame , Chu Qing , Wang Qintao , Stables James P. , Dimmock Jonathan R.
Published: August 2010

A series of 1,3‐diaryl‐2‐propenones 2a–j and analogous 2‐benzylidene‐1,3‐indandiones 3a–j were evaluated against various neoplasms and normal cells. In general, greater cytotoxic potencies and selective toxicity to human malignant cells were observed by the compounds in series 2 rather than 3. In particular, 2i emerged as a lead molecule having an average CC50 figure of 8.6 µM and a selective index value of 18. Various physicochemical features of 2a–j were correlated with the cytotoxic potencies to neoplastic cell lines which provide guidelines for expansion of this series of compounds. The enone 2i induced internucleosomal DNA fragmentation and activated caspase‐3 in HL‐60 cells suggesting that one of the ways in which the cytotoxicity of the compounds in series 2 is mediated towards some of the cell lines used in this study is by apoptosis. Neurotoxicity in mice was generally lower in series 2 than 3a–j.
Critical Factors in the Seed‐Assisted Synthesis of Zeolite Beta and “Green Beta” from OSDA‐Free Na+–Aluminosilicate Gels
Authors: Kamimura Yoshihiro , Chaikittisilp Watcharop , Itabashi Keiji , Shimojima Atsushi , Okubo Tatsuya
Published: August 2010

Organic structure‐directing agent (OSDA)‐free synthesis of zeolite beta is a subject of both scientific and industrial interest. Herein, we report a comprehensive investigation into the effects of various parameters on the seed‐assisted crystallization of zeolite beta in the absence of OSDA. The crystallization behavior of “OSDA‐free beta” is strongly governed by the chemical composition of the starting Na+‐aluminosilicate gel as well as by the Si/Al ratios of the calcined beta seed crystals, which are prepared using tetraethylammonium hydroxide (TEAOH). Furthermore, OSDA‐free beta seed crystals can be used to form zeolite beta, termed “green beta”. XRD, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and 27Al magic angle spinning NMR analyses showed that the OSDA‐free beta and green beta were of high purity and crystallinity. The nitrogen adsorption–desorption of OSDA‐free beta and green beta revealed higher surface areas and larger volumes in the micropore region than those of the beta seeds synthesized with OSDA after calcination. These results provide a robust and reliable process for the environmentally friendly production of high‐quality zeolite beta in a completely OSDA‐free Na+‐aluminosilicate system.
In vivo Fluorescence Imaging of Tumors using Molecular Aptamers Generated by Cell‐SELEX
Authors: Shi Hui , Tang Zhiwen , Kim Youngmi , Nie Hailong , Huang Yu Fen , He Xiaoxiao , Deng Ke , Wang Kemin , Tan Weihong
Published: August 2010

Poor sensitivity and low specificity of current molecular imaging probes limit their application in clinical settings. To address these challenges, we used a process known as cell‐SELEX to develop unique molecular probes termed aptamers with the high binding affinity, sensitivity, and specificity needed for in vivo molecular imaging inside living animals. Importantly, aptamers can be selected by cell‐SELEX to recognize target cells, or even surface membrane proteins, without requiring prior molecular signature information. As a result, we are able to present the first report of aptamers molecularly engineered with signaling molecules and optimized for the fluorescence imaging of specific tumor cells inside a mouse. Using a Cy5‐labeled aptamer TD05 (Cy5‐TD05) as the probe, the in vivo efficacy of aptamer‐based molecular imaging in Ramos (B‐cell lymphoma) xenograft nude mice was tested. After intravenous injection of Cy5‐TD05 into mice bearing grafted tumors, noninvasive, whole‐body fluorescence imaging then allowed the spatial and temporal distribution to be directly monitored. Our results demonstrate that the aptamers could effectively recognize tumors with high sensitivity and specificity, thus establishing the efficacy of these fluorescent aptamers for diagnostic applications and in vivo studies requiring real‐time molecular imaging.
Lower convex order bound approximations for sums of log‐skew normal random variables
Authors: Roch Oriol , Valdez Emiliano A.
Published: August 2010

When it comes to modeling dependent random variables, not surprisingly, the multivariate normal distribution has received the most attention because of its many appealing properties. However, when it comes to practical implementation, the same family of distribution is often rejected for modeling financial and insurance data because they do not apparently behave in the multivariate normal sense. In this paper, we consider the construction of lower convex order bounds, in the sense of Kaas et al. (Insur. Math. Econ. 2000; 27:151–168), to approximate sums of dependent log‐skew normal random variables. The dependence structure of these random variables is based on the class of multivariate closed skew‐normal (CSN) distribution that appears in González‐Farías et al. (Skew‐Elliptical Distributions and their Applications. A Journey Beyond Normality, Genton MG (ed.), Chapter 6. Chapman & Hall/CRC: Boca Raton, FL, 2004; 25–42) and which carries several interesting properties of the normal distribution apart from allowing additional parameters to regulate skewness. The bounds that we present in this paper are therefore natural extensions to the results presented in Dhaene et al. (Insurance: Mathematics and Economics 2002; 31(2): 133–161; Insurance: Mathematics and Economics 2002b; 31(1):3–33), where bounds for sums of log‐normal random variables have been derived. These lower bound approximations are constructed based on the additional information provided by a conditioning variable which when optimally chosen can provide an accurate approximation. We exploit inherent properties of this family of skew‐normal distributions in order to choose the optimal conditioning variable. Results of our simulations provide an indication of the performance of these approximations. Copyright © 2010 John Wiley & Sons, Ltd.
In vitro study of the effects of ELF electric fields on gene expression in human epidermal cells
Authors: Collard Jean‐Francois , Mertens Benjamin , Hinsenkamp Maurice
Published: August 2010

An acceleration of differentiation, at the expense of proliferation, is observed after exposure of various biological models to low frequency and low amplitude electric and electromagnetic fields. Following these results showing significant modifications, we try to identify the biological mechanism involved at the cell level through microarray screening. For this study, we use epidermis cultures harvested from human abdominoplasty. Two platinum electrodes are used to apply the electric signal. The gene expressions of 38,500 well‐characterized human genes are analyzed using Affymetrix® microarray U133 Plus 2.0 chips. The protocol is repeated on three different patients. After three periods of exposure, a total of 24 chips have been processed. After the application of ELF electric fields, the microarray analysis confirms a modification of the gene expression of epidermis cells. Particularly, four up‐regulated genes (DKK1, TXNRD1, ATF3, and MME) and one down‐regulated gene (MACF1) are involved in the regulation of proliferation and differentiation. Expression of these five genes was also confirmed by real‐time rtPCR in all samples used for microarray analysis. These results corroborate an acceleration of cell differentiation at the expense of cell proliferation. Bioelectromagnetics 32:28–36, 2011. © 2010 Wiley‐Liss, Inc.
ERAD ubiquitin ligases
Authors: Mehnert Martin , Sommer Thomas , Jarosch Ernst
Published: August 2010

In eukaryotic cells terminally misfolded proteins of the secretory pathway are retarded in the endoplasmic reticulum (ER) and subsequently degraded in a ubiquitin‐proteasome‐dependent manner. This highly conserved process termed ER‐associated protein degradation (ERAD) ensures homeostasis in the secretory pathway by disposing faulty polypeptides and preventing their deleterious accumulation and eventual aggregation in the cell. The focus of this paper is the functional description of membrane‐bound ubiquitin ligases, which are involved in all critical steps of ERAD. In the end we want to speculate on how the modular architecture of these entities ensures the specificity of substrate selection and possibly accomplishes the transport of misfolded polypeptides from the ER into the cytoplasm.
The RNA dreamtime
Authors: Kurland Charles G.
Published: August 2010

Modern cells present no signs of a putative prebiotic RNA world. However, RNA coding is not asine qua nonfor the accumulation of catalytic polypeptides. Thus, cellular proteins spontaneously fold into active structures that are resistant to proteolysis. The law of mass action suggests that binding domains are stabilized by specific interactions with their substrates. Random polypeptide synthesis in a prebiotic world has the potential to initially produce only a very small fraction of polypeptides that can fold spontaneously into catalytic domains. However, that fraction can be enriched by proteolytic activities that destroy the unfolded polypeptides and regenerate amino acids that can be recycled into polypeptides. In this open system scenario the stable domains that accumulate and the chemical environment in which they are accumulated are linked through self coding of polypeptide structure. Such open polypeptide systems may have been the precursors to the cellular ribonucleoprotein (RNP) world that evolved subsequently.
Phlorotannins from Ecklonia cava (Phaeophyceae): Biological activities and potential health benefits
Authors: Wijesekara Isuru , Yoon Na Young , Kim Se‐Kwon
Published: August 2010

The importance of bioactive derivatives as functional ingredients has been well recognized due to their valuable health beneficial effects. Therefore, isolation and characterization of novel functional ingredients with biological activities from seaweeds have gained much attention. Ecklonia cava Kjellman is an edible seaweed, which has been recognized as a rich source of bioactive derivatives mainly, phlorotannins. These phlorotannins exhibit various beneficial biological activities such as antioxidant, anticancer, antidiabetic, anti‐human immunodeficiency virus, antihypertensive, matrix metalloproteinase enzyme inhibition, hyaluronidase enzyme inhibition, radioprotective, and antiallergic activities. This review focuses on biological activities of phlorotannins with potential health beneficial applications in functional foods, pharmaceuticals, and cosmeceuticals. © 2010 International Union of Biochemistry and Molecular Biology, Inc.
Puerarin enhances adipocyte differentiation, adiponectin expression, and antioxidant response in 3T3‐L1 cells
Authors: Lee Ok‐Hwan , Seo Dong‐Ho , Park Cheon‐Seok , Kim Young‐Cheul
Published: August 2010

Puerarin, a major isoflavone glycoside from Kudzu root (Pueraria lobata), has been reported to exert antihyperglycemic and antioxidant effects and thus have pharmacological actions in the treatment of diabetes and cardiovascular diseases. We investigated the effects of puerarin on the changes of key gene expression associated with adipocyte differentiation and insulin sensitivity and link to cellular antioxidant response pathways. Puerarin treatment significantly enhanced differentiation of 3T3‐L1 preadipocytes accompanying increased lipid accumulation and glucose‐6‐phosphate dehydrogenase (G6PDH) activity. At a molecular level, puerarin upregulated mRNA expression of peroxisome proliferator‐activated receptor γ (PPARγ) and its target genes, an adipocyte‐specific fatty acid binding protein (aP2) andGLUT4. Puerarin also caused a significant increase in mRNA level of adiponectin, an important insulin‐sensitizing adipocytokine that is downregulated in insulin‐resistant and diabetic states. In addition, treatment with puerarin was found to upregulate mRNA levels ofG6PDH, glutathione reductase, and catalase, all of which are important for endogenous antioxidant responses. These data suggest that the hypoglycemic effects of puerarin can be attributed to the upregulation ofPPARγand its downstream target genes,GLUT4and adiponectin expression, leading to increased glucose utilization. Puerarin may also be effective in preventing the rise of oxidative stress during adipocyte differentiation by increasing endogenous antioxidant responses.
Comparative lipidomic profiling of xylose‐metabolizing S. cerevisiae and its parental strain in different media reveals correlations between membrane lipids and fermentation capacity
Authors: Xia Jinmei , Jones A. Daniel , Lau Ming W. , Yuan Ying‐Jin , Dale Bruce E. , Balan Venkatesh
Published: August 2010

Phospholipids (PLs) serve as the foundation for structure and function in most cell membranes. In order to reveal the correlations between PLs composition and fermentation performance of cells, a comparative lipidomics study was carried out using a recombinant xylose fermenting yeast strain Saccharomyces cerevisiae 424A(LNH‐ST) and its parental strain 4124. Profiling of yeast lipids was performed using ultra performance liquid chromatography (UPLC)‐MS/MS, leading to identification of 123 PL species. PL compositions were determined for both strains grown in rich medium (yeast extract peptone), limited medium (yeast nitrogen base), and ammonia fiber expansion pretreated corn stover hydrolysate. Principal component analysis of lipidomic data revealed that the PL profile for both strains varied significantly depending upon cultivating media composition. Further analysis of different classes of PLs revealed that the phosphatidylinositol/phosphatidylserine (PI/PS) ratio was closely related to cell growth rates. Both strains possessed higher phosphatidylcholine (PC) levels at an expense of phosphatidylethanolamine (PE) levels when entering stationary phase and the PC/PE ratios showed consistency with glucose utilization rates. Interestingly, PI synthesis lagged behind when available nutrients were limited, and PI levels were closely correlated with xylose metabolism. Biotechnol. Bioeng. 2011; 108:12–21. © 2010 Wiley Periodicals, Inc.
Characterization of protein release from hydrolytically degradable poly(ethylene glycol) hydrogels
Authors: Zustiak Silviya P. , Leach Jennie B.
Published: August 2010

We present a novel fully hydrophilic, hydrolytically degradable poly(ethylene glycol) (PEG) hydrogel suitable for soft tissue engineering and delivery of protein drugs. The gels were designed to overcome drawbacks associated with current PEG hydrogels (i.e., reaction mechanisms or degradation products that compromise protein stability): the highly selective and mild cross‐linking reaction allowed for encapsulating proteins prior to gelation without altering their secondary structure as shown by circular dichroism experiments. Further, hydrogel degradation and structure, represented by mesh size, were correlated to protein release. It was determined that polymer density had the most profound effect on protein diffusivity, followed by the polymer molecular weight, and finally by the specific chemical structure of the cross‐linker. By examining the diffusion of several model proteins, we confirmed that the protein diffusivity was dependent on protein size as smaller proteins (e.g., lysozyme) diffused faster than larger proteins (e.g., Ig). Furthermore, we demonstrated that the protein physical state was preserved upon encapsulation and subsequent release from the PEG hydrogels and contained negligible aggregation or protein–polymer adducts. These initial studies indicate that the developed PEG hydrogels are suitable for release of stable proteins in drug delivery and tissue engineering applications. Biotechnol. Bioeng. 2011; 108:197–206. © 2010 Wiley Periodicals, Inc.
Real‐time PCR to study the sequence specific magnetic purification of DNA
Authors: Peeters Sara , Stakenborg Tim , Colle Frederik , Liu ChengXun , Lagae Liesbet , Van Ranst Marc
Published: August 2010

The performance of various molecular techniques using complex biological samples greatly depends on the efficient separation and purification of DNA targets. In recent years, magnetic separation technology making use of small magnetic beads, has gained immense popularity. Most of these methods rely on the non‐specific adsorption of DNA/RNA. However, as presented here, when functionalizing the beads with complementary DNA probes, the target of interest can selectively be isolated. Such sequence specific purification was evaluated for short DNA targets by means of simple fluorescent measurements, resulting in purification efficiencies around 80%. Besides standard fluorescent techniques, a real‐time PCR (qPCR) method was applied for monitoring the purification of longer DNA targets. This qPCR method was specifically optimized for directly quantifying the purification efficiency of low concentrated DNA targets bound to magnetic beads. Additionally, parameters possibly affecting the magnetic isolation, including the length of the used capture probe or the hybridization location, were investigated. Using optimized conditions in combination with qPCR, purification efficiencies between 60% and 80% were observed and this over a large concentration window. These data also show the power of a direct qPCR approach to monitor the magnetic isolation of DNA at very low concentrations. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Anatomic study of the suboccipital artery of Salmon with surgical significance
Authors: D'Antoni Anthony V. , Battaglia Fortunato , Dilandro Anthony C. , Moore Garrett D.
Published: August 2010

The anatomy of the muscular branches of the vertebral arteries has clinical relevance during surgical procedures, suboccipital injections, and manual therapies. Each vertebral artery is divided into four segments. Segment V3, found in the suboccipital triangle, courses posteromedially around the lateral mass to lie in a groove on the posterior arch of the atlas, ultimately coursing beneath the posterior atlanto‐occipital membrane to enter the skull. Although not always present, any muscular branch that emanates from this segment to supply the suboccipital muscles is called the suboccipital artery of Salmon. There is a paucity of literature on this artery despite its clinical relevancy. We found the suboccipital artery of Salmon in 10 (67%) of 15 embalmed adult cadavers. This frequency is considerably higher than that in previous reports. Two (20%) of the 10 cadavers demonstrated bilateral and symmetrical suboccipital arteries of Salmon (one artery on each side). Four (40%) of the 10 cadavers had an arrangement of two parallel suboccipital arteries of Salmon on one side, and one on the contralateral side. Three (30%) of the 10 cadavers displayed an asymmetrical unilateral arrangement (only one artery). One (10%) of the 10 cadavers displayed the unique arrangement of three arteries of Salmon on one side and one artery on the contralateral side. This study adds to a limited, but growing, body of knowledge by providing photographic evidence of the course and arrangement of these arteries and, therefore, can be of value to surgeons and other clinicians whose procedures focus on the suboccipital region. Clin. Anat. 23:798–802, 2010. © 2010 Wiley‐Liss, Inc.
An anatomical ultrasound study of the long posterior sacro‐iliac ligament
Authors: Moore Abigail E. , Jeffery Ruth , Gray Andrew , Stringer Mark D.
Published: August 2010

The long posterior sacro‐iliac ligament (LPSL) is directly posterior to the sacro‐iliac joint and a potential source of lower back and pelvic pain. Its sonographic anatomy has not been described in detail. The aim of this study was to define and measure the ligament in healthy young women using ultrasound (US). The LPSL was scanned in 30 healthy women (median age, 22 years; range, 20–34) using a high‐resolution linear transducer (7.5–10 MHz). The ligament was consistently visualized as a hyperechoic laminated linear structure between the posterior superior iliac spine and the lateral aspect of the third transverse sacral tubercle. Its length, thickness, and the angle between it and the posterior superior iliac spine were measured by an experienced sonographer bilaterally in both semiflexed standing and lateral decubitus positions. Four female cadaver pelves (age range, 57–93 years) were also scanned and dissected to validate US observations. In the semiflexed standing position, mean LPSL length was 37.9 ± 2.4 mm, mean thickness 1.57 ± 0.38mm, and median angle 18.5°. There was no statistically significant difference with equivalent values in the lateral decubitus position. Intrarater repeatability was fair to substantial in both positions (intraclass correlation coefficient, 0.39–0.66), improving to moderate to substantial (intraclass correlation coefficient, 0.57–0.80) using the mean of two measurements. There was good overall agreement between LPSL length and thickness in cadavers measured by US and dissection. These findings document the sonographic appearance, length, and thickness of the LPSL and provide useful normative data for understanding potential LPSL pathology, particularly in relation to pregnancy‐related pelvic girdle pain. Clin. Anat. 23:971–977, 2010. © 2010 Wiley‐Liss, Inc.
Dynamic Calcium Metal–Organic Framework Acts as a Selective Organic Solvent Sponge
Authors: Platero‐Prats Ana E. , de la Peña‐O'Shea Víctor A. , Snejko Natalia , Monge Ángeles , Gutiérrez‐Puebla Enrique
Published: August 2010

Herein, we present a Ca‐based metal–organic framework named AEPF‐1, which is an active and selective catalyst in olefin hydrogenation reactions. AEPF‐1 exhibits a phase transition upon desorption of guest molecules. This structural transformation takes place by a crystal to crystal transformation accompanied by the loss of single‐crystal integrity. Powder diffraction methods and computational studies were applied to determine the structure of the guest‐free phase. This work also presents data on the exceptional adsorption behavior of this material, which is shown to be capable of separating polar from nonpolar organic solvents, and is a good candidate for selective solvent adsorption under mild conditions.
Synthesis and Reactivity of Boron‐, Silicon‐, and Tin‐Bridged ansa‐Cyclopentadienyl–Cycloheptatrienyl Titanium Complexes (Troticenophanes)
Authors: Braunschweig Holger , Fuß Marco , Mohapatra Swagat K. , Kraft Katharina , Kupfer Thomas , Lang Melanie , Radacki Krzysztof , Daniliuc Constantin G. , Jones Peter G. , Tamm Matthias
Published: August 2010

A novel one‐pot method was developed for the preparation of [Ti(η5‐C5H5)(η7‐C7H7)] (troticene, 1) by reaction of sodium cyclopentadienide (NaCp) with [TiCl4(thf)2], followed by reduction of the intermediate [(η5‐C5H5)2TiCl2] with magnesium in the presence of cycloheptatriene (C7H8). The [n]troticenophanes 3 (n=1), 4, 8, 10 (n=2), and 11 (n=3) were synthesized by salt elimination reactions between dilithiated troticene, [Ti(η5‐C5H4Li)(η7‐C7H6Li)]⋅pmdta (2) (pmdta=N,N′,N′,N′′,N′′‐pentamethyldiethylenetriamine), and the appropriate organoelement dichlorides Cl2Sn(Mes)2 (Mes=2,4,6‐trimethylphenyl), Cl2Sn2(tBu)4, Cl2B2(NMe2)2, Cl2Si2Me4, and (ClSiMe2)2CH2, respectively. Their structural characterization was carried out by single‐crystal X‐ray diffraction and multinuclear NMR spectroscopy. The stanna[1]‐ and stanna[2]troticenophanes 3 and 4 represent the first heteroleptic sandwich complexes bearing Sn atoms in the ansa bridge. The reaction of 3 with [Pt(PEt3)3] resulted in regioselective insertion of the [Pt(PEt3)2] fragment into the SnCipso bond between the tin atom and the seven‐membered ring, which afforded the platinastanna[2]troticenophane 5. Oxidative addition was also observed upon treatment of 4 with elemental sulfur or selenium, to produce the [3]troticenophanes [Ti(η5‐C5H4SntBu2)(η7‐C7H6SntBu2)E] (6: E=S; 7: E=Se). The BB bond of the bora[2]troticenophane 8 was readily cleaved by reaction with [Pt(PEt3)3] to form the corresponding oxidative addition product [Ti(η5‐C5H4BNMe2)(η7‐C7H6BNMe2)Pt(PEt3)2] (9). The solid‐state structures of compounds 5, 6, and 9 were also determined by single‐crystal X‐ray diffraction.
ChemInform Abstract: Development of Textured Microstructures in Ceramics with Large Thermal Expansion Anisotropy.
Authors: PAULIK S. W. , FABER K. T. , FULLER E. R. JUN.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Chemical Synthesis and Characterization of Calcium Aluminate Powders.
Authors: GUELGUEN M. A. , POPOOLA O. O. , KRIVEN W. M.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Oxidation Catalysts Produced by Catalytic Oxidation: Preparation, Reactivity and X‐Ray Crystal Structures of (WO(O2)2(pyO)2) and (MoO(O2) 2(pyO)2).
Authors: GRIFFITH W. P. , SLAWIN A. M. Z. , THOMPSON K. M. , WILLIAMS D. J.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Photochemical Generation of the 9‐(Trimethylsilylmethyl)fluoren‐9‐yl Cation. Flash Photolysis Observation of a β‐Silylsubstituted Carbenium Ion
Authors: LEW C. S. Q. , MCCLELLAND R. A. , JOHNSTON L. J. , SCHEPP N. P.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Facile Aerial Oxidation of Porphyrins. Part 16. Phenolic Porphyrins Without tert‐Butyl Substituents.
Authors: MILGROM L. R. , HILL J. P. , FLITTER W. D.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Bromination of 1,2‐Dimethylbenzimidazole with N‐Bromosuccinimide
Authors: KUZ'MINYKH K. S. , DUMPIS M. A.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Phenylacetyl Group as Enzyme‐Cleavable Aminoprotection of Purine Nucleosides.
Authors: DINEVA M. A. , GALUNSKY B. , KASCHE V. , PETKOV D. D.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of 4‐Aryl‐1λ2,2λ4‐dithia‐3,4‐diaza‐buta‐1,2‐ dienes, a New Dithiadiazabutadiene System.
Authors: HESS U. , HOMANN TH. , KOMENDA J.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Stereoelectronic Effects and Chiral Recognition. Part 1. Diastereoselective Formation of Ethers from Alkylarylcarbinols.
Authors: NOE C. R. , KNOLLMUELLER M. , DUNGLER K. , MICULKA C.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.