bluuebunny/crossref_metadata_2025 huggingface dataset:
The TLR9 Ligand CpG Promotes the Acquisition of Plasmodium falciparum-Specific Memory B Cells in Malaria-Naive Individuals
Authors: Crompton Peter D. , Mircetic Marko , Weiss Greta , Baughman Amy , Huang Chiung-Yu , Topham David J. , Treanor John J. , Sanz Iñaki , Lee F. Eun-Hyung , Durbin Anna P. , Miura Kazutoyo , Narum David L. , Ellis Ruth D. , Malkin Elissa , Mullen Gregory E. D. , Miller Louis H. , Martin Laura B. , Pierce Susan K.
Published: February 2009

Despite the central role of memory B cells (MBC) in protective immune responses, little is understood about how they are acquired in naive individuals in response to Ag exposure, and how this process is influenced by concurrent activation of the innate immune system’s TLR. In this longitudinal study of malaria-naive individuals, we examined the MBC response to two candidate malaria vaccines administered with or without CpG, a TLR9 ligand. We show that the acquisition of MBC is a dynamic process in which the vaccine-specific MBC pool rapidly expands and then contracts, and that CpG enhances the kinetics, magnitude, and longevity of this response. We observed that the percentage of vaccine-specific MBC present at the time of reimmunization predicts vaccine-specific Ab levels 14 days later; and that at steady-state, there is a positive correlation between vaccine-specific MBC and Ab levels. An examination of the total circulating MBC and plasma cell pools also suggests that MBC differentiate into plasma cells through polyclonal activation, independent of Ag specificity. These results provide important insights into the human MBC response, which can inform the development of vaccines against malaria and other pathogens that disrupt immunological memory.
NF-κB1 p105 Regulates T Cell Homeostasis and Prevents Chronic Inflammation
Authors: Chang Mikyoung , Lee Andrew J. , Fitzpatrick Leo , Zhang Minying , Sun Shao-Cong
Published: February 2009

Transcription factor NF-κB is regulated by a family of inhibitors, IκBs, as well as the NF-κB1 and NF-κB2 precursor proteins, p105 and p100. Although the different NF-κB inhibitors can all inhibit NF-κB in vitro, their physiological functions are incompletely understood. In this study, we demonstrate that p105 plays an important role in the regulation of T cell homeostasis and prevention of chronic inflammation. Mice lacking p105, but expressing the mature NF-κB1 p50, spontaneously develop intestinal inflammation with features of human inflammatory bowel disease. This inflammatory disorder occurs under specific pathogen-free conditions and critically involves T cells. Consistently, the p105-deficient mice have reduced frequency of naive T cells and increased frequency of memory/effector T cells in the peripheral lymphoid organs. Although p105 is dispensable for the production of immunosuppressive regulatory T cells, p105 deficiency renders CD4 T cells more resistant to Treg-mediated inhibition. We further show that the loss of p105 results in hyperproduction of Th17 subset of inflammatory T cells. Together, these findings suggest a critical role for NF-κB1 p105 in the regulation of T cell homeostasis and differentiation and the control of chronic inflammation.
Reversal of Human Papillomavirus-Specific T Cell Immune Suppression through TLR Agonist Treatment of Langerhans Cells Exposed to Human Papillomavirus Type 16
Authors: Fahey Laura M. , Raff Adam B. , Da Silva Diane M. , Kast W. Martin
Published: February 2009

Human papillomavirus (HPV) type 16 infects the epithelial layer of cervical mucosa and is causally associated with the generation of cervical cancer. Langerhans cells (LC) are the resident APCs at the site of infection and therefore are responsible for initiating an immune response against HPV16. On the contrary, LC exposed to HPV16 do not induce a specific T cell immune response, which leads to the immune evasion of HPV16. Demonstrating that TLR7 and TLR8 are expressed on human LC, we hypothesized that imidazoquinolines would activate LC exposed to HPV16, leading to the induction of an HPV16-specific cell-mediated immune response. Surprisingly, both phenotypic and functional hallmarks of activation are not observed when LC are exposed to HPV16 virus-like particles and treated with imiquimod (TLR7 agonist). However, we found that LC are activated by 3M-002 (TLR8 agonist) and resiquimod (TLR8/7 agonist). LC exposed to HPV16 virus-like particles and subsequently treated with 3M-002 or resiquimod highly up-regulate surface activation markers, secrete proinflammatory cytokines and chemokines, induce CCL21-directed migration, and initiate an HPV16-specific CD8+ T cell response. These data strongly indicate that 3M-002 and resiquimod are promising therapeutics for treatment of HPV infections and HPV-induced cervical lesions.
PD-1/PD-L Blockade Prevents Anergy Induction and Enhances the Anti-Tumor Activities of Glycolipid-Activated Invariant NKT Cells
Authors: Parekh Vrajesh V. , Lalani Saif , Kim Sungjune , Halder Ramesh , Azuma Miyuki , Yagita Hideo , Kumar Vipin , Wu Lan , Van Kaer Luc
Published: February 2009

Invariant NKT (iNKT) cells recognize glycolipid Ags, such as the marine sponge-derived glycosphingolipid α-galactosylceramide (αGalCer) presented by the CD1d protein. In vivo activation of iNKT cells with αGalCer results in robust cytokine production, followed by the acquisition of an anergic phenotype. Here we have investigated mechanisms responsible for the establishment of αGalCer-induced iNKT cell anergy. We found that αGalCer-activated iNKT cells rapidly up-regulated expression of the inhibitory costimulatory receptor programmed death (PD)-1 at their cell surface, and this increased expression was retained for at least one month. Blockade of the interaction between PD-1 and its ligands, PD-L1 and PD-L2, at the time of αGalCer treatment prevented the induction iNKT cell anergy, but was unable to reverse established iNKT cell anergy. Consistently, injection of αGalCer into PD-1-deficient mice failed to induce iNKT cell anergy. However, blockade of the PD-1/PD-L pathway failed to prevent bacterial- or sulfatide-induced iNKT cell anergy, suggesting additional mechanisms of iNKT cell tolerance. Finally, we showed that blockade of PD-1/PD-L interactions enhanced the antimetastatic activities of αGalCer. Collectively, our findings reveal a critical role for the PD-1/PD-L costimulatory pathway in the αGalCer-mediated induction of iNKT cell anergy that can be targeted for the development of immunotherapies.
Role of Tim-3/Galectin-9 Inhibitory Interaction in Viral-Induced Immunopathology: Shifting the Balance toward Regulators
Authors: Sehrawat Sharvan , Suryawanshi Amol , Hirashima Mitsuomi , Rouse Barry T.
Published: February 2009

Controlling chronic immunoinflammatory diseases such as lesions in the eye caused by infection with HSV represents a therapeutic challenge. Since CD4+ T cells are the primary orchestrators of lesions, targeting activated CD4+ T cell subsets and increasing the representation of cells that express regulatory function would be a logical therapeutic approach. We show that this outcome can be achieved by therapy, systemic or local, with the lectin family member galectin-9. This molecule, which is a natural product of many cell types, acts as a ligand to the inhibitory molecule TIM-3 (T cell Ig and mucin-3) that is expressed by activated but not naive T cells. We show that 50% or more of T cells in ocular lesions caused by HSV in mice express TIM-3 and that blocking signals from its natural ligand with a mAb results in more severe lesions. More importantly, the provision of additional galectin-9, either systemically or more effectively by local subconjuctival administration, diminished the severity of stromal keratitis lesions as well as the extent of corneal neovascularization. Multiple mechanisms were involved in inhibitory effects. These included apoptosis of the orchestrating effector T cells with consequent reduction of proinflammatory cytokines and an increase in the representation of two separate subtypes of regulatory cells as well as inhibitory effects on the production of molecules involved in neovascularization, an essential component of stromal keratitis pathogenesis. Our results indicate that galectin-9 therapy may represent a useful approach to control HSV-induced lesions, the most common cause of infectious blindness in the Western world.
The Glucocorticoid-Induced TNF Receptor-Related Protein (GITR)-GITR Ligand Pathway Acts As a Mediator of Cutaneous Dendritic Cell Migration and Promotes T Cell-Mediated Acquired Immunity
Authors: Kamimura Yosuke , Iwai Hideyuki , Piao Jinhua , Hashiguchi Masaaki , Azuma Miyuki
Published: February 2009

Glucocorticoid-induced TNFR-related protein (GITR) has various roles in the activation of T cells and inflammation. In this study, we investigated the roles of the GITR-GITR ligand (GITRL) pathway in contact hypersensitivity (CH). Treatment with anti-GITRL mAb at sensitization inhibited CH responses. Depletion studies using an anti-CD25 or anti-PDCA-1 mAb revealed that regulatory T cells and plasmacytoid dendritic cells (DCs), known to express high levels of GITR and GITRL, respectively, were not apparently involved in GITRL-mediated CH responses. Treatment with/addition of anti-GITRL mAb in the experiments for hapten-specific T cell proliferation and IFN-γ production showed a minor contribution of the GITRL, which was weakly expressed on DCs in draining lymph nodes (dLNs). Interestingly, anti-GITRL mAb treatment inhibited the migration of cutaneous DCs to the dLNs. Epidermal keratinocytes (KCs) constitutively express GITR, whereas Langerhans cells (LCs) express higher levels of GITRL compared with DCs in dLNs. GITR ligation, by an anti-GITR mAb, in KCs promoted expression of multiple proinflammatory cytokines and blockade of GITRL-inhibited IL-1β and CCR7 expression in sensitized skin. These results suggest that the GITR-GITRL pathway promotes epidermal inflammatory cytokine production by KCs and LCs, resulting in migration of cutaneous DCs from the skin to the dLNs. This is the first report demonstrating the involvement of the GITR-GTRL pathway in interactions with KCs and LCs and the migration of DCs. Our findings provide important implications for understanding the molecular bases of KC-LC interactions and for developing new therapeutic strategies in skin disease.
Cutting Edge: Mucosal Application of a Lyophilized Viral Vector Vaccine Confers Systemic and Protective Immunity toward Intracellular Pathogens
Authors: Kastenmuller Wolfgang , Gasteiger Georg , Stross Leon , Busch Dirk H. , Drexler Ingo
Published: February 2009

A major problem of current vaccines is storage stability, often requiring strict maintenance of cold chains. In the course of the eradication of smallpox, a freeze-dried vaccinia virus (Dryvax), which proved to be very stable, was used to overcome this limitation. However, Dryvax needs to be reconstituted before usage and is administered using a bifurcated needle, procedures that pose a number of additional health risks. We report in this study that a stable, lyophilized, modified vaccinia virus Ankara (MVA) vaccine can be directly applied to the nostrils of mice without previous reconstitution. This direct mucosal application induced systemic Ab and T cell responses comparable to those achieved by i.m. administration. Importantly, mucosal application of lyophilized MVA induced long-lasting protective immunity against lethal bacterial and viral challenges. These data clearly demonstrate the potency of a simple needle-free vaccination, combining the advantages of mucosal application with the stability and efficiency of lyophilized MVA.
Cutting Edge: In Vitro Generated Th17 Cells Maintain Their Cytokine Expression Program in Normal but Not Lymphopenic Hosts
Authors: Nurieva Roza , Yang Xuexian O. , Chung Yeonseok , Dong Chen
Published: February 2009

Upon activation, naive CD4+ T cells differentiate into effector Th cell subsets. The stability and plasticity of effector Th cells have not been well understood. In this study we used an IL-17F-red fluorescent protein reporter mouse to analyze the plasticity of Th17 cells in vitro and in vivo. We found that in vitro generated Th17 cells poorly maintained their differentiation program in vitro and could be reprogrammed into other T cell lineages. Moreover, upon transfer into lymphopenic hosts, Th17 cells rapidly lost their IL-17 expression and were converted into Th1 cells independently of IL-7 signaling. However, Th17 cells maintained their phenotypes well in normal animals, even in the absence of Ag and inflammation. These results, although suggesting the plasticity of Th17 cells, also indicate active maintenance of their program in vivo.
Cutting Edge: Killer Ig-Like Receptors Mediate “Missing Self” Recognition In Vivo
Authors: van Bergen Jeroen , Thompson Allan , Retière Christelle , Trowsdale John , Koning Frits
Published: February 2009

Although it is well established that human NK cells are able to detect the absence of autologous HLA class I in vitro by virtue of inhibitory killer Ig-like receptors (KIR), direct evidence that KIR can mediate “missing self” recognition in vivo is lacking. To test this, we generated mice transgenic for a human KIR B-haplotype and HLA-Cw3 on a C57BL/6 background. NK cells in these mice expressed multiple KIR in a stochastic manner, including the HLA-Cw3-specific inhibitory receptor KIR2DL2. KIR and HLA transgenic mice rejected wild-type C57BL/6 spleen cells upon i.v. injection. This rejection was dependent on the presence of the KIR transgene in the host and on the absence of HLA-Cw3 from the injected target cells. Hence, the KIR transgene mediated “missing self” recognition in vivo. We anticipate that this KIR and HLA transgenic mouse will help shed light on KIR and HLA effects in disease and transplantation.
A Sense of ‘unrealness’ about the death of a loved‐one: An exploratory study of its role in emotional complications among bereaved individuals
Authors: Boelen Paul A.
Published: February 2009

After a loss, some people develop complicated grief (CG) and depression. A recent cognitive‐behavioural model postulates that three processes account for such problems: (a) lack of integration of the loss with implicit autobiographical knowledge about the relationship with the lost person, (b) negative cognitions and (c) avoidance behaviours. In the current study, it was proposed that the ‘lack of integration of the loss’ is mainly an implicit process, but has an explicit, introspectively accessible counterpart in the form of ‘a sense of unrealness’ that can be defined as a subjective sense of uncertainty or ambivalence about the irreversibility of the separation. The role of this ‘sense of unrealness’ was studied using self‐reported data from 397 mourners. Among other things, findings showed that items constituting unrealness were distinct from those of CG and depression. In addition, unrealness was significantly associated with CG, when controlling for negative cognitions, avoidance and concomitant depression. Copyright © 2009 John Wiley & Sons, Ltd.
Capacity Fading Mechanism in All Solid‐State Lithium Polymer Secondary Batteries Using PEG‐Borate/Aluminate Ester as Plasticizer for Polymer Electrolytes
Authors: Kaneko Fuminari , Wada Shinta , Nakayama Masanobu , Wakihara Masataka , Koki Jun , Kuroki Shigeki
Published: February 2009

Solid‐state lithium polymer secondary batteries (LPB) are fabricated with a two‐electrode‐type cell construction of Li|solid‐state polymer electrolyte (SPE)|LiFePO4. Plasticizers of poly(ethylene glycol) (PEG)‐borate ester (B‐PEG) or PEG‐aluminate ester (Al‐PEG) are added into lithium‐conducting SPEs in order to enhance their ionic conductivity, and lithium bis‐trifluoromethansulfonimide (LiTFSI) is used as the lithium salt. An improvement of the electrochemical properties is observed upon addition of the plasticizers at an operation temperature of 60 °C. However, a decrease of discharge capacities abruptly follows after tens of stable cycles. To understand the origin of the capacity fading, electrochemical impedance techniques, ex‐situ NMR and scanning electron microscopy (SEM)/energy dispersive X‐ray spectroscopy (EDS) techniques are adopted. Alternating current (AC) impedance measurements indicate that the decrease of capacity retention in the LPB is related to a severe increase of the interfacial resistance between the SPE and cathode. In addition, the bulk resistance of the SPE film is observed to accompany the capacity decay. Ex situ NMR studies combined with AC impedance measurements reveal a decrease of Li salt concentration in the SPE film after cycling. Ex situ SEM/EDS observations show an increase of concentration of anions on the electrode surface after cycling. Accordingly, the anions may decompose on the cathode surface, which leads to a reduction of the cycle life of the LPB. The present study suggests that a choice of Li salt and an increase of transference number is crucial for the realization of lithium polymer batteries.
Tuning Carbon Materials for Supercapacitors by Direct Pyrolysis of Seaweeds
Authors: Raymundo‐Piñero Encarnación , Cadek Martin , Béguin François
Published: February 2009

The sea provides a large variety of seaweeds that, because of their chemical composition, are fantastic precursors of nanotextured carbons. The carbons are obtained by the simple pyrolysis of the seaweeds under a nitrogen atmosphere between 600 and 900 °C, followed by rinsing the product in slightly acidic water. Depending on the origin of the seaweed and on the pyrolysis conditions, the synthesis may be oriented to give an oxygen‐enriched carbon or to give a tuned micro/mesoporous carbon. The samples with a rich oxygenated surface functionality are excellent as supercapacitor electrodes in an aqueous medium whereas the perfectly tuned porous carbons are directly applicable for organic media. In both cases, the specific surface area of the attained carbons does not exceed 1300 m2 g−1, which results in high‐density materials. As a consequence, the volumetric capacitance is very high, making these materials more interesting than activated carbons from the point of view of developing small and compact electric power sources. Such versatile carbons, obtained by a simple, ecological, and cheap process, could be well used for environment remediation such as water and air treatment.
Long‐Cycle Electrochemical Behavior of Multiwall Carbon Nanotubes Synthesized on Stainless Steel in Li Ion Batteries
Authors: Masarapu Charan , Subramanian Venkatachalam , Zhu Hongwei , Wei Bingqing
Published: February 2009

Carbon nanotubes (CNTs) are considered to be excellent candidates for high performance electrode materials in Li ion batteries. The nanometer‐sized pore structures of CNTs can provide the hosting sites for storing large numbers of Li ions. A short diffusion distance for the Li ions may bring about a high discharge rate. The long‐cycle performance of aligned multiwalled carbon nanotubes (MWNTs) directly synthesized on stainless‐steel foil as an anode material in lithium battery is demonstrated. An increase in the specific capacity with an increase in the cycle number is observed. Starting at a value of 132 mA hg−1 in the first cycle at a current rate of 1 C, the specific capacity increased about 250% to a value of 460 mA hg−1 after 1 200 cycles. This is an unusual but a welcoming behavior for battery applications. It is found that the morphology of the MWNTs with structural and surface defects and the stainless‐steel substrate play an important role in enhancing the capacity during the cycling process.
Nanocoating hybrid polymer films on large quantities of cohesive nanoparticles by molecular layer deposition
Authors: Liang Xinhua , King David M. , Li Peng , George Steven M. , Weimer Alan W.
Published: February 2009

The conformal coating of ultra‐thin aluminum alkoxide (alucone) polymer films on primary silica and titania nanoparticles using molecular layer deposition (MLD) in a fluidized bed reactor from 100 to 160 °C is described. In situ mass spectrometry revealed that the growth of alucone MLD films was self‐limiting as a function of the individual trimethylaluminum and ethylene glycol exposures. The composition and highly conformal alucone films throughout the surface of both silica and titania nanoparticles were confirmed. The highest growth rate was observed at the lowest sample temperature. Primary nanoparticles were coated individually despite their strong tendency to aggregate during fluidization. Based on the results of chemical and thermogravimetric analysis, the value of x in the formula of Al(OCH2CH2O)x was estimated to be 1.9. The calculated film density slightly increased from 2.0 ± 0.1 to 2.2 ± 0.1 g/cm3 with the increasing of temperature from 100 to 160 °C. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Race and global patterns of phenotypic variation
Authors: Relethford John H.
Published: February 2009

Phenotypic traits have been used for centuries for the purpose of racial classification. Developments in quantitative population genetics have allowed global comparison of patterns of phenotypic variation with patterns of variation in classical genetic markers and DNA markers. Human skin color shows a high degree of variation among geographic regions, typical of traits that show extensive natural selection. Even given this high level of geographic differentiation, skin color variation is clinal and is not well described by discrete racial categories. Craniometric traits show a level of among‐region differentiation comparable to genetic markers, with high levels of variation within populations as well as a correlation between phenotypic and geographic distance. Craniometric variation is geographically structured, allowing high levels of classification accuracy when comparing crania from different parts of the world. Nonetheless, the boundaries in global variation are not abrupt and do not fit a strict view of the race concept; the number of races and the cutoffs used to define them are arbitrary. The race concept is at best a crude first‐order approximation to the geographically structured phenotypic variation in the human species. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
1918: Three perspectives on race and human variation
Authors: Caspari Rachel
Published: February 2009

Race was an important topic to the physical anthropologists of 1918, but their views were not monolithic. Multiple perspectives on race are expressed in the first volume of the AJPA, which encompass biological determinism and assumptions about evolutionary processes underlying the race concept. Most importantly, many of the significant alternative approaches to the study of human variation were already expressed in 1918. This paper examines race from the different perspectives of three key contributions to the first volume of the AJPA: papers from Hrdlička, Hooton, and Boas. The meaning of race derived from this work is then discussed. Despite new understandings gained through the neo‐Darwinian synthesis and the growth of genetics, the fundamentals of the modern discussions of race were already planted in 1918. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Human DNA sequences: More variation and less race
Authors: Long Jeffrey C. , Li Jie , Healy Meghan E.
Published: February 2009

Interest in genetic diversity within and between human populations as a way to answer questions about race has intensified in light of recent advances in genome technology. The purpose of this article is to apply a method of generalized hierarchical modeling to two DNA data sets. The first data set consists of a small sample of individuals (n = 32 total, from eight populations) who have been fully resequenced for 63 loci that encode a total of 38,534 base pairs. The second data set consists of a large sample of individuals (n = 928 total, from 46 populations) who have been genotyped at 580 loci that encode short tandem repeats. The results are clear and somewhat surprising. We see that populations differ in the amount of diversity that they harbor. The pattern of DNA diversity is one of nested subsets, such that the diversity in non‐Sub‐Saharan African populations is essentially a subset of the diversity found in Sub‐Saharan African populations. The actual pattern of DNA diversity creates some unsettling problems for using race as meaningful genetic categories. For example, the pattern of DNA diversity implies that some populations belong to more than one race (e.g., Europeans), whereas other populations do not belong to any race at all (e.g., Sub‐Saharan Africans). As Frank Livingstone noted long ago, the Linnean classification system cannot accommodate this pattern because within the system a population cannot belong to more than one named group within a taxonomic level. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.
Biomineralization Nanolithography: Combination of Bottom‐Up and Top‐Down Fabrication To Grow Arrays of Monodisperse Gold Nanoparticles Along Peptide Lines
Authors: Nuraje Nurxat , Mohammed Samia , Yang Linglu , Matsui Hiroshi
Published: February 2009

Von oben und von unten: Schneisen in selbstorganisierten Monoschichten (SAM) auf einem Goldsubstrat wurden mit Peptidlinien gefüllt. Eine Kombination von Top‐down‐ (Peptidnanolithographie) und Bottom‐up‐Verfahren (Biomineralisation) ermöglichte es, monodisperse Goldnanopartikel auf diesen Peptidlinien abzuscheiden (siehe Bild). Die Zahl an Nanopartikeln auf den Linien war durch die Breite des Peptidmusters bestimmt.

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Total Synthesis of (−)‐Amphidinolide K
Authors: Ko Haye Min , Lee Chung Whan , Kwon Hyung Kyoo , Chung Hea Seung , Choi Soo Young , Chung Young Keun , Lee Eun
Published: February 2009

Macrolide magic: An enyne cross‐metathesis reaction of an alkynyl boronate with an alkene derivative as well as a radical cyclization reaction of a homopropargylic β‐alkoxyacrylate are the key transformations in the total synthesis of the cytotoxic macrolide (−)‐amphidinolide K.

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Pd‐PEPPSI‐IPent: An Active, Sterically Demanding Cross‐Coupling Catalyst and Its Application in the Synthesis of Tetra‐Ortho‐Substituted Biaryls
Authors: Organ Michael G. , Çalimsiz Selçuk , Sayah Mahmoud , Hoi Ka Hou , Lough Alan J.
Published: February 2009

Incredible Bulk: A series of N‐heterocyclic carbene catalysts (see picture) were prepared and evaluated in the Suzuki–Miyaura reaction. A variety of sterically encumbered tetra‐ortho‐substituted biaryl products were formed from unreactive aryl chlorides using the isopentyl‐substituted catalyst at temperatures ranging from 65 °C to room temperature. The cyclopentyl‐substituted catalyst was virtually inactive, demonstrating that “flexible bulk” is essential to promote these transformations.

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The variation of the dielectric constant and loss index with temperature and draw ratio in α‐PVDF
Authors: Ozkazanc E. , Guney H. Y.
Published: February 2009

In this study, the effect of measurement temperature and uniaxial drawing on the real (dielectric constant, ε′) and imaginary (loss index, ε″) parts of the complex dielectric constant of α‐crystalline phase poly(vinylidene fluoride) (PVDF) was investigated. The samples having different draw ratios (λ) were obtained by drawing the PVDF film at constant speed and temperature. The dielectric measurements were performed in the frequency range of 100 Hz–1 MHz and in the temperature range of 80–400 K. Although ε′ and ε″ were not affected by the orientation process during the β‐relaxation transition, it was observed that there were systematical variations for the α‐relaxation transition. ε′ and ε″ showed different behaviors depending on the draw ratio at different temperatures. Especially, ε″ was more affected by the orientation process at 380 K. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of hyperbranched cationic polyelectrolytes via aqueous self‐condensing atom transfer radical polymerization
Authors: Gao Jun , Zhai Guangqun , Song Yan , Jiang Bibiao
Published: February 2009

The hyperbranched cationic polyelectrolytes (PDMEAB) were directly prepared via the CuBr/ligand‐catalyzed (ligand = 2,2′‐bipyridine or pentamethyldiethylenetriamine) aqueous self‐condensing atom transfer radical polymerization (SCATRP) of a novel inimer, N,N‐dimethyl‐N‐(2‐methacryloyloxy)ethyl‐N‐(2‐bromoisobutyryloxy)ethyl ammonium bromide (DMEAB). Elemental analysis and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of DMEAB. The hyperbranched architecture and number‐average degree of polymerization (DPn) of the PDMEAB was studied by 1H‐ and 13C‐NMR. The kinetic results suggested that the DPn of the hyperbranched PDMEAB grew gradually in the initial stage and exponentially in the later stage. The differential scanning calorimetry (DSC) showed that the glass transition temperature of the hyperbranched PDMEAB was much lower than that of the linear analogue. The solution rheometry showed that the aqueous PDMEAB solutions approximately underwent a Newtonian behavior and their shear viscosity maintained almost constant upon the addition of NaCl because of the spherical conformations of the hyperbranched cationic polyelectrolytes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of antimicrobial silver nanoparticles on silk fibers via γ‐radiation
Authors: Chang Shuquan , Kang Bin , Dai Yaodong , Chen Da
Published: February 2009

Antimicrobial silver nanoparticles (NPs) were successfully synthesized on the surface of silk fibers via γ‐ray irradiation. The products were characterized with scanning electron microscope (SEM), energy dispersion spectrum, and X‐ray diffraction. The results revealed that the silver particles with a diameter of less than 20 nm were immobilized and well dispersed on the surface of silk fibers. The antimicrobial capability against the gram positive bacterium Staphylococcus aureus and the washing stability of the silk fibers produced with different conditions were tested and found to be excellent. The silk fibers treated with 1 mM solution and 10 kGy γ‐radiation showed 96% antimicrobial activity and still kept above 85% antibacterial activity after 10 washing cycles. Moreover, a mechanism for the formation of silver NPs on silk fibers under γ‐radiation was generally discussed. The resulting silk fibers coated with silver NPs can be useful as functional fabrics in a range of applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Pervaporation performance of polydimethylsiloxane membranes for separation of benzene/cyclohexane mixtures
Authors: Chen Jian , Li Jiding , Lin Yangzheng , Chen Cuixian
Published: February 2009

Crosslinked polydimethylsiloxane/polyetherimide (PDMS/PEI) composite membranes were prepared, in which asymmetric microporous PEI membrane prepared with phase inversion method was acted as the microporous supporting layer in the flat‐plate composite membrane. The different function composition of the PDMS/PEI composite membranes were characterized by reflection Fourier transform infrared (FTIR) spectroscopy. The surface and section of PDMS/PEI composite membranes were investigated by scanning electron microscope (SEM). The composite membranes prepared in this work were employed in pervaporation separation of benzene/cyclohexane mixtures. Effects of feed temperature, feed composition, concentration of crosslinking agent on the separation efficiency of benzene/cyclohexane mixtures were investigated experimentally. In addition, the swelling rate and stableness of composite membrane during long time operation were studied, which should be significant for practical application. The results demonstrated that the pervaporation method could be very effective for separation of the benzene/cyclohexane mixtures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Drug diffusion in neutral and ionic hydrogels assembled from acetylated galactoglucomannan
Authors: Voepel Jens , Sjöberg John , Reif Michael , Albertsson Ann‐Christine , Hultin Ulla‐Karin , Gasslander Ulla
Published: February 2009

In this study, hydrogels based on acetylated galactoglucomannan (AcGGM)—a hemicellulose present in softwood—were synthesized and examined for their properties in drug‐release systems using two model substances of different molecular weight, size, and polarity (caffeine and vitasyn blue). Neutral hydrogels were produced from functionalized AcGGM using hydroxyethyl methacrylate (HEMA) coupled via carbonyldiimidazole (CDI) and a co‐monomer in a radical‐initiated polymerization. Through a second modification reaction between the HEMA‐modified AcGGM (M‐AcGGM‐methacrylated AcGGM) and maleic anhydride, a “double‐modified” AcGGM (CM‐AcGGM‐carboxylated M‐AcGGM) was successfully formed that could be cross‐linked to form ionic hydrogels by the very same polymerization method. The neutral hydrogels showed drug release kinetics that could be easily regulated by changing the relative amount of the methacrylated AcGGM and its corresponding degree of methacrylation. The drug release rate and the Fickian swelling decreased with an increase in these two aforementioned parameters. The ionic hydrogels showed quicker release kinetics and higher swelling capabilities than the corresponding nonionic gels did, especially at neutral conditions. Under acidic conditions, the release speed was lowered as expected because of protonation of carboxylic functionalities. Based on the findings we conclude that these novel hemicellulose‐containing hydrogels have future prospects in drug release formulations, e.g., in a later stage of development for application in oral drug administration technology. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane foams from soyoil‐based polyols
Authors: Campanella A. , Bonnaillie L. M. , Wool R. P.
Published: February 2009

The focus of this work was to synthesize bio‐based polyurethane (PU) foams from soybean oil (SO). Different polyols from SO were produced as follows: soybean oil monoglyceride (SOMG), hydroxylated soybean oil (HSO), and soybean oil methanol polyol (SOMP). The SOMG was a mixture of 90.1% of monoglyceride, 1.3% of diglyceride, and 8.6% of glycerol. The effect of various variables (polyol reactivity, water content curing temperature, type of catalyst, isocyanate, and surfactant) on the foam structure and properties were analyzed. SOMG had the highest reactivity because it was the only polyol‐containing primary hydroxyl (OH) groups in addition to a secondary OH group. PU foams made with SOMG and synthetic polyol contained small uniform cells, whereas the other SO polyols produced foams with a mixture of larger and less uniform cells. The type of isocyanate also had an influence on the morphology, especially on the type of cells produced. The foam structure was found to be affected by the water and catalyst content, which controlled the foam density and the cure rate of the PU polymer. We observed that the glass transition (Tg) increased with the OH value and the type of diisocyanate. Also, we found that the degree of solvent swelling (DS) decreased as Tg increased with crosslink density. These results are consistent with the Twinkling Fractal Theory of Tg. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characteristic Morphology and Distribution of Bone Marrow Derived Cells in the Cornea
Authors: Takayama Tetsuya , Kondo Teruyoshi , Kobayashi Masatoshi , Ohta Keisuke , Ishibashi Yoshihiro , Kanemaru Takaaki , Shimazu Hideki , Ishikawa Fumihiko , Nakamura Takahiro , Kinoshita Shigeru , Nakamura Kei‐Ichiro
Published: February 2009

Enhanced green fluorescence protein (eGFP)‐labeled bone marrow (BM) cells were transplanted into syngeneic C57BL/6 (wild‐type) mice to investigate the distribution pattern, immunohistochemical characteristics, three‐dimensional structure, and ultrastructure of the BM‐derived cells in the mouse cornea using a fluorescence microscope, a confocal laser scanning microscope, and a transmission electron microscope. This study provided direct evidence that two morphologically distinct types of BM‐derived cells were distributed in the mouse cornea. The majority of the GFP(+) cells showed a flattened polygonal form with obtuse angles and these cells were distributed in the corneal stroma. The other type was the GFP(+) cells demonstrating slim cell bodies with long and extremely thin dendrites and which were distributed in the corneal epithelium. The immunohistochemical characteristics and ultrastructure of BM‐derived cells suggest that most of these cells have a macrophage lineage, whereas some cells in the corneal stroma do not. Interestingly, the direct intimate contact between GFP‐labeled BM derived cells and non‐GFP‐labeled resident cells within the corneal stroma were also clearly visualized at the fine structural level. These data provide new and more detailed insight into the nature of BM‐derived cells in the cornea. Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Libcitations: A measure for comparative assessment of book publications in the humanities and social sciences
Authors: White Howard D. , Boell Sebastian K. , Yu Hairong , Davis Mari , Wilson Concepción S. , Cole Fletcher T.H.
Published: February 2009

Bibliometric measures for evaluating research units in the book‐oriented humanities and social sciences are underdeveloped relative to those available for journal‐oriented science and technology. We therefore present a new measure designed for book‐oriented fields: the “libcitation count.” This is a count of the libraries holding a given book, as reported in a national or international union catalog. As librarians decide what to acquire for the audiences they serve, they jointly constitute an instrument for gauging the cultural impact of books. Their decisions are informed by knowledge not only of audiences but also of the book world (e.g., the reputations of authors and the prestige of publishers). From libcitation counts, measures can be derived for comparing research units. Here, we imagine a match‐up between the departments of history, philosophy, and political science at the University of New South Wales and the University of Sydney in Australia. We chose the 12 books from each department that had the highest libcitation counts in the Libraries Australia union catalog during 2000 to 2006. We present each book's raw libcitation count, its rank within its Library of Congress (LC) class, and its LC‐class normalized libcitation score. The latter is patterned on the item‐oriented field normalized citation score used in evaluative bibliometrics. Summary statistics based on these measures allow the departments to be compared for cultural impact. Our work has implications for programs such as Excellence in Research for Australia and the Research Assessment Exercise in the United Kingdom. It also has implications for data mining in OCLC's WorldCat.
Light Harvesting and Efficient Energy Transfer in Dendritic Systems: New Strategy for Functionalized Near‐Infrared BF2‐Azadipyrromethenes
Authors: Yuan Mingjian , Yin Xiaodong , Zheng Haiyan , Ouyang Canbin , Zuo Zicheng , Liu Huibiao , Li Yuliang
Published: February 2009

Bright funnels: A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of dendrimers have been determined. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for the modification of near‐infrared BF2‐Azadipyrromethenes.

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A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of the dendrimers, generations 0–2, have been determined. The light‐harvesting ability of these compounds increases with increasing generation arising from the increase in molar extinction coefficient. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for modification of near‐infrared BF2‐Azadipyrromethene.
Unusual Side‐Chain Effects on Charge‐Carrier Lifetime in Discotic Liquid Crystals
Authors: Motoyanagi Jin , Yamamoto Yohei , Saeki Akinori , Alam Md. Akhtarul , Kimoto Atsushi , Kosaka Atsuko , Fukushima Takanori , Seki Shu , Tagawa Seiichi , Aida Takuzo
Published: February 2009

Long live the carrier! Hexa‐peri‐hexabenzocoronene derivatives, carrying paraffinic side chains terminated with ester–ether groups, form hexagonal columnar assemblies over a wide temperature range including room temperature. Within this temperature range, the lifetimes of charge carriers generated by laser flash photolysis are observed to be extremely long (14–40 ms).

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When hexa‐peri‐hexabenzocoronene (HBC) carries paraffinic side chains with ester–ether termini (1 a–1 c), a hexagonal columnar liquid‐crystalline (LC) mesophase forms, which is characterized by a very wide temperature range (ca. 0–300 °C). The LC materials from these HBC derivatives show characteristic electronic properties with an extremely long photocarrier lifetime. For example, by means of a flash‐photolysis time‐resolved microwave conductivity technique, the photocarrier lifetime, observed for liquid‐crystalline 1 a, is as long as 14 ms, which is four‐orders of magnitude longer than that of fully paraffinic HBC 4 (0.0011 ms). The maximum transient photoconductivities of liquid‐crystalline 1 a–1 c are comparable to one another and also to those of HBCs without ester–ether terminals. Liquid‐crystalline 1 a exhibits an obvious photocurrent generation in response to light illumination.
Growth inhibition of Staphylococcus aureus induced by low‐frequency electric and electromagnetic fields
Authors: Obermeier Andreas , Matl Florian Dominik , Friess Wolfgang , Stemberger Axel
Published: February 2009

Magnetic field therapy is an established technique in the treatment of pseudarthrosis. In cases of osteomylitis, palliation is also observed. This study focuses on the impact of different electric and electromagnetic fields on the growth of Staphylococcus aureus by in vitro technologies. Cultures of Staphylococcus aureus in fluid and gel‐like medium were exposed to a low‐frequency electromagnetic field, an electromagnetic field combined with an additional electric field, a sinusoidal electric field and a static electric field. In gel‐like medium no significant difference between colony‐forming units of exposed samples and non‐exposed references was detected. In contrast, Staphylococcus aureus concentrations in fluid medium could clearly be reduced under the influence of the four different applied fields within 24 h of experiment. The strongest effects were observed for the direct current electric field which could decrease CFU/ml of 37%, and the low‐frequency electromagnetic field with additional induced electric alternating field with a decrease of Staphylococci concentration by 36%. The effects of the electromagnetic treatment on Staphylococci within fluid medium are significantly higher than in gel‐like medium. The application of low‐frequency electromagnetic fields corroborates clinical situations of bone infections during magnetic field therapy. Bioelectromagnetics 30:270–279, 2009. © 2009 Wiley‐Liss, Inc.
Piezoelectric inkjet printing of a cross‐hatch immunoassay on a disposable nylon membrane
Authors: Stewart Thomas N. , Pierson Bonnie E. , Aggarwal Ravi , Narayan Roger J.
Published: February 2009

The development of a cost‐effective method for manufacturing immunoassays is a key step towards their commercial use. In this study, a piezoelectric inkjet printer and a nylon membrane were used to fabricate a disposable immunoassay. Using a piezoelectric inkjet printer, a cross‐hatch pattern of goat anti‐mouse antibody (GαM) and rabbit anti‐horseradish peroxidase (RαHRP) antibody were deposited on the nylon membrane. These patterns were subsequently treated with a solution containing rabbit anti‐goat antibody labeled with horseradish peroxidase (RαG‐HRP). The effectiveness of the immobilization process was examined using tetramethylbenzidine (TMB), which oxidizes in the presence of HRP to form a visible precipitate. Optical evaluation of the TMB precipitate was used to assess the precision of the features in the inkjet‐printed pattern as well as antibody functionality following inkjet printing. Uniform patterns that contained functional antibodies were fabricated using the piezoelectric inkjet printer. These results suggest that piezoelectric inkjet printing may be used to fabricate low‐cost disposable immunoassays for biotechnology and healthcare applications.
Calmodulin effects on steroids‐regulated plasma membrane calcium pump activity
Authors: Zylinska Ludmila , Kowalska Iwona , Ferenc Bozena
Published: February 2009

It is now generally accepted that non‐genomic steroids action precedes their genomic effects by modulation of intracellular signaling pathways within seconds after application. Ca2+is a very potent and ubiquitous ion in all cells, and its concentration is precisely regulated. The most sensitive on Ca2+increase is ATP‐consuming plasma membrane calcium pump (PMCA). The enzyme is coded by four genes, but isoforms diversity was detected in excitable and non‐excitable cells. It is the only ion pump stimulated directly by calmodulin (CaM). We examined the role of PMCA isoforms composition and CaM effect in regulation of Ca2+uptake by estradiol, dehydroepiandrosterone (DHEA), pregnenolone (PREG), and their sulfates in a concentration range from 10−9to 10−6 M, using the membranes from rat cortical synaptosomes, differentiated PC12 cells, and human erythrocytes. In excitable membranes with full set of PMCAs steroids apparently increased Ca2+uptake, although to a variable extent. In most of the cases, CaM decreased transport by 30–40% below controls. Erythrocyte PMCA was regulated by the steroids somewhat differently than excitable cells. CaM strongly increased the potency for Ca2+extrusion in membranes incubated with 17‐β‐estradiol and PREG. Our results indicated that steroids may sufficiently control cytoplasmic calcium concentration within physiological and therapeutic range. The response depended on the cell type, PMCA isoforms expression profile, CaM presence, and the steroids structure. Copyright © 2009 John Wiley & Sons, Ltd.
On‐Chip Fragment‐Based Approach for Discovery of High‐Affinity Bivalent Inhibitors
Authors: Miyazaki Isao , Simizu Siro , Ishida Keisuke , Osada Hiroyuki
Published: February 2009

Covalent bonds not required: We describe a novel approach in which the concepts of fragment‐based ligand discovery are combined with chemical array techniques to yield bivalent inhibitors. A pair of fragments is mixed and covalently attached to a glass slide by photolinking immobilization. The method does not require the compounds to have specific functional groups, and tedious steps for protein purification are avoided. Thus, the on‐chip fragment‐based approach is relatively simple and efficient for obtaining high‐affinity ligands.

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Synthesis of a Fluorogenic Analogue of Sphingosine‐1‐Phosphate and Its Use to Determine Sphingosine‐1‐Phosphate Lyase Activity
Authors: Bedia Carmen , Camacho Luz , Casas Josefina , Abad José Luis , Delgado Antonio , Van Veldhoven Paul P. , Fabriàs Gemma
Published: February 2009

Illuminating an ER enzyme: We report on the design and synthesis of a fluorogenic chemical sensor (1) to measure sphingosine‐1‐phosphate lyase activity in high‐throughput screening formats, as well as its validation using lyase knockout (Sgpl1−/−) cells.

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