bluuebunny/crossref_metadata_2025 huggingface dataset:
S19 ribosomal protein dimer augments metal‐induced apoptosis in a mouse fibroblastic cell line by ligation of the C5a receptor
Authors: Nishiura Hiroshi , Tanase Sumio , Shibuya Yoko , Futa Noriko , Sakamoto Tamami , Higginbottom Adrian , Monk Peter , Zwirner Jörg , Yamamoto Tetsuro
Published: November 2004

To analyze the role of S19 ribosomal protein (RP S19) in apoptosis, murine NIH3T3 were transfected with either hemagglutinin peptide‐tagged (HA) wild‐type human RP S19 or a mutant (Gln137Asn) that is resistant to transglutaminase‐catalyzed cross‐linked‐dimerization. Transfection with the mutant HA‐RP S19 inhibited manganese (II) (Mn II)‐induced apoptosis whereas the wild‐type HA‐RP S19 augmented apoptosis and a mock transfection had no effect. Release of the wild‐type HA‐RP S19 dimer but not the mutant HA‐RP S19 was observed during the apoptosis. The reduced rate of apoptosis of the cells transfected with the mutant HA‐RP S19 was overcome by addition of extracellular wild‐type RP S19 dimer. The apoptosis rates in cells transfected with either form of human HA‐RP S19 and in mock transfectants were reduced to about 40% by the presence of anti‐RP S19 antibody in the culture medium. Immunofluorescence staining and fluorescence‐activated cell sorting (FACS) analysis showed that the cell surface expression of the receptor for cross‐linked RP S19 dimer, C5a receptor, increased during apoptosis, concomitant with phosphatidylserine exposure. The expression of the C5a receptor gene also increased twofold. Apoptosis rates in the transfected and control cell lines were also reduced by the presence of an anti‐mouse C5a receptor monoclonal antibody or of a peptide C5a receptor antagonist. These results indicated the presence of an RP S19 dimer‐ and C5a receptor‐mediated autocrine‐type augmentation mechanism during Mn II‐induced apoptosis in the mouse fibroblastic cell line. In contrast to the RP S19 dimer, C5a actually inhibited apoptosis, suggesting that signaling through the C5a receptor varies depending on the ligand bound. © 2004 Wiley‐Liss, Inc.
Peroxisome proliferator‐activated receptor γ gene polymorphism is associated with serum triglyceride levels and body mass index in Japanese type 2 diabetic patients
Authors: Maeda Atsuko , Gohda Tomohito , Funabiki Kazuhiko , Horikoshi Satoshi , Tomino Yasuhiko
Published: November 2004

Peroxisome proliferator‐activated receptor γ (PPARγ) controls adipocyte differentiation and regulates lipid and glucose homeostasis. Therefore, the PPARγ gene may affect insulin sensitivity and resistance. We analyzed the relationship between C/T exon 6 polymorphism of the PPARγ gene and various clinical parameters in type 2 diabetic patients. There were no significant differences in the frequencies of genotype and allele between diabetic patients with and without nephropathy. Diabetic patients were divided into two groups: patients bearing at least one T allele (CT/TT), and patients with no T allele (CC). Levels of serum triglyceride and body mass index (BMI) were significantly higher in the CT/TT genotype group than in the CC genotype group. Since obesity affects insulin resistance, the diabetic patients were also divided into two groups: those with a BMI of <23, and those with a BMI of >23. In patients with a BMI of <23, there was no significant change in the levels of glycosylated hemoglobin A1c (HbA1c) between the CC and CT/TT genotype groups. However, in patients with a BMI of >23, HbA1c levels were significantly higher in the CT/TT genotype group than in the CC genotype group. It appears that the CT/TT genotype with PPARγ gene polymorphism may contribute to higher BMI and higher serum triglyceride and HbA1c levels in Japanese type 2 diabetic patients. J. Clin. Lab. Anal. 18:317–321, 2004. © 2004 Wiley‐Liss, Inc.
Early viral kinetics and treatment outcome in combination of high‐dose interferon induction vs. pegylated interferon plus ribavirin for naïve patients infected with hepatitis C virus of genotype 1b and high viral load
Authors: Tsubota Akihito , Arase Yasuji , Someya Takashi , Suzuki Yoshiyuki , Suzuki Fumitaka , Saitoh Satoshi , Ikeda Kenji , Akuta Norio , Hosaka Tetsuya , Kobayashi Masahiro , Kumada Hiromitsu
Published: November 2004

An investigation was carried out to determine whether early viral monitoring could predict efficiently the virological response to combination therapy of two different regimens in treatment‐naïve chronic hepatitis C patients infected with genotype 1b with high baseline viral load. Patients were randomly assigned to receive interferon (IFN) alpha‐2b induction (6 MU daily for 2 weeks) followed by 6 MU thrice weekly for 46 weeks (IFN/R group; n = 20), or pegylated IFN alpha‐2b (1.5 μg/kg) weekly for 48 weeks (PEG/R group; n = 28), in combination with ribavirin (600‐1,000 mg daily). Serum HCV RNA was quantitated at 0, 6, 12, 24, and 48 hr post‐dose, weekly during the first 4 weeks, and thereafter viral kinetics were assessed every 4 weeks. The sustained virological response rates in the IFN/R and PEG/R groups were 40% (8/20) and 43% (12/28), respectively. The non‐virological response rates were 40% (8/20) and 39% (11/28), respectively. The cumulative virological response rates were similar in both groups. Multivariate analyses identified no independent baseline variables linked to sustained virological or non‐virological response. Early log viral load changes from baseline in both groups were significantly greater at all time‐points after 24 hr in virological response patients than in non‐virological response patients (P < 0.001 for all). On the receiver operating characteristics curves for prediction of non‐virological response, the area under the curves (0.951–1.000), sensitivity (90%–100%), and negative predictive value (96%– 100%) were similar at any time‐points after 24 hr. For prediction of sustained virological response, sensitivity of 80% with 86% negative predictive value was observed for negative HCV RNA at week 12, with the highest area under the curves value of 0.919. The results suggest that early monitoring of viral kinetics is a useful measure to predict virological response, and might facilitate development of rational and effective therapeutic strategies. J. Med. Virol. 75:27–34, 2005. © 2005 Wiley‐Liss, Inc.
Mode of HCV infection examined by polymorphism of hypervariable region‐1 in cases of acute hepatitis C after accidental exposure to blood‐borne pathogens
Authors: Takeda Tadashi , Tatsumi Nobuyuki , Nakayama Yuji , Yasuda Takahiro , Nishiguchi Shuhei , Seki Shuichi
Published: November 2004

Acute hepatitis C is known to respond better to interferon therapy than chronic hepatitis C. The reason for this difference remains unclear. The present study was undertaken to examine HCV quasispecies in blood from patients with acute hepatitis C caused by accidental exposure to blood‐borne pathogens and in blood from the source patients. Three patients who developed hepatitis C (recipient patients; R‐Pt.) and two patients who served as a source of HCV infection (source patients; S‐Pt.) were the subjects of this study. The number of quasispecies and the genetic diversity in hypervariable region‐1 (HVR‐1) were examined on the basis of fluorescence single‐strand conformation polymorphism and sequence analysis (FSSA). On the day of the accident, the number of quasispecies and genetic diversity were 13 and 36 in S‐Pt.1 and 6 and 20 in S‐Pt.3, respectively. At the time of diagnosis of acute hepatitis, the number of quasispecies and nucleotide diversity were 2 and 2 in R‐Pt.1, 2 and 0 in R‐Pt.2, and 4 and 0 in R‐Pt.3, respectively. Immediately before the start of treatment, the number of quasispecies and genetic diversity were 4 and 4 in R‐Pt.1, 2 and 0 in R‐Pt.2, and 3 and 0 in R‐Pt.3., respectively. In three R‐Pts, interferon therapy resulted in eradication of HCV. These findings indicate that in the early stage of HCV infection, only a portion of HCV transmitted from S‐Pts to R‐Pts can proliferate. The low number of quasispecies of HCV appears to be one of the reasons why acute hepatitis responds well to interferon therapy. J. Med. Virol. 75:35–41, 2005. © 2005 Wiley‐Liss, Inc.
Phylogenetic analysis of hepatitis A virus in Thailand
Authors: Wattanasri Naiyana , Ruchusatsawat Kriangsak , Wattanasri Somsak
Published: November 2004

Human hepatitis A virus (HAV) is a major causative agent of acute hepatitis, and the isolates are categorised into four genotypes: I (GI), II (GII), III (GIII), and VII (GVII). Although viral hepatitis has been detected under a nationwide surveillance system in Thailand, the genetic variation of HAV has not yet been determined. In the present study, serum specimens were collected from acute hepatitis patients in Thailand from 1998–2002. The IgM‐class antibody to HAV was detected in 156 out of 394 sera, counting as many as 39.6% of acute viral hepatitis cases. HAV RNA in the serum specimens was amplified by reverse‐transcription polymerase chain reaction (RT‐PCR), and a phylogenetic analysis of the putative VP1/2A junction of the genome was performed.

The isolates were grouped into two genetic groups, GIA and GIB. This is the first report to identify subgenotype IB (GIB) in Thailand. The genetic segregation was closely related to the province where hepatitis A occurred and the serum specimens were collected. In addition, genetically similar strains were identified in both 1998 and 2001–2002 isolates from two close provinces in the southern part of Thailand, suggesting that a strain indigenous to the province or district has been circulating in southern Thailand. J. Med. Virol. 75:1–7, 2005. © 2005 Wiley‐Liss, Inc.
Association between enterovirus endomyocardial infection and late severe cardiac events in some adult patients receiving heart transplants
Authors: Douche‐Aourik Fatima , Bourlet Thomas , Mosnier Jean‐François , Jacques Jérôme , Decoene Christophe , Stankowiak Czeslas , Pozzetto Bruno , Andréoletti Laurent
Published: November 2004

Enteroviruses and other cardiotropic viruses have been associated with the development of late severe adverse cardiac events in infants receiving heart transplants. However, the source and the chronology of cardiac allograft infection by an enterovirus in patients receiving heart transplants remain unknown. Using RT‐PCR and immunohistochemistry assays, endomyocardial tissue samples of 30 adult patients were tested to detect the presence of specific enterovirus 5′ non‐coding (5′NC) sequences and of VP1 capsid protein, and this at the time of cardiac transplantation and at the 12‐month biopsy for graft rejection control. Moreover, the endomyocardial detection of genomic sequences of enteroviruses, Epstein–Barr virus, herpes simplex virus, cytomegalovirus (CMV), varicella‐zoster virus, adenoviruses, and parvovirus B19 was carried out by RT‐PCR and polymerase chain reaction (PCR) assays at the time of late severe cardiac events. Enterovirus RNA and VP1 antigen were both detected in 4 (13%) of 30 patients at the time of the 12‐month biopsy for graft rejection control, whereas no enterovirus component was detected in the explanted and implanted heart tissues taken from these 4 patients at the time of transplantation. At the time when severe cardiac events were developed, within 3 months after the positive enterovirus cardiac detection, these four patients demonstrated the presence of endomyocardial enterovirus RNA sequences whereas they were tested negative for the endomyocardial detection of genomic sequences from DNA viruses (except for CMV in two cases), and for a significant level of pp65 CMV antigenemia. Taken together, these findings indicate that enteroviruses could be acquired as a new endomyocardial infection within 12 months after transplantation in adults receiving heart transplants, and suggest that this infection might be an etiological cause for unexplained late severe adverse cardiac events in the heart‐transplantated adults. J. Med. Virol. 75:47–53, 2005. © 2005 Wiley‐Liss, Inc.
In vitro and in vivo analysis of human herpesvirus‐6 U90 protein expression
Authors: Nishimura N. , Yoshikawa T. , Ozaki T. , Sun H. , Goshima F. , Nishiyama Y. , Asano Y. , Kurata T. , Iwasaki T.
Published: November 2004

In order to establish a reliable method for the detection of human herpesvirus‐6 (HHV‐6) B antigens in peripheral blood mononuclear cells (PBMCs) collected from HHV‐6 infected patients, we created a polyclonal antibody against the HHV‐6 B U90 protein (IEA/ex3) and used it to examine the expression of this protein in virus‐infected cells and patients' PBMCs. This antibody reacted with 170 and 195 kDa proteins in HHV‐6 B‐infected cord blood mononuclear cells. The IEA/ex3 antigen was detected in cord blood mononuclear cells at 6 hr post‐infection, and the number of infected cells reached its maximum at 48 hr post‐infection. The antigen stained in a punctate pattern and partially localized to the promyelocytic leukemia (PML) protein body. We also examined 60 PBMC samples from 60 febrile children (3–19 months old) and detected IEA/ex3 antigen in the PBMCs by laser‐scanning microscopy. HHV‐6 was isolated from 31 of the 60 samples. The sensitivity and specificity of the antigen detection were 84% (26/31) and 97% (28/29), respectively, in the samples with virus detected. The mean number of antigen‐positive PBMCs was 409/106 cells in 20 samples with viral isolation. A significant correlation (r = 0.566; P = 0.008) was observed between the viral load and number of antigen‐positive cells. Although IEA/ex3 antigen was detected by laser‐scanning microscopy in PBMCs (without cultivation) collected from six patients with isolated virus, it was detected in only one sample by conventional fluorescence microscopy. Increasing the intensity by cultivation (24 hr) resulted in a higher detection rate (5/6) even by conventional fluorescence microscopy, which is available in most hospital laboratories. J. Med. Virol. 75:86–92, 2005. © 2005 Wiley‐Liss, Inc.
Identification of epitopes in the nucleocapsid protein of Nipah virus using a linear phage‐displayed random peptide library
Authors: Eshaghi Majid , Tan Wen Siang , Yusoff Khatijah
Published: November 2004

A random peptide library of heptamers displayed on the surface of M13 bacteriophage was used to identify specific epitopes of antibodies in pooled sera of swine naturally infected by Nipah virus. The selected heptapeptides were aligned with protein sequences of Nipah virus and several putative epitopes were identified within the nucleocapsid protein. A total of 41 of 60 (68%) selected phage clones had inserts resembling a region with the sequence SNRTQGE, located at the C‐terminal end (amino acids 503–509) of the nucleocapsid protein. The binding of antibodies in the swine and human antisera to the phage clone was inhibited by a synthetic peptide corresponding to this region. Epitopes identified by phage display are consistent with the predicted antigenic sites for the Nipah virus nucleocapsid protein. The selected phage clone used as a coating antigen discriminated swine and human Nipah virus sera‐positive from sera‐negative samples exhibiting characteristics, which might be attractive for diagnostic tests. J. Med. Virol. 75:147–152, 2005. © 2005 Wiley‐Liss, Inc.
Pregnenolone sulfate enhances long‐term potentiation in CA1 in rat hippocampus slices through the modulation of N‐methyl‐D‐aspartate receptors
Authors: Sliwinski A. , Monnet F.P. , Schumacher M. , Morin‐Surun M.P.
Published: November 2004

Among the different steroids found in the brain, pregnenolone sulfate (3β‐hydroxy‐5‐pregnen‐20‐one‐3‐sulfate; PREGS) is known to enhance hippocampal‐associated memory. The present study employs rat hippocampal slices to investigate the ability of PREGS to modulate long‐term potentiation (LTP), a phenomenon considered as a model of synaptic plasticity related to memory processes. LTP (3 × 100 Hz/1 sec within 2 min), implicated essentially glutamatergic transmission, for which the different synaptic events could be pharmacologically dissociated. We show that PREGS enhances LTP in CA1 pyramidal neurons at nanomolar concentrations and exhibits a bell‐shaped concentration‐response curve. The maximal effect of PREGS on both induction and maintenance phases of LTP is observed at 300 nM and requires 10 min of superfusion. Although PREGS does not change the N‐methyl‐D‐aspartate (NMDA) component of the field potentials (fEPSPs) isolated in the presence of 10 μM 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX) in Mg2+‐free artificial cerebrospinal fluid, PREGS does enhance the response induced by NMDA application (50 μM, 20 sec). PREGS does not modify the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) component of the fEPSPs isolated in the presence of 100 μM DL‐2‐amino‐7‐phosphopentanoic acid (DL‐AP5) or its potentiation induced by a single tetanic stimulation and the response induced by AMPA application (10 μM, 10 sec). Furthermore, PREGS does not affect the recurrent inhibition of the fEPSPs mediated by γ‐aminobutyric acid type A (GABAA) receptor. In conclusion, this study shows the ability of PREGS to enhance LTP in CA1 by accentuating the activity of NMDA receptors. This modulation of LTP might mediate the steroid‐induced enhancement of memory. © 2004 Wiley‐Liss, Inc.
Zonal circulations over the Indian and Pacific Oceans and the level of lakes Victoria and Tanganyika
Authors: Bergonzini Laurent , Richard Yves , Petit Lena , Camberlin Pierre
Published: November 2004

Level records of two East African Great Lakes, Lake Victoria and Lake Tanganyika, which are considered as hydro‐climatic proxies, are analysed. Comparisons between the two lake signals show synchronisms, which can only be accounted for by large‐scale mechanisms. Lake‐level variations associated with the short rains season (October–January) appear to have a prominent effect on the annual lake levels. The relations between lake‐level variations and atmospheric circulation indexes are then investigated. Over the period 1946–2000, four indexes are selected to characterize the October–December zonal circulation over the Pacific and Indian Oceans. Over the Indian Ocean two surface zonal wind indexes (ZWIs) are used. For the Pacific, the southern oscillation index (SOI) and the Niño3 index are held to account for the El Niño–southern oscillation (ENSO). It is shown that significant overall negative correlations of level fluctuations are preferentially obtained with Indian Ocean circulation indexes. Although ZWI is highly correlated with the ENSO indexes, the latter display weaker relations with East African lake levels. It is shown that, for the 1946–2000 period, the October–December zonal circulation cell over the Indian Ocean plays a key role in the equatorial lake‐level anomalies, thus demonstrating their influence on the hydro‐climatic interannual variability of a large region. However, lake‐level variation is a function not only of regional hydro‐climatic conditions, but also of the initial (October) absolute lake level. Higher correlations are evident in a multiple correlation approach taking into account the initial lake level status in addition to the ZWI and ENSO indexes. Copyright © 2004 Royal Meteorological Society
Spectator ligand effects on the vibrational spectra of heteroleptic complexes of ruthenium with bipyrazine
Authors: Wu Jing , Kincaid James R.
Published: November 2004

Resonance Raman (RR) and transient resonance Raman (TR2) spectra were acquired for a series of heteroleptic complexes of ruthenium, i.e. RuL2(bpz)2+, where bpz is 2,2′‐bipyrazine and L is 2,2′‐bipyridine (bpy) or an alkylated 2,2′‐bipyridine [i.e. diazafluorene (daf) or 4,4′‐dimethyl‐5,5′‐diethyl‐2,2′‐bipyridine (dmdeb)]. Resonance Raman spectra acquired at different excitation wavelengths for the ground‐state complexes reveal selective enhancement of modes associated with the coordinated bpz or the spectator ligands, as expected. The TR2 spectra, acquired with excitation at 355 nm, confirm selective population of a bpz‐localized 3MLCT excited state for each complex. Both the ground‐state RR spectra and the excited state TR2 data indicate that only slight shifts are observed in a few modes as the donor strengths of the spectator ligands are varied. Such data for a systematically manipulated set of complexes, acquired here for the first time, imply that both the RR and TR2 spectral parameters are reliably characteristic for a given ligand, varying only slightly as the nature of other ligands in the complex is changed. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of seed treatments on the chemical composition and properties of two amaranth species: starch and protein
Authors: Gamel Tamer H , Linssen Jozef P , Mesallem Ahmed S , Damir Ahmed A , Shekib Lila A
Published: November 2004

The seeds of two Amaranth species were studied. The starch contents were 543 and 623 g kg−1 while crude protein contents were 154 and 169 g kg−1 for Amaranthus caudatus and Amaranthus cruentus seeds, respectively. The effect of several treatments, including cooking, popping and germination and flour air classification on the protein and starch properties were studied. Air classification decreased the starch content and increased the protein content, while heating increased the protein but did not affect the starch content. Germination decreased both starch and protein contents. Amylose content was increased by air classification and heating, but was not affected by germination. It was found that all treatments increased the starch swelling power and reduced the falling number. The resistant starch content was increased in the high protein flour (HPF) fraction and germinated flour compared with the raw flour, while its content decreased in the heat treated seed flours. These processes also affected the starch gelatinization temperature and peak viscosity. The thermal properties of the starch flour were not affected by air classification while gelatinization energy was decreased significantly (by 52.0 and 90.0% and by 70.0 and 95.0%) in cooked and popped A caudatus and A cruentus seed flours, respectively. The gelatinization energy was highest in germinated seeds dried at 90 °C with values of 2.67 and 3.87 J g−1. Air classification reduced the level of all protein fractions. Thermal treatment decreased the water‐soluble fraction (albumins + globulins) and alcohol‐soluble fraction (prolamins) in both species. The levels of all fractions except the water‐soluble fraction (albumins + globulins) were reduced significantly in both species by germination, which mainly increased the amount of aspartic acid, serine and alanine, while the amounts of threonine, arginine and tyrosine decreased in both species. The polypeptide bands of the HPF in both species were unchanged compared with the raw seed flours, but more intensive coloured bands were observed. Thermal treatments eliminated major and minor bands above 35.0 KDa in both species. Copyright © 2004 Society of Chemical Industry
Interaction between lactose levels and antimicrobial growth promoters on growth performance of weanling pigs
Authors: O'Doherty JV , Nolan CS , McCarthy PC
Published: November 2004

In experiment 1, 224 pigs (initially 8.85 kg and 28 ± 2 days of age) were used in a 2 × 2 factorial arrangement of treatments to investigate the interaction between lactofeed (LF70) (860 g kg−1 whey permeate, 140 g kg−1 soya bean meal) level (175 g kg−1 and 350 g kg−1) and avilamycin (0 and 40 mg kg−1) inclusion in piglet starter diets. Pigs were fed starter diets from day 0 to day 22 and a transition diet was fed from day 23 to day 39. The inclusion level of LF70 in the transition diet was 75 g kg−1 and 150 g kg−1. Pigs fed 350 g kg−1 LF70 had a higher daily gain (ADG) (p < 0.01) and an improved feed conversion ratio (FCR) (p < 0.05) during the starter period than the pigs fed 175 g kg−1 LF70. Pigs fed medicated diets had a higher ADG (p < 0.05) and an improved FCR (p < 0.05) than the non‐medicated fed pigs during the starter period. There was an increase in feed intake (AFI) (p < 0.05) during the transition period with increasing levels of LF70. There was an improvement in FCR during the transition period with the inclusion of avilamycin (p < 0.01). There was a significant interaction (p < 0.01) between LF70 and avilamycin for ADG during the transition period. The inclusion of avilamycin at 175 g kg−1 LF70 inclusion had no effect (p > 0.05) on ADG. However at 350 g kg−1 LF70 inclusion the pigs offered medicated diets had a higher ADG (p < 0.001) compared with non‐medicated diets. In experiment 2, 224 pigs (initially 8.85 kg and 28 ± 2 days of age) were used in a 2 × 2 factorial to investigate the interaction between LF70 level (175 g kg−1 and 350 g kg−1) and zinc oxide (ZnO) (0 and 3.1 g kg−1) inclusion in piglet starter diets. The inclusion level of LF70 in the transition diet was 75 g kg−1 and 150 g kg−1 and of ZnO was 2 g kg−1. There was a significant increase (p < 0.05) in ADG with increasing levels of LF70 during the starter period. The inclusion of ZnO during the starter period resulted in an increase in ADG (p < 0.001) and FCR (p < 0.05) compared with no ZnO inclusion. Neither the inclusion of zinc oxide not of LF70 had an effect (p > 0.05) on performance during the transition period. In conclusion the supplementation of starter diets with increasing levels of LF70, ZnO and avilamycin resulted in increased ADG and improved FCR. Copyright © 2004 Society of Chemical Industry
Mutation Effects of a Conserved Alanine (Ala510) in Type I Polyhydroxyalkanoate Synthase from Ralstonia eutropha on Polyester Biosynthesis
Authors: Tsuge Takeharu , Saito Yu , Narike Masaharu , Muneta Koho , Normi Yahaya M. , Kikkawa Yoshihiro , Hiraishi Tomohiro , Doi Yoshiharu
Published: November 2004

Summary: Type I polyhydroxyalkanoate (PHA) synthases, as represented by Ralstonia eutropha enzyme (PhaCRe), have narrow substrate specificity toward (R)‐3‐hydroxyacyl‐coenzyme A with acyl chain length of C3‐C5 to yield PHA polyesters. In this study, saturation point mutagenesis of a highly conserved alanine at position 510 (A510) in PhaCRe was carried out to investigate the effects on the polymerization activity and the substrate specificity for in vivo PHA biosynthesis in bacterial cells. A series of saturation mutants were first applied for poly[(R)‐3‐hydroxybutyrate] homopolymer synthesis in Escherichia coli and R. eutropha PHB−4 (PHA negative mutant) cells to assess the polymerization activity. All mutants showed quantitatively similar polymerization activities when R. eutropha PHB−4 was used for assay, whereas several mutants such as A510P showed low activities in E. coli. Further analysis has revealed that majority of mutants synthesize polyesters with higher molecular weights than the wild‐type. In particular, substitution by acidic amino acids, A510D(E), led to remarkable increases in molecular weights. Subsequently, PHA copolymer synthesis from dodecanoate (C12 fatty acid) was examined. The copolymer compositions were varied depending on the mutants used. Significant increased fractions of long monomer units (C6 and C8) in PHA copolymers were observed for three mutants [A510M(Q,C)]. From these results, the mutations at this potion are beneficial to change the molecular weight of polyesters and the substrate specificity of PhaCRe.

Molecular weight distributions of PHA polymers synthesized by the wild‐type enzyme (PhaCRe) and its mutants.

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Molecular weight distributions of PHA polymers synthesized by the wild‐type enzyme (PhaCRe) and its mutants.
Cover Picture: Macromol. Biosci. 10/2004
Authors: Osanai Yasushi , Toshima Kazunobu , Matsumura Shuichi
Published: November 2004

Cover: The conceptual scheme shows the lipase‐catalyzed green chemical recycling of biodegradable polyesters and the equipment for the continuous enzymatic degradation of biodegradable polyesters, using the enzyme column. The typical chemically‐synthesized biodegradable plastics, such as poly(butylene adipate) and poly(ε‐caprolactone), were degraded and transformed quantitatively into a repolymerizable cyclic oligomer passing through the enzyme packed column under continuous flow. And it was confirmed that the degradation activity of the enzyme column was maintained for at least six months at 40 °C.

Further details can be found in the Full Paper by Y. Osanai, K. Toshima, and S. Matsumura* on page 936.
Untersuchungen zum Einfluss des Stickstoffs auf das Lochkorrosionsverhalten hochlegierter austenitischer Cr‐Ni‐Mo‐Stähle (Teil II)
Authors: Eckstein Ch. , Spies H. J. , Albrecht J.
Published: November 2004

Die Ermittlung des statischen Lochkorrosionspotentials an Chrom‐Nickelstählen des Typs 18/12 ohne und mit steigenden Molybdängehalten sowie abgestuften Stickstoffgehalten erlaubte eine quantitative Bewertung des Einflusses von Stickstoff auf die Lochkorrosionsbeständigkeit. Es zeigte sich, dass die spezifische Wirkung des Stickstoffs zwischen 0,04 und 0,42 Masse% bei sonst völlig gleicher Zusammensetzung im Bereich von 0,06 bis 3,6 Masse% Mo nicht vom Molybdängehalt abhängt und in allen Legierungsgruppen nahezu gleich ist. Sie kann in der Wirksumme durch den Faktor 25 beschrieben werden. Durch Oberflächenuntersuchungen mittels XPS‐Analyse waren sowohl bei molybdänfreiem als auch bei molybdänhaltigem Stahl die passivierungswirksamen Komplexe des Stickstoffs nachzuweisen, so dass angenommen werden kann, dass bei allen untersuchten Legierungen Stickstoff die Lochkorrosionsbeständigkeit nach dem gleichen Mechanismus verbessert.

Die durchgeführten Untersuchungen zeigten, dass unter den gewählten Prüfbedingungen die in letzter Zeit häufig vertretene Auffassung [2–6] über einen Synergieeffekt von Molybdän und Stickstoff nicht bestätigt werden kann. Damit werden Bemühungen unterstützt, auch bei molybdänarmen Stählen die Lochkorrosionsbeständigkeit durch Randaufsticken bzw. Auflegieren mit Stickstoff zu verbessern.

Die erzielten Ergebnisse berechtigen zu der Annahme, dass der beobachtete positive Effekt des Stickstoffs zu noch höheren Stickstoffgehalten extrapolierbar ist. Voraussetzung dafür ist allerdings das Vermeiden von Sekundärphasen in der Matrix, deren abmindernder Einfluss bekannt ist.
Synergistic or additive corrosion inhibition of mild steel by a mixture of HEDP and metasilicate at pH 7 and 11
Authors: Mohammedi D. , Benmoussa A. , Fiaud C. , Sutter E. M. M.
Published: November 2004

Electrochemical measurements (steady‐state current‐voltage curves and AC impedance) were coupled with mass‐loss measurements, SEM examinations, and EDSX analyses to investigate the inhibition of corrosion of a carbon steel by a mixture of phosphonic acid HEDP (acid 1, hydroxyethylene, 1‐1 diphosphonic) and sodium metasilicate pentahydrate Na2SiO3. 5H2O in an industrial hard water containing 3.10−3 M Ca2+ ions. At pH 7, HEDP and Ca2+ act in a synergistic manner, by formation of a HEDP and calcium containing layer. Addition of silicate at this pH value, allows to reach an efficiency of 94% due to an additive inhibition effect. At pH 11, metasilicate, HEDP, and Ca2+ ions reinforce the passive layer in a synergistic way. The mixture (1.7 · 10−5 M HEDP + 2.6 · 10‐3 M SiO2−3) in the Ca2+ containing electrolyte is shown to be able to inhibit efficaciously the corrosion of iron at room temperature, considering uniform corrosion at pH 7 or pitting corrosion at pH 11.
Distinguishing Linear from Star‐Branched Polystyrene Solutions with Fourier‐Transform Rheology
Authors: Neidhöfer Thorsten , Sioula Stella , Hadjichristidis Nikos , Wilhelm Manfred
Published: November 2004

Summary: Fourier‐Transform rheology (FT rheology) was used to study the influence of the degree of branching on the nonlinear relaxation behaviour of polystyrene solutions. The results were compared with those obtained under oscillatory shear and step‐shear conditions. The different topologies could be distinguished using FT rheology where the other rheological measurements failed. Significant differences occurred under large amplitude oscillatory shear (LAOS) conditions as particularly reflected in the phase difference of the third harmonic, Φ3, which could be related to strain‐softening and strain‐hardening behaviour. Currently, this work is extended towards different topologies in polyolefins (e.g. long chain branched).

Phase difference Φ3 as a function of the Deborah number De at γ0 = 2 for the polystyrene solutions measured at temperatures from 295 to 350.5 K.

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Phase difference Φ3 as a function of the Deborah number De at γ0 = 2 for the polystyrene solutions measured at temperatures from 295 to 350.5 K.
Single‐Mode Microwave Ovens as New Reaction Devices: Accelerating the Living Polymerization of 2‐Ethyl‐2‐Oxazoline
Authors: Wiesbrock Frank , Hoogenboom Richard , Abeln Caroline H. , Schubert Ulrich S.
Published: November 2004

Summary: The ring‐opening cationic polymerization of 2‐ethyl‐2‐oxazoline was performed in a single‐mode microwave reactor as the first example of a microwave‐assisted living polymerization. The observed increase in reaction rates by a factor of 350 (6 h → 1 min) in the range from 80 to 190 °C could be attributed solely to a temperature effect as was clearly shown by control experiments and the determined activation energy. Because of the homogenous microwave irradiation, the polymerization could be performed in bulk or with drastically reduced solvent ratios (green chemistry).

Monomer conversion, represented by the ratio ln{[M0]/[Mt]}, plotted against time for six temperatures in the range from 80 to 180 °C, and polymerization reaction vials, showing an increase in yellow color for those reactions performed (well) above and below 140 °C, indicating side reactions.

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Monomer conversion, represented by the ratio ln{[M0]/[Mt]}, plotted against time for six temperatures in the range from 80 to 180 °C, and polymerization reaction vials, showing an increase in yellow color for those reactions performed (well) above and below 140 °C, indicating side reactions.
Chain Transfer and Efficiency of End‐Group Introduction in Free Radical Polymerization of Methyl Methacrylate in the Presence of Poly(methyl methacrylate) Macromonomer
Authors: Miyake Kazuki , Zetterlund Per B. , Yamada Bunichiro
Published: November 2004

Summary: Experimental and modeling studies of addition–fragmentation chain transfer (AFCT) during radical polymerization of methyl methacrylate in the presence of poly(methyl methacrylate) macromonomer with 2‐carbomethoxy‐2‐propenyl ω‐ends (PMMA‐CO2Me) at 60 °C are reported. The results revealed that AFCT involving PMMA‐CO2Me formed in situ during methyl methacrylate polymerization has a negligible effect on the molecular weight distribution.

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Cover Picture: Macromol. Rapid Commun. 22/2004
Authors: Mahajan Surbhi , Cho Byoung‐Ki , Allgaier Jürgen , Fetters Lewis J. , Coates Geoffrey W. , Wiesner Ulrich
Published: November 2004

Cover: The cover shows the molecular architecture of the A block, poly(ethylene‐alt‐propylene), and the AB diblock, poly(ethylene‐alt‐propylene)‐block‐poly(ethylene oxide), leading to the final ABC triblock copolymer, poly(ethylene‐alt‐propylene)‐block‐poly‐(ethylene oxide)‐block‐poly(hexyl methacrylate). Oxygen containing segments are shown in red. The corresponding GPC chromatograms reveal narrow molecular weight distributions for all the species.

Further details can be found in the Communication by S. Mahajan, B.‐K. Cho, J. Allgaier, L. J. Fetters, G. W. Coates, and U. Wiesner* on page 1889.
Synthesis of Hyperbranched Polysaccharide by Thermally Induced Cationic Polymerization of 1,6‐Anhydrohexopyranose
Authors: Satoh Toshifumi , Imai Tomoko , Kitajyo Yoshikazu , Maeda Takahiro , Narumi Atsushi , Kaga Harumi , Kaneko Noriaki , Kakuchi Toyoji
Published: November 2004

The thermally induced cationic polymerizations of 1,6‐anhydro‐β‐D‐glucopyranose (1a), 1,6‐anhydro‐β‐D‐mannopyranose (1b) and 1,6‐anhydro‐β‐D‐galactopyranose (1c) as a latent cyclic AB4‐type monomer were carried out using (S‐2‐butenyl)tetramethylenesulfonium hexafluoroantimonate (2) as an initiator. The solution polymerization in propylene carbonate proceeded without gelation to produce the water‐soluble hyperbranched polysaccharides (3a‐c) with controlled molecular weights and narrow polydispersities. The degree of branching (DB), estimated by the methylation analysis of 3a‐c, was in the range of 0.38 – 0.49. The thermally induced cationic polymerization of 1a‐c using 2 is a facile method leading to a hyperbranched polysaccharide with a high DB value.
New Monomers for Dental Application
Authors: Moszner Norbert
Published: November 2004

The currently used commercial restoratives composites and self‐etching enamel‐dentin adhesives usually contain various functionalised and cross‐linking methacrylates. New developments of polymeric composites for restorative filling materials are mainly focused on the reduction of the polymerization shrinkage and improvement of biocompatibility and wear resistance. This can be partially achieved by using new monomers, for example, cyclic monomers for the radical polymerisation such as bicyclic cyclopropyl‐acrylates or polycondensates generated by the hydrolytic condensation of triethoxypropylsilane dimethacrylates. In the presence of water and strongly acidic monomers, methacrylates undergo hydrolysis, which results in decrease of the performance of the adhesive. This problem can be overcome with new polymerizable acrylic phosphonic acids and cross‐linking bis(acrylamide)s, which show improved hydrolytic stability.
Poly(acrylamide) Grafts on Spherical Polymeric Sulfonamide Based Resin for Selective Removal of Mercury Ions from Aqueous Solutions
Authors: Şenkal Bahire Filiz , Yavuz Erdem , Bicak Niyazi
Published: November 2004

Poly (acrylamide) was grafted from carboxylic acid groups onto cross linked poly (styrene) beads using a redox polymerization methodology. A beaded polymer with a poly(acrylamide) surface shell was prepared in three steps, starting from poly(styrene‐divinyl benzene) (PS‐DVB) (10% crosslinking) based beads with a particle size of 420‐590μm, according to the synthetic protocol; chlorosulfonation, sulfamidation with glycine and grafting using a concentrated aqueous acrylamide solution with cerium ammonium nitrate.

The resulting polymer resin with 220 wt % of grafted poly (acrylamide) has been demonstrated to be an efficient mercury‐specific sorbent, able to remove Hg (II) from solutions at ppm levels. The mobility of the graft chains provides nearly homogenous reactions conditions and rapid mercury binding ability. The mercury sorption capacity under non‐buffered conditions is around 5.75 mmol/g. No interference arises from common metal ions such as Cd (II), Fe (II), Zn (II), and Pb (II).The sorbed mercury can be eluted by repeated treatment with hot acetic acid without hydrolysis of the amide groups.
Preparation of Polymer‐Supported Chiral 1,2‐Diamine as an Efficient Ligand for Asymmetric Hydrogenation Catalyst
Authors: Itsuno Shinichi , Takahashi Miyuki , Tsuji Atsushi
Published: November 2004

An enantiopure 1,2‐diamine having two phenolic hydroxy groups was synthesized, and attached to chloromethylated poly(styrene) through a benzyl ether linkage. The polymer‐supported Ru precatalysts were prepared from the polymeric chiral 1,2‐diamine and RuCl2/BINAP complex. In the presence of t‐BuOK the polymeric catalyst system worked well in asymmetric hydrogenation of aromatic ketones in a mixed solvent of 2‐propanol and DMF. The insoluble polymeric catalyst was readily separated from the reaction mixture and reused at least several times without loss of the catalytic activity.
Design and Application of Amphiphilic Polymeric Supports for Micellar Catalysis
Authors: Kotre Thomas , Zarka M. Tobias , Krause Jens O. , Buchmeiser Michael R. , Weberskirch Ralf , Nuyken Oskar
Published: November 2004

In this contribution, the synthesis and application of amphiphilic poly(2‐oxazoline)s with covalently bound transition metal catalysts for reactions in aqueous media is described. In the first example, bipyridine moieties were introduced via living ring‐opening polymerization of functionalized oxazoline monomers and the resulting block copolymers were used as macroligands for ATRP (atom transfer radical polymerization) using Cu(I)Br as active metal species. Furthermore, the fixation of a chiral biphosphane and its use for enantioselective hydrogenation of enamides is presented as well as the fixation of a ruthenium catalyst. The latter one is used for polymerization of diethyl dipropargylmalonate (DEDPM), and represents the first example of an alkyne polymerization using a ruthenium catalyst. In the case of the polymers stable latex particles were obtained
Surface‐Initiated Polymerization on Self‐Assembled Monolayers: Effect of Reaction Conditions
Authors: Schmelmer Ursula , Paul Anne , Küller Alexander , Jordan Rainer , Gölzhäuser Armin , Grunze Michael , Ulman Abraham
Published: November 2004

Self‐assembled monolayers of 4′‐nitro‐4‐mercaptobiphenyl were modified by electron beam irradiation and diazotization to create a surface‐bond asymmetric azo initiator for the surface‐initiated polymerization (SIP). The effect of different reaction conditions upon the thermally and photochemical initiated SIP was investigated.
Synthesis and Self Assembly of Hydrogen‐Bonded Supramolecular Polymers
Authors: Farnik Dominique , Kluger Christian , Kunz Michael J. , Machl Doris , Petraru Laura , Binder Wolfgang H.
Published: November 2004

New synthetic methodologies towards hydrogen bonded supramolecular polymers are described. Focus is directed on synthetic work towards telechelics with hydrogen bonds either as side chain moieties or as endgroups. Physical ordering effects related to polymers and particles are discussed citing own and related work in ∼60 references.
Pseudostationary Polymerization: Improving the Determination of the Rate Constant of Propagation
Authors: Zifferer Gerhard , Kornherr Andreas , Schnöll‐Bitai Irene , Olaj Oskar Friedrich
Published: November 2004

Pulsed‐laser initiated polymerization (PLP) leads to chain length distributions with characteristic extrapeaks. The low molecular weight side points of inflection LLPI are located near to (multiples) of a specific chain length L0 which is equal to the product of pulse separation t0 and propagation frequency kp[M], i.e. rate constant of propagation kp times monomer concentration [M], allowing a direct determination of kp. However, Poissonian broadening inherent in the polymerization process as well as Gaussian broadening due to axial dispersion caused by the size exclusion chromatographic (SEC) device leads to a shift of LLPI as compared to L0 – its extent depending on the experimental parameters chosen – which in turn causes an error up to 10–20% in the rate constants evaluated. Fortunately, comparison of the experimental peak width with some sort of theoretical peak width yields several types of correction factors and furthermore master‐correction functions which are able to reduce the remaining error on average by at least a factor of 10.
Morphology – Property Correlations of PP Materials by Means of Microhardness
Authors: Seidler Sabine , Koch Thomas
Published: November 2004

The present work deals with the influence of crystallization temperature, cooling rate and annealing conditions on microhardness, indentation modulus and creep behaviour of ethylene/propylene (E/P) random copolymers with 4, 6 and 8 mol% ethylene as well as α‐ and β‐spherulites in a homopolymer and an E/P random copolymer. The materials are unnucleated, the formation of β‐spherulites occurs sporadically. Additionally the indentation creep behaviour of α‐ and β‐nucleated PP is investigated.

A nearly linear correlation between hardness as well as indentation modulus and crystallintity of the E/P copolymers can be proved. An increasing cooling rate leads to decreasing hardness and modulus values due to the hindered crystallization.

For the investigation of the α‐ and β‐phases different crystallization and annealing temperatures are used. Independent of these conditions, microhardness and modulus determined by indentation testing are lower for the β‐phase in both materials. Increasing crystallization temperature and annealing lead to an increasing hardness and modulus in both phases. However, an effective annealing effect takes place only at short times and elevated temperatures above 100 °C. The increasing of microhardness and modulus is correlated with an increasing in lamellae thicknesses. Additionally, indentation creep experiments were carried out on nucleated materials that show the stronger creep tendency of the β‐phase PP and the stronger influence of annealing on this phase.
Microphotometric Detection of Particles/Inhomogeneities in Flowing Polymer Melts
Authors: Stephan Michael , Große Stephan , Stintz Michael , Blankschein Udo , Rudolph Andreas
Published: November 2004

By application of different unique microphotometric sensors it is possible to detect and quantify disturbing particles (gels, unmolten resins, black spots, additive agglomerates, bubbles) within a flowing polymer melt in realtime during extrusion processing. These particles result in disadvantageous optical and mechanical properties of a final polymer product. Sensors can be adapted inline and online to different extruders at various positions. This seems to give technical and economic benefit to quality control and process optimisation in polymer processing.
An Experimentally Fast and Straightforward Method for the Direct Determination of Axial Dispersion σAd as Occurring in Size Exclusion Chromatography
Authors: Schnöll‐Bitai Irene
Published: November 2004

The method for the direct determination of σad (the extent of axial dispersion) under normal working conditions makes use of the peak variance of Poisson distributions and narrow peaks, which can be determined from the points of inflection. For such distributions the experimentally measured peak variance is the sum of the pristine or true peak variance and that stemming from the broadening processes during SEC measurements. The advantage of this method is that commercially available narrow polymer standard can be used which is demonstrated for four series of polymer standards. Knowledge of σad finally enables the application of different correction procedures.
Injection Moulding of Parts with Microstructured Surfaces for Medical Applications
Authors: Gornik Christian
Published: November 2004

m2M‐systems (micro‐to‐Macro) are parts with lateral dimensions of macroscopic scale and structures on the surface in the dimension of microns. The microstructure on the surface has a specific function depending on the intended purpose of the parts. With the use of m2M‐systems new methods of medical diagnostics are possible. Nowadays for the realisation of such parts mainly planar methods known from microelectronics and their standard materials silicon and glass are used. An alternative is to make m2M‐systems by injection moulding of plastics which lowers the manufacturing costs. In order to get an acceptable replication of the microstructure the use of special moulding techniques is necessary. The results of investigations in the variotherm moulding process and the requirements for the injection moulding machine are described in this paper.
New Capabilities of Rheology for Polymer Compound Industry
Authors: Locati Giancarlo , Valle Andrea
Published: November 2004

Recent developments in testing equipment are enabling a better exploitation of rheology as a tool for polymer compound industry.

After a short review of the novelties of recent equipment, some selected possibilities are shown in this paper, ranging from improved quality control of incoming and outcoming products, to recycling management, masterbatches characterization, and evaluation of dispersion effects on filled materials.