bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary Results From a Phase II Trial of Conformal Radiation Therapy and Evaluation of Radiation-Related CNS Effects for Pediatric Patients With Localized Ependymoma
Authors: Merchant Thomas E. , Mulhern Raymond K. , Krasin Matthew J. , Kun Larry E. , Williams Tani , Li Chenghong , Xiong Xiaoping , Khan Raja B. , Lustig Robert H. , Boop Frederick A. , Sanford Robert A.
Published: July 2004

Purpose

We conducted a phase II trial of conformal radiation therapy (CRT) for localized childhood ependymoma to determine whether the irradiated volume could be reduced to decrease CNS-related side effects without diminishing the rate of disease control.

Patients and Methods

Between July 1997 and January 2003, 88 pediatric patients (median age, 2.85 ± 4.5 years) received CRT in which doses (59.4 Gy to 73 patients or 54.0 Gy after gross-total resection to 15 patients younger than 18 months) were administered to the gross tumor volume and a margin of 10 mm. Patients were categorized according to extent of resection (underwent gross total resection, n = 74; near-total resection, n = 6; subtotal resection, n = 8), prior chemotherapy (n = 16), tumor grade (anaplastic, n = 35), and tumor location (infratentorial, n = 68). An age-appropriate neurocognitive battery was administered before and serially after CRT.

Results

The median length of follow-up was 38.2 months (± 16.4 months); the 3-year progression-free survival estimate was 74.7% ± 5.7%. Local failure occurred in eight patients, distant failure in eight patients, and both in four patients. The cumulative incidence of local failure as a component of failure at 3 years was 14.8% ± 4.0%. Mean scores on all neurocognitive outcomes were stable and within normal limits, with more than half the cohort tested at or beyond 24 months.

Conclusion

Limited-volume irradiation achieves high rates of disease control in pediatric patients with ependymoma and results in stable neurocognitive outcomes.
Expression and the Biological Activities of Insulin-Like Growth Factor-Binding Protein Related Protein 1 in Rat Uterus during the Periimplantation Period
Authors: Tamura Kazuhiro , Hara Takahiko , Kutsukake Masahiko , Iwatsuki Ken , Yanagida Mayuko , Yoshie Mikihiro , Kogo Hiroshi
Published: July 2004

IGF binding protein-related protein 1 (IGFBP-rP1) is highly expressed in the rat uterus around the time of implantation. In the present study, we determined the periimplantation localization of IGFBP-rP1 mRNA and assessed the effects of recombinant IGFBP-rP1 on the proliferative and prostacyclin (PGI2)-producing abilities of cultured endometrial cells early in pregnancy. IGFBP-rP1 mRNA was detected at high levels in endometrial stromal cells close to the smooth muscle of interimplantation sites around the time of implantation but absent from decidual zones surrounding the embryo. Differential uterine IGFBP-rP1 expression was also recognized in the delayed implanting pregnant model, but the level of mRNA decreased as decidual tissues formed in the decidualization model. Recombinant IGFBP-rP1 inhibited the proliferation of endometrial stromal cells in vitro and arrested them in the G1 phase of the cell cycle. Furthermore, IGFBP-rP1 significantly stimulated PGI2 synthesis and cyclooxygenase II mRNA expression in myometrial cells, both of which are essential molecules for successful implantation. These data suggest that IGFBP-rP1 is an implantation-associated protein and that it modulates the proliferation of rat uterine cells and their production of PGI2 during the periimplantation period.
Influence of Diabetes on the Exacerbation of an Inflammatory Response in Cardiovascular Tissue
Authors: Lu Huafei , Raptis Markos , Black Elena , Stan Maria , Amar Salomon , Graves Dana T.
Published: July 2004

Coronary artery disease results from an inflammatory process in blood vessels of afflicted individuals. This process is accelerated with diabetes for reasons that are largely unknown. Recent evidence indicates that infection at sites remote from the heart leads to bacteremia and endotoxemia, thereby stimulating systemic inflammation, which represents an important risk factor for atherosclerosis. We examined the inflammatory response of the heart/aorta of diabetic db/db mice that develop type II diabetes. Subcutaneous inoculation of lipopolysaccharide was used to mimic a local infection. This stimulated an up-regulation of adhesion molecules, cytokines, and chemokines via an endotoxemia that was significantly more rapid and more pronounced in the diabetic compared with normal mice. The 13- to 30-fold induction of key proinflammatory molecules in the heart/aorta of diabetic mice even exceeded that at the site of inoculation. Given that infection, bacteremia, and endotoxemia are relatively frequent events in humans, these results identify a putative mechanism for increased cardiovascular heart disease in diabetes.
Cooperative Activation of Lipolysis by Protein Kinase A and Protein Kinase C Pathways in 3T3-L1 Adipocytes
Authors: Fricke Katrin , Heitland Aleksandra , Maronde Erik
Published: July 2004

In the present study, we investigate the coherence of signaling pathways leading to lipolysis in 3T3-L1 adipocytes. We observe two linear signaling pathways: one well known, acting via cAMP and protein kinase A (PKA) activation, and a second one induced by phorbol 12-myristate 13-acetate treatment involving protein kinase C (PKC) and MAPK. We demonstrate that both the PKA regulatory subunits RIα and RIIβ are expressed in 3T3-L1 adipocytes and are responsible for the lipolytic effect mediated via the cAMP/PKA pathway. Inhibition of the PKA pathway by the selective PKA inhibitor Rp-8-CPT-cAMPS does not impair lipolysis induced by PKC activation, and neither PD98059 nor U0126, as known MAPK kinase inhibitors, changes the level of glycerol release caused by PKA activation, indicating no cross-talk between these two pathways when only one is activated. However, when both are activated, they act synergistically on glycerol release. Additional experiments focusing on this synergy show no involvement of MAPK phosphorylation and cAMP formation. Phosphorylation of hormone-sensitive lipase is similar upon stimulation of either pathway, but we demonstrate a difference in the ability of both PKA and the PKC pathway activation to phosphorylate perilipin, which in turn may be an explanation for the different maximal lipolytic effect of both pathways.
Sense‐making in the wake of September 11th: A network analysis of lay understandings
Authors: Reser Joseph P. , Muncer Steven
Published: July 2004

The objective of this research was to document and explore British university students' immediate understanding of the events of September 11th. A network analysis of lay causal perceptions procedure was employed to capture the social perceptions and sense‐making of respondents at a time when they and the world struggled to impose meaning and coherence on the events. The study also examined the possible effects of ‘belief in a just world’ and ‘right‐wing authoritarianism’ on the pattern of perceived causes. The results suggest that most participants perceive cultural and religious differences, the history of conflict in the Middle East, unfairness and prejudice as being the distal causes of the individual agent's emotions and actions. There is also some evidence that right‐wing authoritarianism and belief in a just world have an interactive effect on the strength of the perceived link between some of these causes.
Information about the logical structure of a category affects generalization
Authors: Pothos Emmanuel M. , Chater Nick , Stewart Andrew J.
Published: July 2004

This paper considers whether information about the logical structure of a category affects how people generalize. We carried out three experiments with the following structure: participants were first presented with a set of training items, and were subsequently asked to decide whether new items belonged to the same category as the training items. Each experiment had two conditions that differed only in terms of the category label provided for the training items; different category labels conveyed different information about the logical structure of the category to which the training items were supposed to belong. In all cases, participants' generalization was greatly affected by such information. Our results suggest that people make the default assumption that category labels correspond to groupings of highly similar objects.
Changing levels of numeracy and other core mathematical skills among psychology undergraduates between 1992 and 2002
Authors: Mulhern Gerry , Wylie Judith
Published: July 2004

Teaching statistics and research methods to psychology undergraduates is a major pedagogic challenge. Knowledge of students' conceptual problems in mathematics is important in the current climate of widening access, a burgeoning interest in psychology, and fears about declining standards of numeracy and other quantitative skills. This study compared the mathematical knowledge of two cohorts of undergraduates who entered psychology a decade apart — one in 1992, the other in 2002. Six broadly defined components of mathematical thinking relevant to the teaching of statistics in psychology were examined –calculation, algebraic reasoning, graphical interpretation, proportionality and ratio, probability and sampling, andestimation. Both cohorts were also compared with a 1984 cohort on a subset of items reported in a study by Greer and Semrau (1984). Results revealed highly significant differences between the two cohorts on all six components, with 1992 students outperforming their 2002 counterparts. Males were also found to perform significantly better than females on a majority of components. Level of qualification in mathematics was found to predict overall performance. Comparison with Greer and Semrau's (1984) sample revealed an alarming decline in performance across the two decades on a selection of test items.
Preparation of Gold Nanoparticle–DNA Conjugates
Authors: Taton T. Andrew
Published: July 2004

This unit describes the preparation of conjugates between nanometer‐scale gold particles and synthetic oligonucleotides. Oligonucleotide‐functionalized gold nanoparticles are finding increased use in both the construction of complex, tailored nanostructures and the optimization of DNA sequence analysis. The protocols in this unit outline the synthesis, purification, and characterization of nanoparticle‐DNA conjugates for applications in nanotechnology and biotechnology. Separate procedures are presented for nanoparticles functionalized with just one or a few oligonucleotide strands and for nanoparticles functionalized with a dense layer of oligonucleotide strands. The different physical and chemical properties of these two types of conjugates are discussed, as are their stability and utility in different environments.
Vibration control ability of multilayered composite material made of epoxy beam and polyurethane copolymer with shape memory effect
Authors: Heung Yang Jae , Chul Chun Byoung , Chung Yong‐Chan , Whan Cho Jae , Gyoo Cho Bong
Published: July 2004

Sandwich‐type layered composite material was prepared with epoxy beam and polyurethane copolymer that was synthesized from 4,4‐methylene bis (phenylisocyanate), poly(tetramethyleneglycol), and 1,4‐butanediol as a chain extender. As for the polyurethane, shape recovery was improved with higher content of hard segment, and the highest damping effect as judged by tan δ was observed at 30–35% hard segment. The composite material had better impact strength and higher tan δ than epoxy beam alone, but the superiority became less as more hard segment was incorporated. The interfacial binding force between polyurethane and the epoxy beam also decreased in proportion to the hard segment content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 302–307, 2004
A mucoadhesive polymer prepared by template polymerization of acrylic acid in the presence of poly(vinyl alcohol) for mucosal drug delivery
Authors: Oh Jung‐Min , Cho Chong‐Su , Choi Hoo‐Kyun
Published: July 2004

The interpolymer complexes composed of PVA and PAA were prepared by template polymerization of acrylic acid in the presence of PVA with different molecular weights and degrees of saponification. The carbonyl absorption band of the PAA in the PAA/PVA interpolymer complexes was shifted to a lower wavenumber due to H‐bonding between the carboxyl group of PAA and the hydroxyl group of PVA. The swelling ratio and the degree of dissolution of the PVA/PAA interpolymer complexes were dependent on the pH of the medium, the molecular weight, and the degree of saponification of the PVA. The release rate of a model drug, lidocaine, from the complexes decreased with increasing degree of saponification of the PVA due to the lower swelling degree of the complex. The adhesive force of the PVA/PAA interpolymer complexes with a plastic plate (poly propylene) was stronger than that of the commercial Carbopol 971P. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 327–331, 2004
Effects of systematic peripheral group deuteration on the low‐frequency resonance Raman spectra of myoglobin derivatives
Authors: Mak Piotr J. , Podstawka Edyta , Kincaid James R. , Proniewicz Leonard M.
Published: July 2004

Resonance Raman spectra are reported for a series of systematically deuterated analogues of myoglobin in its deoxy state as well as for its CO and O2 adducts. Specifically, the myoglobin samples studied are those that have been reconstituted with deuterated protoheme analogues. These include the methine deuterated, protoheme‐d4; analogue bearing C2H3 groups at the 1, 3, 5, and 8 positions, protoheme‐d12; the species bearing C2H3 groups at the 1 and 3 positions only, 1,3‐protoheme‐d6; and the species bearing C2H3 groups at the 5 and 8 positions only, 5,8‐protoheme‐d6. While the results are generally consistent with previously reported data for synthetic metalloporphyrin models and previous studies of labeled heme proteins, the high‐quality low‐frequency RR data reported here reveal several important aspects of these low‐frequency modes. Of special interest is the fact that, using the two d6‐protoheme analogues, it is shown that certain modes are apparently localized on particular pyrrole rings, while others are localized on different rings; i.e., several of these low‐frequency modes are localized on one side of the heme. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Hippocampus 5‐HT1A‐receptors attenuate cocaine‐induced hyperlocomotion and the increase in hippocampal but not nucleus accumbens 5‐HT
Authors: Müller Christian P. , Thönnessen Heike , Barros Marilia , Tomaz Carlos , Carey Robert J. , Huston Joseph P.
Published: July 2004

Cocaine induces an increase in hippocampal and nucleus accumbens (Nac) serotonin (5‐HT) concentration parallel to locomotor activation. Both effects can be modulated by systemic 5‐HT1A‐receptor agonism/antagonism. Given the contribution of the hippocampus to spontaneous behavioral activity, these observations suggest a role for hippocampal 5‐HT as well in the modulation of cocaine effects on behavior. To determine the role of hippocampal 5‐HT1A‐receptors in cocaine effects on behavior and hippocampal 5‐HT release, we used in vivo microdialysis in freely moving rats. The 5‐HT1A‐receptor agonist, 8‐OH‐DPAT (0, 0.1, 1 and 10 μM), was applied locally into the hippocampus by reversed dialysis followed by a cocaine (10 mg/kg) or saline i.p. injection. The hippocampal 5‐HT1A‐receptor activation attenuated cocaine‐induced hyperlocomotion and rearing behavior dose‐dependently. Parallel to that, the cocaine‐induced 5‐HT increase was attenuated dose‐dependently in the hippocampus but was left unaffected in the Nac. The intra‐hippocampal application of 8‐OH‐DPAT affected neither behavioral activity nor 5‐HT concentration in the hippocampus and in the Nac. In accord with these findings, hippocampal 5‐HT1A‐receptors may not be directly involved in the regulation of spontaneous behavior or basal 5‐HT concentration in the hippocampus and Nac. However, the results indicate an inhibitory role of hippocampal 5‐HT1A‐receptors in cocaine‐induced hyperactivity and in the 5‐HT increase evoked by cocaine in the hippocampus but not in the Nac. © 2004 Wiley‐Liss, Inc.
Prostate carcinoma and green tea: PSA‐triggered basement membrane degradation and MMP‐2 activation are inhibited by (−)epigallocatechin‐3‐gallate
Authors: Pezzato Elga , Sartor Luigi , Dell'Aica Isabella , Dittadi Ruggero , Gion Massimo , Belluco Claudio , Lise Mario , Garbisa Spiridione
Published: July 2004

Prostate‐specific antigen (PSA) is a serine‐protease that, in addition to cleaving semenogelins in the seminal coagulum, is able to cleave extracellular matrix glycoproteins, thereby affecting cell migration and metastasis. We here report some new activities of PSA that deserve careful consideration in the cancer context: degradation of gelatin, degradation of type IV collagen in reconstituted basement membrane (Matrigel) and activation of progelatinase A (MMP‐2), but not pro‐MMP‐9, in a cell‐free system. Since consumption of green tea has been reported to lower the risk of prostate cancer, we investigated the effects of the major flavanol of green tea, (−)epigallocatechin‐3‐gallate (EGCG), on expression and activity of PSA by prostate carcinoma cells. In addition to restraint of PSA expression, EGCG was found to inhibit in a dose‐dependent manner all the above PSA activities, at concentrations lower than the cytotoxic serine‐protease inhibitor PMSF and close to levels measured in the serum following ingestion of green tea. The activity of PSA was suppressed also by the elastase released by the inflammatory leukocytes. These results highlight new PSA activities, suggest gelatin zymography as a new convenient assay for PSA, propose EGCG as natural inhibitor of prostate carcinoma aggressiveness, but also stimulate further investigation on the role of prostatic inflammation. © 2004 Wiley‐Liss, Inc.
Sun exposure may protect against non‐Hodgkin lymphoma: A case‐control study
Authors: Hughes Ann Maree , Armstrong Bruce K. , Vajdic Claire M. , Turner Jennifer , Grulich Andrew E. , Fritschi Lin , Milliken Sam , Kaldor John , Benke Geza , Kricker Anne
Published: July 2004

Ultraviolet radiation is a hypothesised risk factor for non‐Hodgkin lymphoma (NHL) but no epidemiological study has examined this association using direct measures of sun exposure in individuals. Adults aged 20–74 years living in NSW and ACT, Australia, were the study population. Cases (704 of 829 invited to take part, 85%) were diagnosed January 2000 to August 2001. Controls (694 of 1,136 invited to take part, 61%) were randomly selected from state electoral rolls and frequency‐matched to cases by age, sex and state of residence. A self‐administered questionnaire and telephone interview measured outdoor hours on working and nonworking days and vacations at 10, 20, 30, 40, 50 and 60 years of age. Logistic regression models of NHL and sun exposure contained the 3 matching variables, ethnicity and sun sensitivity measures as covariates. Contrary to expectations, risk of NHL fell with increasing reported sun exposure hours. Relative to 1.0 for the lowest quarter of total sun exposure hours, the odds ratios (ORs) for successively higher quarters were 0.72 (95% CI 0.53–0.98), 0.66 (0.48–0.91) and 0.65 (0.46–0.91) (ptrend=0.01). The association of sun exposure on nonworking days with NHL was stronger; OR for highest quarter 0.47 (0.34–0.66) (ptrend=0.0001). Risk also fell with sun exposure on vacations; OR for highest quarter 0.60 (0.43–0.85) (ptrend=0.003). These associations appeared strongest in women and in childhood. There was little evident trend in risk with exposure on working day. Our results provide strong statistical evidence for an inverse association between sun exposure and NHL. Increasing evidence that vitamin D may protect against cancer makes UV‐mediated synthesis of vitamin D a plausible mechanism whereby sun exposure might protect against NHL. © 2004 Wiley‐Liss, Inc.
Interactions between rat colon carcinoma cells and Kupffer cells during the onset of hepatic metastasis
Authors: Timmers Maarten , Vekemans Katrien , Vermijlen David , Asosingh Kewal , Kuppen Peter , Bouwens Luc , Wisse Eddie , Braet Filip
Published: July 2004

Liver sinusoids harbor populations of 2 important types of immunocompetent cells, Kupffer cells (KCs) and natural killer (NK) cells, which are thought to play an important role in controlling hepatic metastasis in the first 24 hr upon arrival of the tumor cells in the liver. We studied the early interaction of KCs, NK and CC531s colon carcinoma cells in a syngeneic rat model by confocal laser scanning microscopy. Results showed a minority of KCs (19% periportal and 7% pericentral) involved in the interaction with 94% of tumor cells and effecting the phagocytosis of 92% of them. NK cell depletion decreased the phagocytosis of tumor cells by KCs by 33% over a period of 24 hr, leaving 35% of the cancer cells free, as compared to 6% in NK‐positive rats. Surviving cancer cells were primarily located close to the Glisson capsule, suggesting that metastasis would initiate from this region. © 2004 Wiley‐Liss, Inc.
Deregulation of Stat5 expression and activation causes mammary tumors in transgenic mice
Authors: Iavnilovitch Elena , Cardiff Robert D. , Groner Bernd , Barash Itamar
Published: July 2004

Members of the signal transducers and activators of transcription (Stat) family regulate essential cellular growth and survival functions in normal cells and have also been implicated in tumorigenesis. We have studied the potential role of Stat5 in mammary tumorigenesis by targeting Stat5 variants to the mammary gland of transgenic mice using regulatory sequences of the β‐lactoglobulin gene. Mammary‐directed expression of the wild‐type Stat5, constitutively activated Stat5 and carboxyl‐terminally truncated dominant negative Stat5 forms resulted in mammary tumors with incidence rates of up to 22% and latency periods of 8–12 months. Undifferentiated carcinomas most frequently occurred in mice expressing the carboxyl‐terminally truncated Stat5. The more differentiated papillary and micropapillary adenocarcinomas were primarily found in mice overexpressing the native and constitutively active transgenes. Higher levels of translation initiation factor 4E (eIF4E) and cyclin D1 expression but lower levels of activated Stat3 were found in tumors of mice expressing the constitutively active Stat5 when compared to mice expressing the wild‐type or truncated forms. A higher expression of the estrogen receptor (ERα) was observed in carcinomas compared to other phenotypes. The ability of both forms of Stat5, the transactivating form and the dominant negative form, to participate in oncogenesis indicates that there is more than one mechanism by which Stat5 contributes to this process. The transactivation function of Stat5 is involved in the determination of tumors with a more differentiated phenotype. © 2004 Wiley‐Liss, Inc.
Promoter hypermethylation of tumor‐related genes in the progression of colorectal neoplasia
Authors: Bai Alfa H.C. , Tong Joanna H.M. , To Ka‐Fai , Chan Michael W.Y. , Man Ellen P.S. , Lo Kwok‐Wai , Lee Janet F.Y. , Sung Joseph J.Y. , Leung Wai K.
Published: July 2004

Gene promoter hypermethylation is increasingly recognized to play an important role in cancer development through silencing of gene transcription. This study determined the methylation profiles of primary colorectal cancers and adenomas to elucidate the role of epigenetic changes in different stages of colorectal carcinogenesis. We examined the methylation profiles of 47 sporadic colorectal cancers, 36 colonic adenomas from patients without cancer and 34 colonic biopsies from patients without colonic lesions. Paired adjacent dysplasia tissues obtained from 17 cancer patients were also examined. Promoter hypermethylation in 10 tumor‐related genes (APC, ATM, GSTP1, HLTF, MGMT, hMLH1, p14, p15, SOCS‐1 and TIMP‐3) were studied by methylation‐specific PCR. Promoter hypermethylation was frequently detected in more than 40% of colonic cancers and adenomas in APC, ATM, HLTF, MGMT and hMLH1 genes (p < 0.0001 vs. normal). While low level of methylation was detected in p14, p15 and TIMP‐3, there was no methylation detected in GSTP1 and SOCS‐1. The frequencies of methylation were comparable between tumors and adenomas, and advanced and nonadvanced adenoma. In contrast, K‐ras mutation was only detected in advanced adenomas and cancers. Concurrent methylation in ≥ 3 genes was found in 66.7% adenomas and 68.1% cancers but not in normal colonic tissues. Methylation was associated with reduced protein expressions in colorectal adenomas and cancers. Moreover, methylation in ATM was more common in older cancer patients (p = 0.002), but there was no significant association between promoter hypermethylation and other clinicopathologic characteristics of cancer. Our study demonstrated the early and specific involvement of promoter hypermethylation in the colorectal adenoma‐carcinoma sequence. © 2004 Wiley‐Liss, Inc.
Downregulation of rheumatoid arthritis‐related antigen RA‐A47 (HSP47/colligin‐2) in chondrocytic cell lines induces apoptosis and cell‐surface expression of RA‐A47 in association with CD9
Authors: Hattori Takako , von der Mark Klaus , Kawaki Harumi , Yutani Yasutaka , Kubota Satoshi , Nakanishi Tohru , Eberspaecher Heidi , de Crombrugghe Benoit , Takigawa Masaharu
Published: July 2004

Previously, we showed that gene expression of the rheumatoid arthritis‐related antigen RA‐A47, which is identical to human heat shock protein (HSP)47, was downregulated in chondrocytes by inflammatory cytokines such as TNFα. Associated with this phenomenon, RA‐A47 appeared on the cell surface concomitant with upregulation of metabolic factors related to cartilage destruction. The upregulation of the metabolic factors could be achieved by downregulation of RA‐A47 expression with ra‐a47‐specific anti‐sense oligonucleotide. Here, we show that the enhanced surface expression of RA‐A47 on a chondrocytic cell line, HCS‐2/8 was also a direct result of RA‐A47 downregulation by ra‐a47 anti‐sense oligonucleotide, independent of the cytokine effects. Moreover, cell‐surface expression of CD9, a β1 integrin‐associated transmembrane protein that is involved in cell adhesion and cell motility events, was enhanced in the ra‐a47 anti‐sense oligonucleotide‐treated cells. The CD9 was colocalized with RA‐A47 on the cell surface, where it may have affected integrin signaling. Furthermore, Annexin‐V binding to the cell surface and the level of a number of apoptosis‐related genes including caspase‐9 were increased after ra‐a47 anti‐sense oligonucleotide treatment, suggesting that enhanced surface expression of RA‐A47 and CD9 may be initiating apoptosis. Differential screening using a cDNA gene array showed induction of metallothionein‐III and chemokine receptor CXCR4 and of factors of the Notch signaling pathway by the anti‐sense treatment, but not by TNFα. Thus, here we show for the first time an alternative mechanism of inducing apoptosis by downregulating molecular chaperones, independent of the action of TNFα. The surface‐exposed RA‐A47 may induce autoantibodies and inflammatory reactions in autoimmune disease situations such as rheumatoid arthritis. © 2005 Wiley‐Liss, Inc.
Contribution of mass spectrometry to the study of the Maillard reaction in food
Authors: Fay Laurent B. , Brevard Hugues
Published: July 2004

The Maillard reaction or non‐enzymatic browning corresponds to a set of reactions occurring between amines and carbonyl compounds, especially reducing sugars. The Maillard reaction is known to occur in heated, dried, or stored foods and in vivo in mammalian organisms. In food, the Maillard reaction is responsible for changes in colour, flavor, and nutritive value but also for the formation of stabilizing and mutagenic compounds. Because of the complexity of the Maillard reaction, mass spectrometry, coupled or not to separation techniques, is a key tool in this research area and we will review in this article the contribution of mass spectrometry to the understanding of this reaction. Different steps of Maillard reaction will be described and the importance and the role played by mass spectrometry will be highlighted. In addition, different approaches to investigate the Maillard reaction from the formation of Amadori products (early Maillard reaction product) to the flavor and melanoidin production will also be covered. © 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:487–507, 2005
Parallel‐coupled microstrip bandpass filters with a wide stopband using spur lines
Authors: Sung Y. , Ahn C. S. , Kim Y.‐S.
Published: July 2004

In this paper, we propose a novel parallel‐coupled microstrip bandpass filter with a wide stopband. The proposed bandpass filter with spur lines provides a deep and wide stopband because spur lines can provide deep stopband characteristics in some frequency bands. Also, the experimental results show that the transmission coefficients of the proposed filter are lower than −50 dB around the 2nd‐ and 3rd‐harmonic frequencies. This operation can be obtained without increasing its size while the other features are not degraded. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 9–11, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20359
Analytical expression for a composite right/left‐handed transmission line based on the Mittag‐Leffler series expansion
Authors: Fujishige Timothy , Caloz Christophe , Itoh Tatsuo
Published: July 2004

An analytical expression for the admittance matrix of a lossy composite right/left‐handed transmission line (CRLH‐TL) based on the Mittag–Leffler series expansion is presented. This expression can be used to model a periodic CRLH‐TL with an expansion truncated to a small number of terms over a prescribed frequency range, which provides the transient response of the line in a faster and more efficient manner than full lumped‐element analysis. A numerical study comparing the admittance parameters calculated using the ideal‐TL infinitesimal model, the lumped‐element model, and the Mittag–Leffler expansion (MLE) is conducted. The transient responses of a CRLH‐TL using the lumped‐element model and the MLE are compared. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 26–29, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20364
Modeling of photonic band gap waveguide couplers
Authors: Nagpal Yogita , Sinha R.K.
Published: July 2004

The co‐directional coupling between two photonic band gap (PBG) waveguides is studied. The designs of PBG waveguide couplers with different lattice arrangements are presented and their coupling characteristics are studied. Further, their application in the design of ultra‐short optical multiplexer de‐multiplexers (MUX‐DEMUXs) has been investigated. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 47–50, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20371
A novel wideband coplanar‐fed monopole antenna
Authors: Wang Wei , Zhong S. S. , Chen Sheng‐Bing
Published: July 2004

A new T‐shaped monopole antenna with a CPW feed line is presented. The theoretical analysis is based on the finite‐difference time‐domain (FDTD) method. The novel antenna is designed, fabricated, and then measured. The measured results, which agree with the numerical calculations very well, are given. The measured bandwidth of the antenna is approximately 116% for VSWR ≤ 2.0. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 50–52, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20372
Tensor product derivative matching for wave propagation in inhomogeneous media
Authors: Zhao Shan , Wei G. W.
Published: July 2004

We propose a tensor product derivative matching (TPDM) method to restore the accuracy of high‐order finite difference time‐domain (FDTD) schemes of computational electromagnetics (CEM) with material interfaces in two spatial dimensions (2D). By making use of fictitious points, the TPDM method locally enforces the physical‐jump conditions at material interfaces in a preprocessing stage to arbitrarily high orders of accuracy in principle, based on a structured grid. The proposed method encompasses a variety of schemes of different orders in a single code. In fact, numerical orders from 2 to near 16 are confirmed in the present study. To the best of our knowledge, such high orders have not been reported in the literature for CEM problems involving material interfaces. The limitation and applicability of the present scheme are also analyzed in detail. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 69–77, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20378
Nonsplit dual‐stage EDFA operating in the C‐ plus L‐band
Authors: Sinivasagam V. , Singh R. D. , Abushagur M. A. G. , Dimyati K.
Published: July 2004

The feasibility of a dual‐stage erbium‐doped fiber amplifier (EDFA) design for operation in both the C‐band and the L‐band is studied. The design is comprised of nonsplit single‐pass amplification at both bands, thus eliminating the need for band multiplexing and demultiplexing in an individual band‐amplification design. The results show that the amplifier provides continuous homogeneous gain ranging from 1530 to 1605 nm with an average gain of 19.7 dB at −30‐dBm input signal power. A minimum gain variation of 9.5 dB was achieved for this entire range, which includes the standard 1530‐nm‐region gain peak in a silica‐based EDF and without the assistance of any gain‐flattening devices. The noise figure was below 7.4 dB for the entire C‐ plus L‐band region for a minimum of 5.3 dB at 1570 nm, with signal power of −30 dBm. This C‐ plus L‐band EDFA provides an average output power of 6.1 dBm at −10 dBm input signal power. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 82–84, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20381
A GaInP/GaAs HBT micromixer for 2.4/5.2/5.7‐GHz multiband WLAN applications
Authors: Wang C. Y. , Lu S. S. , Meng C. C. , Lin Y. S.
Published: July 2004

A GaInP/GaAs HBT micromixer for 2.4/5.2/5.7‐GHz multiband WLAN applications is demonstrated. Our experimental results show that the input return loss |S11| is below −25 dB from DC to 10 GHz with power‐conversion gains of 11.7, 11.9, and 11.5 dB at frequencies of 2.4, 5.2, and 5.7 GHz, respectively. The wideband matching characteristic makes the micromixer very suitable for multiband applications. Input P1dB is −4 dBm and IIP3 is 2.36 dBm. Port‐to‐port isolation is also quite satisfactory. In addition, the single‐to‐differential input stage in the Gilbert micromixer eliminates the need for common‐mode rejection. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 87–89, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20383
A posteriori error estimation and adaptive computation of viscoelastic fluid flow
Authors: Ervin Vincent J. , Ntasin Louis N.
Published: July 2004

In this article, we develop a posteriori error estimates for finite element (FE) approximations of viscoelastic fluid flows governed by differential constitutive laws of Giesekus and Oldroyd‐B type. We use the general framework developed by Verfürth for constructing residual based a posteriori error estimates for nonlinear equations. Numerical experiments using adaptive computations demonstrating the effectiveness of these error estimates are then presented for three examples. The first two examples are problems with known solutions and the third example is, a benchmark problem, the channel flow with a cylindrical obstacle problem. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005
Thermal decomposition, combustion and fire‐retardancy of polyurethanes—a review of the recent literature
Authors: Levchik Sergei V , Weil Edward D
Published: July 2004

An overview is presented of the literature on thermal decomposition, combustion and fire‐retardancy of polyurethane (PU) elastomers, PU‐based coatings, rigid and flexible PU foams. A brief overview of the structure of PU polymeric networks is helpful for a better understanding of the thermal decomposition and combustion phenomena. Literature sources were mostly taken from the publications of 1995 and later; however, for a basic description of the structural and thermal decomposition principles, older publication have also been cited. New developments in the efficient halogen‐containing additives and reactive copolymers are described. However, major progress in the area of flame‐retardant PUs in recent years is found in the field of phosphorus‐ or silicon‐containing products, especially reactive ones. Inorganic additives remain of great interest, especially in PU‐based intumescent coatings. Copyright © 2004 Society of Chemical Industry
Modification of the air–water interface by a chitosan adsorption process. Effect on an amphiphilic polymer monolayer
Authors: Gargallo Ligia , Leiva Angel , Urzúa Marcela , Alegría Luz , Miranda Beatriz , Radić Deodato
Published: July 2004

Monolayer formation by poly[(maleic anhydride)‐alt‐(stearyl methacrylate)] (MA‐alt‐StM) on aqueous subphases, with and without chitosan, was studied by the Langmuir technique. Chitosan (CS) modified considerably the shape of the MA‐alt‐StM isotherms on water. To explain this behavior, the surface activity properties of chitosan at the air–solution interface were studied. The variations of the interfacial tension, γint, with chitosan concentration and temperature, were also determined. The results were discussed in terms of the modification of the air–water interface owing to the presence of chitosan in the subphase and the surface activity. It was found that the standard free energy of adsorption, $\Delta\ G_{{\rm ads}}^{0}$, values were dependent on the degree of acetylation (DA) over the DA range being studied. Copyright © 2004 Society of Chemical Industry
Thermoplastic elastomers from rubber and recycled polyethylene: chemical reactions at interphases for property enhancement
Authors: Grigoryeva Olga , Fainleib Alexander , Starostenko Olga , Tolstov Alexander , Brostow Witold
Published: July 2004

Recycled low density polyethylene (R‐LDPE) has been reactively compatibilized with butadiene rubber (BR) by using small additions of reactive polyethylene copolymers and reactive BRs to produce thermoplastic elastomers (TPEs). TPEs were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), rheology measurements, wide‐angle X‐ray scattering (WAXS) and mechanical testing. WAXS results show that the presence of BR and reactive modifiers does not completely prevent the crystallization of R‐LDPE during the TPE formation. Depression of the melting point has been found in all cases. Also in all cases, compatibility is provided by formation of interfacial layers. The best mechanical characteristics are obtained for R‐LDPE + BR blends compatibilized with poly(ethylene‐co‐acrylic acid) (PE‐co‐AA) and polybutadiene terminated with isocyanate groups (PB‐NCO) for PB‐NCO = 7.5 wt% per PB and COOH/NCO ratio = 1/1. The stress at break and elongation at break are respectively improved by 31 % and 63 %. The PB‐NCO modifier participates in co‐vulcanization with BR in the rubber phase and reacts at the interface with the PE‐co‐AA dissolved in the polyolefin phase. As a result, the amorphous phase of R‐LDPE is dissolved by the rubber phase and a morphology with dual phase continuity is formed, assuring an improvement of mechanical properties of TPEs. Copyright © 2004 Society of Chemical Industry
The effect of 60Co γ‐rays on the crystal structure, melting and crystallization behavior of poly(butylene succinate)
Authors: Song Jianbin , Ren Minqiao , Song Chunlei , Wang Shuyun , Zhang Hongfang , Mo Zhishen
Published: July 2004

The results obtained for poly(butylene succinate) (PBS) after 60Co γ‐ray irradiation, studied by wide‐angle X‐ray diffraction (WAXD), differential scanning calorimeter (DSC) and polarizing optical microscopy (POM), revealed that the degree of crystallinity, melting temperature and enthalpy decreased with increasing irradiation dose, but that the crystal structure of PBS did not vary when compared to non‐irradiated PBS. By using Scherrer equation, small changes occurred in the crystal sizes of L020, L110 and L111. The spherulitic morphology of PBS was strongly dependent on irradiation dose and changed significantly at higher irradiation dosages. The crystallization kinetics of PBS indicated that the Avrami exponent (n) for irradiated PBS was reduced to 2.3, when compared to non‐irradiated PBS (3.3). Copyright © 2004 Society of Chemical Industry
Green composites of organic materials and recycled post‐consumer polyethylene
Authors: La Mantia FP , Dintcheva N Tzankova , Morreale M , Vaca‐Garcia C
Published: July 2004

Addition of organic fillers to post‐consumer recycled plastics can give rise to several advantages. First of all, the cost of these fillers is usually very low, the organic fillers are biodegradable contributing to an improved environmental impact and, last but not least, some mechanical and thermomechanical properties can be enhanced. Organic fillers are not widely used in the plastic industry although their use is increasing. Bad dispersion into the polymer matrix at high‐level content and poor adhesion with the matrix are the more important obstacles to this approach. In this work various organic fillers have been used with a post‐consumer plastic material originating from films for greenhouses. The properties of these green composites have been compared with those of materials filled with a conventional inorganic filler. The organic fillers cause slightly worse processability, due to an increase of viscosity, an enhancement of the rigidity and of the thermomechanical resistance similar to that measured for the inorganic filler, while a reduction of the impact strength is observed. Copyright © 2004 Society of Chemical Industry
Counterintuitive influence of microscopic chirality on helical order in polymers
Authors: Cheon Kap Soo , Selinger Jonathan V. , Green Mark M.
Published: July 2004

Studies of copolymers of chiral and achiral units forming a helical array correlate to statistical physical predictions of the influence of the chiral units on the helical sense taken by the array. In the absence of conflict among the chiral units for helical sense control, the sergeants and soldiers experiment, a larger chiral bias leads to increased control. However, when conflict exists among the chiral units for helical sense control, the majority rule experiment, a larger chiral bias leads to decreased control of the helical sense and therefore a smaller optical activity. Changing the achiral units in the majority rule experiment can change the nature of the statistical physics between statistical and thermal randomness. In general, the experiments quantitatively demonstrate that the effect of chirality is not an intrinsic property of the chiral moiety but rather depends on the molecular environment. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and photochemistry of a carotene–porphyrin–fullerene model photosynthetic reaction center
Authors: Kodis Gerdenis , Liddell Paul A. , Moore Ana L. , Moore Thomas A. , Gust Devens
Published: July 2004

A new photosynthetic reaction center mimic consisting of a porphyrin (P) linked to both a fullerene electron acceptor (C60) and a carotenoid secondary electron donor (C) was synthesized and studied in 2‐methyltetrahydrofuran using transient spectroscopic methods. Excitation of the porphyrin is followed by photoinduced electron transfer to the fullerene (τ = 32 ps) to yield C–P·+–C60·−. Electron transfer from the carotene to the porphyrin radical cation (τ = 125 ps) gives a final C·+–P–C60·− state with an overall yield of 0.95. This state decays to give the carotenoid triplet state with a time constant of 57 ns. The molecular triad is highly soluble in organic solvents and readily synthesized. These qualities make the molecule a useful artificial photosynthetic reaction center for a variety of spectroscopic and photochemical investigations. Copyright © 2004 John Wiley & Sons, Ltd.
Conformational analysis of calixarene derivatives substituted at the methylene bridges
Authors: Simaan Samah , Biali Silvio E.
Published: July 2004

The conformation of tetrahydroxycalix[4]arene derivatives substituted at two opposite methylene bridges or at a single bridge by an alkyl or aryl group is reviewed. The cone form with an equatorial substituent is the lowest energy conformation of calixarenes possessing one bridge substituted by an alkyl group, whereas both the axial and equatorial conformers are similarly populated if the substituent is an aryl group. In the cone conformation of calixarenes possessing two opposite bridges substituted in trans fashion by a pair of groups, one group must necessarily be located in an axial position. The steric interactions ensuing from the presence of an axial group destabilize the cone conformation, rendering the 1,2‐alternate form the lowest energy conformation in some derivatives. Copyright © 2004 John Wiley & Sons, Ltd.
How quickly do knotty molecules lose their energy as they grow?
Authors: Dhaliwal Manjinder , Weinberg Noham
Published: July 2004

The results of UFF and AM1 calculations for CNH2N hydrocarbon trefoil knots are reported for the range of N from 12 to 59 and used to discuss stabilities of knots and size‐dependent trends in their structural parameters. Other types of molecular knots, including figure‐eight and five‐crossing knots, were identified on MM3 and UFF potential energy surfaces of C30H60 and C50H100. A simple tubular model of molecular knots is discussed and used to identify the minimum size of a knot that has no excess energy due to its topology. Predictions of the tubular model are consistent with UFF and AM1 results. Copyright © 2004 John Wiley & Sons, Ltd.
A p‐benzyne to m‐benzyne conversion through a 1,2‐shift of a phenyl group. Completion of the benzyne cascade
Authors: Polishchuk Alexei L. , Bartlett Kevin L. , Friedman Lee A. , Jones Maitland
Published: July 2004

Pyrolysis of 1,6‐diphenylhexa‐1,5‐diyne‐cis‐3‐ene at 800–1000°C leads to a mixture of 1‐ and 2‐phenylbiphenylene, along with triphenylene. Formation of the two biphenylenes is taken as strong evidence of the rearrangement of a p‐benzyne into a m‐benzyne through a shift of one of the phenyl groups. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and fluorescence properties of a porphyrin–fullerene molecular wire
Authors: Vail Sean A. , Tomé João P. C. , Krawczuk Paul J. , Dourandin Alex , Shafirovich Vladimir , Cavaleiro José A. S. , Schuster David I.
Published: July 2004

The synthesis and photophysical studies of a butadiyne‐linked porphyrin–C60 dyad (ZnP–C60) 6 are described. This is the first porphyrin–[60]fullerene dyad in which the two chromophores are conjugatively linked through a ‘molecular wire’. The UV–visible absorption spectrum for dyad 6 is slightly red shifted relative to the porphyrin precursor 5 whose fluorescence is all but quenched by the attached C60. Copyright © 2004 John Wiley & Sons, Ltd.
Stabilization of benzene versus oligoacetylenes: not another scale for aromaticity
Authors: Baldridge Kim K. , Siegel Jay S.
Published: July 2004

The energies of a number of oligoacetylenes are compared in a homodesmic reaction with benzene. Assessment of the open vs closed form of a conjugated triene is presented along with a perspective on the pursuit of quantitative scales for ‘aromaticity’. Copyright © 2004 John Wiley & Sons, Ltd.