bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of signal transduction proteins during the differentiation of primary human erythroblasts
Authors: di Giacomo Viviana , Matteucci Alessandro , Stellacci Emilia , Battistini Angela , Di Baldassarre Angela , Capitani Silvano , Alfani Elena , Migliaccio Anna Rita , Cocco Lucio , Migliaccio Giovanni
Published: September 2004

The high number (>108–10) of primary human pro‐erythroblasts (CD36high/CD235alow) obtainable in HEMA culture (Migliaccio et al., ) is exploited here to analyse the expression of proteins implicated in erythropoietin (EPO)‐signalling (STATs, PI‐3K, and PLCs) during the process of erythroid maturation. Human pro‐erythroblasts progressed in 4 days of culture with EPO into basophilic‐ (CD36high/CD235amedium, 24 h), polychromatic‐(CD36high/CD235ahigh, 48 h), and, finally, orthochromatic‐(CD36low/CD235ahigh, 72–96 h) erythroblasts. During this maturation, STAT‐1 was expressed up to the orthochromatic stage, expression of STAT‐5, as well as of its target proteins BclxL and IRF1, remained constant up to 48 h (polychromatic‐erythroblasts) but decreased by 96 h (orthochromatic‐erythroblasts), while that of STAT‐3 decreased constantly from 24 h on and became undetectable by 96 h. Expression of PI‐3K rapidly decreased with differentiation since only 50% of original protein levels were detected by 48 h. On the other hand, among the members of PLC families investigated, PLC β4 was not expressed, PLC β2, δ1, and γ2 were expressed at constant levels throughout the maturation process, while expression of PLC β3 and of PLC γ1 decreased, as PI‐3K, by 24 h and that of PLC β1 was induced by 6 h and became undetectable by 24 h. In conclusion, these data depict the dynamic signalling scenario associated with the maturation of erythroid cells and provide the first indication that members of PLC families (PLC β1, β3, and γ1) might be involved in the control of erythroid differentiation in humans. © 2004 Wiley‐Liss, Inc.
Different involvement for aldolase isoenzymes in kidney glucose metabolism: Aldolase B but not aldolase A colocalizes and forms a complex with FBPase
Authors: Yañez Alejandro J. , Ludwig Heide C. , Bertinat Romina , Spichiger Carlos , Gatica Rodrigo , Berlien Gustavo , Leon Oscar , Brito Monica , Concha Ilona I. , Slebe Juan C.
Published: September 2004

The expression of aldolase A and B isoenzyme transcripts was confirmed by RT‐PCR in rat kidney and their cell distribution was compared with characteristic enzymes of the gluconeogenic and glycolytic metabolic pathway: fructose‐1,6‐bisphosphatase (FBPase), phosphoenol pyruvate carboxykinase (PEPCK), and pyruvate kinase (PK). We detected aldolase A isoenzyme in the thin limb and collecting ducts of the medulla and in the distal tubules and glomerula of the cortex. The same pattern of distribution was found for PK, but not for aldolase B, PEPCK, and FBPase. In addition, co‐localization studies confirmed that aldolase B, FBPase, and PEPCK are expressed in the same proximal cells. This segregated cell distribution of aldolase A and B with key glycolytic and gluconeogenic enzymes, respectively, suggests that these aldolase isoenzymes participate in different metabolic pathways. In order to test if FBPase interacts with aldolase B, FBPase was immobilized on agarose and subjected to binding experiments. The results show that only aldolase B is specifically bound to FBPase and that this interaction was specifically disrupted by 60 μM Fru‐1,6‐P2. These data indicate the presence of a modulated enzyme–enzyme interaction between FBPase and isoenzyme B. They affirm that in kidney, aldolase B specifically participates, along the gluconeogenic pathway and aldolase A in glycolysis. © 2004 Wiley‐Liss, Inc.
Expression of Concern: Neurotensin and EGF induce synergistic stimulation of DNA synthesis by increasing the duration of ERK signaling in ductal pancreatic cancer cells
Authors: Kisfalvi Krisztina , Guha Sushovan , Rozengurt Enrique
Published: September 2004

Neurotensin (NT) and epidermal growth factor (EGF) induced rapid extracellular‐regulated protein kinase (ERK) activation through different signaling pathways in the K‐Ras mutated human pancreatic carcinoma cell lines PANC‐1 and MIA PaCa‐2. NT stimulated ERK activation via a protein kinase C (PKC)‐dependent (but EGF receptor‐independent) pathway in PANC‐1 and MIA PaCa‐2 cells, whereas EGF promoted ERK activation through a PKC‐independent pathway in these cells. Concomitant stimulation of these cells with NT and EGF induced a striking increase in the duration of ERK pathway activation as compared with that obtained in cells treated with each agonist alone. Stimulation with NT + EGF promoted synergistic stimulation of DNA synthesis and anchorage‐independent growth. Addition of the MEK inhibitor U0126, either prior to stimulation with NT + EGF or 2 h after stimulation with NT + EGF prevented the synergistic increase in DNA synthesis and suppressed the sustained phase of ERK activation. Furthermore, treatment with the selective PKC inhibitor GF‐1 converted the sustained ERK activation in response to NT and EGF into a transient signal and also abrogated the synergistic increase in DNA synthesis. Collectively, our results suggest that the sustained phase of ERK signaling mediates the synergistic effects of NT and EGF on DNA synthesis in pancreatic cancer cells. © 2004 Wiley‐Liss, Inc.
Interactions between cardiac cells enhance cardiomyocyte hypertrophy and increase fibroblast proliferation
Authors: Fredj Sandra , Bescond Jocelyn , Louault Claire , Potreau Daniel
Published: September 2004

In cardiac hypertrophy, both excessive enlargement of cardiac myocytes (CMs) and progressive fibrosis are known to occur simultaneously. To investigate the nature of interactions between ventricular CMs and cardiac fibroblasts (CFs) in these conditions, we have established a “dedifferentiated model” of adult murine CMs in coculture with CFs. In such a model, which is recognized to study cardiac cell hypertrophy in vitro, dedifferentiated CMs in culture and in coculture were characterized by immunopositive staining to ANP (atrial natriuretic peptide) and β‐myosin heavy chain (β‐MHC). The results confirm that ANP secretion by CMs was significantly increased during the cultures. The increase size of cultured CMs was significantly higher in CM/CF cocultures than in CM cultures which was also observed when CMs were cultured with fibroblast conditioned medium (FCM). In addition, fibroblast proliferation studies showed that CMs favored fibroblast adhesion and/or growth at the beginning of the coculture and fibroblast proliferation throughout the time course of the coculture. Furthermore, a significant level of interleukin‐6 (IL‐6) production was detected by ELISA in CM/CF cocultures. A similar higher increase was observed when CMs were cultured in the presence of FCM. These results demonstrate that CFs enhance myocyte hypertrophy and that CMs regulate fibroblast adhesion and/or proliferation, suggesting a paracrine interaction between CMs and CFs which could involve IL‐6. © 2004 Wiley‐Liss, Inc.
Membrane bioreactors vs conventional biological treatment of landfill leachate: a brief review
Authors: Alvarez‐Vazquez Héctor , Jefferson Bruce , Judd Simon J
Published: September 2004

A review of quality and biological treatment of landfill leachate is presented. Conventional ex‐situ treatment normally demands multistage process treatment schemes, which may encompass both aerobic and anaerobic technologies alongside chemical precipitation and/or oxidation. This is to be contrasted with the more recent membrane bioreactor technology, which generally demands much reduced pre‐ and post‐treatment and has a much reduced footprint compared with conventional biotreatment. Results are summarised in terms of the key determinant of COD removal for waters characterised in terms of BOD/COD ratio and age. Process operation is characterised with respect to COD strength and loading rate, hydraulic retention time and number of individual unit operations. Copyright © 2004 Society of Chemical Industry
Novel thin‐film reactor for photocatalytic degradation of pesticides in an aqueous solution
Authors: Shankar Muthukonda Venkatakrishnan , Anandan Srinivasan , Venkatachalam Nallusamy , Arabindoo Banumathi , Murugesan Velayutham
Published: September 2004

A thin‐film reactor was fabricated with immobilised TiO2 and this reactor was used for photocatalytic mineralisation of common pesticides, 2,4‐dichlorophenoxyacetic acid (DPA) and monocrotophos (MCP), and their commercially formulated products in an aqueous solution. Zeolites HY and Hβ with different physico‐chemical properties were chosen as support material. The supported TiO2 was used for the degradation and mineralisation studies. TiO2/zeolite‐supported photocatalyst showed enhanced degradation efficiency compared with bare TiO2 for both DPA and MCP. Formulated pesticides were mineralised at shorter irradiation times than technical grade pesticides. The results clearly demonstrated that the good adsorption capacity of the support, and the effective light utilisation by TiO2, improved the photocatalytic activity of supported TiO2. Reusability studies have also shown the stability of supported photocatalysts. Copyright © 2004 Society of Chemical Industry
Equilibrium data of the exchange of Cu2+, Cd2+ and Zn2+ ions for H+ on the cationic exchanger Lewatit TP‐207
Authors: Valverde José L , de Lucas Antonio , Carmona Manuel , González Marcela , Rodríguez Juan F
Published: September 2004

Equilibrium ion exchange isotherms in aqueous medium of H+/Cu2+, H+/Zn2+ and H+/Cd2+ on a weak acid resin Lewatit TP‐207, at different pH values and at 298 K have been determined in order to assess the possibility of using ion exchange to eliminate heavy metal ions from industrial aqueous liquid streams. The experimental equilibrium data have been satisfactorily correlated using a Langmuir‐type empirical equation. It was found that the operating resin capacity with respect to each metal ion increased with increase in solution pH, in accordance with a second‐degree polynomial equation. Taking into account the variation of operating capacity with pH, each system exhibited a unique separation factor, namely all the experimental points can be described by a unique isotherm in a dimensionless form. Resin Lewatit TP‐207 exhibited the following selectivity order: Cu2+ > Zn2+ > Cd2+ at 298 K. Copyright © 2004 Society of Chemical Industry
Puerperal vulvovaginal hematoma: Sonographic findings with MRI correlation
Authors: Guerriero Stefano , Ajossa Silvia , Bargellini Roberta , Amucano Giovanni , Marongiu Donatella , Melis Gian Benedetto
Published: September 2004

Puerperal hematomas are a major complication of delivery. Little information about the role of sonography in the management of puerperal hematomas is available in the English literature. We report a case of a vulvovaginal hematoma that developed subsequent to vaginal delivery and that was managed conservatively using sonography. Our report includes the sonographic follow‐up of the lesion with MRI correlation. The present case report suggests that sonography has a role in the detection and follow‐up of the condition, with MRI providing a more detailed mapping of the lesion and excluding any retroperitoneal involvement. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:415–418, 2004
Early abdominal sonographic findings in patients with dengue fever
Authors: Wu Keng‐Liang , Changchien Chi‐Sin , Kuo Chung‐Huang , Chiu King‐Wah , Lu Sheng‐Nan , Kuo Chung‐Mou , Chiu Yi‐Chun , Chou Yeh‐Pin , Chuah Seng‐Kee
Published: September 2004

Purpose

This study was conducted to evaluate the early sonographic findings in dengue hemorrhagic fever.

Methods

From July 2002 to September 2002, 86 patients were referred to our center with suspected dengue fever during an outbreak of the disease in Taiwan. All the patients underwent immediate abdominal sonography when they arrived at our emergency room. The diagnosis of dengue fever was subsequently confirmed by serology in 65 patients.

Results

All our patients had type 2 dengue fever, as confirmed by serologic tests. The sonographic features included a thickened gallbladder wall in 38 patients (59%), ascites in 24 patients (37%), splenomegaly in 22 patients (34%), and pleural effusion in 21 patients (32%); pleural effusion was either right‐sided or bilateral.

Conclusions

Abdominal sonography can be used as a first‐line imaging modality in patients with suspected dengue fever to detect early signs suggestive of the disease prior to obtaining serologic confirmation test results, especially in a dengue fever epidemic area. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:386–388, 2004
Synthesis of 5,5,6,6‐D4‐L‐lysine‐aflatoxin Bl for use as a mass spectrometric internal standard
Authors: Scholl Peter F. , Groopman John D.
Published: September 2004

Human exposure to the hepatocarcinogenic mycotoxin aflatoxin Bl results in modification of serum albumin lysine ε‐amino residues to form lysine‐aflatoxin adducts. A perdeuterated reference standard is now required to quantitatively measure this adduct in epidemiologic studies of liver cancer using isotopic dilution mass spectrometry. A convenient method for the preparation of D4‐L‐lysine‐AFBl using commercially available 5,5,6,6‐D4‐l‐lysine is demonstrated for the first time. The application of two standard α‐amino protection methods is also reported that simplifies the production of natural isotopic abundance lysine‐AFBl over the currently used method employing Nα‐acetyl‐l‐lysine. t‐Boc‐Nα‐lysine was used to prepare lysine‐AFBl; however, a preferred method for directing reaction of AFBl‐dialdehyde to the ε‐amino group of 5,5,6,6‐D4‐l‐lysine utilized cupric ions that were spontaneously removed during the reverse phase HPLC purification of D4‐lysine‐AFBl using 1% HOAc. This strategy eliminates the need to otherwise synthesize and purify t‐Boc‐Nα‐ or Nα‐acetyl‐5,5,6,6‐D4‐lysine and then TFA or enzymatically deprotect overnight to obtain the target compound. Copyright © 2004 John Wiley & Sons, Ltd.
Selective dissociation of non‐covalent bonds in biological molecules by laser spray
Authors: Takamizawa Atsushi , Itoh Yoshiyuki , Osawa Ryo , Iwasaki Noriyuki , Nishimura Yoshifumi , Akashi Satoko , Hiraoka Kenzo
Published: September 2004

The laser spray developed in our laboratory was applied to the analysis of bovine serum albumin (BSA), double‐stranded DNA (dsDNA) and a protein–DNA complex. The tip of a stainless‐steel capillary was irradiated with a 10.6 µm infrared laser by increasing the laser power from 0 W (electrospray) to 1.4 W. The laser beam was focused to about 0.3 mm at the tip of the stainless‐steel capillary. When BSA aqueous solution was irradiated by the laser, highly charged monomer ions were newly observed in addition to the multiply charged ions of non‐denatured monomer, dimer and trimer moieties. This indicates that BSA suffers from denaturation on irradiation with an infrared laser in solution. A 1.4 W laser power is not sufficient to cause the complete denaturation of BSA under the present experimental conditions. Whereas dsDNA was found to dissociate almost completely to single‐stranded DNA constituents on laser irradiation with a power of 1.2 W, no fragmentation of DNA molecules was observed. For a protein–DNA complex, i.e. a complex of c‐Myb DNA binding domain and dsDNA, dissociation of the complex to the component moieties was observed. These findings indicate that the laser spray can selectively dissociate non‐covalent complexes into subunits without causing dissociation of the covalent bonds of the subunits. The laser spray will be a versatile method for the investigation of the structures and stabilities of biomolecules including non‐covalent complexes. Copyright © 2004 John Wiley & Sons, Ltd.
HIV‐1 DNA burden dynamics in CD4 T cells and monocytes in patients undergoing a transient therapy interruption
Authors: Garbuglia Anna Rosa , Calcaterra Silvia , D'Offizi Gianpiero , Topino Simone , Narciso Pasquale , Lillo Flavia , Girardi Enrico , Capobianchi Maria Rosaria
Published: September 2004

Replication‐competent HIV, as well as HIV‐1 DNA, has been detected in CD4 T cells and in monocytes during antiretroviral therapy (ART), indicating that these cells could represent an important viral reservoir. We measured HIV‐1 DNA in monocytes and CD4 T cells in patients undergoing transient therapy interruption (TTI), to establish the dynamic of HIV‐1 DNA burden and to find possible correlations with immune restoration and re‐establishment of virological control after ART resumption. In most patients CD4 depletion and viral load rebound followed TTI. Rapid resumption of virological and immunological control was achieved after ART reintroduction. After TTI, in most cases a transient increase of both monocyte and CD4 HIV‐1 DNA burden was observed. After ART reintroduction, both CD4 T cell and monocyte HIV‐1 DNA copy number decreased, reaching baseline levels at the end of observation. At this time monocyte HIV‐1 DNA burden was always undetectable, while CD4 T cell HIV‐1 DNA burden was lower than at baseline. As CD4 T cell HIV‐1 DNA values are independently associated with CD4 depletion, the increase of HIV‐1 DNA burden in these cells after TTI is presumably due to acute infection, causing cell death. This is also supported by the pattern of 2‐LTR appearance in these cells after TTI. HIV‐1 DNA burden in monocytes and CD4 T cells show high correlation, suggesting reciprocal re‐feeding of two cell populations. Repopulation by HIV these cells after TTI is temporary, and no significant changes of HIV‐1 DNA burden were observed after ART resumption respect to pre‐TTI period. J. Med. Virol. 74:373–381, 2004. © 2004 Wiley‐Liss, Inc.
Retrospective, longitudinal analysis of serum human herpesvirus‐8 viral DNA load in AIDS‐related kaposi's sarcoma patients before and after diagnosis
Authors: Polstra Abeltje M. , Cornelissen Marion , Goudsmit Jaap , van der Kuyl Antoinette C.
Published: September 2004

Human herpesvirus 8 (HHV‐8) is detected more often in patients progressing towards Kaposi's sarcoma (KS) than in patients who do not develop the disease, suggesting that the level of viremia might be associated with Kaposi's sarcoma disease and progression. Longitudinal serum samples from 19 AIDS‐Kaposi's sarcoma patients, ranging from 2 years before KS till 2 years after KS diagnosis were tested. No correlation was found between viral load and progression to KS, or disease stage. J. Med. Virol. 74:390–396, 2004. © 2004 Wiley‐Liss, Inc.
Epstein–Barr virus‐encoded dUTPase modulates immune function and induces sickness behavior in mice
Authors: Padgett David A. , Hotchkiss Andrew K. , Pyter Leah M. , Nelson Randy J. , Yang Eric , Yeh Peir‐En , Litsky Monica , Williams Marshall , Glaser Ronald
Published: September 2004

Epstein–Barr virus (EBV) is the causative agent of infectious mononucleosis (IM). In addition, latent infections with EBV are associated with nasopharyngeal carcinoma (NPC) and Burkitt's Lymphoma (BL). Antibodies to several EBV‐encoded early antigens (EA) are often observed in patients with NPC and BL, however, the role of EBV‐encoded proteins in the etiology of these and other EBV‐associated diseases is not completely understood. The EA complex encodes for at least six different viral enzymes including deoxyuridine triphosphate nucleotidohydrolase (dUTPase). dUTPase has recently been shown to modulate activation of human peripheral blood mononuclear cells in vitro (unpublished data). Therefore, these studies were designed to test whether dUTPase would modulate immune function in an in vivo model. Mice were injected with purified EBV dUTPase, and baseline immune function and sickness behaviors were measured. EBV dUTPase treatment inhibited replication of mitogen‐stimulated lymphocytes obtained from treated mice. These lymphocytes were also less able to synthesize interferon‐γ after re‐stimulation. In addition, treatment with dUTPase induced sickness behaviors. For example, as compared to control animals, dUTPase‐treated animals lost body mass, had elevated body temperature, and displayed diminished locomotor activity. These data suggest that individual viral proteins may play a role in the pathophysiology of EBV associated disease. J. Med. Virol. 74:442–448, 2004. © 2004 Wiley‐Liss, Inc.
Modulation of apoptosis during HTLV‐1‐mediated immortalization process in vitro
Authors: Matteucci Claudia , Balestrieri Emanuela , Macchi Beatrice , Mastino Antonio
Published: September 2004

Suppression of apoptosis has been proposed as a mechanism involved in the transforming action of human T‐cell leukemia/lymphotropic virus type‐1 (HTLV‐1). However, there is evidence that HTLV‐1 and its protein Tax also induce apoptosis. To resolve this apparent paradox, apoptosis was monitored in primary cultures of peripheral blood lymphocytes (PBLs) from healthy donors, following HTLV‐1 infection in vitro. High levels of apoptosis in HTLV‐1 infected cultures during the first weeks after infection were detected. Apoptosis was not related to the presence of uninfected cells, as revealed by a fluorescence in situ hybridization assay. Successively, a progressive decrease in apoptosis in infected cultures going towards immortalization, was observed. When IL‐2 in the medium was replaced by IL‐4, allowing the cells to be efficiently infected by HTLV‐1 but not immortalized, apoptosis levels tended to increase, instead of decreasing, with the ongoing time. The caspase cascade was remarkably activated in PBLs recently infected in vitro by HTLV‐1, but apoptosis was only partly reduced by caspase inhibitors. Even if spontaneous apoptosis was relatively low in long‐term cultures of PBLs immortalized by HTLV‐1 in vitro, Fas death‐receptor expression and function were well conserved. These observations provide a new rationale for explaining the dual effect of HTLV‐1 in controlling apoptosis. J. Med. Virol. 74:473–483, 2004. © 2004 Wiley‐Liss, Inc.
UV‐induced apoptosis in SH‐SY5Y cells: Contribution to apoptosis by JNK signaling and cytochrome c
Authors: Berglund C. Mikaela D. , Radesäter Ann‐Cathrin , Persson Mats A.A. , Budd Haeberlein Samantha L.
Published: September 2004

Activation of the c‐Jun N‐terminal kinase (JNK) pathway is suggested to be required for neuronal apoptosis. We investigated the role of JNK on phosphorylation of c‐Jun, Bcl‐2, and apoptotic translocation of cytochrome c (cyt c) in UV‐induced apoptosis in human neuroblastoma SH‐SY5Y cells. We confirm that UV irradiation induces both apoptosis and necrosis in SH‐SY5Y cells and that phosphorylation of JNK at Thr183/Tyr185 in SH‐SY5Y cells treated with UV is an early event preceding apoptosis. We also demonstrate that phosphorylation of c‐Jun at Ser63 is an early event coinciding with JNK activation, and that the phosphorylation of c‐Jun is partially prevented by the JNK inhibitor SP600125. Despite the use of SP600125, the amount of cyt c released into the cytoplasm is not diminished and SP600125 is also unable to decrease the extent of UV‐induced apoptosis. These data support the hypothesis that in this system, UV‐induced apoptosis is not dependent exclusively on JNK activation. Possible involvement of cyclin‐dependent kinases (CDKs) in c‐Jun phosphorylation at Ser63 was excluded by pretreating UV‐irradiated SH‐SY5Y cells with the CDK1/2/5 inhibitor roscovitine. © 2004 Wiley‐Liss, Inc.
Alterations in spinal cord gene expression after hindpaw formalin injection
Authors: Li Xiangqi , Lighthall Geoff , Liang De‐Yong , Clark J. David
Published: September 2004

Heme oxygenase type 2 (HO‐2) is an enzyme that uses heme as a substrate to produce iron, biliverdin, and carbon monoxide (CO). This enzyme participates in regulation of nociceptive signal transmission in spinal cord tissue. We set out to identify genes undergoing alterations in expression in a model of inflammatory pain and to determine whether HO‐2 participates in that regulation. After the hindpaw injection of formalin in mice, we measured changes in expression of immediate early genes including c‐fos, c‐jun, jun B, nerve growth factor induced genes (NGFI‐A and NGFI‐B) and activity‐related cytoskeletal protein (ARC) using real‐time PCR. The mRNA corresponding to these genes increased in abundance in the first hour after formalin injection and then slowly declined. Changes in the abundance of prodynorphin, extracellular signal related kinases (ERK1 and ERK2) and N‐methyl‐D‐aspartate (NMDA) receptor R1 subunit mRNA generally peaked between 8 and 12 hr after formalin injection. In HO‐2 null mutant mice, the enhancement of expression was less for all genes studied. We went on to quantify gene expression in superficial dorsal horn tissue using laser capture microdissection followed by RNA amplification and real‐time PCR. The results confirmed that the changes in gene expression were occurring in regions of the spinal cord involved in nociceptive processing. We conclude that the hindpaw injection of formalin leads to enhanced early and late expression of many genes in spinal cord dorsal horn tissue, and that this enhancement of expression relies to a degree on the presence of HO‐2. © 2004 Wiley‐Liss, Inc.
Adsorption of 3‐ and 4‐benzoylpyridine on colloidal silver particles: a surface‐enhanced Raman scattering study
Authors: Chowdhury Joydeep , Ghosh Manash
Published: September 2004

Surface‐enhanced Raman scattering (SERS) spectra of 3‐ and 4‐benzoylpyridine (BP) adsorbed on silver hydrosols were compared with the FTIR and normal Raman spectra in bulk and in solution. With a small fractional change in adsorbate concentration, the SER spectra of isomeric BPs show significant changes in their features, indicating different orientational changes of the different parts of the flexible molecule on the colloidal silver surface with adsorbate concentration. The appearance of a broad, long‐wavelength band in the absorption spectra of the silver sol due to solute‐induced coagulation of colloidal silver particles is found to be red shifted with increase in adsorbate concentration. The SER excitation profiles indicate that the resonance of the Raman excitation radiation with the new aggregation band contributes more to the SERS intensity than that with the original sol band. Copyright © 2004 John Wiley & Sons, Ltd.
Variability in starch physicochemical and functional properties of yam (Dioscorea sp) cultivated in Ivory Coast
Authors: Amani N'Guessan Georges , Buléon Alain , Kamenan Alphonse , Colonna Paul
Published: September 2004

An Erratum has been published for this article in Journal Of the Science of Food and Agriculture 85(5), 889 (2005).

Native starches were extracted from 21 cultivars of four yam species representative of the yam population of Ivory Coast. They were first characterized for their proximate composition, starch physico‐chemical properties (amylose content, particle size distribution, crystallinity, thermal properties and intrinsic viscosity). Some functional properties (swelling, solubility and pasting behaviour and paste clarity) were then determined. Analysis of variance and principal component analysis showed that three homogenous groups could be distinguished, mainly based on starch physico‐chemical properties. The first group contained all yam starches of the D alata and the D cayenensis‐rotundata complex species. It was characterized by a large diameter grain (approximately 25 µm), a high amylose content (around 25% db), a high intrinsic viscosity (mean of 190 cm3 g−1), and a high apparent viscosity and clarity of the paste. The second group contained the D esculenta varieties, characterized by a small granule size (diameter 6 µm), a low intrinsic viscosity (121 cm3 g−1), a high gelatinization enthalpy change (19 J g−1) and a low paste viscosity. The D dumetorum sample differed from the D esculenta group by having a pure A‐type crystalline form and an opaque paste. A multiple regression showed that the volume fraction of the dispersed phase and native granule size (or amylose content) could account for close to 80% of the variability of paste apparent viscosity. Gel clarity appeared mainly linked to granule size, small granules from D dumetorum and D esculenta giving the most opaque gels. Copyright © 2004 Society of Chemical Industry
Carrot browning on simulated market shelf and during cold storage
Authors: Zhang Qijing , Tan Soonchye , McKay Allan , Yan Guijun
Published: September 2004

Browning index, degree of browning, total phenolics content and polyphenoloxidase (PPO) activity of three carrot cultivars—Kendo, Ricardo and Stefano—were studied on a simulated market shelf (20 °C) and during cold storage (4 °C). There was a general increase in browning indices and degree of browning during simulated marketing storage for all three cultivars. The three cultivars had similar levels of browning after cold storage but Ricardo reached the highest level after 10 days of simulated shelf life. There appeared to be a rapid increase in total phenolics content during cold storage, which increased further during a simulated marketing trial. The PPO activities of Kendo and Stefano decreased during cold storage whereas that of Ricardo increased, reaching its highest level after 2 months in cold storage. A positive and significant correlation between total phenolics and degree of browning was found for all three cultivars stored for different lengths of time. This research suggests that shorter periods of cold storage reduce the potential for carrot browning and hence prolong the shelf life of carrots. Copyright © 2004 Society of Chemical Industry
Semipreparative isolation of dehydrodiferulic and dehydrotriferulic acids as standard substances from maize bran
Authors: Bunzel Mirko , Funk Carola , Steinhart Hans
Published: September 2004

A method for the isolation of diferulic and triferulic acids in quantities and purity that comply with the requirements for their use as standard substances was developed. The procedure includes alkaline hydrolysis of destarched maize bran and ether extraction of liberated phenolic compounds. Following a first purification by liquid‐liquid extraction Sephadex LH‐20 chromatography is performed. This step is the core of the method and allows the separation of monomeric and dimeric/trimeric substances. A good pre‐separation of di‐ and triferulic acids (purity in most cases >75%) is also achieved. Further separation and purification is carried out by semipreparative RP18‐HPLC. Using this rapid, easy to handle, and moderately priced separation procedure it is possible to obtain approx. 41 mg 8‐O‐4´‐diferulic acid, 27 mg 5‐5´‐diferulic acid, 12 mg 8‐5´‐diferulic acid (benzofuran form), 16 mg 8‐5´‐diferulic acid (open form), 11 mg 8‐5´‐diferulic acid (decarboxylated form), 7 mg 8‐8´‐diferulic acid (cyclic form), 5 mg 8‐8´‐diferulic acid (open form), and 10 mg 5‐5´,8´‐O‐4´´‐triferulic acid out of 20 g destarched maize bran. The incorporation of minor modifications allows a further upscaling of this procedure.
Blue‐Green Light Emitting Poly(phenylenevinylene) Derivatives as Candidates for Polymer LEDs: Synthesis and Characterization
Authors: Mahler A. Kai , Schlick Horst , Saf Robert , Stelzer Franz , Meghdadi Farideh , Pogantsch Alexander , Leising Günther , Möller Kai‐Christian , Besenhard Jürgen O.
Published: September 2004

Summary: Alkoxy substituted derivatives of poly‐ and oligo[(m‐phenylenevinylene)‐alt‐(p‐phenylenevinylene)] were synthesized via the Wittig (P1, OPV1, OPV2) and the Wittig‐Horner (P2, OPV3, OPV4) condensation routes. The polymers were characterized by 13C NMR, 1H NMR, FT‐IR spectroscopy and GPC. 1H NMR was a convenient tool to distinguish between the cis and trans double bonds in the compounds. Poly[(4‐decyloxy‐1,3‐phenylenevinylene)‐alt‐(1,4‐phenylenevinylene)] (P1) contained cis and trans double bonds in significant amounts, the vinylene configuration of poly[(4‐decyloxy‐1,3‐phenylenevinylene)‐alt‐(2,5‐dipentyloxy‐1,4‐phenylenevinylene)] (P2) was nearly exclusively trans. Model compounds (OPV1–4) were also synthesized to support the structural and optical characterization. UV‐vis absorption, photoluminescence (PL) and cyclic voltammetry measurements have been performed to investigate the influence of the positions and the number of substituents on electronic levels. The polymers exhibited an intensive solid‐state emission in the blue‐green (P1) and the green (P2) region of the spectrum. Light emitting diodes have been fabricated consisting of ITO, PEDOT:PSS, P2 and Ca/Al. They exhibited high luminance of 100 cd · m−2 at 5.9 V and low onset voltages (4.3 V) for the electroluminescence (EL).

Schematic representation of a light emitting diode fabricated by use of an alkoxy substituted derivative of poly[(m‐phenylenevinylene)‐alt‐(p‐phenylenevinylene)] (P2).

magnified image

Schematic representation of a light emitting diode fabricated by use of an alkoxy substituted derivative of poly[(m‐phenylenevinylene)‐alt‐(p‐phenylenevinylene)] (P2).
Preparation and Characterisation of Hydrophobically Modified Hydroxypropylcellulose: Side‐Chain Crystallisation
Authors: López‐Velázquez Delia , Bello Antonio , Pérez Ernesto
Published: September 2004

Summary: Hydroxypropylcellulose has been hydrophobically modified by reaction with different amounts of palmitoyl chloride. When the degree of substitution is sufficiently high, the side chains are able to produce lateral crystallisation, which has been analysed by DSC and diffraction experiments, using both conventional and synchrotron radiation. The melting temperatures and enthalpies depend on the degree of substitution, in such a way that it is relatively easy to get melting temperatures close to that of the human body, although a rather wide melting region is obtained.

X‐ray diffractograms of the original HPC sample and of the modified specimens.

magnified image

X‐ray diffractograms of the original HPC sample and of the modified specimens.
Soluble Polyimide Containing a Photoreactive 2‐Styrylpyridine Derivative as the Side Group: Synthesis and Characterization
Authors: Kim Woo‐Sik , Ahn Deuk‐Kyoon , Kim Min‐Woo
Published: September 2004

Summary: We describe the synthesis and characterization of a soluble photoreactive polyimide. The precursor of the polyimide was prepared from 2,2′‐bis{4‐(3,4‐dicarboxyphenoxy)phenyl}hexafluoropropane dianhydride and 3,3′‐hydroxy‐4,4′‐diaminobiphenyl; the photoreactive polyimide was then prepared by the polymer reaction of the hydroxyl groups in the precursor polymer with 2‐{2‐[4‐(6‐hydroxyhexyloxy)phenyl]ethenyl}pyridine as a photoreactive 2‐styrylpyridine derivative. The photoreactive polymer and its precursor polymer were soluble in various polar organic solvents, and their thin flexible films were easily formed by solution casting. The initial decomposition temperatures of the former and latter polymers were 350 and 470 °C, respectively. The extent of the photochemical reaction of the photoreactive polymer film was measured to be 65.8% at an exposure energy of 1.5 J/cm2. The transmittance of the film was found to be approximately 92% at room temperature and approximately 85% at 200 °C. These results suggest that the polyimide is a photosensitive polymer with good photosensitivity and high optical transparency. The dichroic ratios of the film were between 0.023 and 0.025 when exposed to linearly polarized UV light (LPUVL). The liquid crystal in the film cell was perpendicularly oriented to the electric vector of LPUVL.

Polar diagrams of LC cells fabricated from polyimide 6FBPA‐HAB‐SP6 film after irradiation with LPUVL.

magnified image

Polar diagrams of LC cells fabricated from polyimide 6FBPA‐HAB‐SP6 film after irradiation with LPUVL.
Cover Picture: Macromol. Mater. Eng. 9/2004
Authors: Pastore Heloise O. , Frache Alberto , Boccaleri Enrico , Marchese Leonardo , Camino Giovanni
Published: September 2004

Cover: The picture on the cover illustrates heat induced structure modifications in polymer‐layered silicate nanocomposites.

Further details can be found in the Full Paper by H. O. Pastore, A. Frache, E. Boccaleri, L. Marchese,* and G. Camino on page 783.
Fourier embeddings and Mihlin‐type multiplier theorems
Authors: Hytönen Tuomas
Published: September 2004

Recent theorems on singular convolution operators are combined with new Fourier embedding results to prove strong multiplier theorems on various function spaces (including Besov, Lebesgue–Bôchner, and Hardy). All the results apply to operator‐valued multipliers acting on vector‐valued functions, but some of them are new even in the scalar case. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some equivalent representations of nonsquare constants of spaces with Orlicz norm
Authors: Yan Ya Qiang
Published: September 2004

The nonsquare constants in sense of James and Schäffer have the interrelation: CJ (X) · CS(X) = 2 for a Banach space X. For Orlicz sequence and function spaces equipped with Luxemburg norm, the representation of CJ and CS were obtained ([6], [7]). In this paper, we show that the nonsquare constants CJ (lΦ), CJ(LΦ(Ω)) in sense of James and CS(lΦ), CS(LΦ(Ω)) in sense of Schäffer satisfy:

(i) if ϕ(t) is concave, then

(ii) if ϕ(t) is convex, then

with lΦ and LΦ(Ω) being the Orlicz sequence space and function space generated by the N‐function Φ(u) with Orlicz norm, ϕ(t) being the right derivative of Φ. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure‐Property Relationships in Rubber‐Modified Styrenic Polymers
Authors: Heckmann Walter , McKee Graham Edmund , Ramsteiner Falko
Published: September 2004

Styrenic polymers and copolymers are often impact modified with rubber particles. The efficiency of rubber toughening depends mainly on the size of the rubber particles and the degree of cross‐linking. The deformation rate, the temperature, the orientation of the polymer molecules and the efficiency of rubber grafting also influence rubber toughening. It is thought that on impact, cavitation inside the rubber particles occurs which reduces the detrimental dilatational stress in the bulk polymer without forming cracks in the brittle matrix or at the rubber‐matrix interface. Crazing and shearing are facilitated if the rubber particles can easily cavitate. This can be achieved by either avoiding too much cross‐linking or by adding oil (silicone oil in the case of ABS) into the rubber particles, which acts as nuclei for void formation. An electron spectroscopic imaging method is described which allows visualizing the location of the oil. Already after cooling silicone oil modified ABS samples down to liquid nitrogen temperature rubber cavitation is observed. This cavitation is caused by the thermal stress developing due to the differences in thermal expansion coefficient between the rubber phase and the SAN‐matrix and is facilitated by silicone oil. Voiding also leads to an increase of light scattering, which can be detected by an optical microscope using dark field illumination.
Structure, Dynamics and Properties of Materials with Polymers Having Complex Architectures
Authors: Pakula Tadeusz
Published: September 2004

Various non‐linear highly branched polymers such as multiarm stars, block copolymer micelles and bottlebrush‐like polymers have been studied in order to analyze their intramolecular structure and effects of spatial ordering resulting from their specific macromolecular architecture. These polymers constitute a class of compact macromolecules which, due to the high intramolecular density, interact strongly, excluding each other in space. Investigations of the structure and dynamics in such systems, using various experimental methods as well as computer simulations, have been performed. Small angle X‐ray scattering is used to characterize the structure and mechanical spectroscopy is used for the detection of the dynamic behavior of the systems. Simulations have been performed using the cooperative motion algorithm with lattice polymers equivalent to the considered macromolecules. Results of both experiments and the simulation seem to support the concept of slow structural cooperative rearrangements controlling the flow in such systems. The effects are analogous to those related to flow in low molecular liquids but take place on another size scale. The new slow relaxation processes creates new super soft‐states which are characterized by shear modulus plateau lower than 104 Pa.
Phase II enzyme inducer, sulforaphane, inhibits UVB‐induced AP‐1 activation in human keratinocytes by a novel mechanism
Authors: Zhu Ming , Zhang Yuesheng , Cooper Simon , Sikorski Ewa , Rohwer John , Bowden G. Timothy
Published: September 2004

Ultraviolet (UV) light‐induced activation of activator protein‐1 (AP‐1), resulting at least in part from oxidative stress, promotes skin carcinogenesis. It has not yet been determined whether elevating cellular phase II enzymes and glutathione (GSH) levels inhibits the AP‐1 activation. We have, therefore, examined the effects of two well‐known inducers of phase II enzymes, sulforaphane (SF) and tert‐butylhydroquinone (tBHQ), on UVB‐induced AP‐1 activation, with an AP‐1‐luciferase reporter plasmid that was stably transfected into human HaCaT keratinocytes (HCL14 cells). Exposure of HCL14 cells to SF or tBHQ led to the induction of quinone reductase‐1 (QR‐1), a marker of global cellular phase II enzymes, as well as elevation of cellular GSH levels. Incubation of the cells with 1–10 μM SF or 11–45 μM tBHQ for 24 h resulted in up to 1.4‐fold and 1.7‐fold increase of QR‐1 activity, respectively, and up to 1.5‐fold and 1.6‐fold increases in cellular GSH levels, respectively. AP‐1 activation was dramatically enhanced by irradiating HCL14 cells with 250 J/m2 of UVB. While the above SF treatment dose‐dependently reduced the UVB‐induced AP‐1 activation in HCL14 cells, the tBHQ treatment did not, suggesting that elevating cellular phase II enzymes and GSH levels may not lead to inhibition of UVB‐induced AP‐1 activation. Indeed, depleting cellular GSH by 80% did not affect UVB‐induced AP‐1 activation either. Subsequent electrophoretic mobility shift assays (EMSA) showed that SF added directly to the EMSAs inhibited AP‐1 DNA binding activity, whereas tBHQ was ineffective. Taken together, our results indicated that elevating phase II enzymes and GSH levels in human keratinocytes does not lead to significant inhibition of UVB‐induced AP‐1 activation. The inhibitory effect of SF on UVB‐induced AP‐1 activation appears to be at least partly due to the direct inhibition of AP‐1 DNA binding activity. This direct effect of SF on AP‐1 DNA binding is a novel mechanism for the action of a drug inhibitor of AP‐1 activation. © 2004 Wiley‐Liss, Inc.
The one‐dimensional chemotaxis model: global existence and asymptotic profile
Authors: Hillen Thomas , Potapov Alex
Published: September 2004

Osaki and Yagi (2001) give a proof of global existence for the classical chemotaxis model in one space dimension with use of energy estimates. Here we present an alternative proof which uses the regularity properties of the heat‐equation semigroup. With this method we can identify a large selection of admissible spaces, such that the chemotaxis model defines a global semigroup on these spaces.

We use scaling arguments to derive the asymptotic profile of the solutions and we show numerical simulations. Copyright © 2004 John Wiley & Sons, Ltd.
An air‐substrate narrow‐patch microstrip antenna with high radiation performance for 2.4 GHz WLAN access point
Authors: Liu Yung‐Tao , Su Che‐Wei , Wong Kin‐Lu , Chen Hong‐Twu
Published: September 2004

A new narrow‐patch microstrip antenna with high radiation performance is presented. By using a feeding structure composed of a step‐shaped feeding strip in the air substrate and a coplanar strip in the narrow radiating patch, the proposed antenna shows high gain (about 8.3–9.2 dBi), wide azimuthal radiation pattern (3‐dB beamwidth close to 90°), and reduced cross‐polarization radiation (less than −20 dB) for frequencies across the 2.4‐GHz (2400–2484 MHz) WLAN band. Experimental results of a constructed prototype suitable for application in the 2.4‐GHz WLAN access point are presented and discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 189–192, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20416
On the general energy‐absorption mechanism in the human tissue
Authors: Kivekäs Outi , Lehtiniemi Tuukka , Vainikainen Pertti
Published: September 2004

In this paper, the general energy‐absorption mechanism in human tissue is investigated. The purpose is to increase the understanding of this process, which is important, for example, when designing mobile handset antennas with minimized user interaction. The behavior of the electric fields of small antennas located near a lossy dielectric half‐space, which consists of several material layers, is studied by numerical simulations. Two different RF sources operating at 900 MHz are used: a half‐wave dipole and a patch antenna on a mobile handset chassis. The results show that the peak specific absorption rate (SAR) is not actually related to the antenna current, as has been commonly believed. Instead, the location of the SAR maximums can be explained by inspecting the boundary conditions of the quasi‐static electric near‐fields of the antenna at the air‐tissue interface. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 195–201, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20418
Optical carrier‐suppression of microwave signals with stimulated Brillouin scattering in long fiber ring
Authors: Shen Yichun , Zhang Xianmin , Chen Kangsheng
Published: September 2004

A novel and simple system based on stimulated Brillouin scattering in long fiber ring for optical‐carrier suppression is presented. In this system, a large optical carrier reduction can be attained easily at relative low input power. The anti‐Stokes wave is inhibited by adjusting the Stokes wave feedback. Experiments are implemented to suppress the optical carrier of a microwave photonics signal. About 35‐dB optical carrier reduction and a modulation‐gain factor of 27 are achieved. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 258–260, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20436
Structural characterization and quantitation of compound loading of disubstituted benzoates bound to Wang resin through high‐resolution magic angle spinning NMR spectroscopy
Authors: Blas Jesús , Rivera‐Sagredo Alfonso , Ferritto Rafael , Espinosa Juan Felix
Published: September 2004

The combination of 1D and 2D high‐resolution magic angle spinning NMR experiments led to the assignment of the proton and carbon resonances for several disubstituted benzoates bound to a polystyrene resin through a Wang linker. It is shown that the signal corresponding to the methylene protons of the linker can be utilized to monitor the solid‐phase reactions and determine the loading of the compounds on the resin. Copyright © 2004 John Wiley & Sons, Ltd.
The effects of seizures on the connectivity and circuitry of the developing brain
Authors: Swann John W.
Published: September 2004

Recurring seizures in infants and children are often associated with cognitive deficits, but the reason for the learning difficulties is unclear. Recent studies in several animal models suggest that seizures themselves may contribute in important ways to these deficits. Other studies in animals have shown that recurring seizures result in dendritic spine loss. This change, coupled with a down‐regulation in NMDA receptor subunit expression, suggests that repetitive seizures may interrupt the normal development of glutamatergic synaptic transmission. We hypothesize that homeostatic, neuroprotective processes are induced by recurring early‐life seizures. These processes, by diminishing glutamatergic synaptic transmission, are aimed at preventing the continuation of seizures. However, by preventing the normal development of glutamatergic synapses, and particularly NMDA receptor‐mediated synaptic transmission, such homeostatic processes also reduce synaptic plasticity and diminish the ability of neuronal circuits to learn and store memories. MRDD Research Reviews 2004;10:96–100. © 2004 Wiley‐Liss, Inc.