bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of [5,6]‐ and [6,6]‐Oxahomofullerene Derivatives and Their Interconversion by Lewis Acid Assisted Reactions of Fullerene Mixed Peroxides
Authors: Huang Shaohua , Xiao Zuo , Wang Fudong , Zhou Jiang , Yuan Gu , Zhang Shiwei , Chen Zhongfang , Thiel Walter , Schleyer Paul von Ragué , Zhang Xiang , Hu Xiangqing , Chen Bichu , Gan Liangbing
Published: July 2005

[60]Fullerene mixed peroxides C60(O)(OOtBu)4 exhibit chemo‐ and regioselective reactions under mild conditions. The epoxy moiety is opened by ferric chloride to form vicinal hydroxy chloride C60Cl(OH)(OOtBu)4. BF3 is also effective in opening the epoxy moiety. The OO bond of the fullerene mixed peroxide is cleaved by aluminum chloride to form both [5,6]‐ and [6,6]‐fullerene hemiketals (oxohomo[60]fullerenes). A Hock‐type rearrangement is proposed for the formation of the hemiketals, in which a fullerene CC bond is cleaved. Lewis acids and/or visible light can initiate isomerization of the hemiketal isomers. Single‐crystal X‐ray analysis and theoretical calculations confirmed the results.
Retroperitoneal soft tissue sarcoma
Authors: Mendenhall William M. , Zlotecki Robert A. , Hochwald Steven N. , Hemming Alan W. , Grobmyer Stephen R. , Cance William G.
Published: July 2005

The objective of the current study was to define the optimal treatment for patients with retroperitoneal soft tissue sarcomas (RPS). The authors conducted a review of the pertinent literature and found that the majority of patients had locally advanced RPS at the time of diagnosis. Surgery was the mainstay of treatment, and macroscopic total excision was feasible in approximately 50–67% of patients. The 5‐year probability of local control was approximately 50%, and the likelihood of developing distant metastasis was approximately 20–30%. The 5‐year survival rate was approximately 50%, and deaths due to recurrent RPS continued to occur after 5 years. Postoperative radiotherapy (RT) decreased the likelihood of local recurrence, although it demonstrated no impact on survival. Adjuvant chemotherapy had no proven efficacy. The factor that was found to have the greatest impact on the prognosis for patients with RPS was the ability to achieve a macroscopic total resection. The authors concluded that RPS usually is advanced at the time of diagnosis. The optimal treatment was complete resection. Most patients experienced recurrent disease after surgery, and the most common site of failure was local. Adjuvant RT reduced the risk of local recurrence, but its impact on survival was questionable. Cancer 2005. © 2005 American Cancer Society.
Assay to measure CD59 mutations in CHO AL cells using flow cytometry
Authors: Ross Carley D. , Lim Chang‐Uk , Fox Michael H.
Published: July 2005

Background

A sensitive mammalian cell mutation assay was developed previously using a Chinese hamster ovary cell line (CHO AL) that stably incorporates human chromosome 11. The assay measures mutations in the CD59 gene on chromosome 11 but it requires the use of rabbit complement and colony growth for mutant selection. We have developed a more rapid flow cytometry‐based mutation assay with CHO AL cells that uses monoclonal antibodies against CD59 to detect mutants and does not require colony formation.

Methods

CHO AL cells were treated with γ‐radiation or N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) and then allowed to grow for various times for mutant expression. Cells were labeled with monoclonal antibodies against CD59 and analyzed by flow cytometry.

Results

Negative and positive populations were separated by over 100‐fold. Mixing various proportions of CD59‐positive and ‐negative cells demonstrated that the assay is highly linear (r2 = 0.9999) and sensitive (<0.05% background mutants). The yield of CD59‐inducible mutants was linearly related to dose for a clastogen (γ‐radiation) and point mutagen (MNNG). The mutant yield was time and treatment specific.

Conclusions

Mutations induced by genotoxic agents can be rapidly and sensitively measured in CHO AL cells using flow cytometry. © 2005 Wiley‐Liss, Inc.
Temporal and spatial expression of liver receptor homologue‐1 (LRH‐1) during embryogenesis suggests a potential role in gonadal development
Authors: Hinshelwood Margaret M. , Shelton John M. , Richardson James A. , Mendelson Carole R.
Published: July 2005

Liver receptor homologue‐1 (LRH‐1), an orphan member of the nuclear receptor family highly expressed in adult mouse ovary, is closely related to steroidogenic factor 1 (SF‐1), known to be important in gonadal formation. To analyze the potential role of LRH‐1 in gonadal differentiation, we compared LRH‐1 and SF‐1 expression during mouse embryonic and postnatal development. LRH‐1 expression was first detected in the urogenital ridge before sexual determination, in primordial germ cells and surrounding somatic cells; expression persisted after differentiation into testes and ovaries. Of interest, LRH‐1 expression declined in the developing ovary and testis at embryonic day 15.5 but increased again just after birth in the ovary in granulosa cells and transiently in oocytes of developing follicles. By comparing and contrasting LRH and SF‐1 expression with the two tissue‐specific steroidogenic markers, cytochromes P450 aromatase and P450 17α‐hydroxylase/17,20 lyase, we provide evidence for a potential role for LRH‐1 in gonadal development, the initiation of folliculogenesis and regulation of estrogen biosynthesis within the ovary. Developmental Dynamics 234:159–168, 2005. © 2005 Wiley‐Liss, Inc.
Atom Transfer Radical Additions with the Cationic Half‐Sandwich Complex [Cp*Ru(PPh3)2(CH3CN)]OTf
Authors: Quebatte Laurent , Scopelliti Rosario , Severin Kay
Published: July 2005

The cationic ruthenium half‐sandwich complex [Cp*Ru(PPh3)2(CH3CN)][OTf] (2) (Cp* = η5‐C5Me5, OTf = SO3CF3) was synthesized by reduction of [Cp*RuCl2]2 with zinc in the presence of NaOTf and subsequent reaction with PPh3. When NaOTf was omitted, the corresponding tetrachlorozincate salts were obtained. Complex 2, as well as the salts [Cp*Ru(CH3CN)3]2[ZnCl4] (3) and [Cp*Ru(PPh3)2(CH3CN)]2[ZnCl4] (4), were characterized by single‐crystal X‐ray analysis. Complex 2 proved to be a potent catalyst for the atom transfer radical addition of CCl4 and CHCl3 to terminal olefins, displaying a performance superior to that of the previously described neutral catalyst [Cp*RuCl(PPh3)2]. For the addition of CHCl3 to styrene, a total turnover number of 890 was achieved. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Stereoselective Synthesis of the 5,5‐Difluoro‐(12R)‐ and ‐(12S)‐Leukotrienes B3
Authors: Lingam Manthati Vijaya , Grée Danielle , Grée René
Published: July 2005

The first synthesis of the 5,5‐difluoro‐(12R)‐ and ‐(12S)‐leukotrienes B3 is reported which uses a flexible and convergent strategy. The key steps involve a Sonogashira coupling between the bromodienone 4 and the propargylic difluoride 5; this is followed by a CBS type reduction to establish the (12R) or (12S) stereocenters. A final semihydrogenation, under controlled conditions, affords the required E,E,Z trienic system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Matrix‐degrading proteases ADAMTS4 and ADAMTS5 (disintegrins and metalloproteinases with thrombospondin motifs 4 and 5) are expressed in human glioblastomas
Authors: Held‐Feindt Janka , Paredes Elke Bernedo , Blömer Ulrike , Seidenbecher Constanze , Stark Andreas M. , Mehdorn H. Maximilian , Mentlein Rolf
Published: July 2005

Brain tumors, in particular glioblastomas, have a high morbidity and mortality, mainly due to their invasive nature. A prerequisite for this invasiveness is cell migration based on increased expression of proteases digesting the extracellular matrix. Brevican, an important extracellular proteoglycan that is upregulated in glioblastomas, can be degraded by certain proteases. We demonstrate that in human glioblastomas secretory proteases like ADAMTS4 and ADAMTS5 (aggrecanases 1 and 2; ADAMTS = a disintegrin and metalloproteinase with thrombospondin motifs) are expressed on the mRNA and protein levels in considerable amounts. Real‐time RT‐PCR shows a higher levels of ADAMTS4 and 5 expressions in glioblastomas in situ, compared to cultured human glioblastoma cells. The upregulation of these proteases in vivo by cytokines may explain this difference. In vitro, transforming growth factor‐β induces ADAMTS4, but less ADAMTS5, and interleukin‐1β ADAMTS5, but not ADAMTS4. As demonstrated by immunohistochemistry and confocal microscopy in situ, ADAMTS5 expression is confined to proliferating glioblastoma cells of surgical tumor sections and with lower intensity to astroglial cells in normal brain sections, as opposed to brevican. In vitro, glioblastoma‐derived ADAMTS5 degrades recombinant human brevican to several smaller fragments. Our results show that ADAMTS4 and 5 are upregulated on proliferating glioblastoma cells and these proteases may contribute to their invasive potential. © 2005 Wiley‐Liss, Inc.
Cisplatin‐dependent upregulation of death receptors 4 and 5 augments induction of apoptosis by TNF‐related apoptosis‐inducing ligand against esophageal squamous cell carcinoma
Authors: Kondo Kan , Yamasaki Seiji , Sugie Tomoharu , Teratani Naoki , Kan Takatsugu , Imamura Masayuki , Shimada Yutaka
Published: July 2005

TNF‐related apoptosis‐inducing ligand (TRAIL) is a member of the TNF superfamily known to induce apoptosis in a variety of cancers. The purpose of our study was to examine the effects of TRAIL in combination with cisplatin against esophageal squamous cell carcinoma (ESCC) cell lines in vitro and in vivo, and to elucidate underlying molecular mechanisms. Expression profiles of TRAIL receptors were investigated in 19 ESCC (KYSE) cell lines using RT‐PCR. Crystal violet staining assays were performed to reveal the sensitivity against TRAIL. Flow cytometric analyses of apoptosis induction and TRAIL receptor expression were performed. Furthermore, Western blot was used to clarify the apoptosis pathway involved, and a nude‐mouse xenograft model was used to show effects in vivo. Results show that death receptors (DR) 4 and 5 were expressed in 100% of the cell lines, and 79% (15/19) expressed 4 TRAIL receptors. There was only 1 cell line without decoy receptor expression. Eighteen cell lines were resistant to TRAIL, but in some, the combination treatment with cisplatin could overcome this resistance. They underwent apoptosis via activation of caspase‐8 and ‐3, and cisplatin‐dependent upregulation of DR4 and 5 was detected. Furthermore, pretreatment with cisplatin followed by TRAIL resulted in significant tumoricidal effects. Finally, systemic administration of TRAIL with cisplatin synergistically suppressed tumor growth of ESCC xenografts in nude mice. These results provide a significance of cisplatin‐induced upregulation of death receptors as apoptosis‐inducing machinery, and it was suggested that sequential administration of cisplatin and TRAIL might be a feasible chemotherapeutic regimen against ESCC. © 2005 Wiley‐Liss, Inc.
Gender‐specific polygenic control of ethylnitrosourea‐induced oncogenesis in the rat peripheral nervous system
Authors: Koelsch Bernd U. , Fischer Christine , Neibecker Markus , Schmitt Nina , Schmidt Ortrud , Rajewsky Manfred F. , Kindler‐Röhrborn Andrea
Published: July 2005

The inbred BD rat strains constitute a model system for analysis of the genetic basis of susceptibility or resistance to the development of neural tumors, as they exhibit distinct strain‐specific differences regarding the sensitivity to tumor induction by the alkylating carcinogen N‐ethyl‐N‐nitrosourea (EtNU). Among the different BD strains, BDIX and BDIV rats, respectively, are either highly susceptible or entirely resistant to the development of EtNU‐induced malignant schwannomas of the peripheral nervous system (PNS), predominantly of the trigeminal nerves. We have previously mapped one locus associated with susceptibility/resistance to schwannoma induction to the telomeric third of chromosome 10 (Mss1) in segregating (BDIX × BDIV) crosses. We report on the genetic mapping of 6 further loci controlling tumor incidence or survival time on chromosomes 1 (Mss2), 3 (Mss3), 6 (Mss4), 13 (Mss5) and 15 (Mss6) as well as on chromosome 10 (Mss7) close to the centromere. Interestingly, most of these loci mediate gender‐specific effects of variable strength ranging from minor influences on tumor development to complete tumor resistance. The gender specificity is reflected by the fact that male (BDIX × BDIV) F2 rats exhibit a 2‐fold higher incidence of EtNU‐induced schwannomas than females as well as a shorter survival time. A number of human nervous system tumors too arise with a marked gender bias. Genes mediating gender‐specific predisposition of developing malignant schwannomas in the rat may be relevant for the human individual risk of developing nervous system tumors. © 2005 Wiley‐Liss, Inc.
Targeted chemotherapy with cytotoxic bombesin analogue AN‐215 inhibits growth of experimental human prostate cancers
Authors: Stangelberger Anton , Schally Andrew V. , Letsch Markus , Szepeshazi Karoly , Nagy Attila , Halmos Gabor , Kanashiro Celia A. , Corey Eva , Vessella Robert
Published: July 2005

We developed a powerful cytotoxic analogue of bombesin AN‐215, in which the bombesin (BN)‐like carrier peptide is conjugated to 2‐pyrrolino doxorubicin (AN‐201). Human prostate cancers express high levels of receptors for BN/gastrin releasing peptide (GRP) that can be used for targeted chemotherapy. The effects of targeted chemotherapy with cytotoxic BN analogue AN‐215 were evaluated in nude mice bearing subcutaneous xenografts of DU‐145, LuCaP‐35, MDA‐PCa‐2b and intraosseous implants of C4‐2 human prostate cancers. Intraosseous growth of C4‐2 tumors was monitored by serum PSA. BN/GRP receptors were evaluated by 125I‐[Tyr4]BN binding assays and RT‐PCR. The effects of AN‐215 on apoptosis and cell proliferation were followed by histology, and the expression of Bcl‐2 and Bax protein was determined by Western blot analysis. Targeted analog AN‐215 significantly inhibited growth of subcutaneously implanted DU‐145, LuCaP‐35 and MDA‐PCa‐2b prostate cancers by 81% to 91% compared to controls, while cytotoxic radical AN‐201 was less effective and more toxic. Serum PSA levels of mice bearing intraosseous C4‐2 prostate tumors were significantly reduced. In LuCaP‐35 tumors administration of BN antagonist RC‐3095 prior to AN‐215 blocked the receptors for BN/GRP and inhibited the effects of AN‐215. High affinity receptors for BN/GRP and their m‐RNA were detected on membranes of all 4 tumor models. Therapy with AN‐215, but not with AN‐201, decreased the ratio of Bcl‐2/Bax in DU‐145 and the expression of antiapoptotic Bcl‐2 in LuCaP‐35 tumors. The presence of BN/GRP receptors on primary and metastatic prostate cancers makes possible targeted chemotherapy with AN‐215 for the treatment of this malignancy. © 2005 Wiley‐Liss, Inc.
Supraagonistic, bispecific single‐chain antibody purified from the serum of cloned, transgenic cows induces T‐cell‐mediated killing of glioblastoma cells in vitro and in vivo
Authors: Grosse‐Hovest Ludger , Wick Wolfgang , Minoia Rosa , Weller Michael , Rammensee Hans‐Georg , Brem Gottfried , Jung Gundram
Published: July 2005

Here we characterize the antitumor activity of a recombinant bispecific single‐chain antibody isolated from the serum of cloned transgenic cows. The antibody, termed r28M, is directed to a melanoma‐associated proteoglycan, also expressed on glioblastoma cells, and to human CD28. Bound to tumor cells, r28M induced exceedingly efficient supraagonistic T‐cell activation via the CD28 molecule without an additional stimulus via the TCR/CD3 complex. In vitro, T cells and NK cells contributed to tumor cell killing after r28M‐mediated activation of peripheral blood mononuclear cells. However, NK activity depended on T‐cell‐derived cytokines. In vivo, r28M markedly inhibited the growth of human glioblastoma cells in nude mice. The serum half‐life of the protein after i.v. injection was approximately 6 hr. Thus, r28M is unique not only in inducing supraagonistic CD28‐mediated T‐cell activation against tumor cells in vitro and in vivo, it also meets 2 additional requirements that are critical for clinical application: a relatively long serum half‐life and the possibility of obtaining large amounts of active material from cloned transgenic livestock. © 2005 Wiley‐Liss, Inc.
NAT2 slow acetylation and bladder cancer in workers exposed to benzidine
Authors: Carreón Tania , Ruder Avima M. , Schulte Paul A. , Hayes Richard B. , Rothman Nathaniel , Waters Martha , Grant Delores J. , Boissy Robert , Bell Douglas A. , Kadlubar Fred F. , Hemstreet George P. , Yin Songnian , LeMasters Grace K.
Published: July 2005

This study expands a previous study of NAT2 polymorphisms and bladder cancer in male subjects occupationally exposed only to benzidine. The combined analysis of 68 cases and 107 controls from a cohort of production workers in China exposed to benzidine included 30 new cases and 67 controls not previously studied. NAT2 enzymatic activity phenotype was characterized by measuring urinary caffeine metabolite ratios. PCR‐based methods identified genotypes for NAT2, NAT1 and GSTM1. NAT2 phenotype and genotype data were consistent. A protective association was observed for the slow NAT2 genotype (bladder cancer OR = 0.3; 95% CI = 0.1 = 1.0) after adjustment for cumulative benzidine exposure and lifetime smoking. Individuals carrying NAT1wt/*10 and NAT1*10/*10 showed higher relative risks of bladder cancer (OR = 2.8, 95% CI = 0.8–10.1 and OR = 2.2, 95% CI = 0.6–8.3, respectively). No association was found between GSTM1 null and bladder cancer. A metaanalysis risk estimate of case‐control studies of NAT2 acetylation and bladder cancer in Asian populations without occupational arylamine exposures showed an increased risk for slow acetylators. The lower limit of the confidence interval (OR = 1.4; 95% CI = 1.0–2.0) approximated the upper confidence interval for the estimate obtained in our analysis. These results support the earlier finding of a protective association between slow acetylation and bladder cancer in benzidine‐exposed workers, in contrast to its established link as a risk factor for bladder cancer in people exposed to 2‐naphthylamine and 4‐aminobiphenyl. Study findings suggest the existence of key differences in the metabolism of mono‐ and diarylamines. Published 2005 Wiley‐Liss, Inc.
Prospective study of dietary acrylamide and risk of colorectal cancer among women
Authors: Mucci Lorelei A. , Adami Hans‐Olov , Wolk Alicja
Published: July 2005

There has been considerable discourse about whether exposure to acrylamide in foods could increase the risk of human cancer. Acrylamide is classified as a probable human carcinogen, and animal studies have demonstrated an increased incidence of tumors in rats exposed to very high levels. Still, epidemiologic data of the effect of dietary acrylamide remain scant. We have undertaken the first prospective study of acrylamide in food and risk of colon and rectal cancers using prospective data from the Swedish Mammography Cohort. The cohort comprised 61,467 women at baseline between 1987 and 1990. Through 2003, the cohort contributed 823,072 person‐years, and 504 cases of colon and 237 of rectal cancer occurred. Mean intake of acrylamide through diet was 24.6 μg/day (Q25–70 = 18.7–29.9). Coffee (44%), fried potato products (16%), crisp bread (15%) and other breads (12%) were the greatest contributors. After adjusting for potential confounders, there was no association between estimated acrylamide intake and colorectal cancer. Comparing extreme quintiles, the adjusted relative risks (95% CI; p for trend) were for colorectal cancer 0.9 (0.7–1.3; p = 0.80), colon cancer 0.9 (0.6–1.4; p = 0.83) and rectal cancer 1.0 (0.6–1.8; p = 0.77). Furthermore, intake of specific food items with elevated acrylamide (e.g., coffee, crisp bread and fried potato products) was not associated with cancer risk. In this large prospective study, we found no evidence that dietary intake of acrylamide is associated with cancers of the colon or rectum. Epidemiologic studies play an important role in assessing the possible health effects of acrylamide intake through food. © 2005 Wiley‐Liss, Inc.
Novel strategy for optimal sequential application of clinical criteria, immunohistochemistry and microsatellite analysis in the diagnosis of hereditary nonpolyposis colorectal cancer
Authors: Engel Christoph , Forberg Jochen , Holinski‐Feder Elke , Pagenstecher Constanze , Plaschke Jens , Kloor Matthias , Poremba Christopher , Pox Christian P. , Rüschoff Josef , Keller Gisela , Dietmaier Wolfgang , Rümmele Petra , Friedrichs Nicolaus , Mangold Elisabeth , Buettner Reinhard , Schackert Hans K. , Kienle Peter , Stemmler Susanne , Moeslein Gabriela , Loeffler Markus ,   the German HNPCC Consortium
Published: July 2005

Clinical criteria, microsatellite analysis (MSA) and immunohistochemistry (IHC) are important diagnostic tools for identification of hereditary nonpolyposis colorectal cancer (HNPCC) patients who are likely to carry pathogenic germline mutations in mismatch repair genes. Based on MSA and IHC results and subsequent mutation analyses of 1,119 unrelated index patients meeting the Amsterdam II criteria or the classical Bethesda guidelines, we analyzed the value of these tools to predict MLH1 and MSH2 mutations with the aim of establishing optimal strategies for their most efficient sequential use. The overall prevalence of pathogenic germline mutations in our cohort was 20.6% (95% CI = 18.3–23.0%) and 61.8% (95% CI = 56.8–66.6%), respectively, after MSA/IHC‐based preselection. IHC was highly predictive (99.1%) and specific (99.6%) with regard to MSA. However, 14 out of 230 mutations (6%) escaped detection by IHC. Thus, IHC cannot be recommended to substitute MSA fully. Nonetheless, IHC is important to indicate the gene that is likely to be affected. To combine both methods efficiently, we propose a novel screening strategy that provides 2 alternative ways of sequential IHC and MSA application, either using IHC or MSA in the first place. A logistic regression model based on the age of the index patient at first tumor diagnosis and the number of fulfilled HNPCC criteria is used to allocate individual patients to that alternative pathway that is expected to be least expensive. A cost analysis reveals that about 25% of the costs can be saved using this strategy. © 2005 Wiley‐Liss, Inc.
Migration of Additives in Polymer Coatings: Phosphonated Additives and Poly(vinylidene chloride)‐Based Matrix
Authors: Rixens Bérengère , Severac Romain , Boutevin Bernard , Lacroix‐Desmazes Patrick , Hervaud Yves
Published: July 2005

Summary: The living radical terpolymerization of vinylidene chloride (VC2), methyl acrylate (MA), and dimethyl‐2‐methacryloxyethylphosphonate (MAPHOS) was performed at 70 °C in benzene by a reversible addition fragmentation chain transfer (RAFT) process to yield a gradient terpolymer of controlled molecular weight ($\overline M _{\rm n}$ = 5 800 g · mol−1, Ip = 1.53) with a molar composition of 75:14:11 (VC2/MA/MAPHOS). Such terpolymers, hydrolyzed (phosphonic acid groups) or not, were used as polymeric additives in coating formulations based on a poly(VC2‐co‐MA) copolymer matrix ($\overline M _{\rm n}$ = 63 300 g · mol−1, Ip = 1.99, VC2/MA = 80:20 molar ratio). The formulations were spun cast on stainless steel surfaces and the coatings were observed by scanning electron microscopy (SEM) coupled with X‐ray analyses (EDX). The hydrolyzed additive was shown to both segregate and migrate towards the metal interface, leading to a preferential organization of the coating. Hence, the matrix at the air surface acts as a barrier to gas while the additive ensures adhesion at the polymer/metal interface.

SEM photograph of a section of the coating with formulation 4 [poly(VC2‐co‐MA‐co‐MAPHOS(OH)2) (75:14:11)].

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SEM photograph of a section of the coating with formulation 4 [poly(VC2‐co‐MA‐co‐MAPHOS(OH)2) (75:14:11)].
Interaction of Surfactant and Initiator Types in Emulsion Polymerisations: A Comparison of Ammonium Persulfate and Hydrogen Peroxide
Authors: Boutti Salima , Zafra Rocio Diez , Graillat Christian , McKenna Timothy F.
Published: July 2005

Summary: In emulsion polymerisation all the components of the system have an influence on the nucleation mechanisms and colloidal stability, and therefore on the final particle size distribution (PSD). The impact of the nature of the initiator (charged radicals and electrically neutral radicals) and its interaction with the composition of the surfactant system and the radical flux on dp is studied in this paper. It was demonstrated that the influence of the nature of initiator on dp depends on the composition of the surfactant system. No influence of the nature of the initiator on Np (number of particles per litre) or the rate of reaction could be discerned when even trace amounts of anionic surfactant were present. But for surfactant‐free reactions or when non‐ionic surfactant (TN) was used as sole stabiliser, it was not possible to produce stable latex using electrically neutral radicals (in this case, hydroxyl radicals). Finally, the order of the semi‐continuous addition of ascorbic acid (AscA) and of hydrogen peroxide (HPO) was studied. As expected, a significant influence of the order of addition was observed in terms of the radical flux and reaction kinetics. It was demonstrated that one mole of AscA added to HPO provides more free radicals than are obtained when a mole of HPO is added to AscA.

Overall conversion vs. reaction time.

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Overall conversion vs. reaction time.
Study of Polyurethane Formulations Containing Diols Obtained via Glycolysis of Poly(ethylene terephthalate) (PET) by Oligoesters Diols through a Reactive Extrusion Process
Authors: Colomines Gaël , Rivas Florian , Lacoste Marie‐Laure , Robin Jean‐Jacques
Published: July 2005

Summary:The glycolysis of PET by oligoester diols in the presence of zinc acetate was carried out in two successive twin‐screw extruders with total residence times of 4 min and without solvent. These new glycolysates were analyzed and used in polyurethane formulation with a commercial polyol. The reactivity of these formulations was studied. The mechanical properties, thermal and swelling behavior of these polyurethanes were investigated. Mechanical properties are improved with the addition of glycolysate. The thermal behavior is not modified with the addition of glycolysate. The swelling behavior of the material depends on the solvent nature. The addition of glycolysate allows a decrease in material swelling in chloroform but increases this swelling in acetone.

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Gamma Ray Irradiation‐Initiated Copolymerization of a Binary Casting System Involving DPBMIn and Vinylpyrrolidone
Authors: Liu Feng , Wang Zhen , Lü Changli , Gao Lianxun , Ding Mengxian
Published: July 2005

Summary: When initiated by gamma ray irradiation, a series of homogenous binary casting systems composed of bismaleimide oligomer DPBMIn with different chain length and reactive solvent vinylpyrrolidone were capable of copolymerization via radical mechanism to form copolymer resins with crosslinked network. Postcuring was performed by thermal treatment subsequent to gamma ray irradiation. The influences of irradiation dose, postcure, DPBMIn content, and chain length of DPBMIn on mechanical properties, water uptake, and thermal property of copolymer resins were investigated in details. Fracture morphologies of copolymer resins based on different DPBMIn were studied by SEM.

SEM images of the copolymer resins.

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SEM images of the copolymer resins.
Synthesis of Fluorinated Hyperbranched Polymers and Their Use as Additives in Cationic Photopolymerization
Authors: Sangermano Marco , Di Gianni Anna , Bongiovanni Roberta , Priola Aldo , Voit Brigitte , Pospiech Doris , Appelhans Dietmar
Published: July 2005

Summary: A fluorine containing hyperbranched polymer was synthesized by modifying an aromatic‐aliphatic hyperbranched polyester with a semifluorinated alcohol via a Mitsunobu reaction and was subsequently used as an additive in cationic photopolymerization of an epoxy resin. The remaining OH groups of the fluorinated hyperbranched polymer interact with the polymeric carbocation through a chain‐transfer mechanism inducing an increase in the final epoxy conversion. The fluorinated HBP induces modification of bulk and surface properties, with an increase in Tg and surface hydrophobicity already reached at very low concentration. The HBFP additive can, therefore, protect the coatings from aggressive solvents, increases hardness, and allows the preparation of a low energy surface coating.

Synthesis of fluorinated hyperbranched polyester.

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Synthesis of fluorinated hyperbranched polyester.
Asymptotic properties of digit sequences of random numbers
Authors: Stadje Wolfgang
Published: July 2005

We consider several aspects of the relationship between a [0, 1]‐valued random variableXand the random sequence of digits given by itsm‐ary expansion. We present results for three cases: (a) independent and identically distributed digit sequences; (b) random variablesXwith smooth densities; (c) stationary digit sequences. In the case of i.i.d. an integral limit thorem is proved which applies for example to relative frequencies, yielding asymptotic moment identities. We deal with occurrence probabilities of digit groups in the case thatXhas an analytic Lebesgue density. In the case of stationary digits we determine the distribution ofXin terms of their transition functions. We study an associated [0, 1]‐valued Markov chain, in particular its ergodicity, and give conditions for the existence of stationary digit sequences with prespecified transition functions. It is shown that all probability measures induced on [0, 1] by such sequences are purely singular except for the uniform distribution. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Rapid Eco‐Friendly Synthesis of Poly(butylene succinate) by a Direct Polyesterification under Microwave Irradiation
Authors: Velmathi Sivan , Nagahata Ritsuko , Sugiyama Jun‐ichi , Takeuchi Kazuhiko
Published: July 2005

Summary: A rapid and eco‐friendly synthesis of poly(butylene succinate) (PBS) using microwaves was developed in the presence of 1,3‐dichloro‐1,1,3,3‐tetrabutyldistannoxane as catalyst. To determine the optimum conditions, the effect of catalyst concentration, bulk vs. solution polymerization, reaction time, temperature, and stoichiometry of the monomers were studied. Based on the optimum conditions, PBS with a weight‐average molecular weight of 2.35 × 104 was obtained in a short time of 20 min.

Synthesis of poly(butylene succinate) under microwave irradiation.

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Synthesis of poly(butylene succinate) under microwave irradiation.
Novel C60‐Anchored Two‐Armed Poly(tert‐butyl acrylate): Synthesis and Characterization
Authors: Chu Chih‐Chien , Wang Leeyih , Ho Tong‐Ing
Published: July 2005

Summary: A multistep synthetic procedure for preparing novel C60‐anchored two‐armed poly(tert‐butyl acrylate) was developed. First, two‐armed poly(tert‐butyl acrylate) bearing a malonate ester core with well‐controlled molecular weight was synthesized through atom transfer radical polymerization. The effective Bingel reaction between C60 and the well‐defined polymer was then carried out to yield C60‐anchored polymer. GPC, 1H NMR, and UV‐vis spectroscopy indicated that the C60‐anchored polymer was a monosubstituted and ‘closed’ 6,6‐ring‐bridged methanofullerene derivative.

Schematic of a novel C60‐anchored two‐armed polymer.

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Schematic of a novel C60‐anchored two‐armed polymer.
Macromolecular Recognition by Polymer‐Carrying Cyclodextrins: Interaction of a Polymer Bearing Cyclodextrin Moieties with Poly(acrylamide)s Bearing Aromatic Side Chains
Authors: Hashidzume Akihito , Ito Fumitaka , Tomatsu Itsuro , Harada Akira
Published: July 2005

Summary: The interaction of a polymer bearing β‐cyclodextrin moieties (β‐CD polymer) with poly(acrylamide)s bearing aromatic side chains was investigated by viscometry to study the effect of collectivity (i.e., interactions at multi‐sites) in macromolecular recognition. The formation of inclusion complexes at multi‐sites caused a large difference in the size of interpolymer aggregates, even though the difference in association constants for complexation of native β‐CD with guest moieties was not very much large.

Conceptual illustration for interpolymer aggregates of β‐CD polymer with poly(acrylamide)s bearing naphthyl groups substituted on the (a) 1‐ and (b) 2‐positions (see Scheme 1).

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Conceptual illustration for interpolymer aggregates of β‐CD polymer with poly(acrylamide)s bearing naphthyl groups substituted on the (a) 1‐ and (b) 2‐positions (see Scheme 1).
Radical approaches to probe protein structure, folding, and interactions by mass spectrometry
Authors: Maleknia Simin D. , Downard Kevin M.
Published: July 2005

I.Introduction388II.Case for Radicals389III.Radiation and Discharge Radical Sources390IV.Reaction Products: Nature of Amino Acid Modifications391V.Protein Integrity Versus Damage392VI.Reaction Kinetics and Protein Structure Elucidation394VII.Protein Folding: Equilibrium and Time‐Resolved Studies395VIII.Protein Complexes and Assemblies397IX.Conclusions398Acknowledgments399References399This review describes mass spectrometry‐based strategies and investigations to determine protein structure, folding dynamics, and protein‐protein interactions in solution through the use of radical reagents. The radicals are generated in high flux within microseconds from synchrotron radiation and discharge sources, and react with proteins on time scales that are less than those often attributed to structural reorganization and folding. The oxygen‐based radicals generated in aqueous solution react with proteins to effect limited oxidation at specific amino acids throughout the sequence of the protein. The extent of oxidation at these residue markers is highly influenced by the accessibility of the reaction site to the bulk solvent. The extent of oxidation allows protection levels to be measured based on the degree to which a reaction occurs. A map of a protein's three‐dimensional structure is subsequently assembled as in a footprinting experiment. Protein solutions that contain various concentrations of substrates that either promote or disrupt dynamic structural transitions can be investigated to facilitate site‐specific equilibrium and time‐resolved studies of protein folding. The radical‐based strategies can also be employed in the study of protein–protein interactions to provide a new avenue for investigating protein complexes and assemblies with high structural resolution. The urea‐induced unfolding of apomyoglobin and the binding of gelsolin to actin are among the systems presented to illustrate the approach. © 2002 Wiley Periodicals, Inc., Mass Spec Rev 20:388–401, 2001; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mas.10013
Polyolefin Macroradical Properties: A Semiempirical Quantum Chemistry Study
Authors: Shyichuk Alexander , Cysewski Piotr
Published: July 2005

Summary: Semiempirical quantum chemistry simulations have been used to estimate the properties of mid‐chain alkyl radicals of ethylene, propylene and styrene oligomers depending on the chain length. The values of spin density and charge on the radical site proved to be almost unchanged for oligomer radicals having from 2 to 11 repeated units. Bond strength parameters of bonds neighboring the radical site demonstrate stable values starting from pentamers. The reliable inference is that the electron structure of polyethylene, poly(propylene) and polystyrene (PS) macroradicals may be simulated by means of relatively short oligomers. The obtained data indicate clearly that the polystyrene tertiary alkyl radical has noticeably decreased values of both spin and charge onto the radical site as well as very decreased strength of β‐bonds. For that reason the PS tert‐alkyl radical is estimated as that having decreased activity and increased susceptibility to chain scission. The most probable cause is delocalization of the free electron onto the neighboring aromatic ring.

Spin density distribution in tertiary radical of polystyrene.

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Spin density distribution in tertiary radical of polystyrene.
Usefulness of electrodiagnostic techniques in the evaluation of suspected tarsal tunnel syndrome: An evidence‐based review
Authors: Patel Atul T. , Gaines Kenneth , Malamut Richard , Park Tracy A. , Toro David R. Del , Holland Neil
Published: July 2005

This evidence‐based review was performed to evaluate the utility of nerve conduction studies (NCSs) and needle electromyography (EMG) in the diagnosis of tibial neuropathy at the ankle (tarsal tunnel syndrome, TTS). A total of 317 articles on TTS were identified that were published in English from 1965 through April 2002, from the National Library of Medicine MEDLINE database. All articles were reviewed on the basis of six selection criteria. The results of this search revealed that four articles met five or more criteria. All four articles examined the use of electrodiagnostic (EDX) techniques for the evaluation of patients with clinically suspected TTS, and were included in this practice parameter. Each of these four studies was considered to meet Class III level of evidence. NCSs were abnormal in some patients with suspected TTS. Sensory NCSs were more likely to be abnormal than motor NCSs but the actual sensitivity and specificity could not be determined. The sensitivity of needle EMG abnormalities could not be determined. NCSs may be useful for confirming the diagnosis of tibial neuropathy at the ankle, recommendation Level C. Well‐designed studies are needed to evaluate more definitively EDX techniques in TTS. Muscle Nerve, 2005
Benign pineal cysts in children with bilateral retinoblastoma: A new variant of trilateral retinoblastoma?
Authors: Beck Popovic Maja , Balmer Aubin , Maeder Philippe , Braganca Teresa , Munier Francis L.
Published: July 2005

Purpose

Patients with hereditary retinoblastoma (Rb) develop in 4%–8% a malignant midline tumor called trilateral Rb (TRb). We report in this study on benign pineal cysts observed in patients investigated for TRb.

Patients and Methods

Between September 1990 and December 2001, 172 patients were screened for TRb. Ninty‐five had bilateral, 77 unilateral disease. The median age at diagnosis of Rb was 7 months (range 1–26). Treatment included enucleation, local treatment with cryotherapy or photocoagulation, first‐line chemotherapy (CT), thermo‐chemotherapy (TCT), Ruthenium plaque, and, rarely, external beam radiation (EBR).

Results

TRb was found in 5/95 patients (5.3%) with bilateral disease. Interestingly, five other patients (5.3%) presented a pineal cyst on magnetic resonance imaging (MRI). No cysts were recorded in the 77 patients with unilateral disease. This difference was statistically significant (P < 0.05). The median age at diagnosis of the pineal cyst was 26 months (range 16–80), much younger than reported in literature for healthy children. Four of five patients with TRb died of the disease, while all the patients with pineal cysts remained stable and asymptomatic during a median follow‐up of 41 months (range 37–54).

Conclusions

This report describes benign cystic lesions of the pineal gland in patients with hereditary Rb, suggesting a benign variant of TRb. Underlying possible pathogenetic mechanisms are discussed. © 2005 Wiley‐Liss, Inc.
Syntheses of 12‐arm star polymers and star diblock copolymers by nitroxide‐mediated radical polymerization using dendritic dodecafunctional macroinitiators
Authors: Miura Yozo , Dote Hiroyuki
Published: July 2005

Dendritic multifunctional macroinitiators having 12 TEMPO‐based alkoxyamines were prepared by the reaction of a benzyl alcohol having 4 TEMPO‐based alkoxyamines with 1,3,5‐tris[(4‐chlorocarbonyl)phenyl]benzene and 1,3,5‐tris(4‐isocyanatophenyl)benzene. Using the dodecafunctional macroinitiators, TEMPO‐mediated radical polymerizations of styrene (St) were carried out at 120 °C, and 12‐arm star polymers (star‐12) with narrow polydispersities of Mw/Mn = 1.06–1.26 were obtained. To evaluate the livingness for the TEMPO‐mediated radical polymerizations of St, hydrolysis of the ester bonds of the 12‐arm star polymers and subsequent SEC measurements were carried out. Furthermore, using star‐12 as the macroinitiator, TEMPO‐mediated radical polymerization of 4‐vinylpyridine (4‐VP) was carried out, and well‐defined poly(St)‐b‐poly(4‐VP) 12‐arm star diblock copolymers with Mw/Mn = 1.18–1.19 were obtained. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3689–3700, 2005
Modification of surface properties of polyethylene by perfluoropolyether blending
Authors: Puukilainen Esa , Pakkanen Tapani A.
Published: July 2005

The preparation of a stabile blend from thermoplastic polymer and lubricating additive was studied with high density polyethylene (HDPE) and perfluoropolyether (PFPE). PFPE was melt blended within HDPE by injection molding. The chemical composition of the mixtures, the relative amount of PFPE on the surface, and the nature of the surface were studied by three surface sensitive methods: attenuated total reflectance infrared (ATR‐IR) spectroscopy, secondary ion mass spectroscopy (SIMS), and contact angle (CA) measurement. All the blends exhibited improved hydrophobicity. CA and SIMS gave a maximum response when about 2.0 wt % PFPE was added, whereas ATR‐IR spectroscopy gave maximum response for an addition of about 3.0 wt %. No changes in surface properties were observed when samples were reanalyzed about 1–4 months after preparation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2252–2258, 2005
Influence of entanglements on glass transition of atactic polystyrene
Authors: Rong Weiren , Fan Zhongyong , Yu Yin , Bu Haishan , Wang Michael
Published: July 2005

Freeze‐dried samples were prepared from dilute solutions of atactic polystyrene (a‐Ps) in benzene in a concentration range of 1 × 10−1 to 2 × 10−5 g/mL, and their glass transition temperatures (Tg) were determined by differential scanning calorimetry. It was found that below a critical concentration (C), the Tg of samples decreases linearly with decreasing logarithmic concentration of solutions. The freeze‐dried samples were annealed at a constant temperature for various times or at various temperatures for the same period of time. The Tg of samples prepared from solutions of concentration below C was observed to shift to higher temperature with increasing annealing temperature or annealing time, finally approaching that of the bulk sample. Fourier transform infrared (FTIR) spectra of the freeze‐dried samples were determined and were compared with the bulk sample. Significant changes in line width and absorption intensity were observed in the spectra of the freeze‐dried samples, indicating that the packing of segments is in a more dilatant state. During annealing, the packing of segments in the samples gradually approaches that of the bulk sample, diminishing the differences in FTIR spectra between the freeze‐dried sample and the bulk sample. The experimental observations are discussed, and it is assumed that intrachain and interchain entanglements may play an important role in glass transition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2243–2251, 2005
Plasma Spraying of Capillary Porous Coatings: Experiments, Modeling, and Biomedical Applications
Authors: Kalita Vassili I. , Gnedovets Alexey G.
Published: July 2005

Summary: A novel technology of plasma spraying three‐dimensional capillary porous (3DCP) titanium coatings with principally new structures consisting of ridges and cavities has been developed. The surface area of the 3DCP coatings increases in direct proportion to the increase of the thickness of the deposited coating. The process of fabrication of the 3DCP coatings is performed under a sharp incidence angle of the plasma spray on the substrate. This method of spraying is based on the effect of shadow zones arising behind the particles already deposited to the substrate. The influence of the spray angle on the coatings porosity, roughness, and structure was investigated both in experiments using the methods of optical microscopy, SEM, image analysis, and porosimetry, and also by means of three‐dimensional numerical simulations. The value of the porosity of the 3DCP coatings reaches ∼50%, and the widths of the ridges and cavities may be regulated over a wide range, from 5 up to 2 700 µm. It was found that in order to achieve the highest strength characteristics of the porous coating, the ridges must be built‐up of splats with a maximum contact area between them. Low porosity (2–10%) of the internal volume of the ridges allows high values of adhesion and cohesion to be reached. The technology of plasma deposition of porous coatings was applied as a method to improve the functional characteristics of intrabone implants widely used in medicine. Enhanced mechanical parameters and high values of porosity and surface area of titanium 3DCP coatings are favorable for bone tissue growth in and fastening of its connection with an implant. The volume available for bone ingrowth into fabricated titanium 3DCP coatings appeared to be six times greater than the corresponding values for conventional plasma‐sprayed coatings.

Computer images of the coating deposited at an off‐normal spray angle and the corresponding pore network.

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Computer images of the coating deposited at an off‐normal spray angle and the corresponding pore network.
The anti‐HIV cyanovirin‐N domain is evolutionarily conserved and occurs as a protein module in eukaryotes
Authors: Percudani Riccardo , Montanini Barbara , Ottonello Simone
Published: July 2005

A novel protein family homologous to the sugar‐binding antiviral protein cyanovirin‐N (CVN) is described. CVN, an 11‐kDa protein that, by binding to the high‐mannose moiety of certain viral surface glycoproteins, blocks virus entry into target cells, has thus far been identified only in the cyanobacterium Nostoc ellipsosporum. Here we show that CVN belongs to a protein family identified by analysis of transcript sequences deriving from a gene expression profiling study conducted in the truffle Tuber borchii. Members of this family (named CyanoVirin‐N
Homology) are found in filamentous ascomycetes and in the fern Ceratopteris richardii. As revealed by 3D structure‐based searches, all CVNH proteins have a predicted fold that matches the so far unique fold of the cyanobacterial polypeptide. The CVNH domain is a versatile protein module. In ferns and cyanobacteria it is found in secretory proteins. In filamentous ascomycetes it is found in nonsecretory monodomain proteins as well as part of multidomain proteins bearing functionally related modules such as the peptidoglycan and chitin‐binding domain LysM. Transcript abundance data further indicate that the expression of different CVNH forms is modulated in response to nutrient availability. These findings have implications for the understanding of protein–oligosaccharide interaction in fungi and plants, and provide candidate polypeptides to be tested and exploited as antiviral agents. Proteins 2005. © 2005 Wiley‐Liss, Inc.