bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aggregation of [Cu${{\bf }{{{\bf II}\hfill \atop \bf 4\hfill}}}$] Building Blocks into [Cu${{\bf }{{{\bf II}\hfill \atop \bf 8\hfill}}}$] Clusters or a [Cu${{\bf }{{{\bf II}\hfill \atop \bf 4\hfill}}}$]∞ Chain through Subtle Chemical Control
Authors: Aromí Guillem , Ribas Joan , Gamez Patrick , Roubeau Olivier , Kooijman Huub , Spek Anthony L. , Teat Simon , MacLean Elizabeth , Stoeckli‐Evans Helen , Reedijk Jan 
Published: November 2004

AbstractCoordination complexes of the ligand H3L [1,3‐bis(3‐oxo‐3‐phenylpropionyl)‐2‐hydroxy‐5‐methylbenzene] with CuII are reported. Clusters showing various nuclearities or modes of supramolecular organization have been prepared by slightly changing the reaction conditions and have been crystallographically characterized. The reaction of H3L with one equivalent of Cu(OAc)2 in DMF yields the dinuclear complex [Cu2(HL)2(dmf)2] (1). Reaction in MeOH of H3L with an increased amount of metal, in the form of Cu(NO3)2, and excess strong base (nBu4NOH) affords the cluster [Cu8(L)2(OMe)8(NO3)2] (2). Complex 2 is a dimer of two linear [Cu4] arrays bridged by methoxide ligands, where the polynucleating ligand is fully deprotonated. The [Cu4]2 clusters are linked to each other by NO3− bridges to form one‐dimensional coordination polymers. The link between [Cu8] units and their relative spatial positioning can be modified by changing the anion of the CuII salt, as demonstrated by the synthesis of the cluster polymers [Cu8(L)2(OMe)8Cl2] (3) and [Cu8(L)(OMe)7.86Br2.14] (4), where only NO3− has been replaced by Cl− or Br−, respectively. Similarly, when ClO4− is used, compound [Cu8(L)2(OMe)8(ClO4)2(MeOH)4] (5) can be isolated. It contains independent [Cu8] units. A slight change in the stoichiometry of the reaction leading to 2 affords the related complex catena‐[Cu4(L)(OMe)3(NO3)2(H2O)0.36] (6). This polymer contains essentially the same [Cu4] moiety as 2, albeit organized in a completely different arrangement. Each [Cu4] unit in 6 is linked by OMe− ligands to two such equivalent groups to form an infinite chain. Magnetic susceptibility measurements reveal weak antiferromagnetic exchange between CuII centers in 1 (J = −0.73 cm−1) and strong antiferromagnetic coupling within [Cu4] chains in 2, 5, and 6 (most negative J values of −113.8 and −177.3 cm−1 for 2 and 6, respectively).
Signal integration of metastable information communication system and its limitation
Authors: Ishiwata Junya , Kondo Michimasa , Fujisaka Takahiko 
Published: November 2004

AbstractThis paper considers the concept of an MSCS (metastable information communications system) for remote transmission of measured data with gradual variations of the transmission frame cycle and proposes a signal integration method for improvement of the transmission characteristics. Based on the proposed method, a signal integration algorithm for a system remotely transmitting measured sensor data from on board a moving body is derived. An improvement of the received SNR (signal‐to‐noise ratio) is demonstrated by simulation. As a specific example, the integration effect and limitation of the number of integrations determined by the relationship between the error ellipse and the speed of movement is derived with a GPS as a measurement sensor. An example result includes a maximum of 7 integrations for an allowable error of ±16 m for the GPS sensor measurement, a frame period of 1 s, and a speed of movement of 2.5 m/s, with the bit error rate improved by 8 dB when the input SNR is 0 dB. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(3): 44–52, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20154
Effect of nucleotide excision repair on ENU‐induced mutation in female germ cells of Drosophila melanogaster
Authors: Álvarez L. , Comendador M.A. , Sierra L.M. 
Published: November 2004

AbstractThe role of nucleotide excision repair (NER) in the repair of alkylation damage in the germ cells of higher eukaryotes has been studied mainly by treating postmeiotic male germ cells. Little is known about repair in actively repairing female germ cells. In this study, we treated NER‐deficient (ner‐) mus201D1 Drosophila females with N‐ethyl‐N‐nitrosourea (ENU) and determined both the mutant frequencies in the multiple locus recessive lethal (RL) test and in the single locus vermilion gene and determined the ENU mutation spectrum in the vermilion gene. The results show that ENU is mutagenic in all cell stages and that the induced frequencies increase with cell maturation, from oogonia to mature oocytes. In addition, the induced spectrum consists mainly of A:T→T:A transversions (43.8%), A:T→G:C transitions (21.9%), and A:T→C:G transversions (15.6%). G:C→A:T (3.1%) transitions, other transversions (9.4%), frameshifts (3.1%), and deletions (3.1%) were also found. Comparison of these results with those previously obtained for repair‐proficient (ner+) female germ cells reveal: 1) Differences in the RL and vermilion mutation frequencies for ner+ and ner‐ germ cells, indicating that NER is involved in the repair of ENU‐induced damage to these cells. 2) At least 15.6% of mutations in ner‐ cells may be the consequence of N‐ethylation damage and mutations of this type were not detected in ner+ cells. 3) Although differences were found in transition frequencies between ENU‐treated ner+ and ner‐ germ cells (52.2% vs. 25%), suggesting that a functional NER is involved in processing O‐ethylated damage, the role of NER in repairing O‐ethylated adducts is uncertain. Environ. Mol. Mutagen. 41:270–279, 2003. © 2003 Wiley‐Liss, Inc.
E. coli BW535, a triple mutant for the DNA repair genes xth, nth, and nfo, chronically induces the SOS response
Authors: Janion Celina , Sikora (nee Wójcik) Anna , Nowosielska Anetta , Grzesiuk Elżbieta 
Published: November 2004

AbstractA strong chronic induction of the SOS response system occurs in E. coli BW535, a strain defective in nth, nfo and xth genes, and hence severely deficient in the repair of abasic sites in DNA. This was shown here by visualization of filamentous growth of the BW535 strain and by measuring the level of β‐galactosidase expressed in BW535/pSK1002 in comparison to the AB1157/pSK1002 strain. The plasmid pSK1002 bears an umuC::lacZ fusion in which lacZ is under the control of the umuC promoter and regulated under the SOS regulon. Increases in the expression of β‐galactosidase occur in BW535 without any exogenous SOS inducer. Chronic induction of the SOS response was observed previously in E. coli strains bearing mutations in certain genes that have mutator activity and BW535 is a moderate mutator strain. However, not all mutators show this property, since chronic induction of SOS was not observed in mutT or mutY mutators. MutT and MutY proteins, when active, protect bacteria from mutations induced by 8‐oxoG lesions in DNA. This suggests that accumulation of abasic sites, but not 8‐oxoG residues in DNA, induce the SOS response. Environ. Mol. Mutagen. 41:237–242, 2003. © 2003 Wiley‐Liss, Inc.
Flow past a cylinder: shear layer instability and drag crisis
Authors: Singh S. P. , Mittal S. 
Published: November 2004

AbstractFlow past a circular cylinder for Re=100 to 107 is studied numerically by solving the unsteady incompressible two‐dimensional Navier–Stokes equations via a stabilized finite element formulation. It is well known that beyond Re ∼ 200 the flow develops significant three‐dimensional features. Therefore, two‐dimensional computations are expected to fall well short of predicting the flow accurately at high Re. It is fairly well accepted that the shear layer instability is primarily a two‐dimensional phenomenon. The frequency of the shear layer vortices, from the present computations, agree quite well with the Re0.67 variation observed by other researchers from experimental measurements. The main objective of this paper is to investigate a possible relationship between the drag crisis (sudden loss of drag at Re ∼ 2 × 105) and the instability of the separated shear layer. As Re is increased the transition point of shear layer, beyond which it is unstable, moves upstream. At the critical Reynolds number the transition point is located very close to the point of flow separation. As a result, the shear layer eddies cause mixing of the flow in the boundary layer. This energizes the boundary layer and leads to its reattachment. The delay in flow separation is associated with narrowing of wake, increase in Reynolds shear stress near the shoulder of the cylinder and a significant reduction in the drag and base suction coefficients. The spatial and temporal power spectra for the kinetic energy of the Re=106 flow are computed. As in two‐dimensional isotropic turbulence, E(k) varies as k−5/3 for wavenumbers higher than energy injection scale and as k−3 for lower wavenumbers. The present computations suggest that the shear layer vortices play a major role in the transition of boundary layer from laminar to turbulent state. Copyright © 2004 John Wiley & Sons, Ltd.
Gene amplifications in osteosarcoma—CGH microarray analysis
Authors: Atiye Jassu , Wolf Maija , Kaur Sippy , Monni Outi , Böhling Tom , Kivioja Aarne , Tas Éva , Serra Massimo , Tarkkanen Maija , Knuutila Sakari 
Published: November 2004

AbstractLittle is known about the genomic alterations underlying osteosarcoma. We performed a genomewide high‐resolution gene copy number analysis of 22 osteosarcoma samples using comparative genomic hybridization on a cDNA microarray that contained cDNA clones of about 13,000 genes. Nineteen of the 22 cases had amplifications that on average spanned more than 1 Mb and contained more than 10 genes. Numerous regions of gain and loss were identified, and their boundaries were defined at high resolution. Novel amplicons were found at 14q11, 17q25, and 22q11–q13. Earlier‐known large amplified regions were detected at 12q11–q15, 8q24, 6p12–p13, and 17p11–p13 in 8, 6, 5, and 4 of the 22 samples, respectively. Amplification of 12q was observed more frequently (36% of the cases) than previously reported. Previously known small amplicons at 1p34–p36, 1q21, 19q13, and 21q22 were seen in at least three cases. Our results implicate TOM1L2 and CYP27B1 as having roles as novel targets for the 17p and 12q amplicons, respectively. Details (www.helsinki.fi/cmg) of the amplified genes in each amplicon provide valuable raw data for further in silico studies. © 2004 Wiley‐Liss, Inc.
Auxiliary liver transplantation: Regeneration of the native liver and outcome in 30 patients with fulminant hepatic failure-a multicenter European study
Authors: Chenard-Neu M , Boudjema K , Bernuau J , Degott C , Belghiti J , Cherqui D , Costes V , Domergue J , Durand F , Erhard J , De Hemptinne B , Gubernatis G , Hadengue A , Kemnitz J , McCarthy M , Maschek H , Mentha G , Oldhafer K , Portmann B , Praet M , Ringers J , Rogiers X , Rubbia L , Schalm S , Kate F T , Terpstra O , Van Hoek B , Williams R , Zafrani E , Cinqualbre J , Wolf P , Jaeck D , Bellocq J 
Published: November 2004

Auxiliary liver transplantation (LT) is a special procedure of LT which could be proposed to patients with fulminant hepatic failure (FHF) and has for aim that complete regeneration of the native liver (NL) left in place will allow the graft recipient to resume normal liver function after allograft withdrawal.
We report 30 cases of auxiliary LT performed for FHF in 12 European centers. Twenty-five of 30 patients were younger than 50 years. The cause of FHF was hepatitis A virus (HAV) in 4 patients, hepatitis B virus (HBV) in 7, paracetamol overdose in 5, ecstasy in 2, hepatotoxic drugs in 4, autoimmune hepatitis in 2, liver lesions of preeclampsia in 1 and unknown in 5. A postoperative, both clinical and histological follow-up of more than 3 weeks was obtained in 22 patients, enabling us to look for indicators predictive of NL regeneration and outcome. Histological changes observed in the NL included complete regeneration in 68%, incomplete regeneration with obvious fibrous sequelae in 14% and severe liver fibrosis or cirrhosis in 18%, of the 22 patients studied. The percentage and distribution of necrosis observed in tissue samples of the NL at the time of transplantation was not related to the final outcome. Complete NL regeneration was observed in 15 patients, out of whom 14 were younger than 40 years. Patients with complete regeneration were mainly affected by FHF due to HAV, HBV, or paracetamol overdose. After a follow-up of 18/11 (mean/median) months (range, 3 to 67 months), 19 of the 30 patients (63%) survived and 13 of them (68%), i.e., 43% of the 30 patients, had resumed normal NL function, with interrupted immunosuppression, the ultimate goal of emergency auxiliary LT.
We conclude that, in patients with FHF, auxiliary LT is a procedure feasible in a number of centers and is associated with a complete regeneration capability of the NL in a majority of survivors, especially in those younger than 40 years. Confirmation of these encouraging preliminary results by large-scale prospective studies is required.
Postmenopausal levels of sex hormones and risk of breast carcinoma in situ: Results of a prospective study
Authors: Zeleniuch‐Jacquotte Anne , Gu Yian , Shore Roy E. , Koenig Karen L. , Arslan Alan A. , Kato Ikuko , Rinaldi Sabina , Kaaks Rudolf , Toniolo Paolo 
Published: November 2004

AbstractWe report on a prospective study to assess the association of postmenopausal serum levels of sex hormones with subsequent risk of breast carcinoma in situ. We conducted a case‐control study nested within the cohort of the New York University Women's Health Study, a large prospective study documenting a positive association of circulating levels of estrogens and androgens with invasive breast cancer. The study included 69 cases of incident in situ carcinoma and 134 individually matched controls. No statistically significant trend of increasing risk with increasing level of any of the hormones was observed. Odds ratios (95% CIs) for the highest tertile relative to the lowest were 1.10 (0.51–2.39) for estradiol, 0.95 (0.41–2.19) for estrone, 1.63 (0.69–3.88) for testosterone, 0.99 (0.44–2.24) for androstenedione, 0.99 (0.45–2.20) for dehydroepiandrosterone sulfate and 0.81 (0.38–1.74) for sex hormone–binding globulin. Adjusting for potential confounders did not materially affect the results, nor did limiting the analysis to the 59 cases of ductal carcinoma in situ, the lesion thought to be the direct precursor of most invasive breast cancers. Our results are at variance with the positive associations observed in this same cohort with risk of invasive breast cancer. Possible explanations for our results include lack of power, an effect of sex hormones limited to the progression from in situ to invasive tumors, overrepresentation of indolent tumors or an effect of sex hormones on the induction of only a subset of in situ tumors, those that would develop into invasive tumors. © 2004 Wiley‐Liss, Inc.
Active and passive smoking and breast cancer risk in middle‐aged Japanese women
Authors: Hanaoka Tomoyuki , Yamamoto Seiichiro , Sobue Tomotaka , Sasaki Satoshi , Tsugane Shoichiro 
Published: November 2004

AbstractTo examine the hypothesis that tobacco smoke is associated with the risk of female breast cancer, we estimated the relative risks of active and passive smoke in middle‐aged Japanese women in a population‐based prospective study. The cohort consisted of residents in 4 public health center areas, aged 40 to 59 years. A self‐administered questionnaire survey was conducted in 1990. This analysis included 21,805 subjects, 180 of whom had developed breast cancer by December 31, 1999. When the reference was defined as never‐active smokers without passive smoking, adjusted relative risks (RRs) were 1.9 (95% confidence interval [CI] = 1.0–3.6) in current active smokers, 1.2 (95% CI = 0.4–4.0) in ex‐active smokers and 1.2 (95% CI = 0.8–1.6) in never‐active smokers with passive smoking. The elevated risk for ever‐smokers was clearly observed in premenopausal women at baseline (RR = 3.9, 95% CI = 1.5–9.9) but not in postmenopausal women (RR = 1.1, 95% CI = 0.5–2.5). In never‐active smokers, the adjusted RR for passive smoking, residential or occupational/public tobacco smoke exposure was 1.1 (95% CI = 0.8–1.6). In premenopausal women, passive smoking increased the risk (RR = 2.6; 95% CI = 1.3–5.2) but not in postmenopausal women (RR = 0.7; 95% CI = 0.4–1.0). We conclude that tobacco smoking increases the risk of female breast cancer in premenopausal women. © 2004 Wiley‐Liss, Inc.
CXCR4 expression reflects tumor progression and regulates motility of bladder cancer cells
Authors: Retz Margitta M. , Sidhu Sukhvinder S. , Blaveri Ekaterina , Kerr Sheena C. , Dolganov Gregory M. , Lehmann Jan , Carroll Peter , Simko Jeff , Waldman Frederic M. , Basbaum Carol 
Published: November 2004

AbstractTransitional cell carcinoma of the urinary bladder remains life threatening due to the high occurrence of metastases. Emerging evidence suggests that chemokines and their receptors play a critical role in tumor metastases. In our study, we performed a systematic analysis of the mRNA and protein expression levels of all 18 chemokine receptors in normal urothelium and bladder cancer. CXCR4 was the only chemokine receptor whose mRNA expression level was upregulated in bladder cancer cell lines as well as in invasive and locally advanced bladder cancer tissue samples (pT2–pT4). In contrast, superficial bladder tumors (pTa and pT1) displayed low CXCR4 expression levels and normal urothelial cells were negative for CXCR4. Immunohistochemistry of a bladder cancer tissue microarray (TMA) confirmed that a subgroup of invasive bladder cancers revealed a high CXCR4 protein expression, while superficial bladder tumors showed low immunoreactivity. To investigate the functional significance of CXCR4 expression, we performed migration and invasion assays. Exposure of CXCR4‐positive bladder cancer cells to CXCL12 in a Boyden chamber type assay provoked a significant increase in migration as well as invasion across a Matrigel barrier. Enhanced migration and invasion were inhibited by a CXCR4‐specific blocking antibody. In contrast, normal urothelial cells did not respond to CXCL12 and lacked chemotactic migration. In conclusion, bladder cancer cells express CXCR4 progressively with advanced tumorigenesis and this receptor interacts with CXCL12 to mediate tumor chemotaxis and invasion through connective tissue. These properties identify CXCR4 as a potential target for the attenuation of bladder cancer metastases. © 2004 Wiley‐Liss, Inc.
Osteosarcoma cell lines display variable individual reactions on wildtype p53 and Rb tumour‐suppressor transgenes
Authors: Hellwinkel Olaf J. C. , Müller Jürgen , Pollmann Annika , Kabisch Hartmut 
Published: November 2004

AbstractBackgroundOne of the most widely studied gene therapeutic strategies for cancer is the introduction of tumour‐suppressor genes—generally p53—into the target cells. As the genes of p53 and/or retinoblastoma (Rb) are mutated in the major part of osteosarcomas (OS), we aimed to study the effect of p53 and Rb transgenes on a panel of five different osteosarcoma cell lines.MethodsOS cell lines were transduced by adenoviral vectors delivering the transcription units of the wildtype p53 and the Rb gene. Effects of the transgenes alone and at additional cytostatic stress were studied by proliferation, alive/dead and cell cycle assays.ResultsThe individual cells lines displayed divergent reactions to p53‐ or Rb‐transgene delivery reaching from cell death (SaOs‐2, U2OS at p53 transduction) over stopped or lowered cell division (MG‐63, K‐HOS, SJSA‐1 at p53 and Rb transduction) to nearly unhindered cell growth (U2OS at Rb transduction). In those OS cell lines reacting with lowered cell division to p53 or Rb delivery, cytostatics only moderately intensified the transgene effects. Surprisingly, these reactions were apparently not dependent on the functional status of the cellular p53 and/or Rb genes or on differences in the infectability of the cell lines by the adenoviral vectors. Most interestingly, the respective effects of the p53 or Rb transgenes were not multiplied by simultaneous transduction of both tumour‐suppressor genes.ConclusionsThe application of wildtype tumour‐suppressor gene therapy on genetically variable osteosarcomas may be efficient only in yet not identified genetic subgroups of this tumour entity. Hyperactive tumour‐suppressor transgenes could be an alternative. Copyright © 2004 John Wiley & Sons, Ltd.
Polystyrene/Montmorillonite Nanocomposites Prepared by In Situ Intercalative Polymerization: Influence of the Surfactant Type
Authors: Essawy Hisham A. , Badran Ahmed S. , Youssef Ahmed M. , Abd El‐Hakim Abou El‐Fettouh A. 
Published: November 2004

AbstractSummary: Na‐montmorillonite (MMT) with a cation exchange capacity (CEC) of 90 meq/100 g was converted to MMT‐CTAB and MMT‐CPC by the intercalation of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC), respectively. The intercalation of CPC onto the basal space of the montmorillonite expanded the basal space from 12.19 to 21.47 Å, whereas in the case of CTAB, the spacing was only expanded to 19.35 Å. The MMT‐CPC and MMT‐CTAB forms were subsequently used as hosts for the preparation of polystyrene nanocomposites via intercalative free‐radical polymerization of styrene. Different structures were obtained by varying the preparation conditions; the exfoliated and intercalated nanocomposites were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and differential scanning calorimeter (DSC). The produced nanocomposites exhibited improved thermal stability in comparison with that of pure polystyrene above 400 °C especially in the case of the nanocomposites based on the MMT‐CPC, in which intercalation exists. A glass transition temperature (Tg) could not be detected for the prepared nanocomposites using DSC; this was assumed to result from the restricted molecular motion of the polymer chains.XRD pattern of PS nanocomposites prepared by intercalative polymerization.magnified imageXRD pattern of PS nanocomposites prepared by intercalative polymerization.
Systematic survey on the prevalence of genes coding for staphylococcal enterotoxins SElM, SElO, and SElN
Authors: Becker Karsten , Friedrich Alexander W. , Peters Georg , von Eiff Christof 
Published: November 2004

AbstractStaphylococcus aureus remains a leading cause of food‐poisoning with substantial impact on public health. Using a multiplex polymerase chain reaction‐DNA enzyme immunoassay (PCR‐DEIA), we studied the presence of genes encoding staphylococcal enterotoxin‐like (SEl) superantigens sem, sen, and seo, associated with the enterotoxin gene cluster (egc), in 429 clinical Staphylococcus aureus isolates. 294 (68.5%) isolates tested positive for at least one of the three SEl genes. In contrast to the fixed gene combination seg/sei also located on egc, a substantial number of isolates (n = 108) were found to bear only one or two of the genes encoding SElM, SElN, and SElO. Regarding the origin of the S. aureus isolates, a significant difference (P = 0.022) was found for the possession of seo (61.2% of blood isolates versus 42.9% of nasal strains). Also sem (not significantly) was found more common in blood isolates (52.1% versus 40.5%). The survey of the newly described SEl genes sem‐seo supports the concept that most clinical S. aureus isolates harbor subsets of pyrogenic toxin superantigens. The potential contribution of seo and sem to the pathogenic potential of S. aureus has to be further evaluated.