bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium‐Promoted Carbon Monoxide/Ethylene/Styrene Terpolymerization Reaction: Throwing Light on the Different Reactivity of the Two Alkenes
Authors: Durand Jérôme , Scarel Alessandro , Milani Barbara , Seraglia Roberta , Gladiali Serafino , Carfagna Carla , Binotti Barbara 
Published: August 2006

AbstractThe catalytic behavior of dicationic bis‐chelated PdII complexes, [Pd(NN)2][PF6]2, in the CO/ethylene/styrene terpolymerization reaction is studied in detail. The bidentate N‐donor ligands were chosen among 2,2′‐bipyridine (1), 1,10‐phenanthroline (3), their symmetrically substituted derivatives 2, 4, and 5, and 3‐alkyl‐substituted 1,10‐phenanthrolines 6–10. The effect of several parameters (like temperature, CO/ethylene pressure, styrene content, reaction time) was investigated and related to the productivity of the catalytic system, to the relative content of the two olefins in the polymeric chains, and to the molecular mass of the synthesized polyketones. The presence of 1,4‐benzoquinone was necessary to reach productivities as high as 16 kg of terpolymer (TP) per gram of Pd. 13C‐NMR spectroscopy was useful to characterize the distribution of the two repetitive units along the polymer chain. Terpolymers with prevailingly isolated CO/styrene units in CO/ethylene blocks as well as terpolymers with CO/styrene and CO/ethylene blocks were obtained by varying the reaction conditions. Detailed MALDI‐TOF‐MS analysis was performed on the CO/ethylene/styrene terpolymers for the first time, and it allowed us to characterize the end groups of the terpolymer chains. The presence of different chain end groups was found to be related to the initial amount of the two alkenes, thus suggesting that different reactions are involved in the initiation and termination steps of the terpolymerization catalytic cycle.
Preparation of C2‐Symmetric Bis[2‐(diphenylphosphino)ferrocen‐1‐yl]‐ methane and Its Use in Rhodium‐ and Ruthenium‐Catalyzed Hydrogenation
Authors: Wang Yaping , Weissensteiner Walter , Mereiter Kurt , Spindler Felix 
Published: August 2006

AbstractThe two diphosphine ligands (Rp,Rp)‐ and (Sp,Sp)‐bis[2‐(diphenylphospino)ferrocenyl]methane, (Rp,Rp)‐ and (Sp,Sp)‐1, resp., were prepared in six steps from (S)‐ and (R)‐ferrocenyl tolyl sulfoxide, respectively (Scheme). In the solid state, both the diborane complex (Rp,Rp)‐1 ⋅ (BH3)2 and the palladium dichloride complex [PdCl2((Rp,Rp)‐1)] were found to adopt C2‐pseudosymmetric structures according to X‐ray analyses (Figs. 2 and 3). In the Rh‐ and Ru‐catalyzed hydrogenation of selected alkenes and ketones in the presence of the new ligands, enantioselectivities of up to 55% ee were obtained.
The Methoxycarbonylation of Vinyl Acetate Catalyzed by Palladium Complexes of [1,2‐Phenylenebis(methylene)]bis[di(tert‐butyl)phosphine]
Authors: Rucklidge Adam J. , Morris George E. , Slawin Alexandra M. Z. , Cole‐Hamilton David J. 
Published: August 2006

AbstractPalladium complexes of [1,2‐phenylenebis(methylene)]bis[di(tert‐butyl)phosphine] (1) catalyze the methoxycarbonylation of vinyl acetate (= ethenyl acetate) in the presence of methanesulfonic acid (Scheme 1). High selectivities to ester products can be obtained if free phosphine ligand is in excess over the amount of added acid (Table 1). Selectivities to methyl 2‐acetoxypropanoate, a precursor to lactate esters, can be as high as 3.6 : 1 at low temperature and pressure (Table 2). Replacing tBu by iPr groups leads to less‐active catalysts and lower selectivities to the branched product. Replacing the phenylene moiety by a naphthalenediyl moiety also gives lower activity, but with similar selectivity to the phenylene‐based analogues. Linear hydrocarbon‐chain linkers as the backbone instead of the phenylenebis(methylene) linker leads to poor catalysis, except for a propane‐1,3‐diyl linker, which gives good rates but poor branched selectivity (Table 5). The effect of different reaction conditions on the catalysis is discussed. The syntheses of the new xylene‐based diphosphines 2–5 with one to four iPr groups replacing the tBu groups at the P‐atoms of 1 and of the ligands 6 and 7 based on 1,2‐ and 2,3‐dimethylnaphthalene are also described (Schemes 2 and 3).
The role of cyclophosphamide and granulocyte colony‐stimulation factor in achieving high‐level chimerism in allotransplanted limbs
Authors: Muramatsu Keiichi , You‐Xin Song , Hashimoto Takahiro , Matsunaga Tsunemitsu , Taguchi Toshihiko 
Published: August 2006

AbstractThe establishment of a high‐level of chimerism may be the most stable strategy for donor‐specific tolerance. The purpose of this study was to evaluate the efficacy of a new protocol using cyclophosphamide (CYP) and granulocyte colony‐stimulation factor (G‐CSF) to induce high‐level chimerism following rat whole‐limb allotransplantation. Seventy‐three whole‐limb allotransplants from LacZ transgenic rats to LEW rats were performed. CYP was injected at day 2, and G‐CSF was given from day 0 to 3. Nontreated limb allografts were rejected after 4.2 days. In FK506‐treated group for 28 days, the survival time was prolonged to 64 days. In the group treated with CYP/G‐CSF, limb allografts were rejected after 5.4 days and 5 of 15 recipients showed acute lethal graft‐versus‐host disease (GVHD). Polymerase chain reaction (PCR) study showed a high level of chimerism even within 1 week after transplantation. Fourteen of 30 recipients given CYP/G‐CSF/FK506 died within 2 weeks. The limb survival was significantly prolonged, however, with three grafts surviving more than 300 days. Seven recipients (24%) showed chronic GVHD. A high‐level of chimerism was maintained when limb allografts were not rejected by recipients. Limb allografting could function as a vascularized carrier for bone marrow transplantation, provide a continuous source of donor cells and contribute to a high level of chimerism in the recipient. Pretransplant CYP followed by G‐CSF and FK506 treatment significantly prolonged the survival of limb allografts but frequently caused chronic GVHD in the recipients. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2133–2140, 2006
Regenerative properties of fetal sheep tendon are not adversely affected by transplantation into an adult environment
Authors: Favata Michele , Beredjiklian Pedro K. , Zgonis Miltiadis H. , Beason David P. , Crombleholme Timothy M. , Jawad Abbas F. , Soslowsky Louis J. 
Published: August 2006

AbstractTendon injuries account for a significant number of musculoskeletal afflictions each year. While new surgical techniques and rehabilitation protocols have led to improved clinical outcomes, postsurgical scarring remains the most problematic aspect of tendon repair. In contrast to this typical pattern of fibrosis, recent studies have shown that fetal tendon is capable of healing without scar. However, whether this regenerative healing pattern is intrinsic to the fetal tissue itself or the result of its environment is not known. Thus, the objective of this study is to examine the influence of an adult environment on healing in adult and fetal tendons. We hypothesized that injured fetal tendon tissue transplanted into an adult environment would retain a regenerative healing pattern after injury, demonstrating normal histological and mechanical properties. Our results support this hypothesis. Histological analyses revealed considerable alterations in adult tendon transplants after injury while fetal transplants showed no abnormalities. The injured adult tendons also demonstrated elevated levels of TGF‐β1, bFGF, and CD44 at the wound site, whereas the fetal specimens showed little or no such changes in response to injury. The data from our biomechanical studies further corroborate these observations, with significant decreases in the stiffness, modulus, and almost all viscoelastic properties in wounded versus unwounded adult tendons, and fetal specimens showing no differences in mechanical properties between the wounded and unwounded groups. Thus, the results of our investigation demonstrate that the adult environment is not an impediment to scarless repair and that this capability is intrinsic to the fetal tendon itself. Our study also begins to provide insight into the mechanisms controlling this regenerative response. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2124–2132, 2006
Tephrochronological dating of varved interglacial lake deposits from Piànico‐Sèllere (Southern Alps, Italy) to around 400 ka
Authors: Brauer Achim , Wulf Sabine , Mangili Clara , Moscariello Andrea 
Published: August 2006

AbstractThe sediment record from the Piànico palaeolake in the southern Alps is continuously varved, spans more than 15 500 years, and represents a key archive for interglacial climate variability at seasonal resolution. The stratigraphic position of the Piànico Interglacial has been controversial in the past. The identification of two volcanic ash layers and their microscopic analysis provides distinct marker layers for tephrochronological dating of these interglacial deposits. In addition to micro‐facies analyses reconstructing depositional processes of both tephra layers within the lake environment, their mineralogical and geochemical composition has been determined through major‐element electron probe micro‐analysis on glass shards. Comparison with published tephra data traced the volcanic source regions of the Piànico tephras to the Campanian volcanic complex of Roccamonfina (Italy) and probably the Puy de Sancy volcano in the French Massif Central. Available dating of near‐vent deposits from the Roccamonfina volcano provides a robust tephrochronological anchor point at around 400 ka for the Piànico Interglacial. These deposits correlate with marine oxygen isotope stage (MIS) 11 and thus are younger than Early to Middle Pleistocene previously suggested by K/Ar dating and older than the last interglacial as inferred from macrofloral remains and the geological setting. Copyright © 2006 John Wiley & Sons, Ltd.
Late Quaternary environments, vegetation and agriculture in northern New Zealand
Authors: Horrocks M. , Nichol S. L. , Augustinus P. C. , Barber I. G. 
Published: August 2006

AbstractA sedimentological and plant microfossil history of the Late Quaternary is preserved in two sediment cores from early Polynesian ditch systems on southern Aupouri Peninsula. The study places human activities into a geomorphological and ecological context and allows comparison of natural and anthropogenic effects on two different geological settings: a floodplain and a relatively closed peat swamp. The data fill part of the current gap in the environmental record from northern New Zealand, namely MIS 3 (57k–26k yr BP). There is evidence for an increase in fire frequency in the region after 40k 14C yr BP, suggesting a shift to drier (and cooler) conditions. Pollen records show that conifer‐hardwood forest dominated by podocarps (especially Dacrydium) prevailed prior to Polynesian arrival and deforestation within the last millennium, with Fuscopsora insignificant throughout. Both cores show sections with gaps in deposition or preservation, possible flood‐stripping of peat during the pre‐Holocene and mechanical disturbance by early Polynesians. The identification of prehistoric starch grains and other microremains of introduced Colocasia esculenta (taro) in both cores supports indirect evidence that the ditch systems of far northern New Zealand were used for the extensive cultivation of this crop. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical composition, antinutritional constituents, precaecal crude protein and amino acid digestibility in three unconventional tropical legumes in broilers
Authors: Iyayi Eustace A , Kluth Holger , Rodehutscord Markus 
Published: August 2006

AbstractThree tropical crop seeds, namely Enterolobium cyclocarpum, Mucuna pruriens and Centrosema pubescens, were assessed for their contents of chemical constituents, antinutritional factors (ANFs), crude protein (CP) and amino acid (AA) digestibility. Their meals were incorporated into broiler diets in place of maize starch at two levels (150 and 300 g kg−1). Four hundred and twenty 1‐day‐old broilers were randomly assigned to seven experimental diets on a weight basis and used to determine CP and AA digestibility in the diets and seeds, and performance of the birds. The CP contents were 237, 278 and 252 g kg−1 DM in E. cyclocarpum, M. pruriens and C. pubescens, respectively. Compared to the basal diet, the digestibility of CP and AAs in the diets and seeds was significantly (p < 0.05) reduced at higher level of inclusion of E. cyclocarpum and M. pruriens but increased at higher C. pubescens inclusion. Digestibility of arginine, threonine and lysine in the C. pubescens meal diets was similar to that in the basal diet. Digestibility values of CP and AAs were least in E. cyclocarpum. Aspartic acid was the least and glutamic acid the most digested AA in all the seeds. Among the essential AAs, threonine was the least digested AA, while leucine (in E. cyclocarpum and M. pruriens) and lysine (in C. pubescens) had the highest digestibility with values of 65, 73 and 72%, respectively. Feed intake, body weights and weight gain in the birds were significantly (P < 0.05) reduced in the E. cyclocarpum and M. pruriens diets but increased in the C. pubescens diets compared to the basal diet. Results of the study suggest that, based on the CP content and AA profiles in the seeds, they have potential for poultry feeding. The presence of ANFs, especially in E. cyclocarpum and M. pruriens, however, could be a major limitation in their use in poultry feeding. Copyright © 2006 Society of Chemical Industry
Genomic organization and structure of the 5′‐flanking region of the TEX101 gene: Alternative promoter usage and splicing generate transcript variants with distinct 5′‐untranslated region
Authors: Tsukamoto Hiroki , Takizawa Toshihiro , Takamori Kenji , Ogawa Hideoki , Araki Yoshihiko 
Published: August 2006

AbstractA novel germ cell‐specific antigen, TEX101 (TES101‐reactive protein), was previously identified using a monoclonal antibody directed against mouse testicular cells. TEX101 is specifically located on the plasma membrane of germ cells, and its expression in gonadal organs is sexually dimorphic. To understand the fundamental mechanism directing gene expression, the genomic organization of TEX101 was studied. The gene consists of five translated exons (exons 2–6) and three 5′‐untranslated exons (exon 1a, 1b, and 1c), respectively. TEX101 forms three major transcripts classified by usage of the three 5′‐untranslated exons. One form of TEX101 mRNA is transcribed from exon 1c and spliced to the common acceptor site in exon 2. In the second form of the transcript, exon 1a is spliced to exon 1b and exon 2 in a sequential manner. Splicing from exon 1a to exon 2, arises the third form of transcript. Reverse Transcription (RT)‐polymerase chain reaction (PCR) analysis demonstrated differential expression pattern of the TEX101 transcripts between testis and ovary. Whereas the expression of transcript‐1 is constitutive in male and female gonads, the transcript‐2 and ‐3 are detected only after starting of the spermatogenesis. Luciferase reporter assays using GC‐2spd(ts) cells, a cell line from immortalized mouse testicular cells, showed that the 5′‐flanking sequence of exon 1c has higher promoter activity than exon 1a. Deletion analysis of the chimeric structures indicated that sequences essential to gene expression are present on the 5′‐flanking region between −3186 and +14, where the cluster of five CAAT boxes is located. Taken together, these findings should facilitate an understanding of the regulation of TEX101 expression during gametogenesis. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Optimization of self‐reference thermometry using complex field estimation
Authors: Kuroda Kagayaki , Kokuryo Daisuke , Kumamoto Etsuko , Suzuki Kyohei , Matsuoka Yuichiro , Keserci Bilgin 
Published: August 2006

AbstractReferenceless, or self‐reference, thermometry is a technique for mapping temperature differences in the region of interest (ROI) using the baseline phase estimated by extrapolating the field in the surrounding region for estimation (RFE) and subtracting the estimated baseline from the measured field. In the present work a self‐reference technique based on complex field estimation using 2D polynomials comprising complex‐valued coefficients was proposed and optimized. Numerical simulations with a Gaussian‐profiled phase distribution demonstrated that the ROI radius had to be 2.3–2.5 times the standard deviation (SD) of the Gaussian function in order to keep the error below 8% of the peak phase change. The area ratio between the ROI and the RFE had to be larger than 2.0 to maintain the error level. Based on the simulations, and phantom and volunteer experiments, the complex‐based method with independently optimized polynomial orders for the two spatial dimensions was compared with the phase‐based method using the similar‐order optimization strategy. The complex‐based method appeared to be useful when phase unwrapping was not removed. Otherwise, the phase‐based method yielded equivalent results with less polynomial orders. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Prevalence and risk factors of overactive bladder syndrome in Fuzhou Chinese women
Authors: Zhang Wenju , Song Yanfeng , He Xiaoyu , Huang Huijuan , Xu Bo , Song Jian 
Published: August 2006

AbstractAimsWe randomly sampled a community‐based, healthy population to evaluate the prevalence and associated risk factors of overactive bladder (OAB) syndrome by using the International Continence Society (ICS) definition.MethodsWe randomly sampled 6,066 women (3.0% of registered female residents aged 20 years and older in Fuzhou) and mailed Bristol Female Lower Urinary Tract Symptoms questionnaire for women self‐completion. Women (4,684; 77.2%) with evaluable data were included in this study.ResultsThe prevalence of OAB was 8.0% (n = 377), OABdry 2.4% (n = 114), and OABwet 5.6% (n = 263), hence 30% had OABdry and 70% OABwet. The prevalence of OAB and OABwet demonstrated an significant increasing with advancing age (P < 0.01). A multiple logistic regression analysis showed menopause, parity >2, constipation, episiotomy, and higher BMI were potential risk factors for OAB, constipation increased the occurrence of OABdry. OABwet was associated with menopause, parity >2, higher fetal birthweight, episiotomy, while cesarean delivery protected against the development of OABwet.ConclusionsThe prevalence of OAB in chinese women is lower than that of most reports in Occidental women, and increases with advancing age. Many potential risk factors increase the occurrence of OAB. Neurourol. Urodynam. 25:717–721, 2006. © 2006 Wiley‐Liss, Inc.
An improved deniable authentication protocol
Authors: Shao Jun , Cao Zhenfu , Lu Rongxing 
Published: August 2006

AbstractDeniable authentication, which was introduced to realize secure online negotiation, has been an extensive topic of research. Wang et al. proposed an efficient deniable authentication protocol based on ElGamal cryptography. However, in this article, we show that Wang et al.'s protocol (WLT protocol) is vulnerable to the person‐in‐the‐middle (PIM) attack. An adversary who launches a PIM attack can impersonate a valid user to communicate with the verifier, which will eventually lead to the failure of an online negotiation. To mitigate this security breach, we propose an improved deniable authentication protocol based on Wang et al.'s scheme. Further, a detailed security analysis is conducted to verify the proposed scheme. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(4), 179–181 2006
The shortest path problem on large‐scale real‐road networks
Authors: Klunder G.A. , Post H.N. 
Published: August 2006

AbstractThe computation of shortest paths between different locations on a road network appears to be a key problem in many applications. Often, a shortest path is required in a very short time. In this article, we try to find an answer to the question of which shortest path algorithm for the one‐to‐one shortest path problem runs fastest on a large real‐road network. An extensive computational study is presented, in which six existing algorithms and a new label correcting algorithm are implemented in several variants and compared on the real‐road network of The Netherlands. In total, 168 versions are implemented, of which 18 versions are variants of the new algorithm and 60 versions are new by the application of bidirectional search. In the first part of the article we present a mathematical framework and a review of existing algorithms. We then describe combinations of existing algorithms with bidirectional search and heuristic‐estimate techniques based on Euclidean distance and landmarks. We also present some useful static reduction techniques. In the final part of the article we present results from computational tests on The Netherlands road network. The new algorithm, which combines concepts from previous work on buckets and label‐correcting techniques, has generally the shortest running times of any of the tested algorithms. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(4), 182–194 2006
The Middle Byzantine menu: palaeodietary information from isotopic analysis of humans and fauna from Kastella, Crete
Authors: Bourbou C. , Richards M. P. 
Published: August 2006

AbstractWe report here on the measurements of carbon and nitrogen stable isotopes of bone collagen from the Middle Byzantine site of Kastella, in the city of Heraklion, on the island of Crete, Greece. The data derived from the analysis suggest a diet based primarily on terrestrial, C3 protein, probably from animal sources, with the inclusion of some marine protein. The adult diet at this site is relatively uniform, with no detectable differences between average isotopic values for males and females. We also found that bone collagen δ15N values for a small number of juveniles decreased to adult levels after the age of two years, indicating that weaning occurred at or before this age. Copyright © 2006 John Wiley & Sons, Ltd.
Histological study of compact bone tissue in some mammals: a method for species determination
Authors: Martiniaková M. , Grosskopf B. , Omelka R. , Dammers K. , Vondráková M. , Bauerová M. 
Published: August 2006

AbstractThe purpose of this investigation was to study compact bone tissue microstructure of some mammals in terms of qualitative and quantitative characteristics, with an emphasis on finding an adequate identification key. Altogether, 36 femora of adult pigs, cows, sheep and rabbits were analysed. The qualitative characteristics were examined according to the classification systems of Enlow & Brown (1956) and Ricqlès et al. (1991) in anterior, posterior, medial and lateral views of thin sections. The quantitative characteristics were assessed using the specific software Scion Image (Scion Corporation, US). We measured area, perimeter, and minimum and maximum diameter of the Haversian canals, the secondary osteons and the vascular canals of primary osteons. The observed data were first used to evaluate inter‐ and intra‐species diversity. After that a discriminant function analysis was used for species determination. According to our results the basic structural pattern of the bone tissue was primary vascular plexiform in pigs, cows and sheep. We found dense Haversian bone tissue in all species. In addition, non‐vascular bone tissue was identified in cows and/or primary vascular longitudinal tissue in rabbits. Many resorption lacunae were found between secondary osteons in pigs. The irregular Haversian bone tissue was localised at the periosteal and endosteal borders in sheep. Classification functions for all investigated species gave a correct classification in 73.83% of cases. The most discriminating variables for the compact bone tissue appeared to be perimeter and minimum diameter of primary osteon's vascular canals. The percentage value can be increased by integrating conclusions from the qualitative analysis. Copyright © 2006 John Wiley & Sons, Ltd.