bluuebunny/crossref_metadata_2025 huggingface dataset:
Raf-1 kinase mediates adenylyl cyclase sensitization by TNF-α in human airway smooth muscle cells
Authors: Osawa Yoko , Yim Peter D. , Xu Dingbang , Panettieri Reynold A. , Emala Charles W.
Published: February 2007

Tumor necrosis factor (TNF)-α is a potent inflammatory cytokine implicated in the exacerbation of asthma. Chronic exposure to TNF-α has been reported to induce G protein-coupled receptor desensitization, but adenylyl cyclase sensitization, in airway smooth muscle cells by an unknown mechanism. Cyclic AMP, which is synthesized by adenylyl cyclases in response to G protein-coupled receptor signals, is an important second messenger involved in the regulation of the airway muscle proliferation, migration, and tone. In other cell types, TNF-α receptors transactivate the EGF receptor, which activates raf-1 kinase. Further studies in transfected cells show that raf-1 kinase can phosphorylate and activate some isoforms of adenylyl cyclase. Cultured human airway smooth muscle cells were treated with TNF-α in the presence or absence of inhibitors of prostaglandin signaling, protein kinases, or Gi proteins. TNF-α caused a significant dose- (1–10 ng/ml) and time-dependent (24 and 48 h) increase in forskolin-stimulated adenylyl cyclase activity, which was abrogated by pretreatment with GW5074 (a raf-1 kinase inhibitor), was partially inhibited by an EGF receptor inhibitor, but was unaffected by pertussis toxin. TNF-α also increased phosphorylation of Ser338 on raf-1 kinase, indicative of activation. IL-1β and EGF sensitization of adenylyl cyclase activity was also sensitive to raf-1 kinase inhibition by GW5074. Taken together, these studies link two signaling pathways not previously characterized in human airway smooth muscle cells: TNF-α transactivation of the EGF receptor, with subsequent raf-1 kinase-mediated activation of adenylyl cyclase.
Setting the Bar in Phase II Trials: The Use of Historical Data for Determining “Go/No Go” Decision for Definitive Phase III Testing
Authors: Vickers Andrew J. , Ballen Vennus , Scher Howard I.
Published: February 2007

Purpose: Phase II trials aim to determine whether a cancer treatment is sufficiently promising to justify phase III study. Whether an agent is declared promising in a phase II trial depends on prespecified “null” and “alternative” rates of an outcome of interest such as tumor response. In some cases, the null must be determined with reference to historical data. We sought to determine the proportion of phase II trials that require historical data to establish the null and to determine how these historical estimates were derived.

Experimental Design: We conducted a systematic review of phase II trials published in the Journal of Clinical Oncology or Cancer in the 3 years to June 2005. Data were extracted following a prespecified protocol.

Results: We retrieved 251 papers, of which 117 were found to be ineligible; 70 of 134 included trials (52%) were defined as requiring historical data for design. Nearly half (32, 46%) of these papers did not cite the source of the historical data used, and just 9 (13%) clearly gave a single historical estimate as the rationale for the null. Trials that failed to cite prior data appropriately were significantly more likely to declare an agent to be active (82% versus 33%; P = 0.005). No study incorporated statistical methods to account for either sampling error or possible differences in case mix between the phase II sample and the historical cohort.

Conclusions: Many phase II trials require historical data to determine null response rates. Simple guidelines may improve design and reporting of such trials.
Site tenacity in European pond turtle (Emys orbicularis) hatchlings in Northwestern Spain
Authors: Ayres César , Cordero Adolfo
Published: February 2007

High fidelity of European pond turtle (Emys orbicularis) hatchlings to optimal patches of habitat was observed for the first time in the most western population of Spain. To achieve this information we used a permanent marker to identify hatchlings, which allow us to follow the daily activity of the hatchlings without disturbing their behaviour. Hatchlings were observed associated with dense masses of Potamogeton sp., in areas with shallow water, up to 1.5 m, close to the shoreline. Our hypothesis is that hatchlings used these areas because there are no temporary ponds or streams that could be an optimal habitat. These preliminary data could be useful for planning management of protected wetlands.
Pets and invasion risks: is the Slider turtle strictly carnivorous?
Authors: Prévot-Julliard Anne-Caroline , Gousset Emeline , Archinard Chloé , Cadi Antoine , Girondot Marc
Published: February 2007

According to the International Union for Conservation of Nature (IUCN),
invasive species are one of the most important causes of biodiversity
decline at a global scale. The impact of introduced species on local
ecosystems is thus important to evaluate. Pet voluntary introductions are
made by private people and usually concern only one or two individuals per
occasion. However, the number of release occasions is as numerous as the
number of pet owners that don't want to keep their pet anymore and then
decide to "release" it. Hatchling red-eared slider turtles (Trachemys
scripta elegans) have been massively exported from the United States to
European (until 1997) and Asian countries to be sold as pets. Many owners,
ignoring the potential consequences of their act, have released their grown
up turtle in natural freshwater ecosystems. As a consequence, feral adult
turtles have been detected all over France. In this paper, we provide
information that contradicts public opinion that introduced slider turtle is
strictly carnivorous. By analysing the diet of feral adult turtles, we found
that adult slider turtles are omnivorous, as in their natural areas.
Comparing Filippi and Luiselli's (2000) method with a cartographic approach to assess the conservation status of secretive species: the case of the Iberian snake-fauna
Authors: Santos Xavier , Brito José C. , Pleguezuelos Juan M. , Llorente Gustavo A.
Published: February 2007

The conservation status of the snake fauna of a given region or territory is
often hard to estimate due the secretive habits of these animals, as well as
of the lack of long-term demographic studies and generally low population
densities. We examined the conservation status of the snakes from the
Iberian Peninsula by applying two complementary methods. The first method,
created by Filippi and Luiselli for a study of the Italian snakes
conservation status, takes into account the ecological and non-ecological
attributes which make species vulnerable to extinction. The second is a
cartographic analysis which consists of calculating two indexes derived from
the comparison of old and recent citations in UTM 10 × 10 km squares of
Iberian snakes by means of extensive database sets. For each species, we
calculated the percentage of recent citations, and the percentage of squares
with both old and recent citations. Species with low proportion of recent
citations and new squares appeared to be in decline. We found considerable
coincidence between the two methods in the identification of the most
threatened snake species: Vipera latastei, Coronella girondica, and Natrix
natrix. We suspect that the ecological specialisation and the low
reproductive output make C. girondica and V. latastei prone to extinction
when faced with environmental changes (i.e. habitat loss). For N. natrix, we
argue that this semi-aquatic snake experiences suboptimal environmental
conditions in Mediterranean habitats. A combination of both methods proved
adequate to detect vulnerability to extinction of snake species, hence
revealing an effective tool for establishing conservation strategies in
snakes and other secretive faunas.
The temperature-sensitive period (TSP) during incubation of broad-snouted caiman (Caiman latirostris) eggs
Authors: Piña Carlos , Siroski Pablo , Larriera Alejandro , Lance Valentine , Verdade Luciano M.
Published: February 2007

All crocodiles studied to date exhibit temperature-dependent sex
determination. During the many weeks from egg laying to hatch there is a
period of 10 to 15 d in the middle third of incubation (in the American
alligator) during which the sex of the embryo is irreversibly fixed,
referred to as the temperature-sensitive period or TSP. In this work we
investigated the TSP in Caiman latirostris eggs incubated at female-inducing
and male-inducing temperatures (29° C and 33° C respectively) by switching
eggs from 29° C to 33° C and vice versa at timed interval throughout
incubation. Compared to Alligator mississippiensis the duration of TSP was
longer, and the onset of TSP was at an earlier stage of incubation.
Habitat selection in the Pampa de Achala toad, Bufo achalensis
Authors: Jofré Gabriela , Reading Christopher , di Tada Ismael
Published: February 2007

Habitat selection in adult and juvenile Bufo achalensis was studied at La Ciénaga Stream, Pampa de Achala, Central Argentina from December 1998 to October 2001. Habitat preference was evaluated by comparing the observed use of each habitat type with its availability. Juveniles were surveyed on 32 occasions between January 1999 and March 2001 using 13 permanent transects. The effect of cattle on larval survivorship was also evaluated. Most adult and juvenile B. achalensis occurred within 300 m of each side of the breeding site stream. No correlation was found between body size and distances moved. Juveniles and adults selected granite outcrops after the breeding season and avoided the heavily grazed areas. Adults also selected the stream and used tall tussock grassland in proportion to its availability. Juveniles used loose, flat, relatively small stones as shelters whilst adults used larger rocks. The presence of cattle at the breeding sites directly reduced larval survivorship by trampling, and indirectly through sediment deposition at the breeding sites resulting from increased stream bank erosion. The habitat preferences of B. achalensis suggest that long term cattle grazing also affects them adversely through deterioration of their transition habitat from tall tussock grassland to short sward. Future conservation management plans for B. achalensis must include the protection of the breeding sites and the surrounding terrestrial area if they are to be effective.
Genetic variation within African spiny-tailed lizards (Agamidae: Uromastyx) estimated using mitochondrial DNA sequences
Authors: Harris D. James , Vaconcelos Raquel , Brito José C.
Published: February 2007

African spiny-tailed lizards (Uromastyx) are large, herbivorous lizards
extensively traded locally for food and internationally as pets. Several
species have recently been described, although some remain controversial. To
determine relationships within North African forms, twenty individuals were
analysed for over 1000 bases of mitochondrial DNA sequences. Phylogenetic
analyses indicate four deeply divergent lineages that correspond to sampling
areas, but not to current species designations. These results indicate that
present taxonomy does not reflect the evolutionary history of these
species.
Coaching Process Outcomes of a Family Visit Nutrition and Physical Activity Intervention
Authors: Heimendinger Jerianne , Uyeki Terry , Andhara Aurielle , Marshall Julie A. , Scarbro Sharon , Belansky Elaine , Crane Lori
Published: February 2007

The purpose of this article is to report the process outcomes of a coaching methodology used in a study designed to increase fruit and vegetable consumption and physical activity in families. Eighty-eight families with second graders were recruited from a rural, biethnic community in Colorado and randomized to intervention and delayed intervention conditions. This article reports on the 27 families in the delayed intervention group. Families received up to 10 home visits over 10 months from a family advisor and completed activities to improve their dietary and physical activity behaviors. Coaching conversations took place during each home visit. Coaching process outcomes were evaluated by analysis of visit documentation, participant survey, and qualitative interviews. Results indicated that coaching, in conjunction with family activities, engaged families in the process of change and facilitated movement toward the achievement of their weekly nutrition or physical activity goals. Coaching methodology may be particularly useful for participatory research.
Pathways to Health: A Cluster Randomized Trial of Nicotine Gum and Motivational Interviewing for Smoking Cessation in Low-Income Housing
Authors: Okuyemi Kolawole S. , James Aimee S. , Mayo Matthew S. , Nollen Nicole , Catley Delwyn , Choi Won S. , Ahluwalia Jasjit S.
Published: February 2007

Despite high smoking rates among those living in poverty, few cessation studies are conducted in these populations. This cluster-randomized trial tested nicotine gum plus motivational interviewing (MI) for smoking cessation in 20 low-income housing developments (HDs). Intervention participants (10 HDs, n = 66) received educational materials, 8 weeks of 4 mg nicotine gum, and 5 MI sessions on quitting smoking. Comparison participants (10 HDs, n = 107) received 5 MI sessions and educational materials addressing fruit and vegetable consumption. Participants had a mean age of 46.3 years and were predominantly female (70%) and African American (83%). Biochemically-verified 7-day abstinence rates at 8 weeks were 6.1% and 5.6% in the intervention and comparison arms, respectively ( p = ns); and at 26 weeks were 7.6% and 9.3%, respectively ( p = ns). Results suggest that nicotine gum plus MI were not effective for smoking cessation in low-income housing. Programs are needed to enhance the effectiveness of pharmacotherapy and counseling in underserved populations.
Specialised in-patient treatment for severe, chronic, resistant obsessive–compulsive disorder
Authors: Drummond Lynne M. , Pillay Anusha , Kolb Peter , Rani Shashi
Published: February 2007

Aims and Method

A naturalistic study was conducted to examine the outcome on self-report and observer-rated measures in patients with severe, chronic, resistant obsessive–compulsive disorder (OCD) admitted to a specialised in-patient unit.

Results

Twenty-six patients were admitted over the study period. The mean age of all patients was 37 years (s.d.=13.8, range 18–61 years) and they had a mean duration of OCD of 18.4 years (s.d.=10.9, range 4–40 years). Instruments measuring severity demonstrated a 37–67% reduction in obsessive–compulsive symptoms and a 64% reduction in depressive symptoms after an average of almost 15 weeks in hospital.

Clinical Implications

This study demonstrates that specialised in-patient care can benefit a small group of severely ill patients with OCD who fail to respond to treatment in primary and secondary care.
MRCPsych examinations: cumulative results 1997–2002
Authors: Oyebode Femi , Furlong Elizabeth
Published: February 2007

Aims and Method

The aim of this study was to investigate the pattern of performance of candidates in the MRCPsych examinations in the period 1997–2002 inclusive. During this period 6306 candidates sat the MRCPsych part I and 4536 sat the MRCPsych part II.

Results

The overall pass rates for MRCPsych part I was 44.7% and 48.9% for MRCPsych part II. The majority of those who passed either part of the examinations did so on their first attempt; females performed better than males and graduates of UK and Republic of Ireland medical schools performed better than foreign graduates in all component parts of the examinations.

Clinical Implications

The pattern of results suggests that clinical tutors and course organisers need to pay special care to the training needs of trainees who are foreign medical graduates.
A Consideration of the Relationship between Subjective Unpleasantness and Body Surface Vibrations Induced by High-Level, Complex Low-Frequency Noise
Authors: Takahashi Yukio
Published: February 2007

To investigate the relationship between subjective unpleasantness and body surface vibrations induced by high-level, complex low-frequency noise, we carried out two expetiments. Body surface vibrations were measured at the right and left anterior chest and the right and left anterior abdomen of male subjects. Subjective unpleasantness was rated on a scale of 1 to 5, and correlated with the vibration acceleration levels (VALs) of the vibrations measured on the body surface. As a result, it was found that the ratings of unpleasantness did, on the whole, significantly correlate with the VALs. In addition, we estimated the frequency-weightings for the VAL to optimize the correlation with the rating of unpleasantness. Based on a reasonable hypothesis, the frequency-weightings estimated in the present study were considered to be consistent with those estimated in our previous study using low-frequency pure tones. The present results support the idea that not only the loudness of a noise, but also the vibrations induced by that noise, contribute to the subjective unpleasantness experienced by persons exposed to high-level low-frequency noise. The effect of vibration should be taken into consideration in evaluating high-level low-frequency noise.
Development of an Active Vibration Isolation System Using a Z-Bracket Based on PZT
Authors: Qingsong Cao , Weijia Ll
Published: February 2007

This present paper makes a tentative study on an active isolation system which utilizes a bracket bonded with PZTs. Two big PZTs is used as actuators, and two small ones are used as sensors to detect the internal response of the Z-bracket. Accelerometers are used to detect the original vibration original and the isolated vibration level. The adaptive feedforward algorithm for active vibration isolation is improved in this study. The experiment demonstrates the efficiency of the isolation performance of the Z-bracket bonded with PZTs using adaptive feedforward control.
Between Empowerment and Power: The Rise of the Self-Supporting Church in Western Flores, Eastern Indonesia
Authors: Erb Maribeth
Published: February 2007

This article explores how ideas about empowerment often end up being manipulated by those in power, its implications, and what effect this has had on the trajectory of the Catholic Church in the western part of Flores during this period of revival, empowerment, and "indigenization". What many have referred to as a "decentralization of money politics" into the provincial regions during the regional autonomy era seems to have reinforced an increasing emphasis on money in power configurations; this has occurred not only in local political dealings, but also in the church hierarchy. Against the wider historical background of the Catholic Church in Western Flores, particularly the rise of the "self-supporting Church" in the Manggaraian Diocese, this article examines developments of indigenizing and empowering the local Catholic community. The suggestion is that the conflicts in the Manggaraian Church reflect strains that have existed historically in the structure of the Catholic Church and represent tension within the Church between struggles for power over the community and efforts to empower the community.
Muhammadiyah, Local Politics and Local Identity in Kotagede
Authors: Sulistiyanto Priyambudi
Published: February 2007

This article is a preliminary observation of local politics and local identity in Kotagede, Central Java, Indonesia, during the post-Soeharto period. It examines the roles of Muhammadiyah and local actors in maintaining local identity in this town. I highlight the importance of Islamic and Javanese traditions in shaping the local history and the dynamics of local politics in Kotagede. I also argue that there is a place for local actors and social networks in the pursuit of preserving local identity in this town. Some observations are made about the impact of the Yogyakarta earthquake and future research directions.
Piezoresistive Behavior Study on Finger‐Sensing Silicone Rubber/Graphite Nanosheet Nanocomposites
Authors: Chen L. , Chen G. H. , Lu L.
Published: January 2007

A novel finger‐sensing nanocomposite with remarkable and reversible piezoresistivity is successfully fabricated by dispersing homogeneously conductive graphite nanosheets (GNs) in a silicone rubber (SR) matrix. Because of the high aspect ratio of the graphite nanosheets, the nanocomposite displays a very low percolation threshold. The SR/GN nanocomposite with a volume fraction of conductive nanosheets closest to that for the percolation threshold presents a sharp positive‐pressure coefficient effect of the resistivity under very low pressure, namely, in the finger‐pressure range (0.3–0.7 MPa), whereby the abrupt transition could be attributed to compressive‐stress‐induced deformation of the conducting network. The super‐sensitive piezoresistive behavior of the nanocomposite is accounted for by an extension of the tunneling conduction theory which provides a good approximation to the piezoresistive effect.
Cover Picture: Synthesis of Polyaniline Nanotubes with a Reactive Template of Manganese Oxide (Adv. Mater. 3/2007)
Authors: Pan L. J. , Pu L. , Shi Y. , Song S. Y. , Xu Z. , Zhang R. , Zheng Y. D.
Published: January 2007

Polyaniline nanotubes can be synthesized through a chemical template method. The shape and major parameters of the tubes are precisely controlled by the reactive templates of MnO2 nanowires, which also act as the oxidative initiator for polymerization. The cover image shows an example where the rectangular tubes are cloned from the cryptomelane‐phase MnO2, as reported on p. 461 by Shi and co‐workers.
High surface area titania photocatalytic microfluidic reactors
Authors: Lindstrom Henrik , Wootton Robert , Iles Alexander
Published: February 2007

In this work a simple method is described for depositing a robust yet highly porous film of anatase titania nanoparticles with a very high surface area onto the inside walls of microfluidic devices. A very high loading of 66 g of titania per liter of reactant solution was achieved. The effectiveness is demonstrated of this deposition method by producing functionalized microfluidic reactor devices and using them to photocatalytically degrade air‐saturated methylene blue solutions. Experiments were performed with and without the addition of gaseous oxygen to the microreactors. The addition of oxygen dramatically enhanced the degradation rate. This highlights the necessity for supplying additional oxygen to microsystems during photocatalysis since dissolved oxygen can be rapidly depleted within the small confined space inside microreactors. With additional gaseous oxygen, the conversion rate for the photodegradation reaction of 0.1mM methylene blue at a flow rate of 12 μl min−1 was 10.6 % s−1. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Modeling l‐dopa purification by chiral ligand‐exchange chromatography
Authors: Sanaie Nooshafarin , Haynes Charles A.
Published: February 2007

A model describing elution‐band profiles that combines multiple chemical equilibria theory with the nonideal equilibrium–dispersion equation for solute transport is used to predict and characterize the separation of l,d‐dopa by chiral ligand‐exchange chromatography (CLEC). Formation constants and stoichiometries for all equilibrium complexes formed in the interstitial volume and pore liquid are taken from standard thermodynamic databases and independent potentiometric titration experiments. Formation constants for complexes formed with the stationary phase ligand (N‐octyl‐3‐octylthio‐d‐valine) are determined from potentiometric titration data for a water‐soluble analogue of the ligand. This set of pure thermodynamic parameters is used to calculate the spatially discretized composition of each column volume element as a function of time. The model includes a temperature‐dependent pure‐component parameter, determined by regression to a single elution band for the pure component, that corrects for subtle effects associated with immobilizing the N‐octyl‐3‐octylthio‐d‐valine ligand onto the stationary phase. The model is shown to accurately predict elution chromatograms and separation performance as a function of key column operating variables. The model is then used to better understand the connection between chemical equilibria within the system and changes in band profiles and band separation resulting from changes in column operating conditions. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Titelbild: Die aufregende Chemie des Tetraazidomethans (Angew. Chem. 7/2007)
Authors: Banert Klaus , Joo Young‐Hyuk , Rüffer Tobias , Walfort Bernhard , Lang Heinrich
Published: January 2007

Nicht nur als Explosivstoff, sondern auch dank seiner überraschenden Reaktionen ist Tetraazidomethan eine aufregende Substanz. Es kann in einer Stufe aus Trichloracetonitril hergestellt, durch präparative Gaschromatographie isoliert und mithilfe des 15N‐NMR‐Spektrums charakterisiert werden. Während mit Cyclooctin ein einfaches Abfangprodukt gebildet wird, geht Tetraazidomethan mit Norbornen eine komplexere Umwandlung ein. Weitere Reaktionen beschreiben K. Banert et al. in ihrer Zuschrift auf S. 1187 ff.
Innentitelbild: NMR Study of Water Molecules Confined in Extended Nanospaces (Angew. Chem. 7/2007)
Authors: Tsukahara Takehiko , Hibara Akihide , Ikeda Yasuhisa , Kitamori Takehiko
Published: January 2007

In begrenzten Räumen zeigt Wasser einzigartige Eigenschaften, die im Volumenmaßstab unbekannt sind. In der Zuschrift auf S. 1199ff. beschreiben T. Kitamori et al. die lokalen strukturellen und dynamischen Eigenschaften von Wasser in Räumen von einigen zehn bis mehreren hundert Nanometern auf einem Glas‐Chip. Mithilfe von NMR‐Daten wird ein Modell für den Grenzbereich aus locker verbundenen Wassermolekülen zwischen Oberfläche und Volumenphase (siehe Bild) vorgeschlagen. Die Ergebnisse sind wichtig für das Implementieren von Mikro‐/Nanofluidikbauteilen auf einem Chip.
Marine research, resources and conservation in the Azores
Authors: Santos Ricardo Serrão , Hawkins Stephen , Monteiro Luis Rocha , Alves Mário , Isidro Eduardo José
Published: February 2007

A history of marine research on the Azores is outlined. Until two decades ago most oceanic and littoral marine studies had been carried out by foreign scientists. Studies by Azorean scientists started to increase in the early 1980s when the University of the Azores was created.

Ocean circulation in this part of the Atlantic is described as a background for biogeography and diversity. The picture emerges that Azores is a ‚meeting point’︁ for shallow water marine fauna and flora of different origins.

The species composition of one of the best studied groups of organisms, the fish, is compared between locations in the northeastern Atlantic. The work on fish is also compared with other well studied groups (algae and hydroids) to highlight the interest of the Azores as a natural biogeographical experiment.

Studies of marine resources began less than two decades ago. The development of demersal fisheries is described focusing on the switch from small‐scale artisanal fishing to more commercial fisheries.

Conservation of species and legislation in force for molluscs, crustaceans, fishes, marine turtles, seabirds and marine mammals are summarized.

Protected marine areas already designated are defined, as well as new areas recommended.

The paper concludes with a discussion of current threats and future management strategies.
Energy Landscape of Aptamer/Protein Complexes Studied by Single‐Molecule Force Spectroscopy
Authors: Yu Junping , Jiang Yaxin , Ma Xinyong , Lin Yi , Fang Xiaohong
Published: January 2007

Aptamers are single‐stranded nucleic acid molecules selected in vitro to bind to a variety of target molecules. Aptamers bound to proteins are emerging as a new class of molecules that rival commonly used antibodies in both therapeutic and diagnostic applications. With the increasing application of aptamers as molecular probes for protein recognition, it is important to understand the molecular mechanism of aptamer–protein interaction. Recently, we developed a method of using atomic force microscopy (AFM) to study the single‐molecule rupture force of aptamer/protein complexes. In this work, we investigate further the unbinding dynamics of aptamer/protein complexes and their dissociation‐energy landscape by AFM. The dependence of single‐molecule force on the AFM loading rate was plotted for three aptamer/protein complexes and their dissociation rate constants, and other parameters characterizing their dissociation pathways were obtained. Furthermore, the single‐molecule force spectra of three aptamer/protein complexes were compared to those of the corresponding antibody/protein complexes in the same loading‐rate range. The results revealed two activation barriers and one intermediate state in the unbinding process of aptamer/protein complexes, which is different from the energy landscape of antibody/protein complexes. The results provide new information for the study of aptamer–protein interaction at the molecular level.
Boomerang‐Type Substitution Reaction: Reactivity of Fullerene Epoxides and a Halofullerenol
Authors: Jia Zhenshan , Zhang Xiang , Zhang Gaihong , Huang Shaohua , Fang Hao , Hu Xiangqing , Li Yuliang , Gan Liangbing , Zhang Shiwei , Zhu Daoben
Published: January 2007

The Cs‐symmetric fullerene chlorohydrin C60(Cl)(OH)(OOtBu)4 reacts with 4‐dimethylaminopyridine (DMAP) and 1,4‐diazabicyclo[2.2.2]octane (DABCO) to yield two isomers with the formula C60(O)(OOtBu)4 in good yields. These isomers differ with respect to the location of the epoxy functionality. The one from DMAP is Cs symmetric, whereas that from DABCO is C1 symmetric with the epoxy group on the central pentagon. Two different mechanisms are proposed to explain the chemoselectivity of these reactions. The reaction with DMAP involves single‐electron transfer as the key step; DMAP acts as the electron donor. A combination of an oxygen‐atom shift and SN2′′ processes (boomerang substitution) are responsible for the formation of isomer with DACBO. Various related reactions support the proposed mechanisms. The structures of new fullerene derivatives were determined by spectroscopy, single‐crystal X‐ray analysis, and chemical correlation experiments.
Photoluminescent and Liquid‐Crystalline Properties of Donor–Acceptor‐Type 2,5‐Diarylthiazoles
Authors: Shikuma Junichi , Mori Atsunori , Masui Kentaro , Matsuura Ryuichi , Sekiguchi Akitoshi , Ikegami Haruka , Kawamoto Masuki , Ikeda Tomiki
Published: January 2007

The synthesis of donor–acceptor‐type 2,5‐diarylthiazoles that bear electron‐donating N,N‐dialkylamine and electron‐withdrawing cyano groups at the 2‐ and 5‐position, respectively, were carried out with transition‐metal‐catalyzed CH arylation reactions developed by us. The compounds were synthesized by the CH arylation of unsubstituted thiazole at the 2‐position with a palladium/copper catalyst in the presence of tetrabutylammonium fluoride (TBAF) as an activator. Further CH arylation of the 2‐arylated thiazole at the 5‐position was carried out by the palladium‐catalyzed reaction in the presence of silver(I) fluoride to afford the donor–acceptor‐type 2,5‐diarylthiazoles with N,N‐dialkylamine groups of different chain lengths. The UV/Vis absorption, photoluminescence, and electrochemical behavior were similar regardless of chain length, whereas liquid‐crystalline behavior and thermal characteristics were found to be dependent on the alkyl‐chain length. The compounds with N,N‐diethylamine or N‐butyl‐N‐methyl groups showed a stable liquid‐crystalline phase over a wide temperature range as well as higher stability to thermal decomposition.
Easily Accessible Benzamide‐Derived P,O Ligands (Bphos) for Palladium‐Catalyzed Carbon–Nitrogen Bond‐Forming Reactions
Authors: Chen Guoshu , Lam Wai Har , Fok Wai Shan , Lee Hang Wai , Kwong Fuk Yee
Published: January 2007

Easily accessible benzamide‐derived hemilabile phosphine ligands were efficiently prepared through ortho‐directed lithiation of the corresponding N,N‐diethylbenzamide followed by quenching with chlorodialkylphosphines. These structurally simple hemilabile ligands were found to be highly effective in palladium‐catalyzed amination of aryl and heteroaryl chlorides. Various sterically congested and functionalized aryl halide substrates were compatible in these reaction conditions. By using optimized reaction conditions, remarkable catalyst productivity (total turnover number up to 8400) was obtained.
Synthesis and Application of a Bidentate Ligand Based on Decafluoro‐3‐phenyl‐3‐pentanol: Steric Effect of Pentafluoroethyl Groups on the Stereomutation of O‐Equatorial C‐Apical Spirophosphoranes
Authors: Jiang Xin‐Dong , Kakuda Ken‐ichiro , Matsukawa Shiro , Yamamichi Hideaki , Kojima Satoshi , Yamamoto Yohsuke
Published: January 2007

1,1,1,2,2,4,4,5,5,5‐Decafluoro‐3‐phenyl‐3‐pentanol was prepared by a Cannizzaro‐type disproportionation reaction, and the dimetallated compound was used as a bidentate ligand, which is bulkier than the Martin ligand (1,1,1,3,3,3‐hexafluoro‐2‐phenyl‐2‐propanol). A PH spirophosphorane was synthesized by utilizing the new bidentate ligand, and the structure of the product was essentially the same as that of the PH phosphorane with Martin ligands. Phosphoranes that exhibit reversed apicophilicity (O‐equatorial) were also synthesized and could be converted into the corresponding stable stereoisomers (O‐apical). The crystal structures of O‐equatorial phosphoranes and the O‐apical isomers were slightly affected by the steric repulsion of pentafluoroethyl groups. Kinetic measurements revealed that the stereomutation of O‐equatorial methylphosphorane to the O‐apical isomer was slowed. The activation enthalpy for the stereomutation of the former to the latter was higher than that of the phosphorane with Martin ligands by 5.1 kcal mol−1.
Cover Picture: Shape‐ and Functionality‐Controlled Organization of TiO2–Porphyrin–C60 Assemblies for Improved Performance of Photochemical Solar Cells (Chem. Asian J. 2/2007)
Authors: Hasobe Taku , Fukuzumi Shunichi , Hattori Shigeki , Kamat Prashant V.
Published: January 2007

The search for green energy production is well underway with the emergence of dye‐sensitized photoelectrochemical cells as a promising alternative for the development of next‐generation solar cells. Supramolecular assemblies of porphyrin and C60 are potential candidates as components of photoelectrochemical cells, as they undergo efficient photoinduced electron‐transfer processes. The hierarchical organization of these assemblies is an important aspect for maximizing the efficiency of light‐energy conversion. In their Full Paper on page 265 ff., S. Fukuzumi, P. V. Kamat, and co‐workers employed TiO2 nanotubes and nanoparticles to produce porphyrin–C60 supramolecular assemblies for photochemical solar cells. The differences in the efficiency of light‐energy conversion of these solar cells are also explained.
Veränderung der Steifigkeit und des Dehnungsverhaltens von Normalbeton bei zyklischer Druckschwellbeanspruchung mit Ruhephasen
Authors: Breitenbücher Rolf , Ibuk Hursit , Osterminski Kai
Published: January 2007

Betonbauwerke werden häufig neben rein statischen Lasten auch durch zyklische Lasten beansprucht. Durch Letztere kann bereits während zahlreicher Lastwechsel eine Degradation des Betongefüges eintreten, die zu größeren Dehnungen und zu reduzierten Steifigkeiten führen. Unklar ist, wie sich Ruhephasen innerhalb dieser zyklischen Beanspruchung auf das Dehnungsverhalten und die Steifigkeitsentwicklung auswirken. Im Rahmen des Sonderforschungsbereiches 398 werden lebensdauerorientierte Entwurfskonzepte unter Schädigungs‐ und Deteriorationsaspekten entwickelt. Hierin wird im Teilprojekt A13 die Degradation der Materialeigenschaften des Betons infolge von zyklischer Druckschwellbelastung untersucht. Im folgenden Beitrag wird vom Einfluss von einmalig auftretenden Ruhephasen innerhalb sinusförmiger Druckschwellbelastungen auf das Dehnungs‐ und Steifigkeitsverhalten von Normalbeton berichtet. Dazu wurden Betonproben zwei unterschiedlichen Belastungsregimen (Lastniveau, Frequenz) ausgesetzt. Innerhalb dieser wurden verschieden lang andauernde Ruhephasen eingebaut. Während der Belastungs‐ und Ruhephasen wurden die Probekörperdehnungen und indirekt der E‐Modul (über Ultraschalllaufzeitmessungen) bestimmt. Die Versuchsergebnisse besagten, dass bei den betrachteten Belastungshistorien Ruhephasen keinen signifikanten Einfluss auf das Dehnungsverhalten der Betonprobekörper besaßen. Geringfügige Erholungen infolge des verzögert‐elastischen Verhaltens des Betons in der Ruhephase waren nach erneuter Aufnahme der Beanspruchung rasch wieder aufgebraucht. Gleiches gilt für die Auswirkungen auf die Steifigkeit des Betons.
Bemessungsvorschlag für die verstärkte Querbewehrung bei mehrgeschossigen Ortbetonstützen ohne Übergreifungsstoß der Längsbewehrung. “Stumpfstoß von Ortbetonstützen”
Authors: Minnert Jens , Günther Gerd
Published: January 2007

An der Fachhochschule Gießen‐Friedberg wurden zahlreiche Untersuchungen zum Tragverhalten von stumpf gestoßenen Ortbetonstützen durchgeführt. Anhand gezielter Versuche wurde das Verhalten der Stützen zunächst im Labor untersucht. Anschließend erfolgten die Nachrechnung der Versuche und eine weiterführende Parameterstudie mit einem nichtlinearen FEMProgramm. Darauf aufbauend wurde ein Bemessungsvorschlag entwickelt.
Näherungsweise Spannungsberechnung vorgespannter Betonbauteile
Authors: Mertzsch Olaf
Published: January 2007

Mit Einführung der DIN 1045‐1 (07.2001) erfolgt die Bemessung von Stahlbeton‐ und Spannbetontragwerken nach einer einheitlichen Berechnungsvorschrift. Hiermit besteht die Möglichkeit einer besseren Auslastung der Konstruktion. Dies hat zur Folge, dass den Nachweisen der Gebrauchstauglichkeit eine größere Bedeutung zukommt. Ziel der nachfolgenden Betrachtungen ist es, wirklichkeitsnahe Berechnungsansätze zur Vorhersage der Beton‐ und Stahlspannungen abzuleiten. Diese Berechnungsansätze ermöglichen eine einfache Abschätzung der Spannungen und sind auch für Handrechnungen geeignet.
Rissbreitenberechnung bei “Kombibewehrung”
Authors: Henke Volker , Empelmann Martin
Published: January 2007

Stahlfaserbeton findet in den letzten Jahren eine immer weiter verbreitete Anwendung im konstruktiven Ingenieurbau. Dies gilt für Bauteile aus reinem Stahlfaserbeton, aber auch für die Kombination mit normaler Betonstahlbewehrung (Kombibewehrung), wo dann auch immer wieder die Frage der Rissbreitenberechnung zu klären ist. Besonders zu beachten ist dabei das Zusammenwirken von Bewehrungsstahl und Stahlfasern. Einige Bemessungsansätze für reinen Stahlfaserbeton und Bauteile mit Kombibewehrung sind in der Literatur vorhanden, wobei die Bemessungsansätze für Kombibewehrung die Grundlagen der DIN 1045‐1 verwenden. In diesem Aufsatz soll die Anwendbarkeit dieser Ansätze für eine Kombibewehrung, auf der Basis vorhandener Versuchsergebnisse, überprüft und auf einige Besonderheiten beim Ansatz der Nachrisszugfestigkeit des Stahlfaserbetons hingewiesen werden.
Anwendungserfahrungen mit der neuen DIN 1055 Teil 6 bei der Sanierung zweier Rohmehlsilos
Authors: Kaldenhoff Martin , Schütte Jens , Hauser Arthur
Published: January 2007

Dem Sanierungskonzept war aufgrund von vielen Randbedingungen ein enges Korsett vorgegeben. Unter anderem war die neue deutsche Silonorm DIN 1055‐6: 2005‐03 einzuhalten. Die Anwendung der neuen Silonorm ist anspruchsvoll und zeitintensiv. Die neue Konstruktion ist in allen Belangen durch die neue Norm beeinflusst worden. Augenfällig ist die externe Vorspannung, welche als Neuheit gänzlich während des Gleitens von einem zweiten Nachläufer aus aufgebracht wurde.

Ein Siloprojekt kann und soll nicht auf die rechnerische Anwendung einer Silonorm reduziert werden. Drei Ziele führen zum ganzheitlichen Erfolg:

– Schüttguteigenschaften kennen und abdecken

– Rechnerische Auslegung mittels Silonorm aber nicht ohne Erfahrungswerte

– Professionelle Bauausführung und Bauüberwachung

Die neue Silonorm DIN 1055‐6 hilft beim Erreichen dieser Ziele auf weiten Strecken. Ihre Anwendung erfordert entsprechende Erfahrung im Silobau und gesunden Ingenieurverstand.
Teilüberdeckelung einer innerstädtischen Bundesstraße mit Spannbetonfertigteilen
Authors: Sobek Werner , Straub Wolfgang , Ploch Jan
Published: January 2007

Die Stuttgarter Innenstadt wird von einer breiten Bundesstraße durchschnitten, die unter einigen großen Kreuzungen in Unterführungen verläuft. Durch die teilweise Überdeckelung der Unterführungseinfahrten können zusätzliche Grünflächen und ebenerdige Fußgängerüberwege geschaffen werden. Die erste Teilüberdeckelung konnte durch integrierte Planung und den Einsatz von Spannbetonfertigteilen nach einer extrem kurzen Planungs‐ und Bauzeit eingeweiht werden.
Diskussionsforum: Nanobewehrung von Schaumbeton
Authors: Yakovlev Grigory , Kerienė Jadvyga , Plechanova Tatyana , Krutikov Vyacheslav
Published: January 2007

In der hier vorgestellten Studie wurden Nanoröhren aus Karbon, die aus aromatischen Kohlenwasserstoffen synthetisiert werden, untersucht. Ebenso sollten die Produktionsmöglichkeiten und grundsätzlichen technischen Eigenschaften eines Betons untersucht werden, der mit Nanoröhren aus Karbon verstärkt ist und auf Portlandzement basiert.

Für die Herstellung der Nanoröhren aus Karbon wurde die Methode der Stimulation der Dehydropolykondensation und Verkokung der aromatischen Kohlenwasserstoffe in chemisch aktiver Umgebung gewählt (Schmelzen von Aluminium‐, Kupfer‐, Nickel‐ und Eisensalzen). Die Untersuchung der synthetisierten Nanoröhren aus Karbon mittels photoelektrischer Röntgenspektroskopie ergab einen Karbonanteil von 80–90%. Unter dem Elektronenmikroskop konnte festgestellt werden, dass Nanoröhren aus Karbon eine zylindrische Form mit Durchmessern bis zu 100 nm und Längen bis 20 μm aufweisen. Sie sind zu faserförmigen Agglomeraten mit Durchmessern von bis zu 30 μm und Längen bis zu 10 mm zusammengeballt.

Die Nanoröhren aus Karbon wurden als hochfeste verteilte Bewehrung zur Herstellung von nicht autoklaviertem Schaumbeton verwendet. Die Untersuchung dieses Schaumbetons ergab, dass durch den Einsatz von Nanoröhren aus Karbon (0, 05% der Masse) eine Abnahme derWärmeleitfähigkeit um 12–20% sowie eine Zunahme der Druckfestigkeit um bis zu 70% erreichet werden kann.
Recent progress in the field of glycopeptide synthesis
Authors: Hojo Hironobu , Nakahara Yoshiaki
Published: February 2007

Glycosylation is a common post‐translational modification of proteins. Although its significance in biological system is well recognized, approaches to analyze carbohydrate function are limited. This is because of difficulty in obtaining homogeneous glycoproteins from natural sources. Due to the progress of the carbohydrate and peptide chemistry, syntheses of various homogeneous glycopeptides and glycoproteins, which are suitable for biological studies, have been achieved by chemical means. In this review, we briefly summarize recent advances in the field of glycopeptide synthesis after 1999. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 308–324, 2007.

This article was originally published online as an accepted preprint. The ‘Published Online’ date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Seven-year follow-up of a randomized clinical trial comparing proton-pump inhibition with surgical therapy for reflux oesophagitis
Authors: Lundell L , Miettinen P , Myrvold H E , Hatlebakk J G , Wallin L , Malm A , Sutherland I , Walan A
Published: January 2007

Background

This randomized clinical trial compared long-term outcome after antireflux surgery with acid inhibition therapy in the treatment of chronic gastro-oesophageal reflux disease (GORD).

Methods

Patients with chronic GORD and oesophagitis verified at endoscopy were allocated to treatment with omeprazole (154 patients) or antireflux surgery (144). After 7 years of follow-up, 119 patients in the omeprazole arm and 99 who had antireflux surgery were available for evaluation. The primary outcome variable was the cumulative proportion of patients in whom treatment failed. Secondary objectives were evaluation of the treatment failure rate after dose adjustment of omeprazole, safety, and the frequency and severity of post-fundoplication complaints.

Results

The proportion of patients in whom treatment did not fail during the 7 years was significantly higher in the surgical than in the medical group (66·7 versus 46·7 per cent respectively; P = 0·002). A smaller difference remained after dose adjustment in the omeprazole group (P = 0·045). More patients in the surgical group complained of symptoms such as dysphagia, inability to belch or vomit, and rectal flatulence. These complaints were fairly stable throughout the study interval. The mean daily dose of omeprazole was 22·8, 24·1, 24·3 and 24·3 mg at 1, 3, 5 and 7 years respectively.

Conclusion

Chronic GORD can be treated effectively by either antireflux surgery or omeprazole therapy. After 7 years, surgery was more effective in controlling overall disease symptoms, but specific post-fundoplication complaints remained a problem. There appeared to be no dose escalation of omeprazole with time.
Randomized clinical trial comparing botulinum toxin injections with 0·2 per cent nitroglycerin ointment for chronic anal fissure
Authors: Brisinda G , Cadeddu F , Brandara F , Marniga G , Maria G
Published: January 2007

Background

In recent years treatment of chronic anal fissure has shifted from surgical to medical. This study compared the ability of two non-surgical treatments—botulinum toxin injections and nitroglycerin ointment—to induce healing in patients with idiopathic anal fissure.

Methods

One hundred adults were assigned randomly to receive treatment with either type A botulinum toxin (30 units Botox® or 90 units Dysport®) injected into the internal anal sphincter or 0·2 per cent nitroglycerin ointment applied three times daily for 8 weeks.

Results

After 2 months, the fissures were healed in 46 (92 per cent) of 50 patients in the botulinum toxin group and in 35 (70 per cent) of 50 in the nitroglycerin group (P = 0·009). Three patients in the botulinum toxin group and 17 in the nitroglycerin group reported adverse effects (P < 0·001). Those treated with botulinum toxin had mild incontinence to flatus that lasted 3 weeks after treatment but disappeared spontaneously, whereas nitroglycerin treatment was associated with transient, moderate-to-severe headaches. Nineteen patients who did not have a response to the assigned treatment crossed over to the other therapy.

Conclusion

Although treatment with either topical nitroglycerin or botulinum toxin is effective as an alternative to surgery for patients with chronic anal fissure, botulinum toxin is the more effective option.