bluuebunny/crossref_metadata_2025 huggingface dataset:
FOXP3+ Tregs and B7-H1+/PD-1+T lymphocytes co-infiltrate the tumor tissues of high-risk breast cancer patients: Implication for immunotherapy
Authors: Ghebeh Hazem , Barhoush Eman , Tulbah Asma , Elkum Naser , Al-Tweigeri Taher , Dermime Said
Published: February 2008

Background

Recent studies have demonstrated a direct involvement of B7-H1, PD-1 and FOXP3 molecules in the immune escape of cancer. B7-H1 is an inhibitory molecule that binds to PD-1 on T lymphocytes, while FOXP3 is a marker for regulatory T cells (Tregs). We have previously demonstrated the association of B7-H1-expressing T infiltrating lymphocytes (TIL) with high-risk breast cancer patients while other studies reported the involvement of FOXP3+ Tregsas a bad prognostic factor in breast tumors. Although the co-existence between the two types of cells has been demonstratedin vitroand animal models, their relative infiltration and correlation with the clinicopathological parameters of cancer patients have not been well studied. Therefore, we investigated TIL-expressing the B7-H1, PD-1, and FOXP3 molecules, in the microenvironment of human breast tumors and their possible association with the progression of the disease.

Methods

Using immunohistochemistry, tumor sections from 62 breast cancer patients were co-stained for B7-H1, PD-1 and FOXP3 molecules and their expression was statistically correlated with factors known to be involved in the progression of the disease.

Results

A co-existence of B7-H1+T lymphocytes and FOXP3+Tregswas evidenced by the highly significant correlation of these molecules (P< .0001) and their expression by different T lymphocyte subsets was clearly demonstrated. Interestingly, concomitant presence of FOXP3+Tregs, B7-H1+and PD-1+TIL synergistically correlated with high histological grade (III) (P< .001), estrogen receptor negative status (P= .017), and the presence of severe lymphocytic infiltration (P= .022).

Conclusion

Accumulation of TIL-expressing such inhibitory molecules may deteriorate the immunity of high-risk breast cancer patients and this should encourage vigorous combinatorial immunotherapeutic approaches targeting Tregsand B7-H1/PD-1 molecules.
The association of urinary cadmium with sex steroid hormone concentrations in a general population sample of US adult men
Authors: Menke Andy , Guallar Eliseo , Shiels Meredith S , Rohrmann Sabine , Basaria Shehzad , Rifai Nader , Nelson William G , Platz Elizabeth A
Published: February 2008

Background

Studies investigating the association of cadmium and sex steroid hormones in men have been inconsistent, but previous studies were relatively small.

Methods

In a nationally representative sample of 1,262 men participating in the morning examination session of phase I (1998–1991) of the third National Health and Nutrition Examination Survey, creatinine corrected urinary cadmium and serum concentrations of sex steroid hormones were measured following a standardized protocol.

Results

After adjustment for age and race-ethnicity, higher cadmium levels were associated with higher levels of total testosterone, total estradiol, sex hormone-binding globulin, estimated free testosterone, and estimated free estradiol (each p-trend < 0.05). After additionally adjusting for smoking status and serum cotinine, none of the hormones maintained an association with urinary cadmium (each p-trend > 0.05).

Conclusion

Urinary cadmium levels were not associated with sex steroid hormone concentrations in a large nationally representative sample of US men.
Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility
Authors: Peddinti Divyaswetha , Nanduri Bindu , Kaya Abdullah , Feugang Jean M , Burgess Shane C , Memili Erdogan
Published: February 2008

Background

Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder.

Results

Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G2/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa.

Conclusion

This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype.
Martin Heidegger, Hannah Arendt and the Politics of Remembrance
Authors: Barash Jeffrey Andrew
Published: February 2008

I The intellectual relations between Heidegger and Arendt

The publication of the correspondence between Martin Heidegger and Hannah Arendt in Germany in 1998 contributed new insight into the relations between these two 20th century thinkers. Arendt was Heidegger's student in Marburg in the mid-1920s and the correspondence has confirmed the intimate character of their relationship during this period. Subsequently, Arendt moved to Heidelberg to work with Karl Jaspers. Following Heidegger's support of the Hitler regime as rector of Freiburg University in 1933–1934, communication ceased between Arendt and Heidegger and, during these years, Arendt emigrated, first to France and then to the United States. After the Second World War, the silence between them continued for a period of five years. During this period Arendt published an article highly critical of Heidegger's writings, entitled “What is Existenz-philosophy?” (1946), in which she argued that Heidegger's thought belonged to the contemplative metaphysical tradition inaugurated by Plato that she saw it as her task to overcome. The Hannah Arendt – Martin Heidegger Briefwechsel has also documented the fact that in February 1950 Arendt and Heidegger once again resumed their friendship, which lasted for the remainder of their lives.
Handmade Pottery and Social Change: The View from Late Roman Cyprus
Authors: Rautman Marcus
Published: February 2008

Technological and stylistic change in pottery-making reflects myriad material, social and economic conditions. The adoption of wheel-based pottery techniques in the east Mediterranean generally is seen to reflect rising craft specialization and social complexity in the Middle and Late Bronze Age. There is less agreement about the subsequent continuity or re-emergence of handmade pottery, especially during times of dramatic cultural change. Recent discussions of Handmade Burnished Ware in south Greece in the LBA has explored diffusionist and indigenous explanations to account for this phenomenon. A small group of handmade wares in Cyprus in the seventh century AD offers a broadly analogous situation that finds parallels throughout the Late Roman empire. Comparison of these two handmade pottery traditions emphasizes the importance of both social and economic factors underlying their appearance.
Security and Settlement in the Mediaeval and Post-Mediaeval Peloponnese, Greece
Authors: Forbes Hamish
Published: February 2008

Two recent publications have questioned the hypothesis that insecurity explains the later Ottoman period settlement pattern in the Greek Peloponnese. The present article re-examines the arguments against the demographic retreat hypothesis, focusing particularly on the evidence from a small case-study area, the peninsula of Methana. While previous discussion depended on historical documents, the present study incorporates material cultural and ethnographic evidence. It is argued that simple altitude zonation of settlements is an inadequate indicator of insecurity: the relationship of settlement to geomorphology, and non-settlement elements, such as hidden storage structures and details of house construction, contribute important evidence. However, the understanding of the meanings of all these elements is dependent on local ethnographic sources, especially oral histories. The article concludes that a genuine fear of attack explains the Methana settlement pattern, despite a lack of evidence that the fear was justified.
Modern Black Churchgoers in Miami-Dade County, Florida
Authors: Smith-Cavros Eileen M.
Published: February 2008

Leaving behind rural, land, and sea-dependent, and strongly place-based existences, many Blacks immigrated to Miami, Florida from the rural United States south and from the Bahamas during the first half of the twentieth century. This Black diaspora retains contacts, from sister-church relationships, to family ties, to the deep power of memory, that connect these Miami settlers to their ‘homelands’. This research was ethnographically based and took place among churchgoing Blacks in Miami. Research included participant observation at various churches in addition to over fifty interviews with congregants framed by three in-depth case studies. The findings revealed connections to the natural environment among churchgoing Blacks influenced by these place-centered memories of their youth. From their love of plants to knowledge of agriculture, fishing and land-use patterns to the concept of sharing food and self-sufficiency, their rural and/or island roots had profound impacts on how these subjects perceived the interaction between people and nature. The interpretations of nature that sprang from the diasporic experience were manifested in environmental attitudes, concerns, and select activism that demonstrated the potential to affect positively urban and suburban neighborhoods and nature.
Guest Editors' Preface
Authors: Meyer Birgit , Hughes Stephen
Published: February 2008

This special issue of Postscripts addresses the interace of religion and film by exploring both hos religion is deployed through film and how film is utilized in service of religion. The issues is based on a workshop, Mediating Religion and Film in a Post-Secular World held June 16-17, 2005, at the University of Amsterdam.
Development of Genetic and Genomic Research Resources for Brachypodium distachyon, a New Model System for Grass Crop Research
Authors: Garvin David F. , Gu Yong‐Qiang , Hasterok Robert , Hazen Samuel P. , Jenkins Glyn , Mockler Todd C. , Mur Luis A. J. , Vogel John P.
Published: February 2008

Grass crop genomics research frequently is hindered by large genome sizes and polyploidy. While rice is an attractive system for grass genomics due to its small genome size and available genome sequence, it is not particularly well‐suited as a robust model system for all grass crops. The wild grass species Brachypodium distachyon (L.) P. Beauv. (Brachypodium) has recently gained favor as a new model system for grass crop genomics research because it possesses a suite of biological traits desired in a model system. Further, it is more closely related to the large and diverse group of cool season grass crops than is either rice (Oryza sativa L.) or sorghum [Sorghum bicolor (L.) Moench.], the second grass crop species whose genome has been sequenced. Thus, by virtue both of its biological attributes and its evolutionary history, Brachypodium fills an important gap in grass crop genomics research. A surge in interest in Brachypodium has led to rapid and significant advances in the acquisition of knowledge and development of resources needed to exploit this species as a model system, including. the impending completion of a draft nuclear genome sequence of Brachypodium. Integration of diverse genetic and genomic resources developed or under development for Brachypodium with the genome sequence will encourage further adoption of this species as a bona fide model plant system.
Genomic Origins of Potato Polyploids: GBSSI Gene Sequencing Data
Authors: Spooner David M. , Rodríguez Flor , Polgár Zsolt , Ballard Harvey E. , Jansky Shelley H.
Published: February 2008

Chromosome pairing relationships within cultivated potato (Solanum tuberosum) and its wild tuber‐bearing relatives (Solanumsect.Petota) have been interpreted by genome formulas, developed in the early 1900s, through techniques of classic meiotic analysis of interspecific hybrids. Here we reexamine potato genome hypotheses with the first phylogenetic analysis of all major genomes of sect.Petotausing cloned DNA sequences of the single‐copy nuclear gene GBSSI (waxy). Our results provide the first molecular confirmation of allopolyploidy in wild potato. They both support prior hypotheses and identify novel genome origins never before proposed. The data will be useful to help design crossing strategies to incorporate wild species germplasm into cultivated potato.
Suspected swainsonine poisoning in a Belgian horse
Authors: Nollet H. , Panter K. , Vanschandevijl K. , Lefere L. , Stegelmeier B. , Deprez P.
Published: February 2008

The case of a horse with acute symptoms of excitement, exaggerated fright reactions and trembling is presented. In addition to these cerebral symptoms, mild cerebellar ataxia and a renal tubular lesion were diagnosed. Suspected swainsonine poisoning was confirmed by the presence of the toxin (154 ng/ml) in the serum sample taken immediately after admission. A good recovery was seen after fluid therapy with supplementation of potassium, a dopamine drip and administration of diazepam. The effects of the toxin, by inhibiting the lysosomal enzyme α‐mannosidase and mimicking the genetic mannosidosis, are discussed.
Rhodococcus equi pneumonia in an adult horse
Authors: Waldridge B. M. , Morresey P. R. , Loynachan A. T. , Reimer J. , Riddle W. T. , Williams N. M. , Bras R.
Published: February 2008

A 20‐year‐old, Thoroughbred mare in the fifth month of gestation was examined for weight loss, pyrexia and lethargy. Physical examination, ultrasonography and radiography revealed a severe abscessing pneumonia and a dead fetus. The mare did not respond to symptomatic treatment and died suddenly. Necropsy revealed multifocal pulmonary abscessation.

Rhodococcus equi was isolated from the lungs, liver and kidneys. Specific immune function of the mare and presence of the virulence associated protein A (VapA) of the R. equi isolated was not determined. It is likely that immunosuppression is required for systemic R. equi infections in adult horses; however, it is unknown if VapA is necessary to produce disease in adult horses.
Quality of equine veterinary care: Where can it go wrong? A conceptual framework for the quality of equine healthcare, based on court cases against equine practitioners in The Netherlands
Authors: Loomans J. B. A. , van Weeren P. R. , Vaarkamp H. , Stolk P. W. Th. , Barneveld A.
Published: February 2008

Quality control and client satisfaction are topics of considerable current interest in both human and veterinary healthcare. Crucial to this discussion is a proper definition of ‘quality of care’. This study applied, to (equine) veterinary care, a conceptual framework designed for assessing the quality of human healthcare and featuring structural deficiency, procedural inadequacy and disappointing outcome as key elements. This was done using court cases against equine practitioners as a yardstick for client dissatisfaction.

Applying a system for evaluating the quality of healthcare may be a good way of monitoring and improving (equine) veterinary services, particularly once reliable indices for client satisfaction have been validated.
Gerald Feldman
Authors: Markovits Andrei S.
Published: February 2008

This is not the place for me to express my boundless admiration for

the scholarship of our dear friend and colleague, Gerald Feldman,

who passed from this world far too early in the fall of 2007. Nor

would I find it appropriate to address my personal friendship with

Gerry in these pages. I have done both elsewhere and—most important

to me—privately to Gerry's widow, Norma. Nevertheless, I do

find it more than appropriate to mention Gerry's involvement with

German Politics and Society. I was deeply moved and much honored

by Jeff Anderson's request to do so.
Simple Methodology for Heck Arylation at C‐8 of Adenine Nucleosides
Authors: Lagisetty Pallavi , Zhang Li , Lakshman Mahesh K.
Published: February 2008

A simple method for the arylation of 8‐vinyladenine nucleoside derivatives is reported. With a broad set of aryl iodides and bromides, the reaction is catalyzed by the simple combination palladium acetate/tris(o‐tolyl)phosphine/triethylamine [Pd(OAc)2/(o‐tol)3P/Et3N]. As expected, aryl chlorides are more difficult coupling partners but some undergo reactions with more exotic catalysts. Although trans‐olefins are the major products, minor amounts of cis‐isomers are detected in some cases, and a post‐arylation mechanism for their formation is proposed. Finally, by subtle catalyst modulation chemoselective N‐arylation of the nucleoside can be achieved in the presence of the vinyl moiety.
Palladium‐Catalyzed/Lewis Acid‐Promoted Alkene Dimerization and Cross‐Coupling with Alcohols via CH Bond Activation
Authors: Jiang Yi‐Jun , Tu Yong‐Qiang , Zhang En , Zhang Shu‐Yu , Cao Ke , Shi Lei
Published: February 2008

The cross‐couplings of alcohols to alkenes with the palladium/Lewis acid system are reported. This reaction occurs in a successive alkene dimerization, direct CH activation of alcohol and sp3sp3 bond forming sequence via an interesting domino process.
Eight‐Step Synthesis of Routiennocin
Authors: Matsumoto Kenji , Kozmin Sergey A.
Published: February 2008

Routiennocin is a member of a family of polycyclic pyrrole ether antibiotics that simultaneously uncouple oxidative phosphorylation and inhibit ATPase as a result of selective complexation of divalent metal ions. We describe a concise synthesis of routiennocin with the longest linear sequence of 8 steps. Our synthesis features a unique bi‐directional strategy, which entails a sequential ring‐opening/cross metathesis of a highly strained cyclopropenone acetal. This approach enables rapid and highly convergent assembly of the fully extended polyketide subunit of this natural product from readily available homoallylic alcohol precursors.
Induction of Columnar and Smectic Phases for Spiropyran Derivatives: Effects of Acidichromism and Photochromism
Authors: Tan Boon‐Hooi , Yoshio Masafumi , Kato Takashi
Published: February 2008

Liquid‐crystalline (LC) properties have been induced in a number of spiropyran derivatives by the addition of methanesulfonic acid. Spiropyran derivatives containing one or two gallic acid moieties with one, two, or three long alkyl chains were prepared. Acid‐induced spiro–protonated‐merocyanine isomerization induced mesomorphism for these materials. Equimolar mixtures of methanesulfonic acid and the spiropyran derivatives with one or two dodecyloxy chains exhibited smectic A phases, whereas the spiropyran derivatives containing the gallic acid moiety with three dodecyloxy chains showed hexagonal columnar phases. On the contrary, photoirradiation of the spiropyran compounds in the bulk liquid state did not lead to the induction of mesomorphism, although the merocyanine form was induced. These results suggest that these merocyanine derivatives with ionic and nonionic moieties cannot simply form nanosegregated LC structures. Complex formation of the merocyanine form with methanesulfonic acid may play a key role in the formation of LC molecular assemblies.
Molecular Design for Reversing the Photoswitching Mode of Turning ON and OFF DNA Hybridization
Authors: Liang Xingguo , Takenaka Nobutaka , Nishioka Hidenori , Asanuma Hiroyuki
Published: February 2008

A new photoswitch for DNA hybridization involving para‐substituted azobenzenes (such as isopropyl‐ or tert‐butyl‐substituted derivatives) with L‐threoninol as a linker was synthesized. Irradiation of the modified DNA with visible light led to dissociation of the duplex owing to the destabilization effect of the bulky substituent on the trans‐azobenzene. In contrast, trans‐to‐cis isomerization (UV light irradiation) facilitated duplex formation. The direction of this photoswitching mode was entirely reversed relative to the previous system with an unmodified azobenzene on D‐threoninol whose trans form turned on the hybridization, and cis form turned it off. Such reversed and reversible photoswitching of DNA hybridization was directly demonstrated by using fluorophore‐ and quencher‐attached oligonucleotides. Furthermore, it was revealed that the cis‐to‐trans thermal isomerization was greatly suppressed in the presence of the complementary strand owing to the formation of the more‐stable duplex in the cis form.
Assessing the default risk by means of a discrete‐time survival analysis approach
Authors: De Leonardis Daniele , Rocci Roberto
Published: February 2008

In this paper, the problem of company distress is assessed by means of a multi‐period model that exploits the potentialities of the survival analysis approach when both survival times and regressors are measured at discrete points in time. The discrete‐time hazards model can be used both as an empirical framework in the analysis of the causes of the deterioration process that leads to the default and as a tool for the prediction of the same event. Our results show that the prediction accuracy of the duration model is better than that provided by a single‐period logistic model. It is also shown that the predictive power of the discrete‐time survival analysis is enhanced when it is extended to allow for unobserved individual heterogeneity (frailty). Copyright © 2008 John Wiley & Sons, Ltd.
Modeling dependencies between rating categories and their effects on prediction in a credit risk portfolio
Authors: Czado Claudia , Pflüger Carolin
Published: February 2008

The internal‐rating‐based Basel II approach increases the need for the development of more realistic default probability models. In this paper, we follow the approach taken in McNeil A and Wendin J 7 (J. Empirical Finance 2007) by constructing generalized linear mixed models for estimating default probabilities from annual data on companies with different credit ratings. The models considered, in contrast to McNeil A and Wendin J 7 (J. Empirical Finance 2007), allow parsimonious parametric models to capture simultaneously dependencies of the default probabilities on time and credit ratings. Macro‐economic variables can also be included. Estimation of all model parameters are facilitated with a Bayesian approach using Markov chain Monte Carlo methods. Special emphasis is given to the investigation of predictive capabilities of the models considered. In particular, predictable model specifications are used. The empirical study using default data from Standard and Poor's gives evidence that the correlation between credit ratings further apart decreases and is higher than the one induced by the autoregressive time dynamics. Copyright © 2008 John Wiley & Sons, Ltd.
Bayesian parameter inference for models of the Black and Scholes type
Authors: Gzyl Henryk , ter Horst Enrique , Malone Samuel W.
Published: February 2008

In this paper, we describe a general method for constructing the posterior distribution of the mean and volatility of the return of an asset satisfying dS=SdX for some simple models of X. Our framework takes as inputs the prior distributions of the parameters of the stochastic process followed by the underlying, as well as the likelihood function implied by the observed price history for the underlying. As an application of our framework, we compute the value at risk (VaR) and conditional VaR (CVaR) measures for the changes in the price of an option implied by the posterior distribution of the volatility of the underlying. The implied VaR and CVaR are more conservative than their classical counterpart, since it takes into account the estimation risk that arises due to parameter uncertainty. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal admission and pricing control problems in service industries with multiple servers and sideline profit
Authors: Son Jae‐Dong , Khojasteh Ghamari Yaghoub
Published: February 2008

This paper deals with the problem of selecting profitable customer orders sequentially arriving at a company operating in service industries with multiple servers in which two classes of services are provided. The first class of service is designed to meet the particular needs of customers; and the company (1) makes a decision on whether to accept or to reject the order for this service (admission control) and (2) decides a price of the order and offers it to an arriving customer (pricing control). The second class of service is provided as a sideline, which prevents servers from being idle when the number of customer orders for the first class is less than the number of servers. This yields the sideline profit. A cost is paid to search for customer orders, which is called the search cost. In the context of search cost, the company has an option whether to conduct the search or not. In this paper, we discuss both admission control and pricing control problems within an identical framework as well as examine the structure of the optimal policies to maximize the total expected net profit gained over an infinite planning horizon. We show that when the sideline profit is large, the optimal policies may not be monotone in the number of customer orders in the system. Copyright © 2008 John Wiley & Sons, Ltd.
Factors affecting corporate environmental strategy in Spanish industrial firms
Authors: Fraj‐Andrés Elena , Martínez‐Salinas Eva , Matute‐Vallejo Jorge
Published: February 2008

During the last 30 years, environmental issues have become very important for governments, consumers and companies. Firms, aware of their environmental responsibilities, have started to show an important commitment to society and the natural environment, developing environmentally friendly strategies. However, the factors that determine the choice of environmental strategies are still unclear. They range from ethical motivations to social, legislative and competitive factors. This study analyses the main antecedents that influence firms' ecological behaviour, distinguishing between environmental orientation and environmental strategies. The hypotheses proposed in this study are analysed by means of a structural equation model on a sample of 235 industrial firms. The results reveal that competitive motivations and management commitment are the most important factors explaining why firms incorporate environmental issues into their strategic planning process. Moreover, management commitment is a critical factor for firms because managers' perception about customers' ecological concern directly influences firms' environmental behaviour. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Ligand‐Induced Flocculation of Neurotoxic Fibrillar Aβ(1–42) by Noncovalent Crosslinking
Authors: Hetényi Anasztázia , Fülöp Lívia , Martinek Tamás A. , Wéber Edit , Soós Katalin , Penke Botond
Published: February 2008

Aggregation of the amyloid‐β (Aβ) peptides has a pivotal role in Alzheimer’s disease (AD). Small molecules and short peptides/peptidomimetics can exert their full protective effects against Aβ within a short time‐frame, but the exact mechanism of action is unclear. Time‐dependent NMR spectroscopic binding and replacement experiments were carried out for peptide LPFFD and thioflavine T (ThT) on neurotoxic fibrillar Aβ(1–42), which revealed transient binding behavior for both compounds, and complex time‐dependent features in the replacement experiments. The results of particle size measurements through the use of diffuse light‐scattering and transmission electron microscopy support the conclusions that the studied ligands induced interfibrillar association on a short timescale, which explains the NMR spectroscopic binding and replacement results. ζ‐Potential measurements revealed a slightly increased electrostatic stability of the Aβ fibrils upon ligand binding; this suggests that the interfibrillar assembly is driven by specific noncovalent cross‐linking interactions. A specific surface and mobility decrease due to the ligand‐induced flocculation of the Aβ fibrils can explain the neuroprotective effects.
Activity‐Based Protein Profiling: New Developments and Directions in Functional Proteomics
Authors: Uttamchandani Mahesh , Li Junqi , Sun Hongyan , Yao Shao Q.
Published: February 2008

Proteomic screening has become increasingly insightful with the availability of novel analytical tools and technologies. Detailed analysis and integration of the profound datasets attained from comprehensive profiling studies are enabling researchers to dig deeper into the foundations of genomic and proteomic networks, towards a clearer understanding of the intricate cellular circuitries they manifest. The major difficulty often lies in correlating the patho/physiological state presented with the underlying biological mechanisms; therefore, identification of causal variants as therapeutic targets is extremely important. Herein, we will describe methods that address this challenge through activity‐based protein profiling, which applies chemical probes to the comparison and monitoring of protein dynamics across complex proteomes. Over recent years such activity‐based probes have been creatively augmented with applications in gel‐based separations, microarrays and in vivo imaging. These developments offer a newfound ability to characterise and differentiate cells, tissues and proteomes through activity‐dependent signatures; this has expanded the scope and impact of activity‐based probes in biomedical research.
Intraannular Savige–Fontana Reaction: One‐Step Conversion of One Class of Monocyclic Peptides into Another Class of Bicyclic Peptides
Authors: May Jonathan P. , Perrin David M.
Published: February 2008

Cyclisation and cross‐linking strategies are important for the synthesis of cyclic and bicyclic peptides. These macrolactams are of great interest due to their increased biological activity compared to linear analogues. Herein, we describe the synthesis of a cyclic peptide containing an Hpi toxicophore, reminiscent of phakellistatins and omphalotins. The first intraannular cross‐linking of such a peptide is then presented: using neat TFA to catalyse a Savige–Fontana tryptathionylation, the Hpi‐containing peptide is converted to a bicyclic amatoxin analogue. As such, this methodology represents an efficient cyclisation method for cross‐linking peptides and exposes a heretofore unrealised relationship between two different classes of peptide natural products. This finding increases the degree of potential chemical space for library generation.
Selective Inclusion of Cu+ and Ag+ Electron‐Rich Metallic Cations within Supramolecular Polyoxometalates Based on {AsW9O33}{Mo3S4} Combinations
Authors: Duval Sylvain , Pilette Marie‐Anne , Marrot Jérôme , Simonnet‐Jégat Corine , Sokolov Maxim , Cadot Emmanuel
Published: February 2008

Coordination of the [Mo3S4(H2O)9]4+ cluster with the trivacant [AsW9O33]9− ion gives the supramolecular complex [{(H4AsW9O33)4(Mo3S4{H2O}5)}2]12− (1) in good yield. The structure of 1 shows that two [H4AsW9O33]5− subunits sandwich a single central [Mo3S4(H2O)5]4+ ion to give a basic monomeric unit [(H4AsW9O33)2{Mo3S4(H2O)5}]6−. In the solid sate, a supramolecular dimeric association is evidenced that consists of two [(H4AsW9O33)2{Mo3S4(H2O)5}]6− units held together by twelve hydrogen bonds and four S⋅⋅⋅S contacts. Complex 1 reacts with NaAsO2, AgNO3 and CuI to give compounds 2, 3 and 4, respectively. X‐ray structural analysis reveals that the molecular arrangements of 2 to 4 are closely related to the parent structure of 1. {AsOH}2+, Ag+ and Cu+ ions are located on three distinct pairs of sites. Two hanging {AsOH}2+ groups in 2 are symmetrically attached to two opposite {AsW9O33} subunits. Complex 3 is the first example of an Ag/{Mo3S4} combination in which the environment of the two equivalent Ag+ cations is remarkable for containing two sulfur atoms belonging to {Mo3S4}, two oxygen and one central arsenic atom of the {AsW9O33} subunits. Potentiometric titration shows that the addition of Ag+ ions is quantitative and occurs in two successive steps (K1=4.1×106 and K2=2.3×105 L mol−1), which is consistent with the retention of the supramolecular cluster in solution. The structure of 4 reveals a single copper atom embedded in the central part of the dimer. The Cu+ cation is bound to four sulfur atoms to complete a cuboidal moiety. UV/Vis studies in solution indicate that the stability of the dimeric assemblies of 2, 3 and 4 is significantly enhanced by the presence of Cu+ or Ag+ ions, which act as additional coordination linkers within the supramolecular cluster. The anions 1 to 4 were characterised by 183W NMR spectroscopy in solution. The 10‐line spectra recorded for each of them are consistent with an averaged C2h molecular symmetry in solution.
Hydration of Lanthanoid(III) Ions in Aqueous Solution and Crystalline Hydrates Studied by EXAFS Spectroscopy and Crystallography: The Myth of the “Gadolinium Break”
Authors: Persson Ingmar , D'Angelo Paola , De Panfilis Simone , Sandström Magnus , Eriksson Lars
Published: February 2008

The structures of the hydrated lanthanoid(III) ions including lanthanum(III) have been characterized in aqueous solution and in the solid trifluoromethanesulfonate salts by extended X‐ray absorption fine structure (EXAFS) spectroscopy. At ambient temperature the water oxygen atoms appear as a tricapped trigonal prism around the lanthanoid(III) ions in the solid nonaaqualanthanoid(III) trifluoromethanesulfonates. Water deficiency in the capping positions for the smallest ions starts at Ho and increases with increasing atomic number in the [Ln(H2O)9−x](CF3SO3)3 compounds with x=0.8 at Lu. The crystal structures of [Ho(H2O)8.91](CF3SO3)3 and [Lu(H2O)8.2](CF3SO3)3 were re‐determined by X‐ray crystallography at room temperature, and the latter also at 100 K after a phase‐transition at about 190 K. The very similar Ln K‐ and L3‐edge EXAFS spectra of each solid compound and its aqueous solution indicate indistinguishable structures of the hydrated lanthanoid(III) ions in aqueous solution and in the hydrated trifluoromethanesulfonate salt. The mean LnO bond lengths obtained from the EXAFS spectra for the largest ions, La–Nd, agree with estimates from the tabulated ionic radii for ninefold coordination but become shorter than expected starting at samarium. The deviation increases gradually with increasing atomic number, reaches the mean LnO bond length expected for eightfold coordination at Ho, and increases further for the smallest lanthanoid(III) ions, Er–Lu, which have an increasing water deficit. The low‐temperature crystal structure of [Lu(H2O)8.2](CF3SO3)3 shows one strongly bound capping water molecule (LuO 2.395(4) Å) and two more distant capping sites corresponding to LuO at 2.56(1) Å, with occupancy factors of 0.58(1) and 0.59(1). There is no indication of a sudden change in hydration number, as proposed in the “gadolinium break” hypothesis.
Interpenetrated Three‐Dimensional MnIIMIII Ferrimagnets, [Mn(4dmap)4]3[M(CN)6]2⋅10 H2O (M=Cr, Mn): Structures, Magnetic Properties, and Pressure‐Responsive Magnetic Modulation
Authors: Kaneko Wakako , Mito Masaki , Kitagawa Susumu , Ohba Masaaki
Published: February 2008

Two novel cyanide‐bridged ferrimagnets, [Mn(4dmap)4]3[M(CN)6]2‐ ⋅10 H2O (4dmap=4‐dimethylaminopyridine, M=Cr (1) and Mn (2)), have been prepared from the reaction of MnCl2⋅4 H2O, a monodentate coligand (4dmap), with K3[M(CN)6]. X‐ray crystallographic results show that these are isomorphous, and form a unique twofold interpenetrated three‐dimensional framework with a triconnected 6.102 net. The framework contains two types of one‐dimensional channel: hexagonal channels based on a cyanide‐bridged Mn6M6 hexagon, and triangle channels segmented by CN‐Mn‐NC linkages, which are filled with lattice water molecules. The dimethylamino groups of the 4dmap coligands are located around a pore and form the basic inner space. Variable‐temperature X‐ray powder diffraction and thermogravimetric analysis results show that the frameworks of both compounds are susceptible to dehydration through the loss of strongly hydrogen‐bonded lattice water molecules. Magnetic measurements on both compounds show a ferrimagnetic ordering occurs at low temperature, TC=17 K for 1 and 6 K for 2. Application of hydrostatic pressure showed a positive effect on the magnetic ordering. Both values of TC increased linearly, to 25 K for 1 and 15 K for 2 at 1.0 GPa. The magnetic properties of both compounds were reversibly modulated by the external stress.
Efficient CO2 Capturer Derived from As‐Synthesized MCM‐41 Modified with Amine
Authors: Yue Ming Bo , Sun Lin Bing , Cao Yi , Wang Ying , Wang Zhu Ji , Zhu Jian Hua
Published: February 2008

A new strategy to synthesize a highly efficient CO2 capturer by incorporating tetraethylenepentamine (TEPA) into as‐synthesized MCM‐41 (AM) is reported. The amine guest can be distributed in the micelle of the support, forming a web within the mesopore to trap CO2 molecules and resulting in a high adsorption capacity for CO2 up to 237 mg g−1. Four samples of the as‐synthesized MCM‐41 with a different amount or type of surfactant are employed as supports to investigate the influence of micelles on the CO2 adsorption, and the spokelike structure of the micelle in the channel of the support is proven to be essential to the distribution of guest amine. Among these supports, the AM sample is the most competitive due to the advantages of energy and time saving in preparation of the support along with the resulting higher CO2 adsorption capacity. At the optimal loading of 50 wt % TEPA, the AM‐50 sample exhibits a high adsorption capacity of 183 mg g−1 in the sixth adsorption cycle at 5 % CO2 concentration.
Fluorine⋅⋅⋅ and π⋅⋅⋅Alkali Metal Interactions Control in the Stereoselective Amide Enolate Alkylation with Fluorinated Oxazolidines (Fox) as a Chiral Auxiliary: An Experimental and Theoretical Study
Authors: Sini Gjergji , Tessier Arnaud , Pytkowicz Julien , Brigaud Thierry
Published: February 2008

The α‐alkylation of amide enolates by using a pseudo‐C2 symmetry trans 4‐phenyl‐2‐trifluoromethyloxazolidine (trans‐Fox) as a chiral auxiliary occurs with an extremely high diastereoselectivity (>99 % de). The origin of this excellent stereocontrol was investigated by an experimental and theoretical (DFT) study. With this trans chiral auxiliary, both F⋅⋅⋅metal and π⋅⋅⋅metal interactions compete to give the same diastereomer through Re face alkylation of the enolate. A 5.5 kcal mol−1 energy difference found between the Re face and the Si face attack transition states is consistent with the complete diastereoselectivity that has been experimentally achieved. On the other hand, in the case of the cis chiral auxiliary (cis‐Fox) the competition between the F⋅⋅⋅metal and π⋅⋅⋅metal interactions is unfavourable to the diastereoselectivity. In this case, the Re face and the Si face attack transition states were found to be nearly isoenergetic (0.3 kcal mol−1 difference), which is in good agreement with the very low diastereoselectivity observed.
Towards the Rational Design of MRI Contrast Agents: Electron Spin Relaxation Is Largely Unaffected by the Coordination Geometry of Gadolinium(III)–DOTA‐Type Complexes
Authors: Borel Alain , Bean Jonathan F. , Clarkson Robert B. , Helm Lothar , Moriggi Loïck , Sherry A. Dean , Woods Mark
Published: February 2008

Electron‐spin relaxation is one of the determining factors in the efficacy of MRI contrast agents. Of all the parameters involved in determining relaxivity it remains the least well understood, particularly as it relates to the structure of the complex. One of the reasons for the poor understanding of electron‐spin relaxation is that it is closely related to the ligand‐field parameters of the Gd3+ ion that forms the basis of MRI contrast agents and these complexes generally exhibit a structural isomerism that inherently complicates the study of electron spin relaxation. We have recently shown that two DOTA‐type ligands could be synthesised that, when coordinated to Gd3+, would adopt well defined coordination geometries and are not subject to the problems of intramolecular motion of other complexes. The EPR properties of these two chelates were studied and the results examined with theory to probe their electron‐spin relaxation properties.
Enantioselective Formation of tert‐Alkylamines by Desymmetrization of 2‐Substituted Serinols
Authors: Hong Mi Sook , Kim Tae Woo , Jung Byunghyuck , Kang Sung Ho
Published: February 2008

Novel enantioselective desymmetrization of 2‐substituted 2‐amino‐1,3‐propanediols has been established to generate asymmetric quaternary carbon centers comprising an amino group. Enantioselective as well as chemical conversion proved to be greatly dependent on the protecting group of the amino group in the substrate, desymmetrizing reagent, base, solvent, and naturally, catalyst. The highly effective desymmetrization has been implemented by using N‐benzoylated substrates with benzoyl chloride and triethylamine in the presence of tetraphenylbisoxazoline (24)–CuCl2 complex in THF at ambient temperature. An extensive survey of catalysts revealed that dimethylmalonate‐bridged bisoxazoline–CuCl2 complexes were superior. Among them, the tetraphenylbisoxazoline (24)–CuCl2 complex turned out to work most efficiently with a wide array of the substrates. All the examined substrates, with the exception of 2‐phenylserinol 36, were desymmetrized in the presence of 24–CuCl2 complex to give high enantioselectivities ranging from 85 to 95 % ee. Complementary use of the diisopropylbisoxazoline (22)–CuCl2 complex has remedied the mediocre desymmetrization of 36 to give a significantly improved enantioselectivity from 63 to 83 % ee.
A Persistent Alkylaluminum Peroxide: Surprising Stability of a Molecule with Strong Reducing and Oxidizing Functions in Close Proximity
Authors: Uhl Werner , Jana Barun
Published: February 2008

The reaction of the β‐diketiminato coordinated aluminum dihydride, [{HC[C(Me)NC6H5]2}AlH2] (1) with bis(trimethylsilyl)methyllithium afforded the monoalkylaluminum derivative [{HC[C(Me)NC6H5]2}Al(H)CH(SiMe3)2] (2) by the precipitation of lithium hydride. Interestingly, treatment of 2 with tert‐butyl hydrogenperoxide did not result in the formation of the simple oxidation product containing a hydroxo or alkoxo group, instead, elemental hydrogen was released and the hydrido ligand attached to aluminum was replaced by an intact tert‐ butylperoxo group. The AlC bond, which normally is extremely sensitive towards an attack of oxygen, was not affected. Hence, the product exhibits quite conflicting chemical properties in a close proximity: a strongly reducing AlC bond beside an oxidizing peroxo group.
Evaluation of a decision support training effectiveness measure
Authors: Bohler Jeffrey , Hall Dianne
Published: February 2008

Resource constraints affect the US Department of Defense's ability to simultaneously sustain current operations and recapitalize for future challenges. An assumption is that decision support training may improve resource allocation decisions; however, few instruments are available to measure the effectiveness of decision support training to verify that assumption. The purpose of this research is to evaluate an instrument to measure decision support training effectiveness. Using data collected from a resource allocation simulation, we found a significant positive relationship between decision support training and outcomes in a controlled field study involving a complex problem. Thus, in the proper context, the resource allocation simulation described herein may be a reliable measure of decision support training effectiveness. Copyright © 2008 ASAC. Published by John Wiley & Sons, Ltd.
Stable Small Gas‐Phase Dianion C7H22−
Authors: ZHANG Cong‐Jie , LIANG Jin‐Xia , CAO Ze‐Xing
Published: February 2008

The geometries and vibrational frequencies of C7H22− and C7H32− dianions, as well as their corresponding anions were investigated theoretically using HF, MP2, CCSD and CISD methods. The lowest energy structures are C2C(H2)C42− and C2CHCHCHC22− for C7H22− and C7H32− dianions, respectively. Analysis of possible detachment channels of the two structures indicates that the two isomers are stable with respect to fragmentation into two monoanions. However, the vertical and adiabatic detachment energies of the two structures show that C2C(H2)C42− is electronically stable, while C2CHCHCHC22− is not.
Titration Calorimetry Applied to the Thermokinetics Study of Consecutive First‐order Reactions
Authors: SHI Jing‐Yan , LI Jie , WANG Zhi‐Yong , LIU Yu‐Wen , WANG Cun‐Xin
Published: February 2008

The thermokinetic mathematical models for consecutive first‐order reactions in titration period and the stopped‐titration reaction period were proposed for titration calorimetry, based on which, thermodynamic parameters (reaction enthalpies, ΔrHm1and ΔrHm2) and kinetic parameters (rate constants, k1 and k2) of the consecutive first‐order reactions could be obtained by directly simulating the calorimetric curve from a single experiment with the method of nonlinear least squares regression (NLLS). The reliability of the model has been verified by investigating the reaction of the saponification of diethyl succinate in an aqueous ethanol solvent.
Density Functional Theory Study of Red‐shifted Hydrogen Bonds of 4‐Pyridinemethanol with Water
Authors: LI Quan , CAI Jing , CHEN Jun‐Rong , ZHAO Ke‐Qing
Published: February 2008

The hydrogen bonds of 1:1 and 1:2 complexes formed between 4‐pyridinemethanol and water have been investigated using a density functional theory (DFT) method and 6‐311++G∗︁ ∗︁ basis set, and three and eight stable geometries have been obtained for 1:1 and 1:2 complexes, respectively. The interaction energy is −20.536 and −44.256 kJ/mol for the most stable 1:1 and 1:2 complexes, respectively, after the basis set superposition error and zero‐point corrections. The formation of OH···N(O) hydrogen bonds makes OH symmetric stretching modes in the complexes red‐shifted relative to those of the monomer. The natural bond orbit analysis indicates that the intermolecular charge transfer between 4‐pyridinemethanol and water is 0.02642 e and 0.03813 e for the most stable 1:1 and 1:2 complexes, respectively. In addition, TD‐B3LYP/6‐311++G∗︁ ∗︁ calculations show that formation of water‐OH···N and water‐OH···OH hydrogen bonds makes maximum absorbance wavelength λmax blue‐shifted 8–16 nm and red‐shifted 4–11 nm compared to that of 4‐pyridinemethanol monomer molecule, respectively.
C–H···Cl Hydrogen Bond and π‐ π Interaction Based Two 3D Supramolecular Architectures of Cu(II) and Co(II) Complexes with Chiral 1,2‐Bis(benzimidazol‐2‐yl) ethane Ligand Containing 2D Grids
Authors: JI Bao‐Ming , WANG Xiu‐Ge , XU Chen , MA Ning , MIAO Shao‐Bin
Published: February 2008

Two new complexes, CuLCl2·2EtOH (1) and CoLCl2 (2) [L= (S,S)‐1,2‐bis(1‐methylbenzimidazol‐2‐yl)‐1,2‐bis‐(methoxy)ethane], have been synthesized in ethanol solution and structurally characterized by single crystal X‐ray diffraction analysis. The crystal structure data indicated that ligand L was coordinated to copper(II) ion as a tridentate ligand using [N, N, O] atoms, while it was coordinated to cobalt(II) ion as a bidentate ligand using [N, N] atoms. The most striking common feature of the structures of both complexes is the formation of 2D grid structures, which are formed by six and three types of intermolecular hydrogen bonds for complexes 1 and 2. These 2D grids are extended by CH···Cl hydrogen bonds and π‐π stacking interactions, leading to a 3D framework.