bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Dienol‐Benzol‐Umlagerung von Allyldienolen: aromatische [1,2]‐, [3,3]‐ und [3,4]‐sigmatropische Umlagerungen
Authors: Hansen H.‐J. , Sutter B. , Schmid H. 
Published: February 2011

AbstractThe dienol‐benzene rearrangement of syn and anti‐4‐allyl‐4‐methylcyclohexa‐2,5‐dien‐1‐ol (syn and anti 15) occurs by formation of a benzonium ion intermediate in p‐toluene‐sulphonic acid in ether below 0° and leads to a mixture of 2‐, 3‐ and 4‐allyltoluenes in the ratio 54:10:36. By the introduction of 14C‐, D‐ and methyl labelled dienols it is shown that only the allyl group migrates and that this rearrangement is an intramolecular, one‐step process. The formation of 2‐allyltoluene occurs with retention, whereas the 3‐ and 4‐allyltoluenes are formed by inversion of the carbon skeleton of the migrating allyl group. These rearrangements can be therefore classified as suprafacial, aromatic sigmatropic reactions of the order [1,2], [3,3] and [3,4]. The transition state can be postulated as representing a positively charged complex consisting of interacting allyl and tolyl radicals. The interaction of the two parts is controlled by the symmetry of the highest occupied π‐orbitals (ψ3 for toluene and ψ2 for the allyl group) in agreement with the Woodward‐Hoffmann rules. The better “distribution” of the charge in the transition state of these reactions in comparison to the ground state is chiefly responsible for the CoPE‐like [3,3] sigmatropic reaction occurring at low temperatures. In general, sigmatropic reactions in charged systems are faster.The rearrangement of syn and anti 2‐allyl‐2‐methylcyclohexa‐3,5‐dien‐1‐ol (syn and anti 28) gives results similar to those obtained with the para‐allyldienols.The thermal rearrangement of 15 and 28 gives 3‐allyltoluene by a [3,3] sigmatropic Cope rearrangement followed by elimination of water.
Thyrocalcitonin. II. Struktur von α‐Thyrocalcitonin
Authors: Neher R. , Riniker B. , Zuber H. , Rittel W. , Kahnt F. W. 
Published: February 2011

AbstractThe highly active peptide hormones isolated from pig thyroids – i.e. α‐thyrocalcitonin and its sulfoxide, containing 32 amino acid residues – were subjected to sequence studies using chemical and enzymatic methods. On the basis of these studies the following structure was derived for α‐thyrocalcitonin:magnified imageIn the α‐thyrocalcitonin sulfoxide (designated formerly as β‐thyrocalcitonin) the methionine residue is replaced by methionine sulfoxide.
Steroide und Sexualhormone: 234. Mitteilung: Synthese cis‐ständiger 1,2;4,5‐Dioxido‐3‐oxo‐ und 1,3,5‐Trihydroxyandrostane
Authors: Eggart Fr L. G. , Keller P. , Lehmann C. , Wehrli H. 
Published: February 2011

AbstractThe synthesis of the two stereoisomeric diepoxyketones 9 and 22, and of the tetrols 7 and 20 is described. Compound 7 contains the ring‐A‐triol partial structure characterising some naturally occurring cardiac glycosides.
Synthèse par la méthode de Merrifield d'un octapeptide faisant partie du lysozyme de blanc d' œuf de Poule (enchaǐnement Cys64 → Gly71)
Authors: Jollès Pierre , Jollès Jacqueline 
Published: February 2011

AbstractThe solid‐phase peptide synthesis of an octapeptide contained in hen egg‐white lysozyme (sequence Cys (residue 64) to Gly (residue 71)) is reported. Each step of the synthesis was verified by amino acid analysis. Three main reaction products were obtained. The octapeptide (50% of the reaction products) was purified by two chromatographies on Dowex 50 × 2. The purified peptide was digested by an aminopeptidase and degradated by means of Edman' s method; this latter procedure has shown that the purified octapeptide still contained around 10% of a shorter peptide.
Temperaturverhalten des Circulardichroismus und Konformationsanalyse einiger nichtkonjungierter ungesättigter Oxoverbindungen, und auf dem Steroid‐Symposium in Mailand, Mai 1966
Authors: Snatzke G. , Schaffner K. 
Published: February 2011

Abstract– The circular dichroism of some non‐conjugated unsaturated carbonyl compounds, which are conformationally mobile, has been measured at +20° and at about −178°. Specifically for the steroidal compounds 1 and 2 and the monocyclic aldehyde 14, their substituted analogs 4–6, 9–11, and 15–19, respectively, as well as for the aliphatic ketone 21 the CD. temperature gradients are interpreted in terms of the preferred conformations. In the case of the β,γ‐unsaturated aldehydes 1 and 14, a correlation of these results with the photolytic decarbonylation from the excited singlet states is discussed.
Prolonged expression of the γ‐H2AX DNA repair biomarker correlates with excess acute and chronic toxicity from radiotherapy treatment
Authors: Bourton Emma C. , Plowman Piers N. , Smith Daniel , Arlett Colin F. , Parris Christopher N. 
Published: February 2011

AbstractThe normal tissue tolerance levels to fractionated radiotherapy have been appreciated by a century of careful clinical observations and radiobiological studies in animals. During clinical fractionated radiotherapy, these normal tissue tolerance levels are respected, and severe sequelae of radiotherapy are avoided in the majority of patients. Notwithstanding, a minority of patients experience unexpectedly severe normal tissue reactions. The ability to predict which patients might form this minority would be important. We have conducted a study to develop a rapid and reliable diagnostic test to predict excessive normal tissue toxicity (NTT) in radiotherapy patients. A flow cytometric immunocytochemical assay was used to measure DNA damage in peripheral blood lymphocytes (PBL) from cancer patients exposed to 2‐Gy gamma radiation. DNA damage and repair was measured by induction of cellular γ‐H2AX in unirradiated and exposed cells at specific time points following exposure. In 12 cancer patients that experienced severe atypical NTT following radiotherapy, there was a failure to repair DNA double‐strand breaks (DSB) as measured by γ‐H2AX induction and persistence. In ten cancer patients that experienced little or no NTT and in seven normal (noncancer controls), efficient repair of DNA DSB was observed in the γ‐H2AX assay. We conclude that a flow cytometric assay based on γ‐H2AX induction in PBL of radiotherapy patients may represent a robust, rapid and reliable biomarker to predict NTT during radiotherapy. Further research is required with a larger patient cohort to validate this important study.
Endothelin‐1 stimulates motility of head and neck squamous carcinoma cells by promoting stromal–epithelial interactions
Authors: Hinsley Emma E. , Hunt Stuart , Hunter Keith D. , Whawell Simon A. , Lambert Daniel W. 
Published: February 2011

AbstractThe invasion and migration of cancer cells is increasingly recognised to be influenced by factors derived from adjacent tumour‐associated stroma. The contextual signals regulating stromal–tumour interactions, however, remain poorly understood. Here, we identify a role for endothelin‐1 (ET‐1), a mitogenic peptide elevated in a number of malignancies, in promoting pro‐metastatic cross‐talk between head and neck cancer cells and adjacent fibroblasts. We demonstrate that treatment of oral fibroblasts with ET‐1 activates ADAM17‐mediated release of epidermal growth factor receptor (EGFR) ligands, triggering EGFR signalling and increased motility in neighbouring head and neck cancer cells. ET‐1–mediated paracrine transactivation of EGFR also increased cyclo‐oxygenase‐2 levels in the cancer cells, providing a molecular insight into the mechanisms by which the elevated levels of ET‐1 observed in head and neck cancers may contribute to disease progression.
Monocytes enhance cell proliferation and LMP1 expression of nasal natural killer/T‐cell lymphoma cells by cell contact‐dependent interaction through membrane‐bound IL‐15
Authors: Ishii Hideyuki , Takahara Miki , Nagato Toshihiro , Kis Loránd L. , Nagy Noémi , Kishibe Kan , Harabuchi Yasuaki , Klein Eva 
Published: February 2011

AbstractNasal natural killer (NK)/T‐cell lymphoma (NNKTL) is an Epstein‐Barr virus (EBV)‐related malignancy with poor prognosis and has distinct histological features characterized by angiocentric and polymorphous lymphoreticular infiltrates including inflammatory cells such as granulocytes, monocytes, macrophages and lymphocytes. Here, we show that the monocytes enhance proliferation as well as LMP1 expression of NNKTL cells by cell contact‐dependent interaction through membrane‐bound interleukin (IL)‐15. We used two EBV‐positive NK‐cell lines, SNK6 and KAI3, which originated from two patients—SNK6 from a patient with NNKTL and KAI3 from a patient with a severe mosquito allergy. We cocultured the cell lines with granulocytes or monocytes and examined whether proliferation, survival and LMP1 expression of the cells changed. Although cocultured granulocytes did not affect proliferation, survival or LMP1 expression of the cells, cocultured monocytes enhanced both proliferation and LMP1 expression in a dose‐dependent manner. These phenomena were not seen when monocytes were placed in a separate chamber. Moreover, the monocyte‐inducible proliferation and LMP1 expression were inhibited by treatment with an antibody against IL‐15. Furthermore, production of interferon‐gamma‐inducible protein (IP)‐10 were enhanced by coculture with monocytes and were inhibited by the antibody. Immunohistological studies confirmed that a number of infiltrating CD14‐positive monocytes contacted CD56‐positive lymphoma cells in all of 20 NNKTL tissues tested. These results suggest that monocytes enhance cell growth as well as LMP1 expression of NNKTL cells by cell contact‐dependent interaction through membrane‐bound IL‐15. In the microenvironment of NNKTL tissue, a positive feedback loop of interaction between lymphoma cells and monocytes may be present and contribute to lymphoma progression.
Tumor suppressor dual‐specificity phosphatase 6 (DUSP6) impairs cell invasion and epithelial‐mesenchymal transition (EMT)‐associated phenotype
Authors: Wong Victor Chun Lam , Chen Han , Ko Josephine Mun Yee , Chan Kwok Wah , Chan Yuen Piu , Law Simon , Chua Daniel , Kwong Dora Lai‐Wan , Lung Hong Lok , Srivastava Gopesh , Tang Johnny Cheuk On , Tsao Sai Wah , Zabarovsky Eugene R. , Stanbridge Eric J. , Lung Maria Li 
Published: February 2011

AbstractSuppressive effects of DUSP6 in tumorigenesis and EMT‐associated properties were observed. Dual‐specificity phosphatase (DUSP6) is a MAP kinase phosphatase (MKP) negatively regulating the activity of ERK, one of the major molecular switches in the MAPK signaling cascade propagating the signaling responses during malignancies. The impact of DUSP6 in EMT and its contribution to tumor dissemination has not yet been characterized. Due to differences in tumor microenvironments affecting cell signaling during cancer progression, DUSP6 may play varying roles in tumor development. We sought to examine the potential role of DUSP6‐mediated tumorigenesis and EMT‐associated properties in two aerodigestive tract cancers, namely, esophageal squamous cell carcinoma (ESCC) and nasopharyngeal carcinoma (NPC). Significant loss of DUSP6 was observed in 100% of 11 ESCC cell lines and 71% of seven NPC cell lines. DUSP6 expression was down‐regulated in 40% of 30 ESCC tumor tissues and 75% of 20 NPC tumor tissues compared to their respective normal counterparts. Suppressive effects of DUSP6 in tumor formation and cancer cell mobility are seen in in vivo tumorigenicity assay and in vitro colony formation, three‐dimensional Matrigel culture, cell migration and invasion chamber tests. Notably, overexpression of DUSP6 impairs EMT‐associated properties. Furthermore, tissue microarray analysis reveals a clinical association of DUSP6 expression with better patient survival. Taken together, our study provides a novel insight into understanding the functional impact of DUSP6 in tumorigenesis and metastasis of ESCC and NPC.
Parenteral is more efficient than mucosal immunization to induce regression of human papillomavirus‐associated genital tumors
Authors: Decrausaz Loane , Domingos‐Pereira Sonia , Duc Mélanie , Bobst Martine , Romero Pedro , Schiller John T. , Jichlinski Patrice , Nardelli‐Haefliger Denise 
Published: February 2011

AbstractCervical cancer is a public health concern as it represents the second cause of cancer death in women worldwide. High‐risk human papillomaviruses (HPV) are the etiologic agents, and HPV E6 and/or E7 oncogene‐specific therapeutic vaccines are under development to treat HPV‐related lesions in women. Whether the use of mucosal routes of immunization may be preferable for inducing cell‐mediated immune responses able to eradicate genital tumors is still debated because of the uniqueness of the female genital mucosa (GM) and the limited experimentation. Here, we compared the protective activity resulting from immunization of mice via intranasal (i.n.), intravaginal (IVAG) or subcutaneous (s.c.) routes with an adjuvanted HPV type 16 E7 polypeptide vaccine. Our data show that s.c. and i.n. immunizations elicited similar frequencies and avidity of TetE7+CD8+ and E7‐specific Interferon‐gamma‐secreting cells in the GM, whereas slightly lower immune responses were induced by IVAG immunization. In a novel orthotopic murine model, both s.c. and i.n. immunizations allowed for complete long‐term protection against genital E7‐expressing tumor challenge. However, only s.c. immunization induced complete regression of already established genital tumors. This suggests that the higher E7‐specific systemic response observed after s.c. immunization may contribute to the regression of growing genital tumors, whereas local immune responses may be sufficient to impede genital challenges. Thus, our data show that for an efficiently adjuvanted protein‐based vaccine, parenteral vaccination route is superior to mucosal vaccination route for inducing regression of established genital tumors in a murine model of HPV‐associated genital cancer.
A feedback loop between BEX2 and ErbB2 mediated by c‐Jun signaling in breast cancer
Authors: Naderi Ali , Liu Ji , Francis Glenn D. 
Published: February 2011

AbstractBEX2 is a member of brain expressed X‐linked gene family that is differentially expressed in primary breast tumors. We have previously demonstrated that BEX2 expression protects breast cancer cells against mitochondrial apoptosis and G1 cell cycle arrest. In addition, we have shown that BEX2 is a c‐Jun target gene and, in turn, regulates the phosphorylation of c‐Jun in breast cancer cells. In our study, we investigated BEX2 protein expression in a tissue microarray cohort of 225 breast tissue samples with known clinical, pathological and biomarker information. We observed that BEX2 protein was overexpressed in ∼50% of malignant breast tumors compared to only 7% of benign breast samples. Notably, BEX2 positive tumors identified a subset of breast cancers with the overexpression of ErbB2 and phosphorylated c‐Jun proteins. Furthermore, using in vitro models, we demonstrated that the mechanism of this association is a functional feedback loop involving ErbB2, c‐Jun and BEX2 in breast cancer cells. In this feedback loop, ErbB2 overexpression results in an induction of c‐Jun and BEX2 expression. Importantly, ErbB2 induction of BEX2 expression was abrogated by a dominant‐negative mutant of c‐Jun, suggesting that this effect was mediated through the regulation of c‐Jun signaling. In turn, the overexpression of BEX2 led to an increase in both c‐Jun–mediated induction of ErbB2 and c‐Jun binding to the ErbB2 promoter in MCF‐7 cells. Our study suggests that BEX2 protein is overexpressed in approximately half of breast cancers and has a positive feedback loop with ErbB2 mediated by c‐Jun signaling in breast cancer cells.
Nanoscale Digital Devices Based on the Photoelectrochemical Photocurrent Switching Effect: Preparation, Properties and Applications
Authors: Gawęda Sylwia , Kowalik Remigiusz , Kwolek Przemysław , Macyk Wojciech , Mech Justyna , Oszajca Marek , Podborska Agnieszka , Szaciłowski Konrad 
Published: February 2011

AbstractNew materials and new phenomena which can be used for information processing always inspire great enthusiasm. On the other hand, silicon is still the main workhorse of modern electronics. Production of bulk quantities of ultrapure silicon is relatively cheap and the processing technologies are extremely sophisticated. Introduction of new materials and phenomena, on the other hand, requires an enormous amount of hard experimental and theoretical work. The photoelectrochemical photocurrent switching effect (PEPS) is one of the processes that, in principle, can evolve into new information processing technology. This review presents the effect itself, along with preparation of appropriate semiconducting materials, physical principles of semiconductor–molecule interactions, and finally some prototypical constructions of logic devices based on the PEPS effect.
Biologically Relevant Molecular Finite Automata
Authors: Shoshani Sivan , Ratner Tamar , Piran Ron , Keinan Ehud 
Published: February 2011

AbstractBio‐Molecular Computing (BMC) has been rapidly evolving as an independent field at the interface between computer science, mathematics, chemistry, and biology. Over the years, numerous architectures of autonomous molecular computing devices have been developed in the lab on the basis of opportunities offered by molecular biology techniques. This account focuses mainly on the realization of programmable DNA‐based finite‐state automata that can compute autonomously upon mixing all their components in solution.The main advantage of autonomous BMC devices over electronic computers arises from their ability to interact directly with biological systems and even with living organisms without any interface. Indeed, it has been demonstrated that appropriately designed computing machines can produce output signals in the form of a specific biological function via direct interaction with living cells. Additional topics are briefly included to point at interesting opportunities in the field and to describe some of the potential applications and extension of the basic concepts. These include logic evaluators and logic gates that operate in cells, applications in developmental biology, as well as chemical encoding and processing of alphanumeric information.
Fiscal activism and the cost of debt financing
Authors: Dewachter Hans , Toffano Priscilla 
Published: February 2011

ABSTRACTIn this paper, we estimate the impact of changes in fiscal policy regime on the yield curve. In particular, we differentiate between yield curve responses under active and passive fiscal policy regimes (according to the terminology of Leeper (1991)). Analyzing US data in the period 1965–2010, we find a statistically significant impact of fiscal policy only for the active policy regime. A one‐percentage point shock in the primary deficit leads typically to a contemporaneous increase in long‐term yields of about 10 basis points, and even stronger cumulative effects. No significant impact of deficits on yields is found in the passive fiscal policy regime. Copyright © 2011 John Wiley & Sons, Ltd.
Improving irrigation water operation in the lower reaches of the Amu Darya River – current status and suggestions
Authors: Awan Usman Khalid , Ibrakhimov Mirzakhayot , Tischbein Bernhard , Kamalov Pulat , Martius Christopher , Lamers John P.A. 
Published: February 2011

AbstractIrrigated agriculture is widespread in the Central Asian drylands and important for food security of the region. However irrigation practices based on rules made for cotton production on large units do not provide adequate guidance for the now widespread small farms that produce cotton wheat and rice. Excessive unsustainable water use is the consequence. Land and water resource management practices were analysed in 2006 for the irrigated area (approx. 1885 ha) of a water users' association (WUA) as a case study. The Shomakhulum WUA is situated in the Khorezm region Uzbekistan in the Aral Sea Basin. The designed water allowance of 0.40 l s−1 ha−1 was 46% higher than the 0.21 l s−1 ha−1 required in 2006. A ponding experiment conducted at two locations under typically shallow groundwater conditions showed that actual seepage losses in the major distributing canal (Pakhtakiyar) in the WUA were about 2% at one site and negative at the other. This does not support the present blanket recommendation of an additional 29% of water to compensate for anticipated seepage losses. Considering the effects of shallow groundwater the seasonal leaching requirements were estimated at 200 mm versus the 400 mm based on the blanket local recommendations for a 14 ha cotton field. However the actually applied water amounted to 670 mm which exceeds the calculated requirements by 235% and the local recommendation by 68%. The findings showed (i) excessive irrigation water supply and in turn high wastage owing to an underestimation of the potential shallow groundwater contribution (ii) overestimation of conveyance losses and (iii) excessive leaching due to outdated knowledge on leaching requirements when compared to standards. We suggest that the outdated water allowance the inaccurate estimation of the conveyance efficiency and excessive water applications during leaching cause a waste of precious fresh water and a rise in the shallow groundwater levels which consequently increases secondary soil salinity. The revision of irrigation and leaching norms combined with an improved knowledge on seepage dynamics under shallow groundwater levels is needed before any further recommendations can be made to the farmers in order to reach the objective of sustainable agriculture in the area. Copyright © 2011 John Wiley & Sons Ltd.
Evaluation of modified DRAINMOD in predicting groundwater table fluctuations and yield of canola in paddy fields under snowy conditions (case study: Rasht Iran)
Authors: Hassanpour B. , Parsinejad M. , Yazdani M.R. , Dalivand F. Salahshour , Kossari H. 
Published: February 2011

AbstractThe computer simulation hydrologic model DRAINMOD and modified DRAINMOD (Luo et al. 2000) for cold condition was used to predict the performance of surface drainage and yield of canola as post‐rice cultivation during the wet growing season of 2004–2005 in Rasht Iran.Performance of surface drainage system treatments with 2 m spacing and 15 cm drain depth as compared with plots having no drainage (4 × 10 m2) were used to evaluate the models. Evaluation of predicted daily groundwater table depths as compared with measured values shows that the root mean square error (RMSE) was about 10.2 and 9.9 cm for DRAINMOD versus 11.0 and 11.5 for modified DRAINMOD in 2 m drain spacing and no drainage treatment respectively. Original DRAINMOD and modified DRAINMOD predictions for groundwater table depth was on average about 4 and 7% less than measured values for the surface drainage treatment and 22 and 14% greater for the no drainage treatment whereas the standard error of original DRAINMOD was 1.4 and 1.51 (cm) respectively. The average absolute deviations were 8.67 and 9.22 (cm). However by using the modified DRAINMOD these values were decreased to 1.34 1.3 8.05 and 8.19 cm respectively.Comparisons show that modifications introduced in DRAINMOD for snowy conditions improved the capability of the model to predict groundwater table fluctuations. Copyright © 2011 John Wiley & Sons Ltd.