bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrophilic S‐Trifluoromethylation of Cysteine Side Chains in α‐ and β‐Peptides: Isolation of Trifluoro‐methylated Sandostatin® (Octreotide) Derivatives
Authors: Capone Stefania , Kieltsch Iris , Flögel Oliver , Lelais Gerald , Togni Antonio , Seebach Dieter 
Published: November 2008

AbstractThe new electrophilic trifluoromethylating 1‐(trifluoromethyl)‐benziodoxole reagents A and B (Scheme 1) have been used to selectively attach CF3 groups to the S‐atom of cysteine side chains of α‐ and β‐peptides (up to 13‐residues‐long; products 7–14). Other functional groups in the substrates (amino, amido, carbamate, carboxylate, hydroxy, phenyl) are not attacked by these soft reagents. Depending on the conditions, the indole ring of a Trp residue may also be trifluoromethylated (in the 2‐position). The products are purified by chromatography, and identified by 1H‐, 13C‐, and 19F‐NMR spectroscopy, by CD spectroscopy, and by high‐resolution mass spectrometry. The CF3 groups, thus introduced, may be replaced by H (Na/NH3), an overall Cys/Ala conversion. The importance of trifluoromethylations in medicinal chemistry and possible applications of the method (spin‐labelling, imaging, PET) are discussed.
Further New Bis‐cembranoids from the Hainan Soft Coral Sarcophyton tortuosum
Authors: Jia Rui , Guo Yue‐Wei , Mollo Ernesto , Gavagnin Margherita , Cimino Guido 
Published: November 2008

AbstractTwo new bis‐cembranoids, ximaolides F (1) and G (2), were isolated from the Hainan soft coral Sarcophyton tortuosum. The structures and relative configurations of the two new compounds were elucidated by the combination of spectroscopic methods, chemical conversion of ximaolide F (1) into ximaolide G (2), and comparison with related model compounds.
Clintoniosides A – C, New Polyhydroxylated Spirostanol Glycosides from the Rhizomes of Clintonia udensis
Authors: Mimaki Yoshihiro , Watanabe Kazuki 
Published: November 2008

AbstractPhytochemical analyses were carried out on the rhizomes of Clintonia udensis (Liliaceae) with particular attention paid to the steroidal glycoside constituents, resulting in the isolation of three new polyhydroxylated spirostanol glycosides, named clintonioside A (1), B (2), and C (3). On the basis of their spectroscopic data, including 2D‐NMR spectroscopy, in combination with acetylation and hydrolytic cleavage, the structures of 1–3 were determined to be (1β,3β,23S,24S,25R)‐1,23,24‐trihydroxyspirost‐5‐en‐3‐yl O‐β‐D‐glucopyranosyl‐(1→4)‐O‐[α‐L‐rhamnopyranosyl‐(1→2)]‐β‐D‐glucopyranoside (1), (1β,3β,23S,24S)‐3,21,23,24‐tetrahydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (2), and (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(6‐deoxy‐β‐D‐gulopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (3).
A New Alkaloid from Lycopodium japonicumThunb.
Authors: Sun Yun , Yan Jian , Meng Hao , He Chun‐Lin , Yi Ping , Qiao Ying , Qiu Ming‐Hua 
Published: November 2008

AbstractA new alkaloid, miyoshianine C (1), was isolated from the whole plants of Lycopodium japonicum Thunb., together with the known four compounds α‐obscurine (2), lycodoline (3), miyoshianine A (4), and lucidioline (5). Their structures were elucidated on the basis of in‐depth spectroscopic analysis.
Eupatozansins A – C, Sesquiterpene Lactones from Eupatorium chinense var. tozanense
Authors: Liaw Chia‐Ching , Kuo Yao‐Haur , Hwang Tsong‐Long , Shen Ya‐Ching 
Published: November 2008

AbstractPhytochemical investigation of Eupatorium chinense var. tozanense has resulted in the isolation of three new germacranolides, designated as eupatozansins A–C (1–3), along with five known compounds, (5S,6R,7R,8R)‐8‐angeloyloxy‐2‐oxoguaia‐1(10),3,11(13)‐trien‐12,6‐olide (4), costunolide (5), leptocarpin (6), 2α‐hydroxyeupatolide 8‐O‐angelate (7), and quercetin (8). The structures of the new compounds were identified by 1D and 2D NMR experiments, as well as high‐resolution mass spectrometry. The in vitro cytotoxic activities of compounds 1–8 were evaluated.
New Sesquiterpenes from Edible Fungus Clavicorona pyxidata
Authors: Zheng Yong‐Biao , Lu Chun‐Hua , Zheng Zhong‐Hui , Lin Xin‐Jian , Su Wen‐Jin , Shen Yue‐Mao 
Published: November 2008

AbstractThree new sesquiterpenes, pyxidatol A–C (1–3, resp.), were obtained from the fermentation culture of Clavaria pyxidata, together with two known ones, tsugicoline E (4) and omphadiol (5). Their structures were elucidated through spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, HR‐ESI‐Q‐TOF mass spectrometry, chemical correlation, and X‐ray single‐crystal diffraction.
Agricultural pesticide use and pancreatic cancer risk in the Agricultural Health Study Cohort
Authors: Andreotti Gabriella , Freeman Laura E. Beane , Hou Lifang , Coble Joseph , Rusiecki Jennifer , Hoppin Jane A. , Silverman Debra T. , Alavanja Michael C.R. 
Published: November 2008

AbstractPancreatic cancer is a rapidly fatal disease that has been linked with pesticide use. Previous studies have reported excess risks of pancreatic cancer with organochlorines such as DDT, however, many other commonly used pesticides have not been examined. To further examine the potential associations between the use of a number of pesticides and pancreatic cancer, we conducted a case‐control analysis in the Agricultural Health Study, one of the largest prospective cohorts with over 89,000 participants including pesticide applicators and their spouses in Iowa and North Carolina. This analysis included 93 incident pancreatic cancer cases (64 applicators, 29 spouses) and 82,503 cancer‐free controls who completed an enrollment questionnaire providing detailed pesticide use, demographic and lifestyle information. Ever use of 24 pesticides and intensity‐weighted lifetime days [(lifetime exposure days) × (exposure intensity score)] of 13 pesticides was assessed. Risk estimates were calculated using unconditional logistic regression controlling for age, smoking, and diabetes. Among pesticide applicators, 2 herbicides (EPTC and pendimethalin) of the 13 pesticides examined for intensity‐weighted lifetime use showed a statistically significant exposure‐response association with pancreatic cancer. Applicators in the top half of lifetime pendimethalin use had a 3.0‐fold (95% CI 1.3–7.2, p‐trend = 0.01) risk compared with never users, and those in the top half of lifetime EPTC use had a 2.56‐fold (95% CI = 1.1–5.4, p‐trend = 0.01) risk compared with never users. Organochlorines were not associated with an excess risk of pancreatic cancer in this study. These findings suggest that herbicides, particularly pendimethalin and EPTC, may be associated with pancreatic cancer. © 2008 Wiley‐Liss, Inc.
Elevated circulating adiponectin and elevated insulin sensitivity in adiponectin transgenic mice are not associated with reduced susceptibility to colon carcinogenesis
Authors: Ealey Kafi N. , Archer Michael C. 
Published: November 2008

AbstractObesity, particularly visceral adiposity, is an established risk factor for colorectal cancer (CRC) and this is thought to result, at least in part, from insulin resistance and chronic hyperinsulinemia that may be mediated by adipokines. Serum levels of adiponectin, the most abundant protein secreted from adipocytes, are decreased in obesity and are inversely associated with insulin resistance and hyperinsulinemia. The objective of this study was to determine whether elevated circulating adiponectin plays a role in colon carcinogenesis using adiponectin transgenic (AdTg) mice that have 2–3‐fold elevated circulating adiponectin but similar body weights as wildtype (WT) littermates used as controls. Eight‐week old male and female AdTg and WT mice were treated with 4 weekly injections of the colon‐specific carcinogen azoxymethane (AOM). One week following the last dose of AOM, all mice were placed on a high‐fat diet and killed 24 weeks later, at 36 weeks of age, for the analysis of colon tumors. Glucose tolerance tests (GTT) were performed by injecting 2g/kg dextrose or 1.25–1.5 g/kg dextrose into all 12‐week and 32–35‐week‐old mice respectively, and measuring blood from the tail vein 15, 30, 60 and 120 min following glucose administration. There were no significant differences in colon tumor incidence, number or size between AdTg and WT mice of either sex. AdTg mice of both sexes displayed resistance to diet‐induced decreases in insulin sensitivity. Our results show that constitutively elevated levels of circulating adiponectin in AdTg mice do not confer protection against the development of colon tumors. © 2008 Wiley‐Liss, Inc.
Cigarette smoking and colorectal cancer incidence and mortality: Systematic review and meta‐analysis
Authors: Liang Peter S. , Chen Ting‐Yi , Giovannucci Edward 
Published: November 2008

AbstractThe association between cigarette smoking and colorectal cancer (CRC) has been controversial. To synthesize the available data, we conducted a comprehensive meta‐analysis of all prospective studies. A total of 36 studies were included in our meta‐analysis. We examined the association between smoking and CRC, colon cancer and rectal cancer in terms of incidence and mortality. Separate analyses were conducted for smoking status, daily cigarette consumption, duration, pack‐years and age of initiation. Relative to nonsmokers, current and former smokers had a significantly increased risk of CRC incidence and mortality, respectively. When CRC data were combined with colon/rectal cancer data, current smokers had a significantly increased risk of CRC incidence. All 4 dose–response variables examined—daily cigarette consumption (RR = 1.38 for an increase of 40 cigarettes/day), duration (RR = 1.20 for an increase of 40 years of duration), pack‐years (RR = 1.51 for an increase of 60 pack‐years) and age of initiation (RR = 0.96 for a delay of 10 years in smoking initiation)—were significantly associated with CRC incidence (all p‐values < 0.0001). The relationship between duration of smoking and rectal cancer incidence was also significant. Among the subset of studies that distinguished cancer by site, a higher risk was seen for rectal cancer than for colon cancer for all analyses. Among prospective studies, a consistent association exists between smoking and CRC. The association is stronger for rectal cancer than for colon cancer in the subset of studies that differentiated cancer by site. © 2008 Wiley‐Liss, Inc.
IGFBP‐2 overexpression reduces the appearance of dysplastic aberrant crypt foci and inhibits growth of adenomas in chemically induced colorectal carcinogenesis
Authors: Diehl Daniela , Hessel Esther , Oesterle Doris , Renner‐Müller Ingrid , Elmlinger Martin , Langhammer Martina , Göttlicher Martin , Wolf Eckhard , Lahm Harald , Hoeflich Andreas 
Published: November 2008

AbstractColon cancer patients frequently show increased levels of serum insulin‐like growth factor‐binding protein‐2 (IGFBP‐2), however, the pathogenetic relevance of this phenomenon for colorectal cancer is unclear. Therefore, we have used IGFBP‐2 transgenic animals which overexpress IGFBP‐2 systemically and locally in the intestine to study its role in chemically induced colorectal carcinogenesis. Mice received intraperitoneal injections of 1,2‐dimethylhydrazine (DMH) (40 mg/kg body weight) once a week for 6 weeks to selectively induce aberrant crypt foci (ACF) and tumors in the colon. While tumor incidence was comparable in transgenic and control mice, the volume of adenomas in IGFBP‐2 transgenic mice was reduced more than 2‐fold. Furthermore, serum IGFBP‐2 levels negatively correlated with tumor volume in the IGFBP‐2 transgenic group. Histological examination showed that IGFBP‐2 transgenic mice developed significantly less dysplastic ACF with a high potential to progress to advanced stages. The reduced tumor volume in IGFBP‐2 transgenic animals was due to significantly reduced proliferative capacity, evidenced by a lower proportion of cells positive for Ki67. Our results demonstrate for the first time in an experimental model that IGFBP‐2 overabundance prior to the onset and during colorectal carcinogenesis reduces tumor growth by inhibition of cell proliferation. © 2008 Wiley‐Liss, Inc.
Nonparametric identification and estimation of a class of common value auction models
Authors: Février Philippe 
Published: November 2008

AbstractStructural econometric studies on auctions have mainly focused on the independent private value paradigm. In this paper, we are interested in the ‘opposite’ case known as the pure common value model. More precisely, we restrict our attention to a class of common value models defined by three functions: the density of the true value of the auctioned good, a unique function that appears in the definition of the conditional densities of the signals, and the function that defines the support of the conditional densities. We establish that these common value models are nonparametrically identified without any further restrictions. We then propose a one‐step nonparametric estimation method and prove the uniform consistency of our estimators. We apply our method on simulated data and show that the technique we propose is adequate to recover the distribution functions of interest. Copyright © 2008 John Wiley & Sons, Ltd.
The role of large‐scale eddies in the occurrence of winter precipitation deficits in Portugal
Authors: Santos J. A. , Andrade C. , Corte‐Real J. , Leite S. 
Published: November 2008

AbstractThe severest winter precipitation deficits in Portugal result from an enhancement in the stationary wave pattern of the atmospheric large‐scale circulation over the Northern Hemisphere, which implies a strengthening of the axially asymmetric eddies, mainly over the North Atlantic and adjacent continental areas. This enhancement leads to a strong warm‐core ridge westward of Iberia, with a nearly equivalent barotropic structure, and a clear separation between the subtropical and polar‐front jet. These atmospheric conditions are clearly unfavourable to the establishment of rain‐generating mechanisms over Portugal, leading to a lack of precipitation and to extremely dry conditions with a high potential to trigger drought episodes. Conversely, the atmospheric flow during extremely wet winters contrasts highly with the above‐described conditions by presenting a significantly weakened North Atlantic ridge and a relatively unclear separation between the two westerly jets. A diagnosis of the main forcing dynamical mechanisms that generate and maintain the anomalous flow is carried out in two ways: by analyzing the Eliassen–Palm fluxes, zonally averaged over a North Atlantic window, and by calculating the third and sixth components of the empirical forcing functions. The former approach enables a quantification of the contributions made by the transient and stationary‐eddy transports of enthalpy and momentum to the establishment of the contrasting dynamical structures. The latter approach explores the role of local transient transports of enthalpy and angular momentum in forcing large‐scale asymmetries. Copyright © 2008 Royal Meteorological Society
Surface‐enhanced Raman scattering on colloid gels originated from low molecular weight gelator
Authors: Miljanić Snežana , Frkanec Leo , Biljan Tomislav , Meić Zlatko , Žinić Mladen 
Published: November 2008

AbstractSurface‐enhanced Raman scattering (SERS) on silver and gold colloid gels formed by a low molecular weight organic gelator, bis‐(S‐phenylalanine) oxalyl amide, was obtained. Strong Raman signals dominate in the SERS spectra of hydrogels containing silver nanoparticles prepared by citrate and borohydride reduction methods, whereas broad bands of low intensity are detected in the spectra of gold colloid gels. Resemblance between Raman spectrum of the crystalline substance and the SERS spectra of the silver nanoparticle–hydrogel composites implies the electromagnetic nature of the signal enhancement. A change in Raman intensity of the benzene and amide II bands caused by an increase in temperature and concentration indicates that the gelling molecules are strongly attached through the benzene moieties to the metal nanoparticles while participating in gel formation by intermolecular hydrogen bonding between the adjacent oxalyl amide groups. Transmission electron microscopy reveals a dense gel structure in the close vicinity of the enhancing metal particles for both silver colloid gels. Copyright © 2008 John Wiley & Sons, Ltd.
Carotenoids: Actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans
Authors: Maiani Giuseppe , Periago Castón María Jesús , Catasta Giovina , Toti Elisabetta , Cambrodón Isabel Goñi , Bysted Anette , Granado‐Lorencio Fernando , Olmedilla‐Alonso Begoña , Knuthsen Pia , Valoti Massimo , Böhm Volker , Mayer‐Miebach Esther , Behsnilian Diana , Schlemmer Ulrich 
Published: November 2008

AbstractCarotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re‐examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: β‐carotene, β‐cryptoxanthin, α‐carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.
Women's mammography experience and its impact on screening adherence
Authors: Tang Tricia S. , Patterson Stephanie K. , Roubidoux Marilyn A. , Duan Linping 
Published: November 2008

AbstractObjectives: Although rates for first‐time and recent mammography screening have increased for women in the US in the past decade, rates for repeat mammography remain low. This study aimed to conduct an analysis of women's mammography experience, to examine the rates of repeat mammography and to identify the significant predictors of repeat mammography within 12 and 18 months of the index mammogram.Methods: Participants were 397 women obtaining a screening mammogram (i.e. index) at three university‐affiliated radiology clinics. Following the index mammogram, women completed the measures assessing demographic background, health history, breast cancer knowledge, risk, and screening history, and aspects of the mammography experience. Eighteen months following the index mammogram, 296 women were contacted via telephone to assess repeat mammography behavior.Results: Factor analysis of a mammography experience survey yielded four major components including satisfaction with clinic services, physical experience, psychological experience, and communication with clinic staff. Twelve‐month and 18‐month repeat mammography rates were 37 and 68%, respectively. Logistic regression models found lifetime number of mammograms to predict repeat mammography at 12 and 18 months. In addition, the number of clinical breast exams obtained in the past 5 years predicted repeat mammography at 12 months, while having scheduled a mammography appointment predicted repeat mammography at 18 months.Conclusions: Based on these findings, strategies to increase mammography adherence include implementing a formal reminder system that prompts patients (e.g. postcard, automated telephone call) to schedule an annual mammogram or training clinic staff to automatically schedule an annual mammogram at the time of the current screening appointment. Copyright © 2008 John Wiley & Sons, Ltd.
Characterisation and cytomodulatory properties of peptides from Mozzarella di Bufala Campana cheese whey
Authors: De Simone Carmela , Picariello Gianluca , Mamone Gianfranco , Stiuso Paola , Dicitore Alessandra , Vanacore Daniela , Chianese Lina , Addeo Francesco , Ferranti Pasquale 
Published: November 2008

AbstractBioactive peptides are present in a latent state, encrypted within the amino acid sequence of milk proteins, requiring enzymatic proteolysis for their release. They can be produced by gastrointestinal digestion or food processing, thus they can be present in fermented milks, cheese and also in the by‐products of dairy industry such as waste whey. The spectrum of biological activity covered by milk‐derived peptides is extremely wide, including antibacterial, immunostimulating, antihypertensive, antithrombotic and opioid actions. However, the characterisation of milk‐derived peptides with classical analytical methodologies is severely challenged by the complexity of the milk protein fraction and by the wide dynamic range of relative peptide abundance in both dairy products and by‐products. Here we report the characterisation of the peptide fraction released in the whey during the different production stages of Mozzarella di Bufala Campana cheese. The peptide extracts were separated by RP HPLC and analysed by MS in order to identify the peptides produced and to trace the pathway of formation of potential bioactive peptides. The antioxidant properties and the modulatory effect on the cell cycle exerted by the peptide extracts were also studied in CaCo2 cell line. We found that a significant antiproliferative effect on CaCo2 was exerted by Mozzarella di Bufala waste whey peptides. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Lattice dynamics of chalcopyrite semiconductors LiAlTe2, LiGaTe2 and LiInTe2
Authors: Kosobutsky A. V. , Basalaev Yu. M. , Poplavnoi A. S. 
Published: November 2008

AbstractWithin density functional perturbation theory using norm‐conserving pseudopotentials and a plane‐wave basis set calculations of phonon dispersion relations and densities of states of LiAlTe2, LiGaTe2 and LiInTe2 compounds being crystallized into the tetragonal chalcopyrite structure have been performed. Theoretical values of phonon mode frequencies in LiGaTe2 and LiInTe2 are in good agreement with the experimental data available for these crystals obtained by the methods of Raman and infrared spectroscopies. The similarity of the physical and chemical properties of the crystals concerned manifests itself in the similarity of their phonon spectra that are especially close to each other in low‐ and high‐frequency ranges. Phonon modes of the upper phonon band are predominantly caused by the lithium sublattice vibrations and have an upper bound of 350–370 cm–1. In a mid‐frequency range a significant downshift of the vibrational frequencies is observed on going from LiAlTe2 to LiGaTe2 and LiInTe2 that is a consequence of the third group cation mass reduction. From calculated electron density maps it follows that Li‐containing chalcopyrites are characterized by a less pronounced bond between the first group cation and anion as compared with the Cu‐ and Ag‐based analogs due to the absence of pd‐hybridization. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combinatorial growth of Mgx Zn1–xO epilayers by chemical vapor deposition
Authors: Lautenschlaeger Stefan , Sann Joachim , Klar Peter J. , Piechotka M. , Meyer Bruno K. 
Published: November 2008

AbstractIt was our aim to explore the growth of Mgx Zn1–x O epilayers on ZnO substrates using CVD at substrate temperatures around 650 °C which is considerably lower than necessary for the MOCVD growth which requires substrate temperatures above 900 °C. Metallic precursors (Zn, Mg) were used together with NO2 as oxygen precursor. The Mg content was determined from the shift of longitudinal optical phonon line as a function of the Mg composition. The properties of the films were investigated by low temperature photoluminescence. Epitaxial Mgx Zn1–x O films with fixed Mg compositions required an individual adjustment of the Mg reservoir temperature. We, therefore, explored the possibility of a combinatorial growth i.e. achieving a Mg gradient within one sample. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)