bluuebunny/crossref_metadata_2025_split huggingface dataset:
17α‐estradiol inhibits LAPC‐4 prostatic tumor cell proliferation in cell cultures and tumor growth in xenograft animals
Authors: Qiao Yaming , Zhang Zhi‐Kai , Cai Li‐Qun , Tan Chen , Imperato‐McGinley Julianne L. , Zhu Yuan‐Shan 
Published: September 2007

AbstractBACKGROUNDBlockade of androgen activity is a major effective therapy for advanced prostate cancer. Estrogen analogs have been used for prostate cancer therapy for years presumably by inhibiting testosterone biosyntheses, but with considerable adverse events due to their classic estrogenic activity. With the discovery of the estrogen receptor (ER) β and its presence in prostate tumor cells, evaluation of estrogen analogs with less classic estrogenic activity in prostate cancer therapy is emerging.METHODSThe effects of 17α‐estradiol (αE2), a stereo‐isomer of 17β‐estradiol (βE2), on dihydrotestosterone (DHT)‐induced cell growth and gene expressions were examined in androgen‐dependent LAPC‐4 prostatic tumor cells and in LAPC‐4 xenograft animals, and compared to those of βE2.RESULTSBoth αE2 and βE2 attenuated DHT induction of PSA gene expression, cell proliferation, and cell growth in cultured LAPC‐4 cells. The inhibition of cell proliferation was associated with a blockade of DHT‐induced cyclin A and cyclin D1 expression by αE2 and βE2. In LAPC‐4 xenograft mice, αE2 significantly inhibited tumor growth without altering the plasma testosterone level, while βE2 failed to inhibit tumor growth even though it significantly inhibited PSA gene expression.CONCLUSIONαE2 is an effective agent for inhibition of DHT‐induced PSA, cyclin A, cyclin D1 gene expression, and cell proliferation in LAPC‐4 cells, and tumor growth in LAPC‐4 xenograft mice. Prostate 67: 1719–1728, 2007. © 2007 Wiley‐Liss, Inc.
Association of IGF‐1 and IGFBP‐3 with lower urinary tract symptoms in the third national health and nutrition examination survey
Authors: Rohrmann Sabine , Giovannucci Edward , Smit Ellen , Platz Elizabeth A 
Published: September 2007

AbstractBACKGROUNDBenign growth of the prostate is thought to contribute to lower urinary tract symptoms (LUTS) in older men. It is, however, unclear which factors induce prostate growth in these men. We examined the association of insulin‐like growth factor (IGF)‐1 and its major binding protein IGFBP‐3 with LUTS in a representative US study.METHODSWe included men 60 years and older who participated in the morning session of the Third National Health and Examination Survey (NHANES III) between 1988 and 1994. Men were classified as cases (n = 91) if they reported at least three of four LUTS (nocturia, incomplete emptying, hesitancy, or weak stream) but had not had non‐cancer prostate surgery in the past. Controls were men without symptoms and surgery (n = 220). All results were weighted to account for sampling probability in NHANES III. IGF‐1 and IGFBP‐3 were measured by ELISA and IRMA, respectively.RESULTSAfter mutual adjustment, men in the highest tertile of serum IGF‐1 concentration had a non‐significantly higher odds of LUTS than men in the lowest tertile (odds ratio (OR) = 3.20; 95% confidence interval (CI) 0.89–11.4; p‐trend = 0.09]. A high concentration of IGFBP‐3 was inversely related to the odds of LUTS (OR = 0.25; 95% CI 0.08–0.81; p‐trend = 0.02).CONCLUSIONA high IGFBP‐3 level might affect LUTS by decreasing the bioavailability of IGF‐1 or independent of IGF‐1 by up‐regulating apoptosis, and, thus, limiting its growth promoting effects on the prostate. Prostate 67: 1693–1698, 2007. © 2007 Wiley‐Liss, Inc.
A coarse‐grained α‐carbon protein model with anisotropic hydrogen‐bonding
Authors: Yap Eng‐Hui , Fawzi Nicolas Lux , Head‐Gordon Teresa 
Published: September 2007

AbstractWe develop a sequence based α‐carbon model to incorporate a mean field estimate of the orientation dependence of the polypeptide chain that gives rise to specific hydrogen bond pairing to stabilize α‐helices and β‐sheets. We illustrate the success of the new protein model in capturing thermodynamic measures and folding mechanism of proteins L and G. Compared to our previous coarse‐grained model, the new model shows greater folding cooperativity and improvements in designability of protein sequences, as well as predicting correct trends for kinetic rates and mechanism for proteins L and G. We believe the model is broadly applicable to other protein folding and protein–protein co‐assembly processes, and does not require experimental input beyond the topology description of the native state. Even without tertiary topology information, it can also serve as a mid‐resolution protein model for more exhaustive conformational search strategies that can bridge back down to atomic descriptions of the polypeptide chain. Proteins 2008. © 2007 Wiley‐Liss, Inc.
A unique and differential effect of denaturants on cofactor mediated activation of Plasmodium falciparum β‐ketoacyl‐ACP reductase
Authors: Karmodiya Krishanpal , Surolia Namita 
Published: September 2007

AbstractThe urea and guanidinium chloride (GdmCl) induced unfolding of FabG, a β‐ketoacyl‐ACP reductase of Plasmodium falciparum, was examined in detail using intrinsic fluorescence of FabG, UV‐circular dichroism (CD), spectrophotometric enzyme activity measurements, glutaraldehyde cross‐linking, and size exclusion chromatography. The equilibrium unfolding of FabG by urea is a multistep process as compared with a two‐state process by GdmCl. FabG is fully unfolded at 6.0M urea and 4.0M GdmCl. Approximately 90% of the enzyme activity could be recovered on dialyzing the denaturants, showing that denaturation by both urea and GdmCl is reversible. We found two states in the reversible unfolding process of FabG in presence of NADPH; one is an activity‐enhanced state and the other, an inactive state in case of equilibrium unfolding with urea. On the contrary, in presence of NADPH, there is no stabilization of FabG in case of equilibrium unfolding with GdmCl. We hypothesize that the hydrogen‐bonding network may be reorganized by the denaturant in the activity‐enhanced state formed in presence of 1.0M urea, by interrupting the association between dimer–dimer interface and help in accommodating the larger substrate in the substrate binding tunnel thus, increasing the activity. Furthermore, binding of the active site organizer, NADPH leads to compaction of the FabG in presence of urea, as evident by acrylamide quenching. We have shown here for the first time, the detailed inactivation kinetics of FabG, which have not been evaluated in the past from any of the FabG family of enzymes from any of the other sources. These findings provide impetus for exploring the influences of ligands on the structure–activity relationship of Plasmodium β‐ketoacyl‐ACP reductase. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Molecular determinants of sarco/endoplasmic reticulum calcium ATPase inhibition by hydroquinone‐based compounds
Authors: Lape Michael , Elam Christopher , Versluis Maria , Kempton Robert , Paula Stefan 
Published: September 2007

AbstractThe ion transport activity of the sarco/endoplasmic reticulum calcium ATPase (SERCA) is specifically and potently inhibited by the small molecule 2,5‐di‐tert‐butylhydroquinone (BHQ). In this study, we investigated the relative importance of the nature and position of BHQ's four substituents for enzyme inhibition by employing a combination of experimental and computational techniques. The inhibitory potencies of 21 commercially available or synthesized BHQ derivatives were determined in ATPase activity assays, and 11 compounds were found to be active. Maximum inhibitory potency was observed in compounds with two para hydroxyl groups, whereas BHQ analogues with only one hydroxyl group were still active, albeit with a reduced potency. The results also demonstrated that two alkyl groups were an absolute requirement for activity, with the most potent compounds having 2,5‐substituents with four or five carbon atoms at each position. Using the program GOLD in conjunction with the ChemScore scoring function, the structures of the BHQ analogues were docked into the crystal structure of SERCA mimicking the enzyme's E2 conformation. Analysis of the docking results indicated that inhibitor binding to SERCA was primarily mediated by a hydrogen bond between a hydroxyl group and Asp‐59 and by hydrophobic interactions involving the bulky inhibitor alkyl groups. Attempts to dock BHQ into crystal structures corresponding to the E1 conformation of the enzyme failed, because the conformational changes accompanying the E2/E1 transition severely restricted the size of the binding site, suggesting that BHQ stabilizes the enzyme in its E2 form. The potential role of Glu309 in enzyme inhibition is discussed in the context of the computational results. The docking scores correlated reasonably well with the measured inhibitory potencies and allowed the distinction between active and inactive compounds, which is a key requirement for future virtual screening of large compound databases for novel SERCA inhibitors. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Modelling long‐term effects of IGRs on honey bee colonies
Authors: Thompson Helen M , Wilkins Selwyn , Battersby Alastair H , Waite Ruth J , Wilkinson David 
Published: September 2007

AbstractSystems have been developed to monitor the direct effects of insect growth regulator (IGR) pesticide exposure on honey bee development, but there has been little work on the longer‐term impact of exposure on the colony. A honey bee population model provided the opportunity to investigate the effects of short‐term mortality of brood and of sublethal changes in behaviour of the surviving adults on honey bee populations. The model showed that brood mortality alone has limited effect on colony size. There were two mechanisms that could have greater influence on productivity. Precocious foraging in affected adult bees, and hence early loss of brood‐rearing (nurse) capabilities, had a much larger effect than expected. Increasing mortality rates by 30% to simulate sublethal effects on lifespan, rather than reduced brood‐rearing capability, gave a significantly smaller effect. In order to simulate an effect with the ‘shortened lifespan’ mechanism as large as that with the ‘premature ageing’ mechanism, the mortality rate of affected adults had to be increased by 500%. A significant finding from the model is that application of IGRs in spring and early summer could have substantial effects on colony size and viability. Sublethal effects such as precocious foraging can have worse effects than massive brood mortality, as it severely reduces the ability to rear the next generation of nurse bees. © Crown copyright 2007. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Effects of annealing on the properties and structure of electrodeposited semiconducting Cu–O thin films
Authors: Wijesundera R. P. , Hidaka M. , Koga K. , Sakai M. , Siripala W. , Choi Jae‐Young , Sung Nark Eon 
Published: September 2007

AbstractThe structures and the electronic states in electrodeposited semiconductor Cu–O thin films have been investigated for each annealing temperature (TA) by X‐ray diffraction (XD) and X‐ray absorption spectroscopy (XAS) near the Cu K edge using synchrotron radiation. The thin films prepared as grown and annealed at TA ≤ 175 °C, 200 °C ≤ TA ≤ 300 °C, TA = 400 °C are characterized mainly by the pure Cu2O‐type structure, the pseudo‐Cu2O‐type having a superlattice structure, and two phases of Cu2O‐type and CuO‐type structures, respectively, while the film annealed at TA = 500 °C is single‐phase CuO‐type. The XAS spectra suggest that there is a structural phase transition occurring at about 400 °C, which induces a modulation of the local structure around Cu ions observed in the extended X‐ray absorption fine structure (EXAFS) and the occupational electronic band states of Cu‐4p localized just above the Fermi level, taken from X‐ray absorption near edge structure (XANES). The open‐circuit voltage suggests that the photosensitivity of the Cu–O thin films strongly depends on the annealing treatment and shows a crossover from an n‐type to a p‐type semiconductor. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nuclear fusion rate for ddμ muonic molecule
Authors: Gheisari R. , Avazpour A. 
Published: September 2007

AbstractA variational approach using a new wave function to ddμ muonic molecular ion is proposed. This approach requires four terms in the total three‐body wave function. The formation and fusion take place by the reason of the existence of the both Coulomb potential and nuclear absorption. The nuclear fusion rates and eigenvalues related to such levels below dμ(1s) + d threshold are calculated with a good accuracy and a short computation time. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Stable 2H isotope analysis of modern‐day human hair and nails can aid forensic human identification
Authors: Fraser Isla , Meier‐Augenstein Wolfram 
Published: September 2007

AbstractContinuous‐flow isotope ratio mass spectrometry (CF‐IRMS) was used to compare 2H isotopic composition at natural abundance level of human scalp hair and fingernail samples collected from subjects worldwide with interpolated δ2H precipitation values at corresponding locations. The results showed a strong correlation between δ2H values of meteoric water and hair (r2 = 0.86), while the corresponding correlation for nails was not as strong (r2 = 0.6). Offsets of −180‰ and −127‰ were observed when calculating solutions of the linear regression analyses for δ2H vs. δ18O correlation plots of hair and nail samples, respectively. Compared with the +10‰ offset of the global meteoric water line equation these findings suggested that δ18O data from hair and nail would be of limited diagnostic value. The results of this pilot study provide for the first time tentative correlations of 2H isotopic composition of human hair and nails with local water. Linear regression analyses for measured δ2H values of human hair and nails vs. water yielded δ2H(hair) = 0.49 × δ2H(water) − 35 and δ2H(nails) = 0.38 × δ2H(water) − 49, respectively. The results suggest that 2H isotopic analysis of hair and nail samples can be used to provide information regarding an individual's recent geographical life history and, hence, location. The benefit of this technique is to aid identification of victims of violent crime and mass disasters in circumstances where traditional methods such as DNA and fingerprinting cannot be brought to bear (or at least not immediately). Copyright © 2007 John Wiley & Sons, Ltd.
GasBench/isotope ratio mass spectrometry: a carbon isotope approach to detect exogenous CO2 in sparkling drinks
Authors: Cabañero Ana I. , San‐Hipólito Tamar , Rupérez Mercedes 
Published: September 2007

AbstractA new procedure for the determination of carbon dioxide (CO2) 13C/12C isotope ratios, using direct injection into a GasBench/isotope ratio mass spectrometry (GasBench/IRMS) system, has been developed to improve isotopic methods devoted to the study of the authenticity of sparkling drinks. Thirty‐nine commercial sparkling drink samples from various origins were analyzed. Values of δ13Ccava ranged from −20.30‰ to −23.63‰, when C3 sugar addition was performed for a second alcoholic fermentation. Values of δ13Cwater ranged from −5.59‰ to −6.87‰ in the case of naturally carbonated water or water fortified with gas from the spring, and δ13Cwater ranged from −29.36‰ to −42.09‰ when industrial CO2 was added. It has been demonstrated that the addition of C4 sugar to semi‐sparkling wine (aguja) and industrial CO2 addition to sparkling wine (cava) or water can be detected. The new procedure has advantages over existing methods in terms of analysis time and sample treatment. In addition, it is the first isotopic method developed that allows 13C/12C determination directly from a liquid sample without previous CO2 extraction. No significant isotopic fractionation was observed nor any influence by secondary compounds present in the liquid phase. Copyright © 2007 John Wiley & Sons, Ltd.
Simplifying sample handling for protein identification by peptide mass fingerprint using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Cordeiro Francisco M. , Carreira Ricardo J. , Rial‐Otero Raquel , Rivas M. Gabriela , Moura Isabel , Capelo Jose‐Luis 
Published: September 2007

AbstractAn ultrasonic bath, an ultrasonic probe and a sonoreactor were used to speed up the kinetics of the reactions involved in each step of the sample handling for in‐gel protein identification by peptide mass fingerprint, PMF, using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS). The following steps were successfully accelerated using ultrasonic energy: gel washing, protein reduction, and protein alkylation. As a result, a reduction comprising 80% to 90% of the total time involved in the classic approach was achieved. In addition the sample handling was also drastically simplified. The number of peptides identified and the protein sequence coverage obtained for the new procedure were comparable to those obtained with the traditional sample treatment for the following protein standards: glycogen phosphorylase b, BSA, ovalbumin, carbonic anhydrase, trypsin inhibitor and α‐lactalbumin. Finally, as a proof of the procedure, specific proteins were identified from complex protein mixtures obtained from three different sulphate‐reducing bacteria: Desulfovibrio desulfuricans G20, Desulfuvibrio gigas NCIB 9332, and Desulfuvibrio desulfuricans ATCC 27774. Copyright © 2007 John Wiley & Sons, Ltd.
Specific isolation of N‐terminal fragments from proteins and their high‐fidelity de novo sequencing
Authors: Yamaguchi Minoru , Obama Takashi , Kuyama Hiroki , Nakayama Daisuke , Ando Eiji , Okamura Taka‐aki , Ueyama Norikazu , Nakazawa Takashi , Norioka Shigemi , Nishimura Osamu , Tsunasawa Susumu 
Published: September 2007

AbstractA new method to determine N‐terminal amino acid sequences of multiple proteins at low pmol level by a parallel processing has been developed. The method contains the following five steps: (1) reduction, S‐alkylation and guanidination for targeted proteins; (2) coupling with sulfosucccimidyl‐2‐(biotinamido)ethyl‐1,3‐dithiopropionate(sulfo‐NHS‐SS‐biotin) to Nα‐amino groups of proteins; (3) digestion of the modified proteins by an appropriate protease; (4) specific isolation of N‐terminal fragments of proteins by affinity capture using the biotin‐avidin system; (5) de novo sequence analysis of peptides by MALDI‐TOF‐/MALDI‐TOF‐PSD mass spectrometry with effective utilization of the CAF (chemically assisted fragmentation) method.1 This method is also effective for N‐terminal sequencing of each protein in a mixture of several proteins, and for sequencing components of a multiprotein complex. It is expected to become an essential proteomics tool for identifying proteins, especially when used in combination with a C‐terminal sequencing method.2, 3 Copyright © 2007 John Wiley & Sons, Ltd.
The intriguing case of organic impurities contained in synthetic methanol: a mass spectrometry based investigation
Authors: Guella Graziano , Ascenzi Daniela , Franceschi Pietro , Tosi Paolo 
Published: September 2007

AbstractThe role of organic impurities in the methanol‐to‐olefin (MTO) industrial process catalyzed by zeolites is the subject of ongoing debate. We have found that methanol (HPLC and RPE grade) purchased from different chemical companies may contain organic impurities, whose ionization is the dominant process in the positive ion atmospheric pressure chemical ionization (APCI) spectrum of commercial CH3OH. Such impurities produce ions with elemental formulae CnH2n+1O+ (n = 4, 5, 6); likewise, ionization of tetradeuterated methanol (CD3OD) leads to the corresponding fully deuterated series CnD2n+1O+ (n = 4, 5, 6), an outcome which represents a clear evidence of their widespread diffusion. We suggest that their formation might be inherent to the chemical process whereby methanol is synthesized on an industrial scale. Mass spectrometry (MS) experiments, gas chromatography/mass spectrometry (GC/MS) analysis and nuclear magnetic resonance (NMR) measurements allowed us to establish that commercial methanol contains dimethyl acetals of simple alkyl ketones, such as propanone, butanone and pentanone. Ab initio calculations (DFT/B3LYP) proved useful to understanding the ionization mechanisms of such impurities. Copyright © 2007 John Wiley & Sons, Ltd.
Efficient IP‐multicast via Inmarsat BGAN, a 3GPP satellite network
Authors: Febvre Paul , Bouthors Xavier , Maalouf Simon , Bath David 
Published: September 2007

AbstractThis paper outlines a number of challenges associated with supporting IP‐multicast services efficiently across the Inmarsat Broadband Global Area Network (BGAN) 3GPP‐based satellite network operating over the Imarsat‐4 satellite constellation. The paper presents a network architecture that extends the 3GPP reference architecture to allow IP‐multicast to be delivered when the Core Network is in a 3GPP Release‐4 (non‐MBMS compliant) configuration.This paper further extends the service and system concepts defined in 3GPP MBMS to provide improved flexibility and accountability, and improved scalability and efficiency when operating with the Inmarsat‐4 BGAN TDM/TDMA air interface.This paper describes a number of radio resource management techniques that were deployed in a test system and the validation testing that was undertaken to support multimedia distribution and VoIP‐based netted communications applications. The tuning of application and system behaviour to achieve acceptable performance is described in outline. Copyright © 2007 John Wiley & Sons, Ltd.
Antenna diversity for DVB‐S2 mobile services in railway environments
Authors: Cioni S. , Corazza G. E. , Vanelli‐Coralli A. 
Published: September 2007

AbstractThis paper evaluates the applicability of the DVB‐S2 standard in railway environments, where the most peculiar impairment is the periodic deep fading caused by power‐supply arches distributed along the rail tracks. This effect induces a link loss every time the train antenna undergoes a power arch and cannot be counteracted with transmission power. Therefore, we propose and investigate the use of antenna diversity on the train. Simulation and semi‐analytical results show that second‐order diversity suffices to remove the packet error floor observed in the case of a single receiving antenna, thus enabling the application of DVB‐S2 to this harsh environment. Copyright © 2007 John Wiley & Sons, Ltd.
Interworking between MANET and satellite systems for emergency applications
Authors: Luglio Michele , Monti Cristiano , Roseti Cesare , Saitto Antonio , Segal Michael 
Published: September 2007

AbstractThis paper presents the main achievements of a project, focused on the design of an integrated system composed of a satellite segment and a MANET to provide telecommunication services in emergency scenarios, in terms of network design, focusing in particular on the development of the interface between the two systems and showing the results of field trials. Copyright © 2007 John Wiley & Sons, Ltd.
Environmental citizenship: towards sustainable development
Authors: Dobson Andrew 
Published: September 2007

AbstractIt is assumed that changes in the behaviour of individuals, institutions and organizations are a prerequisite for sustainable development. This article broaches the question of how best to bring about such change. A distinction is drawn between changes in behaviour and changes in attitudes, and it is argued that attendance to the latter will lead to more secure and long‐lasting changes in the former. Fiscal incentives, as a means of changing behaviour, are compared and contrasted with the ‘environmental citizenship’ route to attitude change, rooted in considerations of justice and injustice. Finally, the citizenship curriculum at high school level is considered as a way of promoting environmental or ecological citizenship. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.