bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of constitutively activated phosphoinositide 3‐kinase/AKT pathway enhances antitumor activity of chemotherapeutic agents in breast cancer susceptibility gene 1‐defective breast cancer cells
Authors: Yi Yong Weon , Kang Hyo Jin , Kim Hee Jeong , Hwang Jae Seok , Wang Antai , Bae Insoo 
Published: April 2012

AbstractLoss or decrease of wild type BRCA1 function, by either mutation or reduced expression, has a role in hereditary and sporadic human breast and ovarian cancers. We report here that the PI3K/AKT pathway is constitutively active in BRCA1‐defective human breast cancer cells. Levels of phospho‐AKT are sustained even after serum starvation in breast cancer cells carrying deleterious BRCA1 mutations. Knockdown of BRCA1 in MCF7 cells increases the amount of phospho‐AKT and sensitizes cells to small molecule protein kinase inhibitors (PKIs) targeting the PI3K/AKT pathway. Restoration of wild type BRCA1 inhibits the activated PI3K/AKT pathway and de‐sensitizes cells to PKIs targeting this pathway in BRCA1 mutant breast cancer cells, regardless of PTEN mutations. In addition, clinical PI3K/mTOR inhibitors, PI‐103, and BEZ235, showed anti‐proliferative effects on BRCA1 mutant breast cancer cell lines and synergism in combination with chemotherapeutic drugs, cisplatin, doxorubicin, topotecan, and gemcitabine. BEZ235 synergizes with the anti‐proliferative effects of gemcitabine by enhancing caspase‐3/7 activity. Our results suggest that the PI3K/AKT pathway can be an important signaling pathway for the survival of BRCA1‐defective breast cancer cells and pharmacological inhibition of this pathway is a plausible treatment for a subset of breast cancers. © 2012 Wiley Periodicals, Inc.
Deorphanization of Malonyl CoA:ACP Transacylase Drug Target in Plasmodium falciparum (PfFabD) Using Bacterial Antagonists: A ‘Piggyback’ Approach for Antimalarial Drug Discovery
Authors: Sreshty M. Asha Latha , Surolia Avadhesha , Sastry G. Narahari , Murty U. Suryanarayana 
Published: April 2012

AbstractQuest for new drug targets in Plasmodium sp. has underscored malonyl CoA:ACP transacylase (PfFabD) of fatty acid biosynthetic pathway in apicoplast. In this study, a “piggyback” approach was employed for the receptor deorphanization using inhibitors of bacterial FabD enzymes. Due to the lack of crystal structure, theoretical model was constructed using the structural details of homologous enzymes. Sequence and structure analysis has localized the presence of two conserved pentapeptide motifs: GQGXG and GXSXG and five key invariant residues viz., Gln109, Ser193, Arg218, His305 and Gln354 characteristic of FabD enzyme. Active site mapping of PfFabD using substrate molecules has disclosed the spatial arrangement of key residues in the cavity. As structurally similar molecules exhibit similar biological activities, signature pharmacophore fingerprints of FabD antagonists were generated using 0D‐3D descriptors for molecular similarity‐based cluster analysis and to correlate with their binding profiles. It was observed that antagonists showing good geometrical fitness score were grouped in cluster‐1, whereas those exhibiting high binding affinities in cluster‐2. This study proves important to shed light on the active site environment to reveal the hotspot for binding with higher affinity and to narrow down the virtual screening process by searching for close neighbors of the active compounds.
Multiple Kernel Learning for Drug Discovery
Authors: Pilkington Nicholas C. V. , Trotter Matthew W. B. , Holden Sean B. 
Published: April 2012

AbstractThe support vector machine (SVM) methodology has become a popular and well‐used component of present chemometric analysis. We assess a relatively recent development of the algorithm, multiple kernel learning (MKL), on published structure‐property relationship (SPR) data. The MKL algorithm learns a weighting across multiple kernel‐based representations of the data during supervised classifier creation and, thereby, may be used to describe the influence of distinct groups of structural descriptors upon a single structure–property classifier without explicitly omitting any of them. We observe a statistically significant performance improvement over a conventional, single kernel SVM on all three SPR data sets analysed. Furthermore, MKL output is observed to provide useful information regarding the relative influence of five distinct descriptor subsets present in each data set.
Generative Topographic Mapping (GTM): Universal Tool for Data Visualization, Structure‐Activity Modeling and Dataset Comparison
Authors: Kireeva N. , Baskin I. I. , Gaspar H. A. , Horvath D. , Marcou G. , Varnek A. 
Published: April 2012

AbstractHere, the utility of Generative Topographic Maps (GTM) for data visualization, structure‐activity modeling and database comparison is evaluated, on hand of subsets of the Database of Useful Decoys (DUD). Unlike other popular dimensionality reduction approaches like Principal Component Analysis, Sammon Mapping or Self‐Organizing Maps, the great advantage of GTMs is providing data probability distribution functions (PDF), both in the high‐dimensional space defined by molecular descriptors and in 2D latent space. PDFs for the molecules of different activity classes were successfully used to build classification models in the framework of the Bayesian approach. Because PDFs are represented by a mixture of Gaussian functions, the Bhattacharyya kernel has been proposed as a measure of the overlap of datasets, which leads to an elegant method of global comparison of chemical libraries.
Reliability and validity of the overactive bladder symptom score in spanish (OABSS‐S)
Authors: Weinberg Aaron C. , Brandeis Gary H. , Bruyere John , Tsui Johnson F. , Weiss Jeffrey P. , Rutman Matthew P. , Blaivas Jerry G. 
Published: April 2012

AbstractPurposeTo validate the Spanish translation of the Overactive Bladder Symptom Score (OABSS) questionnaire.Materials and MethodsThe OABSS was translated into Spanish (OABSS‐S) and back translated. The OABSS‐S was self‐administered to subjects, following internal IRB and ISPOR Good Practices guidelines. Spanish speaking patients >18 years of age were recruited from primary care clinics. Content validity was achieved by having the first 25 subjects complete the questionnaire in privacy; afterwards they were interviewed and the clarity of each question was discussed with the patient. All subjects recruited, including the first 25, were divided into two groups by the presence of OAB as determined by a previously validated intake question. Subjects completed the OABSS‐S in privacy on two occasions within 10 days. Patients were excluded if their symptoms changed between the first and second administration of the questionnaire. Internal consistency was determined with Cronbach's alpha. Test–retest was determined by Spearman's rho. Discriminant validity was assessed between each group using one‐way ANOVA and the Tukey post hoc test.ResultsOne hundred and seventeen of 128 enrolled subjects completed this study (mean age 55; SD 18). Of 117, 74 (63%) were women 29 with OAB and 45 without OAB. There were 43 men (37%), 18 with OAB and 25 without OAB. A high level of consistency was observed among the seven items answered at visit 1 and 2, with a Cronbach's raw alpha statistic of 0.92. No differences in OABSS‐S with age or gender were noted. However, subgroup analysis showed patients in the OAB group were significantly older and post‐test analysis showed they had higher scores both for each individual question as well as overall symptom severity scores. Spearman's rank order correlation coefficients showed that there was significant difference between the seven items of the OABSS‐S; a strong association (Spearman's rho) was also observed between the total seven‐item score at visits 1 and 2 for the total score of all subjects r = 0.84, with OAB: r = 0.81, and without OAB: r = 0.83. Comparison of average total scores obtained for all patients at visits 1 and 2 was not significant (10.47 ± 6.53 vs. 11.02 ± 0.66). Discriminant validity testing revealed that there were significant differences in the responses between all diagnostic groups at visits 1 and 2: with OAB versus without OAB; total versus with OAB; total versus without OAB.ConclusionThe Spanish version of the OABSS is valid and reliable and will allow health care providers to easily and quickly assess a Spanish‐speaking patient's symptoms. Neurourol. Urodynam. 31:664–668, 2012. © 2012 Wiley Periodicals, Inc.
Modification of poly(vinyl alcohol) films by the addition of magnesium chloride hexahydrate
Authors: Jiang Xiancai , Zhang Xiaofei , Ye Dezhan , Zhang Xi , Dai Hua 
Published: April 2012

AbstractPoly(vinyl alcohol) (PVA) films modified with Magnesium chloride hexahydrate (MgCl2·6H2O) were prepared by casting method. The prepared films were characterized by X‐ray diffraction measurements (XRD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and mechanical testing. It was found that the presence of MgCl2·6H2O had considerable effects on the crystallinity, thermal, and mechanical properties of PVA films. The crystallization of PVA film was interrupted and the degree of crystallinity of PVA film decreased with the addition of MgCl2·6H2O. The glass transition temperature of PVA film decreased with the addition of MgCl2·6H2O. After modifying with MgCl2·6H2O, PVA film became soft, with lower tensile strength and higher elongation at break. The presence of MgCl2·6H2O could significantly increase the moisture content of PVA films and this may be the cause of the plasticizing. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Central small‐angle diffuse scattering from fibers is made of two components
Authors: Wang Wenjie , Murthy N. Sanjeeva , Grubb David T. 
Published: April 2012

AbstractSmall‐angle X‐ray and neutron scattering from materials with fibrous texture generally includes a central diffuse scattering that is either diamond‐shaped or shaped like a two‐bladed propeller. The central scattering from fibers of polyacrylonitrile, nylon, and poly(ethylene terephthalate) and in particular the changes seen during deformation and heating have been examined. The result is that all types of central scattering from fibers are best described as having two distinct components, where these components are an extended equatorial streak and an inner nearly isotropic scattering. They arise respectively from objects that do and do not become aligned or elongated during fiber production. Examples of objects that do not become aligned are small spherical voids and solid particles. Objects that do become aligned include internal phase boundaries, and the surfaces of the fibers themselves. The equatorial streak arises from an assembly of such elongated objects preferentially oriented along the fiber axis. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Light to work transduction and shape memory in glassy, photoresponsive macromolecular systems: Trends and opportunities
Authors: White Timothy J. 
Published: April 2012

AbstractLight can wirelessly direct functional responses in photoresponsive polymeric materials and composites. The intensity, phase, and polarization of light can be spatially modulated into complex patterns with holography (intensity or polarization) or masking (intensity or phase). Deriving from these foundational properties of light, photoresponsive macromolecular systems exhibit exceeding potential to yield rapid and highly engineered macroscopic as well as spatially selectable mechanically adaptive responses useful as soft actuators or topographical surfaces in aerospace, automotive, and biomedical applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Estimating Ambient Vapor Pressures of Low Volatility Explosives by Rising‐Temperature Thermogravimetry
Authors: Brady Joseph E. , Smith James L. , Hart Casuarina E. , Oxley Jimmie 
Published: April 2012

AbstractVapor pressure is a fundamental physical characteristic of chemicals. Some solids have very low vapor pressures. Nevertheless numerous chemical detection instruments aim to detect vapors. Herein we address issues with explosive detection and use thermogravimetric analysis (TGA) to estimate vapor pressures. Benzoic acid, whose vapor pressure is well characterized, was used to calculate instrumental parameters related to sublimation rate. Once calibrated, the rate of mass loss from TGA measurements was used to obtain vapor pressures of the 12 explosives at elevated temperature: explosive salts – guanidine nitrate (GN); urea nitrate (UN); ammonium nitrate (AN); as well as mono‐molecular explosives – hexanitrostilbene (HNS); cyclotetramethylene‐tetranitramine (HMX), 4,10‐dinitro‐2,6,8,12‐tetraoxa‐4,10‐diaza‐tetracyclododecane (TEX), cyclotrimethylenetrinitramine (RDX), pentaerythritol tetranitrate (PETN), 3‐nitro‐1,2,4‐triazol‐5‐one (NTO), 1,3,3‐trinitroazeditine (TNAZ), triacetone triperoxide (TATP), and diacetone diperoxide (DADP). Ambient temperature vapor pressures were estimated by extrapolation of Clausius‐Clapeyron plots (i.e. ln p vs. 1/T). With this information potential detection limits can be assessed.
Salts of Tetrazolone – Synthesis and Properties of Insensitive Energetic Materials
Authors: Fischer Dennis , Klapötke Thomas M. , Stierstorfer Jörg 
Published: April 2012

AbstractTetrazolone (5‐oxotetrazole, 1) is formed by diazotization of 5‐aminotetrazole in the presence of CuSO4. Nitrogen‐rich salts such as guanidinium (2), 1‐aminoguanidinium (3), 1,3‐diamino‐guanidinium (4), 1,3,5‐triamino‐guanidinium (5), ammonium (6), hydrazinium (7) and the hydroxylammonium (8) salts of tetrazolone were prepared by facile deprotonation or metathesis reactions. All compounds were characterized by single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis and DSC measurements. The heats of formation of 2–8 were calculated using the atomization method based on CBS‐4M enthalpies. With these values and the experimental (X‐ray) densities several detonation parameters such as the detonation pressure, velocity, energy and temperature were computed using the EXPLO5 code (V.5.04). In addition, the sensitivities towards impact, friction and electrical discharge were tested using the BAM drop hammer and friction tester as well as a small scale electrical discharge device.
Chemoaffinity capture of pre‐targeted prostate cancer cells with magnetic beads
Authors: Wu Lisa Y. , Liu Tiancheng , Hopkins Mark R. , Davis William C. , Berkman Clifford E. 
Published: April 2012

AbstractBACKROUNDProstate circulating tumor cells (PCTCs) in circulation are shed from either a primary tumor or metastases, which are directly responsible for most prostate cancer deaths. Quantifying exfoliated PCTCs may serve as an indicator for the clinical management of prostate cancer, isolating and removing of PCTCs could potentially reduce prostate cancer metastasis, and culturing and characterizing captured PCTCs could facilitate the development of personalized treatment options. Prostate‐specific membrane antigen (PSMA) is an established biomarker for prostate cancer being strongly expressed on prostate tumor cells associated with high‐grade primary, androgen independent, and metastatic tumors.METHODSSuspensions of PSMA+ (LNCaP) cells were pre‐targeted with the irreversible PSMA inhibitor biotin‐PEG12‐CTT‐54 to serve as a bait to capture PSMA+ cells using streptavidin‐coated magnetic beads. Decreasing numbers of LNCaP cells were spiked into blood to determine the cell captured efficiency, recovery and viability.RESULTSHigh selectivity, recovery, and viability were achieved for the capture of PSMA+ cells in both model experiments with mixtures of LNCaP cells and WBCs as well as blood samples spiked with LNCaP cells. As low as 10 cells were captured from 1 ml of blood with nearly 90% viability. More importantly, captured cells could be subsequently propagated in vitro.CONCLUSIONSThis methodology for the detection, isolation, and culture of PCTCs from peripheral blood can serve as an effective tool for the detection of metastatic prostate cancer, treatment monitoring, and the development of personalized therapy based on the responsiveness of PCTCs to chemotherapeutic strategies. Prostate 72:1532–1541, 2012. © 2012 Wiley Periodicals, Inc.
Excitation effects and luminescence stability in porous SiO2:C layers
Authors: Vasin Andriy , Rusavsky Andriy , Nazarov Alexei , Lysenko Vladimir , Rudko Galyna , Piryatinski Yurii , Blonsky Ivan , Salonen Jarno , Makila Ermei , Starik Sergii 
Published: April 2012

AbstractWhite‐light emitting porous SiO2:C layers on silicon wafers have been fabricated by oxidation of carbonized porous silicon. The study was focused mainly on the identification of the mechanism of light emission and photo‐induced degradation. The effect of carbonization temperature and exposure to intense ultraviolet irradiation on the photoluminescence (PL) properties was studied by steady state and time‐resolved PL measurements. Two types of photo‐induced degradation phenomena were observed: reversible and irreversible. The irreversible degradation is suggested to be associated with photo‐induced chemical interaction of light emitting material with atmospheric oxygen. It is demonstrated that irreversible degradation can be reduced by encapsulation of the light‐emitting material. The structural configuration of light‐emitting centers and mechanism of reversible degradation are discussed.
Improved photoluminescence of red‐emitting NaCaPO4:Eu3+ phosphor by charge compensation
Authors: Chen Li , Hui Zhang Zhan , Tong Chun , Fu Cheng De , Liang Huang Zhi 
Published: April 2012

AbstractIn this paper, we report the preparation of a red‐emitting NaCaPO4:Eu3+ phosphor by the solid‐state method at 900 °C, also the effects of Eu3+ concentration on its luminescent properties were investigated. To achieve charge compensation, additional Na+ acting as a charge compensator was incorporated into the phosphor. Under near‐ultraviolet (UV) excitation, the luminescent properties as a function of additional Na+ concentration were systematically studied with a fixed optimal Eu3+ concentration. It was found that charge‐compensated phosphors showed greatly enhanced red emission at 619 nm, compared with the phosphor without charge compensation. Na1.3Ca0.4PO4:0.3Eu3+ was deduced to be the best composition and its luminescent intensity was stronger than that of commercial red‐emitting phosphors for white light‐emitting diode application.magnified imageThe emission spectra of as‐prepared NaCa0.7PO4:0.3Eu3+ (a), Na1.3Ca0.4PO4:0.3Eu3+ (b), and commercial Y2O2S:Eu3+ (c) phosphors excited by 395 nm.
Investigation of the stability of boron‐doped zinc oxide films grown by low‐pressure chemical vapor deposition
Authors: Zhu H. , Feng Y. , Zhang L. , Lai B. , He T. , Liu D. , Wang Y. , Yin J. , Ma Y. , Huang Y. , Jia H. , Mai Y. 
Published: April 2012

AbstractThe stability of transparent conductive oxide (TCO) films of silicon thin‐film solar cells is important to the device performance. As an important TCO material, the boron‐doped zinc oxide (ZnO:B) films are grown by a low‐pressure chemical vapor deposition (LPCVD) technique. The stability of ZnO:B films with different doping levels is systematically investigated through a post‐thermal treatment at temperatures of 300 and 250 °C for different durations. In addition, the variations of optical and electrical properties of ZnO:B films after a damp‐heat treatment are studied as well. It is found that the stability of the ZnO:B films with a high doping level is better compared to lowly doped ZnO:B films. Moreover, the total transmission (TT) in the near‐infrared (NIR) wavelength range increases with increasing temperature and duration of the thermal treatment. With the increasing damp‐heat exposure duration, the TT in the NIR wavelength range slightly increases while the sheet resistance increases up to three orders of magnitude. Such observations imply a higher degradation of carrier mobility than carrier density. Further, it is found that ZnO:B films, especially those with low doping levels, show an obvious degradation in electrical properties when they are stored in normal room ambient. All these discoveries will be a great help to the practical mass production of solar modules.
Band offsets of atomic layer deposited Al2O3 and HfO2 on Si measured by linear and nonlinear internal photoemission
Authors: Lei M. , Yum J. H. , Banerjee S. K. , Bersuker G. , Downer M. C. 
Published: April 2012

AbstractWe present measurements of band alignment of atomic layer deposited high‐k dielectrics on Si(100) using linear internal photoemission (IPE), detected by measuring photocurrent from a biased MOS capacitor, and internal multi‐photon photoemission (IMPE), detected by optical second‐harmonic generation (SHG). In IPE, Band offsets are extracted from either the threshold of quantum yield; in IMPE, they are determined by detecting discrete increments in multi‐photon order. IPE and IMPE yielded identical conduction band (CB) offsets (2.0 eV) for as‐deposited Si/Al2O3 structures with 10 and 3 nm oxides, respectively, in excellent agreement with previous measurements of annealed structures. Band offset measurements for Si/HfO2, on the other hand, show a strong (0.3 eV) upshift of the oxide valence band (VB) maximum, and an equal decrease of the oxide band gap upon post‐deposition annealing (PDA) at 600 °C, while the CB offset remains unchanged. We attribute the shift of the VB edge to thermally driven oxygen diffusion away from the Si/HfO2 interface.
Fractal dimension determined through optical and scanning electron microscopy on FeCrAl alloy after polishing, erosion, and oxidizing processes
Authors: Guzmán‐Castañeda J. I. , García‐Bórquez A. , Arizabalo‐Salas R. D. 
Published: April 2012

AbstractOptical and scanning electron microscopy (OM and SEM) are techniques that are normally used for 2D‐analysis of surface features. By fractal dimension analysis of the gray‐scale OM and SEM images, it is possible to get quantitative topographical measurements. In this work, three different surface topographies (polished, eroded, and oxidized) were analyzed on FeCrAl alloy by OM and SEM. Clear surface topographical changes can be qualitatively observed. In order to quantify such changes, two steps were followed: (i) a gray‐scale digitalization from each image was used to reproduce topographical features on the analyzed surface, and (ii) from this information, the fractal dimension (D) was determined using fractal3e software. The fractal dimension determined in this form follows coherently the topographical changes produced on the FeCrAl alloy after polishing, erosion, and oxidizing processes. The variations of fractal dimension values against the temperature of the oxidizing processes reflect well the oxide growth changes. Moreover, a minimum D‐value is registered at 750 °C, which corresponds to the δ–θ alumina phase transition temperature as determined by differential thermal analysis (DTA) on the same alloy.
Mechanical properties of L12type Al3X (X = Mg, Sc, Zr) from first‐principles study
Authors: Fu Lin , Ke Jiang‐Ling , Zhang Quan , Tang Bi‐Yu , Peng Li‐Ming , Ding Wen‐Jiang 
Published: April 2012

AbstractThe mechanical properties of L12type Al3X (X = Mg, Sc, Zr) have been investigated by first‐principles calculations. The calculated elastic properties showed that Al3Sc was the stiffest and intrinsically brittle, while Al3Mg was the softest and exhibited ductility tendency. The obtained stress–strain curves demonstrated that both of the ideal tensile and shear strengths of Al3Zr were the strongest, followed by Al3Sc and Al3Mg, and Al3Zr was also the most ductile among three phases, which disagreed with the prediction from the calculated elastic properties, indicating that the mechanical properties should be measured from the complete stress–strain relations at both small and large strains. The electronic density of states (DOS) especially the variations of the charge density during the strain loading were investigated to unveil the intrinsic mechanism for the mechanical properties of L12type Al3X (X = Mg, Sc, Zr) phases.