bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural conformations and electronic interactions of the natural product, oroxylin: a vibrational spectroscopic study
Authors: Abraham Jose P. , Sajan D. , Mathew Joseph , Hubert Joe I. , George V. , Jayakumar V. S. 
Published: July 2008

AbstractThe oroxylin, 5,7‐dihydroxy 6‐methoxy flavone is a potent natural product extracted from ‘Vitex peduncularis’. Density functional theory (DFT) at B3LYP/6‐311G(d,p) level has been used to compute energies of different conformers of oroxylin to find out their stability, the optimized geometry of the most stable conformer and its vibrational spectrum. The conformer ORLN‐1 with torsion angles 0, 180, 180 and 0 degrees, respectively, for H13O12C6C5, H14O10C4C5, H13O12C6C5 and H14O10C4C5 is found to be most stable. The optimized geometry reveals that the dihedral angle φ between phenyl ring B and the chrome part of the molecule in − 19.21° is due to the repulsive force due to steric interaction between the ortho‐hydrogen atom H29 of the B ring and H18 of the ring C (H29·H18 = 2.198 Å). A vibrational analysis based on the near‐infrared Fourier transform(NIR‐FT) Raman, Fourier transform‐infrared (FT‐IR) and the computed spectrum reveals that the methoxy group is influenced by the oxygen lone pair‐aryl pz orbital by back donation. Hence the stretching and bending vibrational modes of the methoxy group possess the lowest wavenumber from the normal values of methyl group. The carbonyl stretching vibrations have been lowered due to conjugation and hydrogen bonding in the molecules. The intramolecular H‐bonding and nonbonded intramolecular interactions shift the band position of O10H14 and O12H13 stretching modes, which is justified by DFT results. Copyright © 2008 John Wiley & Sons, Ltd.
Vibrational spectroscopic studies and DFT calculations of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide
Authors: Ushakumari L. , Varghese Hema Tresa , Panicker C. Yohannan , Ertan Tugba , Yildiz Ilkay 
Published: July 2008

AbstractFourier transform infrared (FT‐IR) and FT‐Raman spectra of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red‐shift of the NH‐stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the CO‐stretching mode gives the charge transfer interaction through a π‐conjugated path. Copyright © 2008 John Wiley & Sons, Ltd.
Resonance Raman study of He+ ion implanted nanostructured ZnS
Authors: Kumar S. Saravana , Khadar M. Abdul , Nair K. G. M. , Dhara S. , Magudapathy P. 
Published: July 2008

AbstractZnS nanocrytsals of size ∼2.5 nm were prepared by chemical precipitation technique. Pressed pellets of nanostructured ZnS were implanted with He+ ions at doses of 5 × 1014, 1 × 1015 and 5 × 1015 ions/cm2. Raman spectra of both unimplanted and He+ ion implanted samples were recorded with ultraviolet (UV) excitation. LO, 2LO, 2TO, (LO + TA) and (2TO − TA) modes of ZnS were observed in the resonance Raman spectra of the unimplanted nanostructured ZnS samples. In addition, a surface mode was observed at 294 cm−1. With the implantation of He+ ions, the 2TO mode disappeared and 2LO mode became prominent and this observation was attributed to the decrease in band gap of ZnS nanocrytsals due to ion implantation. The exciton–LO phonon coupling strength was determined from the intensity ratio of 2LO to LO modes and it was observed that the exciton–LO phonon coupling strength increases with increase in implantation dose. In the present work, we report for the first time the observation of 2TO mode in the resonance Raman spectrum of nanostructured ZnS and also the modification of exciton–LO phonon coupling strength of semiconductor nanoparticles by ion implantation. Copyright © 2008 John Wiley & Sons, Ltd.
Pseudopolymorphic transitions of niclosamide monitored by Raman spectroscopy
Authors: Sardo Mariana , Amado Ana M. , Ribeiro‐Claro Paulo J. A. 
Published: July 2008

AbstractNiclosamide suffers pseudopolymorphic transformations when exposed to different ambient conditions, which can lead to changes in its bioavailability. In this study, the kinetics of the pseudopolymorphic transitions of niclosamide crystals are characterized. FT‐Raman spectroscopy is used to quantify the anhydrate and hydrate forms of niclosamide crystals, mostly because of its high sensitivity to the strong intermolecular interactions present in these systems. The samples are exposed to well‐characterized relative humidity (RH) conditions during different periods of time and both water diffusion and polymorphic changes are monitored from the corresponding changes observed in the vibrational spectra. Both hydration and dehydration were found to be single‐step processes, with a half‐life time of ca. 142 and 63 h, respectively, at 24 °C. Copyright © 2008 John Wiley & Sons, Ltd.
Selection of best candidates for multiorgan resection among patients with T4 gastric carcinoma
Authors: Oñate‐Ocaña Luis F. , Becker Mauricio , Carrillo José F. , Aiello‐Crocifoglio Vincenzo , Gallardo‐Rincón Dolores , Brom‐Valladares Rocío , Herrera‐Goepfert Roberto , Ochoa‐Carrillo Francisco , Beltrán‐Ortega Arturo 
Published: July 2008

AbstractBackground and ObjectiveIndications for gastrectomy in T4 gastric carcinoma (GC) remain controversial. Our aim was to define prognostic factors to select those patients with best chance to benefit from multiorgan resection.Materials and MethodsA cohort of patients with T4 GC treated in a 19‐year period. Surgical morbidity‐associated factors were identified by logistic regression analysis. Prognostic factors were defined by Kaplan–Meier and Cox methods.ResultsSeven hundred eighteen patients were included (gastrectomy performed in 169). Surgical morbidity and mortality were 39% and 10.7%, respectively. Surgical morbidity were associated to extent of gastrectomy, age, serum albumin, and lymphocyte count (P = 0.0001). Presence of metastasis (hazard ratio [HR], 1.68; 95% confidence interval [95% CI], 1.19–2.36), albumin <3 g/dl plus lymphocytes <1,000 cells/mm3 (HR, 2.9; 95% CI, 1.8–4.6), presence of ascites (HR, 2.1; 95% CI, 1.06–4.2), age ≥50 (HR, 1.37; 95% CI, 1.02–1.8), and unresectable disease (HR, 2.6; 95% CI, 1.7–4.1) defined poor survival (P = 0.00001).ConclusionPerforming a multiorgan resection must be balanced between chances for long‐term survival and surviving a potentially fatal operation. Absence of metastases, serum albumin levels >3 g/dl, and accomplishment of R0 resection select patients with high probability of benefit from multiorgan resection. J. Surg. Oncol. 2008;98:336–342. © 2008 Wiley‐Liss, Inc.
Linear and nonlinear stability thresholds for a diffusive model of pioneer and climax species interaction
Authors: Buonomo Bruno , Rionero Salvatore 
Published: July 2008

AbstractIn this paper a reaction–diffusion model describing two interacting pioneer and climax species is considered. The role of diffusivity and forcing (stocking or harvesting of the species) on the nonlinear stability of a coexistence equilibrium is analysed. The study is performed in the context of a new approach to nonlinear L2‐stability based on the analysis of stability of the zero solution of a suitable linear system of ordinary differential equations. Theorems concerning the effect of forcing and diffusivity on the dynamics are established and stability–instability thresholds for the system are obtained. An example to illustrate the practical use of the results is also provided. Copyright © 2008 John Wiley & Sons, Ltd.
Urinary excretion of strawberry anthocyanins is dose dependent for physiological oral doses of fresh fruit
Authors: Hollands Wendy , Brett Gary M. , Dainty Jack R. , Teucher Birgit , Kroon Paul A. 
Published: July 2008

AbstractThere is considerable interest in coloured fruits and berries as sources of biologically active anthocyanins. To examine the relationship between the oral dose and the amount excreted for anthocyanins from a food source across a physiological range of doses, volunteers were fed, in random order, four portions (100–400 g) of fresh strawberries as part of a standard breakfast. Urine was collected at 2 h intervals up to 8 h, and for the period 8–24 h. Fresh strawberries contained pelargonidin‐3‐glucoside as the major anthocyanin with smaller amounts of cyanidin‐3‐glucoside and pelargonidin‐3‐rutinoside. Anthocyanins were detected in the urine of all volunteers for all doses, predominantly as pelargonidin glucuronide and sulphate metabolites. There was a strong, linear relationship between oral dose and anthocyanin excretion (Pearson's product moment correlation coefficient = 0.692, p < 0.001, n = 40) which indicated that on an average, every additional unit of dose caused 0.0166 units of excretion. Within individuals, dose – excretion data fitted a linear regression model (median R2 = 0.93). We conclude that strawberry anthocyanins are partially bioavailable in humans with a linear relationship between oral dose and urinary excretion for doses up to 400 g fresh fruit.
Absorption of N‐phenylpropenoyl‐L‐amino acids in healthy humans by oral administration of cocoa (Theobroma cacao)
Authors: Stark Timo , Lang Roman , Keller Daniela , Hensel Andreas , Hofmann Thomas 
Published: July 2008

AbstractBesides flavan‐3‐ols, a family of N‐phenylpropenoyl‐L‐amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC‐MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N‐[4′‐hydroxy‐(E)‐cinnamoyl]‐L‐aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N‐[4′‐hydroxy‐(E)‐cinnamoyl]‐L‐glutamic acid (6) and N‐[4′‐hydroxy‐3′‐methoxy‐(E)‐cinnamoyl]‐L‐tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC‐MS/MS before and after β‐glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O‐glucuronides nor their O‐sulfates. In order to screen for caffeic acid O‐glucuronides as potential NPA metabolites, urine samples were screened by means of LC‐MS/MS for caffeic acid 3‐O‐β‐D‐glucuronide and 4‐O‐β‐D‐glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O‐methylation or reduction of the N‐phenylpropenoyl moiety in NPAs.
Fungal siderophores function as protective agents of LDL oxidation and are promising anti‐atherosclerotic metabolites in functional food
Authors: Pócsi István , Jeney Viktória , Kertai Pál , Pócsi Imre , Emri Tamás , Gyémánt Gyöngyi , Fésüs László , Balla József , Balla György 
Published: July 2008

AbstractIron‐mediated oxidation of low‐density lipoprotein has been implicated in the pathogenesis of vascular disorders such as atherosclerosis. The present investigations were performed to test whether hydrophobic fungal siderophores – hexadentate trihydroxamates desferricoprogen, desferrichrome, desferrirubin, and desferrichrysin – might suppress heme‐catalyzed LDL oxidation and the toxic effects of heme‐treated LDL on vascular endothelium. Indeed, two of these – desferricoprogen and desferrichrome – markedly increased the resistance of LDL to heme‐catalyzed oxidation. In similar dose–response fashion, these siderophores also inhibited the generation of LDL products cytotoxic to human vascular endothelium. When iron‐free fungal siderophores were added to LDL/heme oxidation reactions, the product failed to induce heme oxygenase‐1, a surrogate marker for the noncytocidal effects of oxidized LDL (not in the case of desferrichrysin). Desferricoprogen also hindered the iron‐mediated peroxidation of lipids from human atherosclerotic soft plaques in vitro, and was taken up in the gastrointestinal tract of rat. The absorbed siderophore was accumulated in the liver and was secreted in its iron‐complexed form in the feces and urine. The consumption of mold‐ripened food products such as aged cheeses and the introduction of functional foods and food additives rich in fungal iron chelators in diets may lower the risk of cardiovascular diseases.
Expression of microRNA processing machinery genes in rhesus monkey oocytes and embryos of different developmental potentials
Authors: Mtango Namdori R. , Potireddy Santhi , Latham Keith E. 
Published: July 2008

AbstractMicroRNAs (miRNAs) are a class of small RNAs that silence gene expression. In animal cells, miRNAs bind to the 3′ untranslated regions of specific mRNAs and inhibit their translation. The correct regulation of mRNA expression by miRNAs is believed to be important for oocyte maturation, early development and implantation. We examined the expression of 25 mRNAs involved in the microRNA processing pathway in a nonhuman primate oocyte and embryo model. We observed that mRNAs related to miRNA splicing are downregulated during oocyte maturation while those related to miRNA processing are upregulated, indicating that there may exist a temporal difference in their activities related to transcriptional activity in germinal vesicle stage oocytes. We also observed that the vast majority of mRNAs examined were insensitive to α‐amanitin at the 8–16 cell stage. The expression data did not reveal a major impact of embryo culture, and hormonal stimulation protocol affected only a small number of mRNAs, suggesting that the components of the pathway may be accumulated in the oocyte during oogenesis and resistant to exogenous insults. In comparison to published mouse array data, we observed species differences and similarities in the temporal expression patterns of some genes, suggesting that miRNA processing may be regulated differently. These data extend our understanding of the potential roles of miRNA during primate embryogenesis. Mol. Reprod. Dev. 76: 255–269, 2009. © 2008 Wiley‐Liss, Inc.
Network design for time‐constrained delivery
Authors: Chen Hui , Campbell Ann Melissa , Thomas Barrett W. 
Published: July 2008

AbstractTo meet customer demand, delivery companies are offering an increasing number of time‐definite services. In this article, we examine the strategic design of delivery networks which can efficiently provide these services. Because of the high cost of direct connections, we focus on tree‐structured networks. As it may not be possible to identify a tree‐structured network that satisfies all of the delivery guarantees, we allow these guarantees to be violated but seek to minimize the sum of the violations. We establish the complexity of the problem and exploit an empirically identified solution structure to create new neighborhoods which improve solution values over more general neighborhood structures. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Collaborative procurement among competing buyers
Authors: Keskinocak Pinar , Savaşaneril Seçil 
Published: July 2008

AbstractCollaborative procurement emerged as one of the many initiatives for achieving improved inter‐firm coordination and collaboration. In this article, we adopt a game‐theoretical approach to study the interaction between two firms who procure jointly, but produce independently and remain competitors in a product market characterized by price‐sensitive demand. We study the underlying economics behind collaborative procurement, examine the effects of collaboration on buyer and supplier profitability, and derive conditions under which collaboration is beneficial to each participant. We find that a necessary and sufficient condition for a buyer to collaborate is to increase its sales. We identify the conditions that lead equal size buyers (i.e., consortia consisting of only large buyers or only small buyers) versus different size buyers to collaborate. We also determine the conditions that make collaboration profitable for the supplier, and show that rather than selling a large quantity to a single buyer, the supplier prefers to sell to multiple buyers in smaller quantities. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Collection depots facility location problems in trees
Authors: Benkoczi Robert , Bhattacharya Binay , Tamir Arie 
Published: July 2008

AbstractWe consider a generalization of the median and center facility location problem called the collection depots facility location (CDFL) problem. We are given a set of client locations and a set of collection depots and we are required to find the placement for a certain number of facilities, so that the cost of dispatching a vehicle from a facility, to a client, to a collection depot, and back, is optimized for all clients. The CDFL center problem minimizes the cost of the most expensive vehicle tour among all clients, and the CDFL median problem minimizes the sum of the tour costs for all clients. We provide the first polynomial time algorithms to solve the 1 and k median problems in trees with time complexities O(n log n) and O(kn3), respectively, where n is the number of vertices in the tree. In contrast, a restricted version of the k‐median problem, where clients are given lists of allowed collection depots, is NP‐complete even for star graphs. We also give an optimal linear time algorithm to solve the discrete and continuous weighted 1‐center problem, improving on the O(n log n) result of Tamir and Halman [Discrete Optimization 2(2005), 168–184]. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
Conceptualizing and measuring illness self‐concept: A comparison with self‐esteem and optimism in predicting fibromyalgia adjustment
Authors: Morea Jessica M. , Friend Ronald , Bennett Robert M. 
Published: July 2008

AbstractIllness self‐concept (ISC), or the extent to which individuals are consumed by their illness, was theoretically described and evaluated with the Illness Self‐Concept Scale (ISCS), a new 23‐item scale, to predict adjustment in fibromyalgia. To establish convergent and discriminant validity, illness self‐concept was compared to self‐esteem and optimism in predicting health status, illness intrusiveness, depression, and life satisfaction. The ISCS demonstrated good reliability (α = .94; test–retest r = .80) and was a strong predictor of outcomes, even after controlling for optimism or self‐esteem. The ISCS predicted unique variance in health‐related outcomes; optimism and self‐esteem did not, providing construct validation. Illness self‐concept may play a significant role in coping with fibromyalgia and may prove useful in the evaluation of other chronic illnesses. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:563–575, 2008
Thiophene‐based ionic liquids: synthesis, physical properties, self‐assembly, and oxidative polymerization
Authors: Burns Christopher T. , Lee Sungwon , Seifert Sönke , Firestone Millicent A. 
Published: July 2008

AbstractPreparation and polymerization of methylimidazolium‐based ionic liquids (ILs) that incorporate a thiophene moiety at the terminus of a C10 alkyl chain are described. Both a bromide and nitrate salt of the amphiphilic thiophene IL self‐assembles in water (albeit the nitrate to a lesser extent), adopting columnar mesophases. Polarized optical microscopy and small‐angle X‐ray scattering (SAXS) studies show that at low water content the IL–water binary mixtures form liquid crystalline mesophases possessing significant short‐range ordering due to strong π interactions between adjacent thiophene moieties. At higher water content, the short‐range ordering is lost, but long‐range ordering persists up to ca. 45% (w/w) water. The chemical oxidative coupling of the nitrate monomer yields a highly water‐soluble polymer. Electrochemical studies show that the polymer possesses a high oxidation potential (1.95 V) and thus, is resistant to chemical doping. In dilute aqueous solution, electronic absorption spectroscopy and X‐ray scattering show the polymer adopts a random, coil‐like conformational state. Slight improvement in the polymer conformation can be achieved by exchange of the counter anion. Copyright © 2008 John Wiley & Sons, Ltd.
Myocardial function in patients with Shwachman–Diamond syndrome: Aspects to consider before stem cell transplantation
Authors: Toiviainen‐Salo Sanna , Pitkänen Olli , Holmström Miia , Koikkalainen Juha , Lötjönen Jyrki , Lauerma Kirsi , Taskinen Mervi , Savilahti Erkki , Smallhorn Jeffrey , Mäkitie Outi , Kivistö Sari 
Published: July 2008

AbstractBackgroundEarly studies have suggested increased risk of fatal cardiac complications in infants with Shwachman–Diamond syndrome (SDS), an inherited bone marrow failure syndrome. Patients undergoing stem cell transplantation (STC) have appeared susceptible to organ toxicity, including cardiac involvement.ProcedureThis study assessed anatomical and functional features of the heart in SDS. Eight patients (mean age 24.1 years, range 7–37 years, seven males) with SDS and confirmed SBDS mutations were prospectively assessed for cardiac anatomy, myocardial wall properties, and systolic and diastolic function. The study protocol included conventional echocardiography (n = 8) complemented by exercise Tissue‐Doppler echocardiography (n = 7), and by MRI (n = 6).ResultsNo abnormalities in cardiac anatomy or function were observed in baseline clinical assessment, EKG, or conventional echocardiographic and MRI measurements. Myocardial structure and left ventricular (LV) mass were normal. The maximum isovolumic acceleration (IVA) value during exercise in Tissue‐Doppler was significantly lower (P < 0.001), and the right ventricular (RV) ejection fraction (P = 0.02) and peak filling rate (PFR, P = 0.008) at rest in MRI were higher in patients.ConclusionsChildren and young adults with SDS and mutations in SBDS had normal cardiac anatomy and myocardial structure. Subtle RV diastolic function alterations at rest and depressed LV contractility during exercise were observed. Further studies are warranted to evaluate the clinical importance of these findings. Pediatr Blood Cancer 2008;51:461–467. © 2008 Wiley‐Liss, Inc.