bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pancytopenia with myelodysplasia due to copper deficiency
Authors: Angotti Lauren B. , Post Ginell R. , Robinson Nancy S. , Lewis Jocelyn A. , Hudspeth Michelle P. , Lazarchick John 
Published: July 2008

AbstractWe present a case of pancytopenia in a 9‐month‐old infant with total parenteral nutrition (TPN) dependence due to short bowel syndrome. Bone marrow examination revealed left‐shifted myeloid maturation, erythroid and myeloid dysplasia with normal iron stores. Serum copper level was 2 µm/dl (normal range 90–190 mcg/dl). After supplementation, copper levels normalized at 143 mcg/dl, and the macrocytic anemia, neutropenia, and thrombocytopenia resolved. Copper deficiency should be considered in the differential diagnosis of cytopenias and myelodsyplasia, particularly in the growing number of pediatric patients with TPN dependency or malabsorption. Pediatr Blood Cancer 2008;51:693–695. © 2008 Wiley‐Liss, Inc.
Clofarabine in refractory Langerhans cell histiocytosis
Authors: Rodriguez‐Galindo Carlos , Jeng Michael , Khuu Phuong , McCarville M. Beth , Jeha Sima 
Published: July 2008

AbstractPatients with multi‐system Langerhans cell histiocytosis (LCH) who progress on frontline therapy have a dismal outcome. Responses to cladribine have been reported in relapsed LCH, but there are no well defined salvage regimens for LCH is refractory to therapy. The next generation deoxyadenosine analog, clofarabine, has demonstrated activity in patients with leukemia that is refractory to salvage regimens, including other nucleotide congeners; however, no experience exist on the use of clofarabine in LCH. In this report we describe significant single agent activity of clofarabine in disseminated LCH refractory to salvage regimens, including cladribine. Pediatr Blood Cancer 2008;51:703–706. © 2008 Wiley‐Liss, Inc.
Late effects in survivors of tandem peripheral blood stem cell transplant for high‐risk neuroblastoma
Authors: Hobbie Wendy L. , Moshang Thomas , Carlson Claire A. , Goldmuntz Elizabeth , Sacks Nancy , Goldfarb Samuel B. , Grupp Stephan A. , Ginsberg Jill P. 
Published: July 2008

AbstractBackgroundIncreasing numbers of children with advanced neuroblastoma are achieving cure. We describe the clinical late effects specific to survivors of stage IV neuroblastoma all similarly treated using tandem autologous peripheral blood stem cell rescue with TBI.MethodThe medical records of 35 neuroblastoma patients treated at CHOP between 1997 and 2001 were examined. Eighteen of the 35 patients died of progressive disease, and 4 were lost to follow‐up. Thirteen patients continue to follow‐up in our Multidisciplinary Cancer Survivorship Clinic where they are evaluated and monitored by a consistent group of subspecialists that evaluate long‐term sequelae. Data on treatment exposures including TBI and treatment related sequelae identified by clinician assessment and/or diagnostic testing were collected.ResultsResults indicate late effects were present in all 13 subjects, 12 of whom suffered from multiple negative sequelae, including issues with growth hormone deficiency, dental problems, osteochondromas and hearing deficiencies, among others, most at higher rates than reported previously.ConclusionsThe findings in this small cohort indicate the need for future prospective studies of this intensive pediatric cancer treatment, and underscore the importance of medical intervention and long‐term monitoring of these at‐risk subjects to increase overall quality‐of‐life. Pediatr Blood Cancer 2008;51:679–683. © 2008 Wiley‐Liss, Inc.
New evidence for the molecular–chemical diversity of potato plant rhizodeposits obtained by pyrolysis–field Ionisation mass spectrometry
Authors: Schlichting André , Leinweber Peter 
Published: July 2008

AbstractIntroduction – Detailed descriptions of the molecular–chemical diversity in plant rhizodeposits are scarce. The vast majority of our knowledge is derived from a priori methods of analysis, such as GC‐MS and HPLC.Objective – To analyse the composition of rhizodeposits from the potato cultivar Solanum tuberosum L. cv. Albatros by pyrolysis –field ionisation mass spectrometry (Py–FIMS) and to explain differences in relation to plant growth stage and photoperiod.Methodology – Potato (Solanum tuberosum L.) plants were grown in non‐sterile, native soil under controlled environmental conditions (plant chamber). Rhizodeposit samples were collected by leaching during two different growth stages and after the physiological day‐ and night‐cycle. All leachate samples were investigated by Py–FIMS. Mass spectrometric data were evaluated by multivariate statistics.Results – Screening of the rhizodeposits by Py–FIMS revealed a broad range of m/z signals. Low‐molecular‐weight substances of m/z 15–56 (8.1–18.6%), alkylaromatics (12.0–15.9%), phenols and lignin monomers (8.8–13.1%) and carbohydrates (6.0–11.2%) comprised the largest proportions of total ion intensity (TII). Mass signals with significantly different abundance at the various sampling dates were assigned to compound classes of carbohydrates, phenols and lignin monomers, lignin dimers, lipids, N‐containing compounds, sterols, peptides and free fatty acids; these were supplemented by marker signals for N‐acetylmuramic acid from bacterial cell walls and signal molecules for the regulation of secondary pathways such as 4‐hydroxycinnamic acid and linolenic acid.Conclusion – Py–FIMS was well suited to detect the molecular‐chemical diversity of potato plant rhizodeposits and, compared with traditional a priori analytical methods, provided detailed evidence for significant differences in the composition of rhizodeposits depending on growth stage and diurnal period. Copyright © 2008 John Wiley & Sons, Ltd.
Assessment of different sample processing procedures applied to the determination of melatonin in plants
Authors: Arnao Marino B. , Hernández‐Ruiz Josefa 
Published: July 2008

AbstractIntroduction – Melatonin, an indoleamine well known in vertebrates and structurally related to other important substances such as tryptophan or indole‐3‐acetic acid, is also present in the plant kingdom although its specific function(s) remain to be established. The emerging field of melatonin studies in plants has progressed very slowly, mainly due to the problems associated with melatonin quantification in plants.Objective – Two commonly used procedures for plant samples are compared. The analytical characteristics of both procedures are quantitatively presented using different solvents and small amounts of fresh biological material, and the respective recovery rates and quantitative limits are presented. Some improvements are suggested.Methodology – Two different sample extraction procedures were compared: a direct‐sample extraction (DSE) and a homogenised‐ sample extraction (HSE). Melatonin was then determined in the respective plant samples by HPLC with fluorescence detection.Results – Using the DSE procedure, more than 94% melatonin was recovered from standard solutions, whereas levels higher than 93% were recovered from the spiked plant samples, with little difference between ethyl acetate and chloroform extractions. In the case of HSE, the recoveries of melatonin were approximately half and never higher than 55%. The ultrasonic treatment proposed in the DSE procedure showed different levels of efficiency (2–20%), depending on the sample.Conclusion – This study has established that, with the direct sample extraction procedure, higher recovery rates are obtained both in standard solutions and in plant samples. The straightforwardness and reproducibility of the extraction procedure is accompanied by the high sensitivity obtained with fluorescence detection. Copyright © 2008 John Wiley & Sons, Ltd.
Molekularpudding
Authors: Vilgis Thomas 
Published: July 2008

AbstractDer Begriff Pudding weckt sicher viele Kindheitserinnerungen und ist vor allem mit einem besonders cremig‐elastischen Mundgefühl verbunden. Pudding kochen war aber auch stets eine zeitraubende Angelegenheit, zumindest ohne Puddingpulver. Moderne Hydrokolloide, Polyelektrolyte und andere essbare Polymere erlauben ein weites Experimentierfeld für Puddings und Cremes, die nur noch gerührt und nicht mehr erwärmt werden müssen.
Mechanism of nucleophilic substitutions at phenacyl bromides with pyridines. A computational study of intermediate and transition state
Authors: Fábián Attila , Ruff Ferenc , Farkas Ödön 
Published: July 2008

AbstractDFT computations have been performed on nucleophilic substitutions of phenacyl bromides with pyridines to investigate the mechanism of the reaction. In contrast with earlier suppositions, tetrahedral intermediate is not formed by the addition of pyridine on the CO group of phenacyl bromide, because the total energy of the reacting species increases continuously, when the distance between the N and C(O) atoms of reactants is shorter than 2.7 Å. At a greater distance, however, a bridged complex of the reactants is observed, in which the N atom of pyridine is slightly closer to the C atom of the CO, than to the C atom of the CH2Br group of phenacyl bromide, the distances are 2.87 and 3.05 Å, respectively. The attractive forces between the oppositely polarized N and C(O) atoms in the complex decrease the free energy of activation of the SN2 attack of pyridine at the CH2Br group. The calculated structural parameters of the SN2 transition states (TS) indicate, that earlier TSs are formed when the pyridine nucleophile bears electron‐donating (e‐d) groups, while electron‐withdrawing (e‐w) groups on phenacyl bromide substrate increase the tightness of the TS. Free energies of activation computed for the SN2 substitution agree well with the data calculated from the results of kinetic experiments and correlate with the σPy substituent constants, derived for pyridines, and with the Hammett σ constants, when the substituents (4‐MeO‐4‐NO2) are varied on the pyridine or on the phenacyl bromide reactants. Copyright © 2008 John Wiley & Sons, Ltd.
Exploring the reaction of iodine with α‐diazo esters
Authors: Verardo Giancarlo , Geatti Paola , Gambi Alberto 
Published: July 2008

AbstractIn this paper we describe the unprecedented reaction between α‐diazo esters 1 and iodine. The reaction, carried out in the presence of aqueous NaHCO3, afforded the Z‐isomer of the corresponding unsaturated‐2‐iodo ester 8. The configuration of compounds 8 was determined using the 3JCH coupling between carbonyl carbon atom and alkene proton. Mechanistic considerations accounting for the observed phenomena and including quantum chemical calculations are proposed. Copyright © 2008 John Wiley & Sons, Ltd.
Knowledge, attitude and willingness of Nigerian physiotherapists to provide care for patients living with Acquired Immunodeficiency Syndrome
Authors: Oyeyemi Adetoyeje , Oyeyemi Adewale , Abegunde Alfred 
Published: July 2008

AbstractBackground and Purpose. Adequate knowledge, positive attitude, and willingness to provide services are important factors in rendering competent and compassionate care to patients living with Acquired Immunodeficiency Syndrome (AIDS). Inadequate knowledge and poor attitude could exclude the application of the principles of logic and scientific methods to the practice of physiotherapy, and could result in fragmented care, with a potentially negative impact on treatment outcome and patient satisfaction. The purpose of this study was (1) to investigate the Nigerian physiotherapists' global knowledge, attitude and willingness to provide care for patients living with AIDS (PLWA), and to (2) determine the relationship between socio‐demographic variables and previous encounter with PLWA, and physiotherapists' knowledge, attitude and willingness to care for AIDS survivors. Methods. Using a 90‐item two‐part questionnaire that elicited sociodemographic and previous AIDS encounter information, and also assessed knowledge, attitude and willingness to provide care to PLWA, physiotherapists (N = 131) practicing in Nigeria were surveyed. Results. Overall, the physiotherapists showed unsatisfactory knowledge about AIDS, harbored negative attitude towards PLWA, and some were unwilling to provide care for PLWA. Previous experience caring for PLWA influenced their attitude, and modest but positive relationships were found between knowledge and attitude and between attitude and willingness. Conclusion. The study underscores the need to address Nigerian physiotherapists' working knowledge deficits and negative attitudes to PLWA. A comprehensive AIDS education that would assist clinicians in exploring their attitude, stereotype and bias against PLWA is warranted. Copyright © 2008 John Wiley & Sons, Ltd.
Discovery of sarcosine dimethylglycine methyltransferase from Galdieria sulphuraria
Authors: McCoy Jason G. , Bailey Lucas J. , Ng Yi Han , Bingman Craig A. , Wrobel Russell , Weber Andreas P. M. , Fox Brian G. , Phillips George N. 
Published: July 2008

AbstractAn enzyme with sarcosine dimethylglycine methyltransferase (SDMT) activity has been identified in the thermophilic eukaryote, Galdieria sulphuraria. The crystal structure of the enzyme, solved to a resolution of 1.95 Å, revealed a fold highly similar to that of mycolic acid synthases. The kcat and apparent KM values were 64.3 min−1 and 2.0 mM for sarcosine and 85.6 min−1 and 2.8 mM for dimethylglycine, respectively. Apparent KM values of S‐adenosylmethionine were 144 and 150 μM for sarcosine and dimethylglycine, respectively, and the enzyme melting temperature was 61.1°C. Modeling of cofactor binding in the active site based on the structure of methoxy mycolic acid synthase 2 revealed a number of conserved interactions within the active site. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Identification and characterization of folding inhibitors of hen egg lysozyme: An example of a new paradigm of drug design
Authors: Caldarini M. , Vasile F. , Provasi D. , Longhi R. , Tiana G. , Broglia R. A. 
Published: July 2008

AbstractStudies of protein folding indicate the presence of native contacts in the denatured state, giving rise to folding elements which contribute to the accomplishment of the native state. The possibility of finding molecules which can interact with specific folding elements of a target protein preventing it from reaching its native state, and hence from becoming biologically active, is particularly attractive. The notion that folding elements not only provide molecular recognition directing the folding process, but also have conserved sequence, implies that targeting such elements will make protein folding inhibitors less susceptible to mutations which, in many cases, abrogate drug effects. The folding‐inhibition strategy can lead to a truly novel and rational approach to drug design, aside from providing new insight into folding. This is illustrated in the case of hen egg lysozyme. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Using distances between α‐carbons to predict protein structure
Authors: Crecca Christina R. , Roitberg Adrian E. 
Published: July 2008

AbstractKnowledge of a protein's structure is important in understanding its function. The usual experimental structure determination methods can be costly and time‐consuming. We present an idea for a fast and inexpensive protein structure prediction method that combines modeling with less expensive experimental data. Our method involves three steps: (1) building a decoy set, (2) measuring inter‐residue distances in a target protein, and (3) comparing the measured distances with those calculated in each decoy. We postulate that structures with a small number of similar inter‐residue distances will also have similar three‐dimensional structure. We further hypothesize that the minimum number of distances needed to determine structure is much less than the total number of inter‐residue distances in the protein. To develop our protocol, we apply our method to target proteins whose structures have been solved experimentally but have not been included in the set. We simulate experimental data by calculating α‐carbon distances from the experimentally determined structures of our target proteins. We have created a large, generalized decoy set using most of the structures in the Protein Data Bank. It can be used to study any protein composed of 100 residues or less. Using this decoy set, we searched for four proteins; our predicted structures ranged in RMSD from 3.6 to 7.7 Å. We have also analyzed the RMSD distributions of the decoys using the search proteins as references and found the distributions to be similar for each protein. Of the nearly 5,000 CαCα distances in a 100 residue protein, knowledge of only twenty‐five distances will usually result in predicting a reliable model. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
The thermal set point of water vapor and life in the condensed state
Authors: Chun Paul W. 
Published: July 2008

AbstractApplication of the Planck–Benzinger thermal work function to biological systems has demonstrated a basic pattern for life processes, in that there is a lower cutoff point, Th, where entropy is favorable but enthalpy is unfavorable, i.e. ΔH0(Th)(+) = TΔS0(Th)(+), and upper cutoff, Tm, above which enthalpy is favorable but entropy unfavorable, i.e. ΔH0(Tm)(−) = TΔS0(Tm)(−). Only between these two limits, where ΔG0(T) = 0, is the net chemical driving force favorable for interacting biological processes. In the case of water vapor condensation, the compensatory temperatures, Th and Tm, are 30 K and 380 K. As water is a part of every living system, this suggests that the single point at which the system is its most stable, defined as the thermal set point, TS, must fall between the limits defined by the compensatory temperatures, 30 K and 380 K. We find that each interacting biological system will exhibit a negative minimum of Gibbs free energy change at a single well‐defined temperature, TS, where the bound unavailable energy TΔS0 = 0. At this point, ΔH0(TS)(−) = ΔG0(TS)(−)minimum, the maximum work can be accomplished. For water vapor condensation, the thermal set point falls at 260 K and TCp at ΔCp0(T) = 0 is 130 K. In examining interacting protein systems, it would appear that the heat capacity change of reaction of water within the system determines the behavior of the other thermodynamic functions. It is clear that the requirements for the existence of a condensed state of water and the existence of life are essentially the same, and are uniquely linked to a characteristic thermal set point. Without the existence of a condensed state, life would not exist. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Ab initio modeling of noncontact atomic force microscopy imaging of benzene on Cu(110) surface
Authors: Atodiresei N. , Caciuc V. , Hölscher H. , Blügel S. 
Published: July 2008

AbstractThe imaging of the detailed atomic structure of single organic molecules adsorbed on a surface is still a challenge for noncontact atomic force microscopy (NC‐AFM). To investigate such a NC‐AFM imaging process, we performed ab initio calculations to simulate the interaction of clean silicon tips with a benzene molecule adsorbed on a Cu(110) surface. The apex structure of the AFM tip was modeled by Si4H3 and Si4H9 clusters. These two nanotips were approached on top of three different molecular sites. The forces acting on the Si4H3 nanotip are always repulsive and lead to a displacement of the benzene molecule on the Cu(110) surface. On the contrary, the forces acting on the Si4H9 nanotip can be attractive or repulsive depending on the approaching molecular site. In this case, the benzene molecule can bind to the tip and is retracted from the surface. The different behavior of the two nanotips considered in our study is analyzed in the framework of the frontier orbital theory. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Electric quadrupole oscillator strengths of helium
Authors: Alexander S. A. , Coldwell R. L. 
Published: July 2008

AbstractUsing a set of explicitly correlated trial wave functions that describe the three lowest singlet and triplet states of the helium atom with symmetry S, P, and D, we calculate the electric quadrupole oscillator strengths for all possible 1S‐1D, 1P‐1P, 1D‐1D, 3S‐3D, 3P‐3P, and 3D‐3D transitions and compare their accuracy to our earlier calculations of the electric dipole oscillator strengths. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Carbon‐donated hydrogen bonding: Electrostatics, frequency shifts, directionality, and bifurcation
Authors: Compaan Katherine , Vergenz Robert , Von Rague Schleyer Paul , Arreguin Isis 
Published: July 2008

AbstractStructure, energies, electrostatics, and vibrational modes were calculated ab initio for dimethyl sulfoxide (DMSO) and its 1:1 hydrogen bonded complex with chloride ion at the MP2/6‐311+G** level. The interaction energy is −71.476 kJ/mole. On average, the CH stretching frequencies decreased by 35 cm−1, whereas their intensities increased by a factor of 19. Methyl torsion frequencies increased by 50–80 cm−1. We review the past and present understanding of hydrogen bonding, and apply these perspectives to analyze properties of the complex. The stretching shifts conform to the established spectral criteria for hydrogen bonding. The bifurcated geometry of the complex and its electrostatic character are fully consistent with trends observed in classically defined hydrogen bonds. All of the established definitions and criteria for identifying hydrogen bonding have been challenged. By any of the most well‐established criteria, the DMSO/Cl− complex is hydrogen bonded. We propose a generally applicable working definition of hydrogen bonding to clarify and unify understanding of this interaction. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Virtual space reduction in quasi‐particle electron propagator calculations: Applications to polycyclic aromatic hydrocarbons
Authors: Dolgounitcheva O. , Flores‐Moreno R. , Zakrzewski V. G. , Ortiz J. V. 
Published: July 2008

AbstractRecently developed techniques of virtual space reduction in quasi‐particle electron propagator calculations are applied to naphthalene, anthracene, phenanthrene, naphthacene, pentacene, and hexacene. Electron density difference matrices corresponding to second‐order transition energies are used to reduce the rank of the virtual orbital space for further electron propagator calculations in the partial third‐order approximation. Within this approach, only minor deviations from ionization energies obtained with the full virtual orbital space are introduced. Comparison is made with a conventional, energy‐based virtual orbital space contraction. No more than 0.14 eV of the calculated ionization energy is lost when the virtual space's dimension is reduced by 50%. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Correlation studies in weakly confining quantum dot potentials
Authors: Kimani Peter , Jones Preston , Winkler Peter 
Published: July 2008

AbstractWe investigate the electron correlation in few‐electron closed‐shell atomic systems and similarly in few‐electron quantum dots under weak confinement. As usual we start with restricted Hartree–Fock (HF) calculations and add electron correlation in steps in a series of approximations based on the single particle Green's function approach: (i) second‐order Green function (GF); (ii) 2ph‐Tamm‐Dancoff approximation (TDA); and (iii) an extended version thereof which introduces ground‐state correlation into the TDA. Our studies exhibit similarities and differences between weakly confined quantum dots and standard atomic systems. The calculations support the application of HF, GF, and TDA techniques in the modeling of three‐dimensional quantum dot systems. The observed differences emphasize the significance of confinement and electronic features unique to quantum dots, such as the increased binding of electrons with higher angular momentum and thus—compared to atomic systems—modified shell‐filling sequences. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008