bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parathyroid hormone signaling via Gαs is selectively inhibited by an NH2-terminally truncated Gαs: Implications for pseudohypoparathyroidism
Authors: Puzhko Svetlana , Goodyer Cynthia Gates , Kerachian Mohammad Amin , Canaff Lucie , Misra Madhusmita , Jüppner Harald , Bastepe Murat , Hendy Geoffrey N 
Published: June 2011

Abstract
Pseudohypoparathyroid patients have resistance predominantly to parathyroid hormone (PTH), and here we have examined the ability of an alternative Gαs-related protein to inhibit Gαs activity in a hormone-selective manner. We tested whether the GNAS exon A/B-derived NH2-terminally truncated (Tr) αs protein alters stimulation of adenylate cyclase by the PTH receptor (PTHR1), the thyroid-stimulating hormone (TSH) receptor (TSHR), the β2-adrenergic receptor (β2AR), or the AVP receptor (V2R). HEK293 cells cotransfected with receptor and full-length (FL) Gαs ± Tr αs protein expression vectors were stimulated with agonists (PTH [10−7 to 10−9 M], TSH [1 to 100 mU], isoproterenol [10−6 to 10−8 M], or AVP [10−6 to 10−8 M]). Following PTH stimulation, HEK293 cells cotransfected with PTHR1 + FL Gαs + Tr αs had a significantly lower cAMP response than those transfected with only PTHR1 + FL Gαs. Tr αs also exerted an inhibitory effect on the cAMP levels stimulated by TSH via the TSHR but had little or no effect on isoproterenol or AVP acting via β2AR or V2R, respectively. These differences mimic the spectrum of hormone resistance in pseudohypoparathyroidism type 1a (PHP-1a) and type 1b (PHP-1b) patients. In opossum kidney (OK) cells, endogenously expressing the PTHR1 and β2AR, the exogenous expression of Tr αs at a level similar to endogenous FL Gαs resulted in blunting of the cAMP response to PTH, whereas that to isoproterenol was unaltered. A pseudopseudohypoparathyroid patient with Albright hereditary osteodystrophy harbored a de novo paternally inherited M1I Gαs mutation. Similar maternally inherited mutations at the initiation codon have been identified previously in PHP-1a patients. The M1I αs mutant (lacking the first 59 amino acids of Gαs) blunted the increase in cAMP levels stimulated via the PTHR1 in both HEK293 and OK cells similar to the Tr αs protein. Thus NH2-terminally truncated forms of Gαs may contribute to the pathogenesis of pseudohypoparathyroidism by inhibiting the activity of Gαs itself in a GPCR selective manner. © 2011 American Society for Bone and Mineral Research
Vitamin D supplementation during pregnancy: Double-blind, randomized clinical trial of safety and effectiveness
Authors: Hollis Bruce W , Johnson Donna , Hulsey Thomas C , Ebeling Myla , Wagner Carol L 
Published: June 2011

Abstract
The need, safety, and effectiveness of vitamin D supplementation during pregnancy remain controversial. In this randomized, controlled trial, women with a singleton pregnancy at 12 to 16 weeks' gestation received 400, 2000, or 4000 IU of vitamin D3 per day until delivery. The primary outcome was maternal/neonatal circulating 25-hydroxyvitamin D [25(OH)D] concentration at delivery, with secondary outcomes of a 25(OH)D concentration of 80 nmol/L or greater achieved and the 25(OH)D concentration required to achieve maximal 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] production. Of the 494 women enrolled, 350 women continued until delivery: Mean 25(OH)D concentrations by group at delivery and 1 month before delivery were significantly different (p &lt; 0.0001), and the percent who achieved sufficiency was significantly different by group, greatest in 4000-IU group (p &lt; 0.0001). The relative risk (RR) for achieving a concentration of 80 nmol/L or greater within 1 month of delivery was significantly different between the 2000- and the 400-IU groups (RR = 1.52, 95% CI 1.24–1.86), the 4000- and the 400-IU groups (RR = 1.60, 95% CI 1.32–1.95) but not between the 4000- and. 2000-IU groups (RR = 1.06, 95% CI 0.93–1.19). Circulating 25(OH)D had a direct influence on circulating 1,25(OH)2D3 concentrations throughout pregnancy (p &lt; 0.0001), with maximal production of 1,25(OH)2D3 in all strata in the 4000-IU group. There were no differences between groups on any safety measure. Not a single adverse event was attributed to vitamin D supplementation or circulating 25(OH)D levels. It is concluded that vitamin D supplementation of 4000 IU/d for pregnant women is safe and most effective in achieving sufficiency in all women and their neonates regardless of race, whereas the current estimated average requirement is comparatively ineffective at achieving adequate circulating 25(OH)D concentrations, especially in African Americans. © 2011 American Society for Bone and Mineral Research
Reaction rate of propene pyrolysis
Authors: Han Peipei , Su Kehe , Liu Yan , Wang Yanli , Wang Xin , Zeng Qingfeng , Cheng Laifei , Zhang Litong 
Published: June 2011

AbstractThe reaction rate of propene pyrolysis was investigated based on the elementary reactions proposed in Qu et al., J Comput Chem 2009, 31, 1421. The overall reaction rate was developed with the steady‐state approximation and the rate constants of the elementary reactions were determined with the variational transition state theory. For the elementary reaction having transition state, the vibrational frequencies of the selected points along the minimum energy path were calculated with density functional theory at B3PW91/6‐311G(d,p) level and the energies were improved with the accurate model chemistry method G3(MP2). For the elementary reaction without transition state, the frequencies were calculated with CASSCF/6‐311G(d,p) and the energies were refined with the multireference configuration interaction method MRCISD/6‐311G(d,p). The rate constants were evaluated within 200–2000 K and the fitted three‐parameter expressions were obtained. The results are consistent with those in the literatures in most cases. For the overall rate, it was found that the logarithm of the rate and the reciprocal temperature have excellent linear relationship above 400 K, predicting that the rate follows a typical first‐order law at high temperatures of 800–2000 K, which is also consistent with the experiments. The apparent activation energy in 800–2000 K is 317.3 kJ/mol from the potential energy surface of zero Kelvin. This value is comparable with the energy barriers, 365.4 and 403.7 kJ/mol, of the rate control steps. However, the apparent activation energy, 215.7 kJ/mol, developed with the Gibbs free energy surface at 1200 K is consistent with the most recent experimental result 201.9 ± 0.6 kJ/mol. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Rapid evaluation of the binding energies between peptide amide and DNA base
Authors: Li Yang , Wang Chang‐Sheng 
Published: June 2011

AbstractThe binding energies and the equilibrium hydrogen bond distances as well as the potential energy curves of 20 hydrogen‐bonded amide–base dimers are evaluated from the analytic potential energy function established in our laboratory recently. The analytic potential energy function is used to calculate the NH···N, NH···OC, CH···N, and CH···OC dipole–dipole attractive interaction energies and CO···OC, NH···HN, and NH···HC dipole–dipole repulsive interaction energies in the 20 dimers composed of DNA bases adenine, guanine, cytosine, or thymine and peptide amide. The calculation results show that the potential energy curves obtained from the analytic potential energy function are in good agreement with those obtained from MP2/6‐311+G** calculations by including the basis set superposition error (BSSE) correction. For all the 20 dimers, the analytic potential energy function yields the binding energies of the MP2/6‐311+G** with BSSE correction within the error limits of 0.50 kcal/mol for 19 dimers, only one difference is larger than 0.50 kcal/mol and the difference is only 0.61 kcal/mol. The analytic potential energy function produces the equilibrium hydrogen bond distances of the MP2/6‐311+G** with BSSE correction within the error limits of 0.030 Å for all the 20 dimers. The analytic potential energy function is further applied to four more complicated DNA base‐peptide amide systems involving amino acid side chain and β‐sheet. The values of the binding energies and equilibrium hydrogen bond distances obtained from the analytic potential energy function are also in good agreement with those obtained from MP2 calculations with the BSSE correction. These results demonstrate that the analytic potential energy function can be used to evaluate the binding energies in hydrogen‐bonded peptide amide–DNA base dimers quickly and accurately. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Importance of CH/π hydrogen bonds in recognition of the core motif in proline‐recognition domains: An Ab initio fragment molecular orbital study
Authors: Ozawa Tomonaga , Okazaki Kosuke , Kitaura Kazuo 
Published: June 2011

AbstractWe examined CH/π hydrogen bonds in protein/ligand complexes involving at least one proline residue using the ab initio fragment molecular orbital (FMO) method and the program CHPI. FMO calculations were carried out at the Hartree–Fock (HF)/6‐31G*, HF/6‐31G**, second‐order Møller–Plesset perturbation (MP2)/6‐31G*, and MP2/6‐31G** levels for three Src homology 3 (SH3) domains and five proline‐recognition domains (PRDs) complexed with their corresponding ligand peptides. PRDs use a conserved set of aromatic residues to recognize proline‐rich sequences of specific ligands. Many CH/π hydrogen bonds were identified in these complexes. CH/π hydrogen bonds occurred, in particular, in the central part of the proline‐rich motifs. Our results suggest that CH/π hydrogen bonds are important in the recognition of SH3 and PRDs by their ligand peptides and play a vital role in the signal transduction system. Combined use of the FMO method and CHPI analysis is a valuable tool for the study of protein/protein and protein/ligand interactions and may be useful in rational drug design. © 2011 Wiley Periodicals, Inc. J Comput Chem 2011
Discrepancy in the near‐solute electric dipole moment calculated from the electric field
Authors: Yang Pei‐Kun 
Published: June 2011

AbstractThe electric dipole momentp(r) was computed as the integral of the permanent dipole moment of the solvent molecule μ(r) weighted by the orientational probability distribution Ω(r;O) over all orientations, whereOis the orientation of the solvent molecule atr. The relationship between Ω(r;O) and the potential of the mean torque was derived;p(r) is proportional to the electric fieldE(r) under the following assumptions: (1) the van der Waals (vdW) interaction is independent of the orientation of the solvent molecule atr; (2) the solvent molecule and its electrical effect are modeled as a point dipole moment; (3) the solvent molecule atris in a region far from the solute; and (4) μE(r) ≪kBT, wherekBis Boltzmann's constant andTis absolute temperature. The errors caused by calculating near‐solute Ω(r) andp(r) fromE(r) are unclear. The results show that Ω(r) is inconsistent with the value calculated fromE(r) for water molecules in the first and second shells of solute with charge stateQ= ±1 e, and a large variation in solvent molecular polarizability γmol(r), which appeared in the first valley of 4πr2E(r) for |Q| < 1 e. Nonetheless,p(r) is consistent with the values calculated fromE(r) for |Q| ≤ 1 e. The implication is that the assumptions for calculatingp(r) can be ignored in the calculation of the solvation free energy of biomolecules, as they pertain to protein folding and protein–protein/ligand interactions. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Molecular dynamics simulation reveals structural and thermodynamic features of kinase activation by cancer mutations within the epidermal growth factor receptor
Authors: Wan Shunzhou , Coveney Peter V. 
Published: June 2011

AbstractThe epidermal growth factor receptor (EGFR) is a major target for drugs in treating lung carcinoma as it promotes cell growth and tumor progression. Structural studies have demonstrated that EGFR exists in an equilibrium between catalytically active and inactive forms, and dramatic conformational transitions occur during its activation. It is known that EGFR mutations promote such conformational changes that affect its activation and drug efficacy. The most common point mutation in lung cancer patients is a leucine to arginine substitution at amino acid 834 (L834R). In a recent article, we have studied changes in drug binding affinities due to cancer mutations of EGFR using ensemble molecular dynamics (MD) simulations. Here, we address an enhanced activation mechanism thought to be associated with this mutation. Using extended timescale MD simulations, the structural and energetic properties are studied for both active and inactive conformations of EGFR. The thermodynamic stabilities of these two conformations are characterized by free energy landscapes estimated from molecular mechanics/Poisson–Boltzmann solvent area calculations. Our study reveals that the L834R mutation introduces conformational changes in both states, adjusting the relative stabilities of active and inactive conformations and hence the activation of the EGFR kinase. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Utilization of personal therapy by psychotherapists: a practice‐friendly review and a new study
Authors: Orlinsky David E. , Schofield Margot J. , Schroder Thomas , Kazantzis Nikolaos 
Published: June 2011

AbstractThis article offers both a practice‐friendly review of research on therapists' personal therapy and a new study of personal psychotherapy among 3,995 psychologists, counselors, social workers, psychiatrists, and nurses in 6 English‐speaking countries. The prevalence of personal therapy as it relates to professional discipline, theoretical orientation, gender, and career level are studied. Findings showed that 87% of the overall sample embarked on personal therapy at least once: 94% of analytic/psychodynamic therapists, 91% of humanistic therapists, 73% of cognitive‐behavioral therapists, 82% of the novice therapists to 89% of senior therapists. Both the existing research and this new study demonstrate the extraordinary commonality of personal therapy among psychotherapists, and encourage further use for professional training, clinical practice, and therapist self‐care. © 2011 Wiley Periodicals, Inc. J Clin Psychol: In Session 67:1–15, 2011.
Mixing and solid‐liquid mass transfer characteristics in a three phase pulsed plate column with packed bed of solids in interplate spaces—a novel aerobic immobilized cell bioreactor
Authors: Kodialbail Vidya Shetty , Srinikethan Govindan 
Published: June 2011

AbstractBACKGROUND: The pulsed plate column (PPC) with packed bed of solids in the interplate spaces finds use as a three phase aerobic bioreactor and is a potential heterogeneous catalytic reactor. Good knowledge of the extent of mixing in the liquid phase and solid‐liquid mass transfer coefficient are essential for modeling, design and optimization of these columns. The present work aims at the study of liquid phase mixing and solid–liquid mass transfer characteristics in a three phase PPC.RESULTS: Residence time distribution studies were performed. Dispersion number was found to increase with increase in liquid superficial velocities, frequency of pulsation, amplitude of pulsation and the vibrational velocities. Increase in frequency and amplitude of pulsation, and hence increase in vibrational velocity, resulted in increase of the solid–liquid mass transfer coefficient.CONCLUSIONS: The mixing behaviour in this contactor approximated a mixed flow behaviour. The three phase PPC was found to outperform many other kinds of three phase contactors in terms of solid liquid mass transfer characteristics. Empirical correlations developed can be used for the determination of solid–liquid mass transfer coefficients for three phase PPC and hence can facilitate the design, scale‐up and modeling of these columns, when used as chemical or biochemical reactors. Copyright © 2011 Society of Chemical Industry
Performance of microwave synthesized dual solvent dope solution and lithium bromide additives on poly(ethersulfone) membranes
Authors: Iqbal Ahmed , Ani I. , Rajput Rizwan 
Published: June 2011

AbstractBACKGROUND: Generally the fabrication of polymeric membranes is a complicated and expensive process since it involves several steps. The preliminary preparation steps involve polymer drying and dissolution and is very time consuming and expensive. Currently, conventional electrothermal heating (CEH) is used to dissolve polyethersulfone in an aprotic solvent for membrane fabrication. Usually CEH requires 6 to 8 h at temperatures of 80 to 95 °C. This paper reports the fabrication and characterization of polyethersulfone (PES) asymmetric ultrafiltration membrane made from microwave (MW) synthesis casting solution consisting of various compositions of double solvents and lithium bromide (LiBr) additive.RESULTS: Homogeneous dual solvent dope solutions prepared via microware irradiation took only 1 h instead of the 7 h when prepared using CEH. The results also revealed that the membrane permeation and rejection rates, pore size and porosity were dependent on the ratio of LiBr to acetone. Membranes with LiBr kept at 2 and 3 wt% exhibited both high rejection and permeation rates with minimum pore sizes of 1.067 and 1.214 nm respectively. The presence of LiBr and the occurrence of chain scission were elucidated using Fourier transform infrared (FTIR) spectroscopy while its hydrophilic property was confirmed by water absorption and contact angle measurements.CONCLUSIONS: It was concluded that the microwave technique is capable of producing 1 L membrane solutions in less than 1 h. The membranes prepared from the microwave solutions show good rejection and permeation rates. Copyright © 2011 Society of Chemical Industry
Management scenarios for olive oil mill waste based on characterization and leaching tests
Authors: Coz Alberto , Villegas Mercedes , Andrés Ana , Viguri Javier R. , Mantzavinos Dionissios , Xekoukoulotakis Nikolaos P. 
Published: June 2011

AbstractBACKGROUND: Olive oil mill waste is a serious environmental problem in the Mediterranean basin given its particular characteristics of high organic content, seasonal and localized generation, and the type of processing involved.RESULTS: Olive mill waste from a three‐phase mill was characterized by means of total analysis, availability and mobility of the pollutants in order to help the decision‐maker about possible options for its valorization and/or disposal. Water content, loss of ignition, total organic carbon, phenol index and metals concentrations were measured to fully characterize the waste. Three leaching tests (NEN 7341, EN 12457 and UNE CEN‐TS 15364 EX) were carried out to evaluate the environmental hazard of the waste material and the leachates were characterized with respect to electric conductivity, pH, heavy metals, anions and organic pollutants (phenol index and total organic carbon) according to European waste directives. The results were compared with EU regulations for inert, non‐hazardous and hazardous waste disposal.CONCLUSION: It was found that not only organic parameters must be taken into account concerning the fate of this waste material, but also the mobility of heavy metals and anions should be studied. Furthermore, stabilization/solidification processes are recommended before landfill disposal of this kind of agro‐waste material. Copyright © 2011 Society of Chemical Industry
Production of bioethanol by immobilized Saccharomyces Cerevisiae onto modified sodium alginate gel
Authors: Inal Murat , Yiğitoğlu Mustafa 
Published: June 2011

AbstractBACKGROUND: Microbial bioethanol production is an important option in view of the finite global oil reserves. Bioethanol fermentation was carried out using immobilized microorganisms (Saccharomyces cerevisiae, Zymomonas mobilis, Pichia stipitis, etc.), which has many advantages compared with the use of free cells. Various support materials have been used for bioethanol fermentation, and alginate gels have been one of the most widely used matrices for cell entrapment. The aim of this study was increased bioethanol production by Saccharomyces cerevisiae immobilized on alginate gels. First, N‐vinyl‐2‐pyrrolidone was grafted onto sodium alginate. Then, the properties of ethanol production were investigated using the matrix obtained.RESULTS: The performance of ethanol fermentation was affected by calcium chloride concentration, N‐vinyl‐2‐pyrrolidone grafted onto the sodium alginate, sugar concentration and the percentage of immobilized cell beads. These effects were optimized to give maximum ethanol production. Ethanol production was accelerated when sodium alginate polymer was modified with N‐vinyl‐2‐pyrrolidone. The maximum concentration, productivity and yield of ethanol were 69.68 g L−1, 8.71 g L−1 h−1 and 0.697 g g−1, respectively.CONCLUSION: The new polymeric matrix, when compared with sodium alginate, showed better ethanol production due to the hydrophilic property of N‐vinyl‐2‐pyrrolidone. The results suggest that the proposed method for immobilization of Saccharomyces cerevisiae has potential in industrial applications of the ethanol production process. Copyright © 2011 Society of Chemical Industry
Selective CO oxidation over monolithic AuMgO/Al2O3 catalysts
Authors: Özdemir Seval , Önsan Zeynep Ilsen , Yıldırım Ramazan 
Published: June 2011

AbstractBACKGROUND: Selective CO oxidation was studied in a hydrogen‐rich environment over monolithic Au/MgO/Al2O3 catalysts at 50–150 °C. The wash‐coating of cordierite monoliths with colloidal Al2O3 was followed by wet impregnation of MgO; the subsequent deposition of Au was achieved using various methods. All catalysts were characterized using ICP and ESEM.RESULTS: Homogenous deposition‐precipitation was found to be the best Au loading method among those tested for monoliths. The CO conversion over 1%(w/w) Au/1.25%(w/w) MgO/Al2O3 was ca 80% at 90 °C. Increasing the Au content of the catalyst from 0.16 to 1.0%(w/w) increased CO conversion and shifted the required temperature to lower values. A similar trend was also observed for maximum CO conversion at increasing W/FCO ratios. The addition of MgO was beneficial for CO conversion.CONCLUSION: Although CO conversion of ca 80% was lower than that achieved with particulate catalysts, it is high enough as a starting point for further improvement considering the superiority of monolithic supports for practical applications. Copyright © 2011 Society of Chemical Industry
The paratympanic organ: a barometer and altimeter in the middle ear of birds?
Authors: von Bartheld Christopher S. , Giannessi Francesco 
Published: June 2011

AbstractA century has passed since the discovery of the paratympanic organ (PTO), a mechanoreceptive sense organ in the middle ear of birds and other tetrapods. This luminal organ contains a sensory epithelium with typical mechanosensory hair cells and may function as a barometer and altimeter. The organ is arguably the most neglected sense organ in living tetrapods. The PTO is believed to be homologous to a lateral line sense organ, the spiracular sense organ of nonteleostean fishes. Our review summarizes the current state of knowledge of the PTO and draws attention to the astounding lack of information about the unique and largely unexplored sensory modality of barometric perception. J. Exp. Zool. (Mol. Dev. Evol.) 316:402–408, 2011. © 2011 Wiley‐Liss, Inc.