bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phytochemical Modulators of Human Drug Metabolism: Drug Interactions with Fruits, Vegetables, and Botanical Dietary Supplements
Authors: Gurley Bill , Fifer Kim E. , Gardner Zöe 
Published: May 2012

AbstractPlant secondary metabolites (PSMs) have been components of man's diet for millennia and are believed to have played a significant role in steering the functional development of xenobiotic metabolizing enzymes (XMEs) and transporters within the human gastrointestinal tract. Only recently, however, PSMs have been recognized as modulators of human drug disposition. Despite exposure to thousands of structurally diverse dietary phytochemicals, only a few appear to significantly modulate human drug‐metabolizing enzymes and transporters. In some instances, these interactions may have beneficial effects, such as cancer prevention (i.e., isothiocyanates in cruciferous vegetables), whereas others may dramatically affect the pharmacokinetics of concomitantly administered drugs (i.e., furanocoumarins in grapefruit juice). In today's global economy, the opportunity for exposure to more exotic phytochemicals is significantly enhanced. Formulated as concentrated phytochemical extracts, botanical dietary supplements are vehicles for a host of PSMs rarely encountered in the normal diet. When taken with conventional medications, botanical dietary supplements may give rise to clinically significant herb–drug interactions. These interactions stem from phytochemical‐mediated induction and/or inhibition of human drug‐metabolizing enzymes and transporters.In this chapter, the herb–drug interaction risks and mechanisms for several of the most popular dietary supplements are discussed. Botanicals most likely to produce clinically important herb–drug interactions are those whose phytochemicals act as mechanism‐based inhibitors of cytochrome P450 enzyme (CYP) activity (e.g.,Hydrastis canadensis, Piper nigrum,andSchisandra chinensis) or function as ligands for orphan nuclear receptors (e.g.,Hypericum perforatum). In addition, several external factors unrelated to phytochemical pharmacology can augment the drug interaction potential of botanical supplements.
Inductively Coupled Plasma Mass Spectrometry for Analysis of Metal‐Containing Pharmaceuticals
Authors: Gammelgaard Bente , Stürup Stefan , Møller Charlotte 
Published: May 2012

AbstractThis chapter presents and overview of the ICP‐MS instrumentation and the hyphenation of this detection method to the separation methods CE and HPLC for analysis of metal based drugs and their interactions with biomolecules. Advantages and limitations of the separation methods and their hyphenations are described. Examples of applications are given for the most frequently analysed drugs based on platinum, gold, ruthenium are given.
Clinical Aspects of Drug Biotransformation: An OverviewDedicated to the memory of Mark J. Winn, Ph.D.,1960–1993
Authors: Coleman Michael D. , Radulovic Louis L. 
Published: May 2012

AbstractThe success of a new drug largely depends on the lessons learned from both existing successful and unsuccessful drugs. Although there are many factors that govern the overall effectiveness of a particular agent, its presence for a period commensurate with optimum efficacy is essential at the receptor or tissue and this is governed by clearance. In turn, clearance depends on the myriad processes of biotransformation, which have evolved to serve the individual through biosynthesis and disposal of vital small molecules. Biotransformation is also tasked with protecting homeostasis from xenobiotic agents by removing them, usually through varying degrees of structural alteration aimed at increasing water solubility that promotes renal excretion. This chapter is intended to provide an overview of the major oxidative, conjugative, and hydrolyzing capabilities of our biotransforming enzyme systems, alongside their impressively flexible and highly adapted means of detecting and monitoring small molecules to be metabolized. The role of biotransformation in the insurance of population survival through genetic enzymatic polymorphisms is also explored and its impact on the individual's treatment experience. The effect on biotransformation of inhibition is discussed, as are the major factors the patient brings to the drug treatment process, such as age, disease, gender, and pregnancy. Finally, how the process of drug discovery accommodates biotransformation is outlined from the perspective of the pharmaceutical industry. Understanding of all these interlocking and complex processes will provide an insight into how mass drug therapy can be harnessed to minimize toxicity and maximize efficacy in the twenty‐first century.
Effects of Liver Disease on Drug Metabolism in Humans
Authors: Tan Hui‐Hui , Schiano Thomas D. 
Published: May 2012

AbstractDrug disposition in humans is influenced by its absorption, volume of distribution, metabolism, and elimination. Drug metabolism involves Phase I and II biotransformations, most of which occur in the human liver. This chapter focuses on how physiological states may affect hepatic metabolism and the impact of liver disease on drug handling. The liver is vulnerable to a wide variety of insults, but the repertoire of its response to injury is limited. Likewise, the functional consequences of liver disease on drug disposition are determined by the extent of the injury, as opposed to its etiology. Predicting drug metabolism in patients with liver disease is particularly challenging. No universal rule can be applied to the modification of drug dosages in patients with liver disease.
Role of Metabolism in Toxicity of Drugs in Humans
Authors: Kalgutkar Amit S. , Bauman Jonathan N. 
Published: May 2012

Abstract
Because of the inability to predict and quantify the risk of idiosyncratic adverse drug reactions (IADRs) and because reactive metabolites as opposed to the parent molecules from which they are derived are thought to be responsible for the pathogenesis of some IADRs, procedures (reactive metabolite trapping and/or covalent binding) are being incorporated into the discovery screening funnel early on to assess the risk of reactive metabolite formation. Utility of the methodology in structure–toxicity relationships and scope in abrogating the formation reactive metabolites at the lead optimization stage are discussed in this chapter. Interpretation of the output from reactive metabolite assessment assays, however, is confounded by the fact that many successfully marketed drugs are false positives. Therefore, caution must be exercised in deprioritizing a compound based on a positive result, so that the development of a useful and potentially profitable compound will not be unnecessarily halted. Risk mitigation strategies (e.g. competing detoxication pathways, low daily dose, etc.) when selecting reactive metabolite positive for clinical development are also discussed.
Silicon Fluorides for Acid‐Base Catalysis in Glycosidations
Authors: Kumar Amit , Geng Yiqun , Schmidt Richard R. 
Published: May 2012

AbstractAdduct formation between alcohols as glycosyl acceptors and phenylsilicon trifluoride (PhSiF3) as catalyst permits acid‐base‐atalyzed glycosidations with O‐glycosyl trichloroacetimidates as glycosyl donors. In this way, from various glycosyl donors and acceptors 1,2‐trans‐ and some 1,2‐cis‐glycosides could be obtained with high anomeric selectivity. A preference for an intramolecular bimolecular nucleophilic substitution (SN2‐type) reaction course with concomitant donor and acceptor activation is supported by the results.
Iron(III) Chloride‐Catalysed Aerobic Reduction of Olefins using Aqueous Hydrazine at Ambient Temperature
Authors: Lamani Manjunath , Ravikumara Guralamata S. , Prabhu Kandikere Ramaiah 
Published: May 2012

AbstractA chemoselective reduction of olefins and acetylenes is demonstrated by employing catalytic amounts of ferric chloride hexahydrate (FeCl3⋅6 H2O) and aqueous hydrazine (NH2NH2⋅H2O) as hydrogen source at room temperature. The reduction is chemoselective and tolerates a variety of reducible functional groups. Unlike other metal‐catalysed reduction methods, the present method employs a minimum amount of aqueous hydrazine (1.5–2 equiv.). Also, the scope of this method is demonstrated in the synthesis of ibuprofen in aqueous medium.
Coating die design for suspensions
Authors: Lin Yu‐Yan , Wu Ping‐Yao , Liu Ta‐Jo , Hsu Tong C. , Tiu Carlos 
Published: May 2012

ABSTRACTA novel idea was proposed to the design of a coating die for delivering suspensions. In addition to considering the lateral flow uniformity of the liquid sheet, particle sedimentation is also avoided by maintaining high shear rates inside the die. Only two shims are designed to deliver the coating suspensions, and these two shims are easy to make and flexible for replacement. Two theoretical tools were developed for die design, i.e., one‐dimensional lubrication approximation combined with the optimal design and three‐dimensional finite element simulation. The coating suspension was assumed to obey the Bingham model. It was found that the one‐dimensional lubrication approximation can offer the basic optimal design, whereas edge effects can be minimized through three‐dimensional finite element corrections. Three experimental dies were built: a T‐die, a fishtail die and a coat hanger die based on the optimal design. Experimental results verified the theoretical predictions. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Interfacially confined RAFT miniemulsion copolymerization of styrene and butadiene
Authors: Yu Yitao , Zhang Qinghua , Zhan Xiaoli , Chen Fengqiu 
Published: May 2012

AbstractIn this study, ammonolyzed poly(styrene‐alt‐maleic anhydride) terminated with dithioester group can be self‐assembled into an amphiphilic macro‐reversible addition‐fragmentation chain transfer (RAFT) agent, and RAFT group will be located in the interface of oil and water. RAFT polymerization of styrene (S) and butadiene (B) will be confined in the interface. The main work is to study the effect of degree of aminolysis, reaction temperature, and ratio of S/B on the polymerization kinetics and living characters. The experimental results revealed that aminolysis of dithioester group would lead to retardation and loss of living characters under higher degree of aminolysis. Interfacially confined RAFT miniemulsion polymerizations were of relatively good controlled/living characters under lower degree of aminolysis before gelation. Increase of reaction temperature and ratio of S/B will accelerate the formation of gelation. Finally, styrene/butadiene copolymer nanoparticles with uniform particle size were formed, and because of microphase segregation “core–shell” morphology with polybutadiene core and polystyrene shell was seen obviously. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Shape Analysis of the Corpus Callosum and Cerebellum in Female MS Patients with Different Clinical Phenotypes
Authors: Sigirli Deniz , Ercan Ilker , Ozdemir Senem Turan , Taskapilioglu Ozlem , Hakyemez Bahattin , Turan Omer Faruk 
Published: May 2012

AbstractThe aim of this study was to investigate the shape differences in the corpus callosum (CC) and cerebellum of female relapsing‐remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS) patients compared with healthy controls. This study was conducted using the magnetic resonance imaging scans of 15 control subjects, 26 RRMS, and 14 SPMS patients. The data obtained from the landmark coordinates were analyzed with statistical shape analysis. The landmarks that were chosen to determine the shape differences of the CC and cerebellum have been identified and used in previous studies. In addition to these landmarks, constructed landmarks were determined and used to assess regional shape differences better. The shapes of the CC and cerebellum showed statistically significant differences from the controls when compared with both the RRMS and SPMS patients. It was found that the deformation observed from controls to SPMS was greater than the deformation from controls to RRMS, both for the CC and cerebellum. In conclusion, this study revealed CC and cerebellar shape change in RRMS and SPMS, and showed that deformations both in CC and cerebellum advances with the disease progression. Anat Rec, 2012. © 2012 Wiley‐Periodicals, Inc.
Temporal Dynamics of Cooperation
Authors: Locey Matthew L. , Rachlin Howard 
Published: May 2012

ABSTRACTParties in real‐world conflicts often attempt to punish each other's behavior. If this strategy fails to produce mutual cooperation, they may increase punishment magnitude. The present experiment investigated whether delay reduction—potentially less harmful than magnitude increase—would generate mutual cooperation as interactions are repeated. The participants played a prisoner's dilemma game against a computer that played a tit‐for‐tat strategy, cooperating after a participant cooperated, defecting after a participant defected. For half the participants, the delay between their choice and the computer's next choice was long relative to the delay between the computer's choice and their next choice. For the other half, long and short delays were reversed. The tit‐for‐tat contingency reinforces the other player's cooperation (by cooperating) and punishes the other player's defection (by defecting). Both the rewards and the punishments are discounted by delay. Consistent with delay discounting, the participants cooperated more when the delay between their choice and the computer's cooperation (reward) or defection (punishment) was relatively short. These results suggest that, in real‐world tit‐for‐tat conflicts, the decreasing delay of reciprocation or retaliation may foster mutual cooperation as effectively as (or more effectively than) the more usual tactic of increasing magnitude of reciprocation or retaliation. Copyright © 2011 John Wiley & Sons, Ltd.
Dual‐domain deformation transfer for triangular meshes
Authors: Zhao Yong , Pan Bin , Xiao Chunxia , Peng Qunsheng 
Published: May 2012

ABSTRACTCreating an attractive mesh animation is a laborious and time‐consuming task. In this paper, we propose a practical deformation transfer algorithm to make it easier. To achieve a robust numerical solver, we perform the transfer process in the dual domain; that is, the deformations are transferred between the dual meshes of the source and target meshes. Firstly, the source animation is analyzed and visualized to help the user specify markers in the large deformation regions. Then, through respecting the coherence information, a fast and deformation‐aware surface correspondence approach is presented to determine how the source animation is transferred. Finally, the transferred result can be reconstructed via dual Laplacian optimization. Various experimental results demonstrate the effectiveness and applicability of this paper. Moreover, a user study is carefully designed to perceptually validate our motivation and advantages. Copyright © 2012 John Wiley & Sons, Ltd.
Expanding the Horizon of the Thymine Isostere Biochemistry: Unique Cyclobutane Dimers Formed by Photoreaction between a Thymine and a Toluene Residue in the Dinucleotide Framework
Authors: Liu Degang , Zhou Yan , Pu Jingzhi , Li Lei 
Published: May 2012

AbstractSubstituted toluenyl groups are considered as close isosteres of the thymine residue. They can be recognized by DNA polymerases as if they were thymine. These toluene derivatives are generally inert toward radical additions, including the [2+2] photo‐cycloadditions, due to the stable structure of the aromatic ring and are usually used as solvents for radical reactions. Surprisingly, after incorporating toluene into the dinucleotide framework, we found that the UV excited thymine residue readily dimerizes with the toluenyl moiety through a [2+2] photo‐addition reaction. Furthermore, the reaction site on the toluenyl moiety is not the C5C6 bond, as commonly observed in cyclobutane pyrimidine dimers, but the C4C5 or C3C4 instead. Such a reaction pattern suggests that in the stacked structure, it is one of these bonds, not the C5C6, that is close to the thymine C5C6 bond. A similar structural feature is found in DNA duplex with a thymine replaced by a 2,4‐difluorotoluene. Our results argue that although the substituted toluenyl moieties closely mimic the size and shape of the thymine residue, their more hydrophobic nature determines that they stack on DNA bases differently from the natural thymine residue and likely cause local conformational changes in duplex DNA.
On the transmission opportunity and TCP throughput in cognitive radio networks
Authors: Wang Jian , Huang Aiping , Wang Wei , Zhang Zhaoyang , Lau Vincent K.N. 
Published: May 2012

SUMMARYThe characteristics of cognitive radio networks have huge impacts on the end‐to‐end performance of the transmission control protocol (TCP) for secondary users. Thus, the existing TCP throughput expression, widely used in wired and wireless networks, is no longer suitable for cognitive radio networks. In this paper, we derive the transmission opportunity of secondary users, taking into account the dynamics of spectrum availability, the overhead and errors of spectrum sensing, as well as the interaction between TCP and lower layers. The amount of transmission opportunity is expressed in terms of effective data transmission time. On the basis of the analysis of the transmission opportunity, an expression of an effective TCP throughput is then derived. To evaluate this effective TCP throughput expression, two cross‐layer optimization problems are formulated as application examples to maximize the transport layer effective throughput and energy utility, respectively. Simulation results show that our analysis on transmission opportunity is accurate, and the derived effective TCP throughput expression is more precise than existing ones. Copyright © 2012 John Wiley & Sons, Ltd.
Study on the influence of ageing on thermal decomposition of double‐base propellants and prediction of their in‐use time
Authors: Trache Djalal , Khimeche Kamel 
Published: May 2012

ABSTRACTA comparative study of the thermal decomposition of naturally and artificially aged double‐base propellants has been carried out at five different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry (DSC) technique. The results show that there is only one decomposition peak on DSC curves, and this decomposition has been accelerated by ageing. The influence of the heating rate on the DSC behaviour of the propellants was verified. The kinetic parameters such as activation energy and frequency factor and the thermodynamic parameters such as the enthalpy of activation, free energy of activation and critical explosion temperature for the compounds were obtained from DSC data using non‐isothermal methods proposed by Kissinger and Ozawa. On the other hand, a prediction of the in‐service period by van't Hoff's equation was performed and compared with the experimental results in order to check the constancy and validity of this method. As a result, the prediction procedure used to obtain the time–temperature profile was achieved with good accordance. Copyright © 2012 John Wiley & Sons, Ltd.
A new species and a new combination of Minuartia L. (Caryophyllaceae) from NE Iran
Authors: Mostafavi Golaleh , Assadi Mostafa , Nejadsattari Taher , Sharifnia Fariba , Joharchi Mohammad R. , Mehregan Iraj 
Published: May 2012

AbstractMinuartia khorassanica is introduced and described as a new species. The species has a limited distribution in E. Iran close to the Afghanistan frontier. Minuartia afghanica Rech. f. from Afghanistan and Pakistan is morphologically related to the new species but it is not known in Iran. The most important differences between the new species and M. afghanica are mainly in the shape of sepals and leaves and pedicel length. Moreover the two species have quite distinct ranges. Minuartia lineata Bornm. is another relative of the new species differing from it mainly in reproductive characters. The new species is illustrated and compared with M. lineata based on seed and pollen grain data. An identification key to distinguish these three species is given.In addition, Minuartia litwinowii Schischk. from Turkmenistan and adjacent areas in Iran is reduced to the rank of subspecies as M. lineata subsp. litwinowii. Identification key and selected specimens are given for the two subspecies of M. lineata. The distribution map of all taxa is presented. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Valine but not leucine or isoleucine supports neurotransmitter glutamate synthesis during synaptic activity in cultured cerebellar neurons
Authors: Bak Lasse K. , Johansen Maja L. , Schousboe Arne , Waagepetersen Helle S. 
Published: May 2012

AbstractSynthesis of neuronal glutamate from α‐ketoglutarate for neurotransmission necessitates an amino group nitrogen donor; however, it is not clear which amino acid(s) serves this role. Thus, the ability of the three branched‐chain amino acids (BCAAs), leucine, isoleucine, and valine, to act as amino group nitrogen donors for synthesis of vesicular neurotransmitter glutamate was investigated in cultured mouse cerebellar (primarily glutamatergic) neurons. The cultures were superfused in the presence of 15N‐labeled BCAAs, and synaptic activity was induced by pulses of N‐methyl‐D‐aspartate (300 μM), which results in release of vesicular glutamate. At the end of the superfusion experiment, the vesicular pool of glutamate was released by treatment with α‐latrotoxin (3 nM, 5 min). This experimental paradigm allows a separate analysis of the cytoplasmic and vesicular pools of glutamate. Amount and extent of 15N labeling of intracellular amino acids plus vesicular glutamate were analyzed employing HPLC and LC‐MS analysis. Only when [15N]valine served as precursor did the labeling of both cytoplasmic and vesicular glutamate increase after synaptic activity. In addition, only [15N]valine was able to maintain the amount of vesicular glutamate during synaptic activity. This indicates that, among the BCAAs, only valine supports the increased need for synthesis of vesicular glutamate. © 2012 Wiley Periodicals, Inc.
Snowy plover nest site selection, spatial patterning, and temperatures in the Southern High Plains of Texas
Authors: Saalfeld Sarah T. , Conway Warren C. , Haukos David A. , Johnson William P. 
Published: May 2012

AbstractSnowy plover (Charadrius nivosus) populations have declined throughout their range, in part because of habitat degradation and poor nest success, making information regarding regionally specific nest site selection and spatial patterns important when considering habitat conservation and management guidelines. We determined nest site selection characteristics (n = 180) and examined spatial patterns (n = 215) of snowy plover nests in saline lakes in the Southern High Plains (SHP) of Texas. At 104 nests, we examined the influence of substrate type on nest temperatures and heat mitigation. Snowy plover nests were more likely to be found near an object, on pebble substrate, and with fewer plants than random sites. High use areas were generally located in areas with pebble substrate and on human‐made or natural islands, berms, and peninsulas. Overall, nests placed on pebble substrate had lower temperatures during the day than nests placed on sand substrates. Nest placement on pebble substrate may be valuable to nesting snowy plovers, providing thermal advantages to incubating adults and depressing potentially high nest predation rates. Management guidelines for this region should emphasize the importance of addressing key elements of snowy plover nesting habitat including the presence of pebble substrate and reducing vegetation encroachment. © 2012 The Wildlife Society.