bluuebunny/crossref_metadata_2025 huggingface dataset:
Ceria-Based Mixed Oxide Supported Nano-Gold as an Efficient and Durable Heterogeneous Catalyst for Oxidative Dehydrogenation of Amines to Imines Using Molecular Oxygen
Authors: Dar Bashir Ahmad , Sharma Meena , Singh Baldev
Published: October 2012

The present work is intended to determine the catalytic activity of Mixed Oxide supported gold for aerobic oxidative dehydrogenation of amines to imines using Ceria as a main constituent of the each support. The model catalysts Au/CeO2:TiO2 Au/CeO2:SiO2, Au/CeO2:ZrO2 and Au/CeO2:Al2Os were prepared by deposition co-precipitation method and deposition of gold was determined by EDEX analysis. The supported nano-gold catalyzes the dehydrogenation of secondary amines to imines without loss of activity. On recycling good amount of product yield is obtained. Oxidation of secondary amines to imines is carried at 100˚C and almost 90 % conversion was obtained with >99% selectivity. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Short Review: Cu Catalyst for Autothermal Reforming Methanol for Hydrogen Production
Authors: Wu Ho-Shing , Lesmana Donny
Published: October 2012

Hydrogen is a promising alternative energy sources, hydrogen can be used in fuel cell applications to pro-ducing electrical energy and water as byproduct. Therefore, fuel cell is a simple application and environ-mentally friendly oriented technology. Recent years various methods have been conducted to produce hy-drogen. Those methods are derived from various sources such as methanol, ethanol, gasoline, hydrocarbons. This article presents a brief review a parameter process of that affects in autothermal reforming methanol use Cu-based catalysts for production of hydrogen. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts
Authors: Raskar R. Y. , Kale K. B. , Gaikwad A. G.
Published: October 2012

The de-oxygenation of CO2 was explored by using hydrogen, methane, carbon etc., over alumina supported catalysts. The alumina-supported ruthenium, rhodium, platinum, molybdenum, vanadium and magnesium catalysts were first reduced in hydrogen atmosphere and then used for the de-oxygenation of CO2. Furthermore, experimental variables for the de-oxygenation of CO2 were temperature (range 50 to 650 oC), H2/CO2 mole ratios (1.0 to 5), and catalyst loading (0.5 to 10 wt %). During the de-oxygenation of CO2 with H2 or CH4 or carbon, conversion of CO2, selectivity to CO and CH4 were estimated. Moreover, 25.4 % conversion of CO2 by hydrogen was observed over 1 wt% Pt/Al2O3 catalyst at 650 oC with 33.8 % selectivity to CH4. However, 8.1 to 13.9 % conversion of CO2 was observed over 1 wt% Pt/Al2O3 catalyst at 550 oC in the presence of both H2 and CH4. Moreover, 42.8 to 79.4 % CH4 was converted with 9 to 23.1 % selectivity to CO. It was observed that the de-oxygenation of CO2 by hydrogen, carbon and methane produced carbon, CO and CH4. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Synthesis of Fluorite (CaF2) Crystal from Gypsum Waste of Phosphoric Acid Factory in Silica Gel
Authors: Khunur Mohammad Misbah , Risdianto Andri , Mutrofin Siti , Prananto Yuniar Ponco
Published: October 2012

This paper report the synthesis and characterization of fluorite single crystal prepared from gypsum waste of phosphoric acid production in silica gel. Instead of its high calcium, gypsum was used to recycle the waste which was massively produces in the phosphoric acid production. The gypsum waste, the raw material of CaCl2 supernatant, was dissolved in concentrated HCl and then precipitated as calcium oxalate (CaC2O4) by addition of ammonium oxalate. The CaCl2 was obtained by dissolving the CaC2O4 with HCl 3M. The crystals were grown at room temperature in silica gel and characterized by AAS, FTIR and powder XRD. The optimum crystal growth condition, which is pH of gel, CaCl2 concentration and growth time, were investigated. The result shows that at optimum condition of pH 5.80, CaCl2 concentrations of 1.2 M, and growth time of 144 hours, colorless crystals with the longest size of 3 mm, were obtained (72.57%). Characterization of the synthesized crystal by AAS indicates that the obtained crystal has high purity. Meanwhile, analysis by FTIR spectra shows a Ca–F peak at 775 cm-1, and powder-XRD analysis confirms that the obtained crystal was fluorite (CaF2). © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
General Vacuum Techniques
Authors: Peacock Neil T.
Published: October 2012

This article reviews the procedures and equipment used to maintain a vacuum system at pressures in the range from 10−3to 10−11 torr. Equipment covered includes pumps, flanges, and sealing. Common pump types are covered, including details of their principles and technique of operation, as well as their recommended uses. Total and partial pressure gauges used in this range are also described. Common materials for vacuum systems and their properties are summarized along with fabrication methods. Leak detection methods and techniques are presented.
Simulation of Chemical Vapor Deposition Processes
Authors: Kleijn Chris R. , Cavallotti Carlo
Published: October 2012

Chemical vapor deposition (CVD) is probably the most used technology for the growth of high quality thin solid films. It is in fact widely used in the electronic and optoelectronic industry to deposit semiconducting, conducting, and insulating films as well as in the mechanical industry to grow anticorrosion and antiwear coatings on tools and equipment. The success of CVD is determined by its capability to couple reasonably high deposition rates while maintaining high‐level structural and morphological properties of the grown material. The success of CVD processes as well as the continuous increase of deposition rates and of the range of materials that can be grown through this technique relies in part on the availability of powerful modeling tools that simulate the growth process. In the present article, the status of the art of modeling CVD processes is reviewed. Particular emphasis is placed on the multiscale nature of this theoretical field, which encompasses phenomena with characteristic length scales that go from 10–10 to 100 m. In this light, advantages and disadvantages related to the use of modeling tools apt to treat specific length and time scales phenomena relevant to CVD are reviewed and discussed.
Principles and Practices of Thermal Analysis and Calorimetry
Authors: Hill John
Published: October 2012

This article presents a brief introduction to thermal analysis and calorimetry with emphasis on the application of the associated thermoanalytical techniques to the characterization of a wide range of materials over wide temperature ranges. The currently accepted nomenclature for these techniques is given together with the reference materials recommended for calibration. Also, the thermodynamic principles on which these techniques are based are summarized and the major recent literature on thermal analysis and calorimetry is listed together with some relevant internet websites. Essentially, this article constitutes a useful working handbook of thermal analysis and calorimetry.
Differential Scanning Calorimetry and Differential Thermal Analysis
Authors: Schick Christoph , Lexa Dusan , Leibowitz Leonard
Published: October 2012

Differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are effective analytical tools to characterize melting, crystallization, and mesomorphic transitions and to determine the corresponding enthalpy and entropy changes. The glass transition and other effects that show either changes in heat capacity or a latent heat are accessible too. The advantage of DSC and DTA compared to other calorimetric techniques lies in the broad dynamic range regarding heating and cooling rates, including isothermal and temperature‐modulated operation. The broad dynamic range is especially of interest because many materials are commonly used or produced on far from equilibrium routes and transitions are strongly time (rate) dependent.
Generation and Measurement of Magnetic Fields
Authors: Mielke Charles H. , Schneider‐Muntau Hans J. , Coey J. M. D. , Kuhns Phil , Rubin Larry , Schott Chistian
Published: October 2012

In basic science areas, such as semiconductor physics, superconductivity, structural biology, and chemistry, magnetic fields are used as a powerful tool for analysis of matter because they can change the physical state of a system. In the presence of a magnetic field, the angular momenta (spins), the orbital motion of charged particles, and therefore the energy of the investigated physical system, are altered.Wemust realize, however, that the size of the induced effects are very modest compared to other physical quantities. One Bohr magneton (typical range of atomic magnetic moments) in a magnetic field of 10 tesla (T) (a 10 T field is ∼200,000 times the strength of the earth's magnetic field) has an energy of 0.58 meV, corresponding to a temperature of 6.7 K, a small value in comparison to room temperature. On the other hand, the generation of a magnetic field of 10Talready requires a noticeable engineering effort, with continuous fields of 50 T being the upper limit of what can be achieved today. Pulsed magnetic fields can be generated up to 100 T for durations in the millisecond range, and up to 1000 T on the microsecond time scale. Therefore, experiments must be chosen judiciously. Very often, a low‐noise sample environment, such as low mechanical vibrations, small field fluctuations (in the case of dc fields), and low temperatures are decisive to the success of scientific measurements in magnetic fields.
Scanning Electron Microscopy
Authors: Leonard Donovan N. , Chandler Gary W. , Seraphin Supapan
Published: October 2012

The scanning electron microscope (SEM) is one of the most widely used instruments in materials research laboratories and is common in various forms in fabrication plants. Scanning electron microscopy is central to microstructural analysis and therefore important to any investigation relating to the processing, properties, and behavior of materials that involves their microstructure. The SEM provides information relating to topographical features, morphology, phase distribution, compositional differences, crystal structure, crystal orientation, and the presence and location of electrical defects. The SEM is also capable of determining elemental composition of microvolumes with the addition of an x‐ray or electron spectrometer and phase identification through analysis of electron diffraction patterns. The strength of the SEM lies in its inherent versatility due to the multiple signals generated, simple image formation process, wide magnification range, and excellent depth of field.

Lenses in the SEM are not a part of the image formation system but are used to demagnify and focus the electron beam onto the sample surface. This gives rise to two of the major benefits of the SEM: range of magnification and depth of field in the image. Depth of field is that property of SEM images where surfaces at different distances from the lens appear in focus, giving the image three‐dimensional information. The SEM has more than 300 times the depth of field of the light microscope. Another important advantage of the SEM over the optical microscope is its high resolution. Subnanometer resolution at low beam energies (e.g., 1 kV) is now achievable from an SEM with a field emission (FE) electron gun. Magnification is a function of the scanning system rather than the lenses, and therefore a surface in focus can be imaged at a wide range of magnifications. The higher magnifications of the SEM are rivaled only by the transmission electron microscope (TEM), which requires the electrons to penetrate through the entire thickness of the sample. As a consequence, TEM sample preparation of bulk materials is tedious and time‐consuming, compared to the ease of SEM sample preparation, and may damage the microstructure. The information content of the SEM and TEM images is different, with the TEM image showing the internal structure of the material.

Due to these unique features, SEM images frequently appear not only in the scientific literature but also in the daily newspapers and popular magazines. The SEM is relatively easy to operate and affordable and allows for multiple operation modes, corresponding to the collection of different signals. This chapter reviews the SEM instrumentation and principles, its capabilities and applications, and recent trends and developments.
Ion Beam Methods, Introduction
Authors: Jeynes Chris
Published: October 2012

Ion beam techniques are used with ion energies from eV to many MeV and a very wide range of ion species to characterize materials at length scales from sub‐nm to sub‐mm and in a wide variety of different ways. Many of these techniques are non‐destructive.

Atomic concentration can be determined from matrix elements (the stoichiometry) to minor and trace elements (at ng/g sensitivity and better), in one dimension (depth profiles), two dimensions (elemental maps), and three dimensions with full tomography being feasible. There is sensitivity to the whole Periodic Table one way or another, with nuclear techniques for isotopic sensitivity, and high resolution mass spectrometry for obtaining isotopic ratios at ultra‐high sensitivities of 1e14 and better.

Other techniques include ultra‐high resolution microscopy, characterization of semiconductor device defects at high spacial resolution, and the investigation of damage processes in the nuclear irradiation of materials.

Ion beam methods for thin film materials have major application areas from archaeology to zoology (including materials science, geology, cultural heritage, electronics and many others).
Neutron Techniques, Introduction
Authors: Goldman Alan I.
Published: October 2012

This chapter explores the wide range of applications of elastic and inelastic neutron scattering to the study of materials. Neutron scattering provides information complementary to several other techniques found in these volumes. Perhaps most closely related are the electron scattering methods described in Chapter
Electron Techniques
and x‐ray scattering methods described in Chapter
X‐Ray Techniques
. The utility of all these scattering methods in investigations of atomic scale structure arises from the close match of the wavelength of these probes to typical interatomic distances (a few angstroms). The differences between these techniques are discussed.
Neutron Powder Diffraction
Authors: Vogt Thomas
Published: October 2012

The first powder diffraction studies on simple materials such as iron metal using x‐rays were done independently by Debye and Scherrer in Germany and by Hull in the United States. For a long time x‐ray powder diffraction was primarily used for qualitative purposes such as phase identification and the assessment of crystalline quality. The earliest structure determinations using only x‐ray powder diffraction data were done by Zachariasen in 1949, who solved the structures of α‐ and β‐UF5 by an intuitive trial‐and‐error approach. An important subsequent step was taken when Zachariasen and Ellinger solved the monoclinic structure of β‐plutonium using manual direct‐method procedures. The use of neutrons to determine structures using powder diffraction has advanced significantly over the past 60 years. Neutron powder diffraction is complementary to both x‐ray and electron powder diffraction. The greater penetration depth of neutrons, due to the fact that the neutron‐nucleus interaction is a point scattering process implying no variation of the nuclear scattering length with the scattering angle, the independence of the scattering cross‐section from the atomic number (Z) of an element, and therefore the stronger interaction of neutrons with “light” elements such as oxygen and hydrogen, and its isotope specificity as well as its interaction with unpaired electrons (“magnetic scattering”) make neutrons a unique and indispensable probe for structural condensed matter physics and chemistry.
Dynamic Light Scattering
Authors: Sidebottom David
Published: October 2012

Dynamic light scattering is commonly used to monitor the diffusion of small particles in either liquids or aerosols and can be used to evaluate the particle size and distribution of these diffusing particles. However, it is also used to probe the slow dynamics of density fluctuations that are inherent in certain fluids. This includes measures of the diverging correlation length near the critical point of liquid mixtures that exhibit a miscible‐immiscible phase transition and measurements of the tremendously lethargic viscoelastic dynamics seen in supercooled liquids near the glass transition. In this article, the dynamic light scattering technique of photon correlation spectroscopy is described in sufficient detail for a novice to appreciate and likely execute. The theoretical framework for the technique is developed at an introductory level and the relationships between measured intensity‐intensity autocorrelation functions and their corresponding dynamic structure factors are presented. A distinction is drawn between homodyne and heterodyne experiments and the relative merits of each are illustrated by examples. Details of the experimental set up are also reviewed and some of the most common pitfalls and artifacts are discussed.
Measuring the Electronic Properties of Materials at the Nanoscale
Authors: Lauhon Lincoln J.
Published: October 2012

The general objective of electronic property measurements is to relate extrinsic characteristics of devices or test structures to the intrinsic properties of materials. When there are significant nanoscale inhomogeneities in macroscale materials, or the materials themselves are nanoscale, the measurement of electronic properties at high spatial resolution may be essential to the fundamental understanding of structure–property relationships. This chapter is intended to serve as a framework for the consideration of measuring the electronic properties of materials at the nanoscale, and as a guide to the use of other articles in this volume. Background is provided on general principles of nanoscale measurement, approaches to nanofabrication that enable investigation of nanoscale and nanostructured materials, and distinct regimes of transport that inform the interpretation of electrical measurements. Specific techniques that exploit local probe–sample interactions are introduced according to their principles of operation, to either locally measure characteristics of a material or to generate a local perturbation material that is detected remotely. This framework is used to organize the chapter in terms operational mechanisms of techniques, rather than outcomes of measurement. Noncontact measurements that generate knowledge of local electronic properties are also examined. The chapter is not strictly limited to techniques that provide nanoscale resolution, but rather techniques that resolve electronic properties on length scales over which said properties may vary. The chapter focuses on generally accessible measurements of practical importance to understanding and optimizing the properties of materials with readily envisioned applications.
Super‐Resolution Optical Microscopy
Authors: Han Jason J. , Shreve Andrew P. , Werner James H.
Published: October 2012

Far‐field super‐resolution optical microscopy is a young and rapidly developing technology that enables optical imaging with unprecedented sub‐diffraction‐limited spatial resolution. These imaging methods have been developed primarily within the context of biological imaging, but show great potential as a new and complementary tool for characterization of nanostructural material features traditionally inaccessible by conventional optical imaging methods. In this article, we introduce the working principles of super resolution optical microscopy, suggest specific materials that should be good candidates for these new techniques, and discuss practical aspects that should be considered for its implementation for materials characterization.
Reflection High‐Energy Electron Diffraction
Authors: Hasegawa Shuji
Published: October 2012

The fundamentals, experimental techniques, and practical aspects of reflection high‐energy electron diffraction (RHEED) are described with some examples of observations. Actual samples that we deal with in experiments are in many cases far from ideal ones; the surfaces are not perfectly single‐crystalline with infinitely large domains, or not atomically flat. The RHEED patterns are then modified from the theoretical ones for ideal samples. Inversely, from such modifications in the patterns, we can obtain various kinds of information on the atomic structures of surfaces and thin films. Examples of RHEED analyses presented here include monitoring structural phase transitions and epitaxial growth of atomic layers. RHEED has advantages in observing such dynamical phenomena of structure changes.
Secondary Ion Mass Spectrometry
Authors: Watts John F. , Wolstenholme John , Webb Roger P.
Published: October 2012

An overview of secondary ion mass spectrometry (SIMS) is given. It is placed in context of other surface analytical techniques. The SIMS technique is divided into static, dynamic, and imaging SIMS. The basic operations, assumptions, and variations are explained with examples from the scientific literature. Problems associated with interpreting the collected data and the ways in which the data is interpreted are given. The recommendations from ASTM and ISO in the use of SIMS and interpretation of the data are referenced.
Ultrasonic Atomic Force Microscopy
Authors: Yamanaka Kazushi , Tsuji Toshihiro
Published: October 2012

For the development of advanced electronic and mechanical devices on the micro‐ and nanoscale, there is an increasing need for the characterization of elasticity and subsurface defects. As a useful method, principle, implementation, and applications of ultrasonic atomic force microscopy (UAFM) and related methods for elastic materials characterization are described. It measures the contact stiffness from the resonance frequency of cantilever with the tip in contact with the sample surface. We focus on the concept of effective enhancement of the cantilever stiffness caused by the inertia of a soft cantilever at or above the contact resonance frequency. By virtue of this effect, new findings on elasticity of materials were achieved by many groups so far. Relation between UAFM and ordinary atomic force microscopy (AFM) is explained in detail. Also, lateral modulation atomic force microscopy (LM‐AFM) with application to nanotribology is explained.
Magneto‐Optical Characterization of Magnetic Thin Films, Surfaces, and Interfaces at Small Length and Short Timescales
Authors: Kirilyuk Andrei , Kimel Alexey V. , Savoini Matteo , Rasing Theo
Published: October 2012

The understanding of magnetism at its fundamental length and timescales related to the exchange interaction, that is, at nanometer (nm) length and femtosecond (fs) timescales, is becoming essential as future magnetic recording aims at Tbit densities switched at THz rates, which is exactly this regime. Magnetization‐sensitive second harmonic generation (MSHG) is a nonlinear optical technique that, due to the dipole selection rules, is specifically sensitive to surfaces and interfaces of centrosymmetric media. This surface/interface sensitivity of MSHG in combination with very large magneto‐optical effects has lead to a fast development of this technique over the past decade, demonstrating atomic scale resolution in the direction perpendicular to the interfaces. To increase the lateral resolution of magneto‐optics beyond the diffraction limit, scanning near‐field optical microscopy techniques are more appropriate. The development of novel probes that preserve the polarization has led to the possibility of magneto‐optical characterization of magnetic nanostructures with spatial resolution beyond 100 nm. The combination of these and other magneto‐optical techniques with pump–probe approaches finally allows one to include time resolution down to the femtosecond range in the magneto‐optical characterization of magnetic structures. The main attention of the present chapter is on the application of the MSHG, SNOM, and pump–probe techniques to magnetic thin films and surfaces, with a focus on the achieved progress in understanding of magnetic phenomena at the smallest length and shortest timescales. On the one hand, an extreme sensitivity of MSHG to the electronic and magnetic structure of clean surfaces has been successfully demonstrated. On the other hand, the penetration depth of light has allowed to use this sensitivity to study buried interfaces in multilayer systems. Various phenomena, such as surface states on magnetic metals, enhanced magnetic moments of low‐coordinated atoms, and quantum well states, have been studied. Complimentary to these developments, we show how SNOM gives in‐plane information about submicron magnetic domain structures. Finally, we demonstrate how magneto‐optical pump–probe techniques can be used to study the dynamics of magnetic phenomena with a time resolution down to femtoseconds.
Review of Drug Metabolism in Drug Discovery and Development
Authors: White Ronald E.
Published: October 2012

Drug metabolism is the process of chemical conversion of a drug to a metabolite preparatory to its elimination from the body. Four general categories of drug metabolic reactions occur: oxidations, reductions, conjugations, and hydrolyses. Metabolism is an important aspect of the clinical profile of a drug, since it is often a determinant of half‐life, a source of drug–drug interactions, a reason for interindividual variability of drug response, and a source of toxicities.
Extrahepatic Drug‐Metabolizing Enzymes and Their Significance
Authors: Jhajra Shalu , Ramesh Varkhede Ninad , Suresh Ahire Deepak , Vidyasagar Naik Bukke , Prasad Bhagwat , Paliwal Jyoti , Singh Saranjit
Published: October 2012

Drug‐metabolizing enzymes (DMEs) are primarily expressed in the liver but their role in the extrahepatic tissues such as gastrointestinal tract (GIT), pulmonary, excretory, nervous, cardiovascular system, and skin cannot be neglected. Generally, the expression of DMEs in extrahepatic tissues is quantitatively lower than that in the liver, but there are a few enzymes such as CYP1A1, CYP1B1, CYP2F1, and CYP2U1 that are more abundant in extrahepatic organs. As many extrahepatic organs are portals for administered drugs, DMEs expressed in these organs can be responsible for significant metabolism, leading to first‐pass effects and lower bioavailability. Extrahepatic DMEs are also involved in bioactivation of prodrugs and formation of reactive metabolites that may interact with cellular components, resulting in organ‐specific toxicity. Activity and expression of extrahepatic DMEs is often altered by coadministered drugs, leading to drug–drug interactions. Expression of DMEs in living beings affected by a host of environmental and genetic factors such as genetic polymorphism, age, gender, pathophysiological conditions, inborn errors in metabolism, food habits, and environmental pollutants, contributing to varied drug effects and idiosyncratic toxicities.
The Significance and Determination of Plasma Protein Binding
Authors: Damre Anagha A. , Iyer Krishna R.
Published: October 2012

Drug protein binding can impact both the pharmacokinetics (absorption, distribution and clearance) and pharmacodynamics (receptor/enzyme interaction) of a drug. Among all the proteins that drugs can potentially bind to, binding to plasma proteins and more specifically to human serum albumin, is of significance. Thus, estimation of plasma protein binding is an important part of characterization of a new chemical entity during its development into a drug. Methods to determine plasma protein binding can be broadly divided into methods that either involve or obviate the need for prior separation of protein‐bound and unbound drug. Methods requiring no separation of bound and unbound drug include surface plasmon resonance, capillary electrophoresis, NMR, fluorescence spectroscopy, etc., while equilibrium dialysis, ultracentrifugation, ultrafiltration, microdialysis, involve pre‐separation of bound and free drug for the determination of free fraction of the drug. Some of the methods are amenable to automation and high throughput requirements of drug discovery, but equilibrium dialysis is still considered the ‘gold standard’ for estimation of drug protein binding.
Influence of Changes in Physiology, Transporters, and Enzyme Expression on Disposition and Metabolism of Drugs during Pregnancy and Clinical Implications
Authors: Jhajra Shalu , Singh Saranjit , Holm Karsten A. , Faqi Ali Said , Sahi Jasminder
Published: October 2012

Safe and effective administration of drugs during pregnancy is a challenge due to physiological changes in the mother and limited development of the mechanisms of metabolism of xenobiotics in the fetus. In particular, concentrations of transporters such as PgP, BCRP, MRP3, OCT3, and OCTN1 change in the mother's placenta and fetal tissues with advancing gestation, confounding standard therapies. Drug‐metabolizing enzymes in the placenta and developing fetus differ from those in the liver of the mother. For example, CYP3A7 is the predominant CYP3A isoform in the fetus, while CYP3A4 is predominant in adults. These isoforms have different substrates and kinetics, and thus, challenges to the fetus can be very different. Hence, there is a need for selectivity in administration of drugs and for titrating the dose to maintain efficacy and/or minimize side effects during pregnancy. This is particularly important for drugs with a narrow therapeutic window or those with marked pharmacologic or toxicological outcomes, and also for drugs that are metabolized predominantly by a single enzyme or transporter. Before initiating any new drug regimen during pregnancy, there is the need for systemic monitoring of plasma concentrations for exposure, especially during the initial days of therapy. It is anticipated that with the advancement of understanding of drug metabolism and transport in the placenta and fetus, the potential for making early predictions with respect to effect and tolerance of drugs may be possible, resulting in safer drug therapies for both pregnant mothers and fetus.
When and How to Apply
ADMET
Principles to Drug Discovery and Development
Authors: Smith Dennis A.
Published: October 2012

Absorption, Distribution, Metabolism and Toxicity screening data is now a routine part of drug discovery. Although similar screening systems are providing structure activity relationships (SAR) to projects throughout the world both in industry and academica, the use of the data is not constant. This chapter reviews the various screens and puts the output of the screens into context. Examples of misused screening data are exemplified by protein binding. Many projects try to optimise molecules to provide a higher free fraction based on static
in vitro
experiments. This is scientifically wrong sine unbound plasma concentrations for oral drugs are controlled by intrinsic clearance, data which is provided by completely different screens. The data from screens for intrinsic clearance may themselves be compromised by lack of correction for reagent binding. The chapter provides a framework for designing screening strategies which include ADMET and list important criteria to be considered in defining probabilities of project success.
Applications Using C
aco
‐2 and
TC
7 Cells for Drug Metabolism Studies
Authors: Ferrec Eric Le , Fardel Olivier
Published: October 2012

The purpose of this chapter is the description of cell culture model most used for the study of intestinal passage. After a brief description of intestinal metabolism, the advantages and disadvantages of the caco‐2 model and an example of protocol are discussed. The use of this cellular the model requires precision. These pages are therefore intended to assist a new user in the development of this model in the laboratory.
Triple Quadrupole and Quadrupole Ion Trap Mass Spectrometers
Authors: Ridgeway Mark E. , Glish Gary L.
Published: October 2012

Mass spectrometers based on ion separation using electrodynamic quadrupolar fields have been dominant in the evolution of the field of mass spectrometry. This chapter discusses triple quadrupole mass spectrometers and quadrupole ion trap mass spectrometers, two of the most important and commercially successful instruments in the history of mass spectrometry. An overview of the principles of operation is discussed in terms of the Mathieu stability diagram, a well‐known graphical representation to determine whether ions will have stable or unstable trajectories in a radio frequency (RF) electric field. A brief introduction of tandem mass spectrometry (MS/MS) is also presented. After the general introduction, each type of instrument is discussed individually. A brief historical background is provided for each type of instrument. Finally, there is an overview of the wide array of methods to perform MS/MS experiments.
Current and Future Tools for Predicting Clinical Drug–Drug Interactions
Authors: Bullock Peter L. , Trubetskoy Olga V.
Published: October 2012

In this chapter we describe mechanisms of DDIs in different segments of clinical populations focusing on PK‐based, clinically significant DDIs, and provide information and discuss availablein vitroanalytical tools, assays and platforms to assess and predict possible DDIs in humans at the different stages of drug development process. We analyze and discuss successes and limitation of current approaches including future developments and modern technological advances of the field.
Mechanical Alloying of β‐Type Ti–Nb for Biomedical Applications
Authors: Zhuravleva Ksenia , Scudino Sergio , Khoshkhoo Mohsen Samadi , Gebert Annett , Calin Mariana , Schultz Ludwig , Eckert Jürgen
Published: October 2012

β‐Type Ti–Nb powders which are needed as precursors for porous implant materials were produced by mechanical alloying of elemental powders. The effect of different fractions of the inorganic milling agent NaCl on the phase reactions during the milling process was investigated by means of X‐ray diffraction and scanning and transmission electron microscopy. It was demonstrated, that addition of ≥2 wt% NaCl during continuous ball milling is efficient for establishing a nanostructured β‐phase alloy and for the achievement of high powder yield.
Cytokine responses in relation to age, gender, body mass index, Mycobacterium tuberculosis infection, and otitis media among inuit in greenland
Authors: Nielsen Nina O. , Soborg Bolette , Børresen Malene , Andersson Mikael , Koch Anders
Published: October 2012

Objectives:

To evaluate the cytokine response pattern in Inuit in Greenland in relation to age, gender, body mass index (BMI), Mycobacterium tuberculosis infection (MTI), and otitis media (OM) to assess whether Inuit may have signs of impaired immune responsiveness to infection.

Methods:

A cross‐sectional health assessment was conducted among inhabitants of Maniitsoq, West Greenland, in 2009, and several health outcomes were measured. The prevalence of MTI, overweight, and obesity was assessed among 263 school children and 137 adults, and OM was assessed among the children. Cytokine responses were measured in whole blood cultures after stimulation with phytohemagglutinin or purified protein derivative (PPD). Associations between cytokine concentrations, age, gender, BMI, MTI, and OM were estimated by linear regression.

Results:

Adults had generally higher cytokine concentrations than children. Children with MTI had 2.7 times higher interleukin (IL)‐10 concentrations than those without (P = 0.01), and girls had 80% higher IL‐10 than boys (P < 0.01) after phytohemagglutinin stimulation. Interferon (IFN)γ and tumor necrosis factor (TNF) concentrations were strongly elevated among children (PIFNγ < 0.001 and PTNF < 0.001) and adults (PIFNγ < 0.001 and PTNF <0.01) with MTI compared to those without after PPD stimulation. Adult women had significantly lower IFNγ (P = 0.03) and TNF (P = 0.04) concentrations than men. TNF was positively correlated with BMI in children (P = 0.01), and IL‐10 was positively correlated with BMI in adults (P = 0.0004) after PPD stimulation.

Conclusion:

We found cytokine patterns similar to those reported from other immune competent study populations. Therefore, the study does not support the suggestion that Inuit may have impaired immune reactivity to infection. Am. J. Hum. Biol., 2013. © 2012Wiley Periodicals, Inc.
Paternal age at birth and the risk of obesity in young adulthood: A register‐based birth cohort study of norwegian males
Authors: Eriksen Willy , Sundet Jon M. , Tambs Kristian
Published: October 2012

Objectives:

The aim of this study was to determine the relationship between paternal age at birth and the risk of obesity in young adulthood.

Methods:

Data from the medical birth register of Norway were linked with register data from the Norwegian National Conscript Service and the national statistics agency, Statistics Norway. This study used the data on 346,609 registered males who were born at term in single birth without physical anomalies during 1967–1984 and who were examined at the time of the mandatory military conscription (age 18–20 years). The relationship between paternal age at birth and the occurrence of obesity (body mass index (BMI) ≥ 30.0 kg/m2) at conscription was examined using a multinomial logistic regression analysis with BMI < 25.0 kg/m2 as the reference outcome category.

Results:

The relative risk of obesity at conscription increased linearly with increasing paternal age at birth but did not increase (P = 0.52) with maternal age at birth. Men born when their fathers were 50 years or older had a 55% (95% confidence interval (CI): 14%, 110%) higher relative risk of obesity than men born when their fathers were younger than 20 years of age, after adjustment for age at conscription, birth order, birth year, maternal age at birth, the mother's total number of children, and maternal and paternal education levels.

Conclusions:

The risk of obesity in young Norwegian men increases with advancing paternal age at birth but does not increase with advancing maternal age at birth. Am. J. Hum. Biol., 2013. © 2012Wiley Periodicals, Inc.
A three‐dimensional analysis of bilateral directional asymmetry in the human clavicle
Authors: Abdel Fatah Emam ElHak , Shirley Natalie R. , Mahfouz Mohamed R. , Auerbach Benjamin M.
Published: October 2012

This study presents a novel three‐dimensional analysis using statistical atlases and automated measurements to assess diaphyseal morphology of the clavicle and its relationship to muscle asymmetry. A sample of 505 individuals (285 males, 220 females) from the William McCormick Clavicle Collection was CT scanned, segmented, and added to a statistical bone atlas that captures correspondence between homologous points on the bone surfaces. Muscle attachment sites were localized on the atlas and then propagated across the entire population. Cross‐sectional contours were extracted at 5% increments along the entire bone, as well as at muscle attachment sites and the clavicle waist; maximum and minimum dimensions of each cross‐sectional contour were calculated. In addition, the entire three‐dimensional surface was examined for asymmetry by analyzing the magnitude and directional differences between homologous points across all bone surfaces in the dataset. The results confirm the existing studies on clavicle asymmetry, namely that the left clavicle is longer than the right, but the right is more robust than the left. However, the patterns of asymmetry are sexually dimorphic. Males are significantly asymmetric in all dimensions and at muscle and ligament attachment sites (P < 0.05), whereas female asymmetry is more variable. We hypothesize that this is related to absolute and relative differences in male muscle strength compared to females. However, an area with no muscle attachments on the posterior midshaft was significantly asymmetric in both sexes. We suggest that this is a curvature difference caused by opposing muscle actions at the medial and lateral ends of the bone. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.
Synthesis of 2‐aminomethylpiperidine ruthenium(II) phosphine complexes and their applications in transfer hydrogenation of aryl ketones
Authors: Türkmen Hayati
Published: October 2012

The complex trans,cis‐[RuCl2(PPh3)2(ampi)] (2) was prepared by reaction of RuCl2(PPh3)3 with 2‐aminomethylpiperidine(ampi) (1). [RuCl2(PPh2(CH2)nPPh2)(ampi) (n = 3, 4, 5)] (3–5) were synthesized by displacement of two PPh3 with chelating phosphine ligands. All complexes (2–5) were characterized by 1 H, 13C, 31P NMR, IR and UV‐visible spectroscopy and elemental analysis. They were found to be efficient catalysts for transfer hydrogen reactions. Copyright © 2012 John Wiley & Sons, Ltd.
Measurement of concentration profiles using confocal Raman spectroscopy in multicomponent polymeric coatings—model validation
Authors: Arya Raj Kumar , Vinjamur Madhu
Published: October 2012

Concentrations of the solvents were measured using confocal laser Raman Spectroscopy for two ternary systems, poly(styrene)—tetrahydrofuran—p‐xylene and poly(methyl methacrylate)—ethylbenzene—tetrahydrofuran, during drying at room temperature. The concentrations were compared with predictions of drying models, which utilize several existing theories for mutual diffusion coefficients for polymer solvent systems. Of the nine free volume parameters required to predict diffusion coefficients of binary systems, four for each of the four pairs studied here were estimated as suggested by the literature. Estimation was done by minimizing the difference between predictions of the model and experimental weight loss data for each binary pair. It is found that the predictions of the models which include cross term diffusion coefficients are in better agreement with measured concentrations than those which ignore the cross terms. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Heterologous Expression and Structural Characterisation of a Pyrazinone Natural Product Assembly Line
Authors: Wyatt Morgan A. , Mok M. C. Y. , Junop Murray , Magarvey Nathan A.
Published: October 2012

Through a number of strategies nonribosomal peptide assembly lines give rise to a metabolic diversity not possible by ribosomal synthesis. One distinction within nonribosomal assembly is that products are elaborated on an enzyme‐tethered substrate, and their release is enzyme catalysed. Reductive release by NAD(P)H‐dependent catalysts is one observed nonribosomal termination and release strategy. Here we probed the selectivity of a terminal reductase domain by using a full‐length heterologously expressed nonribosomal peptide synthetase for the dipeptide aureusimine and were able to generate 17 new analogues. Further, we generated an X‐ray structure of aureusimine terminal reductase to gain insight into the structural details associated with this enzymatic domain.
Referenced Dual Pressure‐ and Temperature‐Sensitive Paint for Digital Color Camera Read Out
Authors: Fischer Lorenz H. , Karakus Cüneyt , Meier Robert J. , Risch Nikolaus , Wolfbeis Otto S. , Holder Elisabeth , Schäferling Michael
Published: October 2012

The first fluorescent material for the referenced simultaneous RGB (red green blue) imaging of barometric pressure (oxygen partial pressure) and temperature is presented. This sensitive coating consists of two platinum(II) complexes as indicators and a reference dye, each of which is incorporated in appropriate polymer nanoparticles. These particles are dispersed in a polyurethane hydrogel and spread onto a solid support. The emission of the (oxygen) pressure indicator, PtTFPP, matches the red channel of a RGB color camera, whilst the emission of the temperature indicator [PtII(Br‐thq)(acac)] matches the green channel. The reference dye, 9,10‐diphenylanthracene, emits in the blue channel. In contrast to other dual‐sensitive materials, this new coating allows for the simultaneous imaging of both indicator signals, as well as the reference signal, in one RGB color picture without having to separate the signals with additional optical filters. All of these dyes are excitable with a 405 nm light‐emitting diode (LED). With this new composite material, barometric pressure can be determined with a resolution of 22 mbar; the temperature can be determined with a resolution of 4.3 °C.
Jahn–Teller Effect in Circulenes: X‐ray Diffraction Study of Coronene and Corannulene Radical Anions
Authors: Filatov Alexander S. , Sumner Natalie J. , Spisak Sarah N. , Zabula Alexander V. , Rogachev Andrey Yu. , Petrukhina Marina A.
Published: October 2012

Single‐crystal X‐ray diffraction studies of two polyaromatic radical anions crystallized as sodium salts, namely [Na(DME)3]+[C20H10−] (1) and [Na(DME)3]+[C24H12−] (2) are reported. This allowed the first structural evaluation of Jahn–Teller (JT) effects for monoreduced circulenes and a comparison between bowl‐shaped corannulene and planar coronene. The Cs and D2h symmetrical distortions are found to fit the experimental data for C20H10.− and C24H12.−, respectively. The continuous symmetry measure (CSM) analysis was carried out to provide a quantitative measure of the JT distortions in 1 and 2. In addition, the X‐ray crystallographic results were fully supported by DFT calculations.
Highly Regioselective Preparation of Heteroaryl–Magnesium Reagents by Using a Br/Mg Exchange
Authors: Sämann Christoph , Haag Benjamin , Knochel Paul
Published: October 2012

Disubstituted thienyl‐, furyl‐ and pyridylmagnesium derivatives are regioselectively prepared from a Br/Mg exchange of the corresponding dibromo compounds by using either iPrMgCl⋅LiCl or hindered arylmagnesium reagents, such as isitylmagnesium bromide⋅lithium chloride (isityl=2,4,6‐triisopropyl‐phenyl) complexed with a diamine ligand, in difficult cases. The selective functionalisations of these heterocyclic scaffolds by using Negishi cross‐coupling reactions, acylations or addition to aldehydes were readily achieved.
Exceptional Blueshifted and Enhanced Aggregation‐Induced Emission of Conjugated Asymmetric Triazines and Their Applications in Superamplified Detection of Explosives
Authors: An Zhong‐Fu , Zheng Chao , Chen Run‐Feng , Yin Jun , Xiao Jian‐Jian , Shi Hui‐Fang , Tao Ye , Qian Yan , Huang Wei
Published: October 2012

A novel conjugated asymmetric donor–acceptor (CADA) strategy for preventing the redshift in photoluminescence, as well as preserving the merits of donor–acceptor architectures, was proposed and demonstrated for two triazine derivatives, which showed highly efficient, narrow, and blueshifted ultraviolet light emission in solid films along with special aggregation‐induced emission behavior. A mechanism of aggregation‐induced locally excited‐state emission by suppressing the twisted intramolecular charge‐transfer emission for the spectacular optoelectronic phenomena of these CADA molecules was suggested on the basis of both experimental measurements and theoretical calculations. By taking advantage of this special CADA architecture, fluorescent probes based on aggregates of conjugated asymmetric triazines in THF/water for the detection of explosives show superamplified detection of picric acid with high quenching constants (>1.0×107 M−1) and a low detection limit of 15 ppb.