bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of Dementia: Focus on Lifestyle
Authors: Polidori Maria Cristina , Nelles Gereon , Pientka Ludger
Published: June 2010

The objective of this paper is to summarize current knowledge on the possible advantages of lifestyle interventions, with particular attention to physical fitness, cognitive activity, leisure and social activity as well as nutrition. There is a large amount of published papers providing partial evidence and asserting the need for immediate, appropriate preventive lifestyle measures against dementia and AD development. Nevertheless, there are currently great difficulties in drafting effective guidelines in this field. This depends mainly upon lack of randomized controlled trials assessing benefits versus risks of particular lifestyle interventions strategies. However, due to the rapid increase of dementia burden, lifestyle factors and their amelioration should be already made part of decision making in light of their health-maintaining effects while awaiting for results of well-designed large prospective cohort studies in dementia.
The Tsim Tsoum Approaches for Prevention of Cardiovascular Disease
Authors: Singh R. B. , DeMeester Fabien , Wilczynska Agnieska
Published: June 2010

The Tsim Tsoum Concept means that humans evolved on a diet in which nature recommends to ingest fatty acids in a balanced ratio (polyunsaturated(P) : saturated(S) =w-6 : w-3 = 1 : 1)as part of dietary lipid pattern where monounsaturated fatty acids(MUFA) is the major fatty acid(P : M : S = 1 : 6 : 1) in the background of other dietary factors; antioxidants, vitamins, minerals and fiber as well as physical activity and low mental stress. Several hundred years ago, our diet included natural foods; fruits, vegetables, green vegetables, seeds, eggs and honey. Fish, and wild meat were also available to pre-agricultural humans which shaped modern human genetic nutritional requirement. Cereal grains (refined), and vegetable oils that are rich in w-6 fatty acids are relatively recent addition to the human diet that represent dramatic departure from those foods to which we are adapted. Excess of linoleic acid, trans fatty acids (TFA), saturated and total fat as well as refined starches and sugar are proinflammatory. Low dietary MUFA and n-3 fatty acids and other long chain polyunsarurated fatty acids (LCPUFA) are important in the pathogenesis of metabolic syndrome. Increased sympathetic activity with greater secretion of neurotransmitters in conjunction of underlying long chain PUFA deficiency, and excess of proinflammatory nutrients, may damage the neurons via proinflammatory cytokines, in the ventromedial hypothalamus and insulin receptors in the brain.Since, 30–50% of the fatty acids in the brain are LCPUFA, especially omega-3 fatty acids, which are incorporated in the cell membrane phospholipids, it is possible that their supplementation may be protective.Blood lipid composition does reflect one's health status: (a) circulating serum lipoproteins and their ratio provide information on their atherogenicity to blood vessels and (b) circulating plasma fatty acids, such as w-6/w-3 fatty acid ratio, give indication on proinflammatory status of blood vessels, cardiomyocytes, liver cells and neurones; (a) and (b) are phenotype-related and depend on genetic, environmental and developmental factors. As such, they appear as universal markers for holistic health and these may be important in the pathogenesis of cardiovascular diseases and cancer, which is the main consideration of Tsim Tsoum concept.
The –SH Protection Method for Determining Accurate Kd Values for Enzyme-Coenzyme Complexes of NAD+-Dependent Glutamate Dehydrogenase and Engineered Mutants: Evidence for Nonproductive NADPH Complexes
Authors: Griffin Joanna , Engel Paul C.
Published: June 2010

Inactivation rates have been measured for clostridial glutamate dehydrogenase and several engineered mutants at various DTNB concentrations. Analysis of rate constants allowed determination of Kd for each non-covalent enzyme-DTNB complex and the rate constant for reaction to form the inactive enzyme-thionitrobenzoate adduct. Both parameters are sensitive to the mutations F238S, P262S, the double mutation F238S/P262S, and D263K, all in the coenzyme binding site. Study of the effects of NAD+, NADH and NADPH at various concentrations in protecting against inactivation by 200 μM DTNB allowed determination of Kd values for binding of these coenzymes to each protein, yielding surprising results. The mutations were originally devised to lessen discrimination against the disfavoured coenzyme NADP(H), and activity measurements showed this was achieved. However, the Kd determinations indicated that, although Kd values for NAD+ and NADH were increased considerably, Kd for NADPH was increased even more than for NADH, so that discrimination against binding of NADPH was not decreased. This apparent contradiction can only be explained if NADPH has a nonproductive binding mode that is not weakened by the mutations, and a catalytically productive mode that, though strengthened, is masked by the nonproductive binding. Awareness of the latter is important in planning further mutagenesis.
Surfactants in cloud droplet activation: mixed organic-inorganic particles
Authors: Prisle N. L. , Raatikainen T. , Laaksonen A. , Bilde M.
Published: June 2010

Abstract. Organic compounds with surfactant properties are commonly found in atmospheric aerosol particles. Surface activity can significantly influence the cloud droplet forming ability of these particles. We have studied the cloud droplet formation by two-component particles comprising one of the organic surfactants sodium octanoate, sodium decanoate, sodium dodecanoate, and sodium dodecyl sulfate, mixed with sodium chloride. Critical supersaturations were measured with a static diffusion cloud condensation nucleus counter (Wyoming CCNC-100B). Results were modeled from Köhler theory applying three different representations of surfactant properties in terms of surfactant surface partitioning and reduced droplet surface tension. We here confirm previous results for single-component organic surfactant particles, that experimental critical supersaturations are greatly underpredicted, if reduced surface tension is used while ignoring the effects of surface partitioning in droplets. Furthermore, disregarding surfactant properties by ignoring surface partitioning and assuming the constant surface tension of pure water can also lead to significant underpredictions of experimental critical supersaturations. For the mixed particles comprising less than 50% by mass of surfactant, this approach however still provides a good description of the observed droplet activation. A comprehensive account for surfactant properties, including both surface tension reduction and effects of surface partitioning in activating droplets, generally predicts experimental critical supersaturations well.
Molecular hydrogen (H2) emissions and their isotopic signatures (H/D) from a motor vehicle: implications on atmospheric H2
Authors: Vollmer M. K. , Walter S. , Bond S. W. , Soltic P. , Röckmann T.
Published: June 2010

Abstract. Molecular hydrogen (H2), its isotopic signature (deuterium/hydrogen, δD), carbon monoxide (CO), and other compounds were studied in the exhaust of a passenger car engine fuelled with gasoline or methane and run under variable air-fuel ratios and operating modes. H2 and CO concentrations were largely reduced downstream of the three-way catalytic converter (TWC) compared to levels upstream, and showed a strong dependence on the air-fuel ratio (expressed as lambda, λ). The isotopic composition of H2 ranged from δD = −140‰ to δD = −195‰ upstream of the TWC but these values decreased to −270‰ to −370‰ after passing through the TWC. Post-TWC δD values for the fuel-rich range showed a strong dependence on TWC temperature with more negative δD for lower temperatures. These effects are attributed to a rapid temperature-dependent H-D isotope equilibration between H2 and water (H2O). In addition, post TWC δD in H2 showed a strong dependence on the fraction of removed H2, suggesting isotopic enrichment during catalytic removal of H2 with enrichment factors (ε) ranging from −39.8‰ to −15.5‰ depending on the operating mode. Our results imply that there may be considerable variability in real-world δD emissions from vehicle exhaust, which may mainly depend on TWC technology and exhaust temperature regime. This variability is suggestive of a δD from traffic that varies over time, by season, and by geographical location. An earlier-derived integrated pure (end-member) δD from anthropogenic activities of −270‰ (Rahn et al., 2002) can be explained as a mixture of mainly vehicle emissions from cold starts and fully functional TWCs, but enhanced δD values by >50‰ are likely for regions where TWC technology is not fully implemented. Our results also suggest that a full hydrogen isotope analysis on fuel and exhaust gas may greatly aid at understanding process-level reactions in the exhaust gas, in particular in the TWC.
Ozone variability and halogen oxidation within the Arctic and sub-Arctic springtime boundary layer
Authors: Gilman J. B. , Burkhart J. F. , Lerner B. M. , Williams E. J. , Kuster W. C. , Goldan P. D. , Murphy P. C. , Warneke C. , Fowler C. , Montzka S. A. , Miller B. R. , Miller L. , Oltmans S. J. , Ryerson T. B. , Cooper O. R. , Stohl A. , de Gouw J. A.
Published: June 2010

Abstract. The influence of halogen oxidation on the variabilities of ozone (O3) and volatile organic compounds (VOCs) within the Arctic and sub-Arctic atmospheric boundary layer was investigated using field measurements from multiple campaigns conducted in March and April 2008 as part of the POLARCAT project. For the ship-based measurements, a high degree of correlation (r=0.98 for 544 data points collected north of 68° N) was observed between the acetylene to benzene ratio, used as a marker for halogen oxidation, and O3 signifying the vast influence of bromine oxidation throughout the ice-free regions of the North Atlantic. Concurrent airborne and ground-based measurements in the Alaskan Arctic substantiated this correlation and were used to demonstrate that halogen oxidation influenced O3 variability throughout the Arctic boundary layer during these springtime studies. Measurements aboard the R/V "Knorr" in the North Atlantic and Arctic Oceans provided a unique view of the transport of O3-poor air masses from the Arctic Basin to latitudes as far south as 52° N. FLEXPART, a Lagrangian transport model, was used to quantitatively determine the exposure of air masses encountered by the ship to first-year ice (FYI), multi-year ice (MYI), and total ICE (FYI+MYI). O3 anti-correlated with the modeled total ICE tracer (r=−0.86) indicating that up to 73% of the O3 variability measured in the Arctic marine boundary layer could be related to sea ice exposure.
A refinement of the emission data for Kola Peninsula based on inverse dispersion modelling
Authors: Prank M. , Sofiev M. , Denier van der Gon H. A. C. , Kaasik M. , Ruuskanen T. M. , Kukkonen J.
Published: June 2010

Abstract. The study reviews the emission estimates of sulphur oxides (SOx) and primary particulate matter (PM) from the major industrial sources of Kola Peninsula. Analysis of the disagreements between the existing emission inventories for the Kola region combined with forward and inverse ensemble dispersion modelling, analysis of observation time-series and model-measurement comparison showed that the emission of the Nikel non-ferrous metallurgy plant was missing from the EMEP inventory, as well as from some others, being in some cases misplaced or mis-attributed to other sources of the region. A more consistent inventory of the anthropogenic emissions of SOx and PM has been compiled for the peninsula, compared with the existing estimates and verified by means of dispersion modelling. In particular, the SILAM model simulations for 2003 and 2006 with the revised emission data showed much lower bias – up to 6 times for the most-affected sites – for SO2 with regard to the measured concentrations of 8 Finnish and Norwegian observational stations in the region. Temporal correlation improved moderately (10–20%) but homogeneously over Lapland. The study demonstrates the value of a combined usage of forward and inverse ensemble modelling for source apportionment in case of limited observational data.
Differential optical absorption spectroscopy (DOAS) and air mass factor concept for a multiply scattering vertically inhomogeneous medium: theoretical consideration
Authors: Rozanov V. V. , Rozanov A. V.
Published: June 2010

Abstract. The Differential Optical Absorption Spectroscopy (DOAS) technique is widely used to retrieve amounts of atmospheric species from measurements of the direct solar light transmitted through the Earth's atmosphere as well as of the solar light scattered in the atmosphere or reflected from the Earth's surface. For the transmitted direct solar light the theoretical basis of the DOAS technique represented by the Beer-Lambert law is well studied. In contrast, scarcely investigated is the theoretical basis and validity range of the DOAS method for those cases where the contribution of the multiple scattering processes is not negligible. Our study is intended to fill this gap by means of a theoretical investigation of the applicability of the DOAS technique for the retrieval of amounts of atmospheric species from observations of the scattered solar light with a non-negligible contribution of the multiple scattering. Starting from the expansion of the intensity logarithm in the functional Taylor series we formulate the general form of the DOAS equation. The thereby introduced variational derivative of the intensity logarithm with respect to the variation of the gaseous absorption coefficient, which is often referred to as the weighting function, is demonstrated to be closely related to the air mass factor. Employing some approximations we show that the general DOAS equation can be rewritten in the form of the weighting function (WFDOAS), the modified (MDOAS), and the standard DOAS equations. For each of these forms a specific equation for the air mass factor follows which, in general, is not suitable for other forms of the DOAS equation. Furthermore, the validity range of the standard DOAS equation is quantitatively investigated using a suggested criterion of a weak absorption. The results presented in this study are intended to provide a basis for a better understanding of the applicability range of different forms of the DOAS equation as well as of the relationship between the air mass factor and the weighting function. To facilitate the understanding of the paper content for unexperienced reader we start our discussion considering in detail the standard DOAS technique applied to the observations of the direct solar light transmitted through the Earth's atmosphere.
Aerosol Optical Depth measurements at 340 nm with a Brewer spectrophotometer and comparison with Cimel observations at Uccle, Belgium
Authors: De Bock V. , De Backer H. , Mangold A. , Delcloo A.
Published: June 2010

Abstract. The Langley Plot Method (LPM) is adapted for the retrieval of Aerosol Optical Depth (AOD) values at 340 nm from Brewer#178 sun scan measurements between 335 and 345 nm (convoluted with the band pass function of the Cimel filter at 340 nm). The use of sun scans instead of direct sun measurements simplifies the comparison of the AOD values with quasi-simultaneous Cimel values. Also, the intensities are larger at 340 nm due to lower ozone absorption, thus improving the signal to noise ratio. For the selection of the cloudless days, a new set of criteria is proposed. With the new method, individual clear sky AOD values, for which the selection criteria are also presented in this article, are calculated for a period from September 2006 to December 2009. These values are then compared to quasi-simultaneous Cimel measurements, showing a very good linear agreement (the correlation coefficient, the slope and the intercept are, respectively 0.960, 0.992 and 0.005), which proves that good quality observations can be obtained from Brewer sun scan measurements at 340 nm. The seasonal and monthly variability of the Brewer AODs at Uccle are consistent with other studies. The highest values can be observed in summer and spring. More than 50% of the winter AODs are lower than 0.3 whereas in summer, more than 50% of the values are larger than 0.5. On a monthly scale, the lowest AOD are observed in December and the highest values occur in June and April. No clear weekly cycle is observed for Uccle.
Runoff and mass-balance simulations from the Greenland Ice Sheet at Kangerlussuaq (Søndre Strømfjord) in a 30-year perspective, 1979–2008
Authors: Mernild S. H. , Liston G. E. , Steffen K. , van den Broeke M. , Hasholt B.
Published: June 2010

Abstract. This study provides insights into surface mass-balance (SMB) and runoff exiting the Watson River drainage basin, Kangerlussuaq, West Greenland during a 30 year period (1978/1979–2007/2008) when the climate experienced increasing temperatures and precipitation. The 30-year simulations quantify the terrestrial freshwater output from part of the Greenland Ice Sheet (GrIS) and the land between the GrIS and the ocean, in the context of global warming and increasing GrIS surface melt. We used a snow-evolution modeling system (SnowModel) to simulate the winter accumulation and summer ablation processes, including runoff and SMB, of the ice sheet: indicating that the simulated equilibrium line altitude (ELA) was in accordance with independent observations. To a large extent, the SMB fluctuations could be explained by changes in net precipitation (precipitation minus evaporation and sublimation), with 8 out of 30 years having negative SMB, mainly because of relatively low annual net precipitation. The overall trend in net precipitation and runoff increased significantly, while SMB increased insignificantly throughout the simulation period, leading to enhanced precipitation of 0.59 km3 w.eq. (or ~60%), runoff of 0.43 km3 w.eq. (or ~55%), and SMB of 0.16 km3 w.eq. (or ~85%). Runoff rose on average from 0.80 km3 w.eq. in 1978/1979 to 1.23 km3 w.eq. in 2007/2008. The GrIS satellite-derived melt-extent increased significantly, and the melting intensification occurred simultaneously with the increase in local Kangerlussuaq runoff, indicating that satellite data can be used as a proxy (r2=0.64) for runoff from the Kangerlussuaq drainage area.
Oil Shale
Authors: Weiss Hans‐Jürgen , Lisboa Antonio Carlos Luz
Published: June 2010

The article contains sections titled:

1.

Introduction

2.

Origin and Properties of Oil Shale

2.1.

Origin, Stratification

2.2.

Physical Properties

2.3.

Chemical Composition

3.

World Resources and Deposits

3.1.

Europe

3.1.1.

Western Europe

3.1.2.

Eastern Europe

3.2.

America

3.3.

Asia

3.4.

Africa

3.5.

Australia and New Zealand

4.

Exploitation

5.

Mining Methods

5.1.

Underground Mining

5.2.

Aboveground Mining

6.

Shale Preparation

7.

Pyrolysis

7.1.

Definition and Kinetics

7.2.

Aboveground Retorting Processes

7.2.1.

Class 1 (Indirectly Gas‐Heated) Retorts

7.2.2.

Class 2 (Directly Gas‐Heated) Retorts

7.2.3.

Class 3 (Directly Solids‐Heated) Retorts

7.3.

In Situ Processing of Oil Shale

8.

Combustion

9.

Gasification

10.

Properties and Uses of the Products

11.

Outlook
Plant Growth Regulators
Authors: Rademacher Wilhelm , Brahm Lutz
Published: June 2010

This article contains sections titled:1.Introduction2.Classes of “True” Plant Growth Regulators2.1.Compounds Related to Auxins2.1.1.Natural and Synthetic Auxins2.1.1.1.Indol‐3‐ylacetic Acid (IAA)2.1.1.2.Indol‐3‐ylbutyric Acid (IBA)2.1.1.3.1‐Naphthylacetic Acid (NAA)2.1.1.4.2‐(1‐Naphthyl)acetamide (NAAm)2.1.1.5.Carbaryl2.1.2.Inhibitors of Auxin Transport2.1.2.1.N‐m‐Tolylphthalamic Acid2.1.2.2.Cyclanilide2.2.Compounds Related to Gibberellins2.2.1.Naturally‐Occurring Gibberellins and Compounds with Gibberellin‐Like Activity2.2.1.1.Gibberellic Acid = Gibberellin A3(GA3)2.2.1.2.Mixture of Gibberellin A4with Gibberellin A7(GA4/7)2.2.1.3.AC 94,3772.2.2.Inhibitors of Gibberellin Biosynthesis2.2.2.1.Chlormequat Chloride‐Chlorocholine Chloride (CCC)2.2.2.2.Mepiquat Chloride2.2.2.3.Flurprimidol2.2.2.4.Inabenfide2.2.2.5.Paclobutrazol2.2.2.6.Uniconazole2.2.2.7.Daminozide2.2.2.8.Trinexapac‐ethyl2.2.2.9.Prohexadione (Calcium Salt)2.3.Cytokinins2.3.1.6‐Benzylaminopurine (6‐BA, BAP)2.3.2.Thidiazuron (TDZ)2.3.3.Forchlorfenuron (CPPU)2.4.Abscisic Acid (ABA)2.4.1.(S)‐Abscisic Acid (S‐ABA)2.5.Compounds Related to Ethylene2.5.1.Ethylene, Ethylene‐Removing and Ethylene‐Releasing Compounds2.5.1.1.Ethephon2.5.2.Inhibitors of Ethylene Biosynthesis2.5.2.1.Aviglycin (Hydrochloride) (AVG)2.5.3.Inhibitors of Ethylene Action2.5.3.1.1‐Methylcyclopropene (1‐MCP)3.Compounds with Effects Similar to Plant Growth Regulators3.1.Compounds Causing Subtle Phytotoxicity3.1.1.Hydrogen Cyanamide3.1.2.Mefluidide3.1.3.Maleic Hydrazide (Potassium Salt)3.1.4.Chlorpropham (CIPC)3.1.5.Dikegulac (Sodium Salt)3.2.Distinct Fungicides, Insecticides and Herbicides3.2.1.Pyraclostrobin4.Outlook/Conclusions
Applications of High Performance Ion‐Exchange Chromatography in the Pharmaceutical Industry
Authors: Workentine Matthew L. , Tran Vy A. , Turner Raymond J.
Published: June 2010

A variety of analytical chemistry methods are available for analyzing the broad range of compounds utilized in the pharmaceutical industry. In comparison of mass spectrometry and NMR, chromatography is useful technique for chemical analysis and can be done with column, pump, and detector. This article focuses on basic theory and applications of high performance ion‐exchange chromatography (HPIC) in the pharmaceutical industry.
From Concept to the Clinics: Development of Novel Large Molecule Cancer Therapeutics
Authors: Kaur Balveen , Lesinski Gregory B. , Chaudhury Abhik Ray
Published: June 2010

Development of a therapeutic agent is a laborious process commencing with the discovery of a “druggable target” underlying the pathology of a disease. Discovery process is followed by identification of a lead molecule/compound, optimization of the pharmaceutical formulation of the compound, laboratory testing, IND approval, and clinical trials. This article focuses on characterization, pharmaceutical formulation, and clinical studies of bevacizumab (avastin), proteasome inhibitors, interferon‐alpha (IFN‐•), and oncolytic viruses.
Karl Fischer Titration: Determination of Water Content in Pharmaceuticals
Authors: Schoeffski Katrin , Hoffmann Helga
Published: June 2010

Water determination plays an important role in the pharmaceutical analysis. The national pharmacopoeias describe the Karl Fischer titration as a method for water determination. The Karl Fischer titration is based on the reaction from iodine with sulfur dioxide in alcohol in the presence of water. This article focuses on determination of water content in pharmaceuticals by Karl Fischer titration.
EDTATitrations
Authors: Chang Zheng
Published: June 2010

The EDTA titration is based on the stoichiometric formation of water‐soluble metal‐EDTA complex to determine the concentration of the metal ion in aqueous solutions. In comparison of advanced instrumental techniques, the EDTA titration is simple to operate, can produce accurate results for sample with different complexities, and does not require costly instrumentation. This article focuses on basic principles, titration curves, end point detection, titration types, and practical considerations in EDTA titration.
Good Manufacturing Practices—Steps to Improve Quality
Authors: Snyder John E.
Published: June 2010

Current Good Manufacturing Practices (CGMP) has mandated drug manufacturers to follow regulations on the manufacturing process in addition to quality of the end product. CGMP regulations cover aspects of daily operations that are the basis of good business practices. This article focuses on the CGMP regulations and their implication on the business of a pharmaceutical company.
High Performance Liquid Chromatography (HPLC) in the Pharmaceutical Analysis
Authors: Levin Shulamit
Published: June 2010

High Performance Liquid Chromatograhy (HPLC) is the most important analytical technique used during the various stages of drug development and manufacturing. The key to a proper HPLC system operation is the knowledge of the principles of chromatographic process as well as the understanding of the reasons behind the choice of components of the chromatographic system. This article focuses on HPLC theory, its role in drug analysis, and its techniques.
Handbook of Analysis and Pharmaceutical Quality: Nano‐Methods
Authors: Tyner Katherine M.
Published: June 2010

The expansion of nanotechnology in the pharmaceutical industry has opened up a new field of therapy as well as increased the pressure on regulatory bodies for adequate regulation and safety assessment. The impact nanotherapeutics, drug delivery systems, or combination products could affect treatment of disease by enabling targeted delivery. This article provides an overview of the methods typically used to characterize nanomaterials specifically relating to pharmaceutical industry and their relevance to the field.
X‐Ray Fluorescence Spectrometry in Medicine
Authors: Nie Linda
Published: June 2010

X‐ray Fluorescence (XRF) and neutron activation analysis (NAA) are the two main non‐invasive methods for in vivo and in vitro element analysis. XRF is the emission of fluorescent x‐rays from a material that has been bombarded with x‐rays of gamma rays. This article describes XRF technology for in vivo element measurement.
Systems‐Based Approach to Laboratory Compliance with the Current Good Manufacturing Practice (
CGMP
) Regulations
Authors: Bliesner David M.
Published: June 2010

The laboratory control system can be divided into at least seven different sub elements which are required to insure overall compliance with the Current Good Manufacturing Practice (CGMP) regulations. These include: (1) Laboratory Managerial and Administrative Systems, (2) Laboratory Documentation Practices and Standard Operating Procedures, (3) Laboratory Equipment Qualification and Calibration, (4) Laboratory Facilities, (5) Methods Validation, (6) Laboratory Computer Systems, and (7) Laboratory Investigations. This article outlines potential sub elements of the laboratory control system which are required for smooth and compliant laboratory operations of a typical analytical laboratory.
Uses ofX‐Ray Powder Diffraction In the Pharmaceutical Industry
Authors: Ivanisevic Igor , McClurg Richard B. , Schields Paul J.
Published: June 2010

X‐ray diffraction (XRD) has a broad range of applications in various stages of drug development and manufacturing, such as API characterization and identification. API characterization is more commonly applied during drug development while API identification is directed more towards manufacturing, regulatory aspects, and intellectual property. This article focuses on basic principles and experimental procedures of XRD and its application in API characterization and identification.
Water Determination By Karl Fischer Titration
Authors: Margreth Michael , Schlink Regina , Steinbach Alfred
Published: June 2010

A variety of analytical techniques have been used for water determination. These include drying methods and titration methods. In comparison of drying, titration is rapid and can be validated. This article focuses on water determination by Karl Fischer titration.
The Langmuir‐Blodgett Approach to Making Colloidal Photonic Crystals from Silica Spheres
Authors: Bardosova Maria , Pemble Martyn E. , Povey Ian M. , Tredgold Richard H.
Published: June 2010

The area of colloidal photonic crystal research has attracted enormous attention in recent years as a result of the potential of such materials to provide the means of fabricating new or improved photonic devices. As an area where chemistry still predominates over engineering the field is still in its infancy in terms of finding real applications being limited by ease of fabrication, reproducibility and ‘quality’‐ for example the extent to which ordered structures may be prepared over large areas. It is our contention that the Langmuir‐Blodgett assembly method when applied to colloidal particles of silica and perhaps other materials, offers a way of overcoming these issues. To this end the assembly of silica and other particles into colloidal photonic crystals using the Langmuir‐Blodgett (LB) method is described and some of the numerous papers on this topic, which have been published, are reviewed. It is shown that the layer‐by‐layer control of photonic crystal growth afforded by the LB method allows for the fabrication of a range of novel, layered photonic crystals that may not be easily assembled using any other approach. Some of the more interesting of these structures, including so‐called heterostructured photonic crystals comprising of layers of spheres having different diameters are presented and their optical properties described. Finally, we offer our comments as to future applications of this interesting technology.
Darcy's law–based numerical simulation for modeling 3D liquid absorption into porous wicks
Authors: Masoodi Reza , Tan Hua , Pillai Krishna M.
Published: June 2010

Liquid imbibition into polymer wicks, where a clear liquid front can be seen rising during the wicking process, is modeled using the concepts of flow in porous media. The flow of liquid behind the moving liquid front is modeled using the physics of single‐phase flow in a porous medium where the Darcy's law is combined with the continuity equation and a capillary suction pressure is imposed at the liquid front. A novel numerical simulation PORE‐FLOW© based on the finite element/control volume method is proposed to model such imbibitional flows in wicks of complex shapes. A validation of the simulation is obtained by achieving an excellent comparison of its predictions with an experimental result, an analytical solution, and the Washburn equation for the case of wicking against gravity in a cylindrical wick. The simulation is also used to predict a case of two‐dimensional (2D) wicking in the altered cylindrical wicks with two different cross‐sectional areas. Once again an excellent match is obtained with the experimental results, while analytical solutions for the single and double cross‐section cases along with the Washburn equation fail to predict the 2D wicking. Later, some other types of altered wicks with sharp changes in their cross‐sectional areas were analyzed numerically for their wicking behavior. It was observed that the height of liquid front in a vertical wick as a function of time, which is proportional to the history of liquid imbibed, is strongly dependent on the extent of reduction in the wick cross‐sectional area as well as its location vis‐à‐vis the wick entrance. © 2010 American Institute of Chemical Engineers AIChE J, 2011
A dimensionless model for predicting the mass‐transfer area of structured packing
Authors: Tsai Robert E. , Seibert A. Frank , Eldridge R. Bruce , Rochelle Gary T.
Published: June 2010

The mass‐transfer area of nine structured packings was measured in a 0.427 m ID column via absorption of CO2 from air into 0.1 kmol/m3 NaOH. The mass‐transfer area was most strongly related to the specific area (125–500 m2/m3), and liquid load (2.5–75 m3/m2·h). Surface tension (30–72 mN/m) had a weaker but significant effect. Gas velocity (0.6–2.3 m/s), liquid viscosity (1–15 mPa·s), and flow channel configuration had essentially no impact on the mass‐transfer area. Surface texture (embossing) increased the effective area by 10% at most. The ratio of mass‐transfer area to specific area (ae/ap) was correlated within the limits of ±13% for the entire experimental database
${{a_{\rm{e}} } \over {a_{\rm{p}} }}= 1.34 \left[ {\left( {{{\rho _{\rm{L}} } \over \sigma }} \right)g^{1/3} \left( {{Q \over {L_{\rm{p}} }}} \right)^{4/3}} \right]^{\,0.116}$. © 2010 American Institute of Chemical Engineers AIChE J, 2010
A contact‐point based approach for the analysis of reactions among solid particles
Authors: Dalvi Vishal V. , Suresh A. K.
Published: June 2010

The contact‐point framework,1 which replaces the picture of continuous contact between the reactants by contact at a finite number of points, has been proposed as a rational one for treating reactions among particulate solids. However, available models suffer from various drawbacks, the main one being that they do not show the right asymptotic behavior for large number of contact points. A model is presented here, that corrects these deficiencies. The results show that the contact‐point model approaches particle‐continuum behavior whenever the number of contact points exceeds 500. The model predictions have been compared with some data from our previous work on calcia‐alumina system in the temperature range 1,150–1,300°C. The model fits the data well, with the fitted values of diffusivity (of calcia through alumina) being of the order of 10−16 m2/s. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Biosimilar epoetins and other “follow‐on” biologics: Update on the European experiences
Authors: Jelkmann Wolfgang
Published: June 2010

After the patents of biopharmaceuticals have expired, based on specific regulatory approval pathways copied products (“biosimilars” or “follow‐on biologics”) have been launched in the EU. This article summarizes experiences with hematopoietic medicines, namely the epoetins (two biosimilars traded under five different brand names) and the filgrastims (two biosimilars, six brand names). Physicians and pharmacists should be familiar with the legal and pharmacological specialities of biosimilars: The production process can differ from that of the original, clinical indications can be extrapolated, glycoproteins contain varying isoforms, the formulation may differ from the original, and biopharmaceuticals are potentially immunogenic. Only on proof of quality, efficacy and safety, biosimilars are a viable option because of their lower costs. Am. J. Hematol. 2010. © 2010 Wiley‐Liss, Inc.
Unexpectedly low pulse oximetry measurements associated with variant hemoglobins: A systematic review
Authors: Verhovsek Madeleine , Henderson Matthew P.A. , Cox Gerard , Luo Hong‐yuan , Steinberg Martin H. , Chui David H.K.
Published: June 2010

Pulse oximetry estimates arterial blood oxygen saturation based on light absorbance of oxy‐ and deoxy‐hemoglobin at 660 and 940 nm wavelengths. Patients with unexpectedly low SpO2 often undergo cardio‐pulmonary testing to ascertain the cause of their hypoxemia. However, in a subset of patients, a variant hemoglobin is responsible for low SpO2 measurements. The extent of this problem is unclear. We performed a systematic literature review for reports of low SpO2 associated with variant hemoglobins. We also reviewed unpublished cases from an academic hemoglobin diagnostic reference laboratory. Twenty‐five publications and four unpublished cases were identified, representing 45 patients with low SpO2 and confirmed variant hemoglobin. Fifty‐seven family members of patients had confirmed or suspected variant hemoglobin. Three low oxygen affinity variant hemoglobins had concordantly low SpO2 and SaO2. Eleven variant hemoglobins were associated with unexpectedly low SpO2 measurements but normal SaO2. Hemoglobin light absorbance testing was reported in three cases, all of which showed abnormal absorption spectra between 600 and 900 nm. Seven other variant hemoglobins had decreased SpO2, with unreported or uncertain SaO2. Twenty‐one variant hemoglobins were found to be associated with low SpO2. Most variant hemoglobins were associated with spuriously low SpO2. Abnormal absorption spectra explain the discrepancy between SpO2 and SaO2 for some variants. The differential diagnosis of possible variant hemoglobin ought to be considered in asymptomatic patients found to have unexpectedly low SpO2. The correct diagnosis will help to spare patients from unnecessary investigations and anxiety. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
In situ photopolymerization of PEGDA‐protein hydrogels on nanotube surfaces
Authors: Smoak Evan M. , Henricus Marsiyana M. , Banerjee Ipsita A.
Published: June 2010

Peptide nanotubes were used as templates for the growth of poly(ethylene glycol) diacrylate‐based nanoscale hydrogels via photopolymerization. A Rose Bengal di‐amine derivative comprised of a photoactivator and coinitiator within the same molecule was used as the photoinitiator to increase photopolymerization efficiency. The nanotubes were covalently bound to the protein BSA before formation of the hydrogels. We also examined the photopolymerization efficiency in reactions involving nanotubes in the absence of BSA. Although photopolymerization occurred efficiently under both conditions, higher yields of highly crosslinked nanostructures were obtained for the protein bound nanotube‐PEGDA hydrogels. It was observed that the swelling ratios were also dependent upon whether or not BSA was bound to the nanotubes before photopolymerization. The thermal properties of the nanocomposite hydrogels were investigated using differential scanning calorimetry analyses and the morphologies were examined using TEM, SEM, and AFM analyses. Such nanocomposites prepared by low cost, mild methods could be extremely efficient for the in situ preparation of three‐dimensional arrays of peptide nanotube grafted hydrogels. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Intermolecular interaction in aqueous solution of binary blends of poly(acrylamide) and poly(ethylene glycol)
Authors: Lü Ting , Shan Guorong , Shang Songmin
Published: June 2010

The interaction between poly(acrylamide) (PAM) and poly(ethylene glycol) (PEG) in their solid mixture was studied by Fourier transform infrared spectroscopy (FTIR); and their interaction in aqueous solution was investigated by nuclear magnetic resonance spectroscopy (NMR). For the solid PAM/PEG mixtures, an induced shift of the >CO and >NH in amide group was found by FTIR. These results could demonstrate the formation of intermolecular hydrogen bonding between the amide group of PAM and the ether group of PEG. In the aqueous PAM/PEG solution system, the PAM and PEG associating with each other in water, i.e., the amide group of PAM interacting with the ether group of PEG through hydrogen bonding was also found by 1H NMR. Furthermore, the effects of different molecular weight of PAM on the strength of hydrogen bonding between PAM and PEG in water were investigated systemically. It was found that the hydrogen bonding interaction between PAM and PEG in water did not increase with the enlargement of the PAM molecular weight as expected. This finding together with the viscosity reduction of aqueous PAM/PEG solution with the PAM molecular weight increasing strongly indicated that PAM molecular chain, especially having high molecular weights preferred to form spherical clews in aqueous PEG solution. Therefore, fewer amide groups in PAM could interact with the ether groups in PEG. Based on these results, a mechanism sketch of the interaction between PAM and PEG in relatively concentrated aqueous solution was proposed. The fact that the phase separation of aqueous PAM/PEG solution occurs while raising the temperature indicates that this kind of hydrogen bonding between PAM and PEG in water is weak and could be broken by controlling the temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of an organic soluble and conducting polyaniline‐grafted multiwalled carbon nanotube core–shell nanocomposites by emulsion polymerization
Authors: Xu Jun , Yao Pei , Liu Litao , Jiang Zhongyi , He Fei , Li Mei , Zou Jingyu
Published: June 2010

Organic soluble and conducting polyaniline (PANI)‐grafted multiwalled carbon nanotube (MWNT) nanocomposites were synthesized by in situ emulsion polymerization. Dodecyl benzene sulfonic acid (DBSA) acted as both a dopant and emulsifier, and phenylamine groups grafted on the surface of the MWNTs via amide bonding joined in the in situ polymerization. As self‐assembly templates, multiwalled carbon nanotubes containing phenylamine groups (p‐MWNTs) were encapsulated by PANI to form a homogeneous core (p‐MWNTs)–shell (DBSA‐doped PANI) nanostructure. The attachment of soluble DBSA‐doped PANI chains on the surface of the p‐MWNTs via covalent bonding rendered the p‐MWNTs compatible with the polymer matrix and led to the nanocomposite being highly soluble and stable in tetrahydrofuran. The PANI chains grew restrictively on the surface of the p‐MWNTs, and the crystalline orders of the PANI coatings were enhanced. Because of the incorporation of the p‐MWNTs, the thermal stability of the nanocomposites was improved, and the conductivity of the nanocomposites at room temperature was increased by at least one order of magnitude over neat DBSA‐doped PANI. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of star‐shaped poly(ε‐caprolactone)‐b‐poly(L‐lactide) copolymers: From star architectures to crystalline morphologies
Authors: Ren Jie , Zhang Zhonghai , Feng Yue , Li Jianbo , Yuan Weizhong
Published: June 2010

Hexa‐armed star‐shaped poly(ε‐caprolactone)‐block‐poly(L‐lactide) (6sPCL‐b‐PLLA) with dipentaerythritol core were synthesized by a two‐step ring‐opening polymerization. GPC and 1H NMR data demonstrate that the polymerization courses are under control. The molecular weight of 6sPCLs and 6sPCL‐b‐PLLAs increases with increasing molar ratio of monomer to initiator, and the molecular weight distribution is in the range of 1.03–1.10. The investigation of the melting and crystallization demonstrated that the values of crystallization temperature (Tc), melting temperature (Tm), and the degree of crystallinity (Xc) of PLLA blocks are increased with the chain length increase of PLLA in the 6sPCL‐b‐PLLA copolymers. On the contrary, the crystallization of PCL blocks dominates when the chain length of PLLA is too short. According to the results of polarized optical micrographs, both the spherulitic growth rate (G) and the spherulitic morphology are affected by the macromolecular architecture and the length of the block chains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of azobenzene units on imidization kinetic of novel poly(ester amic acid)s and polymers properties before and after cyclodehydration
Authors: Schab‐Balcerzak Ewa , Janeczek Henryk , Kucharski Piotr
Published: June 2010

In this article, the imidization reaction kinetic of novel poly(ester amic acid)s with azobenzene units as side groups was studied by dynamic experiments by means of differential scanning calorimetry. Polymers differ in the number of chromophore moieties in their repeating unit and position in which azobenzene group is attached to the polymer chain. The kinetic parameters of poly(ester amic acid)s conversion to poly(ester imide)s was compared with data calculated for parent polymer, that is, without azobenzene groups. For the first time to our knowledge, the imidization kinetic of polymers with side azobenzene groups was studied. Kinetic parameters, such as the activation energy and frequency factor were estimated with the by Ozawa model [(E(O) and A(O)), respectively] and Kissinger model [(E(K) and A(K), respectively]. The values of activation energy determined with both models were in the range 167.1–198.3 kJ/mol. The lowest activation energy of imidization reaction exhibited polymer in which azobenzene units were placed between amide linkages. Polymers were characterized by FTIR, 1H‐NMR, X‐ray, and UV–vis methods. The glass transition temperature of resultant poly(ester imide)s was in the range of 217–237°C. The presence of chromophore units slightly decreased Tg and significantly improved their solubility and optical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Experimental investigation of the governing parameters in the electrospinning of poly(3‐hydroxybutyrate) scaffolds: Structural characteristics of the pores
Authors: Tehrani Ashkan Heidarkhan , Zadhoush Ali , Karbasi Saeed , Khorasani Saied Nouri
Published: June 2010

We sought to determine the impact of electrospinning parameters on a trustworthy criterion that could evidently improve the maximum applicability of fibrous scaffolds for tissue regeneration. We used an image analysis technique to elucidate the web permeability index (WPI) by modeling the formation of electrospun scaffolds. Poly(3‐hydroxybutyrate) (P3HB) scaffolds were fabricated according to predetermined conditions of levels in a Taguchi orthogonal design. The material parameters were the polymer concentration, conductivity, and volatility of the solution. The processing parameters were the applied voltage and nozzle‐to‐collector distance. With a law to monitor the WPI values when the polymer concentration or the applied voltage was increased, the pore interconnectivity was decreased. The quality of the jet instability altered the pore numbers, areas, and other structural characteristics, all of which determined the scaffold porosity and aperture interconnectivity. An initial drastic increase was observed in the WPI values because of the chain entanglement phenomenon above a 6 wt % P3HB content. Although the solution mixture significantly (p < 0.05) changed the scaffold architectural characteristics as a function of the solution viscosity and surface tension, it had a minor impact on the WPI values. The solution mixture gained the third place of significance, and the distance was approved as the least important factor. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Oxidized multiwalled carbon nanotubes as effective reinforcement and thermal stability agents of poly(lactic acid) ligaments
Authors: Chrissafis K. , Paraskevopoulos K. M. , Jannakoudakis A. , Beslikas T. , Bikiaris D.
Published: June 2010

In this study, nanocomposites of poly(lactic acid) (PLA) containing 0.5, 1, and 2.5 wt % oxidized multiwalled carbon nanotubes (MWCNT–COOHs) were prepared by the solved evaporation method. From transmission electron microscopy and scanning electron microscopy micrographs, we observed that the MWCNT–COOHs were well dispersed in the PLA matrix and, additionally, there was increased adhesion between PLA and the nanotubes. As a result, all of the studied nanocomposites exhibited higher mechanical properties than neat PLA; this indicated that the MWCNT–COOHs acted as efficient reinforcing agents, whereas in the nonoxidized multiwalled carbon nanotubes, the mechanical properties were reduced. Nanotubes can act as nucleating agents and, thereby, affect the thermal properties of PLA and, especially, the crystallization rate, which is faster than that of neat PLA. From the thermogravimetric data, we observed that the PLA/MWCNT–COOH nanocomposites presented relatively better thermostability than PLA; this was also verified from the calculation of activation energy. On the contrary, the addition of MWCNT–COOH had a negative effect on the enzymatic hydrolysis rate of PLA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010