Polymer coatings on magnesium-based implants for orthopedic applications

Nowadays, the need for bio-implants, which can gradually degrade after fulfilling the therapeutic tasks is continuously increasing. Under such situation, magnesium (Mg) and its alloys have been proposed and intensively studied as the new-generation medical implants due to their favorable biodegradability and biocompatibility. However, their swift corrosion in physiological environments can always cause an early fracture and further the surgical failure, greatly hindering their broad applications. Therefore, great efforts have been made to alter the degradation behaviors of Mg-based implants. Biodegradable polymeric surface coatings have been revealed to be a straightforward and effective strategy for retarding the fast degradation and improving the bioactivity of Mg and its alloys. This article reviews the recent progress of polymer-based coatings on Mg substrates, regarding the coating strategies, coating properties, and their performance in corrosive protection and biocompatibility promotion via in vitro as well as some in vivo models. The specific pros and cons of different polymeric coatings are also discussed. Finally, we put forward some perspectives on the future direction of polymeric coatings on biomedical Mg-based implants to better adapt to clinical trials.     

An overview of considerations and approaches for developing in vivo EPR for clinical applications

This paper describes the rationale for carrying out EPR studies in human subjects in the clinical setting and the potential approaches and specific steps needed to make such studies feasible and useful. The suggested operational approach is to have the initial applications occur in as clinically useful and simple a manner as possible, with the expectation that once the technique is introduced and accepted in the clinical setting, that more complex and/or more technically difficult applications will be able to be developed. The initial approach should be based on EPR spectroscopy at 1.2 GHz focusing on clinical applications for which in vivo EPR provides a clearly useful approach to important clinical problems for which currently there is no good alternative approach, that can be carried out by measurements within 10 mm of the surface. The suggested initial clinical applications are: guiding tumor therapy for tumors and vascular disease by direct measurements of tissue pO₂, characterizing and monitoring implanted drug delivery systems, and monitoring critical care.     

Environmental and Forensic applications of field-portable GC-MS: An overview

GC-MS can provide analytical information that is most reliable for many types of organic analyses. As field-portable GC-MS analytical systems evolve, the application scenarios have diversified as well. With the development of rugged fieldable systems, these instruments were demonstrated to be usable in the harsh environment of the jungle and in chemical demilitarization or military reconnaissance situations. Continuous unattended operations of a GC-MS for 12- or 24-hour monitoring applications in the field have been shown to be possible. A real-time algorithm strategy is proposed, which can be developed to aid in the advancement of field-portable mass spectrometry applied to chemical warfare agent analysis in military vehicles and can be used to raise the standard for field data quality. Each of these capabilities is discussed with the intent on reviewing analysis situations that can be expanded because of developments in field GC-MS instrumentation.     

Synthetic applications of 2-phenylselenenylenones—III : An overview

2-Phenylselenenylenones are versatile species which can be selectively converted into a number of different ketones and enones in high overall yields.     

Development and analytical applications of multispectral imaging techniques: An overview

A multispectral imaging spectrometer is an instrument that can simultaneously record spectral and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. By synergistic use of an acousto-optic tunable filter and a progressive scan camera capable of snap shot recording it was possible to develop a novel imaging spectrometer with a spatial resolution of a few microns and which can record, grab and store up to 33 images per second (at a function of time) or 16 images per second (as a function of wavelength). This overview article summarizes the instrumentation development of various imaging spectrometers and their applications including its use as the detector for the determination of identity and sequences of peptides synthesized by the combinatorial solid phase method.     

An overview of coupled cluster theory and its applications in physics

Summary What has since become known as the normal coupled cluster method (NCCM) was invented about thirty years ago to calculate ground-state energies of closed-shell atomic nuclei. Coupled cluster (CC) techniques have since been developed to calculate excited states, energies of open-shell systems, density matrices and hence other properties, sum rules, and the sub-sum-rules that follow from imbedding linear response theory within the NCCM. Further extensions deal both with systems at nonzero temperature and with general dynamical behaviour. More recently, a new version of CC theory, the so-called extended coupled cluster method (ECCM) has been introduced. It has the potential to describe such global phenomena as phase transitions, spontaneous symmetry breaking, states of topological excitation, and nonequilibrium behaviour. CC techniques are now widely recognized as providing one of the most universally applicable, most powerful, and most accurate of all microscopicab initio methods in quantum many-body theory. The number of successful applications within physics is now impressively large. In most such cases the numerical results are either the best or among the best available. A typical case is the electron gas, where the CC results for the correlation energy agree over the entire metallic density range to within less than 1 millihartree (or <1%) with the essentially exact Green's function Monte Carlo results. The role of CC theory within modern quantum many-body theory is first surveyed, by a comparison with other techniques. Its full range of applications in physics is then reviewed. These include problems in nuclear physics, both for finite nuclei and infinite nuclear matter; the electron gas; various integrable and nonintegrable models; various relativistic quantum field theories; and quantum spin chain and lattice models. Particular applications of the ECCM include the quantum hydrodynamics of a zero-temperature, strongly-interacting condensed Bose fluid; a charged impurity in a polarizable medium (e.g., positron annihilation in metals); and various anharmonic oscillator and spin systems.     

An overview of synthetic modification of nitrile group in polymers and applications

The physicochemical properties of polymers are mainly dependent on the nature of polymer backbone and/or pendant groups linked to the main chain. Therefore, synthetic modification of these functional groups via post functionalization is an important approach for obtaining novel polymeric systems with improved properties and targeted applications. In this context, the synthetic modifications of nitrile group in polymers into various useful functionalities have received considerable attention and several interesting applications of the resulting polymers have been identified. The majority of the studies are based on Polyacrylonitrile (PAN), and some isolated examples of nitrile functionalization in copolymers such as Poly (Styrene-co-Acrylonitrile) (SAN), Poly (Acrylonitrile-co-Butadiene-co-Styrene (ABS) and Nitrile Rubber (NBR) are available. These synthetic modifications are mainly accomplished by the reactions such as Nucleophilic addition, cycloaddition, reduction, and hydrolysis using various reagents. These studies describing the post-polymerization modifications of nitrile group in polymers reported during the last three decades are covered in this review.     

An overview on novel synthetic approaches and medicinal applications of benzimidazole compounds

Benzimidazole, a benzene-fused heterocyclic compound, has acquired significant attention in the field of contemporary medicinal chemistry because of its wide array of pharmacological activities. Nitrogen containing heterocyclic compounds are part of several therapeutically important agents with several recent patents shedding light on their worth. For these reasons, this review is concerned with different methods for synthesis of benzimidazole derivatives and their biological importance.     

An overview of LC–MS interfacing systems with selected applications

Advantages and limitations are described for the different LC–MS interfacing systems (moving belt; direct liquid introduction; thermospray; atmospheric pressure ionization with heated pneumatic nebulizer, electrospray, or high flow ion spray; particle beam; and continuous flow fast atom bombardment). Some comments are also made about interfacing capillary zone electrophoresis (CZE). The peculiarities of the various interfaces are described, as are liquid chromatographic requirements prior to mass spectrometry using the different ionization techniques. Selected biological and environmental applications are given.     

An overview on covalent organic frameworks: synthetic reactions and miscellaneous applications

Covalent organic frameworks (COFs) are an emerging class of porous crystalline materials which are completely constructed from organic building blocks through robust covalent bonds. High surface areas, compositional and structural tunability, low density, and superior stability have rendered COF candidates in a variety of applications, such as adsorption and separation, catalysis, electronics, chemical sensing, optics, and so forth. To better understand the structures and properties of COFs as well as the design principles, it is of great significance to learn about the linkages formed during synthetic reactions that contribute to the high crystallinity and stability of COFs. In this review, we will first discuss various linkages that have been utilized for COF construction up to date, followed by an outline of their miscellaneous applications, providing a comprehensive and detailed overview in this file.     

Analytical applications of electrochemiluminescence: an overview

The chemical transformations of electrogenerated ion-radicals of a number of complex organic compounds may be accompanied by emission of photons. An electrochemiluminescence (ECL) quantum contains information both on the kinetics of the heterogeneous electrode processes and on the subsequent homogeneous chemical reactions in the solution. Application of ECL to solution analysis provides advantages in comparison to electrochemical methods. Using ECL for electrode surface analysis allows information to be obtained on the rate of an electrochemical process simultaneously at all points of the electrode under analysis in real time, and that is the main difference between this method and the point-by-point testing specific to electrochemical methods. The potential of ECL for analytical chemistry is examined concerning the homogeneous ECL-analysis of solutions and the heterogeneous ECL-analysis of electrode surfaces. Received: 6 April 2000 / Revised: 23 June 2000 / Accepted: 27 June 2000     

Miniaturized tools and devices for bioanalytical applications: an overview

This article presents an overview of various miniaturized devices and technologies developed by our group. Innovative, fast and cheap procedures for the fabrication of laboratory microsystems based on commercially available materials are reported and compared with well-established microfabrication techniques. The modules fabricated and tested in our laboratory can be used independently or they can be set up in different configurations to form functional measurement systems. We also report further applications of the presented modules e.g. disposable poly(dimethylsiloxane) (PDMS) microcuvettes, fibre optic detectors, potentiometric sensors platforms, microreactors and capillary electrophoresis (CE) microchips as well as integrated microsystems e.g. double detection microanalytical systems, devices for studying enzymatic reactions and a microsystem for cell culture and lysis.     

Graphene electrochemistry: an overview of potential applications

Graphene, a 2D nanomaterial that possesses spectacular physical, chemical and thermal properties, has caused immense excitement amongst scientists since its freestanding form was isolated in 2004. With research into graphene rife, it promises enhancements and vast applicability within many industrial aspects. Furthermore, graphene possesses a vast array of unique and highly desirable electrochemical properties, and it is this application that offers the most enthralling and spectacular journey. We present a review of the current literature concerning the electrochemical applications and advancements of graphene, starting with its use as a sensor substrate through to applications in energy production and storage, depicting the truly remarkable journey of a material that has just come of age.     

Dendritic macromers for hydrogel formation: Tailored materials for ophthalmic,orthopedic, and biotech applications

Dendritic macromolecules are well‐defined highly branched macromolecules synthesized via a divergent or convergent approach. A salient feature of the macromolecules described herein, and a goal of our research effort, is to prepare dendritic macromolecules suitable for in vitro and in vivo use by focusing on biocompatible building blocks and biodegradable linkages. These dendritic macromolecules can be subsequently crosslinked to form hydrogels using a photochemical acrylate‐based or a chemical ligation strategy. The properties—mechanical, swelling, degradation, and so forth—of the hydrogels can be tuned by altering the composition, crosslinking chemistry, wt %, generation number and so forth. The utility and diverse applicability is demonstrated through successful use of these hydrogels in three unique applications: hydrogel adhesives for repairing corneal wounds, hydrogel scaffolds for cartilage tissue engineering, and hydrogel reaction chambers for high throughput screening of molecular recognition events. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 383–400, 2008.     

An overview of the applications of capillary electrophoresis to the analysis of pharmaceutical raw materials and excipients

Summary The use of capillary electrophoresis for the separation and quantitation of a range of pharmaceutical raw materials and excipients is reviewed. Capillary electrophoresis is shown to be a useful and versatile technique for a large number of applications. Features of the various methods include simplicity, detection of poor chromatophore species by extensive use of indirect UV detection or direct absorbance at low wavelengths, minimal operating costs and generation of high quality retrievable raw data. Specific novel examples described include separations of lactose, flavouring agents, inorganic salts, lecithin constituents, a range of organic acids, benzylalkonium chloride components, sodium lauryl sulphate, and the quality of input water. It is concluded that the versatility of CE will ensure that it is increasingly used in the analysis of pharmaceutical raw materials and excipients.     

Dialdehyde cellulose as a niche material for versatile applications: an overview

Cellulose - Dialdehyde cellulose (DAC) has garnered substantial scientific interest, thanks to broad spectrum of possible chemical reactions offered by the aldehyde moieties in its backbone. In the...     

Talc production: An overview

Luzenac Group, which presently produces and markets more than 1 million tons talc per year, has ensured its international development through the permanent search for a better adequacy between the very specific talc properties of its various deposits and their application in very different industrial fields.     

Metallasupramolecular architectures, an overview of functional properties and applications

The synthesis of metallasupramolecular architectures, such as two-dimensional squares, triangles and polygons, and three-dimensional cages and polyhedra, has attracted much interest in the past decade. These structures are designed to have novel specific shapes and dimensions with interesting functional properties. In this overview the functional properties of metallasupramolecular architectures are highlighted with emphasis on potential applications such as catalysis, cavity-directed synthesis and sensing, that can be performed with these materials.     

An overview of the bipartition model for charged particle transport

This paper systematically summarizes the progress to date and developments of the bipartition model, including its basic ideas and concepts, main mathematical formulae and numerical methods, and its relevant applications. The model has been extended from a transport theory for electrons in the medium energy range to a unified and accurate transport theory of charged particles, covering ion transport, atomic cascade collisions, particle emission from a surface including sputtering and the penetration of electrons in the radiation therapy energy range. The thirty figures in total give an extensive comparison between the results given by using the bipartition model and the data taken from other theories and experimental measurements, which shows that the bipartition model is an accurate, powerful and unified transport theory of charged particles. Some research being done using the bipartition model is mentioned briefly at the end of this paper.     

An overview of non-traditional nuclear threats

Summary In view of the terrorist threats to the United States, the country needs to consider new vectors and weapons related to nuclear and radiological threats against our homeland. The traditional threat vectors, missiles and bombers, have expanded to include threats arriving through the flow of commerce. The new commerce-related vectors include: sea cargo, truck cargo, rail cargo, air cargo, and passenger transport. The types of weapons have also expanded beyond nuclear warheads to include radiation dispersal devices (RDD) or &ldquo;dirty&apos; bombs. The consequences of these nuclear and radiological threats are both economic and life threatening. The defense against undesirable materials entering our borders involves extensive radiation monitoring at ports of entry. The radiation and other signatures of potential nuclear and radiological threats are examined along with potential sensors to discover undesirable items in the flow of commerce. Techniques to improve radiation detection are considered. A strategy of primary and secondary screening is proposed to rapidly clear most cargo and carefully examine suspect cargo.