Experimental and Theoretical Investigations of a Ferrous / Ascorbate Complex

<p>The importance of trace metal ions in biological processes has been known for some time, but the role of chelating molecules in the human body is a comparatively new and interesting field of research Schubert, j., 1966, Scientific American, 214, no. 5, 40. Among the important complexes occuring in the body are haemoglobin, containing iron, and vitamin B-12, containing cobalt, both essential to human health. Other well-known naturally occuring complexes include cytochrome oxidase, containing both iron and copper, and chlorophyll, containing magnesium. The transition metal ions of the First Transition Series are well-known for their ability to form complexes with suitable ligands, and in particular with chelate ligands which can seize the metal ion like a claw (chele means claw in Greek). Many of these complexes have been characterized experimentally, and their properties interpreted by theoretical calculations. However, the complexes arising from biological systems are much more difficult to study, partly because of their greater size and special properties.</p>

Experimental and Theoretical Investigations of a Ferrous / Ascorbate Complex

<p>The importance of trace metal ions in biological processes has been known for some time, but the role of chelating molecules in the human body is a comparatively new and interesting field of research Schubert, j., 1966, Scientific American, 214, no. 5, 40. Among the important complexes occuring in the body are haemoglobin, containing iron, and vitamin B-12, containing cobalt, both essential to human health. Other well-known naturally occuring complexes include cytochrome oxidase, containing both iron and copper, and chlorophyll, containing magnesium. The transition metal ions of the First Transition Series are well-known for their ability to form complexes with suitable ligands, and in particular with chelate ligands which can seize the metal ion like a claw (chele means claw in Greek). Many of these complexes have been characterized experimentally, and their properties interpreted by theoretical calculations. However, the complexes arising from biological systems are much more difficult to study, partly because of their greater size and special properties.</p>

The transfer and persistence of metals in latent fingermarks

In forensic science, knowledge and understanding of material transfer and persistence is inherent to the interpretation of trace evidence and can provide vital information on the activity level surrounding a crime. Detecting metal ions in fingermark residue has long been of interest in the field of forensic science, due to the possibility of linking trace metal ion profiles to prior activity with specific metal objects (e.g. gun or explosive handling). Unfortunately, the imaging capability to visualise trace metal ions at sufficient spatial resolution to determine their distribution within a fingermark (micron level) was not previously available. Here, we demonstrate for the first time transfer and persistence of metals in fingermarks, at micron spatial resolution, using synchrotron sourced x-ray fluorescence microscopy. Fingermarks were taken before and after brief handling of a gun barrel, ammunition cartridge case and party sparkler to demonstrate the transfer of metals. The results reveal increased metal content after contact with these objects, and critically, a differential pattern of metal ion increase was observed after handling different objects. Persistence studies indicate that these metals are removed as easily as they are transferred, with a brief period of hand washing appearing to successfully remove metallic residue from subsequent fingermarks. Preliminary work using x-ray absorption near edge structure spectroscopic mapping highlighted the potential use of this technique to differentiate between different chemical forms of metals and metal ions in latent fingermarks. It is anticipated that these findings can now be used to assist future work for the advancement of trace metal detection tests and fingermark development procedures

Production of spiculisporic acid by Talaromyces trachyspermus in fed-batch bioreactor culture

Spiculisporic acid (SA) is a fatty acid-type biosurfactant with one lactone ring and two carboxyl groups. It has been used in metal removers and cosmetics, because of its low propensity to cause irritation to the skin, its anti-bacterial properties, and high surface activity. In the present study, we report an effective method for producing SA by selecting a high-producing strain and investigating the effective medium components, conditions, and environments for its culture. Among the 11 kinds of Talaromyces species, T. trachyspermus NBRC 32238 showed the highest production of a crystalline substance, which was determined to be SA using NMR. The strain was able to produce SA under acidic conditions from hexoses, pentoses, and disaccharides, with glucose and sucrose serving as the most appropriate substrates. Investigation of nitrogen sources and trace metal ions revealed meat extract and FeCl3 as components that promoted SA production. Upon comparing the two types of cultures with glucose in a baffle flask or aeration bioreactor, SA production was found to be slightly higher in the flask than in the reactor. In the bioreactor culture, sucrose was found to be an appropriate substrate for SA production, as compared to glucose, because with sucrose, the lag time until the start of SA production was shortened. Finally, fed-batch culture with sucrose resulted in 60 g/L of SA, with a total yield of 0.22 g SA/g sucrose and a productivity of 6.6 g/L/day.

Transformation of Glass Fiber Waste into Mesoporous Zeolite-Like Nanomaterials with Efficient Adsorption of Methylene Blue

Recycling and reusing glass fiber waste (GFW) has become an environmental concern, as the means of disposal are becoming limited as GFW production increases. Therefore, this study developed a novel, cost-effective method to turn GFW into a mesoporous zeolite-like nanomaterial (MZN) that could serve as an environmentally benign adsorbent and efficient remover of methylene blue (MB) from solutions. Using the Taguchi optimizing approach to hydrothermal alkaline activation, we produced analcime with interconnected nanopores of about 11.7 nm. This MZN had a surface area of 166 m2 g−1 and was negatively charged with functional groups that could adsorb MB ranging from pH 2 to 10 and all with excellent capacity at pH 6.0 of the maximum Langmuir adsorption capacity of 132 mg g−1. Moreover, the MZN adsorbed MB exothermically, and the reaction is reversible according to its thermodynamic parameters. In sum, this study indicated that MZN recycled from glass fiber waste is a novel, environmentally friendly means to adsorb cation methylene blue (MB), thus opening a gateway to the design and fabrication of ceramic-zeolite and tourmaline-ceramic balls and ceramic ring-filter media products. In addition, it has environmental applications such as removing cation dyes and trace metal ions from aqueous solutions and recycling water.

Production of spiculisporic acid by Talaromyces trachyspermus in fed-batch bioreactor culture

Spiculisporic acid (SA) is a fatty acid-type biosurfactant with one lactone ring and two carboxyl groups. It has been used in metal removers and cosmetics, because of its low propensity to cause irritation to the skin, its antibacterial properties, and high surface activity. In the present study, we report an effective method for producing SA by selecting a high-producing strain and investigating the effective medium components, conditions, and environments for its culture. Among the 11 kinds of Talaromyces species, T. trachyspermus NBRC 32238 showed the highest production of a crystalline substance, which was determined to be SA using NMR. The strain was able to produce SA under acidic conditions from hexoses, pentoses, and disaccharides, with glucose and sucrose serving as the most appropriate substrates. Investigation of nitrogen sources and trace metal ions revealed meat extract and FeCl3 as components that promoted SA production. Upon comparing the two types of cultures with glucose in a baffle flask or aeration bioreactor, SA production was found to be slightly higher in the flask than in the reactor. In the bioreactor culture, sucrose was found to be an appropriate substrate for SA production, as compared to glucose, because with sucrose, the lag time until the start of SA production was shortened. Finally, fed-batch culture with sucrose resulted in 60 g/L of SA, with a total yield of 0.22 g SA/g sucrose and a productivity of 6.6 g/L/d.

Review of the local tissue reaction to metallic spinal implant debris: Ions and nanoparticles

Biologic reactivity to implant debris is the primary determinant of long-term clinical performance. The metallic implants placed in human bodies can exhibit electrochemical or mechanical corrosion that yields in the liberation of metallic products. Such implants-derived metal wear products can be present in the form of metal ions and particulate metal debris with still unknown effects on human health. In situ generation of metallic wear particles, corrosion products and in vivo trace metal ions release from metal and metallic alloys implanted into the body in spine surgery is becoming a major cause for concern regarding the health and safety of patients. In vivo clinical studies addressing the adverse local tissue reaction effects of metallic wear products on surrounding soft tissues and bodily fluids are less numerous. Although numerous studies have focused on the clinical significance of corrosion and wear of hip and knee replacements, research involving spine instrumentation is not well documented. This review explores how migration of metallic wear nanoparticles and trace metal ions in the area of metallic spinal implants influences the surrounding tissues and bodily fluids, and what the clinical consequences of this process may be.