Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Modified mesoporous silicates for the adsorption and decomposition of toxic gases

New adsorbents based on MCM-41 have been developed for the adsorption and decomposition of HCN and CNCl. Adsorption of CNCl is provided by diaminoalkylsilane tethers bound to the surface. Reactivity towards HCN is provided by Cu2+ ions complexed by the diamines. Overall reactivity towards the two gases depends on the balance between free amine and Cu2+ concentrations. The performance of these adsorbents is superior to that of carbon-based adsorbents in which alkylamine and copper(II) salt are physisorbed on the carbon surface

Preparation and characterisation of carbon-coated ceramic foams for organic vapour adsorption

Ceramic foam substrates of various porosities were coated with novolak resin, which was then subsequently carbonised and activated to develop a pore structure. The carbon forming the layer was characterised by thermal analysis, TPD and N2, CO2 and hexane vapour adsorption. It was found to be microporous with a high surface area (up to 1400 m2 g−1), which made it a good adsorbent for hexane vapour at ambient temperature. The carbon–ceramic interface was examined using SEM. The coated foams displayed a reduced pressure drop compared to carbon granules and had good dynamic hexane vapour adsorption characteristics. Depending on the foam architecture, hexane breakthrough was delayed for up to 78 min

The adsorption and decomposition of cyanogen chloride by modified inorganic molecular sieves

Aluminosilicate and silicate porous solids have been evaluated as supports for triethylenediamine (TEDA) for the adsorption and decomposition of cyanogen chloride. A series of silica-gel supports has been used to study the effect of varying pore size. A series of faujasitic zeolites has been used to examine the effect of the cation exchange capacity of the support and the type of exchangeable cation. Results show that the activity of adsorbed TEDA towards cyanogen chloride appears to increase with increasing support pore diameter, and TEDA seems to be activated by basic adsorption sites on the support. Cesium-exchanged zeolite supports are particularly active. In general, zeolite supports appear to confer significantly higher activity to TEDA than traditional activated carbon supports. A series of mesoporous MCM-41 and AlMCM-41 supports has also been studied, but the activities of adsorbed TEDA are lower than expected. Significantly, the specific surface area of the inorganic supports does not seem to be a primary factor in controlling adsorbed TEDA activity

An investigation of the porosity of carbons prepared by constant rate activation in air

Nutshell carbon was activated in air/N2 mixtures using controlled rate (CR) methods and the porosity characteristics compared with carbons activated conventionally in CO2 at 800 °C to the same degree of burn off. The advantages of CR activation in air include the use of lower temperatures and the avoidance of thermal runaway. It was also possible to prepare activated carbons with significant microporosity, showing that excessive external burn off was prevented. In the CR experiments, the rate of evolution of CO2 was controlled and constrained at a set level, either by altering the furnace temperature or the concentration of air in the activating gas. Although the highest micropore volumes (0.4 cm3 g−1) were obtained at 40% burn off with the conventional method, at 20% burn off, the CR method using air concentration to control CO2 evolution yielded carbons with similar micropore volumes (0.2 cm3 g−1) to those activated conventionall

A study of evolved gas control and its effect on carbon yield during the activation of carbon fibres by controlled rate methods

The rate of evolution of CO2 or CO was used to control the low temperature activation of carbon fibres in O2 mixtures via a feedback loop operated by a PC and in-house software. The CO2 or CO concentration was monitored by a mass spectrometer and its level kept constant by varying the O2 concentration using mass flow controllers. Experiments were carried out at the same evolution rates for identical times at temperatures of 500–800 °C. It was found that the rate of carbon burn off was not constant and varied with the temperature, especially where the rate of CO2 evolution was controlled. The proposed reason for this was the high temperature gas phase oxidation of CO. However, surface areas of up to 1500 m2 g−1 were produced by these methods and thermal runaway was avoide