Novel models to predict elevated intracranial pressure during intensive care and long-term neurological outcome after TBI

status: publishe

Data mining techniques for predicting acute kidney injury after elective cardiac surgery

status: publishe

Production of chlorella vulgaris biomass on uv-treated wastewater as an alternative for environmental sustainability on high-mountain fisheries

The sustained expansion of agricultural industry in Colombian high-mountain has led to an increased size of residues, especially untreated wastewater. This untreated water is an urgent matter for public and environmental health, not only by its nutrient concentration (composed especially of food residuals and feces) but also the presence of pathogens (virus, bacteria, etc.) which are discharged to the environment. The overall objective of this work is to evaluate the effect of UV-treated wastewater from a high-mountain fishery as culture media for the production of Chlorella vulgaris as a sustainable method for nutrient and water recirculation on the fishery production system. The UV-canal efficiency was evaluated by the implementation of an experimental factorial design (time, distance of the UV-lamps towards the canal, number of UV-lamps and the sample concentration) using STATISTICA 7.0 software. Results shown that time (3 to 5 minutes) and the number of lamps (3-4) of 15 Watts eliminate completely coliforms from the samples. After UV-treatment the resulting water was test as culture media for C. vulgaris production by the adjustment of C/N ratio (Sodium Carbonate/potassium nitrate) by the implementation of an experimental 23 factorial design. Results shown that higher nitrate concentrations (>0,22 g/L) and moderate carbonate concentrations (1 g/L) increase the final biomass concentration up to 4g/L in 20 days

Removal of cationic pollutants from water by xanthated corn cob: optimization, kinetics, thermodynamics, and prediction of purification process

The removal of Cr(III) ions and methylene blue (MB) from aqueous solutions by xanthated corn cob (xCC) in batch conditions was investigated. The sorption capacity of xCC strongly depended of the pH, and increase when the pH rises. The kinetics was well fitted by pseudo-second order and Chrastil’s model. Sorption of Cr(III) ions and MB on xCC was rapid during the first 20 min of contact time and, thereafter, the biosorption rate decrease gradually until reaching equilibrium. The maximum sorption capacity of 17.13 and 83.89 mg g-1 for Cr(III) ions and MB, respectively was obtained at 40 °C, pH 5 and sorbent dose 4 g dm-3 for removal of Cr(III) ions and 1 g dm-3 for removal of MB. The prediction of purification process was successfully carried out and the verification of theoretically calculated amounts of sorbent was confirmed by using packed-bed column laboratory system with recirculation of the aqueous phase. The wastewater from chrome plating industry was successfully purified, i.e. after 40 min concentration of Cr(III) ions was decreased lower than 0.1 mg dm-3. Also, removal of MB from the river water was successfully carried out and after 40 min removal efficiency was about 94 %

Structural basis of non-canonical transcriptional regulation by the A-bound iron-sulfur protein WhiB1 in M. tuberculosis

WhiB1 is amonomeric iron–sulfur cluster-containing transcription factor in the WhiB-like family that is widely distributed in actinobacteria including the notoriously persistent pathogen Mycobacterium tuberculosis (M. tuberculosis). WhiB1 plays multiple roles in regulating cell growth and responding to nitric oxide stress inM. tuberculosis, but its underlying mechanism is unclear. Here we report a 1.85 A° -resolution crystal structure of the [4Fe–4S] cluster-bound (holo- )WhiB1 in complex with the C-terminal domain of the 70-family primary sigma factor A of M. tuberculosis containing the conserved region 4 (A 4). Region 4 of the 70-family primary sigma factors is commonly used by transcription factors for gene activation, and holo-WhiB1 has been proposed to activate gene expression via binding to A 4. The complex structure, however, unexpectedly reveals that the interaction between WhiB1 and A 4 is dominated by hydrophobic residues in the [4Fe–4S] cluster binding pocket, distinct from previously characterized canonical 70 4-bound transcription activators. Furthermore, we show that holo-WhiB1 represses transcription by interaction with A 4 in vitro and that WhiB1 must interact with A 4 to perform its essential role in supporting cell growth in vivo. Together, these results demonstrate that holo-WhiB1 regulates gene expression by a non-canonical mechanism relative to well-characterized A 4-dependent transcription activators

Assessment of the Geothermal Development of Mexico

Mexico, with a 60 million population has an extension of almost 2 million square kilometers. A large number of volcanoes and hydrothermal manifestations are found in the area, particularly along the Pacific Coast. The electricity needs of this country require its installed capacity to be doubled every eight-and-a-half years. Although its main energy source is the hydrocarbons, new sources of energy are being investigated and developed. In 1973, at Cerro Prieto, a 75 MW plant was inaugurated utilizing geothermal steam, initiating in this way commercial exploitation of this energy. From there on an uninterrupted program of exploration and development has been followed, along and across the country. Probably the region with the highest potential of geothermal energy is the New-volcanic Belt, a zone 300 kilometers wide which crosses the country from the Pacific Coast to the Gulf of Mexico Coast. In this zone, the geothermal fields of Los Azufres, Los Negritos, Ixtlan de los Hervores, La Primavera and San Marcos are located. Sixteen wells have been drilled at Los Azufres, 14 good producers with an average temperature of 275 C. An area of 385 square kilometers is estimated can be exploited for steam production. By 1981, it is expected to have four wellhead turbogenerators rated 6 MW each. Two geothermal wells are now being drilled at La Primavera, with very good results. Temperatures of 275 C have been found at a depth of 800 m in the first well of the Rio Caliente module. The first two wells are now being drilled at Los Humeros geothermal zone. To date, 80 wells have been drilled at Cerro Prieto. In the last group of wells the producing stratum was found at a depth between 2000 and 3000 m. The temperature of this stratum is about 340 C, and each well has an average output of 200 tons per hour. Research is now being conducted to solve the problems encountered of casing corrosion, and for the development of better cementing materials and improved cementing techniques, since the results obtained have not been entirely satisfactory, being the life of the geothermal wells shortened, increasing the cost of power generation. Since its inauguration in 1973, Cerro Prieto has been generating electricity continuously, with increasing annual plant factors, better than 90 percent in the last three years. As of this date, the installed capacity at Cerro Prieto is 150 MW. The installation of a fifth unit of 30 MW is now underway. This unit will utilize low pressure steam flashed from the separated water, now being discarded from units 1 to 4. A flashing plant is currently being installed for this purpose. This means a 20 percent increase without drilling more wells. Future plans are the construction of two more plants of 200 MW each, for a total of 620 MW for May 1983. These units will be operating at slightly higher pressures than the existing ones. It is estimated that a total capacity of 40,000 MW could be installed by the year 2000, using steam obtained from the known geothermal areas of Mexico