Determination of Urinary Neopterin/Creatinine Ratio to Distinguish Active Tuberculosis from Latent Mycobacterium tuberculosis Infection.

BACKGROUND: Biomarkers to distinguish latent from active Mycobacterium (M.) tuberculosis infection in clinical practice are lacking. The urinary neopterin/creatinine ratio can quantify the systemic interferon-gamma effect in patients with M. tuberculosis infection. METHODS: In a prospective observational study, urinary neopterin levels were measured by enzyme linked immunosorbent assay in patients with active tuberculosis, in people with latent M. tuberculosis infection, and in healthy controls and the urinary neopterin/creatinine ratio was calculated. RESULTS: We included a total of 44 patients with M. tuberculosis infection and nine controls. 12 patients had active tuberculosis (8 of them culture-confirmed). The median age was 15 years (range 4.5 to 49). Median urinary neopterin/creatinine ratio in patients with active tuberculosis was 374.1 micromol/mol (129.0 to 1072.3), in patients with latent M. tuberculosis infection it was 142.1 (28.0 to 384.1), and in controls it was 146.0 (40.3 to 200.0), with significantly higher levels in patients with active tuberculosis (p < 0.01). The receiver operating characteristics curve had an area under the curve of 0.84 (95% CI 0.70 to 0.97) (p < 0.01). CONCLUSIONS: Urinary neopterin/creatinine ratios are significantly higher in patients with active tuberculosis compared to patients with latent infection and may be a significant predictor of active tuberculosis in patients with M. tuberculosis infection

Performance up gradation of static VAR compensator with thyristor binary switched capacitor and reactor using model reference adaptive controller

There are various static var compensator configurations are available and listed in the literature. Their performances are evaluated based on their voltage support, dynamic response, losses, cost, and additional filter requirement, if any. In this paper, efforts are made to improve the dynamic performance parameter such as rise time, settling time, and peak overshoots. A new topology with an adaptive controller is presented, in which capacitor and reactor banks are divided in their binary values and connected in the shunt. Capacitor and reactor banks are operated by thyristorised switches. Both these banks are operated in closed-loop form as a cascade control. Amongst these, capacitor bank operates as coarse control, and reactor bank acts as fine control. For the performance enhancement, a model reference adaptive controller is used. The system identification toolbox is used to evaluate the mathematical model of the plant with Matlab. The model\u27s performance was analyzed deeply by the adaptive controller with different reference models such as critical, under, and overdamped. The performance parameters such as rise time, settling time, and peak overshoot in the form of reactive power swings, are evaluated and plotted for different adaptive gains using MIT rules

Asphericity of a length four relative presentation

We consider the relative group presentation P = where X = { x \} and R = { xg_1 xg_2 xg_3 x^{-1} g_4 }. We show modulo a small number of exceptional cases exactly when P is aspherical. If the subgroup H of G is given by H = then the exceptional cases occur when H is isomorphic to one of C_5,C_6,C_8 or C_2 X C_4

Determinants of drug absorption in different ECMO circuits

Purpose: The aim of this in vitro study was to evaluate potential determinants of drug loss in different ECMO circuits. Methods: Midazolam, morphine, fentanyl, paracetamol, cefazolin, meropenem and vancomycin were injected into three neonatal roller pump, two paediatric roller pump and two clinically used neonatal roller pump circuits, all with a silicone membrane, and two neonatal centrifugal pump circuits with polypropylene hollow-fibre membranes. Serial blood samples were taken from a post-oxygenator site. Drug recovery was calculated as the ratio between the determined and the theoretical maximum concentration. The latter was obtained by dividing dose by theoretical circuit volume. Results: Average drug recoveries at 180 min in three neonatal silicone membrane roller pump circuits were midazolam 0.62%, morphine 23.9%, fentanyl 0.35%, paracetamol 34.0%, cefazolin 84.3%, meropenem 82.9% and vancomycin 67.8%. There was a significant correlation between the lipophilicity of the drug expressed as log P and the extent of drug absorption, p < 0.001. The recovery of midazolam and fentanyl in centrifugal pump circuits with hollow-fibre membrane oxygenator was significantly higher compared to neonatal roller pump circuits with silicone membranes: midazolam 63.4 versus 0.62%, fentanyl 33.8 versus 0.35%, p < 0.001. Oxygenator size and used circuits do not significantly affect drug losses. Conclusions: Significant absorption of drugs occurs in the ECMO circuit, correlating with increased lipophilicity of the drug. Centrifugal pump circuits with hollow-fibre membrane oxygenators show less absorption for all drugs, most pronounced for lipophilic drugs. These results suggest that pharmacokinetics and hence optimal doses of these drugs may be altered during ECMO

Smart Operations of Air-Conditioning and Lighting Systems in a Government Buildings for Peak Power Reduction

This paper presents the achievements of implementing smart operations strategies for air-conditioning (A/C) and lighting systems in Justice Palace Complex (JPC), Kuwait during the summer 2007. The peak load of this building was 3700 kW. The achievements are summarized as direct savings between 13:00 and 22:00 h by closing supply and return air fans of 52 air-handling units with a connected load 400 kW, and an additional saving of 550 kW during the same period by optimizing the cooling production and distribution. Also an all time saving of 22 kW by de-lamping, and additional saving of 27 kW through TDC of lighting were achieved. In conclusion project achieved an overall reduction in power demand of around 20% between 13:00 to 17:00 h and reduction ranging from 7% to 15% between 17:00 to 20:00 h

Peak Power Reduction Strategies for the Lighting Systems in Government Buildings

Lighting systems are the second major contributor to the peak power demand and energy consumption in buildings after A/C systems. They account for nearly 20% of the peak power demand and 15% of the annual energy consumption. Thus energy efficient lighting systems and their smart operation can be very effective in reducing the national peak power and energy consumption, particularly for a country like Kuwait where power demand grew from 6750 MW in 2001 to 9075 MW in 2007 (MEW, 2002- 2008). This paper presents an approach developed to reduce the peak power demand in the lighting. The approach included optimum use of daylight, time of day control and delamping. The implementation of this approach for eight government buildings with occupancy of between 7:30 and 2:30 and peak power demand of 29.3 MW achieved a reduction of 2 MW in the peak power demand (around 7%). More importantly this 7% in peak load reduction and 10,628 MWh reduction in the annual energy consumption was achieved without any added cost. Also, the paper includes recommendations for retrofitting cost effective energy efficient lighting systems and implementation of more effective control

Management of Power Demand through Operations of Building Systems

In hot summers, the demand for electrical power is dominated by the requirements of the air-conditioning and lighting systems. Such systems account for more than 80% of the peak electrical demand in Kuwait. A study was conducted to explore the potential for managing the peak electrical demand through improved operation strategies for building systems. Two buildings with partial occupancy patterns and typical peak loads of 1 and 2.2 MW were investigated. Changes to the operation of building systems included utilizing the thermal mass to reduce cooling production and distribution during the last hour of occupancy, time-of-day control of chillers and auxiliaries, and de-lamping. The implemented operational changes led to significant reductions in building loads during the hours of national peak demand. The achieved savings reached 31% during the critical hour, and up to 47% afterwards. Daily energy savings of 13% represented an added benefit. Additional operational changes could lead to further savings in peak power when implemented

Implementation of Smart Operation Strategies for Air-Conditioning and Lighting Systems for Ministries Complex in the State of Kuwait

The smart operation strategies were implemented for Air-Conditioning (A/C) and lighting systems to reduce the national load at Ministries Complex (MC) in the state of Kuwait. The A/C system in MC is a district cooling system that comprises of 8 chillers with water-cooled condensers and four circuits of chilled water distribution with their independent pumps feeding to 184 air-handling units (AHUs), including 26 independent fresh air units. Total connected load of A/C systems is 8,867 kW, while fan motors of AHUs account for 2,390 kW. Lighting system in MC comprises mostly of energy efficient T12 fluorescent tubes and compact fluorescent lamps with a total connected load of 2,254 kW. Pre Closing Treatment (PCT) between 13:00 and 14:00 h, when the building was still occupied, was explored. Fresh-air AHUs were closed at 13:00 h instead of 14:30. Also, Time-of-Day Control (TDC) for AHUs and lighting systems along with the cooling production and cooling distribution systems was applied between 14:00 and 15:30 h, in line with the building occupancy for each building at MC. PCT and TDC schemes for chillers, AHUs and lighting systems were carried out through the Building Automation System (BAS). Implementation of the smart operation strategies for A/C and lighting systems was successful at MC. The temperature build up did not exceed 1°C during PCT scheme and the temperature did not exceed 28°C during TDC scheme. The savings in peak load demand were 610 kW between 13:00 and 14:00 h, 4,500 kW between 14:00 and 15:00 h, and 6,897 after 15:30 h. The reduction of 4,500 kW at 15:00 h is equivalent to $7.6 million towards constructing power plant and distribution network. Savings of 13,720 kWh in daily energy consumption was achieved due the implementation of the smart operation strategies. These savings led to a reduction of$1,500 per typical summer day of the MEW fuel bill and 8,918 kg/day of CO2 emissions. To make MC building more energy efficient, it is recommended to retrofit AHUs and secondary chilled water pumps with variable frequency drives (VFDs)