Adenosine triphosphate citrate lyase mediates hypocitraturia in rats

Chronic metabolic acidosis increases proximal tubular citrate uptake and metabolism. The present study addressed the effect of chronic metabolic acidosis on a cytosolic enzyme of citrate metabolism, ATP citrate lyase. Chronic metabolic acidosis caused hypocitraturia in rats and increased renal cortical ATP citrate lyase activity by 67% after 7 d. Renal cortical ATP citrate lyase protein abundance increased by 29% after 3 d and by 141% after 7 d of acid diet. No significant change in mRNA abundance could be detected. Hypokalemia, which causes only intracellular acidosis, caused hypocitraturia and increased renal cortical ATP citrate lyase activity by 28%. Conversely, the hypercitraturia of chronic alkali feeding was associated with no change in ATP citrate lyase activity. Inhibition of ATP citrate lyase with the competitive inhibitor, 4S-hydroxycitrate, significantly abated hypocitraturia and increased urinary citrate excretion fourfold in chronic metabolic acidosis and threefold in K+-depletion. In summary, the hypocitraturia of chronic metabolic acidosis is associated with an increase in ATP citrate lyase activity and protein abundance, and is partly reversed by inhibition of this enzyme. These results suggest an important role for ATP citrate lyase in proximal tubular citrate metabolism.     

Temporal reasoning in blood gas diagnosis

Abstract: The aim of this paper is to describe a system whereby an intensive care unit patient's condition can be monitored and assessed over time using mostly blood gas analysis data. The first six sections analyse some major temporal reasoning approaches (with limited examples from other related areas) with the aim of selecting one for the task at hand. The last sections describe the PONJIP temporal blood gas analysis expert system with its main components, including user interfaces customised to the doctor's requirements. Since the overall aim of this paper is to describe an expert system used for the evaluation of the possible contribution of temporal medical reasoning from blood gas data, research specific to other application areas or data will not be covered here.     

The effect of resin finish on the dimensional stability of cotton knitted fabric

In this article, the effect of resin finish on the degree of set is discussed. Furthermore, the relationship of the degree of set and dimensional stability is analyzed. After relaxation treatments, the yarns in a fabric would be set at a certain level. As the fabric is subjected to prolonged relaxation treatments, the yarn will become more set until the shape of the unraveled yarn is similar to the shape of the loop in the fabric. The yarn that is removed from a knitted fabric has a curvature value close to zero, and the curvature is exactly as the corresponding position at the knitted loop. From previous research, it is known that the degree of set affects the dimensional properties in a plain knitted fabric. In this article, the degree of set increases with resin level. It explains why the resin finish can stabilize the dimensional properties indirectly.     

Influence of different extraction temperatures and methanol solvent percentages on the total phenols and total flavonoids from the heartwood and bark of Acacia auriculiformis

Acacia auriculiformis heartwood and bark were obtained, dried under shelter for 2 weeks and pulverized into powdered form to be extracted with the following extraction temperatures of 35, 55 and 75 °C and methanol solvent percentages of 55, 65 and 75 % for 3 h in a water bath. The material ratio used was 1:20 (pulverized samples: solvent). The total phenolics and flavonoids yield was determined by using a Thermo Scientific Genesys 10 UV–Visible Spectrophotometer. The optimum total phenolics and flavonoids yield were achieved by extraction with an extraction temperature of 75 °C and a methanol solvent percentage of 75 % for both the heartwood [75.44 % (total phenolics) and 36.64 % (total flavonoids)] and bark [87.18 % (total phenolics) and 99.10 % (total flavonoids)] of A. auriculiformis trees.     

Time Diversity with Adaptive Error Detection to Combat Rayleigh Fading in Digital Mobile Radio

A new diversity technique is proposed to combat Rayleigh fading in digital mobile radio systems transmitting speech signals. The speech signals are μ-law PCM encoded (mu = 255, 8 kHz sampling, 8 bits/code word, 64 kbit/s data rate), and alternate data words are used to form two streams called "odd" and "even." The even stream is delayed by τ seconds and the streams are interleaved prior to radio transmission using two-level PSK modulation. At the receiver the odd data stream is delayed by τ and interleaved with the even stream. Consequently, if an error burst occurs, the effect of the reshuffling of the data stream is, in general, to place words with bit errors in juxtaposition to those correctly received. After μ-law PCM decoding of the words, a statistical error detection strategy is evoked to identify the erroneous samples. These samples are replaced by adjacent sample interpolation to give the recovered speech sequence. No recourse to channel protection coding is made. In our experiments a Rayleigh fading envelope was generated from a hardware simulator and stored in a computer, along with four sentences of speech. The system was then simulated and the recovered speech perceived. The objective performance measures were segmental SNR for the audio signal, and BER. Different error detection strategies were examined and restrictions on τ investigated. For a mobile speed of 30 mph, SNR values of 32, 21, and 16 dB were obtained for BER values of 0.1, 1, and 2 percent, corresponding to SNR gains over an uncorrected system of 3, 9, and 11 dB, respectively.     

Hydrogen adsorption on and diffusion through MoS2 monolayer: First-principles study

We investigate the hydrogen adsorption on and diffusion through the MoS₂ monolayer based on density-functional theory. We show that the hydrogen atom prefers to bond to the S atom at the monolayer, leading to enhanced conductivity. The hydrogen atom can also adsorb at the middle of the hexagon ring by overcoming an energy barrier of 0.57 eV at a strain of 8%. Also, we show that the MoS₂ monolayer is flexible and any mechanical deformation of the monolayer is reversible because the extension of the Mo–S bond is much smaller than the applied strain. The monolayer can block the diffusion of hydrogen molecule from one side to the other due to a high energy barrier (6.56 eV). However, the barrier can be reduced to 1.38 eV at a strain of 30% and even totally removed by creating S vacancies and applying a strain of 15%. The MoS₂ monolayer may find applications in sensors to detect hydrogen, and as mechanical valve to control the concentration of hydrogen gas.