EXTRACTION OF OIL AND PETROLEUM PRODUCTS FROM WATER SOLUTIONS BY NATURAL ADSORBENTS

When solving the problem of wastewater treatment till the required parameters, adsorption methods have no analogs, which allow purifying sewage from oil products to any required level without introducing secondary pollution. Here has been studied the possibility of using natural and modified alumоsilicates for extraction of oil and petroleum products from sewage of oil refineries to the norms of discharge of fishery reservoirs. Alumosilicates of the Transbaikal deposit were used as the object of the study. In order to improve the adsorption characteristics of natural alumosilicates, they were subjected to microwave activation and modification by HCl. The adsorption value of petroleum products was 8.9 mg/g for natural adsorbents; 15.10 mg/g-for alumosilicates activated by microwave; 19.30 mg/g – for alumosilicates modified by HCl. Adsorption of petroleum products is described by Langmuir and BET models. The main adsorption parameters of these models are determined. The values of correlation coefficients indicate that the adsorption of petroleum products by natural adsorbents and alumosilicates, activated by microwave, best describes the model of adsorption of BET. For alumosilicates modified HCl best true equation Langmuir. It is established that the activation and modification of natural alumosilicates allows to improve the adsorption capacity and causes a reduction in time of the completeness of the saturation of the adsorbents, as evidenced by a decrease in the standardized Gibbs energy is the determining factor when increasing the rate of cleaning. In the paper, it is assumed that microwave radiation heats water in the sorbent, and this leads to an increase in its partial pressure in the pores, there is an excess pressure, which leads to an increase in the pore size, and, consequently, to an increase in the adsorption capacity. In the case of modification of HCl, the increase in the adsorption capacity is due to changes in the textural characteristics of the adsorbent, an increase in the specific surface area and the specific pore volume. Activation and modification of natural alumosilicates made it possible to increase the purification efficiency from 86.8 to 97.3 % and to reduce the residual concentration from 0.29 to 0.059 mg/dm3.

Hepatorenal Syndrome

Hepatorenal syndrome is a severe complication of end-stage cirrhosis characterized by increased splanchnic blood flow, hyperdynamic state, a state of decreased central volume, activation of vasoconstrictor systems, and extreme kidney vasoconstriction leading to decreased GFR. The contribution of systemic inflammation, a key feature of cirrhosis, in the development of hepatorenal syndrome has been highlighted in recent years. The mechanisms by which systemic inflammation precipitates kidney circulatory changes during hepatorenal syndrome need to be clarified. Early diagnosis is central in the management and recent changes in the definition of hepatorenal syndrome help identify patients at an earlier stage. Vasoconstrictive agents (terlipressin in particular) and albumin are the first-line treatment option. Several controlled studies proved that terlipressin is effective at reversing hepatorenal syndrome and may improve short-term survival. Not all patients are responders, and even in responders, early mortality rates are very high in the absence of liver transplantation. Liver transplantation is the only curative treatment of hepatorenal syndrome. In the long term, patients transplanted with hepatorenal syndrome tend to have lower GFR compared with patients without hepatorenal syndrome. Differentiating hepatorenal syndrome from acute tubular necrosis (ATN) is often a challenging yet important step because vasoconstrictors are not justified for the treatment of ATN. Hepatorenal syndrome and ATN may be considered as a continuum rather than distinct entities. Emerging biomarkers may help differentiate these two conditions and provide prognostic information on kidney recovery after liver transplantation, and potentially affect the decision for simultaneous liver–kidney transplantation.

Specific force of the vastus lateralis in adults with achondroplasia

Achondroplasia is a clinical condition defined by shorter stature and disproportionate limb length. Force production in able-bodied individuals (controls) is proportional to muscle size, but given the disproportionate nature of achondroplasia, normalizing to anatomical cross-sectional area (ACSA) is inappropriate. The aim of this study was to assess specific force of the vastus lateralis (VL) in 10 adults with achondroplasia (22 ± 3 yr) and 18 sex-matched controls (22 ± 2 yr). Isometric torque (iMVCτ) of the dominant knee extensors (KE) and in vivo measures of VL muscle architecture, volume, activation, and patella tendon moment arm were used to calculate VL physiological CSA (PCSA), fascicle force, and specific force in both groups. Achondroplasic muscle volume was 53% smaller than controls (284 ± 36 vs. 604 ± 102 cm3, P < 0.001). KE iMVCτ was 63% lower in achondroplasia compared with controls (95 ± 24 vs. 256 ± 47 N⋅m, P < 0.001). Activation and moment arm length were similar between groups ( P > 0.05), but coactivation of bicep femoris of achondroplasic subjects was 70% more than controls (43 ± 20 vs. 13 ± 5%, P < 0.001). Achondroplasic subjects had 58% less PCSA (43 ± 10 vs. 74.7 ± 14 cm2, P < 0.001), 29% lower fascicle force (702 ± 235 vs. 1704 ± 303 N, P < 0.001), and 29% lower specific force than control subjects (17 ± 6 vs. 24 ± 6 N⋅cm−2, P = 0.012). The smaller VL specific force in achondroplasia may be attributed to infiltration of fat and connective tissue, rather than to any difference in myofilament function. NEW & NOTEWORTHY The novel observation of this study was the measurement of normalized force production in a group of individuals with disproportionate limb length-to-torso ratios.

Effects of lung volume on diaphragm EMG signal strength during voluntary contractions

The use of esophageal recordings of the diaphragm electromyogram (EMG) signal strength to evaluate diaphragm activation during voluntary contractions in humans has recently been criticized because of a possible artifact created by changes in lung volume. Therefore, the first aim of this study was to evaluate whether there is an artifactual influence of lung volume on the strength of the diaphragm EMG during voluntary contractions. The second aim was to measure the required changes in activation for changes in lung volume at a given tension, i.e., the volume-activation relationship of the diaphragm. Healthy subjects ( n = 6) performed contractions of the diaphragm at different transdiaphragmatic pressure (Pdi) targets (range 20–160 cmH2O) while maintaining chest wall configuration constant at different lung volumes. The diaphragm EMG was recorded with a multiple-array esophageal electrode, with control of signal contamination and electrode positioning. The effects of lung volume on the EMG were studied by comparing the crural diaphragm EMG root mean square (RMS), an index of crural diaphragm activation, with an index of global diaphragm activation obtained by normalizing Pdi to the maximum Pdi at the given muscle length (Pdi/P[Formula: see text]) at the different lung volumes. We observed a direct relationship between RMS and Pdi/P[Formula: see text]independent of diaphragm length. The volume-activation relationship of the diaphragm was equally affected by changes in lung volume as the volume-Pdi relationship (60% change from functional residual capacity to total lung capacity). We conclude that the RMS of the diaphragm EMG is not artifactually influenced by lung volume and can be used as a reliable index of diaphragm activation. The volume-activation relationship can be used to infer changes in the length-tension relationship of the diaphragm at submaximal activation/contraction levels.

Modulation of K-Cl cotransport in volume-clamped low-K sheep erythrocytes by pH, magnesium, and ATP

Cellular pH, ionized Mg (Mgi2+), and MgATP concentration of red blood cells, concomitantly with cell volume, change transiently during circulation. The action of these three effectors on Cl-dependent K efflux was examined in low-K sheep red blood cells with constant cell volume. Activation of K-Cl efflux by Mgi2+ extraction required ATP, suggesting that phosphorylation of a putative component occurred before Mgi2+ extraction. Conversely, Mg and ATP were synergistic inhibitors of K-Cl cotransport, since maximal inhibition was observed only in cells containing both ATP and > 300 microM Mgi2+. Both findings suggest dual roles for Mg and ATP. At 300-600 microM Mgi2+, lowering the pH from approximately 7.4 to approximately 6.5 stimulated K-Cl efflux only in fed cells, suggesting that protons oppose or release the inhibition by Mgi2+ and ATP. A direct effect of both protons and Mgi2+ on the cotransporter is suggested by their inhibition of K-Cl efflux in ATP-depleted cells. These findings are discussed in light of the current phosphorylation/dephosphorylation hypothesis.