Reduction of nitrogen oxide emissions in lime kiln

Different nitrogen oxide removal technologies for rotary lime kiln are studied in this thesis, the main focus being in commercial technologies. Post-combustion methods are investigated in more detail as potential possible NOx removal with combustion methods in rotary lime kiln is more limited or primary methods are already in use. However, secondary methods as NOx scrubber, SNCR or SCR technologies are not listed as the Best Available Technologies defined by European Union. BAT technologies for NOx removal in lime kiln are (1) Optimised combustion and combustion control, (2) Good mixing of fuel and air, (3) Low-NOx burner and (4) Fuel selection/low-N fuel. SNCR method is the most suitable technique for NOx removal in lime kiln when NOx removal from 50 % to 70 % is required in case primary methods are already in use or cannot be applied. In higher removal cases ammonia slip is an issue in SNCR. By using SCR better NOx reduction can be achieved but issues with catalyst materials are expected to arise because of the dust and sulphur dioxide which leads to catalyst poison formation in lower flue gas temperatures. NOx scrubbing has potential when simultaneous NOx and SO2 removal is required. The challenge is that NO cannot be scrubbed directly, but once it is oxidized to NO2 or further scrubbing can be performed as the solubility of NO2 is higher. Commercial installations have not been made regarding SNCR, SCR or NOx scrubbing regarding rotary lime kiln. For SNCR and SCR the closest references come from cement industry.

Reduction of intraspecific aggression in adult rats by neonatal treatment with a selective serotonin reuptake inhibitor

Most studies suggest that serotonin exerts an inhibitory control on the aggression process. According to experimental evidence, this amine also influences growth and development of the nervous tissue including serotoninergic neurons. Thus, the possibility exists that increased serotonin availability in young animals facilitates a long-lasting effect on aggressive responses. The present study aimed to investigate the aggressive behavior of adult rats (90-120 days) treated from the 1st to the 19th postnatal day with citalopram (CIT), a selective serotonin reuptake inhibitor (20 mg/kg, sc, every 3 days). Aggressive behavior was induced by placing a pair of rats (matched by weight) in a box (20 x 20 x 20 cm), and submitting them to a 20-min session of electric footshocks (five 1.6-mA - 2-s current pulses, separated by a 4-min intershock interval). When compared to the control group (rats treated for the same period with equivalent volumes of saline solution), the CIT group presented a 41.4% reduction in the duration of aggressive response. The results indicate that the repeated administration of CIT early in life reduces the aggressive behavior in adulthood and suggest that the increased brain serotoninergic activity could play a role in this effect.

Heart rate recovery after exercise: relations to heart rate variability and complexity

Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years) during the pre-exercise phase (25 min supine, 5 min standing), during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output) and during the recovery phase (30 min supine). HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase.

Unequal Teeth Widths for Torque Ripple Reduction in Permanent Magnet Synchronous Machines With Fractional-Slot Non-Overlapping Windings

Permanent magnet synchronous machines with fractional-slot non-overlapping windings (FSPMSM), also known as tooth-coil winding permanent magnet synchronous machines (TCW PMSM), have been under intensive research during the latest decade. There are many optimization routines explained and implemented in the literature in order to improve the characteristics of this machine type. This paper introduces a new technique for torque ripple minimization in TCW PMSM. The source of torque harmonics is also described. The low order torque harmonics can be harmful for a variety of applications, such as direct drive wind generators, direct drive light vehicle electrical motors, and for some high precision servo applications. The reduction of the torque ripple harmonics with the lowest orders (6th and 12th) is realized by machine geometry optimization technique using finite element analysis (FEA). The presented optimization technique includes the stator geometry adjustment in TCW PMSMs with rotor surface permanent magnets and with rotor embedded permanent magnets. Influence of the permanent magnet skewing on the torque ripple reduction and cogging torque elimination was also investigated. It was implemented separately and together with the stator optimization technique. As a result, the reduction of some torque ripple harmonics was attained.

Oral triiodothyronine for the prevention of thyroid hormone reduction in adult valvular cardiac surgery

Treatment of non-thyroidal illness by intravenous triiodothyronine (T3) after cardiac surgery causes a disproportional elevation of hormone levels. The administration of oral T3, which has never been studied in this context, could cause physiological hormone levels. The aim of this study was to test oral T3 for the prevention of T3 reduction during the postoperative period of valvular cardiac surgery in adults. Eighteen patients who underwent cardiac surgery for valvular disease with invasive hemodynamic monitoring were randomly assigned to 2 groups: the T group received oral T3 (N = 8), 25 µg three times/day, initiated 24 h before surgery and maintained for 48 h and the NT group (N = 10) received placebo. Serum T3, thyroxine and thyrotropin were determined at baseline, 1 h before surgery, within 30 min of cardiopulmonary bypass and 6, 12, 24, and 48 h after removal of the aortic cross-clamp. Baseline T3 was similar in both groups (T: 119 ± 13; NT: 131 ± 9 ng/dL). Serum T3 increased during the first 24 h in the T group compared to the NT group (232 ± 18 vs 151 ± 13 ng/dL; P < 0.001). In the NT group, T3 was reduced by 24% (P = 0.007) 6 h after removal of the aortic cross-clamp, confirming the non-thyroidal illness syndrome. There were no differences in clinical or hemodynamic parameters between groups. Administration of oral T3 prevented its serum reduction after valvular cardiac surgery in adults, with normal serum levels for 48 h without disproportional elevations.

Learning about brain physiology and complexity from the study of the epilepsies

The brain is a complex system, which produces emergent properties such as those associated with activity-dependent plasticity in processes of learning and memory. Therefore, understanding the integrated structures and functions of the brain is well beyond the scope of either superficial or extremely reductionistic approaches. Although a combination of zoom-in and zoom-out strategies is desirable when the brain is studied, constructing the appropriate interfaces to connect all levels of analysis is one of the most difficult challenges of contemporary neuroscience. Is it possible to build appropriate models of brain function and dysfunctions with computational tools? Among the best-known brain dysfunctions, epilepsies are neurological syndromes that reach a variety of networks, from widespread anatomical brain circuits to local molecular environments. One logical question would be: are those complex brain networks always producing maladaptive emergent properties compatible with epileptogenic substrates? The present review will deal with this question and will try to answer it by illustrating several points from the literature and from our laboratory data, with examples at the behavioral, electrophysiological, cellular and molecular levels. We conclude that, because the brain is a complex system compatible with the production of emergent properties, including plasticity, its functions should be approached using an integrated view. Concepts such as brain networks, graphics theory, neuroinformatics, and e-neuroscience are discussed as new transdisciplinary approaches dealing with the continuous growth of information about brain physiology and its dysfunctions. The epilepsies are discussed as neurobiological models of complex systems displaying maladaptive plasticity.

Pitfalls in the assessment of murine atherosclerosis

This review provides examples of the fact that different procedures for the measurement of atherosclerosis in mice may lead to interpretation of the extent of atherosclerosis having markedly different biological and clinical significance for humans: 1) aortic cholesterol measurement is highly sensitive for the detection of early and advanced atherosclerosis lesions, but misses the identification of the location and complexity of these lesions that are so critical for humans; 2) the histological analysis of the aortic root lesions in simvastatin-treated and control mice reveals similar lesion morphology in spite of the remarkable simvastatin-induced reduction of the aortic cholesteryl ester content; 3) in histological analyses, chemical fixation and inclusion may extract the tissue fat and also shrink and distort tissue structures. Thus, the method may be less sensitive for the detection of slight differences among the experimental groups, unless a more suitable procedure employing physical fixation with histological sample freezing using optimal cutting temperature and liquid nitrogen is employed. Thus, when measuring experimental atherosclerosis in mice, investigators should be aware of several previously unreported pitfalls regarding the extent, location and complexity of the arterial lesion that may not be suitable for extrapolation to human pathology.

Luteinizing hormone reduction by the male potency herb, Butea superba Roxb.

To determine if Butea superba Roxb., a traditional Thai male potency herb, has androgenic activity in 60-day-old male Wistar rats, we measured its effects on the pituitary-testicular axis and sex organs. Intact and orchidectomized adult male rats were subdivided into five groups (10 rats/group): distilled water, Butea superba (BS)-10, BS-50, BS-250, and testosterone propionate (TP). They received 0, 10, 50, and 250 mg·kg body weight-1·day-1 BS in distilled water by gavage and 6 mg·kg body weight-1·day-1 TP sc, respectively, during the 30-day treatment period. Blood was collected every 15 days and luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone were measured. Changes of weight and histological appearance of sex organs were determined at the end of the 30-day treatment and 15-day post-treatment periods. TP treatment reduced serum FSH and LH levels and significantly increased the weight of the seminal vesicles and epididymis, in accordance with histopathological changes, in both intact and orchidectomized rats. No changes in serum testosterone, LH, and FSH levels were observed in any of the intact rats treated with BS, but a significant increase in seminal vesicle weight was observed only in the BS-250 group. Although a significant reduction in serum LH was detected in the BS-50 and BS-250 groups of orchidectomized rats, no significant change in weight or histology of sex organs was observed. Thus, we conclude that B. superba needs endogenous testosterone to work synergistically to stimulate the accessory sex organ of intact animals and can potentially exhibit an LH reduction effect in orchidectomized animals.

Reduction of the amount of intestinal secretory IgA in fulminant hepatic failure

Intestinal barrier dysfunction plays an important role in spontaneous bacterial peritonitis. In the present study, changes in the intestinal barrier with regard to levels of secretory immunoglobulin A (SIgA) and its components were studied in fulminant hepatic failure (FHF). Immunohistochemistry and double immunofluorescent staining were used to detect intestinal IgA, the secretory component (SC) and SIgA in patients with FHF (20 patients) and in an animal model with FHF (120 mice). Real-time PCR was used to detect intestinal SC mRNA in the animal model with FHF. Intestinal SIgA, IgA, and SC staining in patients with FHF was significantly weaker than in the normal control group (30 patients). Intestinal IgA and SC staining was significantly weaker in the animal model with FHF than in the control groups (normal saline: 30 mice; lipopolysaccharide: 50 mice; D-galactosamine: 50 mice; FHF: 120 mice). SC mRNA of the animal model with FHF at 2, 6, and 9 h after injection was 0.4 ± 0.02, 0.3 ± 0.01, 0.09 ± 0.01, respectively. SC mRNA of the animal model with FHF was significantly decreased compared to the normal saline group (1.0 ± 0.02) and lipopolysaccharide group (0.89 ± 0.01). The decrease in intestinal SIgA and SC induced failure of the intestinal immunologic barrier and the attenuation of gut immunity in the presence of FHF.

Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7%), WSS (Wistar/E+: 36; SHR/E+: 40%) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.

Chi-square analysis of the reduction of ATP levels in L-02 hepatocytes by hexavalent chromium

This study explored the reduction of adenosine triphosphate (ATP) levels in L-02 hepatocytes by hexavalent chromium (Cr(VI)) using chi-square analysis. Cells were treated with 2, 4, 8, 16, or 32 μM Cr(VI) for 12, 24, or 36 h. Methyl thiazolyl tetrazolium (MTT) experiments and measurements of intracellular ATP levels were performed by spectrophotometry or bioluminescence assays following Cr(VI) treatment. The chi-square test was used to determine the difference between cell survival rate and ATP levels. For the chi-square analysis, the results of the MTT or ATP experiments were transformed into a relative ratio with respect to the control (%). The relative ATP levels increased at 12 h, decreased at 24 h, and increased slightly again at 36 h following 4, 8, 16, 32 μM Cr(VI) treatment, corresponding to a "V-shaped" curve. Furthermore, the results of the chi-square analysis demonstrated a significant difference of the ATP level in the 32-μM Cr(VI) group (P < 0.05). The results suggest that the chi-square test can be applied to analyze the interference effects of Cr(VI) on ATP levels in L-02 hepatocytes. The decreased ATP levels at 24 h indicated disruption of mitochondrial energy metabolism and the slight increase of ATP levels at 36 h indicated partial recovery of mitochondrial function or activated glycolysis in L-02 hepatocytes.

IL-6 upregulation contributes to the reduction of miR-26a expression in hepatocellular carcinoma cells

A recent study showed that miR-26a is downregulated in hepatocellular carcinoma tissues and that this downregulation is an independent predictor of survival. Interestingly, the same study also reported that miR-26a downregulation causes a concomitant elevation of IL-6 expression. Because miR-26a expression was found to be transcriptionally downregulated by oncogene c-Myc in various cancers, and the expression of c-Myc was increased by IL-6 stimulation, we hypothesized that IL-6 contributes to reduction of miR-26a in hepatocellular carcinoma. Serum IL-6 was measured by ELISA and miR-26a was detected by qRT-PCR. The data of 30 patients with hepatocellular carcinoma who had undergone surgical tumor resection revealed that serum IL-6 could be considered to be a predictor of survival up to 5 years for hepatocellular carcinoma patients (log-rank test, P < 0.05). We observed that the serum IL-6 concentration was inversely correlated with miR-26a expression in cancerous tissues (Pearson correlation test, r = -0.651, P < 0.01). Furthermore, by in vitro experiments with HepG2 cells, we showed that IL-6 stimulation can lead to miR-26a suppression via c-Myc activation, whereas in normal hepatocyte LO2 cells incubation with IL-6 had no significant effect on miR-26a expression. Taken together, these results indicate that miR-26a reduction in hepatocellular carcinoma might be due to IL-6 upregulation.

Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3×107 cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2-ΔΔCT method. FO significantly decreased tumor growth (W=13.18±1.58 vsWFO=5.40±0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1±1.62 vsWFO=59.39±5.53, P<0.001) and PPARγ (W=100.4±1.04vs WFO=88.22±1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06±0.022 vsWFO=0.31±0.04 (P<0.001) for COX-2, W=1.08±0.02vs WFO=0.52±0.08 (P<0.001) for PPARγ, and W=1.04±0.02 vs WFO=0.82±0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.

Early detection of metabolic and energy disorders by thermal time series stochastic complexity analysis

Maintenance of thermal homeostasis in rats fed a high-fat diet (HFD) is associated with changes in their thermal balance. The thermodynamic relationship between heat dissipation and energy storage is altered by the ingestion of high-energy diet content. Observation of thermal registers of core temperature behavior, in humans and rodents, permits identification of some characteristics of time series, such as autoreference and stationarity that fit adequately to a stochastic analysis. To identify this change, we used, for the first time, a stochastic autoregressive model, the concepts of which match those associated with physiological systems involved and applied in male HFD rats compared with their appropriate standard food intake age-matched male controls (n=7 per group). By analyzing a recorded temperature time series, we were able to identify when thermal homeostasis would be affected by a new diet. The autoregressive time series model (AR model) was used to predict the occurrence of thermal homeostasis, and this model proved to be very effective in distinguishing such a physiological disorder. Thus, we infer from the results of our study that maximum entropy distribution as a means for stochastic characterization of temperature time series registers may be established as an important and early tool to aid in the diagnosis and prevention of metabolic diseases due to their ability to detect small variations in thermal profile.

Reduction of blood nitric oxide levels is associated with clinical improvement of the chronic pelvic pain related to endometriosis

The objective of this prospective study was to determine the plasma levels of nitric oxide (NO) in women with chronic pelvic pain secondary to endometriosis (n=24) and abdominal myofascial pain syndrome (n=16). NO levels were measured in plasma collected before and 1 month after treatment. Pretreatment NO levels (μM) were lower in healthy volunteers (47.0±12.7) than in women with myofascial pain (64.2±5.0, P=0.01) or endometriosis (99.5±12.9, P<0.0001). After treatment, plasma NO levels were reduced only in the endometriosis group (99.5±12.9 vs 61.6±5.9, P=0.002). A correlation between reduction of pain intensity and reduction of NO level was observed in the endometriosis group [correlation = 0.67 (95%CI = 0.35 to 0.85), P<0.0001]. Reduction of NO levels was associated with an increase of pain threshold in this group [correlation = -0.53 (-0.78 to -0.14), P<0.0001]. NO levels appeared elevated in women with chronic pelvic pain diagnosed as secondary to endometriosis, and were directly associated with reduction in pain intensity and increase in pain threshold after treatment. Further studies are needed to investigate the role of NO in the pathophysiology of pain in women with endometriosis and its eventual association with central sensitization.