Pulsed processing by cold plasma, applied to industrial emission control.

A promising pollution control technology is cold plasma driven chemical processing. The plasma is a pulsed electric gas discharge inside a near atmospheric-pressure-temperature reactor. The system is energized by a continuous stream of very short high-voltage pulses. The exhaust gas to be treated flows through the reactor. The methods applied involve the development of robust cold plasma systems, industrial applications and measuring technologies. Tests of the systems were performed at many industrial sites and involved control of airborne VOC (volatile organic compound) and odor. Electrical, chemical and odor measuring data were collected with state-of-the-art methods. To explain the test data an approximate solution of global reaction kinetics of pulsed plasma chemistry was developed. It involves the Lambert function and, for convenience, a simple approximation of it. The latter shows that the amount of removal, in good approximation, is a function of a single variable. This variable is electric plasma power divided by gas flow divided by input concentration. In the results sections we show that in some cases up to 99% of volatile pollution can be removed at an acceptable energy requirement. In the final sections we look into future efficiency enhancements by implementation of (sub)nanosecond pulsed plasma and solid state high-voltage technology and by integration with catalyst technology.

[Bronchus insufficiency: prevention and therapy]. / Bronchusinsuffizienz: Prävention und Therapie.

In order to achieve respectable postoperative outcomes after lung resection it is essential to understand the mechanism of bronchus healing. The bronchus seal should be air-tight and consist of monofilament suture or staples. The bronchus suture should be covered with vital tissue (lung, mediastinum, muscle flap). A complication in the process of bronchus healing should be diagnosed as early as possible in order to stop the destructive effect of the infection as rapidly as possible.

[Influence of nosocomial infections on resection of tracheal stenosis after tracheotomy]. / Bedeutung nosokomialer Infektionen bei derResektion trachealer Stenosen nach Tracheotomie.

BACKGROUND: Complications located at the tracheostoma often occur in combination with nosocomial infections. We posed the question: how is the surgical result in tracheal resections influenced by bacterial contamination with multiresistant germs? PATIENTS AND METHODS: Between 2005 and 2009 we performed a primary end-to-end-resection of the trachea after tracheotomy in 30 patients. The demographic basic data, the diagnostic data on tracheal stenosis after decanullation and type of tracheotomy were documented. Preoperatively all patients underwent a flexible bronchoscopy with bronchial lavage. All patients received an antibiotic inhalation therapy postoperatively. RESULTS: 16 patients presented a status post-permanent tracheotomy (PT), in 14 cases after percutaneous dilatative tracheotomy (PDT). In 64 % of all cases the preoperative bronchial lavage was positive for bacterial contamination. The major pathogen was with 23 % a multiresistant Pseudomonas aeruginosa (MR). In three cases long-term-complications occurred, all of which were bacterially contaminated. CONCLUSION: After long-term intubation a bacterial contamination is very common and presents a negative predictor for the outcome of primary tracheal end-to-end resections. A prophylactic postoperative antibiotic therapy can improve the short- and long-term results.

[Pulmonary nodules in underlying malignant diseases--not necessarily metastases of the primary tumour]. / Der pulmonale Rundherd bei maligner Grunderkrankung--nicht zwingend eine Metastase des Primärtumors.

BACKGROUND: In this study the histological examination of pulmonary nodules and a comparison of the number of pre-, intra- and post-operative lung metastases in patients with a previous history of malignant disease were assessed. PATIENTS AND METHODS: Between 1998 and 2003 we operated on 276 patients with suspected lung metastases. The histology of the primary tumour, the number of preoperatively diagnosed nodules, the number of lesions removed during surgery and the number of histologically confirmed metastases of 276 patients are presented. RESULTS: In 276 patients a resection was performed. 161 of the patients were men (58.1%). The median age was 62 years (range: 21-86 years). In 110 cases a left-sided thoracotomy was performed (39.8%), in another 110 cases a right-sided thoracotomy was performed and in 56 cases we performed a bilateral thoracotomy (20.4%). In 15.2% the histology of the resected nodules was benign. In 8.6% of the cases the histological examination showed a primary lung cancer in stage I, in 74.4% of the cases the histology confirmed a metastasis of the primary cancer. CONCLUSIONS: Solitary pulmonary nodules in patients with a previous history of malignant disease should always be resected for histological examination. Multiple pulmonary nodules should be histologically reappraised if there is any doubt about the entity.

The effect of pressure on the electrical breakdown in the membranes of Valonia utricularis.

The interpretation of electrical breakdown in terms of electro-mechanical instabilities, predicts that the breakdown potential should decrease with increasing cell turgor pressure. Experiments were conducted to test this hypothesis on cells of Valonia utricularis over a turgor pressure range of 0.5-10(5)-5.0-10(5) N/m2. Electrical breakdown was measured using intracellular electrodes and 500 mus current pulses. The pressure was monitored by an intracellular micropipette pressure transducer. The results obtained show a linear decrease in the critical breakdown potential with pressure. The effective compressive modulus of the cell membrane, gamma, is calculated from the slope of this line to 69+/-10-10(5) N/m2 (average value of seven measurements). This is consistent with the theoretical prediction of the electromechanical model using our previously determined values of the elastic modulus of the membrane. A theoretical analysis is given of the effects of pressure on the breakdown, This includes also considerations of the indirect effect of pressure on the membrane via stretching of the cell wall with a possible coupling of such strains to the cell membrane. The results and analysis presented allow us to conclude on the basis of the experimentally determined breakdown P.K. of 959 mV that the region of membrane where electrical breakdown occurs is a dielectric with one of the following combinations of parameters: (A) a thickness delta=7-9 nm with a dielectric constant epsilon=greater than 10, e.g. a hydrated protein spanning the whole membrane. (B) delta=4-5 nm with epsilon=3-8, e.g. a lipoprotein of lipid bilayer dimensions. (C) delta approximately 2 nm with epsilon=2-3, e.g. a half lipid bilayer. If we assume that the breakdown P.D. of the tonoplast and plasmalemma are identical, that is 480 mV, then there is only one reasonable choice for the membrane thickness and the dielectric constant: delta=2 nm, epsilon=3-8, e.g. a (lipo) proteinaceous module facing a half life lipid bilayer.

Zinc regulation of insulin-like growth factor-I (IGF-I), growth hormone receptor (GHR) and binding protein (GHBP) gene expression in rat cultured hepatocytes.

Dietary zinc depletion in vivo attenuates growth, decreases circulating insulin-like growth factor-I (IGF-I) and liver growth hormone (GH) receptors (GHR). In order to investigate a direct role of zinc in the regulation of IGF-I, GHR and GH binding protein (GHBP) gene expression, we evaluated the response of their mRNAs to changes in zinc availability in primary culture of rat hepatocytes. Exposition of cells to the zinc chelator DTPA (diethylenetriaminepenta-acetic acid) did not decrease IGF-I and GHBP mRNAs while it strongly inhibited metallothionein (MT) gene expression. On the other hand, zinc excess (50 vs. 1.5 microM) decreased IGF-I, GHR and GHBP mRNAs while it stimulated MT mRNA. However, the response of IGF-I to GH was not affected by the exposure to DTPA nor zinc excess. Furthermore, zinc repletion of primary cultured hepatocytes isolated from zinc-deprived rats did not increase IGF-I nor GHR/GHBP mRNAs. Therefore, our results suggest that the IGF-I decline induced in vivo by zinc deficiency is not caused by reduced extracellular zinc availability at the hepatocyte level. Although IGF-I and MT gene expression is down-regulated by dietary zinc depletion, underlying mechanisms of regulation are different for both genes.

Wavelet decomposition analysis of heart rate variability in aerobic athletes.

Heart rate variability (HRV) can be quantified, among others, in the frequency domain using digital signal processing (DSP) techniques. The wavelet transform is an alternative tool for the analysis of non-stationary signals. The implementation of perfect reconstruction digital filter banks leads to multi resolution wavelet analysis. Software was developed in LabVIEW. In this study, the average power was compared at each decomposition level of a tachogram, containing the consecutive RR-intervals of two groups of subjects: aerobic athletes and a control group. Compared to the controls, the aerobic athletes showed an increased power in all frequency bands. These results are in accordance with values obtained by spectral analysis using the Fourier transform, suggesting that wavelet analysis could be an appropriate tool to evaluate oscillating components in HRV, but in addition to classic methods, it also gives a time resolution.

Analysis of heart rate variability with correlation dimension method in a normal population and in heart transplant patients.

INTRODUCTION: The correlation dimension (CD) method is related to chaos theory and is used to quantify heart rate variability (HRV). The CD is a measure for the amount of correlations present in the signal. METHODS: The algorithm used to calculate the CD is based on the method of Grassberger and Proccacia. The method was first validated on signals with known CD and then applied to HRV-signals of heart transplants and an age-matched control group of healthy subjects. The CD of the corresponding surrogate time series was calculated to investigate non-linear correlations in the HRV-signal. Circadian variations of the CD were studied in 20 healthy subjects, including men and women. RESULTS: The value of the CD for healthy subjects ranged from 2.12 to 5.53 with a mean value of 4.32. For heart transplants, only a few time series showed a finite value of the CD that varied between 2.10 and 5.60. Also, a significant difference was found between the CD of the original and the surrogate time series in healthy subjects. The CD of women is higher than the CD of men, and this difference was more pronounced during the night than during the day. CONCLUSIONS: This limited study shows that the CD alone cannot be used to make a distinction between HRV-signals of healthy subjects and of heart transplants. However, there is evidence that there are non-linear correlations present in the HRV-signal and that there are significant gender and circadian differences in the CD.

Continuous profiles and within-day variations of metabolites and hormones in cows fed diets varying in alimentary supplies before short-term feed deprivation.

We investigated continuous profiles and within-day variations of some metabolites and hormones in four nonpregnant, nonlactating cows fed hay-based diets in two equal meals. Diets supplied either too much or too little N (approximately 1.3 or .8 times the maintenance requirements) and NE1 (approximately 1.2 or .8 times). Continuous collection of ruminal liquor, blood, and urine samples was performed for 42 consecutive hours, the last 16 h covering a period without feed. For twice-daily feeding, nitrogenous and energetic underfeeding decreased average ruminal propionate and the insulin:growth hormone ratio. However, only the energetic underfeeding increased plasma 3-methylhistidine and urinary excretion of 3-methylhistidine, and decreased body weight and ruminal acetate, butyrate, and total VFA. Conversely, only the nitrogenous underfeeding decreased glycemia. Whatever the dietary level, the 42-h patterns of metabolites and hormones were mainly affected by the time from the last meal. An energy deficit progressively took place during feed deprivation and the nocturnal interprandial period but not during the diurnal interprandial period. During the feed deprivation and nocturnal periods, glycemia was maintained despite a shortage in ruminal propionate. We conclude that in twice-daily fed cattle 1) the dietary supply of energy is the main trigger for an energy deficit and the subsequent muscle protein mobilization; 2) the nocturnal interprandial period may be considered as short-term feed deprivation; 3) the diurnal patterns of metabolites and hormones are not affected by the nitrogenous and(or) energetic supplies of the diet.

The analysis of heart rate variability in unrestrained rats. Validation of method and results.

An experimental setting and software were developed to evaluate cardiac autonomic function in unrestrained rats. Subcutaneously implanted ECG electrodes and an indwelling venous catheter were tunneled to a tail cuff in five rats. The ECG was A/D converted at 1000 Hz. After peak detection, a time series of RR intervals was obtained. Programs for the analysis of heart rate variability (HRV) were implemented in LabVIEW. Statistical properties were determined in the time domain. After cubic spline function curve fitting, resampling at 0.1 s and test for stationarity, power spectral analysis was performed on sampled records of 30 min duration after applying a sliding Hanning window (Welch method: 256 points (duration 25.6 s), 50% overlap and 0.039 Hz resolution). Algorithms were tested with simulated signals consisting of isolated frequency components, which were retrieved at their exact locations. Physiological validation of the system was performed by, beta-adrenergic and cholinergic blockade and by forced breathing at a fixed rate. Measurements were performed on five unrestrained rats under basal conditions. Mean RR was 174.2 +/- 3.6 ms; S.D., 13.3 +/- 4.6 ms; rMSSD, 5.2 + /- 1.2 ms; pNN10, 3.5 +/- 1.9% and pNN5, 18.7 +/- 6.4%. Low (0.19-0.74 Hz) and high frequency (0.78-2.5 Hz) power were determined (and also percent of low to total and high to total): 18.42 +/- 10.74 ms2 (22.9 +/- 6.5%) and 15.66 +/- 5.56 ms2 (19.9 +/- 2.7%), and the ratio low/high: 1.16 +/- 0.39. In conclusion, HRV analysis programs were developed and thoroughly tested through simulations and in vivo, under basal conditions and after pharmacological blockades. Using this software, HRV data from unrestrained rats were obtained.

Operational point of neural cardiovascular regulation in humans up to 6 months in space.

Entering weightlessness affects central circulation in humans by enhancing venous return and cardiac output. We tested whether the operational point of neural cardiovascular regulation in space sets accordingly to adopt a level close to that found in the ground-based horizontal position. Heart rate (HR), finger blood and brachial blood pressure (BP), and respiratory frequency were collected in 11 astronauts from nine space missions. Recordings were made in supine and standing positions at least 10 days before launch and during spaceflight (days 5-19, 45-67, 77-116, 146-180). Cross-correlation analyses of HR and systolic BP were used to measure three complementary aspects of cardiac baroreflex modulation: 1) baroreflex sensitivity, 2) number of effective baroreflex estimates, and 3) baroreflex time delay. A fixed breathing protocol was performed to measure respiratory sinus arrhythmia and low-frequency power of systolic BP variability. We found that HR and mean arterial pressure did not differ from preflight supine values for up to 6 mo in space. Respiration frequency tended to decrease during prolonged spaceflight. Concerning neural markers of cardiovascular regulation, we observed in-flight adaptations toward homeostatic conditions similar to those found in the ground-based supine position. Surprisingly, this was not the case for baroreflex time delay distribution, which had somewhat longer latencies in space. Except for this finding, our results confirm that the operational point of neural cardiovascular regulation in space sets to a level close to that of an Earth-based supine position. This adaptation level suggests that circulation is chronically relaxed for at least 6 mo in space.

Estimating the direct impact of new conjugate vaccines against invasive pneumococcal disease.

New pneumococcal conjugate vaccines (PCVs) are now becoming available. These formulations differ from the heptavalent diphtheria toxin variant conjugate vaccine (7vCRM, Prevenar/Prevnar) both in the number of serotypes and in serotype-specific immunogenicity. This review proposes an algorithm that attempts to predict the overall impact of these differences in vaccine formulation and immunogenicity on invasive pneumococcal disease (IPD) effectiveness. It builds on the principles underlying WHO licensure criteria for new PCVs, that serotype-specific anti-polysaccharide immunogenicity is potentially predictive of effectiveness. The algorithm used three sources of information: serotype-specific effectiveness data for 7vCRM, serotype-specific head-to-head immunogenicity data with 7vCRM and a recently licensed 10-valent pneumococcal non-typeable H. influenzae protein D-conjugate vaccine (PHiD-CV, Synflorix), and epidemiological information regarding the serotypes causing IPD in young children. Based on this algorithm, PHiD-CV and 7vCRM are predicted to prevent approximately 60-80% and 45-80%, respectively of IPD in young children worldwide, with significant variability by country and region.

Effect of 35 years beta-adrenergic blockade therapy on autonomic cardiovascular modulation. A case study.

The influence of long duration beta-blockade on autonomic and cardiovascular function remains not completely understood. The aim of this study was to evaluate the effect of long duration beta-adrenergic blockade treatment for hypertension control, on autonomic cardiovascular control in a 78-year-old male patient in relation to population findings. Heart rate variability was determined in the frequency domain (Total power, low frequency power and high frequency power), during baseline (supine and standing) and during 24 hour Holter recording. Results were compared with heart rate and heart rate variability data obtained from a normal healthy male population as a function of age. Circadian rhythm remained present. Heart rate during daytime was lower compared to the population group. None of the heart rate variability parameters were different from the normal population age group. Our results show that after 35 years of beta-blockade treatment, autonomic modulation of cardiac function remains within normal limits for that age group. Blood pressure remained at the higher limits (120-150/60-80 mmHg), but under control.

Respiratory modulation of cardiovascular rhythms before and after short-duration human spaceflight.

AIM: Astronauts commonly return from space with altered short-term cardiovascular dynamics and blunted baroreflex sensitivity. Although many studies have addressed this issue, post-flight effects on the dynamic circulatory control remain incompletely understood. It is not clear how long the cardiovascular system needs to recover from spaceflight as most post-flight investigations only extended between a few days and 2 weeks. METHODS: In this study, we examined the effect of short-duration spaceflight (1-2 weeks) on respiratory-mediated cardiovascular rhythms in five cosmonauts. Two paced-breathing protocols at 6 and 12 breaths min(-1) were performed in the standing and supine positions before spaceflight, and after 1 and 25 days upon return. Dynamic baroreflex function was evaluated by transfer function analysis between systolic pressure and the RR intervals. RESULTS: Post-flight orthostatic blood pressure control was preserved in all cosmonauts. In the standing position after spaceflight there was an increase in heart rate (HR) of approx. 20 beats min(-1) or more. Averaged for all five cosmonauts, respiratory sinus dysrhythmia and transfer gain reduced to 40% the day after landing, and had returned to pre-flight levels after 25 days. Low-frequency gain decreased from 6.6 (3.4) [mean (SD)] pre-flight to 3.9 (1.6) post-flight and returned to 5.7 (1.3) ms mmHg(-1) after 25 days upon return to Earth. Unlike alterations in the modulation of HR, blood pressure dynamics were not significantly different between pre- and post-flight sessions. CONCLUSION: Our results indicate that short-duration spaceflight reduces respiratory modulation of HR and decreases cardiac baroreflex gain without affecting post-flight arterial blood pressure dynamics. Altered respiratory modulation of human autonomic rhythms does not persist until 25 days upon return to Earth.

Influence of supplemental magnesium, tryptophan, vitamin C, and vitamin E on stress responses of pigs to vibration.

Our objectives were to investigate and compare the effects of supplemental Mg, Trp, vitamin E (vit E), and vitamin C (vit C) on stress responses of pigs undergoing transport simulation. In this study, 126 pigs (25.1 +/- 4.4 kg BW) were allocated to one of the six following treatments: 1) negative control (no supplementation); 2) positive control (i.m. injection with 0.5 mg of carazolol/20 kg BW 12 h before vibration, beta-blocker); 3) Trp (additional amount of 6 g/kg of feed for 5 d, as-fed basis); 4) Mg (3 g/L drinking water for 2 d); 5) vit E (additional amount of 150 mg/kg of feed for 21 d, as-fed basis); 6) or vit C (additional amount of 300 mg/kg of feed for 21 d, as-fed basis). Pigs were treated in groups of three, and each treatment was replicated seven times. Feed and water intake were not different among treatments. Heart rate variables (mean, peak, and minimum heart rate, ventricular ectopic beats, and ST elevation of Channels A and B) and heart rate variability were registered from the night before vibration. Pigs were subjected to vibration in a transport simulator (8 Hz, 3 m/s) for 2 h and allowed to recover for 2 h. Generally, the positive control pigs had the lowest heart rate values (mean, peak, minimum heart rate, ST elevation of Channel A; P < 0.05), whereas Mg and Trp decreased ventricular ectopic beats and ST elevation of Channel B, respectively. The effect of vit C and E as vagal stimulators was clearly visible, whereas carazolol and Mg clearly blocked the sympathetic pathways of the autonomic nervous system. During vibration, the negative control pigs lay the least, and Mg pigs the most (P < 0.05). Salivary cortisol concentrations (taken before and after vibration and after recovery) showed that vit E pigs produced the least cortisol during stress periods. Intermediary metabolites (glucose, lactate, creatine kinase, and NEFA) were analyzed in plasma from blood taken before and after vibration. At the two sampling points, the vit E and Mg pigs had the lowest NEFA concentrations (P < 0.05), and the vit E pigs also had the lowest lactate concentrations before vibration. Urine samples were collected before and after vibration to determine catecholamine concentrations; only negative control pigs had an increase (P = 0.04) in epinephrine concentration, despite large individual variation. In general, these results indicate that the supplementation of Trp, Mg, vit E, or vit C improved coping ability of pigs during vibration comparison with the negative control treatment. A muscular injection of carazolol influenced only the heart rate variables.

Generation of action potentials in Chara corallina by turgor pressure changes.

A depolarisation of the membrane potential difference (about-170 mV) of Chara corallina is observed in response to changes in cell turgor pressure using the pressure probe technique. The depolarisation occurs in phase with the pressure pulse (0.2 s duration) and is independent of the direction of the applied pressure gradient. This latter finding is in contradiction to results predicted on the basis of electro-kinetic phenomena. Pressure induced electrical leakages were ruled out by measuring the depolarisation in response to pressure in individual segments of the internode which were electrically isolated from one another. The changes in potential were recorded by external electrodes and an internal electrode which was positioned close to the micropipette of the pressure probe inserted through one of the electrically isolated nodes. The depolarisation in response to increasing positive or negative pressure gradients in the intact node region and in the intact middle segments was comparable to that monitored in the node region containing the pressure probe. Action potentials were initiated when the pressure gradients exceeded at least 2 bar. The action potentials were elicited at random in one of the two compartments adjacent to the node regions, but were never found to be initiated in the node regions themselves. The pressure-induced action potentials are explained in terms of an electro-mechanical compression (or expansion) of a local membrane area and discussed in their relevance to the propagation of pressure signals in response to water and salt stress in higher plants.

Reversible electrical breakdown of lipid bilayer membranes: a charge-pulse relaxation study.

Charge-pulse experiments were performed with lipid bilayer membranes from oxidized cholesterol/n-decane at relatively high voltages (several hundred mV). The membranes show an irreversible mechanical rupture if the membrane is charged to voltages on the order of 300 mV. In the case of the mechanical rupture, the voltage across the membrane needs about 50-200 musec to decay completely to zero. At much higher voltages, applied to the membrane by charge pulses of about 500 nsec duration, a decrease of the specific resistance of the membranes by nine orders of magnitude is observed (from 10(8) to 0.1 omega cm2), which is correlated with the reversible electrical breakdown of the lipid bilayer membrane. Due to the high conductance increase (breakdown) of the bilayer it is not possible to charge the membrane to a larger value than the critical potential difference Vc. For 1 M alkali ion chlorides Vc was about 1 V. The temperature dependence of the electrical breakdown voltage Vc is comparable to that being observed with cell membranes. Vc decreases between 2 and 48 degrees C from 1.5 to 0.6 V in the presence of 1 M KCl. Breakdown experiments were also performed with lipid bilayer membrane composed of other lipids. The fast decay of the voltage (current) in the 100-nsec range after application of a charge pulse was very similar in these experiments compared with experiments with membranes made from oxidized cholesterol. However, the membranes made from other lipids show a mechanical breakdown after the electrical breakdown, whereas with one single membrane from oxidized cholesterol more than twenty reproducible breakdown experiments could be repeated without a visible disturbance of the membrane stability. The reversible electrical breakdown of the membrane is discussed in terms of both compression of the membrane (electromechanical model) and ion movement through the membrane induced by high electric field strength (Born energy).

[Doppler sonography in phlebological diagnosis]. / Doppler-Sonographie in der phlebologischen Diagnostik.

Doppler-sonography is a helpful new technique in clinical phlebological diagnosis. The method can be used for measuring systolic blood pressure of ankle arteries, for examination of venous function as well as for the evaluation of venous occlusion. By calculating the systolic pressure gradient between arm and ankle arteries peripheral arterial diseases can be detected and evaluated regarding clinical severity. In diagnosis of venous diseases the normal blood flow signal in the femoral vein--i.e. expiratory flow and inspiratory stop--are compared to pathological findings. If there is venous occlusion, a continuous flow signal will be registered. The method is most reliable in detecting thrombosis of the deep pelvic and femoral veins. Venous thrombosis of the calf cannot be diagnosed at the moment. Venous valvular insufficiency leads to a continuous flow signal during Valsalva's pressing manoeuvre. The method is limited by the fact that functional, but not morphological parameters are registered.

Realized heritability of longevity in Drosophila melanogaster.

From the data of an experiment of selection for increased longevity, a realized heritability of longevity was calculated. The low value of this heritability (3.4%) was very close to values observed in other experiments concerning Drosophila melanogaster wild strains. The error variance of the heritability estimator was calculated through the use of orthogonal contrasts. In this way, it was possible to calculate the confidence interval of the realized heritability. The amplitude of this interval was wide although the size of the sample was large. This shows the difficulty of estimating with precision the heritability of longevity from data obtained in selection experiments.