In addition, the effect of timing of paracetamol intake was inves

In addition, the effect of timing of paracetamol intake was investigated. In two randomized, controlled, open-label studies 496 healthy young adults were randomly assigned to three groups. The study groups received paracetamol for 24 hours starting at the time of (prophylactic use) – or 6 hours after (therapeutic use) the primary (0 month) and first booster (1 month) hepatitis B vaccination. The control group received no paracetamol. None of the participants used paracetamol around the second

booster (6 months) vaccination. Anti-HBs levels were measured prior to and one month after the second booster vaccination on ADVIA Centaur XP. GDC-0068 chemical structure One month after the second booster vaccination, the anti-HBs level in the prophylactic paracetamol group was significantly lower (p = 0.048) than the level in the control group (4257 mIU/mL selleck chemicals llc vs. 5768 mIU/mL). The anti-HBs level in the therapeutic paracetamol group (4958 mIU/mL) was not different (p = 0.34) from the level in the control group. Only prophylactic paracetamol treatment, and not therapeutic treatment, during vaccination has a negative influence on the antibody concentration after hepatitis B vaccination in adults. These findings prompt to consider therapeutic instead of prophylactic treatment to ensure maximal vaccination efficacy and retain the possibility to treat pain and fever after vaccination.”
“Dental fluorosis

is characterized by subsurface hypomineralization and retention of enamel matrix proteins. Fluoride (F-) exposure generates reactive oxygen species (ROS) that can cause endoplasmic reticulum (ER)-stress. We therefore screened oxidative stress arrays to identify genes regulated by F-

exposure. Vitamin E is an antioxidant so we asked if a diet high in vitamin E would attenuate dental fluorosis. Maturation stage incisor enamel organs (EO) were harvested from F–treated rats and mice were assessed to determine if vitamin E ameliorates dental fluorosis. Uncoupling protein-2 (Ucp2) was significantly up-regulated by F- (similar to 1.5 & 2.0 fold for the 50 or 100ppm F- treatment groups, respectively). Immunohistochemical results on maturation stage rat incisors demonstrated that UCP2 protein levels increased with F- treatment. UCP2 down-regulates mitochondrial production of ROS, which decreases ATP production. Thus, in addition to reduced protein translation caused by ER-stress, a reduction in ATP production SYN-117 by UCP2 may contribute to the inability of ameloblasts to remove protein from the hardening enamel. Fluoride-treated mouse enamel had significantly higher quantitative fluorescence (QF) than the untreated controls. No significant QF difference was observed between control and vitamin E-enriched diets within a given F- treatment group. Therefore, a diet rich in vitamin E did not attenuate dental fluorosis. We have identified a novel oxidative stress response gene that is up-regulated in vivo by F- and activation of this gene may adversely affect ameloblast function.

In contrast, removal of high heterotachous genes from data sets i

In contrast, removal of high heterotachous genes from data sets is simple and can increase confidence in evaluating the phylogeny of gymnosperms.”
“Introduction: the presence of menstrual disorder is very frequent PLX3397 cost complain in adolescence age. Our purpose of this study is to appoint, prevalence the menstrual disorder and

relation between it and anexity disorder.\n\nMethod: This cross sectional study was done on 1200 girl’s school that lived in city or suburb in north of ran. We selected our samples randomly. We collected data with questionnaire for evaluate menstrual disorder & zank questionnaire. Analysis of data was done by SPSS software and we used descriptive statistics, chi- test and in depended T test. Significant level of this study was 0.05.\n\nResult: The prevalence of menstrual disorder in urban girls Nutlin-3 mw was 13/2% and in rural girls was 8.6%. According to chi- test we can say there is meaning full relation between menstrual disorder and location of life.(p=0.02) Menorrhagiawas the common disorder and relation between oligomenorrhea (p=0.032), metrorrhagia (p=0.000), menorragia (p=0.009) was meaning full.\n\nConclusion: menstrual disorder is common in adolescence

age and anxiety is effective on some kind of menstrual disorder.”
“Objectives: To develop Turkish League Against Rheumatism (TLAR) National Recommendations for the management of ankylosing spondylitis (AS).\n\nMaterials and methods: A scientific committee of 25 experts

consisting of six rheumatologists and 19 physical medicine and rehabilitation specialists was formed by TLAR. Recommendations were based on the 2006 ASsessment in Ankylosing Spondylitis International Working Group(ASAS)/European League Against Rheumatism (EULAR) recommendations and a systematic review of associated publications between January 2005 and September 2010. A Delphi process was used selleck screening library to develop the recommendations. Twelve major recommendations were constructed for the management of AS. Voting using a numerical rating scale assessed the strength of each recommendation.\n\nResults: The 12 recommendations include patient assessment, patient follow-up along with pharmacological and non-pharmacological methods. Some minor additions and changes have been made to the ASAS/EULAR recommendations. All of the recommendations had sufficient strength.\n\nConclusion: National recommendations for the management of AS were developed based on scientific evidence and consensus expert opinion. These recommendations will be updated regularly in accordance with recent developments.”
“Gonadotropin analogs like leuprolide play an important role in the management of prostate cancer. Pituitary apoplexy has been reported after leuprolide therapy. This report examines whether the presence of a pituitary tumor is a contraindication for leuprolide therapy in patients with prostate cancer.

004) No consistent effect of GI was seen and the MetS scores wer

004). No consistent effect of GI was seen and the MetS scores were not affected. In conclusion increased protein intake improved cardiovascular markers in high-risk children, particularly in those undergoing most intensive intervention.”
“Neural stem cells (NSCs) raised the hope for cell-based therapies in

human neurodevelopmental and neurodegenerative diseases. Current research strategies aim to isolate, enrich, and propagate homogeneous populations of neural stem cells. Unfortunately, several concerns with NSC cultures currently may limit their therapeutic promise. Exhaustion of growth factors and/or their uncontrolled release with burst and fall in their concentration may greatly affect the in vitro behavior S63845 in vitro of NSCs. In this context, we investigate whether a device containing AC220 mw heparan sulfate (HS), which is a co-factor in growth factor-mediated cell proliferation and differentiation, could potentiate and prolong the delivery of fibroblast growth factor-2 (FGF-2) and thus improve in vitro NSC cultivation. We demonstrated that NSCs cultivated in media with a controlled release of FGF-2 from a polyelectrolyte polymer

showed a higher proliferation rate, and reduced apoptosis and senescence. In these experimental conditions NSCs preserve their stemness properties for a longer period of time compared with controls. Also of interest is that cell fate properties are conserved as well. The controlled release of FGF-2 reduced the level of oxidative stress and this is associated with a lower level of damaged DNA. This result may explain the reduced level of senescence and apoptosis in NSCs cultivated in the presence of hydrogel-releasing FGF-2. (C) 2012 Published by Elsevier B.V.”
“Background: Patients with chronic heart failure (HF) and their partners face many challenges associated with heart disease. High social support in a close relationship has been found to improve survival in patients with HF. However, caring for a patient with HF may have negative effects on the health-related quality of life (HRQOL)

selleck chemicals of the partner responsible for the care. The main focus in health care is still on improving patients’ HRQOL, but the awareness of partners’ and families’ role and situation is increasing. Therefore, further studies are needed to clarify these issues and the importance of partners in relation to HRQOL of patients with HF. Objectives: To describe and compare HRQOL, quality-adjusted life-year (QALY) weights, symptoms of depression, and perceived control and knowledge in patients with chronic HF and their partners and to compare HRQOL and QALY weights in the partners with an age-and sex-matched group. Methods: Data were collected from 135 patient-partner dyads at 2 Swedish hospitals. Data on the reference group were collected from the same region. Results: Patients had lower HRQOL in all dimensions (P < .

Several of the polymer degradation genes are located in close ass

Several of the polymer degradation genes are located in close association with genes for TonB-dependent receptors and transducers, suggesting an integrated regulation of adhesion and degradation of polymers. This confirmed the role of this abundant group of marine bacteria as degraders of particulate matter. Marine Bacteroidetes had a significantly

larger number of proteases than GHs, while non-marine Bacteroidetes had equal numbers of both. Proteorhodopsin containing Bacteroidetes shared two characteristics: small genome size and a higher number of genes involved in CO2 fixation per Mb. The latter may be important in order to survive when floating freely in the illuminated, but nutrient-poor, ocean surface. The ISME Journal (2013) 7, 1026-1037; doi:10.1038/ismej.2012.169; G418 clinical trial AZD3965 published

online 10 January 2013″
“After more than two decades of AIDS epidemic, the spectrum of HIV-associated vascular diseases has mainly evolved from infectious and inflammatory vasculitides to premature atherosclerosis, its related contributing conditions (metabolic syndrome, dyslipidemia, insulin resistance syndrome) and complications (acute coronary and cerebrovascular syndromes). Today, as the AIDS epidemic further progress worldwide and as the life expectancy of HIV-infected patients treated with effective antiviral regimens has dramatically increased, more than 10% of patients experience cardiovascular manifestations. The complex interplay between viral infection, inflammatory and cytokines pathways, protease inhibitors-induced hyperlipidemia and direct effects on endothelial cells has not, by far, been integrated in a single comprehensive pathogenesis Selleck Compound C network. However, recognition of its main components has resulted in a broader appreciation of cardiovascular risk and risk factors in HIV-infected/treated patients.\n\nCardiovascular prevention is required in more than one half of HIV-infected/treated patients to achieve a reliable effectiveness

of modern antiretroviral therapy. As the prognosis of HIV patients improves continuously, this rate is also likely to increase in the future. (c) 2008 Elsevier Ireland Ltd. All rights reserved.”
“Hydraulic conductance of leaves (Kleaf) typically decreases with increasing water stress and recent studies have proposed different mechanisms responsible for decreasing Kleaf. We measured Kleaf concurrently with ultrasonic acoustic emissions (UAEs) in dehydrating leaves of several species to determine whether declining Kleaf was associated with xylem embolism. In addition, we performed experiments in which the surface tension of water in the leaf xylem was reduced by using a surfactant solution.

Characterizing fire behavior under different fuel relationships p

Characterizing fire behavior under different fuel relationships provides insights for natural ecological processes, management strategies for fire mitigation, and positive and negative features of different modeling systems. A comparison of flame length, rate of spread, crown fire activity, and burn probabilities modeled with FlamMap shows some similar patterns across the landscape from all three data sources, but there are potentially important differences. All data sources showed an expected range of

fire behavior. Average flame lengths ranged between 1 and 1.4 m. Rate of spread varied the greatest with a range of 2.4-5.7 m min(-1). Passive crown fire was predicted for 5% of the study area using FCCS and LANDFIRE while passive crown fire was not predicted using SWRA data. No active crown fire BAY 63-2521 was predicted regardless of the data source. Burn probability patterns across the landscape were similar but probability was highest using SWRA and lowest using FCCS. Published by Elsevier

B.V.”
“For both children and adults with neurological, neurodevelopmental, medical, or psychiatric disorders, neuropsychological assessment can be a valuable tool in determining diagnosis, prognosis, and functional abilities as well as informing clinical management. This review summarizes the contributions of neuropsychological assessment to clinical care across diagnostic categories, with the goal of helping clinicians determine its utility for individual patients.”
“A dynamic and heterogeneous

species abundance Duvelisib model generating the lognormal species JAK inhibitor abundance distribution is fitted to time series of species data from an assemblage of stoneflies and mayflies (Plecoptera and Ephemeroptera) of an aquatic insect community collected over a period of 15 years. In each year except one, we analyze 5 parallel samples taken at the same time of the season giving information about the over-dispersion in the sampling relative to the Poisson distribution. Results are derived from a correlation analysis, where the correlation in the bivariate normal distribution of log abundance is used as measurement of similarity between communities. The analysis enables decomposition of the variance of the lognormal species abundance distribution into three components due to heterogeneity among species, stochastic dynamics driven by environmental noise, and over-dispersion in sampling, accounting for 62.9, 30.6 and 6.5% of the total variance, respectively. Corrected for sampling the heterogeneity and stochastic components accordingly account for 67.3 and 32.7% of the among species variance in log abundance. By using this method, it is possible to disentangle the effect of heterogeneity and stochastic dynamics by quantifying these components and correctly remove sampling effects on the observed species abundance distribution.


“Background Previous studies suggested that mechanical


“Background Previous studies suggested that mechanical

intervention during early reperfusion, or ischemia postconditioning (IPo), could protect kidneys against renal ischemia reperfusion injury (RIRI). However, the mechanisms responsible for this protection remain unclear. This study therefore investigated the protection afforded by IPo in rat kidneys in vivo, and the roles of mitochondrial K(ATP) channels (mitoK(ATP)) and mitochondrial permeability transition pores (MPTPs), by inhibiting mitoK(ATP) with 5-hydroxydecanoate (5-HD), and by directly detecting open MPTPs using calcein-AM and CoCl(2).\n\nMethods Thirty-five male Sprague-Dawley rats were randomly assigned to sham-operation (S), ischemia-reperfusion (I/R), IPo, ischemia reperfusion with 5-HD (I/R+5-HD), or IPo with 5-HD (IPo +5-HD) groups. Rats in each group were BI 2536 mouse sacrificed after 6 hours of reperfusion by heart exsanguination or cervical dislocation under anesthesia. RIRI was assessed by determination of creatinine and blood urea nitrogen (BUN), and by examination of histologic sections. The roles of mitoK(ATP) and MPTP were investigated by analyzing fluorescence intensities of mitochondria, mitochondrial membrane potential, intracellular reactive oxygen species (ROS) and intracellular calcium, using

appropriate GSK923295 fluorescent markers. The relationship between apoptosis and RIRI was assessed by determining the apoptotic index (Al) of kidney tubular epithelial cells.\n\nResults The RIRI model was shown to be successful. Significantly higher levels of creatinine and BUN, and abnormal pathology of histologic

sections, were observed in group I/R, compared with group S. 5-HD eliminated the renoprotective effects of IPo. Mitochondrial and mitochondrial membrane potential fluorescence intensities increased, and intracellular calcium, ROS fluorescence intensities and Al decreased in group IPo, compared with group I/R. However, mitochondrial and JQ1 cell line mitochondrial membrane potential fluorescence intensities decreased, and intracellular calcium and ROS fluorescence intensities and Al increased in group IPo+5-HD, compared with group IPo.\n\nConclusions mitoK(ATP) and MPTPs participated in IPo-induced renoprotective mechanisms in rat kidneys subjected to RIRI, possibly through decreased renal tubular epithelial cell apoptosis. Chin Med J 2011;124(14):2191-2195″
“In a continuous anaerobic-anoxic-aerobic (A(2)O) process treating domestic wastewater at ambient temperatures, nitritation was achieved through a combination of short aerobic actual hydraulic retention time (AHRT) and low dissolved oxygen (DO) levels (0.3-0.5 mg/L). The nitrite accumulation rate was about 90% and ammonia removal efficiency was over 95%. With respect to total nitrogen removal, nitritation-denitritation at low DO levels of 0.3-0.5 mg/L was essentially equal to the complete nitrification-denitrification at DO levels of 1.5-2.5 mg/L with the addition of external carbon sources.

Data were drawn from consenting wait-list and primary-care sample

Data were drawn from consenting wait-list and primary-care samples, which potentially over-represented mild-to-moderate cases of depression. Considering reported rates of spontaneous remission, a short untreated period seems defensible for this subpopulation, where judged appropriate by the clinician. Conclusions may not apply to individuals with more severe depression.”
“To assess the time interval required to reach a new steady state of oxygenation-, ventilation-,

Alvocidib concentration respiratory mechanics- and hemodynamics-related variables after decreasing/increasing positive end expiratory pressure (PEEP).\n\nIn 23 patients (group 1) with acute respiratory distress syndrome (ARDS), PEEP was decreased from 10 to 5 cmH(2)O and, after 60′, it was increased Bcr-Abl inhibitor from 5 to 15 cmH(2)O. In 21 other ARDS patients (group 2), PEEP was increased from 10 to 15 cmH(2)O and, after 60′, decreased from 15 to 5 cmH(2)O. Oxygenation, ventilation, respiratory mechanics and hemodynamic variables were recorded at time 5′, 15′, 30′ and 60′ after each PEEP change.\n\nWhen PEEP was decreased, PaO2, PaO2/FiO(2), venous admixture and arterial oxygen saturation reached their equilibrium after 5′. In contrast, when PEEP was increased, the equilibrium was not reached even after 60′. The ventilation-related variables did not change significantly with PEEP. The respiratory system

compliance, when PEEP was decreased, significantly worsened only after 60′. Hemodynamics did not change significantly with PEEP. In the individual patients the change of oxygenation-related variables and of respiratory system compliance observed after 5′ could predict the changes recorded after 60′. This was not possible for PaCO2.\n\nWe could not find a unique equilibration Dihydrotestosterone solubility dmso time for all the considered variables. However, in general, a decremental PEEP test requires far lower equilibrium time than an incremental PEEP test, suggesting

a different time course for derecruitment and recruitment patterns.”
“OBJECTIVE: To determine the optimal first-line tocolytic agent for treatment of premature labor.\n\nMETHODS: We performed a quantitative analysis of randomized controlled trials of tocolysis, extracting data on maternal and neonatal outcomes, and pooling rates for each outcome across trials by treatment. Outcomes were delay of delivery for 48 hours, 7 days, and until 37 weeks; adverse effects causing discontinuation of therapy; absence of respiratory distress syndrome; and neonatal survival. We used weighted proportions from a random-effects meta-analysis in a decision model to determine the optimal first-line tocolytic therapy. Sensitivity analysis was performed using the standard errors of the weighted proportions.\n\nRESULTS: Fifty-eight studies satisfied the inclusion criteria.

The subunits cross at the GAF-B/catalytic domain linker, and each

The subunits cross at the GAF-B/catalytic domain linker, and each side of the dimer contains in series the GAF-A and GAF-B of one subunit and the catalytic domain of the other subunit. A dimer interface extends over the entire length of the molecule. The substrate binding pocket of each catalytic domain is occluded by the H-loop. We deduced from comparisons with structures of isolated, ligand-bound catalytic this website subunits that the H-loop swings out to allow substrate access. However, in dimeric PDE2A (215-900), the H-loops of the two catalytic subunits pack against each other at the dimer interface, necessitating movement of the catalytic subunits to allow for H-loop movement. Comparison

of the unliganded GAF-B of PDE2A (215-900) with previous structures of isolated, cGMP-bound GAF domains indicates that cGMP binding induces a significant shift in the GAF-B/catalytic domain

linker. We propose that cGMP binding to GAF-B causes movement, through this linker region, of the catalytic domains, such that the H-loops no longer pack at the dimer interface and are, instead, free to swing out to allow substrate access. This increase in substrate access is proposed as the basis for PDE2A activation by cGMP and may be a general mechanism for regulation of all PDEs.”
“Recurrent tumour after radical pancreaticoduodenectomy may cause obstruction of the small bowel loop draining the liver. Roux-loop obstruction presents a particular therapeutic challenge, since the postsurgical anatomy usually prevents endoscopic access. Careful multidisciplinary discussion

and multimodality Selleckchem Sapitinib preprocedure imaging are essential to accurately demonstrate the cause and anatomical location of the obstruction. Transhepatic or direct percutaneous stent placement should be possible in most eases, thereby avoiding long-term external biliary drainage. Gastropexy T-fasteners will secure the percutaneous access and reduce the risk of bile leakage. The static bile is invariably contaminated by gut bacteria, and systemic sepsis is to be expected. Enteral stents are preferable to biliary stents, and compound covered stents in a sandwich construction are likely to give the best long-term BB-94 price results. Transhepatic and direct percutaneous enteral stent insertion after jejunopexy is illustrated and the literature reviewed. (Gut Liver 2010; 4(Suppl. 1):S89-95)”
“Methods of evaluating population trends have recently received particular attention because of perceived declines in several species during the twentieth century. We have studied demographic traits of the peregrine falcon (Falco peregrinus) population in Bizkaia (Northern Spain) for 11 years. This species suffered a severe decline in the 1950s and 1960s and started to recover in the 1980s and 1990s, although the recovery trends differed between areas.

Finally,

Finally, FK228 molecular weight the co-localization in cardiomyocytes and interaction in vivo of MMP-2 and cMLCK

were observed. Purified recombinant rat cMLCK was concentration- and time-dependently degraded by rat MMP-2 in vitro, and this was prevented by the inhibition of MMP-2. These findings reveal that the I/R-activated MMP-2 leads to the degradation of cMLCK, resulting in a reduction of MLC-2v phosphorylation, and myofibrillar Ca2+-stimulated ATPase activity, which subsequently suppresses myocardial contractile function through a decrease of myofilament Ca2+ sensitivity. (C) 2014 Elsevier Ltd. All rights reserved.”
“This work describes a two-step conjugate synthesis of a porous organometallic nanostructured materials composed of ferrocenemonocarboxylic (Fc-COOH) and 3,4,9, 10-perylenetetracarboxylic dianhydride (PTCDA) and then a reagentless amperometric immunosensor prepared with positively

charged gold nanoparticles (PGN) immobilized in this nanostructure conductive film is developed. This nanostructured material containing ferrocenyl (PTC-Fc) could easily form stable film on the electrode surface with efficient redox-activity and excellent conductivity. Furthermore, with the negatively charged surface, this film can be used as an interface to adsorbing the PGN, which was prepared LDC000067 in organic solvents at relatively high concentrations with improved monodispersity compared to those prepared selleck screening library in aqueous solution. The presence of PGN provided a congenial microenvironment for adsorbed biomolecules and decreased the electron-transfer impedance. Thus, with carcinoembryonic antibody (anti-CEA) as a model antibody, the proposed immunosensor showed rapid and highly sensitive amperometric

response to carcinoembryonic antigen (CEA) with acceptable preparation reproducibility and stability. (c) 2007 Elsevier Ltd. All rights reserved.”
“Plant cysteine proteinase inhibitors (cystatins) play important roles in plant defense mechanisms. Some proteins that interact with cystatins may defend against abiotic stresses. Here, we showed that AtCaN2, a Ca2+-dependent nuclease in Arabidopsis, is transcribed in senescent leaves and stems and interacts with an Arabidopsis cystatin (AtCYSb) in a yeast two-hybrid screen. The interaction between AtCYSb and AtCaN2 was confirmed by in vitro pull-down assay and bimolecular fluorescence complementation. Agarose gel electrophoresis showed that the nuclease activity of AtCaN2 against kDNA was inhibited by AtCYSb, which suggests that AtCYSb regulates nucleic acid degradation in cells.

9 kg/m(2)) and randomly

assigned to one of two groups: mo

9 kg/m(2)) and randomly

assigned to one of two groups: motivational interviewing (MI) intervention (n = 28), or a self-directed intervention (SDI) (control) (n = 26). The MI intervention consisted of five consultations with health professionals (four with a Dietitian and one with an Exercise BV-6 Physiologist) who applied components of MI counselling to consultations with the women over a 12 month period. The SDI was developed as a control and these participants received print materials only. Outcome measures were collected at baseline, three, 12, 18 and 24 months and included weight (primary outcome), waist circumference, body composition, blood pressure, plasma markers of metabolic syndrome risk, dietary intake, physical activity and quality of life. Analysis of covariance will be used to investigate outcomes according

to intervention type and duration (comparing baseline, 12 and 24 months). Discussion: The 40-Something study is the first RCT aimed Wnt inhibitors clinical trials at preventing menopausal weight gain in Australian women. Importantly, this paper describes the methods used to evaluate whether a relatively low intensity, health professional led intervention will achieve better weight control in pre-menopausal women than a self-directed intervention. The results will add to the scant body of literature on obesity prevention methods at an under-researched high-risk life stage, and inform the development of population-based interventions. Trial registration: ACTRN12611000064909.”
“Andrographis paniculata (AP) is a traditional herbal medicine that is used for the treatment of inflammation-related disorders,

dyspepsia, and diarrhea. Recently, the biological effects of AP on cancer, microbial infections, cardiovascular disease, and inflammation were reported. However, neuroprotective actions of AP during glutamate-induced oxidative stress have not been investigated. In this study, we isolated andrographolide (AG) as an active compound from the ethanolic extract of AP leaves, and evaluated its neuroprotective mechanisms using glutamate-treated HT22 mouse hippocampal neuronal cells. Five mM glutamate LY333531 hydrochloride reduced cell survival significantly to 55.90 +/- 2.16%. However, 5 mu M AG restored cell viability to 102.19 +/- 13.98%. AG decreased the early apoptosis by inhibiting Ca2+ influx, intracellular reactive oxygen species production, and lipid peroxidation. Moreover, AG regulated the levels of Bcl-2, Bid, Bax, and apoptosis-inducing factor. AG also inhibited the phosphorylation of mitogen activated protein kinases including p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. (C) 2014 Elsevier Ltd. All rights reserved.”
“In the afterglow of an inductively coupled N-2 plasma, relative N atom densities are measured by ionization threshold mass spectrometry as a function of time in order to determine the wall loss time t(wN) from the exponential decay curves.