Filter Failure Research Articles

A Study of Personal Information Management Strategies for Online Faculty

The literature suggests that personal information management is a serious challenge for many computer users. Online faculty are especially challenged because of the large number of electronic files necessitated by teaching online. Those who have experience in this environment may offer valuable insights regarding information management challenges and practices. Faculty who teach online courses as part of the WISE (Web-based Information Science Education) Consortium responded to a survey that questioned the ways they manage email, computer desktop, Web-based information and learning management systems. The authors concluded that “filter failure” rather than information overload is the key issue in information management. The study concludes with a list of recommendations for faculty to manage their personal information.

Effect of paclitaxel on proliferation of human Tenon fibroblast and its probably mechanism

Background The excessive growth of human Tenon fibroblasts (HTFs) is a primary cause of failure of anti-glaucomatous filtering surgery.To seek a drug of anti-fibrosis is of an important significance for improving the successful rate of anti-glaucomatous filtration surgery.Objective The goal of this study was to investigate the effect of paclitaxel on proliferation of HTFs in vitro.Methods Human Tenon tissue was obtained during the anti-glaucomatous filtering surgery.HTFs were cultivated using explant method and 3-6 generations of cells were used in the experiment.The cells were identified by immunochemistry using keratin,vimentin,fibronectin and S-100.Different concentrations (0,1 ×10-s,1 × 10-7,1 × 10-6 mol/L) of paclitaxel were added into the medium,and then the cell indexes (CI) in the various groups were detected by real-time cell electronic sensing (RT-CES) 24 hours after affection of paclitaxel.Apoptosis of the cells was examined using DAPI staining,and the proportion of the cells in different cycles were assayed by flow cytorneter 12 hours after addition of paclitaxel.The expressions of matrix metalloproteinase-1 (MMP-1) protein and mRNA were detected by ELISA and real-time PCR,respectively.Results The cells migrated from the cultivated tissue within 7 days with the fibrocyte-like shape.The cells showed the positive response for vimentin and absent response for keratin,fibronectin and S-100.The CI values were 1.093 ±0.191,0.665 ± 0.093 and 0.473 ± 0.117 in the 1 × 10-8,1 × 10-7 and 1 × 10-6 mol/L paclitaxel groups,showing significant rise in comparison with the 1.514 ±0.283 of the 0 mol/L paclitaxel group (all at P =0.000).The cell nuclei were normal in the 0 mol/L paclitaxel group,however,blue-fluorescent particles and apoptotic bodied were found in the cell nuclei after affection of paclitaxel.The proportion of G2/M phase of cells were (9.20±0.80) ％,(12.37±0.45)％ and (13.80±0.35)％ in the 1×10-8 mol/L,1×10-7 mol/L and 1×10-6 mol/L paclitaxel groups,which were higher than the (7.17±0.50) ％ in the 0 mol/L paclitaxel group (P=0.005,0.000,0.000).In addition,the relative expressing level of M MP-1 mRNA (MMP-1 mRNA/GAPDH mRNA) and the expression level of MMP-1 protein in the HTFs were significantly lower in the 1 ×10-8 mol/L,1 × 10-7 mol/L and 1 × 10-6 mol/L paclitaxel groups than those in the 0 mol/L group (all at P＜0.05).Conclusions Paclitaxel at the concentrations of 1 × 10-8 mol/L-1 × 10-6 mol/L inhibits the proliferation of HTFs in vitro by arresting the cellular mitosis and inducing cell apoptosis.These effects probably associated with down-regulation of MMP-1 expression in the HTFs. Key words: Paclitaxe/pharmacology ; Glaucoma/surgery; Tenon capsule/ cytology; Fibroblast/cytology; Matrix metalloproteinase-1

Influence of Laser Beam Diameter on the Resistance of Laser Protection Filters to Laser Radiation

Abstract Beside the total laser power, the laser beam diameter is a significant factor for the resistance of laser protection filters to laser radiation. In this paper a study of the resistance of laser protection filters to laser radiation in dependence of the laser beam diameter is given. For the investigation of this effect an experimental setup is realized, which detects laser radiation near the MPE value (ref.1) (Maximum Permissible Exposure; level of laser radiation to which, under normal circumstances, persons may be exposed without suffering adverse effects) behind the filter glasses, which is taken as a criteria for the failure of laser protection filters. This failure defines the laser resistance time of the protection filter under the given laser parameters (laser power and laser beam diameter). The experiments involve a series of irradiations from a cw (continuous wave) Nd:YAG laser (wavelength 1064 nm) with the variation of laser power, laser beam diameter and with different material thicknesses. The dependency of the laser resistance time follows a power function of the laser beam diameter. It is shown that by performing only a few dedicated laser resistance tests for a specific type of laser protection filter, it is possible to calculate the laser resistance time for different laser beam diameters occurring in practical lab situations.

Determination of the Soot Mass by Conductometric Soot Sensors

Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. If installed upstream of a DPF, the “engine-out” soot emissions can be determined by conductometric soot sensors. For that purpose, conductometric soot sensors were characterized in a diesel engine under varying operation conditions. Sensor data and soot analytics (SMPS) agree well. However, the orientation of the sensor electrodes with respect to the exhaust flow direction significantly affects the sensor signal.

Silencing The Brain May Be Better Than Stimulating it. The GABA Effect

Cases of recovery from vegetative and minimally conscious state after the administration of various pharmacological agents have been recently reported. These agents include CNS depressants (zolpidem, baclofen, lamotrigine) and CNS stimulants (tricyclic antidepressants, selective serotonin reuptake inhibitors, dopaminergic agents, methylphenidate). The action of CNS depressants as awakening agents sounds paradoxical, as they are commonly prescribed to slow down brain activity in the management of anxiety, muscle tension, pain, insomnia and seizures. How these drugs may improve the level of consciousness in some brain-injured patients is the subject of intense debate. Here we hypothesize that CNS depressants may promote consciousness recovery by reversing a condition of GABA impairment in the injured brain, restoring the normal ratio between synaptic excitation and inhibition, which is the prerequisite for any transition from a resting state to goal-oriented activities (GABA impairment hypothesis). Alternative or complementary mechanisms underlying the improvement of consciousness may include the reversal of a neurodormant state within areas affected by diaschisis (diaschisis hypothesis) and the modulation of an informative overload to the cortex as a consequence of filter failure in the injured brain (informative overload hypothesis). A better understanding of how single agents act on neural networks, whose functioning is critical for recovery, may help to advance a tailored pharmacological approach in the treatment of severely brain injured patients.

Op Ed-If Filter Failure is the Problem, Then What Is Filter Success?

Op Ed-If Filter Failure is the Problem, Then What Is Filter Success?

Journal bibliometrics indicators and citation ethics: A discussion of current issues

Science has recently been accelerating at a fast rate, resulting in what has been called “information overload” and more recently “filter failure”. In this perspective, journal performance indicators can play an important role in journal evaluation. Opinions on the appropriate use of journal-level bibliometrics indicators can be divided but they have now long been used as measures in research evaluation, and many editors see it as part of their editorial duty to try and improve bibliometrics indicators and rankings for their journal. There are various techniques through which this can be attempted, some more ethical than others. Some editors may try to boost the bibliometrics performance of their journals through gratuitous citations. This is problematic because citations are meant to provide useful references, scientifically justifiable, to previously published literature. As such citations can be used as widely accepted measures of scientific impact. Therefore, superfluous citations can distort the validity of bibliometrics indicators. It might be tempting to try to improve a journal's bibliometrics rankings at all costs, but these are only as meaningful as the data that feed into them. Exceedingly inflated indicators due to unethical behaviours can damage the reputation of a journal and its editors, and can lead to a loss of quality manuscript submissions, which in turn is likely to affect the journal's future citation impact.

First Level Prevention Instead of Third Level Intervention—Review of Research to Improve Biocompatibility and Performance of Capillary Membrane Apheresis in Critically Ill Patients

In intensive care medicine, convection-based apheresis is of growing interest. Applying extracorporeal systems in the critically ill patient can cause severe complications like nosocomial infections and bleeding, which can be worsened or even initialized by the anticoagulation protocol used. Furthermore, the filter modules (hemo- and plasmafilters) often tend to a fast blockage. A decrease in sieving performance due to membrane fouling may be tolerable for some time, but the complete blockage of high percentages of hollow fibers, which is named "clotting," often requires the immediate exchange of the filter. Extracorporeal detoxification and high clearance renal replacement regimes both require high blood flow and filtration rates. As a consequence, filter clotting and anticoagulation-associated bleeding are the most sensitive aspects in these applications. We were interested in the paradox phenomenon of the parallel occurrence of intra vitam bleeding and filter clotting in critically ill patients. Through stepwise investigations based on in vitro and animal experiments, we identified a stasis of blood flow followed by blood cell sedimentation and aggregation ("clogging") as the main factor of hollow fiber blockage in hemo- and plasma filters. As a result, various aspects which increase the risk of stasis inside the hollow fibers were investigated, for example, patient's hemorheology, configuration of an extracorporeal treatment system including interaction of catheter features with the filtration procedure, and basic therapeutic approaches such as colloidal volume substitutes and tolerated acidosis. Finally, an etiological triad for the blockage of hollow fibers due to filter clogging and consecutive filter failure was formed.

Lifecycle Testing Results of Dimple Pleat Radial Flow HEPA Filters Under Ambient and Elevated Conditions

The Institute for Clean Energy Technology (ICET) at Mississippi State University (MSU) has developed testing capabilities for evaluating the American Society of Mechanical Engineers (ASME) Code on Nuclear Air and Gas Treatment (AG-1) section FK radial flow HEPA filters. These high efficiency particulate air (HEPA) filters are typically used at sites within the DOE complex to control particulate matter emissions. The goal of this testing was to provide information related to the performance of radial flow HEPA filters that use dimple pleat separators. Prior to this testing, insufficient data were available to determine the lifecycle performance of these filters. Two different types of dimple pleated radial flow HEPA filters were tested: a safe change design and a remote change design. Filters were tested at both ambient and elevated conditions of temperature and relative humidity. The challenge aerosols were Alumina (Al(OH)3), Carbon black, and Arizona road dust. The performance of these filters at ambient conditions was determined by the filters’ mass loading capacity and filtering efficiency. Elevated condition performance was evaluated by the filters’ resistance to elevated temperature and relative humidity. The results indicated that the challenge aerosol had a large impact on the total loading capacity of the filters. Testing at elevated conditions of temperature and relative humidity revealed an issue with the strength of the dimple pleats. The dimples softened when challenged with elevated conditions, which led to filter failure due to a cascading reduction in free flow area and increase in differential pressure.Copyright 2013 American Association for Aerosol Research

Dynamic pressure measurements of a hot gas filter as a diagnostic tool to assess the time dependent performance

Dynamic pressure measurements are introduced as powerful tool to detect filter failures at early stage. Data of single recleaning pulses or a time series of recleaning pulses can be used to detect filter failures and changes in filter candle conditions during commissioning and operation. High frequency sensors were used to record recleaning back pressure pulses enabling the detection of filter failures such as leakages or blockages. Changes in filter wall resistance due to patchy cleaning or depth filtration can be detected much faster with dynamic pressure measurements than with conventional differential pressure measurements. Parameters derived from dynamic pressure data were monitored over time and compared with reference data. The method complements standard pressure difference measurements. Dynamic pressure measurements were conducted at a hot gas filter applying a coupled pressure pulse (CPP) recleaning system.

Inhibitory effect of apigenin on human Tenon capsule fibroblasts

Background Proliferation of the human Tenon capsule fibroblasts(HTFs) is a main cause of failure of filtering surgery.To search the drug of inhibiting the growth of the HTFs is essential for the improvement of successful rate of filtering surgery.Objective The aim of this study was to investigate the inhibitory effect of apigenin on HTFs and its mechanism.Methods Human Tenon capsular tissue was obtained during the strabismus correction surgery.HTFs was primarily cultured using explant method and identified using vimentin by immunochemistry.The 3-5 generation of cells were incubated to 96-well plate.Apigenin of 0,20,40,80,160 μmol/L was added into the medium,respectively,for 24,48,72 hours,and the proliferation of HTFs was detected by sulfonyl chloride (SRB) at the wavelength of 560 nm (A560).Bromodeoxyuridine (BrdU) of 10 μg/L was added to culture the cells for 48 hours to calculate the labeling rate of BrdU.The morphology of the cells was observed using Hoechst 33258 staining,and apoptosis and cells cycle were evaluated by flow cytometry.Results Cultured cells grew well with the positive response for vimentin,showing the green fluorescence in cytoplasm.SRB assay showed that the A560 value was gradually declined with the increase of the dosage of apigenin and prolong of time (Fgroup =480.306,P =0.000 ; Ftime =555.144,P =0.000).The labeling rate after 0,40,80 μmol/L apigenin acted for 48 hours was (87.860 ±0.632)％,(61.520±4.306)％ and (23.480±4.472)％,showing a significant difference among the three groups (F =299.347,P =0.000).The labeling rate of HTFs for BrdU was significantly decreased in the 40 and 80 μmol/L apigenin groups compared with the 0 μmol/L apigenin group (P＜0.05).Hoechse 33258 staining found that the number of the HTFs was gradually decreased and the cell number of karyopyknosis and nuclear deformation was increased with the increase of apigenin dosage.Percentage of cells in G0/G1 phase were raised and that in S and G2/M phase were declined in the higher dosage apigenin group,with a significant difference among the different groups (FG0/G1 =58.621,P=0.000;Fs =32.357,P=0.001 ;FG2/M =83.998,P=0.000).In the 72nd hour after acted by 0,40,80,160 μmol/L apigenin,the apoptosis rate of HTFs was (4.77±0.21) ％,(13.24±1.35)％,(18.33±1.86) ％,(31.58 ± 2.77) ％,respectively,with a statistically significant difference among the four groups (F =204.791,P＜0.05).Conclusions Apigenin restrains the growth of HTFs by evoking G0/G1 cell cycle arrest and inducing apoptosis in a dosage-and time-dependent manner. Key words: Apigenin; Human Tenon capsule fibroblast; Apoptosis

Impact of Different Types of Resuscitation Fluids on Coagulation and Continuous Venovenous Hemofiltration Hemocompatibility in a Porcine Model

Intensive therapy demanding diseases (organ failure or sepsis) are assumed to be the etiology behind a decreased biocompatibility of extracorporeal systems for renal replacement therapy (RRT). There are also potential interactions between different components of the overall therapy. Volume substitutes are known to influence hemorheology and coagulation. To define a potential net effect of volume substitutes on the hemocompatibility of an RRT, we chose an animal model without interfering pathophysiologies. According to the problem of early filter failure and coagulation disorders in critically ill patients, we focused on the hypothesized interaction between RRT and different volume substitutes with respect to blood cell counts, coagulation parameters and required heparin dose. Forty-eight pigs were assigned to four groups of fluid therapy with either normal saline (NaCl), 6%HES130kD/0.4 (HES130), 6%HES200kD/0.5 (HES200) or 4%gelatin (GEL). Six pigs of each fluid group underwent continuous venovenous hemofiltration (CVVH), the remaining six served as the control group. Anticoagulation was performed with continuous heparin infusion. CVVH was run in a recirculation-mode for 4.5 h to force hemocompatibility reactions, thereafter in a standard-mode for 2 h. During the CVVH-treatment GEL reduced platelet counts and fibrinogen concentration and additionally lowered ATIII levels. Heparin requirements did not differ between different volume substitutes or CVVH and control groups. Severe pathophysiologies are not the only reason for a reduced hemocompatibility of CVVH treatment. Interaction of a particular volume substitute with CVVH should be considered when interpreting study results and evolving new strategies.

Ensemble clustering in deterministic ensemble Kalman filters

ABSTRACTEnsemble clustering (EC) can arise in data assimilation with ensemble square root filters (EnSRFs) using non-linear models: an M-member ensemble splits into a single outlier and a cluster of M–1 members. The stochastic Ensemble Kalman Filter does not present this problem. Modifications to the EnSRFs by a periodic resampling of the ensemble through random rotations have been proposed to address it. We introduce a metric to quantify the presence of EC and present evidence to dispel the notion that EC leads to filter failure. Starting from a univariate model, we show that EC is not a permanent but transient phenomenon; it occurs intermittently in non-linear models. We perform a series of data assimilation experiments using a standard EnSRF and a modified EnSRF by a resampling though random rotations. The modified EnSRF thus alleviates issues associated with EC at the cost of traceability of individual ensemble trajectories and cannot use some of algorithms that enhance performance of standard EnSRF. In the non-linear regimes of low-dimensional models, the analysis root mean square error of the standard EnSRF slowly grows with ensemble size if the size is larger than the dimension of the model state. However, we do not observe this problem in a more complex model that uses an ensemble size much smaller than the dimension of the model state, along with inflation and localisation. Overall, we find that transient EC does not handicap the performance of the standard EnSRF.

Hemofiltration compared to hemodialysis for acute kidney injury: systematic review and meta-analysis

IntroductionThe objective of this systematic review and meta-analysis was to determine the effect of renal replacement therapy (RRT), delivered as hemofiltration vs. hemodialysis, on clinical outcomes in patients with acute kidney injury (AKI).MethodsMEDLINE, EMBASE and CENTRAL databases and conference abstracts were searched to June 2012 for parallel-group or crossover randomized and quasi-randomized controlled trials (RCTs) evaluating hemofiltration vs. hemodialysis in patients with AKI. Two authors independently selected studies and abstracted data on study quality and outcomes. Additional information was obtained from trial authors. We pooled data using random-effects models.ResultsOf 6,657 citations, 19 RCTs (10 parallel-group and 9 crossover) met inclusion criteria. Sixteen trials used continuous RRT. Study quality was variable. The primary analysis included three parallel-group trials comparing similar doses of hemofiltration and hemodialysis; sensitivity analyses included trials comparing combined hemofiltration-hemodialysis or dissimilar doses. We found no effect of hemofiltration on mortality (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.73 to 1.25, P = 0.76; three trials, n = 121 (primary analysis); RR 1.10, 95% CI 0.88 to 1.38, P = 0.38; eight trials, n = 540 (sensitivity analysis)) or other clinical outcomes (RRT dependence in survivors, vasopressor use, organ dysfunction) compared to hemodialysis. Hemofiltration appeared to shorten time to filter failure (mean difference (MD) -7 hours, 95% CI (-19,+5), P = 0.24; two trials, n = 50 (primary analysis); MD -5 hours, 95% CI (-10, -1), P = 0.01; three trials, n = 113 (including combined hemofiltration-hemodialysis trials comparing similar doses); MD -6 hours, 95% CI (-10, -1), P = 0.02; five trials, n = 383 (sensitivity analysis)). Data primarily from crossover RCTs suggested that hemofiltration increased clearance of medium to larger molecules, including inflammatory cytokines, compared to hemodialysis, although almost no studies measured changes in serum concentrations. Meta-analyses were based on very limited data.ConclusionsData from small RCTs do not suggest beneficial clinical outcomes from hemofiltration, but confidence intervals were wide. Hemofiltration may increase clearance of medium to larger molecules. Larger trials are required to evaluate effects on clinical outcomes.

Performance evaluation of immunity-based statistical en-route filtering in wireless sensor networks

Statistical en-route filtering (SEF) schemes can detect and eliminate false data injection attacks in wireless sensor networks. However, SEF does not address the identification of the compromised nodes which are injecting false reports. Therefore, we have proposed an immunity-based SEF to identify compromised nodes and achieve earlier detection of false reports. In the proposed scheme, each node has a list of neighborhood nodes and assigns credibility to each neighboring node. Each node can update the credibility of a neighboring node based on the success or failure of filtering and communication, and can then use the updated credibility as the probability of the next communication. In this article, some simulation results show that the immunity-based SEF outperforms the original SEF.

Nafamostat Mesilate as an Anticoagulant during Continuous Veno-Venous Hemodialysis: A Three-Year Retrospective Cohort Study

Although nafamostat mesilate, a synthetic serine protease inhibitor, has been commonly used in Japan as an anticoagulant during continuous renal replacement therapy (CRRT), its clinical utility has not been well determined. The aim of this study was to evaluate the efficacy (filter survival) and safety (bleeding complications) of nafamostat mesilate in CRRT for acute kidney injury (AKI) among critically ill patients. We retrospectively studied consecutive patients with AKI treated with continuous veno-venous hemodialysis and nafamostat mesilate from April 2005 to March 2008. Demographic, clinical and laboratory data were extracted from the clinical chart. Fifty-eight patients were enrolled in this study (45 males with an average age of 66±15 years). The median filter survival was 21.8 h (range: 2.8-55.5 h), and the mean was 20.8±8.4 h. Only 38 out of 181 filters (21%) were interrupted because of filter failure within 24 hours and 89 filters (49%) were electively renewed within 24 hours. Activated partial thromboplastin time was elevated especially during the first 24 hours (46.7±13.1 s at baseline versus 73.9±24.3 s at day 1; ANOVA p<0.01). Hematocrit level was kept around 30% and did not change significantly (ANOVA p=0.69). No patients experienced major bleeding while treated with CRRT. Nafamostat mesilate provided sufficient filter survival without causing major bleeding complications despite the prolongation of APTT.

Design and performance evaluation of dry cleaning process for syngas

Coal gasification is one of the most promising options for clean, efficient and continuous power generation, though little progress has been made towards its commercialisation. One of the main hurdles of the commercialisation is reliability of the syngas cleaning process involving separation of critical impurities which can adversely affect the downstream process, and may result in plant shutdown. For example, failure of particulate capturing operation could have instant effect on downstream turbine, catalytic membrane, fuel cell and CO2 separation, therefore hot filtration is considered as the most critical process step in the gas cleaning process. Failure of sulphur, chlorine, alkali and trace element capture steps may also cause serious damage to the downstream processes but the effect will be noticeable after a relatively longer period of operation. During this period it could be possible to take some corrective actions, either manually or through an automatic control system, to prevent the damage. An automatic control system for particulate system could also be suggested to prevent the damage during filter failure but this would also demand installation of an additional backup filtration unit to continue the operation while failed unit is bypassed for repair. Considering these factors, the reliability of gas cleaning process at reasonable costs appears to be the biggest challenge for the commercialisation of the gasification technologies. A laboratory scale dry gas cleaning unit has been developed and tested at CSIRO to address some of these challenges. This paper illustrates some of the performance results obtained from the tests prior to detailed scale-up studies to be undertaken.

It's not filter failure, it's a discovery deficit

The web has changed our information-seeking behaviour radically, yet scholarly communication remains firmly embedded in the traditions of the print world. Here, I argue that the dropping costs of publication and distribution mean that effort and resource expended on preventing publication is wasted and that developing the tools and culture for post- publication annotation, curation and ranking is more productive. Rather than see this as information overload, or in Clay Shirky’s words, a ‘filter failure’, I propose that it is more useful to see the problem as a ‘discovery deficit’.This flood of content, instead of being a problem, is an opportunity to build technical and cultural frameworks that will enable us to extract more value from the outputs of research by exploiting the efficiencies that web-based systems can provide.

Do Reorganization Costs Matter for Efficiency? Evidence from a Bankruptcy Reform in Colombia

An efficient bankruptcy system should liquidate nonviable businesses and reorganize viable ones. The importance of this filtering process has long been recognized in the literature; the typical reason advanced for its failure has been biases (in codes or among judges). In this paper we show that bankruptcy costs can be another source of such filtering failure. We illustrate this with the Colombian reform of 1999. Using data from 1,924 firms filing for bankruptcy between 1996 and 2003, we find that the prereform reorganization proceedings were so inefficient that the bankruptcy system failed to separate economically viable firms from inefficient ones. In contrast, by streamlining the reorganization process, the reform contributed to the improvement of the selection of viable firms into reorganization. In this sense, the new law increased the efficiency of the bankruptcy system in Colombia.

Influence of acidaemia and hypoxaemia on CVVH haemocompatibility in a porcine model

Reduced haemocompatibility and early filter failure during continuous venovenous haemofiltration (CVVH) can be attributed to various aspects from filter engineering to rheological problems. Still, little is known about the impact of acidaemia and hypoxaemia on the haemocompatibility of a CVVH. In a porcine model, we investigated blood and coagulation parameters, filter performance and blockage of filter capillaries to assess the impact of acidaemia and hypoxaemia on haemocompatibility. Pigs were assigned to three groups (n = 6). One group received mixed acidaemia (pH 7.2) by acid infusion (0.2 M of lactic acid and 0.2 M HCl diluted in normal saline) and low tidal volume ventilation (6-8 mL/kg(-)(1)), one group underwent an additional hypoxaemia (pH 7.2; PaO(2) < 70 mmHg) and another was treated with normal saline and normoventilation (control group; pH 7.4). To accelerate biocompatibility reactions, CVVH was operated with reinfusion of the filtrate to the venous line for 3 h based on standardized heparinization. Acidaemia led to a contradictory pattern with respect to prothrombin time (prolongation), activated partial thrombin time and activated clotting time (acceleration). In comparison to normal pH homeostasis, acidaemia led to increasing activation markers such as terminal complement complex marker sC5b-9, thrombin-anti-thrombin complexes (TAT) and D-dimers. Additional hypoxaemia intensified activation with regard to TAT and complement complex marker sC5b-9. Platelet counts suffered from acidaemia and a tendency for higher rates of blocked hollow fibres was found. Acidaemia led to deteriorated haemocompatibility reactions to a CVVH circuit. The coagulation pattern developed towards complications for the coagulatory state.