Desorption and ablation regimes in UV-MALDI: the critical fluence

Although MALDI is a widely used technique, there is so far no theoretical description able to reproduce some critical aspects of the experimental results. For example, there is experimental as well as theoretical controversy regarding the minimum laser fluence, i.e., the so-called fluence threshold (F _T), required to evaporate a sample. Furthermore, although the different processes involved in ion production have been the focus of many investigations, the fact is that the primary process for ion formation in MALDI is not desorption but ablation. In this work, we present a new phenomenological approach for understanding MALDI results based on a simple, but physically intuitive, idea consisting of limiting the laser-matter interaction process to three layers. This description allows us to consider the different processes that dominate ion formation, i.e., heat dissipation, as well as the different existing regimes. Concretely, we present the results for three different matrices, i.e., DHB, ferulic acid (FA) and α-cyano-4-hydroxycinnamic acid (CHCA), in the limit of low fluence. The simulations we carried out show great qualitative and pseudo-quantitative agreement with the experimental results. Also, based on the simulation results, it is possible to distinguish clearly between the two dominant regimes, i.e., desorption and ablation, and it is possible, therefore, to estimate the critical fluence (F _C) that defines the transition from one regime to another.

Hereditary angioedema: 24 years of experience in a Portuguese Reference Center

Summary

Hereditary angioedema (HAE) poses a high burden of disease, being its epidemiological and clinical data heterogeneous among countries, with no recent published studies concerning Portuguese patients. Therefore, we aimed to raise awareness of HAE and to contribute to clinical knowledge. An observational, descriptive, retrospective, and cross-sectional study was performed, that included a cohort of 126 patients followed in a single Portuguese Center. We observed a high prevalence of HAE-C1-INH type II (45.2% of patients). Most HAE patients (67.4%) presented the initial manifestations of the disease before adulthood, at a mean age of 12.6 ± 8.4 years. However, we found a long delay in HAE diagnosis, especially in those without family history (mean 20.7 ± 17.3 years). Stress was the most common trigger, followed by trauma and infection. Symptoms involving different systems were increasingly reported with increased disease duration. Cutaneous symptoms (95.0%) were more frequent, followed by gastrointestinal (80.7%), and respiratory symptoms (50.4%). HAE symptoms led to abdominal surgery in 22 (17.5%) patients and induced laryngeal edema requiring intubation/tracheostomy in 8 (6.3%) patients. Most patients were under long-term prophylaxis, mainly with attenuated androgens (62.7% of patients).The correct distinction between HAE and other common causes of angioedema is critical, allowing reduction of diagnostic delay, improvement of adequate management, and ultimately improving outcomes and quality of life of HAE patients.

Novel nonylphenol-degrading bacterial strains isolated from sewage sludge: Application in bioremediation of sludge

Nonylphenol (NP) is an anthropogenic pollutant frequently found in sewage sludge due to the insufficient degrading effectiveness of conventional WWTPs and has attracted attention as an endocrine disruptor. The aim of this study was to isolate specific NP-degrading bacteria from sewage sludge to be used in the degradation of this contaminant through bioaugmentation processes in aqueous solution and sewage sludge. Up to eight different bacterial strains were isolated, six of them not previously described as NP degraders. Bacillus safensis CN12 presented the best NP degradation in solution, and glucose used as an external carbon source increased its effect, reaching DT₅₀ degradation values (time to decline to half the initial concentration of the pollutant) of only 0.9 days and a complete degradation in <7 days. Four NP metabolites were identified throughout the biodegradation process, showing higher toxicity than the parent contaminant. In sewage sludge suspensions, the endogenous microbiota was capable of partially degrading NP, but a part remained adsorbed as bound residue. Bioaugmentation was used for the first time to remove NP from sewage sludge to obtain more environmentally friendly biosolids. However, B. safensis CN12 was not able to degrade NP due to its high adsorption on sludge, but the use of a cyclodextrin (HPBCD) as availability enhancer allowed us to extract NP and degrade it in solution. The addition of glucose as an external carbon source gave the best results since the metabolism of the sludge microbiota was activated, and HPBCD was able to remove NP from sewage sludge to the solution to be degraded by B. safensis CN12. These results indicate that B. safensis CN12 can be used to degrade NP in water and sewage sludge, but the method must be improved using consortia of B. safensis CN12 with other bacterial strains able to degrade the toxic metabolites produced.

Pediatric chest x-ray in covid-19 infection

BACKGROUND

The outbreak of COVID-19 has become pandemic. Pediatric population has been less studied than adult population and prompt diagnosis is challenging due to asymptomatic or mild episodes. Radiology is an important complement to clinical and epidemiological features.

OBJECTIVE

To establish the most common CXR patterns in children with COVID-19, evaluate interobserver correlation and to discuss the role of imaging techniques in the management of children.

MATERIALS AND METHODS

Forty-four patients between 0 and 16 years of age with confirmed SARS-Cov-2 infection and CXR were selected. Two paediatric radiologists independently evaluated the images and assessed the type of abnormality, distribution and evolution when available.

RESULTS

Median age was 79.8 months (ranging from 2 weeks to 16 years of age). Fever was the most common symptom (43.5 %). 90 % of CXR showed abnormalities. Peribronchial cuffing was the most common finding (86.3 %) followed by GGOs (50 %). In both cases central distribution was more common than peripheral. Consolidations accounted for 18.1 %. Normal CXR, pleural effusion, and altered cardiomediastinal contour were the least common.

CONCLUSION

The vast majority of CXR showed abnormalities in children with COVID-19. However, findings are nonspecific. Interobserver correlation was good in describing consolidations, normal x-rays and GGOs. Imaging techniques have a role in the management of children with known or suspected COVID-19, especially in those with moderate or severe symptoms or with underlying risk factors.

Thoracic outlet syndrome in adolescents: a case series

OBJECTIVE

Thoracic Outlet Syndrome (TOS) is caused by a compression of the brachial plexus and the subclavian vessels in their passage to the upper limb. It mostly occurs in women aged 20-50, so it is infrequent in children. We present our results in the diagnosis and management of pediatric TOS.

MATERIAL AND METHODS

Retrospective study of patients diagnosed with TOS between December 2017 and June 2018. Clinical, radiological, surgical, and evolution variables were assessed.

RESULTS

Five TOS were diagnosed in 4 patients - one TOS was bilateral. Mean age at diagnosis was 12.5 years (7-15), and there was a delay in diagnosis of 153 days (10-36). TOS was either venous (3) or neurogenic (2). Patients presented with pain (5/5), edema (4/5), hypoesthesia (3/5), decreased strength (3/5), and cervical pain (2/5). One patient presented with sport-related pain. Neurophysiological study was normal in three cases. Two patients presented bone anomalies at CT-scan. Three surgeries were performed in two patients using the supraclavicular approach with resection of the anomalous first rib and scalenectomy. One patient refused surgery, and another patient remained expectant without reappearance of symptoms. Postoperative follow-up was 9 months (6-12), with progressive improvement of symptoms.

CONCLUSIONS

TOS may occur in adolescents in the form of upper limb pain and edema. Imaging tests are recommended to detect abnormal anatomical structures. The supraclavicular approach represents a safe and effective technique in decompressing the thoracic outlet.

Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Haemodynamic profile of Spanish adults with Down syndrome

OBJECTIVES

Although the reasons are unknown, the prevalence of arterial hypertension and atherosclerotic cardiovascular events in the adult population with Down syndrome (SD) is anecdotal. To better understand this finding, we evaluated the haemodynamic characteristics of a cohort of adults with SD.

METHODS

We conducted a cross-sectional study of adults with SD recruited consecutively from the outpatient clinics of an internal medicine department between June and November 2018. We collected demographic, clinical and laboratory variables and employed a thoracic bioimpedance device (HOTMAN® System) for the haemodynamic measures. Outpatient blood pressure monitoring (OBPM) was conducted on a subgroup of participants.

RESULTS

Twenty-six participants (mean age, 45±11years) participated in the study (50% men). The sample's mean blood pressure (BP) was 109/69±11/9mmHg, with a mean heart rate of 60±12bpm. None of the participants had hypertension. The predominant haemodynamic profile consisted of normal dynamism (65%), normal BP (96%), hypochronotropism (46%), normal inotropism (50%) and hypervolaemia (54%), with normal peripheral vascular resistance values (58%). Twelve participants underwent OBPM (46%). The mean 24-h systolic BP, diastolic BP, mean BP and mean heart rate were 105±11mmHg, 67±11mmHg, 80±11mmHg and 61±6bpm, respectively.

CONCLUSIONS

The most common haemodynamic profile observed in adults with SD consisted of hypochronotropism and hypervolaemia, with normal values for peripheral vascular resistance and optimal mean BP values. There were no participants with hypertension in our sample.

Increase of germ cell nuclear factor expression in globozoospermic Gopc-/- knockout mice

BACKGROUND

Golgi-associated PDZ and coiled-coil motif-containing protein (GOPC) is a Golgi protein that plays a role in vesicular transport and intracellular protein trafficking and degradation. Mice deficient in GOPC protein have globozoospermia and are infertile. The germ cell nuclear factor (GCNF) is a member of the nuclear receptor superfamily which is expressed in male germ cells, from spermatocytes and spermatids, both in the nucleus and the acrosomal region. It is not known if its expression could be altered in Gopc^-/- mice with defective acrosomes.

OBJECTIVES

The aim of the present work was to analyze the distribution of GCNF protein in spermatids of Gopc^-/- knockout mice.

MATERIALS AND METHODS

We have analyzed the expression and distribution during spermatogenesis of GCNF and its deregulation in Gopc^-/- mutant mice by RT-qPCR, Western blot, immunohistochemistry and immunogold.

RESULTS

Germ cell nuclear factor was localized in the nucleus of all the cell types in the seminiferous tubules. Despite being a nuclear protein, it was also located in the acrosome and in the manchette of elongating spermatids. We have found that in the absence of GOPC, the expression of GCNF was increased in the nucleus of spermatocytes, mainly in leptotene, and in the nucleus and the manchette during the spermatid elongation.

DISCUSSION AND CONCLUSION

Gopc^-/- mice have defective acrosome and manchette. The manchette is involved in the transport of proteins through the cytoplasm and the nucleus. Considering that the GCNF protein is normally transported to the acrosome and the nucleus, it can be thought that transport deficiencies in Gopc^-/- mice are responsible for the increased expression of this protein.

Oral Immunotherapy for Food Allergy: A Spanish Guideline. Immunotherapy Egg and Milk Spanish Guide (ITEMS Guide). Part I: Cow Milk and Egg Oral Immunotherapy: Introduction, Methodology, Rationale, Current State, Indications, Contraindications, and Oral Immunotherapy Build-up Phase

BACKGROUND AND OBJECTIVE

Cow milk and egg are the most frequent causes of food allergy in the first years of life. Oral immunotherapy (OIT) has been investigated as an alternative to avoidance diets. No clinical practice guidelines on the management of OIT with milk and egg are currently available. Objectives: To develop clinical guidelines for OIT based on available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published between 1984 and June 2016, doctoral theses published in Spain, summaries of communications at scientific meetings (SEAIC, SEICAP, EAACI, and AAAAI), and the consensus of opinion established by a group of experts from the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations were established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of adverse reactions.

CONCLUSIONS

Clinical practice guidelines based on the consensus reached between Spanish experts are presented for the management of OIT with milk and egg.

Oral immunotherapy for food allergy: A Spanish guideline. Immunotherapy egg and milk Spanish guide (items guide). Part I: Cow milk and egg oral immunotherapy: Introduction, methodology, rationale, current state, indications contraindications and oral immunotherapy build-up phase

INTRODUCTION

Cow's milk and egg are the most frequent causes of food allergy in the first years of life. Treatments such as oral immunotherapy (OIT) have been investigated as an alternative to avoidance diets. No clinical practice guides on the management of OIT with milk and egg are currently available.

OBJECTIVES

To develop a clinical guide on OIT based on the available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published in the period between 1984 and June 2016, Doctoral Theses published in Spain, and summaries of communications at congresses (SEAIC, SEICAP, EAACI, AAAAI), with evaluation of the opinion consensus established by a group of experts pertaining to the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations have been established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of suffering adverse reactions.

CONCLUSIONS

A clinical practice guide is presented for the management of OIT with milk and egg, based on the opinion consensus of Spanish experts.

A multiscale approach to assess geomorphological processes in a semiarid badland area (Ebro Depression, Spain)

In this paper, three methods (Terrestrial Laser Scanner (TLS), terrestrial Structure from Motion photogrammetry (SfM) and aerial SfM photogrammetry with an Unmanned Aerial Vehicle (UAV)) were evaluated and compared to produce high resolution point clouds and Digital Elevation Models (DEMs) in a semiarid, complex badland area (Los Aguarales) with tourism activities. Geomorphological processes and dynamics were studied at different spatial scales. The preliminary results showed the possibilities of a multiscale approach, using various non-invasive techniques, to assess geomorphological processes. The high resolution of the point clouds, obtained with TLS and terrestrial SfM photogrammetry, allowed preliminary identification of numerous spatial details, although no relevant topographical changes were detected during a short, wet spring period (with rainfall of 200 mm). UAV images allowed work at larger scales (catchment), mapping piping features, and could be seen as a worthwhile tool for time-effective data acquisition from larger areas. The application of different technologies and a multiscale approach to generate high resolution DEMs is a useful technique when carrying out geomorphological studies in semiarid badland areas. However, long term studies will be necessary to verify the suitability of these techniques in such complex landscapes, and quantify topographical changes and erosion rates. Finally, the information obtained with these tools could be used to promote the study area as an interesting geomorphosite with opportunities for tourism.

Oral Immunotherapy for Food Allergy: A Spanish Guideline. Egg and Milk Immunotherapy Spanish Guide (ITEMS GUIDE). Part II: Maintenance Phase of Cow Milk (CM) and Egg Oral Immunotherapy (OIT), Special Treatment Dosing Schedules. Models of Dosing Schedules of OIT With CM and Egg

BACKGROUND AND OBJECTIVE

Cow milk and egg are the most frequent causes of food allergy in the first years of life. Oral immunotherapy (OIT) has been investigated as an alternative to avoidance diets. No clinical practice guidelines on the management of OIT with milk and egg are currently available. Objectives: To develop clinical guidelines for OIT based on available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published between 1984 and June 2016, doctoral theses published in Spain, summaries of communications at scientific meetings (SEAIC, SEICAP, EAACI, and AAAAI), and the consensus of opinion established by a group of experts from the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations were established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of adverse reactions.

CONCLUSIONS

Clinical practice guidelines based on the consensus reached between Spanish experts are presented for the management of OIT with milk and egg.

Biomonitoring of 21 endocrine disrupting chemicals in human hair samples using ultra-high performance liquid chromatography-tandem mass spectrometry

Rapid industrial growth has increased human exposure to a large variety of chemicals with adverse health effects. These industrial chemicals are usually present in the environment, foods, beverages, clothes and personal care products. Among these compounds, endocrine disrupting chemicals (EDCs) have raised concern over the last years. In the present work, the determination of 21 EDCs in human hair samples is proposed. An analytical method based on the digestion of the samples with a mixture of acetic acid/methanol (20:80, v/v) followed by a solid-liquid microextraction and analysis by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed and validated. The most influential parameters affecting the extraction method were optimized. The method was validated using matrix-matched calibration and recovery assays. Limits of detection ranged from 0.2 to 4 ng g^-1, limits of quantification from 0.5 to 12 ng g^-1, and inter- and intra-day variability was under 15% in all cases. Recovery rates for spiked samples ranged from 92.1 to 113.8%. The method was applied for the determination of the selected compounds in human hair. Samples were collected weekly from six randomly selected volunteers (three men and three women) over a three-month period. All the analyzed samples tested positive for at least one of the analyzed compounds.

Milk and blood biomarkers associated to the clinical efficacy of a probiotic for the treatment of infectious mastitis

Previous studies have shown the efficacy of oral administration of selected lactobacilli strains to treat mastitis. The objective of this study was to find microbiological, biochemical and/or immunological biomarkers of the probiotic effect. Women with (n=23) and without (n=8) symptoms of mastitis received three daily doses (10(9) cfu) of Lactobacillus salivarius PS2 for 21 days. Samples of milk, blood and urine were collected before and after the probiotic intervention, and screened for a wide spectrum of microbiological, biochemical and immunological parameters. In the mastitis group, L. salivarius PS2 intake led to a reduction in milk bacterial counts, milk and blood leukocyte counts and interleukin (IL)-8 level in milk, an increase in those of immunoglobulin (Ig)E, IgG3, epidermal growth factor and IL-7, a modification of the milk electrolyte profile, and a reduction of some oxidative stress biomarkers. Such biomarkers will be useful in future clinical studies involving a larger cohort.

Non-linear photoelectron effect contributes to the formation of negative matrix ions in UV-MALDI

The mechanism of negative ion formation in matrix-assisted laser desorption/ionization (MALDI) is less well understood than that of positive ions: electron capture, disproportionation, and liberation of negatively charged sample molecules or clusters have been proposed to produce the initial anions in MALDI.

Validated method for the determination of perfluorinated compounds in placental tissue samples based on a simple extraction procedure followed by ultra-high performance liquid chromatography-tandem mass spectrometry analysis

Xenobiotic exposure during pregnancy is inevitable. Determination of perfluorinated compounds (PFCs), chemicals described as environmental contaminants by Public Health Authorities due to their persistence, bioaccumulation and toxicity, is a challenge. In the present work, a method based on a simplified sample treatment involving freeze-drying, solvent extraction and dispersive clean-up of the extracts using C18 sorbents followed by an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis was developed and validated for the determination of five perfluorinated carboxylic acids (C4-C8) and perfluorooctane sulfonate (PFOS) in placental tissue samples. The most influential parameters affecting the extraction method and clean-up were optimized using Design of Experiments (DOE). The method was validated using matrix-matched calibration. Found limits of detection (LODs) ranged from 0.03 to 2 ng g(-1) and limits of quantification (LOQs) from 0.08 to 6 ng g(-1), while inter- and intra-day variability was under 14% in all cases. Recovery rates for spiked samples ranged from 94% to 113%. The method was satisfactorily applied for the determination of compounds in human placental tissue samples collected at delivery from 25 randomly selected women.

Targeted diagnostic magnetic nanoparticles for medical imaging of pancreatic cancer

Highly aggressive cancer types such as pancreatic cancer possess a mortality rate of up to 80% within the first 6months after diagnosis. To reduce this high mortality rate, more sensitive diagnostic tools allowing an early stage medical imaging of even very small tumours are needed. For this purpose, magnetic, biodegradable nanoparticles prepared using recombinant human serum albumin (rHSA) and incorporated iron oxide (maghemite, γ-Fe2O3) nanoparticles were developed. Galectin-1 has been chosen as target receptor as this protein is upregulated in pancreatic cancer and its precursor lesions but not in healthy pancreatic tissue nor in pancreatitis. Tissue plasminogen activator derived peptides (t-PA-ligands), that have a high affinity to galectin-1 have been chosen as target moieties and were covalently attached onto the nanoparticle surface. Improved targeting and imaging properties were shown in mice using single photon emission computed tomography-computer tomography (SPECT-CT), a handheld gamma camera, and magnetic resonance imaging (MRI).

New insights into the causes of human illness due to consumption of azaspiracid contaminated shellfish

Azaspiracid (AZA) poisoning was unknown until 1995 when shellfish harvested in Ireland caused illness manifesting by vomiting and diarrhoea. Further in vivo/vitro studies showed neurotoxicity linked with AZA exposure. However, the biological target of the toxin which will help explain such potent neurological activity is still unknown. A region of Irish coastline was selected and shellfish were sampled and tested for AZA using mass spectrometry. An outbreak was identified in 2010 and samples collected before and after the contamination episode were compared for their metabolite profile using high resolution mass spectrometry. Twenty eight ions were identified at higher concentration in the contaminated samples. Stringent bioinformatic analysis revealed putative identifications for seven compounds including, glutarylcarnitine, a glutaric acid metabolite. Glutaric acid, the parent compound linked with human neurological manifestations was subjected to toxicological investigations but was found to have no specific effect on the sodium channel (as was the case with AZA). However in combination, glutaric acid (1mM) and azaspiracid (50nM) inhibited the activity of the sodium channel by over 50%. Glutaric acid was subsequently detected in all shellfish employed in the study. For the first time a viable mechanism for how AZA manifests itself as a toxin is presented.

Bromoalkaloids protect primary cortical neurons from induced oxidative stress

Bromoalkaloids are secondary metabolites with a demonstrated high activity in several therapeutic areas. In this research, we probe the neuroprotective and antioxidant activities of hymenialdisine and hymenin. Both structures were tested in an oxidative stress cellular model, consisting of cortical neurons that are incubated with the oxidative stress inducer hydrogen peroxide and the tested compound. Several oxidation biomarkers were analyzed, and the results of the oxidative stress induced neurons in the presence and absence of bromoalkaloids were compared. Both compounds demonstrated significant neuroprotective ability under stress conditions at low nanomolar concentrations, with hymenialdisine highlighted for demonstrating a more complete protection. Also, the activity of hymenialdisine and hymenin was studied in the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway, and, for the first time, these halogenated metabolites are described as Nrf2 inducers, reinforcing the antioxidant capacity observed and therefore opening a new path of investigation. These results, added to the previously described effect of this compound family in negatively modulating several kinases and proinflammatory cytokines, position hymenialdisine and hymenin as good candidates for the development of new drugs for neurodegenerative diseases.

Trace organics removal using three membrane bioreactor configurations: MBR, IFAS-MBR and MBMBR

Seventeen pharmaceutically active compounds and 22 other trace organic pollutants were analysed regularly in the influent and permeate from a semi-real plant treating municipal wastewater. The plant was operated during 29 months with different configurations which basically differed in the type of biomass present in the system. These processes were the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR), which combined suspended and attached biomass, the moving bed membrane bioreactor (MBMBR) (only attached biomass) and the MBR (only suspended biomass). Moreover, removal rates were compared to those of the wastewater treatment plant (WWTP) operating nearby with conventional activated sludge treatment. Reverse osmosis (RO) was used after the pilot plant to improve removal rates. The highest elimination was found for the IFAS-MBR, especially for hormones (100% removal); this was attributed to the presence of biofilm, which may lead to different conditions (aerobic-anoxic-anaerobic) along its profile, which increases the degradation possibilities, and also to a higher sludge age of the biofilm, which allows complete acclimation to the contaminants. Operating conditions played an important role, high mixed liquor suspended solids (MLSS) and sludge retention time (SRT) being necessary to achieve these high removal rates. Although pharmaceuticals and linear alkylbenzene sulfonates showed high removal rates (65-100%), nonylphenols and phthalate could only be removed to 10-30%. RO significantly increased removal rates to 88% mean removal rate.

A reliable method for rhythm analysis during cardiopulmonary resuscitation

Interruptions in cardiopulmonary resuscitation (CPR) compromise defibrillation success. However, CPR must be interrupted to analyze the rhythm because although current methods for rhythm analysis during CPR have high sensitivity for shockable rhythms, the specificity for nonshockable rhythms is still too low. This paper introduces a new approach to rhythm analysis during CPR that combines two strategies: a state-of-the-art CPR artifact suppression filter and a shock advice algorithm (SAA) designed to optimally classify the filtered signal. Emphasis is on designing an algorithm with high specificity. The SAA includes a detector for low electrical activity rhythms to increase the specificity, and a shock/no-shock decision algorithm based on a support vector machine classifier using slope and frequency features. For this study, 1185 shockable and 6482 nonshockable 9-s segments corrupted by CPR artifacts were obtained from 247 patients suffering out-of-hospital cardiac arrest. The segments were split into a training and a test set. For the test set, the sensitivity and specificity for rhythm analysis during CPR were 91.0% and 96.6%, respectively. This new approach shows an important increase in specificity without compromising the sensitivity when compared to previous studies.

Automatic detection of chest compressions for the assessment of CPR-quality parameters

AIM

Accurate chest compression detection is key to evaluate cardiopulmonary resuscitation (CPR) quality. Two automatic compression detectors were developed, for the compression depth (CD), and for the thoracic impedance (TI). The objective was to evaluate their accuracy for compression detection and for CPR quality assessment.

METHODS

Compressions were manually annotated using the force and ECG in 38 out-of-hospital resuscitation episodes, comprising 869 min and 67,402 compressions. Compressions were detected using a negative peak detector for the CD. For the TI, an adaptive peak detector based on the amplitude and duration of TI fluctuations was used. Chest compression rate (CC-rate) and chest compression fraction (CCF) were calculated for the episodes and for every minute within each episode. CC-rate for rescuer feedback was calculated every 8 consecutive compressions.

RESULTS

The sensitivity and positive predictive value were 98.4% and 99.8% using CD, and 94.2% and 97.4% using TI. The mean CCF and CC-rate obtained from both detectors showed no significant differences with those obtained from the annotations (P>0.6). The Bland-Altman analysis showed acceptable 95% limits of agreement between the annotations and the detectors for the per-minute CCF, per-minute CC-rate, and CC-rate for feedback. For the detector based on TI, only 3.7% of CC-rate feedbacks had an error larger than 5%.

CONCLUSION

Automatic compression detectors based on the CD and TI signals are very accurate. In most cases, episode review could safely rely on these detectors without resorting to manual review. Automatic feedback on rate can be accurately done using the impedance channel.