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High flow nasal oxygen (HFNO) is proven to be effective in non-COVID-19 hypoxemic respiratory failure. In the beginning of the COVID-19 pandemic, HFNO was quickly introduced into daily clinical practice, although the evidence of its effectiveness in COVID-19 was limited. Randomized controlled trials suggest that HFNO has no effect on survival. However, HFNO may lead to less intubations in comparison with conventional oxygen therapy. The evidence of HFNO use in patients with do-not-intubate orders remains very limited. However, in these patients, improvement in comfort could be an important argument to start treatment with HFNO. Additional research is needed to make an evidence based consideration about the clinical use of HFNO in COVID-19 care.

Prescription of long term oxygen treatment ( LTOT),based on old studies, is only indicated if there is severe hypoxaemia at rest (PaO28,0 kPa) and should be used atleast 15 hours per day.However as newer treatments like nocturnal non-invasive ventilatory support showed to be beneficial, LTOT stands not on its own but should be part of a multidimensional approach in individual patients with COPD.

Pulse oximetry detects hypoxemia non-invasively by measuring light absorption at different wave lengths, depending on the oxygenation of hemoglobin. The plethysmographic signal is caused by volume changes in the arterial blood during systole. In this pulsatile flow, oxygen saturation is calculated using an algorithm. Use of the pulse oximeter has increased massively, especially in the COVID-era, and has a central role in managing patients at the emergency department. However, interpretation of the plethysmogram is frequently incorrect which may lead to incorrect conclusions. Moreover, an irregular plethysmographic signal may well 'give' a saturation percentage. We will discuss how pulse oximeters work and discuss some pitfalls. We hope that understanding the mechanism behind pulse oximetry, as well as an awareness of pitfalls, leads to improved management of patients with consequently less unnecessary care, as demonstrated in our case.

Prescription of long term oxygen treatment ( LTOT),based on old studies, is only indicated if there is severe hypoxaemia at rest (PaO2 < 8,0 kPa) and should be used atleast 15 hours per day.However as newer treatments like nocturnal non-invasive ventilatory support showed to be beneficial, LTOT stands not on its own but should be part of a multidimensional approach in individual patients with COPD.

Prescription of long term oxygen treatment ( LTOT),based on old studies, is only indicated if there is severe hypoxaemia at rest (PaO2 < 8,0 kPa) and should be used atleast 15 hours per day.However as newer treatments like nocturnal non-invasive ventilatory support showed to be beneficial, LTOT stands not on its own but should be part of a multidimensional approach in individual patients with COPD.

We present two patients who were treated for an intentional overdose of sodium nitrite. When ingested sodium nitrite leads to severe methaemoglobinaemia, resulting in severe hypoxia (as methaemoglobin does not transport oxygen), vasodilation and hypotension. Symptoms include cyanosis, headache, nausea, convulsions, coma and death. When measured by pulse oximetry, patients with a sodium nitrite intoxication and severe methaemoglobinaemia generally have an oxygen saturation of around 85%. This value is unreliable as the oxygen content of the blood is often extremely low - this can be confirmed by arterial blood gas analysis. Treatment of sodium nitrite intoxication consists of intravenous administration of methylthioninium chloride 1-2 mg/kg. Methylthioninium chloride converts the methaemoglobin back to haemoglobin. Due to the pharmacokinetics of methylthioninium chloride and sodium nitrite, a rebound effect is not to be expected. The only contra-indication for methylthioninium chloride is glucose-6-phosphate dehydrogenase deficiency, which is extremely rare in the Netherlands.

Nasal cannulae for oxygen administration are applied abundantly in clinical medicine, even though their use may cause patient discomfort. Although nasal cannulae may be effective in increasing oxygen uptake to some degree, they are unlikely to prevent severe hypoxaemia. Furthermore, they are often used when arterial oxygen saturation is already ≥ 90%, in which case additional oxygenation is usually not required, nor does it relieve the sensation of dyspnoea.

Long-term oxygen therapy in patients with pronounced hypoxia is an important and life-extending therapy. Many patients have only mild hypoxia, do not experience nocturnal desaturation, or experience desaturation only during exercise. While often applied in clinical practice, the clinical relevance of oxygen therapy was not clear in these patients. A recent randomized controlled trial has now revealed no additional value for long-term oxygen therapy in subjects with mild oxygen desaturation or exercise-induced oxygen desaturation only. Furthermore, treatment burden, adverse events and healthcare costs associated with oxygen therapy need to be considered; restriction of the prescription of oxygen therapy is, therefore, appropriate. On the other hand, oxygen therapy is still considered important in non-severe hypoxic subjects with severe exercise-related desaturation (80%); in selected cases during endurance training in pulmonary rehabilitation; or in individual subjects with desaturation and pronounced and proven benefit of oxygen therapy on their symptoms and exercise capacity.

High nasal flow (HNF) is a new method to deliver a high flow of oxygen (up to 60 l/min) through a nasal cannula. The inspiratory oxygen fraction can be set in a range from 21 to 100%. The inspired air is adjusted to body temperature and saturation. Many patients find it more comfortable than a conventional oxygen mask. In spite of these advantages, the mechanism of action is not completely understood and empirical evidence for its use is limited. This article provides a simplified explanation of variable positive airway pressure generation by HNF and related flushing of the anatomic dead space. Based on a short discussion of recent studies, it is concluded that HNF is a promising technique but that questions remain about the indications for use in clinical practice.

In de zomers van 2003 en 2006 kwam in de Maas massale sterfte voor van de Aziatische korfmossel Corbicula fluminea. Op basis van beschikbare gegevens van de waterkwaliteit in de Maas in 2006 lijkt de oorzaak te liggen in een combinatie van ongunstige factoren, zoals een hoge watertemperatuur in combinatie met lage zuurstofgehalten en/of een laag voedselaanbod, die het sterkst lokaal tot uiting komen tijdens een (zomer)periode met lage waterafvoer. Duidelijk werd dat de standaardgegevens van de vaste meetstations onvoldoende informatie leveren om de oorzaak van de lokale mosselsterfte met zekerheid vast te stellen. Hiervoor is het noodzakelijk om zo snel mogelijk na een melding van sterfte op locatie metingen te verrichten. Rijkswaterstaat Limburg heeft hiertoe inmiddels praktische en organisatorische maatregelen genomen

Cancer cells are characterised by altered metabolism compared to healthy tissue. Ninety years ago, the German medical doctor and biochemist Otto Warburg discovered that tumours--when compared to healthy tissue--convert considerably more glucose into lactate, regardless of oxygen presence. This phenomenon is known as the Warburg effect; it is a hallmark of most cancer types and can be well understood by the process of somatic evolution. The Warburg effect explains the significance of the PET scan and may offer opportunities for new treatments of cancer.

Human lysine-specific demethylase (LSD1) is a chromatin-modifying enzyme that specifically removes methyl groups from mono- and dimethylated Lys4 of histone H3 (H3-K4). We used a combination of in vivo and in vitro experiments to characterize the substrate specificity and recognition by LSD1. Biochemical assays on histone peptides show that essentially all epigenetic modifications on the 21 N-terminal amino acids of histone H3 cause a significant reduction in enzymatic activity. Replacement of Lys4 with Arg greatly enhances binding affinity, and a histone peptide incorporating this mutation has a strong inhibitory power. Conversely, a peptide bearing a trimethylated Lys4 is only a weak inhibitor of the enzyme. Rapid kinetics measurements evidence that the enzyme is efficiently reoxidized by molecular oxygen with a second-order rate constant of 9.6x10(3) M-1 s-1, and that the presence of the reaction product does not greatly influence the rate of flavin reoxidation. In vivo experiments provide a correlation between the in vitro inhibitory properties of the tested peptides and their ability of affecting endogenous LSD1 activity. Our results show that epigenetic modifications on histone H3 need to be removed before Lys4 demethylation can efficiently occur. The complex formed by LSD1 with histone deacetylases 1/2 may function as a "double-blade razor" that first eliminates the acetyl groups from acetylated Lys residues and then removes the methyl group from Lys4. We suggest that after H3-K4 demethylation, LSD1 recruits the forthcoming chromatin remodelers leading to the introduction of gene repression marks.

International audience; The NADPH-dependent dimeric flavoenzyme 4-hydroxyacetophenone monooxygenase (HAPMO) catalyzes Baeyer-Villiger oxidations of a wide range of ketones, thereby generating esters or lactones. In the current work, we probed HAPMO-coenzyme complexes present during the enzyme catalytic cycle with the aim to gain mechanistic insight. Moreover, we investigated the structural role of the nicotinamide coenzyme. For these studies, we used (i) wild type HAPMO, (ii) the R339A variant, which is active but has a low affinity toward NADPH, and (iii) the R440A variant, which is inactive but has a high affinity toward NADPH. Electrospray ionization mass spectrometry was used as the primary tool to directly observe noncovalent protein-coenzyme complexes in real time. These analyzes showed for the first time that the nicotinamide coenzyme remains bound to HAPMO during the entire catalytic cycle of the NADPH oxidase reaction. This may also have implications for other homologous Baeyer-Villiger monooxygenases. Together with the observations that NADP(+) only weakly interacts with oxidized enzyme and that HAPMO is mainly in the reduced form during catalysis, we concluded that NADP(+) interacts tightly with the reduced form of HAPMO. We also demonstrated that the association with the coenzyme is crucial for enzyme stability. The interaction with the coenzyme analog 3-aminopyridine adenine dinucleotide phosphate (AADP(+)) strongly enhanced the thermal stability of wild type HAPMO. This coenzyme-induced stabilization may also be important for related enzymes.

Objective: To study whether lower arterial oxygen saturation (SaO2) and chronic obstructive pulmonary disease (COPD) are associated with cerebral white matter lesions and lacunar infarcts. Methods: We measured SaO2 twice with a pulse oximeter, assessed the presence of COPD, and performed MRI in 1077 non-demented people from a general population (aged 60–90 years). We rated periventricular white matter lesions (on a scale of 0–9) and approximated a total subcortical white matter lesion volume (range 0–29.5 ml). All analyses were adjusted for age and sex and additionally for hypertension, diabetes, body mass index, pack years smoked, cholesterol, haemoglobin, myocardial infarction, and left ventricular hypertrophy. Results: Lower SaO2 was independent of potential confounders associated with more severe periventricular white matter lesions (score increased by 0.12 per 1% decrease in SaO2 (95% confidence interval 0.01 to 0.23)). Participants with COPD had more severe periventricular white matter lesions than those without (adjusted mean difference in score 0.70 (95% confidence interval 0.23 to 1.16)). Lower SaO2 and COPD were not associated with subcortical white matter lesions or lacunar infarcts. Conclusion: Lower SaO2 and COPD are associated with more severe periventricular white matter lesions.

Vanwege het plan om de wateruitwisseling tussen het Grevelingenmeer en de Noordzee te vergroten met als doel de waterkwaliteit in het Grevelingenmeer te verbeteren, is er een onderbouwing nodig voor de zuurstofconcentratie die niet onderschreden zou moeten worden voor het bodemleven in het Grevelingenmeer. Op basis van een literatuurstudie is een inschatting gemaakt van grenswaarden voor het zuurstofgehalte voor verschillende soortgroepen zeedieren.

Vanwege het plan om de wateruitwisseling tussen het Grevelingenmeer en de Noordzee te vergroten met als doel de waterkwaliteit in het Grevelingenmeer te verbeteren, is er een onderbouwing nodig voor de zuurstofconcentratie die niet onderschreden zou moeten worden voor het bodemleven in het Grevelingenmeer. Op basis van een literatuurstudie is een inschatting gemaakt van grenswaarden voor het zuurstofgehalte voor verschillende soortgroepen zeedieren.

Zaden zijn het beste houdbaar als je ze koel en droog bewaart. Maar het kan nog veel beter: zuurstofloos. Dat toont onderzoek van Steven Groot (PRI) en collega’s aan.

Zaden zijn het beste houdbaar als je ze koel en droog bewaart. Maar het kan nog veel beter: zuurstofloos. Dat toont onderzoek van Steven Groot (PRI) en collega’s aan.

Elk bewaarseizoen kent zijn bijzonderheden, zo ook seizoen 2004-2005. Dit werd gekenmerkt dooe schilvlekjes die al vroeg in het seizoen ontstonden, maar ook de goede tot zeer goede uitstalkwaliteit van Elstar. Bij Conference kwamen slappe nekken dankzij de extra aandacht voor dit probleem nauwelijks voor. Dit terwijl juist bij Elstar meer dan normaal werd gereclameerd over een 'slappere' appel. In dit artikel een terugblik en adviezen voor het nieuwe bewaarseizoen

Smoking from a water pipe has become increasingly popular, but this is not as innocent as it seems.Three women presented to the emergency department after having smoked from a water pipe. The first patient had experienced a syncopal episode and still had symptoms of dizziness and a headache afterwards. The second patient only had a headache and the third had no symptoms. The physical examinations and standard vital sign measurements of all three patients were normal. Analyses of the arterial blood gases, however, showed carbon monoxide (CO) poisoning: the patients had HbCO concentrations of 22, 19.5 and 5.7%, respectively. We administered high concentrations of oxygen to each, but the first 2 patients continued to experience symptoms for several weeks. The CO poisoning was probably caused by the incomplete combustion of the charcoal in the water pipe which resulted in CO being released.The regular or even one-time use of a water pipe containing tobacco or an aromatised substance can cause CO poisoning. Patients can continue to experience symptoms for weeks after an episode of acute CO poisoning.

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Bilateral diaphragm paralysis is a serious condition causing failure to sleep in the supine position and this condition often results into severe hypercapnia leading to respiratory failure. Here we describe two cases that required mechanical ventilation, and subsequently failed to respond to intermittent non-invasive ventilation. Subjects were successfully taken from mechanical ventilation after unilateral plication of a hemidiafragm and one of them further improved after plication of the contralateral paralysed diaphragm. Remarkably, decompression of the left lower lung lobe after 20 years of lobar atelectasis resulted in rapid improvement of ventilation and gas exchange.

In this paper, the effect of root oxygen loss on energy recovery of the plant microbial fuel cell (PMFC) is described. In this manner, advanced understanding of competing processes within the rhizosphere-anode interface was provided. A microscopic model was developed on the basis of exudation, oxygen loss, biological oxidation, and biological current generation. The model was successfully validated by comparison to oxygen concentration profiles, volatile fatty acid profiles, and chemical oxygen demand profiles measured in the anode compartment. The model predicted oxic zones around roots in the anode of the plant microbial fuel cell. Results show no direct link between current generation and photosynthesis. This was consistent with the model which predicted that current was generated via hydrolysis of root-derived organic compounds. This result means that to optimize energy recovery of a PMFC, the plant selection should focus on high root biomass production combined with low oxygen loss.

DCS-bewaring is uitgegroeid tot een toepasbaar laag zuurstofbewaarsysteem. Met dit systeem van Food & Biobased Research behoudt de bewaarder niet alleen kwaliteit in de lange bewaring, maar blijft de hardheid vooral in de uitstalperiode op peil. Specifiek voor Elstar is voordeel te behalen in de vorm van minder schilvlekjes.

The use of medicinal oxygen can be dangerous. The spontaneous combustion of an oxygen cylinder was the cause of a fire in an operating theatre and an emergency medical service. The fire developed after turning on the gas main while the flow supply valve was already open. Not opening the pressure reduction valve while the oxygen flow supply valve is open can prevent this type of fire. Information from the contractor shows that the probability of such an incident is 1 in a million.

To study the incidence of hypoxaemia and bradycardia in children who undergo guillotine adenotonsillectomy in a sitting position, without intubation and under inhalation anaesthesia.Retrospective study.Analysis of age, weight, sex, oxygen saturation, heart rate and subsequent bleeding in all children up to the age of 11 years who underwent guillotine adenotonsillectomy in the period December 1999 to December 2007. Hypoxaemia was defined as oxygen saturation of less than 85% for longer than 60 s. Bradycardia was defined as a heart rate of less than 60/min for longer than 30 s.We analysed data from 2963 patients. The mean age was 4.7 years and mean weight 18.8 kg. There was no significant relationship between age, weight and the onset of incidental desaturation or bradycardia. A total of 132 patients (4.5%) had hypoxaemia and 280 patients (9.4%) had bradycardia. Twenty-five patients had both hypoxaemia and bradycardia, of whom 3 (0.1%) had bradycardia immediately following hypoxaemia. In none of the recorded episodes of hypoxaemia and bradycardia did this lead to peri- or postoperative complications.Hypoxaemia and bradycardia occurred during guillotine adenotonsillectomy in non-intubated children in a sitting position under inhalation anaesthesia. The simultaneous onset of hypoxaemia and bradycardia is rare, however, and does not lead to perioperative complications. A further study is required using adenotonsillectomy with a large number of intubated and non-intubated children in order to compare the incidence of hypoxaemia and bradycardia and the occurrence of complications.

Chronic lung damage (bronchopulmonary dysplasia (BPD)) is one of the most serious complications affecting preterm neonates. During the last decade the aetiology of BPD has changed. Whereas 'classic BPD' was characterised mainly by lung damage and fibrosis caused by oxygen toxicity and mechanical ventilation, 'new BPD' is characterised by a disorder in lung development. This aetiological shift has been brought about by improved survival in extremely premature infants as a result of, for instance, antenatal corticosteroid administration and postnatal surfactant therapy. New BPD requires a new therapeutic approach. Therapeutic options for developing BPD include caffeine, vitamin A and postnatal corticosteroids. Once BPD has occurred, diuretics and inhaled bronchodilators and corticosteroids may be useful. However, the available therapies decrease the risk of developing BPD by just a small percent. In the future, artificial surfactants and non-invasive ventilation may prove to be useful in the prevention of BPD.

De voorbereidingen voor het bewaarseizoen 2010 zijn in volle gang. De ULO-cellen worden getest en indien nodig gasdicht gemaakt. Controle op veiligheid van de cellen is een standaardprocedure geworden tijdens de voorbereidingen op de oogst. Instructies en stappenplan voor monstername.

Under the influence of air, a facile 1,4-addition of diethylzinc to acyloxypyranones and alkoxypyranones 1 takes place. Reaction of diethylzinc with molecular oxygen provides EtOOZnEt, which cataly...

Biologische grondontsmetting (BGO) is een niet-chemisch manier om grond te ontsmetten. Het principe berust op de vertering van grote hoeveelheden vers organisch materiaal onder zuurstofloze omstandigheden, ook wel fermentatie genoemd. Op dit moment gebeurt dat met gras dat in de zomer in de grond wordt verwerkt

Sleutelfactoren en ecosysteemfunctioneren. Dit rapport beschrijft onderzoek dat gedaan is naar mogelijke sleutelfactoren voor aquatisch ecologische kwaliteit in laagveensloten. Het onderzoek is uitgevoerd in vier deelgebieden in de Wieden, die in een gradiënt van sterke beïnvloeding (eutrofiëring) naar een meer natuurlijke situatie lagen. Gedurende het jaar zijn vier meerdaagse zuurstofmetingen per sloot uitgevoerd. Hieruit bleek dat de zuurstofconcentraties vooral aan de bodem erg laag konden worden, ongeacht de mate van eutrofiëring. Oorzaak hiervan was temperatuurstratificatie, die in de meeste sloten gedurende het grootste deel van het jaar zeer frequent optrad. Vervolgonderzoek naar de precieze invloed van deze stratificatie op de macrofauna in de sloot wordt aanbevolen

Bewaren van appels met DCS (Dynamic Control System) is dé methode om de kwaliteit van vooral Elstar te waarborgen. DCS-appels zijn met vertrouwen in de markt gezet en kunnen dan ook gezien worden als het topsegment van fruit

The objective of this pilot study was to investigate whether addition of O2 to the CO2 gas mixture improves pig welfare during slaughter. In a pilot experiment 3 different CO2/O2 mixtures were compared with the standard CO2 concentration Voor het verdoven van slachtvarkens worden in principe 2 methoden in de huidige praktijk toegepast: elektrische bedwelming en CO2 verdoving. Op basis van literatuuronderzoek, het onderzoek naar verdoofd castreren van biggen en inventarisatie van de technische mogelijkheden heeft dit onderzoek zich niet meer gericht op een 2-fasen-systeem, maar op het welzijnseffect van het toevoegen van O2 aan hoge CO2-concentraties voor het verdoven van varkens vòòr de slacht, waardoor er uitzicht komt op een mogelijke verbetering van de huidige CO2-verdovingsmethode. In een pilotexperiment zijn 3 verschillende CO2/O2 mengsels vergeleken met de huidige in de praktijk toegepaste CO2-concentratie

Twee biotelers hebben hun grond ontsmet door organisch materiaal in de vorm van gras onder te werken en vervolgens de bodem luchtdicht af te dekken met plastic gedurende zes weken. Wageningen UR Glastuinbouw volgt het proces. Uit de eerste analyseresultaten lijkt Verticillium niet of niet voldoende afgedood. Mogelijk is er wel een verzwakking, waardoor de ontsmetting toch effectief is. De aaltjes lijken op het ene bedrijf wel en op het andere bedrijf nauwelijks te worden gedood

Dit rapport beschrijft onderzoek naar mogelijke sleutelfactoren voor aquatisch ecologische kwaliteit in laagveensloten. Laagveensloten vertonen in de zomer zeer lage zuurstofconcentraties aan de bodem door het optreden van temperatuurstratificatie. Uit experimenten bleek dat lage zuurstofconcentraties aan de bodem ervoor kunnen zorgen dat dieren naar zuurstofrijkere waterlagen migreren waar ze beter kunnen overleven. Kortdurende zuurstofarme periodes kunnen ook onderin de waterkolom overbrugd worden. Als zuurstofconcentraties als gevolg van een slechte waterkwaliteit langdurig over de hele waterkolom laag zijn, verschuift de macrofaunagemeenschap naar een gemeenschap met meer poly- en alfa-mesosprobe soorten

Sleutelfactoren en ecosysteemfunctioneren. Dit rapport beschrijft onderzoek dat gedaan is naar mogelijke sleutelfactoren voor aquatisch ecologische kwaliteit in laagveensloten. Het onderzoek is uitgevoerd in vier deelgebieden in de Wieden, die in een gradiënt van sterke beïnvloeding (eutrofiëring) naar een meer natuurlijke situatie lagen. Gedurende het jaar zijn vier meerdaagse zuurstofmetingen per sloot uitgevoerd. Hieruit bleek dat de zuurstofconcentraties vooral aan de bodem erg laag konden worden, ongeacht de mate van eutrofiëring. Oorzaak hiervan was temperatuurstratificatie, die in de meeste sloten gedurende het grootste deel van het jaar zeer frequent optrad. Vervolgonderzoek naar de precieze invloed van deze stratificatie op de macrofauna in de sloot wordt aanbevolen

The objective of this pilot study was to investigate whether addition of O2 to the CO2 gas mixture improves pig welfare during slaughter. In a pilot experiment 3 different CO2/O2 mixtures were compared with the standard CO2 concentration

Twee biotelers hebben hun grond ontsmet door organisch materiaal in de vorm van gras onder te werken en vervolgens de bodem luchtdicht af te dekken met plastic gedurende zes weken. Wageningen UR Glastuinbouw volgt het proces. Uit de eerste analyseresultaten lijkt Verticillium niet of niet voldoende afgedood. Mogelijk is er wel een verzwakking, waardoor de ontsmetting toch effectief is. De aaltjes lijken op het ene bedrijf wel en op het andere bedrijf nauwelijks te worden gedood

Dit rapport beschrijft onderzoek naar mogelijke sleutelfactoren voor aquatisch ecologische kwaliteit in laagveensloten. Laagveensloten vertonen in de zomer zeer lage zuurstofconcentraties aan de bodem door het optreden van temperatuurstratificatie. Uit experimenten bleek dat lage zuurstofconcentraties aan de bodem ervoor kunnen zorgen dat dieren naar zuurstofrijkere waterlagen migreren waar ze beter kunnen overleven. Kortdurende zuurstofarme periodes kunnen ook onderin de waterkolom overbrugd worden. Als zuurstofconcentraties als gevolg van een slechte waterkwaliteit langdurig over de hele waterkolom laag zijn, verschuift de macrofaunagemeenschap naar een gemeenschap met meer poly- en alfa-mesosprobe soorten