Technical Note: mzML and imzML Libraries for Processing Mass Spectrometry Data with the High-Performance Programming Language Julia.

Julia combines the virtues of high-level and low-level programming languages: The code is human-readable, and the performance of the created binaries competes with machine-orientated compilers. Thus, Julia is popular in "Big Data" sciences. Reading mass spectrometry (MS) data with Julia was impossible until now due to missing libraries. Here, we present a Julia library for importing mass spectrometry (MS) data in HUPO standard mzML and imzML formats and demonstrate its function with direct and ambient ionization MS, liquid chromatography-MS, and MS imaging data on standard platforms (Windows, Linux, and Mac OS). The processing speed of Julia for reading imzML MS imaging files was up to 214 times faster than the comparable code in R. Julia can remove bottlenecks for computationally demanding tasks in large-scale MS-Omics and MS imaging data processing workflows and supports their agile development. In addition, time-critical and complex data evaluation tasks become possible, such as following the real-time monitoring of biological processes and pattern recognition in large MS imaging projects. Our mzML/imzML libraries and code examples are available under the terms of the MIT license from https://github.com/CINVESTAV-LABI/julia_mzML_imzML.

Guided analysis of ambient ionization mass spectrometry data with the MQ_Assistant.

RATIONALE: Ambient ionization mass spectrometry (AIMS) delivers realistic data from samples in their native state. In addition, AIMS methods reduce time and costs for sample preparation and have less environmental impact. However, AIMS data are often complex and require substantial processing before interpretation. METHODS: We developed an interactive R script for guided mass spectrometry (MS) data processing. The "MQ_Assistant" is based on MALDIquant, a popular R package for MS data processing. In each step, the user can try and preview the effect of chosen parameters before deciding on the values with the best result and proceeding to the next stage. The outcome of the MQ_Assistant is a feature matrix that can be further analyzed in R and statistics tools such as MetaboAnalyst. RESULTS: Using 360 AIMS example spectra, we demonstrate the step-by-step processing for creating a feature matrix. In addition, we show how to visualize the results of three biological replicates of a plant-microbe interaction between Arabidopsis and Trichoderma as a heatmap using R and upload them to MetaboAnalyst. The final parameter set can be saved for reuse in MALDIquant workflows of similar data. CONCLUSIONS: The MQ_Assistant helps novices and experienced users to develop workflows for (AI)MS data processing. The interactive procedure supports the quick finding of appropriate settings. These parameters can be exported and reused in future projects. The stepwise operation with visual feedback also suggests the use of the MQ_Assistant in education.

A continuous in silico learning strategy to identify safety liabilities in compounds used in the leather and textile industry.

There is a widely recognized need to reduce human activity's impact on the environment. Many industries of the leather and textile sector (LTI), being aware of producing a significant amount of residues (Keßler et al. 2021; Liu et al. 2021), are adopting measures to reduce the impact of their processes on the environment, starting with a more comprehensive characterization of the chemical risk associated with the substances commonly used in LTI. The present work contributes to these efforts by compiling and toxicologically annotating the substances used in LTI, supporting a continuous learning strategy for characterizing their chemical safety. This strategy combines data collection from public sources, experimental methods and in silico predictions for characterizing four different endpoints: CMR, ED, PBT, and vPvB. We present the results of a prospective validation exercise in which we confirm that in silico methods can produce reasonably good hazard estimations and fill knowledge gaps in the LTI chemical space. The proposed protocol can speed the process and optimize the use of resources including the lives of experimental animals, contributing to identifying potentially harmful substances and their possible replacement by safer alternatives, thus reducing the environmental footprint and impact on human health.

Hyperkalemia in acute heart failure: Short term outcomes from the EAHFE registry.

OBJECTIVE: Both hyperkalemia (HK) and Acute Heart Failure (AHF) are associated with increased short-term mortality, and the management of either may exacerbate the other. As the relationship between HK and AHF is poorly described, our purpose was to determine the relationship between HK and short-term outcomes in Emergency Department (ED) AHF. METHODS: The EAHFE Registry enrolls all ED AHF patients from 45 Spanish ED and records in-hospital and post-discharge outcomes. Our primary outcome was all-cause in-hospital death, with secondary outcomes of prolonged hospitalization (>7 days) and 7-day post-discharge adverse events (ED revisit, hospitalization, or death). Associations between serum potassium (sK) and outcomes were explored using logistic regression by restricted cubic spline (RCS) curves, with sK =4.0 mEq/L as the reference, adjusting by age, sex, comorbidities, patient baseline status and chronic treatments. Interaction analyses were performed for the primary outcome. RESULTS: Of 13,606 ED AHF patients, the median (IQR) age was 83 (76-88) years, 54% were women, and the median (IQR) sK was 4.5 mEq/L (4.3-4.9) with a range of 4.0-9.9 mEq/L. In-hospital mortality was 7.7%, with prolonged hospitalization in 35.9%, and a 7-day post-discharge adverse event rate of 8.7%. Adjusted in-hospital mortality increased steadily from sK ≥4.8 (OR = 1.35, 95% CI = 1.01-1.80) to sK = 9.9 (8.41, 3.60-19.6). Non-diabetics with elevated sK had higher odds of death, while chronic treatment with mineralocorticoid-receptor antagonists exhibited a mixed effect. Neither prolonged hospitalization nor post-discharge adverse events was associated with sK. CONCLUSION: In ED AHF, initial sK >4.8 mEq/L was independently associated with in-hospital mortality, suggesting that this cohort may benefit from aggressive HK treatment.

Socio-Demographic Health Determinants Are Associated with Poor Prognosis in Spanish Patients Hospitalized with COVID-19.

INTRODUCTION: Social vulnerability is a known determinant of health in respiratory diseases. Our aim was to identify whether there are socio-demographic factors among COVID-19 patients hospitalized in Spain and their potential impact on health outcomes during the hospitalization. METHODS: A multicentric retrospective case series study based on administrative databases that included all COVID-19 cases admitted in 19 Spanish hospitals from 1 March to 15 April 2020. Socio-demographic data were collected. Outcomes were critical care admission and in-hospital mortality. RESULTS: We included 10,110 COVID-19 patients admitted to 18 Spanish hospitals (median age 68 (IQR 54-80) years old; 44.5% female; 14.8% were not born in Spain). Among these, 779 (7.7%) cases were admitted to critical care units and 1678 (16.6%) patients died during the hospitalization. Age, male gender, being immigrant, and low hospital saturation were independently associated with being admitted to an intensive care unit. Age, male gender, being immigrant, percentile of average per capita income, and hospital experience were independently associated with in-hospital mortality. CONCLUSIONS: Social determinants such as residence in low-income areas and being born in Latin American countries were associated with increased odds of being admitted to an intensive care unit and of in-hospital mortality. There was considerable variation in outcomes between different Spanish centers.

Elucidating the Distribution of Plant Metabolites from Native Tissues with Laser Desorption Low-Temperature Plasma Mass Spectrometry Imaging.

Secondary metabolites of plants have important biological functions, which often depend on their localization in tissues. Ideally, a fresh untreated material should be directly analyzed to obtain a realistic view of the true sample chemistry. Therefore, there is a large interest for ambient mass-spectrometry-based imaging (MSI) methods. Our aim was to simplify this technology and to find an optimal combination of desorption/ionization principles for a fast ambient MSI of macroscopic plant samples. We coupled a 405 nm continuous wave (CW) ultraviolet (UV) diode laser to a three-dimensionally (3D) printed low-temperature plasma (LTP) probe. By moving the sample with a RepRap-based sampling stage, we could perform imaging of samples up to 16 × 16 cm2. We demonstrate the system performance by mapping mescaline in a San Pedro cactus ( Echinopsis pachanoi) cross section, tropane alkaloids in jimsonweed ( Datura stramonium) fruits and seeds, and nicotine in tobacco ( Nicotiana tabacum) seedlings. In all cases, the anatomical regions of enriched compound concentrations were correctly depicted. The modular design of the laser desorption (LD)-LTP MSI platform, which is mainly assembled from commercial and 3D-printed components, facilitates its adoption by other research groups. The use of the CW-UV laser for desorption enables fast imaging measurements. A complete tobacco seedling with an image size of 9.2 × 15.0 mm2 was analyzed at a pixel size of 100 × 100 µm2 (14 043 mass scans), in less than 2 h. Natural products can be measured directly from native tissues, which inspires a broad use of LD-LTP MSI in plant chemistry studies.

Template for 3D Printing a Low-Temperature Plasma Probe.

Low-temperature plasma (LTP) ionization represents an emerging technology in ambient mass spectrometry. LTP enables the solvent-free direct detection of a broad range of molecules and mass spectrometry imaging (MSI). The low energy consumption and modest technical requirements of these ion sources favors their employment in mobile applications and as a means to upgrade existing mass analyzers. However, the broad adoption of LTP is hindered by the lack of commercial devices, and constructing personal devices is tricky. Improper setup can result in equipment malfunction or may cause serious damage to instruments due to strong electromagnetic fields or arcing. With this in mind, we developed a reproducible LTP probe, which is designed exclusively from commercial and 3D printed components. The plasma jet generated by the device has a diameter of about 200 µm, which is satisfactory for the ambient imaging of macroscopic samples. We coupled the 3D-LTP probe to an ion trap analyzer and demonstrated the functionality of the ion source by detecting organic and chemical compounds from pure reference standards, biological substances, and pharmaceutical samples. Molecules were primarily detected in their protonated form or as water/ammonium adducts. The identification of compounds was possible by standard collision-induced dissociation (CID) fragmentation spectra. The files necessary to reproduce the 3D parts are available from the project page ( http://lababi.bioprocess.org/index.php/3d-ltp ) under a dual license model, which permits reproduction of the probe and further community-driven development for noncommercial use ("peer production"). Our reproducible probe design thus contributes to a facilitated adaption and evolution of low-temperature plasma technologies in analytical chemistry.

Clinical effects and safety of different strategies for administering intravenous diuretics in acutely decompensated heart failure: a randomised clinical trial.

BACKGROUND: The mainstay of treatment for acutely decompensated heart failure (ADHF) is intravenous diuretic therapy either as a bolus or via continuous infusion. OBJECTIVES: We evaluated the clinical effects and safety of three strategies of intravenous furosemide administration used in emergency departments (EDs) for ADHF. METHODS: We performed a multicentre, randomised, parallel-group study. Patients with ADHF were randomised within 2 h of ED arrival to receive furosemide by continuous infusion (10 mg/h, group 1) or boluses (20 mg/6 h, group 2; or 20 mg/8 h, group 3). The primary end point was total diuresis, and secondary end points were dyspnoea, orthopnoea, extension of rales and peripheral oedema, blood pressure, respiratory and heart rates, and pulse oximetry, which were measured at arrival and 3, 6, 12 and 24 h after treatment onset. We also measured serum creatinine, sodium and potassium levels at arrival and after 24 h. RESULTS: Group 1 patients (n=36) showed greater 24 h diuresis (3705 mL) than those in groups 2 (n=37) and 3 (n=36) (3093 and 2670 mL, respectively; p<0.01), and this greater diuretic effect was observed earlier. However, no differences were observed among groups in the nine secondary clinical end points evaluated. Creatinine deterioration developed in 15.6% of patients, hyponatraemia in 9.2%, and hypokalaemia in 19.3%, with the only difference among groups observed in hypokalaemia (group 1, 36.3%; group 2, 13.5%; group 3, 8.3%; p<0.01). CONCLUSIONS: In patients with ADHF attending the ED, boluses of furosemide have a smaller diuretic effect but provide similar clinical relief, similar preservation of renal function, and a lower incidence of hypokalaemia than continuous infusion. TRIAL REGISTRATION NUMBER: This randomised trial was registered in the European Clinical Trial Database (EudraCT) with the reference number 2008-004488-20.

Association of intravenous digoxin use in acute heart failure with rapid atrial fibrillation and short-term mortality according to patient age, renal function, and serum potassium.

OBJECTIVE/BACKGROUND: Intravenous digoxin is still used in emergency departments (EDs) to treat patients with acute heart failure (AHF), especially in those with rapid atrial fibrillation. We investigated whether intravenous digoxin used to treat rapid atrial fibrillation in patients with AHF may influence mortality. METHODS: A secondary analysis of patients included in the Spanish EAHFE (Epidemiology of Acute Heart Failure in Emergency Departments) cohort, which includes patients diagnosed with AHF in 45 Spanish EDs. The relationships between age, estimated glomerular filtration rate, and potassium with 30-day mortality were investigated using restricted cubic spline models adjusted for relevant patient and episode variables. RESULTS: From the 19 947 patients included, we analyzed 2194 patients with AHF and rapid atrial fibrillation that not receiving digoxin at home, divided according to whether they were or were not treated with intravenous digoxin in the ED. The median age of the patients was 82 years (interquartile range=76-87), 61.4% were women and 65.2% had previous episodes of atrial fibrillation. Digoxin and no digoxin groups were formed by 864 (39.4%) and 1330 (60.6%) patients, respectively. There were 191 deaths within the 30-day follow-up period (8.9%), with no differences between patients receiving or not receiving digoxin (8.5 vs. 9.1%, P = 0.636). Although analysis of restricted cubic spline curves showed that death was associated with advanced age, worse renal function, and hypokalemia and hyperkalemia, the use of intravenous digoxin did not interact with any of these relationships (P = 0.156 for age, P = 0.156 for estimated glomerular filtration rate, P = 0.429 for potassium). CONCLUSION: The use of intravenous digoxin in the ED was not associated with significant changes in 30-day mortality, which was confirmed irrespective of patient age or the existence of renal dysfunction or serum potassium disturbances.

Decisions to admit vs. discharge patients with acute heart failure from the emergency department: consistency with a measure of severity of decompensation and the impact on prognosis. / Decisión de hospitalización o alta en pacientes con insuficiencia cardiaca aguda en urgencias, su adecuación con la gravedad de la descompensación e impacto pronóstico.

OBJECTIVES: To analyze the consistency between decisions to discharge or admit patients with acute heart failure (AHF) treated in emergency departments (EDs) and the level of risk of adverse events, and to analyze the impact of decisions to discharge patients. MATERIAL AND METHODS: Prospective study of baseline clinical data collected from patients diagnosed with AHF in 16 Spanish emergency departments. Patients were stratified by severity of decompensated AHF based on MEESSI assessment (Multiple Estimation of Risk Based on the Spanish Emergency Department Score). The distribution of severity was described for patients who were hospitalized (overall and for departments receiving the largest number of admissions) and for discharged patients. We analyzed the data for discharged patients for associations with the following quality-of-care indicators: all-cause mortality of less than 2% at 30 days, revisits to the ED for AHF in less than 10% of patients within 7 days of discharge, and revisits to the ED or admission for AHF in less than 20% within 30 days of discharge. RESULTS: We included 2855 patients with a median (interquartile range) age of 84 (76-88) years. Fifty-four percent were women, 1042 (36.5%) were classified as low risk, 1239 (43.4%) as intermediate risk, 301 (10.5%) as high risk, and 273 (9.6%) as very high risk. Thirty-day mortality rates by level of low to very high risk were 1.9%, 9.3%, 15.3%, and 38.4%, respectively. One-year mortality rates by risk level were 15.4%, 35.6%, 52.0%, and 74.2%. Admission rates by risk level were 62.2%, 77.4%, 87.0%, and 88.3%. Overall, 47.1% o patients discharged from the ED were in the 3 higher-risk categories (intermediate to very high), and 30.7% were in the lowest risk category. The 5 hospital areas receiving the most admissions, in order of lowest-to-highest risk classification, were internal medicine, the short-stay unit, cardiology, intensive care, and geriatrics. Rates and 95% CIs for quality-of-care indicators in patients discharged from EDs were as follows: 30-day mortality, 4.3% (3.0%-6.1%); ED revisits within 7 days, 11.4% (9.2%-14.0%), and ED revisits or admissions within 30 days, 31.5% (28.0%-35.1%). In patients classified as low risk on ED discharge, these percentages were lower, as follows, respectively: 0.5% (0.1%-1.8%), 10.5% (7.6%-14.0%), and 29.5% (26.6%-32.6%). CONCLUSION: We detected disparity between severity of AHF decompensation and the decision to discharge or admit patients. Outcomes in patients discharged from EDs do not reach the recommended quality-of-care standards. Reducing inconsistencies between severity of decompensation and ED decisions could help to improve quality targets.

OBJETIVO: Analizar cómo se ajusta la decisión de ingreso o alta del paciente con insuficiencia cardiaca aguda (ICA) atendido en urgencias a su riesgo de evento adverso, así como su impacto en el pronóstico en aquellos dados de alta desde urgencias. METODO: Se recogieron datos basales y clínicos de pacientes diagnosticados de ICA en 16 servicios de urgencias españoles. Los pacientes se estratificaron según la gravedad de la descompensación mediante la escala MEESSI y se analizó la distribución de dicha gravedad en hospitalizados (en conjunto, e individualmente para los servicios con mayor número de hospitalizaciones) y dados de alta desde urgencias. En este último grupo, se analizó el cumplimiento de los siguientes indicadores de calidad: mortalidad por cualquier causa a 30 días ( 2%), reconsulta a urgencias por ICA a 7 días posalta ( 10%), y reconsulta a urgencias u hospitalización por ICA a 30 días posalta ( 20%). RESULTADOS: Se incluyeron 2.855 pacientes (edad mediana = 84 años, RIC = 76-88; mujeres = 54%): 1.042 pacientes (36,5%) de riesgo bajo, 1.239 (43,4%) intermedio, 301 (10,5%) alto y 273 (9,6%) muy alto. La mortalidad a 30 días por categorías de riesgo fue 1,9%, 9,3%, 15,3% y 38,4%, respectivamente; la mortalidad al año 15,4%, 35,6%, 52,0% y 74,2%; y la hospitalización 62,2%, 77,4%, 87,0% y 88,3%. El 47,1% de pacientes dados de alta de urgencias tenía un riesgo incrementado (intermedio, alto o muy alto) y el 30,7% de hospitalizados eran de bajo riesgo. La gravedad de la descompensación según el servicio de hospitalización se incrementaba en el siguiente orden: medicina interna, corta estancia, cardiología, intensivos y geriatría. El 4,3% de pacientes dados de alta de urgencias (IC 95%: 3,0-6,1) falleció a los 30 días, el 11,4% (9,2-14,0) reconsultó en urgencias a los 7 días, y el 31,5% (28,0-35,1) reconsultó en urgencias o se hospitalizó a los 30 días. Si sólo se consideran los pacientes dados de alta de bajo riesgo, estos porcentajes descienden al 0,5% (0,1-1,8), 10,5% (7,6-14,0) y 29,5% (26,6-32,6), respectivamente. CONCLUSIONES: Existe disparidad entre la gravedad de la descompensación y la decisión en urgencias de hospitalizar o dar de alta a los pacientes con ICA. Los resultados que se obtienen en los pacientes dados de alta desde urgencias no alcanzan los estándares de calidad recomendados. Disminuir las incongruencias entre gravedad de la descompensación y toma de decisión podría contribuir a cumplir con estos estándares.

Use of digoxin in the emergency department to treat patients with acute heart failure and its impact on short-term outcomes. / Uso de digoxina endovenosa en urgencias para tratar pacientes con insuficiencia cardiaca aguda y su impacto en la evolución a corto plazo.

OBJECTIVES: To analyze factors related to the use of digoxin to treat patients with acute heart failure (AHF) in emergency departments (EDs) and the impact of digoxin treatment on short-term outcomes. MATERIAL AND METHODS: We included patients diagnosed with AHF in 45 Spanish EDs. The patients, who were not undergoing long-term treatment for heart failure, were classified according to whether or not they were given intravenous digoxin in the ED. Fifty-one patient or cardiac decompensation episode variables were recorded to profile ED patients treated with digoxin. Outcome variables studied were the need for hospital admission, prolonged stay in the ED (> 24 hours) for discharged patients, prolonged hospitalization (> 7 days) for admitted patients, and all-cause in-hospital or 30-day mortality. The associations between digoxin treatment and the outcomes were studied with odds ratios (ORs) adjusted for patient and AHF episode characteristics. RESULTS: Data for 15 549 patients (median age, 83 years; 55% women) were analyzed; 1430 (9.2%) were treated with digoxin. Digoxin was used more often in women, young patients, and those with better New York Heart Association (NYHA) classifications but more severe cardiac decompensation, especially if the trigger was atrial fibrillation with rapid ventricular response. Admissions were ordered for 75.4% of the patients overall (81.6% of digoxin-treated patients vs 74.8% of nontreated patients; P .001). The ED stay was prolonged in 38.3% of patients discharged from the ED (52.9% of digoxin-treated patients vs 37.2% of nontreated patients; P .001). The duration of hospital stay was prolonged in 48.1% (digoxin-treated, 49.3% vs 47.9%; P = .385). In-hospital mortality was 7.2% overall (6.9% vs 7.2%, P= .712), and 30-day mortality was 9.7% (9.3% vs 9.7%, P = .625). ED use of digoxin was associated with a prolonged stay in the department (adjusted OR, 1.883; 95% CI, 1.359-2.608) but not with hospitalization or mortality. CONCLUSION: Digoxin continues to be used in one out of ten ED patients who are not already on long-term treatment with the drug. Digoxin use is associated with cardiac decompensation triggered by atrial fibrillation with rapid ventricular response, younger age, women, and patients with better initial NYHA function status but possibly more severe decompensation. Digoxin use leads to a longer ED stay but is safe, as it is not associated with need for admission, prolonged hospitalization, or short-term mortality.

OBJETIVO: Analizar los factores relacionados con el uso de digoxina en urgencias en pacientes con insuficiencia cardiaca aguda (ICA) y el impacto pronóstico a corto plazo. METODO: Se incluyeron pacientes diagnosticados de ICA en 45 servicios de urgencias españoles sin tratamiento crónico con digoxina, los cuales se dividieron según recibiesen digoxina endovenosa en urgencias o no. Se recogieron 51 variables relativas al paciente o al episodio de descompensación y se investigó el perfil del paciente tratado con digoxina en urgencias. Como variables evolutivas se investigaron la necesidad de ingreso, la estancia en urgencias prolongada (> 24 horas) en dados de alta y la hospitalización prolongada (> 7 días) en ingresados, y la mortalidad intrahospitalaria y a 30 días por cualquier causa. Se analizó si el tratamiento con digoxina se asoció a diferencias evolutivas, de forma cruda y ajustada a las características del paciente y el episodio de ICA. RESULTADOS: Se analizaron 15.549 pacientes (mediana = 83 años, mujeres = 55%), de los que 1.430 (9,2%) fueron tratados con digoxina. La digoxina se utilizó más en mujeres, pacientes jóvenes, en mejor clase funcional de la New York Heart Association (NYHA), pero con descompensaciones más graves y, sobre todo, cuando existía una fibrilación auricular (FA) con respuesta ventricular rápida como desencadenante. Se hospitalizó el 75,4% de pacientes (más frecuente en tratados con digoxina; 81,6% vs 74,8%, p 0,001), tuvo estancia prolongada en urgencias el 38,3% (52,9% vs 37,2%, p 0,001), hospitalización prolongada el 48,1% (49,3% vs 47,9%, p = 0,385), mortalidad intrahospitalaria el 7,2% (6,9% vs 7,2%, p = 0,712) y a 30 días el 9,7% (9,3% vs 9,7%, p = 0,625). El modelo ajustado mostró que el uso de digoxina en urgencias sólo se asoció con estancia prolongada en urgencias (OR = 1,883, IC 95% = 1,359-2,608), pero no con la necesidad de ingreso, hospitalización prolongada o mortalidad. CONCLUSIONES: La digoxina continúa utilizándose en uno de cada 10 pacientes con ICA atendidos en urgencias que no utilizaban este fármaco de manera habitual. Su uso se relaciona con un paciente cuya ICA ha sido descompensada por una FA con respuesta ventricular rápida, más joven y más frecuentemente mujer, en mejor clase funcional de la NYHA basal y con una descompensación posiblemente más grave. El uso de digoxina conlleva una estancia en urgencias más prolongada, pero su uso es seguro, pues no se asocia a la necesidad de ingreso, hospitalización prolongada o mortalidad a corto plazo.

Build, Share and Remix: 3D Printing for Speeding Up the Innovation Cycles in Ambient Ionisation Mass Spectrometry (AIMS).

Ambient ionisation mass spectrometry (AIMS) enables studying biological systems in their native state and direct high-throughput analyses. The ionisation occurs in the physical conditions of the surrounding environment. Simple spray or plasma-based AIMS devices allow the desorption and ionisation of molecules from solid, liquid and gaseous samples. 3D printing helps to implement new ideas and concepts in AIMS quickly. Here, we present examples of 3D printed AIMS sources and devices for ion transfer and manipulation. Further, we show the use of 3D printer parts for building custom AIMS sampling robots and imaging systems. Using 3D printing technology allows upgrading existing mass spectrometers with relatively low cost and effort.

In Vivo Low-Temperature Plasma Ionization Mass Spectrometry (LTP-MS) Reveals Regulation of 6-Pentyl-2H-Pyran-2-One (6-PP) as a Physiological Variable during Plant-Fungal Interaction.

Volatile organic compounds (VOCs) comprises a broad class of small molecules (up to ~300 g/mol) produced by biological and non-biological sources. VOCs play a vital role in an organism's metabolism during its growth, defense, and reproduction. The well-known 6-pentyl-α-pyrone (6-PP) molecule is an example of a major volatile biosynthesized by Trichoderma atroviride that modulates the expression of PIN auxin-transport proteins in primary roots of Arabidopsis thaliana during their relationship. Their beneficial relation includes lateral root formation, defense induction, and increased plant biomass production. The role of 6-PP has been widely studied due to its relevance in this cross-kingdom relationship. Conventional VOCs measurements are often destructive; samples require further preparation, and the time resolution is low (around hours). Some techniques enable at-line or real-time analyses but are highly selective to defined compounds. Due to these technical constraints, it is difficult to acquire relevant information about the dynamics of VOCs in biological systems. Low-temperature plasma (LTP) ionization allows the analysis of a wide range of VOCs by mass spectrometry (MS). In addition, LTP-MS requires no sample preparation, is solvent-free, and enables the detection of 6-PP faster than conventional analytical methods. Applying static statistical methods such as Principal Component Analysis (PCA) and Discriminant Factorial Analysis (DFA) leads to a loss of information since the biological systems are dynamic. Thus, we applied a time series analysis to find patterns in the signal changes. Our results indicate that the 6-PP signal is constitutively emitted by T. atroviride only; the signal shows high skewness and kurtosis. In A. thaliana grown alone, no signal corresponding to 6-PP is detected above the white noise level. However, during T. atroviride-A. thaliana interaction, the signal performance showed reduced skewness and kurtosis with high autocorrelation. These results suggest that 6-PP is a physiological variable that promotes homeostasis during the plant-fungal relationship. Although the molecular mechanism of this cross-kingdom control is still unknown, our study indicates that 6-PP has to be regulated by A. thaliana during their interaction.

Circadian oscillations in Trichoderma atroviride and the role of core clock components in secondary metabolism, development, and mycoparasitism against the phytopathogen Botrytis cinerea.

Circadian clocks are important for an individual's fitness, and recent studies have underlined their role in the outcome of biological interactions. However, the relevance of circadian clocks in fungal-fungal interactions remains largely unexplored. We sought to characterize a functional clock in the biocontrol agent Trichoderma atroviride to assess its importance in the mycoparasitic interaction against the phytopathogen Botrytis cinerea. Thus, we confirmed the existence of circadian rhythms in T. atroviride, which are temperature-compensated and modulated by environmental cues such as light and temperature. Nevertheless, the presence of such molecular rhythms appears to be highly dependent on the nutritional composition of the media. Complementation of a clock null (Δfrq) Neurospora crassa strain with the T. atroviride-negative clock component (tafrq) restored core clock function, with the same period observed in the latter fungus, confirming the role of tafrq as a bona fide core clock component. Confrontation assays between wild-type and clock mutant strains of T. atroviride and B. cinerea, in constant light or darkness, revealed an inhibitory effect of light on T. atroviride's mycoparasitic capabilities. Interestingly, when confrontation assays were performed under light/dark cycles, T. atroviride's overgrowth capacity was enhanced when inoculations were at dawn compared to dusk. Deleting the core clock-negative element FRQ in B. cinerea, but not in T. atroviride, was vital for the daily differential phenotype, suggesting that the B. cinerea clock has a more significant influence on the result of this interaction. Additionally, we observed that T. atroviride clock components largely modulate development and secondary metabolism in this fungus, including the rhythmic production of distinct volatile organic compounds (VOCs). Thus, this study provides evidence on how clock components impact diverse aspects of T. atroviride lifestyle and how daily changes modulate fungal interactions and dynamics.

The emerging role of 3D-printing in ion mobility spectrometry and mass spectrometry.

3D-printing is revolutionizing the rapid prototyping in analytical chemistry. In the last few years, we observed the development of 3D-printed components for ion studies, such as ion sources, ion transfer and ion mobility spectrometry (IMS) devices. Often, 3D-printed gadgets add functions to existing mass spectrometry (MS) systems. Custom adapters improve the sensibility for coupling with ambient ionization and upstream chromatography methods, and sample preparation units optimize the following MS analyses. Besides, 3D-printer parts are suitable for constructing custom analytical robots and mass imaging systems. Some of those assemblies implement new concepts and are commercially not available. An essential aspect of using 3D-printing is the fast turnover of design improvements, which is motivated by permissive licenses. The easy reproducibility and exchange of ideas lead to a community-driven development, which is accompanied by economic advantages for public research and education.

Analysis of standards of quality for outcomes in acute heart failure patients directly discharged home from emergency departments and their relationship with the emergency department direct discharge rate.

OBJECTIVE: Experts recommended that direct discharge without hospitalization (DDWH) for emergency departments (EDs) able to observe acute heart failure (AHF) patients should be >40%, and these discharged patients should fulfil the following outcome standards: 30-day all-cause mortality <2% (outcome A); 7-day ED revisit due to AHF < 10% (outcome B); and 30-day ED revisit/hospitalization due to AHF < 20% (outcome C). We investigated these outcomes in a nationwide cohort and their relationship with the ED DDWH percentage. METHODS: We analyzed the EAHFE registry (includes about 15% of Spanish EDs), calculated DDWH percentage of each ED, and A/B/C outcomes of DDWH patients, overall and in each individual ED. Relationship between ED DDWH and outcomes was assessed by linear and quadratic regression models, non-weighted and weighted by DDWH patients provided by each ED. RESULTS: Among 17,420 patients, 4488 had DDWH (25.8%, median ED stay = 0 days, IQR = 0-1). Only 12.9% EDs achieved DDWH > 40%. Considering DDWH patients altogether, outcomes A/C were above the recommended standards (4.3%/29.4%), while outcome B was nearly met (B = 10.1%). When analyzing individual EDs, 58.1% of them achieved the outcome B standard, while outcomes A/C standards were barely achieved (19.3%/9.7%). We observed clinically relevant linear/quadratic relationships between higher DDWH and worse outcomes B (weighted R2 = 0.184/0.322) and C (weighted R2 = 0.430/0.624), but not with outcome A (weighted R2 = 0.002/0.022). CONCLUSIONS: The EDs of this nationwide cohort do not fulfil the standards for AHF patients with DDWH. High DDWH rates negatively impact ED revisit or hospitalization but not mortality. This may represent an opportunity for improvement in better selecting patients for early ED discharge and in ensuring early follow-up after ED discharge.