Viruses have consistently posed a significant threat to global health, varying in their effect from mild asymptomatic cases to full-blown incapacitating illnesses. India, a country with a tremendous population of over 1.3 billion, encounters unique challenges when managing public health crises, such as the recent re-emergence of the deadly zoonotic Nipah virus (NiV) in Kerala. Our commentary highlights the history of NiV outbreaks in light of the two primary pathways of virus transmission, animal-to-human and human-to-human. We discuss common presenting symptoms of NiV and risk factors contributing to its spread, proposing possible measures to tackle the current challenges in timely diagnosis and infection control. Owing to its high mutation and mortality rate, the NiV outbreak could have potentially transitioned into the next global pandemic, which calls for the implementation of stringent policies and infective protocols by the government and health authorities to curb any future outbreaks.

Background: Serum allergen-specific immunoglobulins E (IgE) play a key role in allergy diagnosis along with clinical history and physical examination. Nowadays, allergen multiplex assays allow complex polyallergic cases to be solved as they assess up to 300 allergen-specific IgE. Recently, machine learning has emerged as a trending tool in medicine. The aim was to build a nationwide, open-access database to create an algorithm that could predict allergy diagnosis, severity, category (airborne, food, venom) and culprit allergens. Methods: A retrospective national database was created by the French Society of Allergology in collaboration with AllergoBioNet and the Health Data Hub. Collected data were de-identified patient profiles with five demographic items, twenty clinical items and sIgE results of one allergen multiplex assay. An international crowdsourced machine learning competition was hosted by the Trustii.io platform. Criteria for algorithm evaluation were the F-score (a measure of a model’s accuracy on a dataset) and external validation on patient profiles outside the database (80%-20%, respectively). Results: Data were collected from 4271 patient files. Two hundred and ninety-two data scientists competed with 3135 algorithms. The best F-scores were comprised between 78% and 80%. Models associated with the highest F-scores used gradient boosting classifiers such as LightGBM, CatBoost, XGBoost adapted for tabular datasets with categorical features. Conclusions: We report here the first artificial intelligence models applied to allergen multiplex arrays interpretation in a nationwide real-world database built to be open access. With F-scores close to 80%, the French Allergen Chip Challenge paves the way for a diagnostic prediction tool for practicing allergists.

Objective To investigate the association between postpartum haemorrhage (PPH) and subsequent cardiovascular disease. Design Population-based retrospective cohort study, using record linkage between Aberdeen Maternity and Neonatal Databank (AMND) and Scottish healthcare datasets Setting Grampian region, Scotland Population or Sample 70,904 women who gave birth after 24 weeks of gestation, 1986-2016 Methods We used extended Cox regression models to investigate the association between PPH in any first or later births and subsequent cardiovascular disease, adjusted for sociodemographic, medical, and pregnancy and birth-related factors. Main outcome measures Cardiovascular disease identified from prescription of selected cardiovascular medications, hospital discharge records or death from cardiovascular disease. Results Compared with not having a PPH, having at least one PPH was associated with an increased risk of developing cardiovascular disease in the first year after birth [adjusted hazard ratio (aHR) 1.96, 95% confidence interval (CI) 1.51-2.53, p<0.001]. The association was attenuated over time, but strong evidence of increased risk remained 2-5 years (aHR 1.19, 95% CI 1.11-1.30, p<0.001) and 6-15 years after giving birth (aHR 1.17, 95% CI 1.05-1.30, p=0.005), with the direction of association reversed beyond 15 years (aHR 0.64, 95% CI 0.55-0.75, p<0.001). Conclusions Compared with women who have never had a PPH, women who have had at least one episode of PPH are twice as likely to develop cardiovascular disease in the first year after birth and some increased risk persists for up to 15 years. Keywords Postpartum haemorrhage, cardiovascular disease, health outcomes, Scottish data

Today’s electricity systems need to be more resilient, not only in the face of ever-increasing loads, but also with the accelerating penetration of renewable energy. However, due to environmental constraints and ever-increasing loads, these systems are often operated beyond their thermal capacity. When operating at the limit of their capacity, electrical systems can be affected by voltage and line instabilities. Various stability indices have been proposed in the literature for monitoring and predicting network stability, but their effectiveness is not always satisfactory. The present work has been devoted to the development of a relevant and effective analytical tool for the prediction of network collapse. The effectiveness and applicability of this tool were validated using standard IEEE 14 and 30 bus systems. In fact, this tool, known as the Complex Stability Index for Transmission Line (CSITL), performs better than traditional line voltage stability indices. At base load, line 1-5 of the IEEE 14 bus system is the most critical, carrying an apparent power of 78 MVA, i.e. 78% of the limit. For this line, the CSITL, NCPI and FVSI indices are 0.9963, 0.1826 and 0.0629 respectively. For the most critical line of the IEEE 30 bus system at base load, these indices are 0.7229, 0.0849 and 0.0419 respectively. The application of CSITL to the 14-bus and 30-bus test networks shows that it remains a powerful and excellent tool for effective and efficient management of transport networks, even in a disrupted context.

This paper proposes a new methodology for sensitivity analysis evaluation, fast and with high precision of the electric potential distribution near the transmission lines (TL’s). The TL is modeled by the finite element method and the sensitivity of the cable positions is obtained using the adjoint method. The sensitivity of the objective function during the optimization process by using methods based on gradient information is obtained by using the adjoint method. The exact sensitivity obtained by the adjoint method concerning the numeric model of the TL’s results in new geometries of the bundles conductors with high surge impedance loading. These geometries are not possible to get using analytic models. The sensitivities of a large number of conductors by phase are obtained with high precision and very low computational cost using adjoint sensitivities, which are independent of the number of design variables. The central finite difference (CFD) method is used to calculate the sensitivities and to validate the adjoint method. With this methodology, the FEM model of the TL can be used during the optimization process without compromising the required computational processing time.

A document by Somesh Tiwari. Click on the document to view its contents.

A document by Adrien Osakwe. Click on the document to view its contents.

Secondary forests represent significant proportions of global forest cover, with over 65% of forests in Asia classified as regenerating. While succession has been studied extensively in temperate systems, trajectories of sub-tropical forest succession remain poorly characterized in highly disturbed, urban-adjacent forests. Investigating the additive beta diversity subcomponents of Turnover and Nestedness may reveal community assembly mechanisms driving secondary succession. The present study investigated plant community assembly along a successional gradient from 7 to 70 years following the onset of succession in secondary sub-tropical forests in Hong Kong. Plant survey data for 28 plots were analysed, generating additive Simpsons and Nestedness beta diversity metrics as subcomponents of Sorenson Beta Diversity. Dissimilarity matrices were generated and modelled as a function of transformed environmental matrices of forest plant community age (years following onset of secondary succession), elevation (metres), inter-community distance (metres), soil moisture saturation (%) and soil organic carbon (g kg-1). Generalized dissimilarity models were generated for plant species Turnover and Nestedness. Nonmetric Multidimensional Scaling of plant communities was conducted with Bray-Curtis dissimilarity matrices. Our findings indicate that elevation was the primary driver of plant species Turnover, while age and inter-community distance played less prominent roles. Models of Nestedness found that plot age and soil moisture saturation were the sole drivers of Nestedness patterns in plant communities. While models of Turnover were robust, the low explanatory power of Nestedness models suggest additional unobserved factors driving patterns of plant community Nestedness during secondary succession. Turnover patterns suggest a deterministic model of community assembly, with strong patterns of species replacement between Lowland and Montaine forest types, as well as between successional age classes.

Understanding trees' growing season timing is crucial for comprehending their role in terrestrial ecosystems, including carbon dynamics. Our current determination of the growing season, based on species- and method-specific interpretations, and our understanding of the main drivers triggering the growing season yield varied results. Rethinking the growing season timing could have far-reaching implications, potentially reshaping our understanding of climate change's effect on tree growth, their carbon sequestration and future geographical distribution.

Recent theoretical advances in the One Health approach propose that greater attention should be paid to cancer pathologies due to their potential to render hosts more susceptible to infectious agents, potentially transforming them into super-spreaders within ecosystems. However, this hypothesis lacks experimental validation. Using a community of Hydra species and a commensal ciliate species (Kerona pediculus) that colonizes them, we tested whether tumoral polyps of H. oligactis, compared to healthy ones, played an amplifying role in ciliate load, potentially resulting in higher likelihood of infection for other community members through spillovers. Results revealed a higher proliferation rate of ciliates on tumoral polyps compared to healthy ones, leading to infection of other hydras, albeit with varying spillover magnitudes among recipient species. This study is the first proof of concept that tumoral individuals within communities could act as super-spreaders of symbionts within and between species, influencing biotic interactions and dynamics in ecosystems.

The total iridoid glycoside extract of Lamiophlomis rotata (IGLR) has been proven to be the main pharmacological ingredient for wound healing; however, it is still unclear, which compounds in the extract are responsible for this effect. We developed and validated a mass spectrometry imaging (MSI) method to reveal the relationship between phytochemical components and the pharmacological efficacy in IGLR. Shanzhiside methyl (SM) ester, 8-O-acetylshanzhiside methyl ester (ASM), and Phlorigidoside C (PhC) have been identified as quality markers in IGLR to accelerate wound healing by MSI method. As per MSI data with UMAP manifold analysis, these compounds overlapped in the same class with endogenous metabolites (lactate, citrate and succinate). In addition, UPLC-Q/TOF-MSn coupled with multivariate analyses for skin tissues in the normal and wound groups further confirmed the results. Furthermore, MSI data from livers and kidneys revealed that SM, ASM, and PhC absorption significantly increased, whereas their elimination rates remarkably decreased in the injured group. Collectively, the overall data demonstrated that SM, ASM, and PhC selectively increased in the new granulation tissue and that the bioavailability of these three quality markers was remarkably improved in the wound group after continuous gavage for 7 days. This protocol can be applied to reveal the relationship between phytochemical components and the pharmacological efficacy of other iridoid glycoside extracts.

Sequencing the tyrosine phosphoproteome using MS-based proteomics is challenging due to the low abundance of tyrosine phosphorylation in cells, a challenge compounded in scarce samples like primary cells or clinical samples. The broad-spectrum optimization of selective triggering (BOOST) method was recently developed to increase phosphotyrosine sequencing in low protein input samples by leveraging tandem mass tags (TMT), phosphotyrosine enrichment, and a phosphotyrosine-loaded carrier channel. Here, we demonstrate the viability of BOOST in T cell receptor (TCR)-stimulated primary murine T cells by benchmarking the accuracy and precision of the BOOST method and discerning significant alterations in the phosphoproteome associated with receptor stimulation. Using 1 milligram of protein input (about 20 million cells) and BOOST, we identify and precisely quantify more than 2,000 unique pY sites compared to about 300 unique pY sites in non-BOOST control samples. We show that although replicate variation increases when using the BOOST method, BOOST does not jeopardise quantitative precision or the ability to determine statistical significance for peptides measured in triplicate. Many pY previously uncharacterised sites on important T cell signalling proteins are quantified using BOOST, and we identify new TCR responsive pY sites observable only with BOOST. Finally, we determine that the phase-spectrum deconvolution method on Orbitrap instruments can impair pY quantitation in BOOST experiments.

Objective: The non-invasive right ventricular pressure-strain loop (PSL) represents a novel method for the quantitative assessment of right ventricular myocardial function. Given that atrial septal defect (ASD) is a prevalent congenital heart anomaly associated with right ventricular volume overload, this study aims to quantitatively assess the myocardial function of the right ventricle in ASD patients pre- and post-occlusion by noninvasive right ventricular PSL. Methods: This study included thirty-six patients diagnosed with secundum atrial septal defect (ASD group) and thirty healthy adults (control group). We compared conventional right ventricular echocardiographic parameters, right ventricular strain, and myocardial work in the ASD group before occlusion, two days post-occlusion, and three months post-occlusion, with those in the control group. Results: Prior to and two days following occlusion, the ASD group exhibited higher right ventricular global work index (RVGWI), right ventricular global wasted work (RVGWW), and right ventricular global constructive work (RVGCW) compared to the control group ( P < 0.05). Within the ASD group, post-occlusion, RVGWI, RVGCW, and RVGWW values were significantly reduced compared to pre-occlusion values ( P < 0.001). Furthermore, RVGWI and RVGCW showed a significant decrease three months after occlusion compared to two days post-occlusion ( P < 0.05). Multivariate regression analysis identified ASD diameter and pulmonary artery systolic pressure (PASP) as independent predictors of RVGWI( β = 0.405, P < 0.001; β=2.307， P=0.037) and RVGCW（β=0.350, P＜0.001; β=1.967, P=0.023). Conclusions: The non-invasive right ventricular PSL effectively demonstrates the alterations in right ventricular myocardial function in ASD patients, pre- and post-occlusion. The metrics of right ventricular myocardial work (RVMW) offer a novel indicator for evaluating right ventricular myocardial function in these patients. Moreover, ASD diameter and PASP emerge as independent determinants of RVGWI and RVGCW.

The online trend of the manosphere and feminist discourse on social networks requires a holistic measure of the level of sexism in an online community. This indicator is important for policymakers and moderators of online communities (e.g., subreddits) and computational social scientists, either to revise moderation strategies based on the degree of sexism or to match and compare the temporal sexism across different platforms and communities with real-time events and infer social scientific insights. In this paper, we build a model that can provide a comparable holistic indicator of toxicity targeted toward male and female identity and male and female individuals. Despite previous supervised NLP methods that require annotation of toxic comments at the target level (e.g. annotating comments that are specifically toxic toward women) to detect targeted toxic comments, our indicator uses supervised NLP to detect the presence of toxicity and unsupervised word embedding association test to detect the target automatically. We apply our model to gender discourse communities (e.g., r/TheRedPill, r/MGTOW, r/FemaleDatingStrategy) to detect the level of toxicity toward genders (i.e., sexism). Our results show that our framework accurately and consistently (93% correlation) measures the level of sexism in a community. We finally discuss how our framework can be generalized in the future to measure qualities other than toxicity (e.g. sentiment, humor) toward general-purpose targets and turn into an indicator of different sorts of polarizations.

Peptides play an indispensable role in various biological functions and show therapeutic potential. The forest musk deer, an important source of musk, is a focal species in traditional medicine. While cell culture techniques offer a sustainable alternative for musk production, the complexity of peptide components produced by these methods remains poorly understood. To bridge this knowledge gap, we compared the peptidomic profiles of secretions from cultured musk gland cells with those of natural musk cells using the EASY-nLC 1000 UHPLC (Ultra-High Performance Liquid Chromatography) system. Our analysis revealed similarities and notable differences between the peptide profiles of cultured cell secretions and those of natural musk, with significant implications for the biosynthesis and chemical composition of musk. This study provides critical insights into the peptidomic differences between cultured cell secretions and natural musk, highlighting the challenges and potential of using cell culture techniques for the sustainable production of musk components. Future research should focus on refining conditions to more closely emulate the natural biosynthetic pathways of musk peptides.

Title: Assessment of sIgE to rLep d 2 for DetectingLepidoglyphus destructor SensitizationConclusion: The novel recombinant allergen rLep d 2 exhibits excellent specificity, although its sensitivity is lower compared to specific IgE tests and skin prick tests using Lepidoglyphus destructor . Its additional diagnostic utility for respiratory allergies related to L. destructor is minimal.To the Editor:Recently, rLep d 2 has been introduced to diagnose IgE-mediated allergy to Lepidoglyphus destructor. We aimed to analyze the sensitivity, specificity, and likelihood ratios of sIgE against rLep d 2.We retrospectively analyzed 95 sera of patients previously diagnosed with respiratory allergy to L destructor , to whom an IgE determination of L destructor had been requested. The protocol was approved by the Hospital Ethics Committee for Clinical Research (PI 2023/09/1425). Material and methods are specified in Supplementary material.Statistically significant differences were found between patients sensitized and not sensitized to L destructor . Patients with a sIgE positive to L destructor were younger, had a higher percentage of asthma and moderate/severe persistent rhinitis, and had higher levels of total IgE and sIgE to rLep d 2 and rDer p 2 than non-sensitized patients. (Table 1).There was a high correlation between L destructor and rLep d 2 (R=0.940, p<0.001), although no correlation was observed between L. destructor and r Der p 2 (R= 0.117, p= 0.260) (Figure S1).The sensitivity of sIgE to rLep d 2 was 71.64% (95% CI, 59.31-81.99), and specificity was 96.43% (95% CI, 81.65-99.91). PLR was 20.06 (95%CI, 2.91-138.28) and NLR 0.29 (95% CI, 0.20-0.43). The Receiver Operating Characteristic (ROC) curve for sIgE to rLep d 2 had an area under the curve of 0.931 (Figure S2). The results of the patients’ test are summarized in Figure 1.This is the first study to examine the accuracy of the commercially available major allergen rLep d 2 in a population of patients allergic and non-allergic to L destructor with rhinitis and/or asthma. Good sensitivity (71.64%), excellent specificity (96.43%), remarkable PLR (20.06) and NRL (0.29), and a noteworthy ROC result (0.931) were observed.Data analysis showed a high correlation between sIgE to rLep d 2 and sIgE to L destructor (0.94) (Figure S1A), much higher than that previously obtained by Johansson et al. (1), who used a non-commercial recombinant extract of Lep d 2, finding a correlation coefficient of 0.70. Additionally, the lack of correlation between sIgE to rDer p 2 and sIgE to L destructor , with a correlation coefficient of 0.117 (Figure S1B), agrees with the lack of cross-reactivity between group 2 allergens of L destructor andD pteronyssinus (2). Therefore, most patients who test positive for rLep d 2 and rDer p 2 can be considered co-sensitized.The sensitivity and specificity data for sIgE to rLep d 2 indicate that a positive result suggests sensitization to L. destructor . In contrast, a negative result does not necessarily rule out sensitization, as almost 30% of patients can still be sensitized to L destructor . The PLR of 20.06 provides robust evidence for L destructor allergy when rLep d 2 values are ≥0.35 kU/L. However, it is noteworthy that the ability to exclude L destructor allergy is weaker when rLep d 2 values fall below that threshold.Patients’ test results (Figure 1) suggest that both SPT and sIgE should be used when evaluating a patient with suspected allergy to L destructor . In addition, 19 patients had sIgE positive to L destructor but negative sIgE to rLep d 2. It could happen that some patients may have been sensitized to allergens other than Lep d 2. Accordingly, rLep d 2 should not be initially used when evaluating a patient with a suspected allergy to L destructor . Notwithstanding, sIgE against Lep d 2 might be helpful before initiating specific immunotherapy with L destructor (3).To conclude, despite an excellent specificity, determining sIgE to rLep d 2 does not seem to offer additional diagnostic value when compared SPTs and/or sIgE to L destructor .REFERENCESJohansson E, Eriksson TLJ, Olsson S, et al. Evaluation of Specific IgE to the Recombinant Group 2 Mite Allergens Lep d 2 and Tyr p 2 in the Pharmacia CAP System. Int Arch Allergy Immunol. 1999;120(1):43-49.Parvaneh S, Johansson E, Elfman LH, et al. An ELISA for recombinant Lepidoglyphus destructor, Lep d 2, and the monitoring of exposure to dust mite allergens in farming households. Clin Exp Allergy. 2002 Jan;32(1):80-6Ansotegui IJ, Melioli G, Canonica GW, et al. IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper. World Allergy Organ J. 2020 Feb 25;13(2):100080.

Alcohol consumption and high-fat diets often coincide in Western society, exerting negative synergistic effects on the liver. While many studies have demonstrated the impact of ALD and NAFLD on organ protein expression, none have offered a comprehensive view of the dysregulation at the level of the membrane proteome. In this study, we utilize peptidisc and solvent precipitation (SP4) methods to isolate and compare the membrane protein content of the liver with its unique biological functions. Using mice treated with a high-fat diet and ethanol in drinking water, we identified 1,563 liver proteins, with 46% predicted to have a transmembrane segment. Among these, 106 integral membrane proteins are dysregulated compared to the untreated sample. Gene ontology analysis reveals several dysregulated membrane processes associated with lipid metabolism, cell adhesion, xenobiotic processing, and mitochondrial membrane formation. Pathways related to cholesterol and bile acid transport are also mutually affected, suggesting an adaptive mechanism to counter the steatosis of the liver model. Our peptidisc-based membrane proteome profiling thus emerges as an effective way to gain insights into the role of the transmembrane proteome in disease development, warranting further in-depth analysis of the individual effect of the identified dysregulated membrane proteins.

Trade-offs are crucial for species divergence and reproductive isolation. Trade-offs between investment in growth versus defense against herbivores are implicated in tropical forest diversity. Empirically exploring the role of growth-defense trade-offs in closely related species’ reproductive isolation can clarify the eco-evolutionary dynamics through which growth-defense trade-offs contribute to diversity. Costus villosissimus and C. allenii are recently diverged, interfertile, and partially sympatric neotropical understory plant species primarily isolated by divergent habitat adaptation. This divergent adaptation involves differences in growth rate, which may constrain investment in defense. Here, we investigate growth-defense trade-offs and how they relate to the divergent habitat adaptation that isolates these species. We characterize leaf toughness and chemistry, evaluate the feeding preferences of primary beetle herbivores in controlled trials and field-based experiments, and investigate natural herbivory patterns. We find clear trade-offs between growth and defense: slower-growing C. allenii has tougher leaves and higher defensive chemical concentrations than faster-growing C. villosissimus. Costus villosissimus has rapid growth-based drought avoidance, enabling growth in drier habitats with few specialist herbivores. Therefore, growth-defense trade-offs mediate synergistic biotic and abiotic selection, causing the divergent habitat adaptation that prevents most interspecific mating between C. villosissimus and C. allenii. Our findings advance understanding of ecological speciation by highlighting the interplay of biotic and abiotic selection that dictates the outcome of trade-offs.

A document by Shumin Qin. Click on the document to view its contents.

Anthropogenic pressures such as hunting are increasingly driving the localized functional extinctions of all or most large and medium-sized wildlife species in tropical forests, a phenomenon broadly termed defaunation. Concurrently in these areas, smaller-bodied wildlife species benefit from factors such as competitive release and experience population increases. This transformation of the wildlife community can impact species interactions and ecosystem services such as seed dispersal and seed-mediated geneflow with far reaching consequences. Evidence for negative genetic effects following defaunation is well-documented in large-seeded plants that require large frugivores for long distance seed dispersal. However, how defaunation affects small-seeded (< 1.5cm diameter) plants, which are dispersed by frugivores with a wide range of body-sizes and responses to anthropogenic threats, is not well understood. To better understand the reach of defaunation’s impacts on tropical plant communities, we investigated spatial and genetic patterns in a hyperabundant small-seeded palm, Euterpe precatoria in three sites representing distinct defaunation levels. We found significantly higher fine-scale spatial genetic structure among nearest-neighbor seedlings in the defaunated site and in the recovering, partially defaunated site relative to the faunally-intact site. Defaunation was associated with shorter distances between seedlings and adults and lower genetic distance between adult and seedling cohorts. No effects were detected on inbreeding and genetic diversity; however, we caution that trends we detected indicate that defaunation influences the spatial distribution of genetic variation even in small-seeded plants that inherently have a broad suite of seed dispersal agents, and this could lead to negative downstream effects on genetic diversity.

We conducted a multicentre test-negative case-control study covering the period from October 2023 to January 2024 among adult patients aged ≥18 years hospitalised with severe acute respiratory infection in Europe. We provide early estimates of the effectiveness of the newly adapted XBB.1.5 COVID-19 vaccines against PCR-confirmed SARS-CoV-2 hospitalisation. Vaccine effectiveness was 48% overall, ranging between 68% at 14–29 days and 40% at 60–105 days post vaccination. The adapted XBB.1.5 COVID-19 vaccines conferred protection against COVID-19 hospitalisation in the first 3.5 months post vaccination, with VE >70% in older adults (≥65 years) up to 1 month post vaccination.

Adjunctive therapies to non-surgical periodontal treatment have significant advantages in susceptible patients as it helps to modulate the host immune response. In this study, we compare the effectiveness of oxygen releasing gel (BM) alone, or associated with photodynamic therapy (PDT), after scaling and root planning (SRP), as adjuvants in the treatment of ligature-induced experimental periodontitis (EP) in rats. Our findings indicate that treatment with BM, PDT, and BM+PDT groups at both 7 and 30 days resulted in decreased alveolar bone destruction in the furcation area of mandibular molars compared to the EP and SRP groups. At 30 days, the PDT and BM+PDT groups enhanced the resolution of inflammation by decreasing the inflammatory infiltrate and increasing alveolar bone neoformation. Treatment with BM gel alone also improves the repair of periodontal tissues but is less effective compared to PDT. Finally, combining BM with PDT appears to diminish the effects of PDT.

Background & Objectives: Supplemental oxygen and aerosol therapy may be used in combination as a treatment for neonates suffering from hypoxemia caused by respiratory diseases. Due to cost and lack of availability of oxygen cylinders in some countries, oxygen concentrators are a reported substitute. This study was designed to determine whether using an oxygen concentrator and low-flow oxygen therapy impacts aerosol drug delivery in a simulated spontaneously breathing neonate patient. Methods: A vibrating mesh nebuliser (VMN; Aerogen Solo) was used to aerosolise a 500µL dose of salbutamol. The aerosol was delivered via a nasal cannula to a neonate head model in combination with oxygen concentrator at gas flow rates of 0.2, 1.0 and 5.0 LPM and low-flow oxygen therapy at gas flow rates of 1.0, 4.0 and 5.0 LPM. The mass of drug in terms of emitted and tracheal doses were recorded. The impact of VMN operation and refill on circuit pressure in both systems was also measured. Results: The oxygen concentrator delivered a higher emitted dose than the low flow system, the largest emitted dose (%) being 20.58 ± 0.50% and 14.69 ± 0.89% respectively at 1.0 LPM , p = 0.018. The largest tracheal dose (%) was generated with the oxygen concentrator, 11.01 ± 0.29% at 5.0LPM compared to 9.66 ± 1.53% for low-flow oxygen therapy, p = 0.073. Refill and operation of the VMN did not impact the circuit pressure in either system. Conclusions: This study shows that the system used to provide combinational aerosol and supplemental oxygen therapy has a significant impact on the quantity of nebulised therapeutic delivered to the patient.

Introduction