Dual-fuelling in compression–ignition (CI) engines is a mode of combustion where a small pilot injection of high-cetane fuel (i.e. diesel) ignites a premixed high-octane fuel (i.e. methane) and air ...mixture. This allows conventional CI engines to lower their emissions of smoke and nitrogen oxides
(
NO
x
)
while maintaining their high thermal efficiencies. However, poor ignitability of the main fuel–air charge results in increased emissions of unburnt hydrocarbons (HC) and carbon monoxide (CO). Conventional pilot fuels such as diesel and biodiesel (methyl esters transesterified from raw plant oil) have been researched extensively in prior work, showing that in terms of performance and emissions they perform fairly similarly. This is because the physical, chemical and combustion properties of various methyl esters are comparable to those of conventional diesel. In order to reduce these emissions of HC and CO, alternative pilot fuels need to be considered. As fuels employed during normal CI engine operation, both dimethyl ether (DME, a gaseous CI engine fuel) and water-in-fuel emulsions (conventional biodiesel mixed with varying concentrations of water) have shown that they reduce smoke and
NO
x
emissions significantly, while improving combustion quality. In this work, the performance of DME and water-in-biodiesel emulsions as pilot fuels was assessed. It was seen that the water-in-biodiesel emulsions did not perform as well as expected, as increased HC and CO emissions coupled with a mild change in
NO
x
levels was encountered (compared to conventional pilot fuel, in this case neat biodiesel). The emulsions performed very poorly as pilot fuels below a certain BMEP threshold. DME, while producing higher levels of HC and CO than neat biodiesel, managed to reduce
NO
x
significantly compared to neat biodiesel. Emissions of HC and CO, while higher than neat biodiesel, were not as high as levels seen with the emulsions. Thermal efficiency levels were generally maintained with the liquid pilot fuels, with the DME pilot producing comparatively lower levels.
Texture modification has become one of the most common forms of intervention for dysphagia, and is widely considered important for promoting safe and efficient swallowing. However, to date, there is ...no single convention with respect to the terminology used to describe levels of liquid thickening or food texture modification for clinical use. As a first step toward building a common taxonomy, a systematic review was undertaken to identify empirical evidence describing the impact of liquid consistency and food texture on swallowing behavior. A multi-engine search yielded 10,147 non-duplicate articles, which were screened for relevance. A team of ten international researchers collaborated to conduct full-text reviews for 488 of these articles, which met the study inclusion criteria. Of these, 36 articles were found to contain specific information comparing oral processing or swallowing behaviors for at least two liquid consistencies or food textures. Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing: thicker liquids reduce the risk of penetration–aspiration, but also increase the risk of post-swallow residue in the pharynx. The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes. With respect to food texture, the literature pointed to properties of hardness, cohesiveness, and slipperiness as being relevant both for physiological behaviors and bolus flow patterns. The literature suggests a need to classify food and fluid behavior in the context of the physiological processes involved in oral transport and flow initiation.
Human Carbonic anhydrase IX (hCA IX) is found to be an essential biomarker for the treatment of hypoxic tumors in both the early and metastatic stages of cancer. Due to its active function in ...maintaining pH levels and overexpression in hypoxic conditions, hCA IX inhibitors can be a potential candidate specifically designed to target cancer development at various stages. In search of selective hCA IX inhibitors, we developed a pharmacophore model from the existing natural product inhibitors with IC50 values less than 50 nm. The identified hit molecules were then investigated on protein-ligand interactions using molecular docking experiments followed by molecular dynamics simulations. Among the zinc database 186 hits with an RMSD value less than 1 were obtained, indicating good contact with key residues HIS94, HIS96, HIS119, THR199, and ZN301 required for optimum activity. The top three compounds were subjected to molecular dynamics simulations for 100 ns to know the protein-ligand complex stability. Based on the obtained MD simulation results, binding free energies are calculated. Density Functional Theory (DFT) studies confirmed the energy variation between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO). The current study has led to the discovery of lead compounds that show considerable promise as hCA IX inhibitors and suggests that three compounds with special molecular features are more likely to be better-inhibiting hCA IX. Compound S35, characterized by a higher stability margin and a smaller energy gap in quantum studies, is an ideal candidate for selective inhibition of CA IX.
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•Pharmacophore model was developed in search of selective hCA IX inhibitors.•Molecular docking studies revealed 186 hits from zinc database.•Three lead compounds were identified based on molecular dynamics simulations.•Toxicity and ADME parameters were calculated for the lead molecules.•DFT studies identified compound S35 as an ideal candidate.
Hyperoxia-induced acute lung injury (HALI) is a key contributor to the pathogenesis of bronchopulmonary dysplasia (BPD) in neonates, for which no specific preventive or therapeutic agent is ...available. Here we show that lung micro-RNA (miR)-34a levels are significantly increased in lungs of neonatal mice exposed to hyperoxia. Deletion or inhibition of miR-34a improves the pulmonary phenotype and BPD-associated pulmonary arterial hypertension (PAH) in BPD mouse models, which, conversely, is worsened by miR-34a overexpression. Administration of angiopoietin-1, which is one of the downstream targets of miR34a, is able to ameliorate the BPD pulmonary and PAH phenotypes. Using three independent cohorts of human samples, we show that miR-34a expression is increased in type 2 alveolar epithelial cells in neonates with respiratory distress syndrome and BPD. Our data suggest that pharmacologic miR-34a inhibition may be a therapeutic option to prevent or ameliorate HALI/BPD in neonates.
The Airway Microbiome at Birth Lal, Charitharth Vivek; Travers, Colm; Aghai, Zubair H ...
Scientific reports,
08/2016, Letnik:
6, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Alterations of pulmonary microbiome have been recognized in multiple respiratory disorders. It is critically important to ascertain if an airway microbiome exists at birth and if so, whether it is ...associated with subsequent lung disease. We found an established diverse and similar airway microbiome at birth in both preterm and term infants, which was more diverse and different from that of older preterm infants with established chronic lung disease (bronchopulmonary dysplasia). Consistent temporal dysbiotic changes in the airway microbiome were seen from birth to the development of bronchopulmonary dysplasia in extremely preterm infants. Genus Lactobacillus was decreased at birth in infants with chorioamnionitis and in preterm infants who subsequently went on to develop lung disease. Our results, taken together with previous literature indicating a placental and amniotic fluid microbiome, suggest fetal acquisition of an airway microbiome. We speculate that the early airway microbiome may prime the developing pulmonary immune system, and dysbiosis in its development may set the stage for subsequent lung disease.
Accessing quality palliative care, especially at the end of life is vital in reducing physical and emotional distress and optimising quality of life. For people living in rural and remote Australia, ...telehealth services can be effective in providing access to after-hours palliative care. To review and map the available evidence on the use of telehealth in providing after-hours palliative care services in rural and remote Australia. Scoping review using Arksey and O'Malley methodological framework. Findings are reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Scopus, Web of Science, CINAHL Complete, Embase via Ovid, Emcare via Ovid, and Medline via Ovid databases were searched. Peer-reviewed studies and grey literature published in English from 2000 to May 2021 were included. Twelve studies were included in the review. Four main themes were identified: 1) Stakeholder perceptions of service; 2) benefits to services and users; 3) service challenges; and 4) recommendations for service improvement. Telehealth can connect patients and families with healthcare professionals and enable patients to continue receiving care at home. However, challenges relating to patients, service, staff skills, and experience need to be overcome to ensure the success and sustainability of this service. Improved communication and care coordination, better access to patient records, and ongoing healthcare professional education are required. Protocols, comprehensive policy documents and standardized operating procedures to guide healthcare professionals to provide after-hours palliative care is needed. Ongoing education and training for staff is crucial in managing patients' symptoms. Existing service gaps need to be explored and alternative models of after-hours palliative care need to be tested.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Idiopathic pulmonary fibrosis (IPF) is a fatal disease, and therapeutic agents have shown only modest efficacy. Epigenetic alterations contribute to the pathogenesis of IPF. The histone deacetylase ...inhibitor, suberoylanilide hydroxamic acid (SAHA), has been approved for clinical use in cancer; however, its potential efficacy in modulating fibroblast survival and lung fibrosis has not been extensively investigated. We investigated the effects of SAHA on apoptosis of primary IPF myofibroblasts and on injury-induced lung fibrosis in a murine model. SAHA-induced apoptosis of IPF myofibroblasts, an effect that was mediated, at least in part, by upregulation of the pro-apoptotic gene Bak and downregulation of the anti-apoptotic gene Bcl-xL. Alterations in the expression of these apoptosis-related genes were associated with histone modifications and changes in DNA methylation. In addition to the expected higher levels of histone acetylation in treated cells, we also detected changes in other histone modifications, such as histone methylation. In a murine model of bleomycin-induced pulmonary fibrosis, SAHA-treated mice displayed decreased lung fibrosis and improved lung function compared to the bleomycin only group. These results suggest that histone deacetylase inhibitors may offer a new therapeutic strategy in IPF by modulating myofibroblast susceptibility to apoptosis.
Multiple sensor systems are designed by varying aza-crown ether moiety in silicon quantum dots (SiQDs) for detecting individual Mg2+, Ca2+, and Mn2+ metal ions with significant selectivity and ...sensitivity. The detection limit of Mg2+, Ca2+, and Mn2+ can reach 1.81, 3.15, and 0.47 μM, respectively. Upon excitation of the SiQDs which are coordinated with aza-crown ethers, the photoinduced electron transfer (PET) takes place from aza-crown ether moiety to the valence band of SiQDs core such that the reduced probability of electron–hole recombination may diminish the subsequent fluorescence. The fluorescence suppression caused by such PET effect will be relieved after selective metal ion is added. The charge-electron binding force between the metal ion and aza-crown ether hinders the PET and thereby restores the fluorescence of SiQDs. The design of sensor system is based on the fluorescence “turn-on” of SiQDs while in search of the appropriate metal ion. For practical application, the sensing capabilities of metal ions in the live cells are performed and the confocal image results reveal their promising applicability as an effective and nontoxic metal ion sensor.
Objective
The aim of this study was to assess and correlate the serum and GCF levels of omentin with the periodontal status of rheumatoid arthritis (RA) patients with and without periodontitis.
...Methods
Forty‐four patients were divided into four groups: group H: 11 systemically and periodontally healthy subjects; group P: 11 systemically healthy subjects with periodontitis; group RA: 11 periodontally healthy subjects with rheumatoid arthritis and group RA + P: 11 rheumatoid arthritis subjects with periodontitis. Periodontal parameters (plaque index, modified gingival index, probing depth, and clinical attachment level) were recorded and serum and GCF samples were collected for the estimation of omentin using ELISA.
Results
The mean value of plaque index, modified gingival index, probing depth, and clinical attachment level were significantly higher whereas serum and GCF omentin levels were found to be decreased in group IV when compared to the other groups. The significant correlation was found between the serum and GCF omentin levels with all the periodontal parameters.
Conclusion
The omentin level in serum and GCF was found to be lower in RA patients with periodontitis. It is also inversely correlated with the periodontal parameters. Thus, omentin can serve as a significant diagnostic and therapeutic tool in both periodontal and rheumatoid disease.
Purpose The purpose of this study was to determine if older adults residing in long-term care were able to accurately self-report their swallowing status by comparing subjective complaints of ...dysphagia and objective methods of swallowing screening. Method Data were collected from 397 residents of long-term care (M
= 86.8 years ± 7.8; 263 female). Cognitive impairment scores were collected, and each resident was asked (a) if they thought they had a swallowing problem, (b) if they coughed/choked when they ate, and (c) if they coughed/choked when they drank. These responses were compared to results of a swallowing screening tool and mealtime observations of coughing and choking. Results Residents who reported swallowing difficulties (10%, n = 41) were 8 times more likely to fail the swallowing screening (p < .001); however, 80% of residents who failed the swallowing screening did not previously report that swallowing was an issue. There was no significant association between self-reports of coughing and choking at meals and observations. There was no difference in level of cognition between residents who accurately reported swallowing status and those who were inaccurate. Conclusions Residents are largely unable to accurately self-report swallowing difficulties and also have difficulty accurately reporting incidences of coughing and choking. These findings suggest that concerted efforts are required to implement regular, formal swallowing screening protocols in long-term care to objectively identify those at risk.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
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