The effect of corticosteroids on clinical outcomes in patients with influenza pneumonia remains controversial. We aimed to further evaluate the influence of corticosteroids on mortality in adult ...patients with influenza pneumonia by comparing corticosteroid-treated and placebo-treated patients.
The PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials (CENTRAL), and Information Sciences Institute (ISI) Web of Science databases were searched for all controlled studies that compared the effects of corticosteroids and placebo in adult patients with influenza pneumonia. The primary outcome was mortality, and the secondary outcomes were mechanical ventilation (MV) days, length of stay in the intensive care unit (ICU LOS), and the rate of secondary infection.
Ten trials involving 6548 patients were pooled in our final analysis. Significant heterogeneity was found in all outcome measures except for ICU LOS (I
= 38%, P = 0.21). Compared with placebo, corticosteroids were associated with higher mortality (risk ratio RR 1.75, 95% confidence interval CI 1.30 ~ 2.36, Z = 3.71, P = 0.0002), longer ICU LOS (mean difference MD 2.14, 95% CI 1.17 ~ 3.10, Z = 4.35, P < 0.0001), and a higher rate of secondary infection (RR 1.98, 95% CI 1.04 ~ 3.78, Z = 2.08, P = 0.04) but not MV days (MD 0.81, 95% CI - 1.23 ~ 2.84, Z = 0.78, P = 0.44) in patients with influenza pneumonia.
In patients with influenza pneumonia, corticosteroid use is associated with higher mortality.
PROSPERO (ID: CRD42018112384 ).
Prognostics, which usually means the prediction of the field reliability or the Remaining Useful Life (RUL), is the basis of Prognostic and Health Management (PHM). Research in this paper focuses on ...remaining useful life prediction of aircraft engine in the same gradual degradation mode. As the gradual degradation with same failure mechanism has some regularity in macro, there would be certain relation between an arbitrary point of the degradation process and the correspondent RUL. This paper tries to learn this certain relation via neural network and the learned network, which reflects the relation, can be partly perceived as degradation pattern. The main prognostic idea of degradation pattern learning is firstly proposed and illustrated. And then an improved back propagation neural network is designed and analyzed as the implementation technique, in whose loss function an adjacent difference item is added. Next details of implementation via adjacent difference neural network are elaborated. Finally, the proposed approach is validated by two experiments respectively using different aircraft engine degradation datasets. Results of the experiments show a relatively good prediction accuracy, which verifies the correctness, effectiveness and practicability of the idea.
•Degradation pattern learning methodology based on mapping idea is proposed.•Item of adjacent difference for neural network is proposed.•Preprocessing framework for degradation data and a series of indicators are designed.•Prediction of remaining useful life on basic and extensional datasets is promising.
Aspect-based sentiment analysis is a fine-grained sentiment analysis task, which needs to detection the sentiment polarity towards a given aspect. Recently, graph neural models over the dependency ...tree are widely applied for aspect-based sentiment analysis. Most existing works, however, they generally focus on learning the dependency information from contextual words to aspect words based on the dependency tree of the sentence, which lacks the exploitation of contextual affective knowledge with regard to the specific aspect. In this paper, we propose a graph convolutional network based on SenticNet to leverage the affective dependencies of the sentence according to the specific aspect, called Sentic GCN. To be specific, we explore a novel solution to construct the graph neural networks via integrating the affective knowledge from SenticNet to enhance the dependency graphs of sentences. Based on it, both the dependencies of contextual words and aspect words and the affective information between opinion words and the aspect are considered by the novel affective enhanced graph model. Experimental results on multiple public benchmark datasets illustrate that our proposed model can beat state-of-the-art methods.
Carbon dots (CDs) present an enticing prospect for a variety of optical applications relying on their high photoluminescence (PL) quantum yield (QY). Herein, the synthesis, optical properties, ...structural characterizations, density‐functional theory (DFT) calculations, and potential applications of yellow‐emissive CDs (Y‐CDs) with ultra‐high PL QY are reported. Solvothermal treatment of citric acid and urea in toluene, followed by column chromatography, produces Y‐CDs exhibiting excitation‐independent PL emission at 553 nm with a high solution PL QY of 92%. A variety of optical and structural characterizations and DFT theoretical calculations are implemented to confirm the general structure and fluorescence origin of Y‐CDs, conjugated sp2‐carbon domains (fused rings) with edge groups. Significantly, transparent Y‐CDs/acrylic resin films with strong solid‐state emissions are fabricated. The Y‐CD films exhibit a high fluorescence with PL QY of 98%, good PL stability (no PL variation under continuous irradiation for 180 h), and large Stokes shift (129 nm). The potential applications of Y‐CDs for luminescent solar concentrators as well as yellow phosphors for lighting are also demonstrated. These findings thus promote the development of high‐performance CDs and their optoelectronic applications.
The synthesis of yellow‐emissive CDs (Y‐CDs) with ultra‐high photoluminescence quantum yield (QY) over 90% in both solution and solid states is demonstrated. Characterizations and density‐functional theory calculations are performed for understanding of the structure and fluorescence formation of Y‐CDs, conjugated sp2‐carbon domains with edge groups. Y‐CDs are potentially useful for luminescent solar concentrators and as yellow phosphors in optoelectronic applications.
Membrane technology is one of the most promising technologies for separation and purification that is routinely and commercially employed in aqueous solutions. In comparison, its applications in ...organic solvents are severely underdeveloped mainly due to the poor stability of traditional polymer membranes in organic solvents. The emerging materials such as crosslinked polymers, covalent organic frameworks, metal–organic frameworks, conjugated microporous polymers, carbon molecular sieves, and graphene provide the solutions to address this problem. The membranes constructed with these novel materials show outstanding separation performance in regard to both high selectivity and solvent permeability, greatly pushing forward utilization of membrane technology in organic media. Here, an overview of the most important organic mixtures that need to be separated, the major separation processes adopted nowadays in organic solvents, and the recent progress in new developed membranes is provided.
Leaning lessons from seawater desalination and water purification, great efforts are being devoted to extend membrane separation from aqueous solutions to the organic phase. The different separation processes and new developed materials, which promote the application of membrane separation in organic liquids, are reviewed.
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•The output data and potential of industrial solid wastes for CO2 mineralization are analyzed.•The limitation reasons of CO2 mineralization for industrial applications are found.•The ...huge energy and cost consumption is the biggest block for its progress.•The approaches for reducing energy and cost consumption are reviewed.
CO2 mineral carbonation is a promising strategy to abate global warming. However, its industrial applications were still limited. This paper reviews the current developments of mineral carbonation technologies by using industrial solid wastes as feedstocks, aiming at searching the reasons of its limitation. Firstly, the pathways and principles for CO2 mineral carbonation are briefly introduced. Then, the carbonation potential and processes of the most representative and available industrial solid wastes are summarized and compared. Iron and steel slags exhibit great potential due to their high alkali content and reactivity. Based on the preliminary economic analysis, the reasons for the limitation of current scale-up applications of CO2 mineral carbonation are the concerns of energy and cost consumption. The process parameter optimization and equipment design for scale-up applications need to be extensively investigated. Meanwhile, the recovery of high-value products during the carbonation process improves the economy and make the process more promising for industrial applications. The feasibility for recovering various value-added byproducts such as precipitated calcium carbonate (PCC) and zeolites was reported and discussed in this paper. Lastly, two research directions, i.e. the evaluation of CO2 net emission reduction by life cycle assessment technique and developments of new energy-saving approaches, are suggested.
Nano‐/micro‐reactors have emerged as a powerful platform for chemical synthesis. Here, we develop fiber‐spinning chemistry (FSC) based on a microfluidic blow spinning (MBS) technique, allowing the ...availability of nanoreactors for chemical synthesis with scale‐up capacities. Proof‐of‐concept experiments focus on the utilization of MBS‐derived fibrous nanoreactors for large‐scale production of ligand‐free perovskite quantum dots (PQDs) in one step. Typically, methylammonium lead halide (MAPbX3, X=Cl, Br, and I) PQDs in situ synthesized at large scale inside polyacrylonitrile (PAN) nanofiber films (size 120 cm ×30 cm per hour), exhibit high photoluminescence (PL) quantum yield (QY) of 71 %, tunable emissive peaks (448–600 nm), and superb PL stability. The PQDs/polymer nanofiber films are potentially useful for CO2 conversion, wide‐color‐gamut displays and light‐emitting diode (LED) devices. These findings may guide the development of nano‐/micro‐reactor technology for scale‐up production of nanomaterials with various potential applications.
Fiber‐spinning chemistry based on a microfluidic blow spinning (MBS) technique is developed to construct fibrous nanoreactors allowing mass production of ligand‐free perovskite quantum dots (PQDs). The resultant PQDs/polymer nanofiber films possess high fluorescence stability under extreme conditions like light irradiation, heating and water dipping, which show potential applications in photocatalytic CO2 reduction and optoelectronic devices.
•Effective parameters on the performance of ground heat exchangers were surveyed.•MPCS and nanofluid acted as working fluid additives.•The backfill material and groundwater have the greatest impact ...on GHE.•Turbulence promoters such as twisted tape inserted the ground tube were described.•The composite system is an effective method to enhance the performance of GSHP.
Ground heat exchanger is a significant part of the ground source heat pumps system with environment-friendly and energy-saving. The coefficient of performance for the ground source heat pump systems is closely associated with the performance of the ground heat exchanger. Some important research development about the ground heat exchanger has been addressed over the last decades. This paper aims to overview the previous research on improving the thermal and flow performance of the ground heat exchanger. Various and special ground heat exchanger parameters factors: working fluid (gas, antifreeze solution, microencapsulated phase change slurry and nanofluid), turbulence promoter, ground tube (material, structure parameters and optimization tube), backfill materials (conventional type, controlled low strength material and phase change material), soil field (convention type, frozen soil and groundwater) and other factors (operation mode and composite systems).
This paper is divided into six parts. The working fluid, the thermal conductivity of the backfill material and groundwater have the greatest impact on increasing the performance compared to other parameters. The composite system is an effective method to enhance the performance of the ground source heat pump systems.
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Synchrotron radiation (SR) provides highly brilliant light with tunable wavelength from hard X-ray to far infrared, on which scattering, spectroscopy and imaging techniques with high time and spatial ...resolutions have been developed for
in situ
study on biological system and materials like polymer. With examples on flow-induced crystallization of polymer, deformation of nanoparticle filler network in rubber composite and necking propagation in tensile stretch, current work attempts to demonstrate the advantages of
in situ
synchrotron radiation X-ray scattering, X-ray nano-CT and infrared imaging in the study of deformation-induced multi-scale structural evolutions of polymers. With time resolution up to sub-ms, synchrotron radiation is expected to play a great role in understanding non-equilibrium polymer physics under processing and service conditions, while high-throughput characterization platform based on synchrotron radiation opens the possibility to establish polymer Materials Genome database in processing parameter space within reasonable time, which can serve as the roadmap for industrial polymer processing and accelerate material innovation.
The number of hospitalized young coronavirus disease 2019 (COVID-19) patients has increased significantly. However, specific data about COVID-19 patients under 65 years old who are admitted to the ...hospital are scarce.
The COVID-19 patients under 65 years old who were admitted to the hospital in Sichuan Province, Renmin Hospital of Wuhan University, and Wuhan Red Cross Hospital were included in this study. Demographic information, laboratory data and clinical treatment courses were extracted from electronic medical records. Risk factors associated with oxygen therapy were explored.
Eight hundred thirty-three COVID-19 patients under 65 years old were included. Of the included patients, 29.4% had one or more comorbidities. Oxygen therapy was required in 63.1% of these patients, and the mortality was 2.9% among the oxygen therapy patients. Fever (odds ratio OR 2.072, 95% confidence interval CI 1.312-3.271, p = 0.002), dyspnea (OR 2.522, 95% CI 1.213-5.243, p = 0.013), chest distress (OR 2.278, 95% CI 1.160-4.473, p = 0.017), elevated respiratory rate (OR 1.114, 95% CI 1.010-1.228, p = 0.031), and decreased albumin (OR 0.932, 95% CI 0.880-0.987, p = 0.016) and globulin levels (OR 0.929, 95% 0.881-0.980, p = 0.007) were independent factors related to oxygen therapy.
Oxygen therapy is highly required in COVID-19 patients under 65 years old who are admitted to the hospital, but the success rate is high. Respiratory failure-related symptoms, elevated respiratory rate, low albumin and globulin levels, and fever at admission are independent risk factors related to the requirement of oxygen.
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