This work investigates the framework and statistical performance guarantee of the composite neural network, which is composed of a collection of pre-trained and non-instantiated neural network models ...connected as a rooted directed acyclic graph, for solving complicated applications. A pre-trained neural network model is generally well trained, targeted to approximate a specific function. The advantages of adopting a pre-trained model as a component in composing a complicated neural network are two-fold. One is benefiting from the intelligence and diligence of domain experts, and the other is saving effort in data acquisition as well as computing resources and time for model training. Despite a general belief that a composite neural network may perform better than any a single component, the overall performance characteristics are not clear. In this work, we propose the framework of a composite network, and prove that a composite neural network performs better than any of its pre-trained components with a high probability. In the study, we explore a complicated application-PM2.5 prediction-to support the correctness of the proposed composite network theory. In the empirical evaluations of PM2.5 prediction, the constructed composite neural network models perform better than other machine learning models.
A novel photo-triggered self-catalyzed fluoroalkylation/cyclization of quinazolinones containing unactivated alkenes with various fluoroalkyl bromides has been developed. This transformation exhibits ...excellent substrate generality with respect to both the coupling partners. Of note is that this is the first example describing the Csp3–Br bond homolysis of alkyl bromides via a substrate (quinazolinones) induced energy transfer process. Additionally, the mild conditions, tolerance to a wide range of functional groups and operational simplicity make this protocol practical for the synthesis of fluorine-containing ring-fused quinazolinones.
The renal medulla is a key site for the regulation of renal sodium excretion. However, the molecular mechanism remains unclear. Cyclooxygenase 2 (COX2) is specifically expressed in the renal medulla ...and contributes to the maintenance of the electrolyte/water balance in the body. Hypoxia-inducible factors (HIFs) have also been found to be expressed in the renal medulla, probably owing to the hypoxic conditions in the renal medulla. This study was designed to test the effects of HIF activation on renal sodium handling and renal medullary COX2 expression. Our data showed that HIF activation by the prolyl hydroxylase inhibitor (PHI) FG4592 enhanced natriuresis in mice challenged with a high-salt diet. In addition, FG4592 upregulated the expression of COX2 in the renal medulla. An in vitro study further supported the finding that HIF can induce the expression of COX2 and that this induction is mediated through direct binding to the promoter region of the Cox2 gene, facilitating its transcription. In addition, the COX2 inhibitor celecoxib diminished the natriuretic effect of FG4592. Together, these results suggest that HIF activation promotes sodium excretion through upregulation of COX2 in the renal medulla and therefore maintains sodium homeostasis in the body.
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•BOF slag and phosphate tailings were synergistically treated to recover P.•P2O5 was concentrated in a specific mineral phase in the synthetic slag.•Selective leaching was applied for ...separation of the P-rich phase.•Undissolved synthetic slag can be reutilized as a flux in steel plants.•The precipitate extracted from the leachate can be used as a P-Si fertilizer.
To efficiently recover phosphorus from industrial solid wastes, the collaborative processing of P-bearing steelmaking slag and phosphate tailings was proposed. Steelmaking slag and phosphate tailings were remelted to make P enrich in a specific mineral phase and then selective leaching was adopted to separate the P-concentrating mineral phase. The P-concentrating leachate can be used to recover calcium phosphate by chemical precipitation. It shows that the P was mainly concentrated in the dicalcium silicate after remelting of steelmaking slag and phosphate tailings and it could be selectively leached. When the mass ratio of the original BOF slag to phosphate tailings was 7:3, the mixed slag with basicity of 2.3 was obtained. The dissolution efficiency of P from this mixed slag reached 89.2% whereas Fe was barely leached at pH 1. The residue containing 68.6% FetO and 15.6% MgO can be reused in the metallurgical process. When the pH of leachate was adjusted to 7, more than 89.3% of phosphate ions precipitated in the form of calcium phosphate, and the obtained precipitate containing 28.8% CaO, 19.8% P2O5, and 47.2% SiO2, could be a potential P-Si fertilizer. The total recovery ratio of P from mixed slag was approximately 80% and other components could be reused in steel plants, achieving the comprehensive utilization of steelmaking slag and phosphate tailings.
Sirtuin 1 (Sirt1) is a NAD+-dependent deacetylase that exerts many of the pleiotropic effects of oxidative metabolism. Due to local hypoxia and hypertonicity, the renal medulla is subject to extreme ...oxidative stress. Here, we set out to investigate the role of Sirt1 in the kidney. Our initial analysis indicated that it was abundantly expressed in mouse renal medullary interstitial cells in vivo. Knocking down Sirt1 expression in primary mouse renal medullary interstitial cells substantially reduced cellular resistance to oxidative stress, while pharmacologic Sirt1 activation using either resveratrol or SRT2183 improved cell survival in response to oxidative stress. The unilateral ureteral obstruction (UUO) model of kidney injury induced markedly more renal apoptosis and fibrosis in Sirt1+/- mice than in wild-type controls, while pharmacologic Sirt1 activation substantially attenuated apoptosis and fibrosis in wild-type mice. Moreover, Sirt1 deficiency attenuated oxidative stress-induced COX2 expression in cultured mouse renal medullary interstitial cells, and Sirt1+/- mice displayed reduced UUO-induced COX2 expression in vivo. Conversely, Sirt1 activation increased renal medullary interstitial cell COX2 expression both in vitro and in vivo. Furthermore, exogenous PGE2 markedly reduced apoptosis in Sirt1-deficient renal medullary interstitial cells following oxidative stress. Taken together, these results identify Sirt1 as an important protective factor for mouse renal medullary interstitial cells following oxidative stress and suggest that the protective function of Sirt1 is partly attributable to its regulation of COX2 induction. We therefore suggest that Sirt1 provides a potential therapeutic target to minimize renal medullary cell damage following oxidative stress.
Full reaction mechanism of the methanol-to-olefins conversion was proposed in which olefins themselves other than methylbenzenes are the dominating hydrocarbon pool species. The distribution of ...cracking precursors like carbenium ions and alkoxides affects the product selectivity. Display omitted
► Full reaction network of the methanol-to-olefins (MTO) conversion is proposed. ► Reaction mainly involves methylation, isomerization, cracking, hydride transfer, and cyclization. ► Methylbenzenes are not likely to be the hydrocarbon pool species. ► The dynamic distribution of cracking precursors affects the product selectivity.
Full mechanistic understanding of methanol-to-olefins (MTO) conversion is urgently required, not least for the precise control of product selectivity and rational design of zeolite catalysts. Due to its complex nature, the MTO reaction mechanism is still a hot area of dispute. It was traditionally believed that the MTO reaction proceeds through hydrocarbon pool mechanism and methylbenzenes (MBs) are the predominant hydrocarbon pool species. However, by extensive periodic density functional theory (DFT) calculations in HSAPO-34 catalyst, this work indicates that olefins themselves other than MBs are likely to be the dominating hydrocarbon pool species. A full reaction network is established, and the routes to produce olefins, alkanes, and aromatics are formulated. We find that light olefins such as ethene and propene are mainly produced through the scission of cracking precursors (carbenium ions, alkoxides, and higher olefins), and which are formed by the methylation of lighter olefins. The distribution of these cracking precursors as the number of carbon atoms in the pore of catalysts influences the product selectivity from the reaction point of view. A decrease trend in the cracking energy barriers is observed with the carbon atom number of cracking precursors. Hydride transfer between two olefins results in the formation of alkanes and dienes and the latter are likely to be the precursors to form aromatics and subsequently leading to the deactivation of catalysts. This reaction network allows us to rationalize some experimental findings, and more importantly, provides clues on the understanding of selectivity and deactivation.
There is a discrepancy between west and east on the relationship between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). This study aimed to find out the possible reason ...for this and to clarify the association between NAFLD and CKD by analyzing two population-based datasets from the US and China.
Two health examination datasets from China and the US were used. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m
or and/or abnormal albuminuria and/or overt proteinuria. Binary logistic regression was used to examine the association between NAFLD and CKD.
A total of 60,965 participants were analyzed, including 11,844 from the US and 51,229 from China. The prevalence of NAFLD was 27.12% in the Chinese population and 36.08% in the US population (p < 0.001). The proportions of CKD and late stage CKD (stages 3-5) were higher in the US population than the Chinese one. NAFLD was independently associated with an increased risk of CKD in Chinese population, whereas in the US population, the NAFLD was not an independent risk factor of CKD. In subgroup analyses which excluded late stages CKD (stages 3-5), the risks of mild renal function decline became consistent: NAFLD was associated with early stages of CKD but not the late stages of CKD in both populations.
NAFLD increased the risk of early stages of CKD in both Chinese and the US population. The conflicting results reported by previous studies might result from the different proportion of late stages of CKD.
This article introduces some basic theories of space information networking (SIN), which is a novel research field. A SIN is a network that is able to achieve real-time acquisition, transmission, and ...processing of space information. The article first investigates the basic satellite-terrestrial architecture of SINs, and then three key technologies of SINs are presented, specifically more details on the high data rate transmission theory. The DSC is the foundation of high data rate transmission; thus, the core technology of DSC, which is beam/beamforming theory, is discussed in detail. Compared to the traditional spot beam theory, this article proposes a novel VBF concept, which is capable of increasing the channel capacity. Some key technologies are also investigated for VBF; they are channel capacity theoretical analysis, opportunistic beamforming, virtual multi-beamforming, and resource management.
Accurate PM2.5 prediction is part of the fight against air pollution that helps governments to manage environmental policy. Satellite Remote sensing aerosol optical depth (AOD) processed by The ...Multi-Angle Implementation of Atmospheric Correlation (MAIAC) algorithm allows us to observe the transportation of remote pollutants between regions. The paper proposes a composite neural network model, the Remote Transported Pollutants (RTP) model, for such long-range pollutant transportation that predicts more accurate local PM2.5 concentrations given such satellite data. The proposed RTP model integrates several deep learning components and learns from the heterogeneous features of various domains. We also detected remote transportation pollution events (RTPEs) at two reference sites from the AOD data. Extensive experiments using real-world data show that the proposed RTP model outperforms the base model that does not account for RTPEs by 17%-30%, 23%-26% and 18%-22% and state-of-the-art models that account for RTPEs by 12%-22%, 12%-14%, and 10%-11% at +4h to +24h, +28h to +48 hours, and +52h to +72h hours respectively.
•We design a joint and deep learning framework to predict the clinical scores of AD.•We use the group LASSO and correntropy for dimension reduction via feature selection.•We explore the multi-layer ...independently recurrent neural network regression.•We predict the clinical score by learning relationship between MRI and clinical score.
Alzheimer's disease (AD) is a progressive neurodegenerative disease that often grows in middle-aged and elderly people with the gradual loss of cognitive ability. Presently, there is no cure for AD. Furthermore, the current clinical diagnosis of AD is too time-consuming. In this paper, we design a joint and deep learning framework to predict clinical scores of AD. Specifically, the feature selection method combining group LASSO and correntropy is used to reduce dimensions and screen the features of brain regions related to AD. We explore the multi-layer independently recurrent neural network regression to study the internal connection between different brain regions and the time correlation between longitudinal data. The proposed joint deep learning network studies the relationship between the magnetic resonance imaging and clinical score, and predicts the clinical score. The predicted clinical score values allow doctors to perform early diagnosis and timely treatment of patients’ disease condition.
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