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1.
Chemosphere ; 287(Pt 4): 132431, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34606900

RESUMO

Reutilization of the waste by-products from industrial and agricultural activities is crucially important towards attainment of environmental sustainability and the 'circular economy'. In this study, we have developed and evaluated a sustainably-sourced adsorbent from coal fly ash, which was modified by a small amount of lanthanum (La-FA), for the recapture of phosphorous (P) from both synthetic and real natural waters. The prepared La-FA adsorbent possessed typical characteristic diffraction peaks similar to zeolite type Na-P1, and the BET surface area of La-FA was measured to be 10.9 times higher than that of the original FA. Investigation of P adsorption capability indicated that the maximum adsorption (10.8 mg P g-1) was 6.14 times higher than that (1.8 mg P g-1) of the original fly ash material. The ζ potentials measurement and P K-edge X-ray Absorption Near Edge Structure (XANES) spectra demonstrated that P was bonded on La-FA surfaces via an adsorption mechanism. After applying the proposed adsorbent to real lake water with La/P molar ratios in the range from 0.5:1 to 3:1, the La-FA adsorbent showed the highest phosphate removal ability with a La/P molar ratio 1:1, and the P adsorption was similar to that performance with the synthetic solution. Moreover, the La-FA absorbent produced a negligible effect on the concentrations of total dissolved nitrogen (TDN), NH4+-N and NO3--N in water. This study thus provides a potential material for effective P recapture and details of its operation.


Assuntos
Poluentes Químicos da Água , Zeolitas , Adsorção , Carvão Mineral , Cinza de Carvão , Fósforo , Poluentes Químicos da Água/análise
2.
J Clin Neurosci ; 94: 1-7, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34863421

RESUMO

OBJECTIVE: To delineate the outcomes of paediatric patients with myelin oligodendrocyte glycoprotein antibody disease (MOGAD). METHODS: We retrospectively analyzed the clinical characteristics, treatment, and outcomes of 34 paediatric patients with MOGAD from July 2015 to January 2020. RESULTS: The median age at disease onset was 75.5 months (range: 19-170 months). The female-to-male ratio was 1:1.1. The median follow-up duration was 34.5 months (range: 14-63 months). Acute disseminated encephalomyelitis (ADEM) was the most common initial phenotype (52.9%), followed by optic neuritis (ON) (20.6%). Children with ADEM were younger than those with ON (P = 0.045). Twenty-eight (82.4%) and 18 (56.3%) children had abnormal brain and spinal magnetic resonance imaging, respectively, during the first acute attack. MOG-abs titers in children with ON were statistically higher than those in children with ADEM (P = 0.04). Thirty-two children accepted glucocorticoid treatment, while 33 (97%) children demonstrated clinical improvement within 1 week, 21 children (61.8%) achieved clinical recovery within 1 month. Eight children (23.5%) suffered a relapse, the median interval between the initial attack and recurrence was 13 (range: 3-36) months. We detected neurological sequelae in seven (20.6%) children, with visual dysfunction being the most common sequela (85.7%). CONCLUSION: ADEM was the most common phenotype in both monophasic and relapsed paediatric MOGAD, followed by ON. Majority of pediatric MOGAD patients were highly responsive to glucocorticoid. Despite a benign prognosis in most patients, some patients endure neurological sequelae, mainly visual impairment. Patients with initial visual impairment should be carefully evaluated and administered individualized immunotherapy.

3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 1116-1119, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34891483

RESUMO

Traditional biometrics such as face, iris and fingerprint have been applied widely nowadays. Nevertheless, with more and more potential problems being exposed, such as privacy leak and fabricate attack, it is urgent to find new secure biometrics to meet the needs. Identification based on brain signals is a promising option due to its unique advantages of confidentiality, anti-spoofing, continuity and cancelability. Among various types of brain signals, local field potential (LFP) has long term stability, high signal to noise ratio and high spatial resolution, which is suitable for identification. In this paper, we propose a novel biometric which is extracted from LFP signals with a deep neural network. The proposed biometric can be generated in a task-related manner thus is cancelable. Experiments with ten rats demonstrate that, the proposed biometric achieves a high identification accuracy of 94.47%, and the performance is stable over several days.

4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 4969-4973, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34892323

RESUMO

Information transmission security is an important issue in many scenarios such as password input. Traditional approaches such as typing or voice input are prone to peep, leading to a risk of information leakage. Brain computer interface (BCI) can read information directly from the brain, which is confidential inherently, thus it may be an ideal way for secure information input. This paper proposes a novel BCI-based secure input approach with encrypted feedback. The encrypted feedback is specially designed to notify users and confuse peepers at the same time. We give the theoretical guarantee of accuracy and evaluate the system with both simulation and experiments. The results show that our method can transmit messages effectively.

5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 6198-6202, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34892531

RESUMO

Neuroprosthesis refers to implantable medical devices which can replace injured biological functions in the brain. One of the core problems in neuroprosthesis study is to construct a neural signal transformation model from one cortical area to another. Since the brain encodes and transmits information in spike trains, spiking neural network (SNN) can be an ideal choice for neuroprosthesis modeling. This paper proposes a spiking neuron point-process model (SNPM), which receives spike times as input, and is capable of modeling nonlinear interactions between cortical areas. The proposed SNPM can be implemented on neuromorphic chips for low-energy computing, thus has potential for clinical applications. Experiments show that SNPM can accurately reconstruct functional relationships from PMd (dorsal premotor cortex) to M1 (primary motor cortex) areas.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34723807

RESUMO

Spiking neural networks (SNNs) have received significant attention for their biological plausibility. SNNs theoretically have at least the same computational power as traditional artificial neural networks (ANNs). They possess the potential of achieving energy-efficient machine intelligence while keeping comparable performance to ANNs. However, it is still a big challenge to train a very deep SNN. In this brief, we propose an efficient approach to build deep SNNs. Residual network (ResNet) is considered a state-of-the-art and fundamental model among convolutional neural networks (CNNs). We employ the idea of converting a trained ResNet to a network of spiking neurons named spiking ResNet (S-ResNet). We propose a residual conversion model that appropriately scales continuous-valued activations in ANNs to match the firing rates in SNNs and a compensation mechanism to reduce the error caused by discretization. Experimental results demonstrate that our proposed method achieves state-of-the-art performance on CIFAR-10, CIFAR-100, and ImageNet 2012 with low latency. This work is the first time to build an asynchronous SNN deeper than 100 layers, with comparable performance to its original ANN.

7.
J Neurosci Res ; 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34766648

RESUMO

Thalamus and thalamocortical connectivity are crucial for consciousness; however, their microstructural changes in patients with a disorder of consciousness (DOC) have not yet been thoroughly characterized. In the present study, we applied the novel fixel-based analysis to comprehensively investigate the thalamus-related microstructural abnormalities in 10 patients with DOC using 7-T diffusion-weighted imaging data. We found that compared to healthy controls, patients with DOC showed reduced fiber density (FD) and fiber density and cross-section (FDC) in the mediodorsal, anterior, and ventral anterior thalamic nuclei, while fiber-bundle cross-section (FC) was not significantly altered in the thalamus. Impaired thalamocortical connectivity in the DOC cohort was mainly connected to the middle frontal gyrus, anterior cingulate gyrus, fusiform gyrus, and sensorimotor cortices, including the precentral gyrus and postcentral gyrus, with predominant microstructural abnormalities in FD and FDC. Correlation analysis showed that FC of the right mediodorsal thalamus was negatively correlated with the level of consciousness. Our results suggest that microstructural abnormalities of thalamus and thalamocortical connectivity in DOC were mainly attributed to axonal injury. In particular, the microstructural integrity of the thalamus is a vital factor in consciousness generation.

8.
Water Res ; 209: 117887, 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34839067

RESUMO

Driven by winds, the distribution of algae is often noticeably patchy at kilometer scales in shallow lakes. The decomposition of the settled algal biomass may affect nitrogen (N) biogeochemical cycles and thereby N loss in sediments. In this study, we investigated sediment denitrification N-loss patterns along algal migration pathway in Taihu Lake, a shallow and eutrophic lake in China, and found that wind-induced algal migration in the overlying water manipulated the temporal and spatial patterns of denitrification N-loss in sediments. A N loss hotspot in sediments was created in the algae concentrated zone, where N loss was, however, temporarily inhibited during algal bloom seasons and generally exhibited a negative relationship with algal biomass. In the zone where algae have left, sediment N loss rate was relatively low and positively correlated with algal biomass. The decay of algal biomass generated organic carbon and created anoxia, favoring denitrification, while excessive algal biomass could deplete oxygen and inhibit nitrification, causing nitrate limitation for denitrification. Piecewise linear regression analysis indicated that algal biomass of Chl-a > 73.0 µg/L in the overlying water could inhibit denitrification N-loss in sediments. This study adds to our understanding of N biogeochemical cycles in shallow eutrophic lakes.

9.
Artigo em Inglês | MEDLINE | ID: mdl-34665741

RESUMO

Neural coding, including encoding and decoding, is one of the key problems in neuroscience for understanding how the brain uses neural signals to relate sensory perception and motor behaviors with neural systems. However, most of the existed studies only aim at dealing with the continuous signal of neural systems, while lacking a unique feature of biological neurons, termed spike, which is the fundamental information unit for neural computation as well as a building block for brain-machine interface. Aiming at these limitations, we propose a transcoding framework to encode multi-modal sensory information into neural spikes and then reconstruct stimuli from spikes. Sensory information can be compressed into 10% in terms of neural spikes, yet re-extract 100% of information by reconstruction. Our framework can not only feasibly and accurately reconstruct dynamical visual and auditory scenes, but also rebuild the stimulus patterns from functional magnetic resonance imaging (fMRI) brain activities. More importantly, it has a superb ability of noise immunity for various types of artificial noises and background signals. The proposed framework provides efficient ways to perform multimodal feature representation and reconstruction in a high-throughput fashion, with potential usage for efficient neuromorphic computing in a noisy environment.

10.
J Neural Eng ; 18(5)2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34663771

RESUMO

Objective. Brain-machine interfaces (BMIs) provide a direct pathway between the brain and external devices such as computer cursors and prosthetics, which have great potential in motor function restoration. One critical limitation of current BMI systems is the unstable performance, partly due to the variability of neural signals. Studies showed that neural activities exhibit trial-to-trial variability, and the preferred direction of neurons frequently changes under different conditions. Therefore, a fixed decoding function does not work well.Approach. To deal with the problems, we propose a novel kernel regression framework. The nonparametric kernel regression is used to fit diverse decoding functions by finding similar neural patterns to handle neural variations caused by varying tuning functions. Further, the representations of raw neural signals are learned by Siamese networks and constrained by kinematic parameters, which can alleviate neural variations caused by intrinsic noises and task-irrelevant information. The representations are jointly learned with the kernel regression framework in an end-to-end manner so that neural variations can be tackled effectively.Main results. Experiments on two datasets demonstrate that our approach outperforms most existing methods and significantly improves the robustness in challenging situations such as limited samples and missing channels.Significance. The proposed approach demonstrates robust performance with different conditions and provides a new and inspiring perspective toward robust BMI control.


Assuntos
Interfaces Cérebro-Computador , Encéfalo , Neurônios
11.
OMICS ; 25(10): 652-659, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34520261

RESUMO

Type 2 diabetes (T2D) is characterized by pathophysiological alterations in lipid metabolism. One strategy to understand the molecular mechanisms behind these abnormalities is to identify cis-regulatory elements (CREs) located in chromatin-accessible regions of the genome that regulate key genes. In this study we integrated assay for transposase-accessible chromatin followed by sequencing (ATAC-seq) data, widely used to decode chromatin accessibility, with multi-omics data and publicly available CRE databases to identify candidate CREs associated with T2D for further experimental validations. We performed high-sensitive ATAC-seq in nine human liver samples from normal and T2D donors, and identified a set of differentially accessible regions (DARs). We identified seven DARs including a candidate enhancer for the ACOT1 gene that regulates the balance of acyl-CoA and free fatty acids (FFAs) in the cytoplasm. The relevance of ACOT1 regulation in T2D was supported by the analysis of transcriptomics and proteomics data in liver tissue. Long-chain acyl-CoA thioesterases (ACOTs) are a group of enzymes that hydrolyze acyl-CoA esters to FFAs and coenzyme A. ACOTs have been associated with regulation of triglyceride levels, fatty acid oxidation, mitochondrial function, and insulin signaling, linking their regulation to the pathogenesis of T2D. Our strategy integrating chromatin accessibility with DNA binding and other types of omics provides novel insights on the role of genetic regulation in T2D and is extendable to other complex multifactorial diseases.

12.
Front Endocrinol (Lausanne) ; 12: 738138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34531829

RESUMO

Objective: Our goal was to investigate the correlation between papillary thyroid carcinoma (PTC) characteristics on ultrasonography and metastases of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN). There is still no good method for clinicians to judge whether a patient needs LN-prRLN resection before surgery, and we also wanted to establish a new scoring system to determine whether patients with papillary thyroid carcinoma require LN-prRLN resection before surgery. Patients and Methods: There were 482 patients with right or bilateral PTC who underwent thyroid gland resection from December 2015 to December 2017 recruited as study subjects. The relationship between the PTC characteristics on ultrasonography and the metastases of LN-prRLN was analyzed by univariate and logistic regression analyses. Based on the risk factors identified in univariate and logistic regression analysis, a nomogram-based LN-prRLN prediction model was established. Result: LN-prRLN were removed from all patients, of which 79 had LN-prRLN metastasis, with a metastasis rate of 16.39%. Multivariate logistic regression analysis revealed that LN-prRLN metastasis was closely related to sex, age, blood supply, larger tumors (> 1 cm) and capsular invasion. A risk prediction model has been established and fully verified. The calibration curve used to evaluate the nomogram shows that the consistency index was 0.75 ± 0.065. Conclusion: Preoperative clinical data, such as sex, age, abundant blood supply, larger tumor (> 1 cm) and capsular invasion, are positively correlated with LN-prRLN metastasis. Our scoring system can help surgeons non-invasively determine which patients should undergo LN-prRLN resection before surgery. We recommend that LN-prRLN resection should be performed when the score is above 103.1.

13.
Water Res ; 205: 117657, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34547699

RESUMO

The arsenic (As)-bearing eutrophic waters may suffer from the dual conditions of harmful algal blooms and release of As, driven by algal-induced hypoxia/anoxia. Here, we investigate the use of interfacial oxygen (O2) nanobubble technology to combat the hypoxia and control As exposure in simulated mesocosm experiments. It was observed that remediation of algal-induced hypoxia at the sediment-water interfaces (SWI) by application of O2 nanobubbles reduced the level of dissolved As from 23.2 µg L-1 to <10 µg L-1 and stimulated the conversion of As(III) to the less toxic As(V) (65-75%) and methylated As (10-15%) species. More than half of the oxidation and all the methylation of As(III) resulted from the manipulation by O2 nanobubbles of microbes responsible for As(III) oxidation and methylation. Hydroxyl radicals were generated during the oxidation of reductive substances at the SWI in darkness, and should be dominant contributors to As(III) abiotic oxidation. X-ray absorption near-edge structure (XANES) spectroscopic analysis demonstrated that surface sediments changed from being sources to acting as sinks of As, due to the formation of Fe-(hydr)oxide. Overall, this study suggests that interfacial O2 nanobubble technology could be a potential method for remediation of sediment As pollution through the manipulation of O2-related microbial and geochemical reactions.


Assuntos
Arsênio , Poluentes Químicos da Água , Arsênio/análise , Sedimentos Geológicos , Oxirredução , Oxigênio , Tecnologia , Poluentes Químicos da Água/análise
14.
Life Sci Alliance ; 4(7)2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099540

RESUMO

Recent studies suggested that dysregulated YY1 plays a pivotal role in many liver diseases. To obtain a detailed view of genes and pathways regulated by YY1 in the liver, we carried out RNA sequencing in HepG2 cells after YY1 knockdown. A rigid set of 2,081 differentially expressed genes was identified by comparing the YY1-knockdown samples (n = 8) with the control samples (n = 14). YY1 knockdown significantly decreased the expression of several key transcription factors and their coactivators in lipid metabolism. This is illustrated by YY1 regulating PPARA expression through binding to its promoter and enhancer regions. Our study further suggest that down-regulation of the key transcription factors together with YY1 knockdown significantly decreased the cooperation between YY1 and these transcription factors at various regulatory regions, which are important in regulating the expression of genes in hepatic lipid metabolism. This was supported by the finding that the expression of SCD and ELOVL6, encoding key enzymes in lipogenesis, were regulated by the cooperation between YY1 and PPARA/RXRA complex over their promoters.


Assuntos
Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Fator de Transcrição YY1/metabolismo , Sequência de Bases , Elongases de Ácidos Graxos , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/fisiologia , PPAR alfa/genética , Regiões Promotoras Genéticas/genética , Receptor X Retinoide alfa , Estearoil-CoA Dessaturase , Fatores de Transcrição/genética , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/fisiologia
15.
Biochim Biophys Acta Gene Regul Mech ; 1864(8): 194724, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34171462

RESUMO

The stearoyl-CoA desaturase 1 (SCD1) gene at 10q24.31 encodes the rate limiting enzyme SCD1 that catalyzes the biosynthesis of monounsaturated fatty acids (MUFAs) from saturated fatty acids (SFAs). Dysregulated SCD1 activity has been observed in many human diseases including non-alcoholic fatty liver disease (NAFLD), obesity, hypertension, hyperlipidemia, metabolic syndrome and several types of cancer. HNF4A is a central regulator of glucose and lipid metabolism and previous studies suggested that it is deeply involved in regulating the SCD1 activity in the liver. However, the underlying mechanisms on whether and how SCD1 is regulated by HNF4A have not been explored in detail. In this study, we found that HNF4A regulates SCD1 expression by directly binding to the key regulatory regions in the SCD1 locus. Knocking down of HNF4A significantly downregulated the expression of SCD1. Variants rs55710213 and rs56334587 in intron 5 of SCD1 directly reside in a canonical HNF4A binding site. The GG haplotype of rs55710213 and rs56334587 is associated with decreased SCD1 activity by disrupting the binding of HNF4A, which further decreased the enhancer activity and SCD1 expression. In conclusion, our study demonstrated that SCD1 is directly regulated by HNF4A, which may be helpful in the understanding of the altered metabolic pathways in many diseases associated with dysregulated SCD1 or HNF4A or both.


Assuntos
Regulação Enzimológica da Expressão Gênica , Fator 4 Nuclear de Hepatócito/metabolismo , Polimorfismo de Nucleotídeo Único , Estearoil-CoA Dessaturase/genética , Sítios de Ligação , Elementos Facilitadores Genéticos , Haplótipos , Células Hep G2 , Humanos , Desequilíbrio de Ligação , Motivos de Nucleotídeos
16.
Sci Total Environ ; 790: 148010, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34111791

RESUMO

Eutrophication in freshwater environments may be enhanced by the elevation of sulfate in waters, through the release of internal phosphorus (P) from anoxic sediments. However, the influence of increasing but modest sulfate concentrations (less than 3000 µM) on P release under oxic conditions across the sediment-water interface (SWI) in eutrophic freshwater is poorly understood. In this study, the profiles of P, iron (Fe), sulfur (S) and physicochemical parameters were measured in a simulated lacustrine system with varying concentrations of sulfate (970-2600 µM) in overlying water. The results indicated that elevated concentrations of sulfate increased the soluble reactive P in overlying waters under oxic conditions across the SWI. A 100 µM increase of sulfate was found to induce a 0.128 mgm-2d-1 increase of P flux from surface sediments into overlying waters under oxic conditions. Higher sulfate concentrations in the overlying waters increased the concentrations of labile S(-II) in the deep sediments, due to sulfate penetration and subsequent reduction to S(-II). We also found the fluxes of labile Fe (10.34 to 18.33 mgm-2d-1) and P (2.70 to 1.33 mgm-2d-1) from deep to surface sediment were both positive and greater than the corresponding fluxes (Fe, 2.2 to 3.51 and P, 2.6 to 0.39 mgm-2d-1, respectively) from surface sediment to the overlying water, suggesting that reduction of P-bearing Fe(III)(oxyhydr)oxides in deep anoxic sediment acted as a major source of internal P release. In addition, the upward flux of Fe(II) was significantly lower under higher sulfate conditions, indicating that the Fe(II) flux could be mitigated by formation of Fe(II) sulfides in the deep sediment. Under these conditions, less Fe(II) from deep sediments could be re-oxidized and combine with P in the surface, oxic sediment, thereby reducing the retention capacity for P and leading to higher release of internal P to the water column.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Monitoramento Ambiental , Compostos Férricos , Lagos , Fosfatos , Fósforo/análise , Sulfatos , Água , Poluentes Químicos da Água/análise
17.
Gland Surg ; 10(3): 1147-1153, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33842258

RESUMO

Axillary lymph node metastasis is a rare event in thyroid carcinoma. The simultaneous expression of carbohydrate antigens 19-9 (CA 19-9) and 242 (CA 242) in thyroid tumors is also extremely rare. Herein, we report a case of axillary lymph node metastasis with elevated serum CA 19-9 and CA 242 in papillary thyroid carcinoma. In a 47-year-old woman with thyroid carcinoma, masses developed in the neck and axilla over a two-month period, which were surgically treated using total thyroidectomy, with neck and axillary lymph node dissection. Histopathological examination confirmed a diffuse sclerosing variant-papillary thyroid carcinoma, with 52 of 63 axillary lymph node metastases. Notably, serum CA 19-9 and CA 242 levels decreased from the initial values of 1,110 and 50 kU/L, respectively, to normal levels one month postoperatively and have remained stable for two years since. The aggressive biological behavior of diffuse sclerosing variant-papillary thyroid carcinoma and the abnormal anatomical distortion caused by tumors in this case most likely reflect the mechanisms underlying retrograde dissemination in lymphatic tubes. However, the mechanism leading to a simultaneous elevation of CA 19-9 and CA 242 secreted by the diffuse sclerosing variant-papillary thyroid carcinoma has not been elucidated. The patient has survived for two years suggesting that timely surgery can help such patients achieve a better prognosis.

18.
Front Genet ; 12: 618277, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33719335

RESUMO

Autism spectrum disorder (ASD) is a heterogeneous neuropsychiatric disorder with a complex genetic background. Analysis of altered molecular processes in ASD patients requires linear and nonlinear methods that provide interpretable solutions. Interpretable machine learning provides legible models that allow explaining biological mechanisms and support analysis of clinical subgroups. In this work, we investigated several case-control studies of gene expression measurements of ASD individuals. We constructed a rule-based learning model from three independent datasets that we further visualized as a nonlinear gene-gene co-predictive network. To find dissimilarities between ASD subtypes, we scrutinized a topological structure of the network and estimated a centrality distance. Our analysis revealed that autism is the most severe subtype of ASD, while pervasive developmental disorder-not otherwise specified and Asperger syndrome are closely related and milder ASD subtypes. Furthermore, we analyzed the most important ASD-related features that were described in terms of gene co-predictors. Among others, we found a strong co-predictive mechanism between EMC4 and TMEM30A, which may suggest a co-regulation between these genes. The present study demonstrates the potential of applying interpretable machine learning in bioinformatics analyses. Although the proposed methodology was designed for transcriptomics data, it can be applied to other omics disciplines.

19.
Artigo em Inglês | MEDLINE | ID: mdl-33481718

RESUMO

In deep reinforcement learning, off-policy data help reduce on-policy interaction with the environment, and the trust region policy optimization (TRPO) method is efficient to stabilize the policy optimization procedure. In this article, we propose an off-policy TRPO method, off-policy TRPO, which exploits both on- and off-policy data and guarantees the monotonic improvement of policies. A surrogate objective function is developed to use both on- and off-policy data and keep the monotonic improvement of policies. We then optimize this surrogate objective function by approximately solving a constrained optimization problem under arbitrary parameterization and finite samples. We conduct experiments on representative continuous control tasks from OpenAI Gym and MuJoCo. The results show that the proposed off-policy TRPO achieves better performance in the majority of continuous control tasks compared with other trust region policy-based methods using off-policy data.

20.
Bioresour Technol ; 326: 124761, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33503516

RESUMO

High-strength organic wastewater, e.g., potato juice wastewater, exerts high stress on the environment. This study proposes an integrated system for simultaneous high-strength organic wastewater treatment and nutrients upcycling for astaxanthin production by the combination of anaerobic processes and microalgae (Haematococcus pluvialis) cultivation. The potato juice wastewater was pretreated by either acidification or methanation. The effluents of both pretreatments achieved higher biomass yields of H. pluvialis compared to cultivation in standard culture media (control). The high acetate and potassium concentrations of the acidification effluents resulted in significantly higher astaxanthin production (24.5-27.9 mg g-1, 3 days) compared to the control (14.7 mg g-1, 12 days) in a shorter period. The integrated system contributed to a final removal efficiency of 51.3-75.8%, 86.5-98.3%, and 69.4-83.4% for COD, phosphorus, and ammonia, respectively. This study presents a promising two-stage process for simultaneous efficient methane and astaxanthin production, as well as remediation of high-strength organic wastewater.


Assuntos
Clorófitas , Purificação da Água , Xantofilas
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