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1.
Ecotoxicol Environ Saf ; 208: 111605, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396125

RESUMO

This is a novel study about responses of leaf photosynthetic traits and plant mercury (Hg) accumulation of rice grown in Hg polluted soils to elevated CO2 (ECO2). The aim of this study was to provide basic information on the acclimation capacity of photosynthesis and Hg accumulation in rice grown in Hg polluted soil under ECO2 at day, night, and full day. For this purpose, we analyzed leaf photosynthetic traits of rice at flowering and grain filling. In addition, chlorophyll content, soluble sugar and Malondialdehyde (MDA) of rice leaves were measured at flowering. Seed yield, ear number, grain number per ear, 1000-grain weight, total mercury (THg) and methylmercury (MeHg) contents were determined after harvest. Our results showed that Hg polluted soil and ECO2 had no significant effect on leaf chlorophyll content and leaf mass per area (LMA) in rice. The contents of soluble sugar and MDA in leaves increased significantly under ECO2. Mercury polluted soil treatment significantly reduced the light saturated CO2 assimilation rate (Asat) of rice leaves only at flowering, but not at grain filling. Night ECO2 greatly improved rice leaf water use efficiency (WUE). ECO2 greatly increased seed yield and ear number. In addition, ECO2 did not affect THg accumulation in rice organs, but ECO2 and Hg treatment had a significant interaction on MeHg in seeds, husks and roots.

2.
Future Oncol ; 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33397129

RESUMO

Aim: Desmoid tumor (DT) is a rare, locally aggressive benign neoplasm with a high recurrence rate. The majority of sporadic DTs are associated with mutations in CTNNB1, but whether CTNNB1 mutations are associated with the risk of DT recurrence remains unclear. The goal of this meta-analysis was to evaluate the association between CTNNB1 mutation and recurrence in surgically treated DT patients. Methods: PubMed, Embase and Cochrane library were systematically searched. The outcome of interest was the risk of recurrence. The number of patients with CTNNB1 mutation and the number of recurrences they developed were recorded and compared. The quality of these studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Odds ratios and variances were calculated and pooled. Results: A total of eight studies were identified including 637 patients. S45F-mutated DTs were more likely to recur compared with wild type, T41A and other mutated DTs. However, there were no statistically significant differences in the rate of recurrence between wild type and T41A mutation or other mutation. Conclusions: Among CTNNB1 mutations, the mutation S45F is a high-risk factor for recurrence of DT and may be a predictive marker for the recurrence of sporadic DT.

3.
Org Lett ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33417467

RESUMO

We provide an account of synthetic strategies aimed at the efficient preparation of 4-amino-4-methyltetrahydro-2H-thiopyran 1,1-dioxide (3), an important cyclic sulfone building block for medicinal chemistry. A practical and scalable protocol has been developed that readily gives access to the title compound from commercially available and inexpensive starting materials. In addition, this novel approach has enabled the synthesis of various related 4,4-disubstituted cyclic sulfone derivatives that serve as valuable structural motifs for drug discovery.

4.
Nature ; 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33408412

RESUMO

The intensive application of inorganic nitrogen underlies marked increases in crop production, but imposes detrimental effects on ecosystems1,2: it is therefore crucial for future sustainable agriculture to improve the nitrogen-use efficiency of crop plants. Here we report the genetic basis of nitrogen-use efficiency associated with adaptation to local soils in rice (Oryza sativa L.). Using a panel of diverse rice germplasm collected from different ecogeographical regions, we performed a genome-wide association study on the tillering response to nitrogen-the trait that is most closely correlated with nitrogen-use efficiency in rice-and identified OsTCP19 as a modulator of this tillering response through its transcriptional response to nitrogen and its targeting to the tiller-promoting gene DWARF AND LOW-TILLERING (DLT)3,4. A 29-bp insertion and/or deletion in the OsTCP19 promoter confers a differential transcriptional response and variation in the tillering response to nitrogen among rice varieties. The allele of OsTCP19 associated with a high tillering response to nitrogen is prevalent in wild rice populations, but has largely been lost in modern cultivars: this loss correlates with increased local soil nitrogen content, which suggests that it might have contributed to geographical adaptation in rice. Introgression of the allele associated with a high tillering response into modern rice cultivars boosts grain yield and nitrogen-use efficiency under low or moderate levels of nitrogen, which demonstrates substantial potential for rice breeding and the amelioration of negative environment effects by reducing the application of nitrogen to crops.

5.
Artigo em Inglês | MEDLINE | ID: mdl-32512131

RESUMO

Autism spectrum disorder (ASD) is accompanied with widespread impairment in social-emotional functioning. Classification of ASD using sensitive morphological features derived from structural magnetic resonance imaging (MRI) of the brain may help us to better understand ASD-related mechanisms and improve related automatic diagnosis. Previous studies using T1 MRI scans in large heterogeneous ABIDE dataset with typical development (TD) controls reported poor classification accuracies (around 60%). This may because they only considered surface-based morphometry (SBM) as scalar estimates (such as cortical thickness and surface area) and ignored the neighboring intrinsic geometry information among features. In recent years, the shape-related SBM achieves great success in discovering the disease burden and progression of other brain diseases. However, when focusing on local geometry information, its high dimensionality requires careful treatment in its application to machine learning. To address the above challenges, we propose a novel pipeline for ASD classification, which mainly includes the generation of surface-based features, patch-based surface sparse coding and dictionary learning, Max-pooling and ensemble classifiers based on adaptive optimizers. The proposed pipeline may leverage the sensitivity of brain surface morphometry statistics and the efficiency of sparse coding and Max-pooling. By introducing only the surface features of bilateral hippocampus that derived from 364 male subjects with ASD and 381 age-matched TD males, this pipeline outperformed five recent MRI-based ASD classification studies with >80% accuracy in discriminating individuals with ASD from TD controls. Our results suggest shape-related SBM features may further boost the classification performance of MRI between ASD and TD.

6.
J Magn Reson Imaging ; 53(1): 242-250, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32864825

RESUMO

BACKGROUND: Preoperative differentiation of primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM) is important to guide neurosurgical decision-making. PURPOSE: To validate the generalization ability of radiomics models based on multiparametric-MRI (MP-MRI) for differentiating PCNSL from GBM. STUDY TYPE: Retrospective. POPULATION: In all, 240 patients with GBM (n = 129) or PCNSL (n = 111). FIELD STRENGTH/SEQUENCE: 3.0T scanners (two vendors). Sequences: fluid-attenuation inversion recovery, diffusion-weighted imaging (DWI), and contrast-enhanced T1 -weighted imaging (CE-T1 WI). Apparent diffusion coefficients (ADCs) were derived from DWI. ASSESSMENT: Cross-vendor and mixed-vendor validation were conducted. In cross-vendor validation, the training set was 149 patients' data from vendor 1, and test set was 91 patients' data from vendor 2. In mixed-vendor validation, a training set was 80% of data from both vendors, and the test set remained at 20% of data. Single and multisequence radiomics models were built. The diagnoses by radiologists with 5, 10, and 20 years' experience were obtained. The integrated models were built combining the diagnoses by the best-performing radiomics model and each radiologist. Model performance was validated in the test set using area under the ROC curve (AUC). Histological results were used as the reference standard. STATISTICAL TESTS: DeLong test: differences between AUCs. U-test: differences of numerical variables. Fisher's exact test: differences of categorical variables. RESULTS: In cross-vendor and mixed-vendor validation, the combination of CE-T1 WI and ADC produced the best-performing radiomics model, with AUC of 0.943 vs. 0.935, P = 0.854. The integrated models had higher AUCs than radiologists, with 5 (0.975 vs. 0.891, P = 0.002 and 0.995 vs. 0.885, P = 0.007), 10 (0.975 vs. 0.913, P = 0.029 and 0.995 vs. 0.900, P = 0.030), and 20 (0.975 vs. 0.945, P = 0.179 and 0.995 vs. 0.923, P = 0.046) years' experiences. DATA CONCLUSION: Radiomics for differentiating PCNSL from GBM was generalizable. The model combining MP-MRI and radiologists' diagnoses had superior performance compared to the radiologists alone. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 2.

7.
Waste Manag ; 120: 59-67, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33285374

RESUMO

Heavy metal pollutants generated from municipal solid waste (MSW) incineration are mainly concentrated in the fly ash, among which lead species have received considerable attention due to their high content and biotoxicity. CaO is an active component in fly ash to adsorb heavy metal species. In this study, based on density functional theory (DFT) calculations, the migration and transformation mechanisms of lead species over the CaO (100) surface were investigated by calculating the adsorption configurations, energies, and electronic structures, etc. The results indicate that the adsorption of lead species over the CaO (100) surface is dominated by chemisorption, and PbCl2 molecule exhibits a stronger affinity to the CaO surface than Pb0. The dissociation of HCl molecule on the CaO (100) surface facilitates the adsorption and chemical reactivity of lead species. The chlorination of Pb0 to PbCl2 is a two-stage route. In the first stage, two HCl molecules are exothermically adsorbed on the surface without an energy barrier, and Pb0 is directly bonded to the active Cl atom, which is controlled by the Eley-Rideal mechanism. In the second stage, PbCl intermediate bonds with another Cl atom over the surface to form the PbCl2 molecule, following the Langmuir-Hinshelwood mechanism, which is also the rate-determining step. Compared with the homogeneous chlorination, CaO catalyzes the heterogeneous process to greatly reduce the oxidation energy barrier and promotes the formation of PbCl2. Consequently, CaO is able to accelerate the lead enrichment in fly ash, which is favorable for lead species purification.


Assuntos
Metais Pesados , Eliminação de Resíduos , Carbono , Cinza de Carvão , Incineração , Chumbo , Metais Pesados/análise , Material Particulado , Resíduos Sólidos/análise
8.
Appl Radiat Isot ; 168: 109488, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33239195

RESUMO

In our previous research, a new detection method was proposed to measure Hg and Pb simultaneously by combining Prompt Gamma-ray Neutron Activation Analysis (PGNAA) and X-ray Fluorescence (XRF) and proved by the Monte Carlo N-Particle (MCNP) simulation code. For further experimental verification, a combined measurement experimental facility, comprising an 241Am-Be neutron source, SAINT-GOBAIN Bismuth Germanate (BGO) as the γ-ray detector, and an NaI detector with 25 µm Be window as the X-ray detector, was presented. Specifically, the characteristic X-ray fluorescence of the Hg directly induced in this experimental facility was utilized to improve the limits of detection (LOD) of Hg instead of traditional excitation sources. The simulation and experiment results indicated that LOD for Hg by the combined measurement instrument was 19.4 mg kg-1. The empirical formula of the calibration curve in this method was given based on the aforementioned calculations.

9.
J Psychiatr Res ; 133: 197-204, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33360426

RESUMO

Major Depressive Disorder (MDD) is increasingly recognized as a common brain disorder with aberrant brain networks. Alterations in dynamic functional brain networks have been widely reported in MDD. However, previous studies mainly focused on detecting non-overlapping sub-networks/communities, neglecting the possibility that one brain region may belong to multiple sub-networks/communities. In the present work, we utilized tensor decomposition method to detect overlapping communities and study the dynamism of overlapping sub-networks through 58 patients with MDD and 63 age- and sex-matched healthy controls (HC). The strength vectors of communities were calculated and two-sample t-test was performed to investigate the statistical significance of the differences in dynamism of MDD and HC groups. We found that communities detected in two groups were pairwise region-matching but overlapped brain regions were almost totally different. We considered two region-matching communities in the two groups as a sub-network. Compared to HCs, MDD patients showed significantly decreased dynamism in five sub-networks which could be functionally mapped to Visual Network (VN), Default Mode Network (DMN), Cognitive Control Network (CCN), Bilateral Limbic Network (BLN) and Auditory Network (AN). The results showed that MDD might only have a marginal effect on the holistic detection of communities and the changes of overlapped brain regions in MDD patients might be put down to the alteration of hubs. Further statistical analysis on nine sub-networks showed decreased dynamism of five sub-networks in MDD patients, which might help us achieve a better understanding of mechanism in MDD.

10.
J Environ Sci (China) ; 99: 168-174, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183694

RESUMO

The difficulty in achieving high removal efficiency for contaminants in textile wastewater over a wide range of pH impedes the progress of its treatment technique greatly. Herein, a facile and sustainable strategy was adopted for constructing magnetic ordered mesoporous polymers (M-OMPs) without the assistance of organic solvent and catalyst. The prepared M-OMPs were endowed with high special surface area and good superparamagnetism simultaneously, and exhibited high removal efficiency (>99%) for Methylene Blue (MB) within a short time (10 min) at a concentration of 50 mg/L. What's more, high removal efficiency was achieved over a wide range of pH 2-12 and the adsorption capacity for MB on M-OMPs was substantially retained even after 5 adsorption-desorption cycles, further demonstrating the application potential of M-OMPs in the decontamination of textile wastewater.


Assuntos
Azul de Metileno , Polímeros , Adsorção , Fenômenos Magnéticos , Águas Residuárias
11.
Carbohydr Polym ; 251: 117041, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142599

RESUMO

Oudemansiella radicata is a commercialized and nutrient-rich mushroom farmed in China. Polysaccharides (ORP) found in this mushroom possess strong biological properties. In this study, the digestibility and fermentation of ORP and its effects on gut microbiota composition were examined in a simulated digestion and fermentation system in vitro. Results showed that the molecular weight of ORP decreased after simulated digestion. However, no free monosaccharide was detected, indicating that ORP was indigestible. Besides, the overall structure of ORP was not damaged after digestion. When ORP was degraded and utilized by gut microbiota during the fermentation process, several short-chain fatty acids were formed, acetic acid, propionic acid and n-butyric acid were the main products. Notably, ORP could significantly modulate the composition, via increasing the relative abundances of Bacteroides and Parabacteroides. These results suggest that ORP can be used as a functional food to improve health and prevent diseases by promoting gut health.

12.
J Colloid Interface Sci ; 581(Pt A): 66-75, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768735

RESUMO

Controlling the morphology and structure of nanomaterials is of great importance for enhancing the electrochemical properties. In the paper, Mn3O4-Fe3O4@C hybrids with different architectures were synthesized by incubation of electrospun FeOx-containing carbon fiber (Fe-CNF) in KMnO4 solution followed by annealing. The presence of FeOx on the CNF plays a vital role in determining the morphology and structure of the final hybrids, and the Mn3O4-Fe3O4@C hybrids with half-tube, tube and oolite-filled fibers are formed conveniently by tuning Fe content in the carbon fiber precursor. The good conductivity of fiber and various redox states of Mn and Fe afford the facile charge transfer and excellent reversible redox properties, thus enhancing the capacitor performance. The oolite-filled Mn3O4-Fe3O4@C with tubular structure exhibited a high specific capacitance of 178 F g-1 at a discharge rate of 1 A g-1. This capacitor electrode has an excellent cyclic stability with 95% capacitance retention after 1000 cycles at 3 A g-1. This work provides a very simple strategy to tune the unique nanostructures of metal oxide on Fe-CNF for high-performance supercapacitor application in the future.

13.
Trends Plant Sci ; 26(2): 104-107, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33257260

RESUMO

Recent studies indicate that a multitude of microbial processes are involved in nitric oxide production and consumptions in the pedosphere. Due to its dual function as a toxic metabolite and signaling compound, we speculate that this pedospheric nitric oxide of microbial origin can significantly interact with mycorrhizal symbioses and symbiotic nitrogen fixation of legumes.

14.
J Magn Reson Imaging ; 53(2): 427-436, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32869426

RESUMO

BACKGROUND: Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is a rare maternally inherited genetic disease; however, little is known about its underlying brain basis. Furthermore, the dynamic functional connectivity (dFC) of brain networks in MELAS has not been explored. PURPOSE: To investigate the abnormalities of dFC in patients with MELAS at the acute and chronic stages, and to determine the possible relations between dynamic connectivity alterations and volumes of stroke-like lesions (SLLs). STUDY TYPE: Prospective. SUBJECTS: Twenty-two MELAS patients at the acute stage, 23 MELAS patients at the chronic stage, and 22 healthy controls. FIELD STRENGTH/SEQUENCE: Single-shot gradient-recalled echo planar imaging (EPI) sequence at 3T. ASSESSMENT: Dynamic FC states were estimated using the sliding window approach and k-means clustering analyses. Combined with graph theory, the topological properties of the dFC network were also accessed. STATISTICAL TESTS: Permutation test, Pearson correlation coefficient, and false discovery rate correction. RESULTS: We identified four dFC states and found that MELAS patients (especially at the acute stage) spent more time in a state with weaker connectivity (state 1) and less time in states with stronger connectivity. In addition, volumes of acute SLLs were positively correlated with mean dwell time in state 1 (r = 0.539, P < 0.05) and negatively correlated with the number of transitions (r = -0.520, P < 0.05). Furthermore, MELAS patients at the acute stage exhibited significantly increased global efficiency (P < 0.01) and decreased local efficiency (P < 0.001) compared to the controls and the patients at the chronic stage. Patients at the chronic stage only showed significantly (P < 0.001) decreased local efficiency compared to the controls. DATA CONCLUSION: Our findings suggest similar and distinct dFC alterations in MELAS patents at the acute and chronic stages, providing novel insights for understanding the neuropathological mechanisms of MELAS. Level of Evidence 2 Technical Efficacy Stage Stage 2 J. MAGN. RESON. IMAGING 2021;53:427-436.

15.
Front Immunol ; 11: 585168, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33262764

RESUMO

Healthy immune aging is in part determined by how well the sizes of naïve T cell compartments are being maintained with advancing age. Throughout adult life, replenishment largely derives from homeostatic proliferation of existing naïve and memory T cell populations. However, while the subpopulation composition of CD4 T cells is relatively stable, the CD8 T cell compartment undergoes more drastic changes with loss of naïve CD8 T cells and accumulation of effector T cells, suggesting that CD4 T cells are more resilient to resist age-associated changes. To determine the epigenetic basis for these differences in behaviors, we compared chromatin accessibility maps of CD4 and CD8 T cell subsets from young and old individuals and related the results to the expressed transcriptome. The dominant age-associated signatures resembled hallmarks of differentiation, which were more pronounced for CD8 naïve and memory than the corresponding CD4 T cell subsets, indicating that CD8 T cells are less able to keep cellular quiescence upon homeostatic proliferation. In parallel, CD8 T cells from old adults, irrespective of their differentiation state, displayed greater reduced accessibility to genes of basic cell biological function, including genes encoding ribosomal proteins. One possible mechanism is the reduced expression of the transcription factors YY1 and NRF1. Our data suggest that chromatin accessibility signatures can be identified that distinguish CD4 and CD8 T cells from old adults and that may confer the higher resilience of CD4 T cells to aging.

16.
Sci Total Environ ; 749: 142049, 2020 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-33370921

RESUMO

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and its primary metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) are frequently detected in aquatic environments. However, information regarding the biotoxicity of these compounds to bivalves is limited. We explored the multilevel physiological responses of Corbicula fluminea to TDCIPP and BDCIPP. The results indicated that TDCIPP/BDCIPP bioaccumulation in bivalves was positively correlated with their hydrophobicity. Furthermore, the higher body burden of TDCIPP in digestive glands led to significantly higher levels of ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), and P-glycoprotein (p < 0.05). Owing to different molecular structures of inducers, upregulations of cyp4, gstm1, and abcb1 mRNA exhibited different sensitivities to TDCIPP and BDCIPP. Although Phase-I and Phase-II biotransformation and the multixenobiotic resistance (MXR) system were activated to protect bivalves from TDCIPP or BDCIPP, digestive glands produced large amounts of reactive oxygen species (ROS). Moreover, oxidative stress, the percentage of apoptotic cells in digestive glands, and inhibition of siphoning behaviour in TDCIPP treatments were higher than those in BDCIPP treatments (p < 0.05), indicating that TDCIPP was more toxic to bivalves than BDCIPP. Lower bioaccumulation and rapid metabolism of BDCIPP in vivo may contribute to alleviating its toxicity. This research establishes a foundation for further understanding the differences between the toxic mechanisms of TDCIPP and its metabolites.


Assuntos
Corbicula , Retardadores de Chama , Animais , Organofosfatos , Compostos Organofosforados , Estresse Oxidativo , Fosfatos
17.
Am J Alzheimers Dis Other Demen ; 35: 1533317520971414, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33258666

RESUMO

Apolipoprotein E 4 Allele (APOE 4) is an important factors in Mild cognitive impairment (MCI) and Alzheimer's disease(AD). It plays a primary role in abnormal modification of aggregated Tau protein-paired helical filaments Tau (PHF-Tau). In this study, 143 subjects with PHF-Tau PET were divided into 2 groups (APOE 4 carriers and noncarriers). The measurements of the PHF-Tau network properties and resilient were calculated for 2 group networks respectively. APOE 4 carriers group showed significant differences in all the network properties in the results. We also found significant differences of betweenness centrality in some brain regions for APOE 4 carriers. Moreover, the APOE 4 carriers showed less resilient to targeted or random node failure. Our results indicated that the effects of APOE 4 may lead to abnormalities of PHF-Tau protein network. These findings may be particularly helpful in uncovering the pathophysiology underlying the cognitive dysfunction in MCI patients.

18.
Nanotoxicology ; : 1-14, 2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33370537

RESUMO

The increasing emergence of nano-cosmetics in the marketplace provokes safety concerns with respect to percutaneous permeation and toxicity of nanomaterials inside the human body. In this study, in vivo percutaneous permeation and dermal safety of cosmetic cream containing Au nanosheets and extracted Au nanosheets from cosmetic creams are investigated with guinea pigs. Quantitative percutaneous permeation data suggests that Au nanosheets in cosmetic creams permeate into the skin epidermis, dermis, and subcutaneous layer after 10 d cutaneous exposure, but cannot enter the systemic circulation. However, more Au nanosheets are accumulated in the skin and the permeation of Au nanosheets increased after embedded into the cream matrix. Synchrotron radiation X-ray fluorescence (SRXRF) imaging reveals that Au nanosheets in cosmetics penetrate mainly through hair follicles in a time-dependent manner. Cosmetic creams rather than extracted Au nanosheets decrease the cell viability of keratinocytes and slightly induce apoptosis/necrosis of keratinocytes and skin dermal fibroblasts. Intriguingly, the growth of hair is inhibited by the cosmetic cream and the extracted Au nanosheets revealed by HE staining and immunohistochemistry (IHC) assay. Altogether this study provides insights into the comprehensive understanding of percutaneous permeation and dermal safety of cosmetic creams containing Au nanosheets. This work provides reliable methods to study the skin permeation, biodistribution, and dermal safety of nano-cosmetics and reminds the community of the crucial need to combine the assays at molecular, cellular, and organ levels in nanotoxicology research.

19.
Food Res Int ; 138(Pt B): 109819, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33288191

RESUMO

Macamides, the major bioactive compounds of Lepidium meyenii (Walp.) or Maca, are a unique class of non-polar, long chain fatty acid N-benzylamides with fertility-enhancing, neuroprotective, neuro-modulatory, anti-fatigue and anti-osteoporosis effects. However, the relationship between the structures and pharmacological effects of macamides have not been established so far. In addition, little is known regarding their biosynthetic pathways and the mechanisms underlying the biological activities. In this review, we have summarized the methods currently used for the extraction, purification and synthesis of macamides. Their pharmacological effects, clinical prospects and biomedical applications have also been discussed. Current data strongly suggest that macamides are a promising bio-active agent, and further studies are warranted to elucidate their mechanisms of action.

20.
Artigo em Inglês | MEDLINE | ID: mdl-33338023

RESUMO

Depression is a mental disorder with emotional and cognitive dysfunction. The main clinical characteristic of depression is significant and persistent low mood. As reported, depression is a leading cause of disability worldwide. Moreover, the rate of recognition and treatment for depression is low. Therefore, the detection and treatment of depression are urgent. Multichannel electroencephalogram (EEG) signals, which reflect the working status of the human brain, can be used to develop an objective and promising tool for augmenting the clinical effects in the diagnosis and detection of depression. However, when a large number of EEG channels are acquired, the information redundancy and computational complexity of the EEG signals increase; thus, effective channel selection algorithms are required not only for machine learning feasibility, but also for practicality in clinical depression detection. Consequently, we propose an optimal channel selection method for EEG-based depression detection via kernel-target alignment (KTA) to effectively resolve the abovementioned issues. In this method, we consider a modified version KTA that can measure the similarity between the kernel matrix for channel selection and the target matrix as an objective function and optimize the objective function by a proposed optimal channel selection strategy. Experimental results on two EEG datasets show that channel selection can effectively increase the classification performance and that even if we rely only on a small subset of channels, the results are still acceptable. The selected channels are in line with the expected latent cortical activity patterns in depression detection. Moreover, the experimental results demonstrate that our method outperforms the state-of-the-art channel selection approaches.

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