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A full set of 8,4'-oxy-8'-phenylneolignans with four chiral carbons, named (+)/(-)-leptolepisols D1‒D2 and (+)/(-)-sophorols A‒F, were isolated from the roots and rhizomes of Sophora tonkinensis Gagnep., including 14 previously undescribed stereoisomers, along with 2 known leptolepisol D diastereomers. Their planar structures and relative configurations were elucidated by detailed spectroscopic analysis (HRESIMS and NMR). Based on a highly accurate conformer filtering protocol at low computational cost, the absolute configurations of full set 8,4'-oxy-8'-phenylneolignans were completely assigned by TDDFT calculations of ECD spectra for the first time. Furthermore, (+)/(-)-sophorol A, (-)-sophorol B, and (-)-sophorol E could moderately suppress the lipopolysaccharide-induced nitric oxide production in murine macrophages at 10 μM, with inhibitory ratios of 48.4-52.9%.

A visible-light-triggered radical cascade sulfonylation/aryl migration/desulfonylation and C-S/Se bond formation reaction of butenyl benzothiazole sulfone with thiosulfonates or selenosulfonates is developed. This study affords the 1,2,4-trifunctionalization of butenyl benzothiazole sulfone derivatives under mild conditions.

Two new furoquinoline alkaloids, named 1'-oxo-isoplatydesmine (

In traditional brain-computer interfaces (BCIs), using only a certain type of feature or a simple mixture of different features cannot meet the requirements for high performance in classification. Moreover, a simple mixture of various features might lead to information redundancies and thus increase the computational complexity. In this paper, we studied the feasibility of integrating two kinds of features, which showed opposite variation trends as the memory load levels increase, into a single fusion feature. We also proposed a feature fusion framework based on non-invasive electroencephalography to classify the memory load levels and estimate the workload for a series of challenging working memory (WM) tasks (involving delayed match-to-sample tasks) on a single-trial basis. A novel fusion feature called spectral entropy/Lempel-Ziv complexity ( SEn / LZC ) was proposed to classify three memory load levels. The results showed that the generalization of the support vector machine (SVM) with SEn / LZC was significantly higher than the generalization of an SVM with four other types of feature, namely SEn , LZC, SEn & LZC and LZC / SEn . The findings suggested that the proposed fusion feature could act as a biomarker to successfully distinguish different load levels and that the constructed framework could achieve consistency between optimal cognitive performance and fusion features. In addition, the proposed fusion framework could provide a new method of successfully promoting the classification generalization of BCI and implicitly evaluating the mental workload.

In this study, four functionalized metal–organic frameworks (MOFs) composite (UiO-66-COOCH3, UiO-66-CONH2, UiO-66-CN and UiO-66-SO3H) were successfully prepared by post-synthesis modification for the removal of Co(II) from simulated 60Co radioactive wastewater. Benefiting from the strong uptake ability of these functional MOFs, the as-synthesized MOFs adsorbents exhibit an extraordinary adsorption performance towards Co(II), and their saturated adsorption capacity reached 334.4 mg g−1 (UiO-66-COOCH3), 339.7 mg g−1 (UiO-66-CONH2), 274.6 mg g−1 (UiO-66-CN) and 293.7 mg g−1 (UiO-66-SO3H), respectively. In addition, density functional theory (DFT) was used to study the adsorption mechanism of Co(II) by MOFs. The results of theoretical calculation revealed that the functional groups of MOFs have strong chelating ability to Co(II), which gradually increase with the order of nitrile group, sulfonic acid group, ester group and amide group, and the order is also consistent with the adsorption amount of Co(II) in the experiment. All these works suggest that the synthesized MOFs are potential candidate for 60Co seperation.

C19-diterpenoid alkaloids have complex and diverse structures, posing great challenges for nuclear magnetic resonance (NMR)-based structural elucidation. Three C19-diterpenoid alkaloids, including taronenine E (1), chasmaconitine (2) and vilmorisine (3), were isolated from the roots of Aconitum taronense Fletcher et Lauener, and analyzed by various NMR spectroscopy methods (i.e., 1H and 13C NMR, DEPT, 1H-1H COSY, HSQC and HMBC). Complete assignments of the NMR chemical shifts were obtained, providing a good reference for the further research of C19-diterpenoid alkaloids.

There is growing evidence that the amygdala serves as the base for dealing with complex human social communication and emotion. Although amygdalar networks plays a central role in these functions, causality connectivity during the human lifespan between amygdalar subregions and their corresponding perception network (PerN), affiliation network (AffN) and aversion network (AveN) remain largely unclear. Granger causal analysis (GCA), an approach to assess directed functional interactions from time series data, was utilized to investigated effective connectivity between amygdalar subregions and their related networks as a function of age to reveal the maturation and degradation of neural circuits during development and ageing in the present study. For each human resting functional magnetic resonance imaging (fMRI) dataset, the amygdala was divided into three subareas, namely ventrolateral amygdala (VLA), medial amygdala (MedA) and dorsal amygdala (DorA), by using resting-state functional connectivity, from which the corresponding networks (PerN, AffN and AveN) were extracted. Subsequently, the GC interaction of the three amygdalar subregions and their associated networks during life were explored with a generalised linear model (GLM). We found that three causality flows significantly varied with age: the GC of VLA → PerN showed an inverted U-shaped trend with ageing; the GC of MedA→ AffN had a U-shaped trend with ageing; and the GC of DorA→ AveN decreased with ageing. Moreover, during ageing, the above GCs were significantly correlated with Social Responsiveness Scale (SRS) and State-Trait Anxiety Inventory (STAI) scores. In short, PerN, AffN and AveN associated with the amygdalar subregions separately presented different causality connectivity changes with ageing. These findings provide a strong constituent framework for normal and neurological diseases associated with social disorders to analyse the neural basis of social behaviour during life.

Cytochalasins are a group of natural products from fungus, and have been attracting lots of research interests in the field of microbiology. Cytochalasins possess complex and diverse structures, making nuclear magnetic resonance (NMR) based structure elucidation difficult. Chaetoglobosin F is a 10-indol cytochalasin isolated from endophytic Chaetomium globosum growing in the seeds of Panax notoginseng. This paper reported the NMR data chaetoglobosin F, along with the summarization of NMR features of 10-indol cytochalasins, providing a good reference for the further research on cytochalasins.

Majority of diterpenoid alkaloids are C19-diterpenoid alkaloids found in the plants from the genera Aconitum, Delphinium and Consolida (Ranunculaceae). C19-diterpenoid alkaloids have attached lots of research interests due to their complex structures and remarkable pharmacological activities. This paper reviewed the structural features of natural C19-diterpenoid alkaloids reported in literature from 2010 to 2018, focusing on the NMR spectral characteristics of different subtypes of C19-diterpenoid alkaloids and how their structures could be elucidated from the NMR data. The work may provide a reference for the further research and development of C19-diterpenoid alkaloids.

Disclosing the complex relationships effectively between paired brain regions played a significant role in measuring the brain functional connectivity and exploring brain topological structures. Even though Pearson correlation coefficient (PCC) has been widely used to construct functional brain networks in the previous studies, it was mainly sensitive to linear associations. Therefore, maximal information coefficient (MIC) was first utilized to make up this weakness of PCC to construct electroencephalography (EEG) connectivity in the current study. The simulation results showed that MIC could capture certain relationships which PCC failed to detect. Furthermore, brain network properties changed with various thresholds under the resting-state EEG, and the comparison analysis of network properties illustrated that MIC and PCC could capture different aspects of connections between paired brain regions. These findings indicated that MIC could be a complementary method of PCC for the construction of scalp resting-state EEG connectome and provided a novel tool to reveal the potential mechanisms of brain networks.

N2pc is defined as a negative event-related potential component that appears after about 250 ms at posterior electrodes contralateral to a target’s location in visual search, which can be used to measure attentional shifts between bilateral visual hemifields and locate the spatial location of lateral targets. However, the waves between the left and right hemispheres elicited by lateral targets usually exhibit a small amplitude difference and strong synchronicity, which may lead to low classification performance. Therefore, the present study explored the feasibility of a multiple correlated components analysis (MCORCA) methods to identify the lateral targets in visual search tasks with a single trial, which could weight the target signals by spatial filters to enlarge the amplitude difference between bilateral hemispheres and extract the linear combinations of multiple channels across trials with an optimal subset of correlated components to avoid the loss of efficient information. The classification rate achieved 82% with a single short-duration trial when using the proposed method with Leave-one-out-cross-validation (LOOCV). The findings demonstrated that the MCORCA-based methods could be used to improve the classification performance for the N2pc-based brain-computer interfaces (BCI) in visual search.

Cynomorium coccineum subsp. songaricum (Rupr.) J. Leonard has been widely used as a Chinese herbal remedy or a functional food for treating symptoms of aging or neurodegenerative diseases. A further investigation on the finding of active constituents led to the isolation and identification of four previously undescribed triterpenoids, together with 20 known compounds. Their structures were elucidated by extensive spectroscopic analysis (IR, NMR, HRMS, and CD). Sixteen compounds showed significant neuroprotective effects against glutamate-induced or oxygen-glucose deprivation-induced SK-N-SH cell death. Our findings revealed the active constituents of C. coccineum subsp. songaricum and indicated that both oleanane-type and ursane-type triterpenes could be valuable platforms for neurodegenerative agents based on primary structure-activity relationship analysis.

Knowledge of uranyl (UO22+) aqueous speciation and chemical interactions with natural organic matter is the basis to mode the sorption and transport behavior of uranyl. Anserine is a natural dipeptide containing β-alanine and 1-methylhistidine, which can be found in the skeletal muscle of birds and certain species of mammals. The complexation of anserine with uranyl cation was studied thermodynamically and structurally at 25 °C, I = 0.5 mol·L−1 NaCl solution. Protonation of anserine was investigated by potentiometry, microcalorimetry and NMR spectroscopy. Experimental results confirmed that there are three successive proton reaction steps for a totally deproton anserine. The order of successive protonation sites are the terminal amine nitrogen atom of alanine, amine nitrogen atoms in imidazole ring, and finally carboxylate oxygen. This trend is in agreement with exothermic enthalpies of protonation reaction. Potentiometry was used to measure stability constant of uranyl complex in solution. Thermodynamic studies identified four uranyl/anserine complexes with different degrees of deprotonation, UO2(HL)2+, UO2L+, UO2L2(aq) and UO2(OH)L2−. Coordination modes of the three complexes [UO2(HL)2+, UO2L+ and UO2L2(aq)] were investigated by NMR spectroscopy. In these complexes, anserine holds a tridentate mode. Cyclic voltammetry was performed to understand the influence of anserine exert over redox response to uranium in solution. The results confirmed that oxidation state of uranyl cation is stabilized significantly and harder to be reduced by complex with anserine. Anserine could effectively suppress the hydrolysis of uranyl in aqueous solutions.

To study the relationship between osteonecrosis of femoral head after internal fixation of femoral neck fracture and serum bone metabolism, vascular active factors, and analyze the risk factors.Total 150 patients with femoral neck fracture who underwent reduction and internal fixation from April 2016 to April 2019 were selected, including 83 males and 67 females. According to whether there was necrosis of femoral head after operation, they were divided into necrosis group(32 cases) and non necrosis group (118 cases). Before operation and 1, 3, 5 days after operation, the serum levels of beta-C terminal cross-linked telopeptides of typeⅠ collagen(β-CTX), N-telopeptide of typeⅠ procollagen(PINP), nitric oxide (NO), Endothelin-1 (ET-1) were measured. The clinical characteristics of the two groups were compared. The risk factors of postoperative femoral head necrosis were analyzed by logistic regression model. The value of serum indexes in predicting postoperative femoral head necrosis was analyzed by ROC curve.There was no significant difference in the levels of serum PINP and β-CTX between necrotic group and non necrotic group before operation and 1, 3 and 5 days after operation(The content of serum NO and ET-1 on the first day after operation can predict the necrosis of femoral head.

Nrf2 is the key transcription factor mainly for regulating oxidative homeostasis and cytoprotective responses against oxidative stress. Nrf2/Keap1 pathway is one of the most important cellular defense mechanisms against endogenous or exogenous oxidative stress. With its activation, a wide range of stress-related genes is transactivated to restore the cellular homeostasis. Recent studies revealed that the aberrant activation of Nrf2 is related to the malignant progression, chemotherapeutic drug resistance and poor prognosis. Nrf2 plays a crucial role in cancer malignancy and chemotherapeutic resistance by controlling the intracellular redox homeostasis through the activation of cytoprotective antioxidant genes. Nrf2 inhibitor containing many natural products has been deemed as a novel therapeutic strategy for human malignancies. This article reviews the progress of studies of the Nrf2/Keap1 pathway, and its biological impact in solid malignancies and molecular mechanisms for causing Nrf2 hyperactivation in cancer cells. In conclusion, we summarized the deve-lopment of Nrf2 inhibitors in recent years, in the expectation of providing reference for further drug development and clinical studies.