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1.
J Mater Chem B ; 12(27): 6563-6569, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38899918

ABSTRACT

This paper outlines a novel drug delivery system for highly cytotoxic mertansine (DM1) by conjugating to an albumin-binding Evans blue (EB) moiety through a tuneable responsive disulfide linker, providing valuable insights for the development of effective drug delivery systems toward cancer therapy.


Subject(s)
Antineoplastic Agents , Drug Delivery Systems , Oxidation-Reduction , Humans , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Animals , Albumins/chemistry , Maytansine/chemistry , Maytansine/pharmacology , Mice , Neoplasms/drug therapy , Drug Carriers/chemistry , Cell Proliferation/drug effects , Cell Survival/drug effects , Drug Screening Assays, Antitumor
2.
Ecol Evol ; 13(11): e10672, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37920769

ABSTRACT

Aim: As invasive plants are often in a non-equilibrium expansion state, traditional species distribution models (SDMs) are likely underestimating their suitable habitat. New methods are necessary to identify potential invasion risk areas. Location: Tropical monsoon rainforest and subtropical evergreen broad-leaved forest regions in China. Methods: We took Parthenium hysterophorus as a case study to predict its potential invasion risk using climate, terrain, and human activity variables. First, a generalized joint attribute model (GJAM) was constructed using the occurrence of P. hysterophorus and its 27 closely related species in Taiwan, given it is widely distributed in Taiwan. Based on the output correlation values, two positively correlated species (Cardiospermum halicacabum and Portulaca oleracea) and one negatively correlated species (Crassocephalum crepidioides) were selected as indicator species. Second, the distributions of P. hysterophorus and its indicator species in the study area were predicted separately using an ensemble model (EM). Third, when selecting indicator species to construct indicator SDMs, two treatments (indicator species with positive correlation only, or both positive and negative correlation) were considered. The indicator species' EM predictions were overlaid using a weighted average method, and a better indicator SDMs prediction result was selected by comparison. Finally, the EM prediction result of P. hysterophorus was used to optimize the indicator SDMs result by a maximum overlay. Results: The optimized indicator SDMs prediction showed an expanded range beyond the current geographic range compared to EM and the thresholds for predicting key environmental variables were wider. It also reinforced the human activities' influence on the potential distribution of P. hysterophorus. Main Conclusions: For invasive plants with expanding ranges, information about indicator species distribution can be borrowed as a barometer for areas not currently invaded. The optimized indicator SDMs allow for more efficient potential invasion risk prediction. On this basis, invasive plants can be prevented earlier.

3.
Plants (Basel) ; 12(10)2023 May 09.
Article in English | MEDLINE | ID: mdl-37653840

ABSTRACT

Mangrove forests are one of the most productive and seriously threatened ecosystems in the world. The widespread invasion of Spartina alterniflora has seriously imperiled the security of mangroves as well as coastal mudflat ecosystems. Based on a model evaluation index, we selected RF, GBM, and GLM as a predictive model for building a high-precision ensemble model. We used the species occurrence records combined with bioclimate, sea-land topography, and marine environmental factors to predict the potentially suitable habitats of mangrove forests and the potentially suitable invasive habitats of S. alterniflora in the southeastern coast of China. We then applied the invasion risk index (IRI) to assess the risk that S. alterniflora would invade mangrove forests. The results show that the suitable habitats for mangrove forests are mainly distributed along the coastal provinces of Guangdong, Hainan, and the eastern coast of Guangxi. The suitable invasive habitats for S. alterniflora are mainly distributed along the coast of Zhejiang, Fujian, and relatively less in the southern provinces. The high-risk areas for S. alterniflora invasion of mangrove forests are concentrated in Zhejiang and Fujian. Bioclimate variables are the most important variables affecting the survival and distribution of mangrove forests and S. alterniflora. Among them, temperature is the most important environmental variable determining the large-scale distribution of mangrove forests. Meanwhile, S. alterniflora is more sensitive to precipitation than temperature. Our results can provide scientific insights and references for mangrove forest conservation and control of S. alterniflora.

4.
Math Biosci Eng ; 20(7): 12404-12432, 2023 May 23.
Article in English | MEDLINE | ID: mdl-37501448

ABSTRACT

This systematic review aims to investigate recent developments in the area of arc fault detection. The rising demand for electricity and concomitant expansion of energy systems has resulted in a heightened risk of arc faults and the likelihood of related fires, presenting a matter of considerable concern. To address this challenge, this review focuses on the role of artificial intelligence (AI) in arc fault detection, with the objective of illuminating its advantages and identifying current limitations. Through a meticulous literature selection process, a total of 63 articles were included in the final analysis. The findings of this review suggest that AI plays a significant role in enhancing the accuracy and speed of detection and allowing for customization to specific types of faults in arc fault detection. Simultaneously, three major challenges were also identified, including missed and false detections, the restricted application of neural networks and the paucity of relevant data. In conclusion, AI has exhibited tremendous potential for transforming the field of arc fault detection and holds substantial promise for enhancing electrical safety.

5.
Chem Commun (Camb) ; 59(58): 8911-8928, 2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37366367

ABSTRACT

The selective hydrolysis of the extremely stable phosphoester, peptide and ester bonds of molecules by bio-inspired metal-based catalysts (metallohydrolases) is required in a wide range of biological, biotechnological and industrial applications. Despite the impressive advances made in the field, the ultimate goal of designing efficient enzyme mimics for these reactions is still elusive. Its realization will require a deeper understanding of the diverse chemical factors that influence the activities of both natural and synthetic catalysts. They include catalyst-substrate complexation, non-covalent interactions and the electronic nature of the metal ion, ligand environment and nucleophile. Based on our computational studies, their roles are discussed for several mono- and binuclear metallohydrolases and their synthetic analogues. Hydrolysis by natural metallohydrolases is found to be promoted by a ligand environment with low basicity, a metal bound water and a heterobinuclear metal center (in binuclear enzymes). Additionally, peptide and phosphoester hydrolysis is dominated by two competing effects, i.e. nucleophilicity and Lewis acid activation, respectively. In synthetic analogues, hydrolysis is facilitated by the inclusion of a second metal center, hydrophobic effects, a biological metal (Zn, Cu and Co) and a terminal hydroxyl nucleophile. Due to the absence of the protein environment, hydrolysis by these small molecules is exclusively influenced by nucleophile activation. The results gleaned from these studies will enhance the understanding of fundamental principles of multiple hydrolytic reactions. They will also advance the development of computational methods as a predictive tool to design more efficient catalysts for hydrolysis, Diels-Alder reaction, Michael addition, epoxide opening and aldol condensation.


Subject(s)
Coordination Complexes , Metalloproteins , Hydrolysis , Coordination Complexes/chemistry , Ligands , Metalloproteins/chemistry , Peptides/chemistry , Metals/chemistry , Catalysis
6.
J Chem Inf Model ; 62(10): 2466-2480, 2022 05 23.
Article in English | MEDLINE | ID: mdl-35451306

ABSTRACT

In this study, chemical promiscuity of a binuclear metallohydrolase Streptomyces griseus aminopeptidase (SgAP) has been investigated using DFT calculations. SgAP catalyzes two diverse reactions, peptide and phosphoester hydrolyses, using its binuclear (Zn-Zn) core. On the basis of the experimental information, mechanisms of these reactions have been investigated utilizing leucine p-nitro aniline (Leu-pNA) and bis(4-nitrophenyl) phosphate (BNPP) as the substrates. The computed barriers of 16.5 and 16.8 kcal/mol for the most plausible mechanisms proposed by the DFT calculations are in good agreement with the measured values of 13.9 and 18.3 kcal/mol for the Leu-pNA and BNPP hydrolyses, respectively. The former was found to occur through the transfer of two protons, while the latter with only one proton transfer. They are in line with the experimental observations. The cleavage of the peptide bond was the rate-determining process for the Leu-pNA hydrolysis. However, the creation of the nucleophile and its attack on the electrophile phosphorus atom was the rate-determining step for the BNPP hydrolysis. These calculations showed that the chemical nature of the substrate and its binding mode influence the nucleophilicity of the metal bound hydroxyl nucleophile. Additionally, the nucleophilicity was found to be critical for the Leu-pNA hydrolysis, whereas double Lewis acid activation was needed for the BNPP hydrolysis. That could be one of the reasons why peptide hydrolysis can be catalyzed by both mononuclear and binuclear metal cofactors containing hydrolases, while phosphoester hydrolysis is almost exclusively by binuclear metallohydrolases. These results will be helpful in the development of versatile catalysts for chemically distinct hydrolytic reactions.


Subject(s)
Aminopeptidases , Peptides , Aminopeptidases/chemistry , Aminopeptidases/metabolism , Catalysis , Hydrolases , Hydrolysis , Metals , Peptides/chemistry
7.
Sci Total Environ ; 756: 143841, 2021 Feb 20.
Article in English | MEDLINE | ID: mdl-33248784

ABSTRACT

Ageratina adenophora, Eupatorium odoratum, and Mikania micrantha are three highly destructive invasive plants of Compositae in China. Through the screening of SDMs, random forest (RF), gradient boosting model (GBM), artificial neural network (ANN), and flexible discriminant analysis (FDA) with TSS greater than 0.8 are selected to construct a high-precision ensemble model (EM) as the prediction model. We use specimen sites and environmental variables containing climate, soil, terrain, and human activities to simulate and predict the invasion trend of three invasive weeds in China in current, the 2050s, and the 2070s. Results indicate that the highly invasive risk area of three exotic plants is mostly distributed along the river in the provinces south of 30° N. In the future scenario, the three exotic plants obviously invade northwards Yunnan, Sichuan, Guizhou, Jiangxi and Fujian. Climate is the most important variable that affects the spread of three kinds of alien plant invasions. Temperature and precipitation variables have a similar effect on A. adenophora and E. odoratum, while M. micrantha is more sensitive to temperature. It has been reported that Ipomoea batatas and Vitex negundo can prevent the invasion of three invasive plants. Hence, we also simulate the suitable planting areas for I. batatas and V. negundo. The results show that I. batatas and V. negundo are suitable to be planted in the areas where the three weeds show invasion tendency. In the paper, predicting invasion trends of exotic plants and simulating the planting suitability of crops that can block invasion, to provide a practical significance reference and suggestion for the management, prevention, and control of the invasion of exotic plants in China.


Subject(s)
Asteraceae , Mikania , China , Climate Change , Humans , Introduced Species , Soil
8.
Springerplus ; 5(1): 1150, 2016.
Article in English | MEDLINE | ID: mdl-27504248

ABSTRACT

This paper explores lane changing trajectory planning and tracking control for intelligent vehicle on curved road. A novel arcs trajectory is planned for the desired lane changing trajectory. A kinematic controller and a dynamics controller are designed to implement the trajectory tracking control. Firstly, the kinematic model and dynamics model of intelligent vehicle with non-holonomic constraint are established. Secondly, two constraints of lane changing on curved road in practice (LCCP) are proposed. Thirdly, two arcs with same curvature are constructed for the desired lane changing trajectory. According to the geometrical characteristics of arcs trajectory, equations of desired state can be calculated. Finally, the backstepping method is employed to design a kinematic trajectory tracking controller. Then the sliding-mode dynamics controller is designed to ensure that the motion of the intelligent vehicle can follow the desired velocity generated by kinematic controller. The stability of control system is proved by Lyapunov theory. Computer simulation demonstrates that the desired arcs trajectory and state curves with B-spline optimization can meet the requirements of LCCP constraints and the proposed control schemes can make tracking errors to converge uniformly.

9.
Springerplus ; 5: 448, 2016.
Article in English | MEDLINE | ID: mdl-27119052

ABSTRACT

This paper proposes a novel continuous sparse autoencoder (CSAE) which can be used in unsupervised feature learning. The CSAE adds Gaussian stochastic unit into activation function to extract features of nonlinear data. In this paper, CSAE is applied to solve the problem of transformer fault recognition. Firstly, based on dissolved gas analysis method, IEC three ratios are calculated by the concentrations of dissolved gases. Then IEC three ratios data is normalized to reduce data singularity and improve training speed. Secondly, deep belief network is established by two layers of CSAE and one layer of back propagation (BP) network. Thirdly, CSAE is adopted to unsupervised training and getting features. Then BP network is used for supervised training and getting transformer fault. Finally, the experimental data from IEC TC 10 dataset aims to illustrate the effectiveness of the presented approach. Comparative experiments clearly show that CSAE can extract features from the original data, and achieve a superior correct differentiation rate on transformer fault diagnosis.

10.
Sensors (Basel) ; 16(2): 189, 2016 Feb 04.
Article in English | MEDLINE | ID: mdl-26861319

ABSTRACT

This paper provides an approach for recognizing human activities with wearable sensors. The continuous autoencoder (CAE) as a novel stochastic neural network model is proposed which improves the ability of model continuous data. CAE adds Gaussian random units into the improved sigmoid activation function to extract the features of nonlinear data. In order to shorten the training time, we propose a new fast stochastic gradient descent (FSGD) algorithm to update the gradients of CAE. The reconstruction of a swiss-roll dataset experiment demonstrates that the CAE can fit continuous data better than the basic autoencoder, and the training time can be reduced by an FSGD algorithm. In the experiment of human activities' recognition, time and frequency domain feature extract (TFFE) method is raised to extract features from the original sensors' data. Then, the principal component analysis (PCA) method is applied to feature reduction. It can be noticed that the dimension of each data segment is reduced from 5625 to 42. The feature vectors extracted from original signals are used for the input of deep belief network (DBN), which is composed of multiple CAEs. The training results show that the correct differentiation rate of 99.3% has been achieved. Some contrast experiments like different sensors combinations, sensor units at different positions, and training time with different epochs are designed to validate our approach.

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