Small extracellular vesicles(exosomes)are important components of the tumor microenvironment.They are small membrane-bound vesicles derived from almost all cell types and play an important role in intercellular commun...Small extracellular vesicles(exosomes)are important components of the tumor microenvironment.They are small membrane-bound vesicles derived from almost all cell types and play an important role in intercellular communication.Exosomes transmit biological molecules obtained from parent cells,such as proteins,lipids,and nucleic acids,and are involved in cancer development.MicroRNAs(miRNAs),the most abundant contents in exosomes,are selectively packaged into exosomes to carry out their biological functions.Recent studies have revealed that exosome-delivered miRNAs play crucial roles in the tumorigenesis,progression,and drug resistance of hepatocellular carcinoma(HCC).In addition,exosomes have great industrial prospects in the diagnosis,treatment,and prognosis of patients with HCC.This review summarized the composition and function of exosomal miRNAs of different cell origins in HCC and highlighted the association between exosomal miRNAs from stromal cells and immune cells in the tumor microenvironment and the progression of HCC.Finally,we described the potential applicability of exosomal miRNAs derived from mesenchymal stem cells in the treatment of HCC.展开更多
Theoretical study of structural stability and elastic properties ofα-andβ-MgPd_(3)intermetallic compounds as well as their hydrides have been carried out based on density functional theory.The results indicateα-MgP...Theoretical study of structural stability and elastic properties ofα-andβ-MgPd_(3)intermetallic compounds as well as their hydrides have been carried out based on density functional theory.The results indicateα-MgPd_(3)is more stable thanβphase with increased stability in their hydrides.The calculated elastic constants ofα-MgPd_(3)are overall larger thanβphase.After hydrogenation,the elastic constants are enlarged.And the elastic moduli exhibit similar tendency.The anisotropy ofα-MgPd_(3)is larger thanβphase,and the hydrides demonstrate larger anisotropy.Their ductility follows the order ofα-MgPd_(3)H_(0.5)<α-MgPd_(3)<β-MgPd_(3)H<β-MgPd_(3).Compared withβphase,higher Debye temperature ofα-MgPd_(3)implies stronger covalent interaction,and the Debye temperature of hydrides increases slightly.The electronic structures demonstrate that the Pd-Pd interaction is stronger than Pd-Mg,and Pd-H bonds play a significant role in the phase stability and elastic properties of hydrides.展开更多
Garnets have found important applications in modern technologies including magnetorestriction,spintronics,lithium batteries,etc.The overwhelming majority of experimentally known garnets are oxides,while explorations(e...Garnets have found important applications in modern technologies including magnetorestriction,spintronics,lithium batteries,etc.The overwhelming majority of experimentally known garnets are oxides,while explorations(experimental or theoretical)for the rest of the chemical space have been limited in scope.A key issue is that the garnet structure has a large primitive unit cell,requiring a substantial amount of computational resources.To perform a comprehensive search of the complete chemical space for new garnets,we combine recent progress in graph neural networks with high-throughput calculations.We apply the machine learning model to identify the potentially(meta-)stable garnet systems before performing systematic density-functional calculations to validate the predictions.We discover more than 600 ternary garnets with distances to the convex hull below 100 meV⋅atom−1.This includes sulfide,nitride,and halide garnets.We analyze their electronic structure and discuss the connection between the value of the electronic band gap and charge balance.展开更多
Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) have been a challenging concern of health-care associated infections. The aim of the current study was to investigate the molecular epidemiology and clon...Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) have been a challenging concern of health-care associated infections. The aim of the current study was to investigate the molecular epidemiology and clonal dissemination of CRAB isolates in a Chinese teaching hospital. Methods: Non-duplicate clinical A. baumannii isolates were collected from inpatients, and we measured the minimal inhibitory concentrations to determine antimicrobial susceptibility. Polymerase chain reaction (PCR) and sequencing were performed to detect carbapenem-resistance genes and occurrence of transposons among CRAB isolates. Moreover, the genetic diversity among isolates and clonal dissemination were determined by repetitive element PCR-mediated DNA fingerprinting (rep-PCR) and multilocus sequence typing (MLST). Results: A total of 67 CRAB isolates displayed resistance to most of the antibiotics tested in this study, except tigecycline. We detected bldOXA-23,bldOXA-51, bldOXAA-58, and bldVIM genes in 94.0%, 100.0%, 1.5%, and 80.6% of the CRAB isolates, respectively. Nevertheless, 74.6% of the CRAB isolates co-harbored the bldOXA-23 and bldVIM. Only one type of transposons was detected: Tn2008 (79.1%, 53/67). Although 12 distinctive types (A-L) were determined (primarily A type) STI95 was the most prevalent sequence type (ST). ST368, ST210, ST90, ST829, and ST136 were also detected, and all belonged to clonal complex 208 (CC208) and global complex 2 (GC2). Conclusion: The bldOXA-23 and bldVIM genes contributed to the resistance among CRAB isolates collected in our study. Notably, most of the CRAB strains co-harbored bldOXA-23 and vim genes, as well as Tn2008, which could contribute to clonal dissemination. The prevalence of such organisms may underlie hospital acquired infections.展开更多
In this work,we present a large-scale study of gap deformation potentials based on density-functional theory calculations for over 5000 semiconductors.As expected,in most cases the band gap decreases for increasing vo...In this work,we present a large-scale study of gap deformation potentials based on density-functional theory calculations for over 5000 semiconductors.As expected,in most cases the band gap decreases for increasing volume with deformation potentials that can reach values of almost−15 eV.We find,however,also a sizeable number of materials with positive deformation potentials.Notorious members of this group are halide perovskites,known for their applications in photovoltaics.We then focus on understanding the physical reasons for so different values of the deformation potentials by investigating the correlations between this property and a large number of other material and compositional properties.We also train explainable machine learning models as well as graph convolutional networks to predict deformation potentials and establish simple rules to understand predicted values.Finally,we analyze in more detail a series of materials that have record positive and negative deformation potentials.展开更多
We propose an efficient high-throughput scheme for the discovery of stable crystalline phases.Our approach is based on the transmutation of known compounds,through the substitution of atoms in the crystal structure wi...We propose an efficient high-throughput scheme for the discovery of stable crystalline phases.Our approach is based on the transmutation of known compounds,through the substitution of atoms in the crystal structure with chemically similar ones.The concept of similarity is defined quantitatively using a measure of chemical replaceability,extracted by data-mining experimental databases.In this way we build 189,981 possible crystal phases,including 18,479 that are on the convex hull of stability.The resulting success rate of 9.72%is at least one order of magnitude better than the usual success rate of systematic high-throughput calculations for a specific family of materials,and comparable with speed-up factors of machine learning filtering procedures.As a characterization of the set of 18,479 stable compounds,we calculate their electronic band gaps,magnetic moments,and hardness.Our approach,that can be used as a filter on top of any high-throughput scheme,enables us to efficiently extract stable compounds from tremendously large initial sets,without any initial assumption on their crystal structures or chemical compositions.展开更多
基金the National Natural Science Foundation of China,No.81761128018 and No.81572871the Natural Science Foundation of Jiangsu Province,No.BK20151277and the Undergraduate Training Programs for Innovation and Entrepreneurship of Jiangsu Province,No.202110304035Z.
文摘Small extracellular vesicles(exosomes)are important components of the tumor microenvironment.They are small membrane-bound vesicles derived from almost all cell types and play an important role in intercellular communication.Exosomes transmit biological molecules obtained from parent cells,such as proteins,lipids,and nucleic acids,and are involved in cancer development.MicroRNAs(miRNAs),the most abundant contents in exosomes,are selectively packaged into exosomes to carry out their biological functions.Recent studies have revealed that exosome-delivered miRNAs play crucial roles in the tumorigenesis,progression,and drug resistance of hepatocellular carcinoma(HCC).In addition,exosomes have great industrial prospects in the diagnosis,treatment,and prognosis of patients with HCC.This review summarized the composition and function of exosomal miRNAs of different cell origins in HCC and highlighted the association between exosomal miRNAs from stromal cells and immune cells in the tumor microenvironment and the progression of HCC.Finally,we described the potential applicability of exosomal miRNAs derived from mesenchymal stem cells in the treatment of HCC.
基金The financial support from the National Natural Science Foundation of China(51071053)is appreciated gratefully.
文摘Theoretical study of structural stability and elastic properties ofα-andβ-MgPd_(3)intermetallic compounds as well as their hydrides have been carried out based on density functional theory.The results indicateα-MgPd_(3)is more stable thanβphase with increased stability in their hydrides.The calculated elastic constants ofα-MgPd_(3)are overall larger thanβphase.After hydrogenation,the elastic constants are enlarged.And the elastic moduli exhibit similar tendency.The anisotropy ofα-MgPd_(3)is larger thanβphase,and the hydrides demonstrate larger anisotropy.Their ductility follows the order ofα-MgPd_(3)H_(0.5)<α-MgPd_(3)<β-MgPd_(3)H<β-MgPd_(3).Compared withβphase,higher Debye temperature ofα-MgPd_(3)implies stronger covalent interaction,and the Debye temperature of hydrides increases slightly.The electronic structures demonstrate that the Pd-Pd interaction is stronger than Pd-Mg,and Pd-H bonds play a significant role in the phase stability and elastic properties of hydrides.
文摘Garnets have found important applications in modern technologies including magnetorestriction,spintronics,lithium batteries,etc.The overwhelming majority of experimentally known garnets are oxides,while explorations(experimental or theoretical)for the rest of the chemical space have been limited in scope.A key issue is that the garnet structure has a large primitive unit cell,requiring a substantial amount of computational resources.To perform a comprehensive search of the complete chemical space for new garnets,we combine recent progress in graph neural networks with high-throughput calculations.We apply the machine learning model to identify the potentially(meta-)stable garnet systems before performing systematic density-functional calculations to validate the predictions.We discover more than 600 ternary garnets with distances to the convex hull below 100 meV⋅atom−1.This includes sulfide,nitride,and halide garnets.We analyze their electronic structure and discuss the connection between the value of the electronic band gap and charge balance.
基金grants from Hunan Development and Reform Investment from the Development and Reform Commission of the Hunan Province，the Natural Science Foundation of the Hunan Province
基金grants from the Hunan Provincial Natural Science Foundation (No. 2017JJ3478)the National Natural Science Foundation of China (No. 81702068).
文摘Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) have been a challenging concern of health-care associated infections. The aim of the current study was to investigate the molecular epidemiology and clonal dissemination of CRAB isolates in a Chinese teaching hospital. Methods: Non-duplicate clinical A. baumannii isolates were collected from inpatients, and we measured the minimal inhibitory concentrations to determine antimicrobial susceptibility. Polymerase chain reaction (PCR) and sequencing were performed to detect carbapenem-resistance genes and occurrence of transposons among CRAB isolates. Moreover, the genetic diversity among isolates and clonal dissemination were determined by repetitive element PCR-mediated DNA fingerprinting (rep-PCR) and multilocus sequence typing (MLST). Results: A total of 67 CRAB isolates displayed resistance to most of the antibiotics tested in this study, except tigecycline. We detected bldOXA-23,bldOXA-51, bldOXAA-58, and bldVIM genes in 94.0%, 100.0%, 1.5%, and 80.6% of the CRAB isolates, respectively. Nevertheless, 74.6% of the CRAB isolates co-harbored the bldOXA-23 and bldVIM. Only one type of transposons was detected: Tn2008 (79.1%, 53/67). Although 12 distinctive types (A-L) were determined (primarily A type) STI95 was the most prevalent sequence type (ST). ST368, ST210, ST90, ST829, and ST136 were also detected, and all belonged to clonal complex 208 (CC208) and global complex 2 (GC2). Conclusion: The bldOXA-23 and bldVIM genes contributed to the resistance among CRAB isolates collected in our study. Notably, most of the CRAB strains co-harbored bldOXA-23 and vim genes, as well as Tn2008, which could contribute to clonal dissemination. The prevalence of such organisms may underlie hospital acquired infections.
基金S.B.acknowledges the financial support from the Volkswagen Stiftung(Momentum)through the project“dandelion”P.B.acknowledges the financial support from the CFisUC through the project UIDB/04564/2020 and FCT under the contract 2020.04225.CEECIND.
文摘In this work,we present a large-scale study of gap deformation potentials based on density-functional theory calculations for over 5000 semiconductors.As expected,in most cases the band gap decreases for increasing volume with deformation potentials that can reach values of almost−15 eV.We find,however,also a sizeable number of materials with positive deformation potentials.Notorious members of this group are halide perovskites,known for their applications in photovoltaics.We then focus on understanding the physical reasons for so different values of the deformation potentials by investigating the correlations between this property and a large number of other material and compositional properties.We also train explainable machine learning models as well as graph convolutional networks to predict deformation potentials and establish simple rules to understand predicted values.Finally,we analyze in more detail a series of materials that have record positive and negative deformation potentials.
基金S.B.and M.A.L.M.acknowledge financial support from the DFG through Projects MA 6787/1-1,and BO 4280/8.
文摘We propose an efficient high-throughput scheme for the discovery of stable crystalline phases.Our approach is based on the transmutation of known compounds,through the substitution of atoms in the crystal structure with chemically similar ones.The concept of similarity is defined quantitatively using a measure of chemical replaceability,extracted by data-mining experimental databases.In this way we build 189,981 possible crystal phases,including 18,479 that are on the convex hull of stability.The resulting success rate of 9.72%is at least one order of magnitude better than the usual success rate of systematic high-throughput calculations for a specific family of materials,and comparable with speed-up factors of machine learning filtering procedures.As a characterization of the set of 18,479 stable compounds,we calculate their electronic band gaps,magnetic moments,and hardness.Our approach,that can be used as a filter on top of any high-throughput scheme,enables us to efficiently extract stable compounds from tremendously large initial sets,without any initial assumption on their crystal structures or chemical compositions.
