81 research outputs found
Macrochirality of Self-Assembled and Co-assembled Supramolecular Structures of a Pair of Enantiomeric Peptides
Although macrochirality of peptides’ supramolecular structures has been found to play important roles in biological activities, how macrochirality is determined by the molecular chirality of the constituted amino acids is still unclear. Here, two chiral peptides, Ac-LKLHLHLQLKLLLVLFLFLALK-NH2 (KK-11) and Ac-DKDHDHDQDKDL DVDFDFDADK-NH2 (KKd-11), which were composed entirely of either L- or D-amino acids, were designed for studying the chiral characteristics of the supramolecular microstructures. It was found that monocomponent KK-11 or KKd-11 self-assembled into right- or left-handed helical nanofibrils, respectively. However, when they co-assembled with concentration ratios varied from 1:9 to 9:1, achiral nanowire-like structures were formed. Both circular dichroism and Fourier transform infrared spectra indicated that the secondary structures changed when the peptides co-assembled. MD simulations indicated that KK-11 or KKd-11 exhibited a strong propensity to self-assemble into right-handed or left-handed nanofibrils, respectively. However, when KK-11 and KKd-11 were both presented in a solution, they had a higher probability to co-assemble instead of self-sort. MD simulations indicated that, in their mixtures, they formed nanowires without handedness feature, a good agreement with experimental observation. Our results shed light on the molecular mechanisms of the macrochirality of peptide supramolecular microstructures
YY1 Positively Regulates Transcription by Targeting Promoters and Super-Enhancers through the BAF Complex in Embryonic Stem Cells
Yin Yang 1 (YY1) regulates early embryogenesis and adult tissue formation. However, the role of YY1 in stem cell regulation remains unclear. YY1 has a Polycomb group (PcG) protein-dependent role in mammalian cells. The PcG-independent functions of YY1 are also
reported, although their underlying mechanism is still undefined. This paper reports the role of YY1 and BAF complex in the OCT4-mediated pluripotency network in mouse embryonic stem cells (mESCs). The interaction between YY1 and BAF complex promotes mESC proliferation and pluripotency. Knockdown of Yy1 or Smarca4, the core component of the BAF complex, downregulates pluripotency
markers and upregulates several differentiation markers. Moreover, YY1 enriches at both promoter and super-enhancer regions to stimulate transcription. Thus, this study elucidates the role of YY1 in regulating pluripotency through its interaction with OCT4 and the BAF
complex and the role of BAF complex in integrating YY1 into the core pluripotency networkThis research was funded by grants from the National Key
Research and Development Program (2016YFA [0101700] and
2017YFA0102800), the National Natural Science Foundation of
China (31771639), the Guangdong Innovative and Entrepreneurial Research Team Program 2016ZT06S029, the Fundamental
Research Funds for the Central Universities (17ykzd04), and Thousand Youth Talents Plan to J.D., the National Natural Science Foundation of China (81703086) to J.W. and the NIH (1R01-GM095942
and 1R21HD087722) and the Empire State Stem Cell funded
through the New York State Department of Health (NYSTEM;
C028103 and C028121) to J.W.S
Hypoxia attenuates Hsp90 inhibitor 17-DMAG-induced cyclin B1 accumulation in hepatocellular carcinoma cells
Particle Design of Membrane Emulsification for Protein Drug and Vaccine Delivery
Biodegradable particles have important applications in Drug Delivery Systems (DDS) of protein/peptide drugs. And recently, particle systems have also showed to be powerful for vaccine delivery (adjuvant) in order to solve the difficulties when conventional Alum adjuvant was used. However, in above applications, the problems of broad size distribution and poor reproducibility of particles, and deactivation of protein during the preparation, storage and release, are still big challenges. Furthermore, particle should be designed specially according to antigen type and purpose in vaccine delivery. In this article, the techniques to control the diameter of microparticle (MP) will be introduced at the first, and then the strategies about how to maintain the bioactivity of protein drugs during preparation and drug release will be reviewed. Furthermore, particle application specially designed for vaccine delivery to enhance both humoral response and cellular response, will be described
Compound Structures of Periodic Holes and Curved Ripples Fabricated by the Interference between the Converging Surface Plasmon Polaritons and Femtosecond Laser
Non-cylindrical vectorial femtosecond lasers are employed to irradiate tungsten surfaces. Compound nanopatterns composed of periodic nanoholes and semi-circular curved ripples are produced by scanning the target relative to the laser beam. The tangential direction of the curved ripples is perpendicular to the local polarization direction of the vectorial femtosecond laser beam. Therefore, the formation mechanism of the curved ripples can be attributed to the interference between the incident femtosecond laser and the laser-induced surface plasmon polaritons (SPPs). We found that, in addition to the curved ripples, periodic nanoholes with an average diameter of 406 nm also appeared on the target surface, and they all tended to appear at the vertexes of the semi-circular curved ripples, i.e., the converging point of SPPs. Further experiments demonstrated that the location of the periodic nanoholes was totally determined by the polarization state of the incident femtosecond laser. Therefore, we deduced that the convergent SPPs induced by the non-cylindrical vectorial femtosecond laser interfered with the incident laser at the convergent point, leading to the generation of periodic nanoholes. The investigations in this work exhibited the important role of manipulating the propagation of SPPs in femtosecond laser surface structuring, which not only diversifies the surface patterns that can be produced by laser-induced periodic surface structuring (LIPSS) but also provides deep insights in the excitation and propagation dynamics of SPPs
Homogeneous PLGA-lipid nanoparticle as a promising oral vaccine delivery system for ovalbumin
In this study, a polymeric lipid nanoparticle (NP) (simplified as Lipid NP) was reported as a promising oral vaccine delivery system. The Lipid NPs composed of a hydrophobic polymeric poly(d,l-lactide-co-glycolide) (PLGA) core and a surface coating of lipid monolayer. Membrane emulsification technique was used to obtain uniform-sized Lipid NPs. Ovalbumin (OVA) was used as a model vaccine. Compared with the pure PLGA NPs, the Lipid NPs achieved higher loading capacity (LC) and entrapment efficiency (EE) for the encapsulated OVA. An in vitro oral release profile showed that the OVA-Lipid NPs were with lower initial burst and could protect the loaded OVA from the harsh gastrointestinal (GI) environment for a long time. In addition, a human microfold cell (M-cell) transcytotic assay demonstrated that due to a lipid layer structure on the particle surface, the Lipid NPs showed higher affinity to the M-cells. Since the M-cell in the intestinal epithelium played an important role in particle transportation as well as intimately associated with the underlying immune cells, the OVA-Lipid NPs effectively induced mucosal and humoral immune responses
Research on the Effect of Burial Depth on The Bearing Characteristics of Three Helical Piles Jacket Foundation for Offshore Wind Turbines
With global offshore wind power gradually moving to deep and distant waters, there is a clear trend towards larger-scale units, posing significant challenges for future offshore wind power foundations. In this paper, a helical pile jacket foundation type is proposed by combining the advantages of the current jacket foundation, which is suitable for deep and distant seas and offers high stiffness, with the excellent bearing performance of helical pile foundations. The influence of buried depth on the bearing characteristics of this foundation type is discussed through a physical model test. The results obtained from the study reveal the distinct bearing characteristics and damage modes exhibited by the foundation under deep and shallow burial conditions. These findings clearly indicate that the overall bearing characteristics and damage modes are superior in deep burial conditions compared to shallow burial conditions. Furthermore, it is observed that the damage and displacement of the foundation are more concentrated in localized areas when subjected to shallow burial
Uniform-sized PLGA-HSPC lipospheres as a biocompatible platform for controlled release of proteins and peptides
Int. J. Pharm.
Oral delivery of antigens is patient-friendly and efficient way of treating intestinal infections. However, the efficacy of oral vaccines is limited by degradation in the gastrointestinal (GI) tract and poor absorption by enterocytes and antigen-presenting cells (APC). Here we report ulex europaeus agglutinin-1 (UEA-1) conjugated poly (D,L-lactide-co-glycolide) (PLGA)-lipid nanoparticles (NP) containing a Toll-like receptor (TLR)-agonist monophosphoryl lipid A (MPL) as an oral vaccine delivery system. The uniform-sized PLGA-lipid NPs (simplified as lipid NPs) were produced by the premix membrane emulsification method. They can protect the entrapped model antigen ovalbumin (OVA) from exposure to the GI tract and release the OVA in a controlled manner. With UEA-1 and MPL modification, the UEA-MPL/lipid NPs can be effectively transported by M-cells and captured by mucosal dendritic cells (DCs). After in vivo vaccination, the OVA-UEA-MPL/lipid NPs stimulated the most effective mucosal IgA and serum IgG antibodies during the oral formulations. These results suggest that this MPL containing M-cell targeted lipid NP can potentially be used as a universally robust oral vaccine delivery system. (C) 2014 Elsevier B.V. All rights reserved.Oral delivery of antigens is patient-friendly and efficient way of treating intestinal infections. However, the efficacy of oral vaccines is limited by degradation in the gastrointestinal (GI) tract and poor absorption by enterocytes and antigen-presenting cells (APC). Here we report ulex europaeus agglutinin-1 (UEA-1) conjugated poly (D,L-lactide-co-glycolide) (PLGA)-lipid nanoparticles (NP) containing a Toll-like receptor (TLR)-agonist monophosphoryl lipid A (MPL) as an oral vaccine delivery system. The uniform-sized PLGA-lipid NPs (simplified as lipid NPs) were produced by the premix membrane emulsification method. They can protect the entrapped model antigen ovalbumin (OVA) from exposure to the GI tract and release the OVA in a controlled manner. With UEA-1 and MPL modification, the UEA-MPL/lipid NPs can be effectively transported by M-cells and captured by mucosal dendritic cells (DCs). After in vivo vaccination, the OVA-UEA-MPL/lipid NPs stimulated the most effective mucosal IgA and serum IgG antibodies during the oral formulations. These results suggest that this MPL containing M-cell targeted lipid NP can potentially be used as a universally robust oral vaccine delivery system. (C) 2014 Elsevier B.V. All rights reserved
Short-Term Load Forecasting for Industrial Enterprises Based on Long Short-Term Memory Network
In China, industrial enterprises develop rapidly, and industrial electricity consumption account for 70% of social electricity consumption. However, the charging mode of industrial electricity is very complicated which can be divided into two basic modes, one mode is to pay according to transformer capacity and other mode is to pay according to maximum demand. In both modes, the complex charging type involving seasonal factors and national economic growth. Once a company chooses the wrong mode to buy electricity, it has to change it three months later. In this case, it not only increases the cost of electricity but also wastes resources. Therefore, it is important to predict the future load data according to the energy consumption characteristics of enterprises. In the context of big data, the electricity data of Chinese enterprises will be developed and utilized gradually. In this paper, the long short-term memory (LSTM) model is built to carry out load forecasting of the international dairy companies which called Ausnutria. The simulation results show that LSTM network is feasible in the field of load prediction, and the method can ensure the accuracy
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