47 research outputs found
Multi-mode-driven molecular shuttles photochemically and chemically reactive benzoxazole-containing rotaxanes
Co-expression of apoptin (VP3) and antibacterial peptide cecropin B mutant (ABPS1) genes induce higher rate of apoptosis in HepG2 and A375 cell lines
The antibacterial peptide cecropin B mutant (ABPS1) gene has a broad range of antibacterial and antiproliferative properties. Apoptin (VP3), a chicken anaemia virus-encoded protein is known to induce apoptosis in human transformed cells. To explore drug combination in human tumor cells, apoptin and ABPS1 eukaryotic expression vector pIRES2-EGFP-apoptin and pIRES2-EGFP-ABPS1 were constructed and their expression effect individually and in combinations were studied in HepG2 and A375 cells. The vector pIRES2-EGFP-ABPS1 and pIRES2-EGFP-apoptin were transfected into tumor cells HepG2 and A375 by the lipofectamine-mediated DNA transfection procedure. At 48 h post transfection, the apoptotic rate obtained by flow cytometry and the morphological changes under light and scanning electron microscope of tumor cells were significant. In contrast, the microvilli on the surface of the control cells were disrupted, decreased and even disappeared. The cell membrane was injured and intracellular substances leaked out. Furthermore, our results indicate that the apoptotic rates of apoptin (27.32% in HepG2 and 9.34% in A375 cells), were higher than ABPS1 (23.79% in HepG2 and 8.33% in A375 cells). Moreover, the co-expression of Apoptin and ABPS1 showed higher apoptotic rates which were 27.66 and 10.33% in HepG2 and A375 cells respectively. However, the apoptotic rates obtained in HepG2 cells treated with apoptin and apoptin and ABPS1 together were closely similar, but, not in A375 cells. Therefore, the results of the present study showed that the combination of Apoptin and ABPS1 has synergistic effect in HepG2 and A375 cell lines.Keys words: Apoptin, ABPS1, apoptosis, co-expression, HepG2, A375
Hidden species diversity in Pachyhynobius: a multiple approaches species delimitation with mitogenomes
The lack of distinct morphological features of cryptic species is a hard problem for taxonomy, especially when the taxa are closely related with considerable amounts of ancestral polymorphism. Lately, intensive coalescent-based analyses involving multiple loci have become the preferred method to assess the extent of genetic distinctiveness in otherwise phenotypically similar populations. Previously, phylogenetic studies on Pachyhynobius shangchengensis uncovered five extremely deeply divergent clades, which suggested that this species may be a cryptic species complex. In this study, we used the complete mitochondrial genome data and samples from the entire range of stout salamander (Pachyhynobius), as well as publicly available mitochondrial genomes to assess species boundaries within this genus using a suite of diverse methodologies (e.g. general mixed Yule coalescent model, Automatic Barcode Gap Discovery). The phylogenetic relationships recovered two major groups within P. shangchengensis, with one group formed by four of the six extant populations and corresponding to the central and eastern range of the Dabie mountains, while the other group encompassed two other lineages in the north west of the Dabie mountain range. The species delimitation comparison within Pachyhynobius supported the presence of recognized species within the genus, and consensus was observed across methods for the existence of up to five cryptic species within what has been traditionally considered to be P. shangchengensis. While this implies the existence of four taxa in addition to the described P. shangchengensis species, morphological data and life history information are further required to contribute to the species definition. The observed pattern of genetic variation is likely the outcome of a discontinuous habitat combined with niche conservatism, which produced the sky-island effect observed in Pachyhynobius, and which led to formation of a hidden species diversity in this genus
TencentPretrain: A Scalable and Flexible Toolkit for Pre-training Models of Different Modalities
Recently, the success of pre-training in text domain has been fully extended
to vision, audio, and cross-modal scenarios. The proposed pre-training models
of different modalities are showing a rising trend of homogeneity in their
model structures, which brings the opportunity to implement different
pre-training models within a uniform framework. In this paper, we present
TencentPretrain, a toolkit supporting pre-training models of different
modalities. The core feature of TencentPretrain is the modular design. The
toolkit uniformly divides pre-training models into 5 components: embedding,
encoder, target embedding, decoder, and target. As almost all of common modules
are provided in each component, users can choose the desired modules from
different components to build a complete pre-training model. The modular design
enables users to efficiently reproduce existing pre-training models or build
brand-new one. We test the toolkit on text, vision, and audio benchmarks and
show that it can match the performance of the original implementations
Fuzzy investment portfolio selection models based on interval analysis approach
This paper employs fuzzy set theory to solve the unintuitive problem of the Markowitz mean-variance (MV) portfolio model and extend it to a fuzzy investment portfolio selection model. Our model establishes intervals for expected returns and risk preference, which can take into account investors' different investment appetite and thus can find the optimal resolution for each interval. In the empirical part, we test this model in Chinese stocks investment and find that this model can fulfill different kinds of investors' objectives. Finally, investment risk can be decreased when we add investment limit to each stock in the portfolio, which indicates our model is useful in practice
Hydrothermal Synthesis of Modified Hydrophobic Zn–Al-Layered Double Hydroxides Using Structure-Directing Agents and Their Enhanced Adsorption Capacity for -Nitrophenol
Hollow microspheres of hierarchical ZnAl-layered double hydroxides (LDHs) were synthesized by a simple hydrothermal method using hexamethylenetetramine as precipitating agent, sodium dodecyl benzene sulphonate (SDBS) as surfactant and sodium tartrate, sodium citrate and sodium salicylate (SS) as structure-directing agents, respectively. Characterization results of the microspheres synthesized indicate that the modified ZnAl–LDHs formed a variety of morphologies, surface areas and pore volumes. The hierarchical porous ZnAl/SDBS–LDH prepared using SS possesses the highest surface area (128.9 m 2 /g) and the greatest pore volume (0.37 cm 3 /g). A possible formation mechanism of the special three-dimensional nanostructures from the primary LDH nanosheet building units is proposed on the basis of the interaction between SS molecules and LDH crystals. The size of the channel height is approximately equal to the diameter of the intercalated anion SDBS, indicating that SDBS is in a vertical single-layer arrangement. using p -nitrophenol as model pollutant, the effects of initial concentration of p -nitrophenol and contact time on the adsorption of p -nitrophenol using various ZnAl–LDHs were investigated by performing a series of experiments. Results of these experiments indicate that the microsphere hydrophobic ZnAl/SDBS–LDH modified using SS has a maximum p -nitrophenol adsorption capacity of 101.6 mg/g
A highly integrated CMOS image sensor architecture for low voltage applications with deep submicron process
In this paper, a design methodology to fabricate a CMOS imaging system in an ultra-low voltage environment with a deep submicron process is presented. The new design methodology is based on a rail-to-rail pixel architecture together with a high dynamic range single-slope analog-to-digital converter (ADC). Correlated doubling sampling (CDS) is built-in in the readout system to suppress both fix pattern noise and kTC noise. An imaging test chip has been fabricated with a TSMC 0.25μm CMOS process and proved to function at a supply voltage of 1V or below. Two operation modes are also implemented to tradeoff between high speed and low power operations
Solvent-free Route to High-performance Electrode Materials for Li/Na Storage from Mechanochemically Synthetised MOFs/MXene Composites
The development of new energy-related materials is the pinnacle to attaining a sustainable society based on renewable energy. Over the past decades, plenty of electrode materials have been investigated seeking better energy storage properties. However, the often tedious synthetic procedures and large amounts of solvents utilized during their syntheses incur in high costs and severe environmental pollution. Here we present a solvent-free approach to metal-organic-frameworks/MXene-derived carbonaceous metal selenide/MXene composites with unique nanostructures rich in mesopores and macropores. These species can be readily transformed into high-performance electrode materials with enhanced Li/Na ion storage properties compared with their solution-based counterparts. Our results provide an environmentally benign production process of metal-organic framework/MXene-derived high-performance electrode materials for advanced lithium/sodium storage application
Ramie Biomass Derived Nitrogen-Doped Activated Carbon for Efficient Electrocatalytic Production of Hydrogen Peroxide
Ramie is a typical low-cost and sustainable natural biomass resource in China. In this study, we fabricated nitrogen-doped activated carbon with high surface area from ramie biomass as a highly efficient electrocatalyst for hydrogen peroxide production. Electrochemical characterizations revealed that the as-prepared catalyst showed superior oxygen reduction reaction activity through a two-electron pathway and extraordinary long-term stability. The current density and onset potential of AC700 was greater than that of other as-prepared samples. The nitrogen atoms on the catalyst surface was derived from the biomass and deconvoluted by XPS techniques, which is beneficial for the enhancement of electrocatalytic performance. The present work furthers the development of biomass-derived carbon material for environmental applications. (C) 2018 The Electrochemical Society.</p
W-doped MoS2 nanosheets as a highly-efficient catalyst for hydrogen peroxide electroreduction in alkaline media
Novel W-doped MoS2 electrocatalysts have been successfully fabricated through a facile one-pot solvothermal method and employed for the hydrogen peroxide reduction reaction ( HPRR) in emerging alkaline H2O2-based fuel cells. The wide composition stoichiometry of W-doped MoS2 is obtained in molar fractions of 30% and 15%. It has been found that 30% W-doped MoS2 presents superior catalytic activity with a high peak current density of 2.83 mA cm(-2) at -0.86 V vs. Hg/HgO, owing to the heteroatom doping and the defect sites that emerged in the nanostructure. Furthermore, the influence of alkali concentration, H2O2 concentration and temperature on the HPRR is systematically investigated. The mechanism of HPRR is illustrated using a rotating disk electrode as a direct two-electron electroreduction pathway. Thereby, a new insight into heteroatom doping in transition metal dichalcogenides for HPRR applications is provided.</p