Inhibition of HDAC activity directly reprograms murine embryonic stem cells to trophoblast stem cells

Embryonic stem cells (ESCs) can differentiate into all cell types of the embryonic germ layers. ESCs can also generate totipotent 2C-like cells and trophectodermal cells. However, these latter transitions occur at low frequency due to epigenetic barriers, the nature of which is not fully understood. Here, we show that treating mouse ESCs with sodium butyrate (NaB) increases the population of 2C-like cells and enables direct reprogramming of ESCs into trophoblast stem cells (TSCs) without a transition through a 2C-like state. Mechanistically, NaB inhibits histone deacetylase activities in the LSD1-HDAC1/2 corepressor complex. This increases acetylation levels in the regulatory regions of both 2C- and TSC-specific genes, promoting their expression. In addition, NaB-treated cells acquire the capacity to generate blastocyst-like structures that can develop beyond the implantation stage in vitro and form deciduae in vivo. These results identify how epigenetics restrict the totipotent and trophectoderm fate in mouse ESCs.</p

Formability, Microstructure and Properties of Inconel 718 Superalloy Fabricated by Selective Laser Melting Additive Manufacture Technology

Many urgently needed inconel superalloy parts with complex internal cavity geometry and high surface precision are difficult to prepare by traditional subtractive manufacturing methods because of its poor machinability. The additive manufacturing technology that has emerged in recent years became a research hotspot in the manufacture of refractory and difficult-to-process metals. In the present study, selective laser melting (SLM), a typical additive manufacture technology, was used to prepare Inconel 718 samples. The influences of input laser energy density ((E, J/mm3) on densification behavior, phases composition, microstructures, microhardness, and wear performance of the SLM as-built Inconel 718 samples were explored in detail. X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to examine the phase composition and microstructure evolutions. The results show that the formablity, microstructures and mechanical properties of the printed samples were all improved with the increase of E within the parameter setting range of this study. At a lower E, the poor surface morphology and balling effect occurred, the density, hardness, and wear resistance were all at a relatively lower level. When an E value of 190 J/mm was properly set, the surface open-pores and balling effect disappeared, the laser scanning tracks became smooth and continuous, the near-full dense (99.15%) and specimens with good metallurgical bonding and no critical defect were obtained, in which the average microhardness value reached 348 HV0.2 and wear rate was 5.67 × 10−4 mm3/N·m. The homogeneity of the superalloy Inconel 718 was also explored

Direct Purification of Digestate Using Polymeric Ultrafiltration Membranes: Influence of Materials on Filtration Behavior and Fouling Characteristics

In-depth exploration of filtration behavior and fouling characteristics of polymeric ultrafiltration (UF) membranes can provide guidance for the selection of materials and the control of membrane fouling during the purification of digestate. In this study, four types of polymeric membranes, (polyethersulfone (PES), polysulfone (PS), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN)), were employed to filter digestate from swine manure. The results showed that the viscosity of the digestate dropped from 45.0 ± 11.3 mPa·s to 18.0 ± 9.8 mPa·s, with an increase in temperature from 30.0 °C to 45.0 °C. The four membrane fluxes all increased by more than 30%, with the cross flow velocity increasing from 1.0 m s−1 to 2.0 m s−1. During the batch experiments, the flux maintenance abilities of the membranes were in the order: PAN > PS > PVDF > PES. There were no significant differences in the effects of membrane materials on the removal of COD, TN, and TP (p 254 removal efficiency, PS showed the highest efficiency (68.6%), while PVDF showed the lowest efficiency (63.4%). The major fouling type was irreversible hydraulic fouling, and the main elements of scaling were C, O, S, and Ca. Pseudomonadales were the dominant bacteria in the PS (26.2%) and in the PVDF (51.4%) fouling layers, while Bacteroidales were the dominant bacteria in the PES (26.8%) and in the PAN (14.7%) fouling layers. The flux recovery rates (FRRs) of the cleaning methods can be arranged as follows: NaClO > NaOH > Citric acid ≈ Tap water. After NaClO cleaning, the PVDF membrance showed the highest FRR (73.1%), and the PAN membrane showed the lowest FRR (30.1%)

PaperNet: A Dataset and Benchmark for Fine-Grained Paper Classification

Document classification is an important area in Natural Language Processing (NLP). Because a huge amount of scientific papers have been published at an accelerating rate, it is beneficial to carry out intelligent paper classifications, especially fine-grained classification for researchers. However, a public scientific paper dataset for fine-grained classification is still lacking, so the existing document classification methods have not been put to the test. To fill this vacancy, we designed and collected the PaperNet-Dataset that consists of multi-modal data (texts and figures). PaperNet 1.0 version contains hierarchical categories of papers in the fields of computer vision (CV) and NLP, 2 coarse-grained and 20 fine-grained (7 in CV and 13 in NLP). We ran current mainstream models on the PaperNet-Dataset, along with a multi-modal method that we propose. Interestingly, none of these methods reaches an accuracy of 80% in fine-grained classification, showing plenty of room for improvement. We hope that PaperNet-Dataset will inspire more work in this challenging area

Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer

Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction. It is found that the densities of screw an

Fully printed memristors made with MoS2 and graphene water-based inks

2-Dimensional Materials (2DMs) offer an attractive solution for the realization of high density and reliable memristors, compatible with printed and flexible electronics. In this work we fabricate a fully inkjet printed MoS2-based resistive switching memory, where graphene is used as top electrode and silver is used as bottom electrode. Memristic effects are observed only after annealing of each printed component. The printed memory on silicon shows low SET/RESET voltage, short switching times (less than 0.1 s) and resistance switching ratios of 103-105, superior to the performance obtained in devices with both printed silver electrodes on rigid substrates. The same device on Kapton shows resistance switching ratios of 102-103 and remains stable at least up to 2% strain. The memristor resistance switching is attributed to the formation of Ag conductive filaments, which can be suppressed by integrating graphene grown by chemical vapour deposition (CVD) onto the silver electrode. Temperature-dependent electrical measurements starting from 200 K show that memristic behavior appears at temperature of ~300 K, confirming that an energy threshold is needed to form the conductive filament. This work shows that inkjet printing is a very powerful technique for the fabrication of 2DMs-based resistive switches onto rigid and flexible substrates