ISRIB facilitates the co-culture of human trophoblast stem cells and embryonic stem cells.

The embryo-like structures (embryoids) constructed by aggregating embryonic stem cells (ESCs) and trophoblast stem cells (TSCs) have provided revolutionary tools for studying the intricate interaction between embryonic and extra-embryonic tissues during early embryonic development, which has been achieved in mice. However, due to the opposite dependence on some signalling pathways for in vitro culture of human ESCs (hESCs) and TSCs (hTSCs), particularly WNT and TGFß signalling pathways, which limits the construction of human post-implantation embryoids by aggregating hESCs and hTSCs. To overcome this challenge, here, by screening 1639 chemicals, we found that an inhibitor of integrated stress response, ISRIB, can replace WNT agonists and TGFß inhibitors to maintain the stemness and differentiation capacity of hTSCs. Thus, we developed an ISRIB-dependent in vitro culture medium for hTSCs, namely nTSM. Furthermore, we demonstrated that ISRIB could also maintain the hESC stemness. Using a 3D co-culture system (hESCs and hTSCs aggregate, ETA), we demonstrated that a 1:1 mixture of hESC culture medium (ESM) and nTSM improved the cell proliferation and organisation of both hESC- and hTSC-compartments and the lumenogenesis of hESC-compartment in ETAs. Overall, our study provided an ISRIB-dependent system for co-culturing hESCs and hTSCs, which facilitated the construction of human embryoids by aggregating hESCs and hTSCs.

Preparation of magnetic sodium alginate/sodium carboxymethylcellulose interpenetrating network gel spheres and use in superefficient adsorption of direct dyes in water.

The rapid development of the printing and dyeing industry has led to the production of a large amount of high-density printing and dyeing wastewater, and technology for its effective treatment has become a focus of research. To construct a polymeric adsorbent material with abundant functional groups for the efficient adsorption of dye wastewater, a novel magnetic sodium alginate/carboxymethylcellulose interpenetrating network gel sphere (Fe3O4@SA/CMC-Fe) was prepared by co-blending sodium alginate (SA) and sodium carboxymethylcellulose (CMC) with Fe3O4; Fe3O4@SA/CMC-Fe was characterized by SEM-EDS, XRD, TGA, FT-IR, UV-Vis, VSM, BET-BJH and XPS. Static adsorption experiments showed that the optimal rates for adsorption of DV 51 and DR 23 from solutions with neutral pH values by Fe3O4@SA/CMC-Fe were up to 96 %, the adsorption process exhibited a Langmuir adsorption isotherm, and the dynamic adsorption process was accurately described by the pseudo-second-order kinetic model. A thermodynamic study showed that the adsorption reactions were all spontaneous exothermic reactions with increasing entropy. The mechanism for adsorption of the dyes by Fe3O4@SA/CMC-Fe involved hydrogen bonding, complexation and electrostatic adsorption. In summary, Fe3O4@SA/CMC-Fe is a green, simple, recyclable and highly efficient magnetic adsorbent that is expected to be widely used in treating dye wastewaters over a wide pH range.

Rational design of periodic porous titanium nitride MXene as a multifunctional catalytic membrane.

Inspired by the experimental realization of lattice-porous graphene and mesoporous MXenes, the possibility of lattice-penetrated porous titanium nitride, Ti12N8, was proposed and verified by density functional theory calculations. Stabilities, together with mechanical and electronic characteristics, are investigated and systemically discussed: both pristine and terminated (-O, -F, -OH) Ti12N8 show great thermodynamic and kinetic stabilities; the reduced stiffness introduced by lattice pores makes Ti12N8 better candidates for functional heterojunctions with less lattice mismatch. Subnanometer-sized pores increased the number of potential catalytic adsorption sites, and terminations allowed the band gap of MXene to reach 2.25 eV. Moreover, by changing terminations and introducing lattice channels, Ti12N8 could be expected to be used for different applications: direct photocatalytic water splitting, excellent H2/CH4 and He/CH4 selectivity and admirable HER/CO2RR overpotentials. Such excellent characteristics could provide another possible path for flexible nanodevices with tunable mechanics, electronics and optoelectronics properties.

Identifying a dynamic transcriptomic landscape of the cynomolgus macaque placenta during pregnancy at single-cell resolution.

Supporting healthy pregnancy outcomes requires a comprehensive understanding of the cellular hierarchy and underlying molecular mechanisms in the primate placenta during gestation. Here, we present a single-cell transcriptome-wide view of the cynomolgus macaque placenta throughout gestation. Bioinformatics analyses and multiple validation experiments suggested that placental trophoblast cells exhibited stage-specific differences across gestation. Interactions between trophoblast cells and decidual cells also showed gestational stage-dependent differences. The trajectories of the villous core cells indicated that placental mesenchymal cells were derived from extraembryonic mesoderm (ExE.Meso) 1, whereas placental Hofbauer cells, erythrocytes, and endothelial cells were derived from ExE.Meso2. Comparative analyses of human and macaque placentas uncovered conserved features of placentation across species, and the discrepancies of extravillous trophoblast cells (EVTs) between human and macaque correlated to their differences in invasion patterns and maternal-fetal interactions. Our study provides a groundwork for elucidating the cellular basis of primate placentation.

VMP1 affects endoplasmic reticulum stress sensitivity via differential modulation of the three unfolded protein response arms.

Consisting of three signaling pathways, the unfolded protein response (UPR) can be either protective or detrimental to cells that undergo ER stress. Elaborate regulation of the UPR is key to the cell-fate decision, but how it is achieved remains vague. Here, by studying cells deficient in vacuole membrane protein 1 (VMP1), a UPR regulator, we report a model of UPR regulation in which the three pathways are divergently controlled. Under basal conditions, calcium binding specifically activates PERK. Under ER stress, ER-mitochondria interaction-induced mitochondrial stress cooperates with PERK to suppress IRE1α and ATF6 by decelerating global protein synthesis. Such sophisticated regulation commits limited activation of the UPR yet refrains from UPR hyperactivation, protecting cells from chronic ER stress despite decreasing cell proliferation. Therefore, our study reveals interorganelle-interaction-dependent and calcium-dependent regulation of the UPR that dictates cell fate.

Theoretical study on an oxygen-modified phosphorene autogenous Z-scheme heterojunction for hydrogen evolution.

We propose a novel strategy for the construction of Z-scheme heterojunction photocatalyst based on in situ chemical modification and autogenous black phosphorus nanosheets. Such heterostructures have negligible lattice mismatch ratio and fast electron transfer rate, which would provide a highly universal and efficient design and synthesis strategy with guiding significance for Z-scheme heterojunctions.

Electrospun nanofibrous poly(ether-block-amide) membrane for removing biogenic amines in acidic wastewater from the yellow rice wine factory.

Compared with other techniques for wastewater treatment, adsorption offers an effective, economical and ecofriendly way to reduce the content of biogenic amines. Herein, the poly(ether-block-amide) (PEBA 2533) membranes were employed as the adsorbent to remove histamine, putrescine, cadaverine and tyramine in the synthetic and real wastewater from a local yellow rice wine factory. Electrospun PEBA membranes consisting of fine nanofibers were successfully obtained without the addition of surfactant for the first time. Characteristics of the prepared membranes were evaluated by their morphology, wetting behaviors and mechanical properties. Adsorption performance of the nanofibrous membrane was investigated in comparison to the dense membrane prepared by conventional casting. The fibrous membrane exhibited much higher adsorption rate over 10 times to the dense membrane along with 1.5 times more adsorption capacity towards the amines. In addition, the as-prepared membrane showed a promising reusability in the real wastewater treatment. The good balance of its chemical stability, adsorption capacity, selectivity, removal efficiency and reusability endows the electrospun membrane with an outstanding potential to be applied in the acidic wastewater treatment for the yellow rice wine industry.

Preparation of polyethersulfone/magnesium silicate membranes via casting and electrospinning and their application in the removal of free fatty acids from biodiesel.

Due to the reversible nature of reactions in biodiesel production, a purification process is necessary for the biodiesel to meet international standards. As an effective method, dry washing has been applied in biodiesel purification for years, but it still faces limitations and challenges. In this work, a magnesium silicate (MS) was synthesized using the hydrothermal method. Two types of composite membranes were prepared by doping the prepared magnesium silicate into polyethersulfone (PES) via casting and electrospinning, respectively. Structural and physical properties of the composite membranes were characterized. The composite membranes were applied as adsorbents to remove free fatty acids (FFAs) from crude biodiesel. Adsorption isotherm and kinetic studies were performed at different temperatures (20, 40 and 60 °C). For both membranes, the obtained adsorption capacity was higher at low temperature (20 °C). Maximum adsorption capacity was found with the electrospun membrane to be 852 mg g-1, calculated from the Langmuir model. Adsorption kinetics for both membranes can be well described using the pseudo-second-order model. In addition, the internal diffusion was not negligible during the adsorption process based on the intraparticle diffusion analysis. As revealed by thermodynamic study, the adsorption processes were all exothermic with a spontaneous nature. Reusability of the membrane adsorbents was evaluated, in which the electrospun membrane showed a promising performance with 94% adsorption capacity remaining over 8 cycles of adsorption and desorption.

Revealing the mechanisms of mercury adsorption on metal-doped kaolinite(001) surfaces by first principles.

Natural kaolinite exhibit high affinity for heavy metals while the interaction mechanisms in the presence of heteroatoms remain largely elusive, which are tackled by first principles. In this paper, three common dopants (Mg, Ca, Fe) were employed to construct metal-doped kaolinite(001) (K(001)) surfaces. We found that Mg-doped K(001) was the most stable surface in terms of thermal stability and structural analysis, consistent with the pervasive isomorphic substitution in kaolinite minerals. The interaction of mercury with Mg-doped K(001) surface was investigated in the form of predominant top-site and bridge-site models. The effects of chloride on the interaction were also studied. The results demonstrated that the strongest adsorption occured in the present of dopants and the absence of chloride. The electronic properties revealed a significant charge transfer (up to 1.28 electrons) and chemisorption character at the interfaces when dopants were introduced, which could be ascribed to the overlapping of Hg-5d and Os-2p (surface O) orbitals in the range of -7.5 eV to +0.5 eV. Additionally, the chloride had a profoundly adverse influence on mercury adsorption due to the upward shift of Hg-6s and Hg-6p orbitals. The studies are beneficial to understand the interaction mechanisms of natural minerals toward environmental pollutants in actual applications.

Theoretical insights into the adsorption mechanism of Cd(II) on the basal surfaces of kaolinite.

Retardation of Cd(II) migration is an ongoing concern for environmental remediation, but a prevalent obstacle of the procedure originates from the lack of an atomic-scale description of the inherent mechanism for Cd(II) adsorption at mineral-water interfaces. Herein, we performed first-principles calculations and ab initio molecular dynamics (AIMD) simulations to explore the adsorption mechanism of Cd(II) on the basal surfaces of kaolinite. Representative monodentate and bidentate Cd(II) complexes were constructed on the Kln-Al(001) and Kln-Si(001̅) surfaces. The results showed that bidentate coordination of Cd(II) on the Kln-Al(001) surface was superior to all other studied models due to the favorable formation energy and better agreement with EXAFS data. The calculated electron density difference revealed the charge transfer from surface oxygen (Os) to Cd(II) upon adsorption. In particular, partial density of states (PDOS) analysis indicated that the Cd-Os bond exhibited covalent characteristics, attributed to the overlaps of Cd-5p and Os-2p orbitals in the valence band. Furthermore, radial distribution functions supported by AIMD simulations were employed to confirm the structural features of Cd(II) coordination shell at kaolinite-water interfaces. This theoretical study provides insightful guidance for future Cd(II) research to improve current assessments of contaminant remediation.

Synthesis of luminescent cocrystals based on fluoranthene and the analysis of weak interactions and photophysical properties.

A series of luminescent cocrystals with fluoranthene (C16H10) as the fluorophore and benzene-1,2,4,5-tetracarbonitrile (TCNB, C10H2N4), 2,3,5,6-tetrafluorobenzene-1,4-dicarbonitrile (TFP, C8F4N2) and 1,2,3,4,5,6,7,8-octafluoronaphthalene (OFN, C10F8) as the coformers was designed and synthesized. Structure analysis revealed that these layered structures were due to charge transfer, π-π interactions and hydrogen bonding. Density functional theory (DFT) calculations show that fluoranthene-TCNB and fluoranthene-TFP have charge-transfer properties, while fluoranthene-OFN does not, indicating that fluoranthene-OFN has arene-perfluoroarene (AP) interactions, which was also demonstrated by spectroscopic analysis, which shows that the photophysical properties of luminescent materials can be tuned by forming cocrystals. These results all prove that utilizing supramolecular cocrystals to develop new fluorescent materials is an effective strategy, which has much potential in optoelectronic applications.

The tesseract in two dimensional materials, a DFT approach.

A series of novel two-dimensional materials inspired from a 4D polytope, tesseract, have been proposed by density functional theory (DFT) based computations. Both C24X12 and C16X16 (X = O, S and Se) are found to have great thermodynamic and dynamic stabilities, and C24X12 exhibited excellent thermal stability up to 1000 K. All these 2D crystals are semiconductors with 2.17 eV to 3.35 eV band gaps at the HSE06 theoretical level, except for C24S12 (4.14 eV energy gap). Moreover, the intrinsic pore sizes of C24Se12 are suitable to sieve He from the He/CH4 mixture, with over 80% separation ratio and nearly 100% selectivity. Our findings not only enlarged the boundary of the 2D family, but also offered another potential method to recover helium from natural gas at ambient conditions.

Combining bioactivity and affinity to design of positive allosteric modulators of the metabotropic glutamate receptor using 3D-QSAR.

Communicated by Ramaswamy H. Sarma.

Multicomponent supramolecular assemblies of 1(2H)-Phthalazinone and Tetrafluoroterephthalic acid: Understanding the role of hydrogen bonding on the structure and properties using experimental and computational analyses.

Two novel cocrystals were successfully constructed by 1(2H)-Phthalazinone (PHT) and Tetrafluoroterephthalic acid (TETA) based on O-H⋯O, N-H⋯O, C-H⋯O, C-H⋯F, N-H⋯N and C-H⋯N hydrogen bonding networks, and were well depicted by single crystal diffraction analysis. As predicted by electrostatic potential analysis, the stoichiometry of PHT to TETA is 2:1 and stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The single crystal X-ray diffraction characterized that the two cocrystals were all made up by 2PHT-TETA motif in different ways. AIM analysis and Hirshfeld surfaces indicated the adjacent 2PHT-TETA units assemble through C-H⋯O, C-H⋯F and C-H⋯N hydrogen bonds, producing a 2D plane structure in cocrystal I. Meanwhile, the C-H⋯F, N-H⋯N and C-H⋯O hydrogen bonds between 2PHT-TETA units were the stabilizing factors in cocrystal II. Topological parameters such as ∇2ρ and H revealed the strength of hydrogen bonds were moderate in nature except O31⋯H32-O34 (1.704Å, -60.336kJmol-1) in compound I. The hydrogen bonding interactions, cocrystal stability and electron donor-acceptor interactions were investigated using natural bonding orbital analysis. It showed that electron transfer of n(O) σ*(O-H) and n(O) σ*(N-H) between PHT and TETA influence the packing characteristics significantly. Structural changes accompanying cocrystal process have been rationalized through the IR spectrum along with the quantum chemical calculations. The frequency downshifts of CO, N-H and O-H stretching after cocrystallization have been attributed to hydrogen bonding interactions.

New insights into the surface plasmon resonance (SPR) driven photocatalytic H2 production of Au-TiO2.

The Surface Plasmon Resonance (SPR) driven photocatalytic H2 production upon visible light illumination (≥500 nm) was investigated on gold-loaded TiO2 (Au-TiO2). It has been clearly shown that the Au-SPR can directly lead to photocatalytic H2 evolution under illumination (≥500 nm). However, there are still some open issues about the underlying mechanism for the SPR-driven photocatalytic H2 production, especially the explanation of the resonance energy transfer (RET) theory and the direct electron transfer (DET) theory. In this contribution, by means of the EPR and laser flash photolysis spectroscopy, we clearly showed the signals for different species formed by trapped electrons and holes in TiO2 upon visible light illumination (≥500 nm). However, the energy of the Au-SPR is insufficient to overcome the bandgap of TiO2. The signals of the trapped electrons and holes originate from two distinct processes, rather than the simple electron-hole pair excitation. Results obtained by Laser Flash Photolysis spectroscopy evidenced that, due to the Au-SPR effect, Au NPs can inject electrons to the conduction band of TiO2 and the Au-SPR can also initiate e-/h+ pair generation (interfacial charge transfer process) upon visible light illumination (≥500 nm). Moreover, the Density Functional Theory (DFT) calculation provided direct evidence that, due to the Au-SPR, new impurity energy levels occurred, thus further theoretically elaborating the proposed mechanisms.

Liquid chromatography coupled to quadrupole-Orbitrap high resolution mass spectrometry based method for target analysis and suspect screening of non-ionic surfactants in textiles.

In this study, we describe a high-throughput and sensitive method for textiles analysis, using liquid chromatography coupled to quadrupole-Orbitrap high resolution mass spectrometry (LC-Q-Orbitrap HRMS), for the simultaneously quantitative analysis of 40 target alkylphenol polyethoxylates (APEO) oligomers with reference standards and screening of 160 alcohol polyethoxylates (AEO) oligomers without standards in textiles. The APEOs contain nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) with an EO number of ethylene oxide of 1-20, while AEOs focus on C11EOs-C18EOs with an EO number of 1-20. After ultrasonic extraction in methanol, the extract was directly separated using a core-shell CORTECS C18+ column and analyzed by Full MS/dd-MS2 (data dependent acquisition) scan in ESI positive mode. Two best sensitivity experimental conditions for APEOs with short EO chains (AP(EO)1-2) and long EO chains (AP(EO)3-20) were investigated, respectively. Most APEO oligomers had wide concentration ranges and the correlation coefficients (R2) were higher than 0.999. The limit of quantitation (LOQ) values for NP(EO)3-20 oligomers ranges from 16.00 to 52.80µg/kg and for OP(EO)3-20 oligomers is from 2.40 to 8.00µg/kg. LOQ for NP(EO)1 and NP(EO)2, OP(EO)1 and OP(EO)2 was 2.40mg/kg and 0.24mg/kg, 1.20mg/kg and 0.16mg/kg, respectively. The average recovery for each APEO oligomer in cotton and polyester matrix was between 78% and 110% at three spiked levels and the relative standard deviation (RSD%) was below 10%. As to AEOs suspects, a HRMS compound database containing 160 AEO oligomers was built and several parameters such as exact m/z, isotopic patterns, predicted product ions and predicted retention time were used for screening and confirmation. The established method was successfully applied for analysis of 40 commercial textile samples. Compared with OPEOs, NPEOs, especially NP(EO)3-15 oligomers, were widely detected in samples and the total concentration ranged from 1.56 to 1376.31mg/kg. AEOs were also found in most samples, among which C12-14, C16 and C18 compounds appeared more frequently and the EO chains mainly ranged from 3 to 15.

Layer-by-Layer Proteomic Analysis of Mytilus galloprovincialis Shell.

Bivalve shell is a biomineralized tissue with various layers/microstructures and excellent mechanical properties. Shell matrix proteins (SMPs) pervade and envelop the mineral crystals and play essential roles in biomineralization. Despite that Mytilus is an economically important bivalve, only few proteomic studies have been performed for the shell, and current knowledge of the SMP set responsible for different shell layers of Mytilus remains largely patchy. In this study, we observed that Mytilus galloprovincialis shell contained three layers, including nacre, fibrous prism, and myostracum that is involved in shell-muscle attachment. A parallel proteomic analysis was performed for these three layers. By combining LC-MS/MS analysis with Mytilus EST database interrogations, a whole set of 113 proteins was identified, and the distribution of these proteins in different shell layers followed a mosaic pattern. For each layer, about a half of identified proteins are unique and the others are shared by two or all of three layers. This is the first description of the protein set exclusive to nacre, myostracum, and fibrous prism in Mytilus shell. Moreover, most of identified proteins in the present study are novel SMPs, which greatly extended biomineralization-related protein data of Mytilus. These results are useful, on one hand, for understanding the roles of SMPs in the deposition of different shell layers. On the other hand, the identified protein set of myostracum provides candidates for further exploring the mechanism of adductor muscle-shell attachment.

Electrochemical activation of commercial polyacrylonitrile-based carbon fiber for the oxygen reduction reaction.

Nitrogen (N)-doped carbon and its non-noble metal composite replacing platinum-based oxygen reduction reaction (ORR) electrocatalysts still have some fundamental problems that remain. Here the micron-sized commercial polyacrylonitrile-based carbon fiber (PAN-CF) electrode was modified using an electrochemical method, converting its inherent pyridinic-N into 2-pyridone (or 2-hydroxyl pyridine) functional group existing in three-dimensional active layers with remarkable ORR catalytic activity and stability. The carbon atom adjacent to the nitrogen and oxygen atoms is prone to act as an active site to efficiently catalyze a two-electron ORR process. However, after coordinating pyridone to the Cu(2+) ion, together with the electrochemical reaction, the chemical redox between Cu(+) and ORR intermediates synergistically tends towards a four-electron pathway in alkaline solution. In different medium, the complexation and dissociation can induce the charge transfer and reconstruction among proton, metal ion and pyridone functionalities, eventually leading to the changes of ORR performance.