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Inspired by the research of BC 2 N and Si 2 BN monolayer, a new graphene-like AlNC 2 two-dimensional structure has been proposed, and the electronical properties and H 2 adsorption capability have been investigated by using density functional theory calculations. Three types of AlNC 2 structures are designed, only AlNC 2 type I and III are stable by calculating the phonon frequencies and ab intio molecular dynamics simulations. By calculating with HSE06 functional, the indirect band gap of AlNC 2 type I is 1.762 eV, and the direct band gap of AlNC 2 type III is 1.796 eV. The hydrogen gravimetric density of pure AlNC 2 type Ⅰ and Ⅲ can reach 5.84 wt% and 8.01 wt%, which corresponds to the average adsorption energy of −0.124 eV/H 2 and -0.109 eV/H 2 , respectively. [Display omitted] • A new graphene-like AlNC 2 two-dimensional structure has been proposed. • AlNC 2 type I and III are stable by calculating phonon spectrum and AIMD simulation. • The band gap of AlNC 2 type I and Ⅲ are 1.762 and 1.796 eV with HSE06 functional. • Hydrogen storage capacity of pure AlNC 2 type I and Ⅲ can reach 5.84 and 8.01 wt%. [ABSTRACT FROM AUTHOR]

Cytoskeleton protein 4.1 is an essential class of skeletal membrane protein, initially found in red blood cells, and can be classified into four types: 4.1R (red blood cell type), 4.1N (neuronal type), 4.1G (general type), and 4.1B (brain type). As research progressed, it was discovered that cytoskeleton protein 4.1 plays a vital role in cancer as a tumor suppressor. Many studies have also demonstrated that cytoskeleton protein 4.1 acts as a diagnostic and prognostic biomarker for tumors. Moreover, with the rise of immunotherapy, the tumor microenvironment as a treatment target in cancer has attracted great interest. Increasing evidence has shown the immunoregulatory potential of cytoskeleton protein 4.1 in the tumor microenvironment and treatment. In this review, we discuss the role of cytoskeleton protein 4.1 within the tumor microenvironment in immunoregulation and cancer development, with the intention of providing a new approach and new ideas for future cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]

In order to visualize the evolution process of impact damage inside carbon fiber-reinforced polymer (CFRP) laminates, the concept of impact damage reconstruction of CFRP laminates was proposed, and a background subtraction image segmentation method based on RGB color space was proposed to extract the damage of materials feature. First, infrared thermography was used to collect damage sequence images of CFRP laminates under different impact loads. The infrared sequence thermal images were prescreened, combined with weighted average fusion to obtain the fusion images and background images, and the background subtraction operation was performed to obtain the subtraction result image. The results of the group with the highest similarity were confirmed and based on this, the 3D reconstruction of the impact interlaminar damage of the laminate was constructed with the help of the 3D Volume of the IMAGE J software. [ABSTRACT FROM AUTHOR]

In infrared small target detection, the infrared patch image (IPI)-model-based methods produce better results than other popular approaches (such as max-mean, top-hat, and human visual system) but in some extreme cases it suffers from long processing times and inconsistent performance. In order to overcome these issues, we propose a novel approach of dividing the traditional target detection process into two steps: suppression of background noise and elimination of clutter. The workflow consists of four steps: after importing the images, the second step applies the alternating direction multiplier method to preliminarily remove the background. Comparatively to the IPI model, this step does not require sliding patches, resulting in a significant reduction in processing time. To eliminate residual noise and clutter, the interim results from morphological filtering are then processed in step 3 through an improved new top-hat transformation, using a threefold structuring element. The final step is thresholding segmentation, which uses an adaptive threshold algorithm. Compared with IPI and the new top-hat methods, as well as some other widely used methods, our approach was able to detect infrared targets more efficiently (90% less computational time) and consistently (no sudden performance drop). [ABSTRACT FROM AUTHOR]

Composite panel sandwiched by a perforated fiber reinforced damping film (CPSPFRDF) is a novel damping treatment structure. Compared with conventional damping sandwich composites, CPSPFRDF has higher stiffness under the large damping. A ring deformation model is proposed to characterize the misalignment of fibers. A multi‐scale mathematical model is established by means of the analytical method of cell structure. The equivalent elastic parameters of the perforated fiber reinforced damping film are obtained. The complex stiffness method is applied to build the dynamic model of the structure. The validity of the theoretical model is verified by experiments. The relationships of design parameters with the dynamic properties of CPSPFRDF are revealed further. This study will provide a reference for the design and manufacture of the composites with large damping and high stiffness. [ABSTRACT FROM AUTHOR]

The free vibration behaviors of the embedded and co-cured perforated damping sandwich composite (ECPDSC) in which the holes are filled with resin are investigated. The displacement field of laminated structure and the equivalent elastic parameters of the heterogeneous damping layer are presented by the combination of the first order shear deformation theory with homogenization method. The dynamic equations of the structure are derived on basis of the equivalent complex modulus theory, and the theoretical results are verified by experimental platform. The relationships of damping area ratio and the thickness of damping layer as well as the elastic modulus of viscoelastic material with the dynamic properties of ECPDSC are theoretically explored further. Results indicate that the modal frequency decreases slowly when the damping area ratio is relatively small, the modal frequency decreases rapidly when the damping area ratio is relatively large, and the trend of loss factor is just opposite. This investigation will lay a foundation for the design and manufacture of composite components with light weight, large damping as well as high stiffness. [ABSTRACT FROM AUTHOR]

Azacitidine is a DNA methyltransferase inhibitor that has been used as a singular agent for the treatment of myelodysplastic syndrome-refractory anemia with excess blast-1 and -2 (MDS-RAEB I/II). However, recurrence and overall response rates following this treatment remain unsatisfactory. The combination of azacitidine and venetoclax has been used for the clinical treatment of a variety of hematological diseases due to the synergistic killing effect of the two drugs. Venetoclax is a BCL-2 inhibitor that can inhibit mitochondrial metabolism. In addition, azacitidine has been shown to reduce the levels of myeloid cell leukemia 1 (MCL-1) in acute myeloid leukemia cells. MCL-1 is an anti-apoptotic protein and a potential source of resistance to venetoclax. However, the mechanism underlying the effects of combined venetoclax and azacitidine treatment remains to be fully elucidated. In the present study, the molecular mechanism underlying the impact of venetoclax on the efficacy of azacitidine was investigated by examining its effects on cell cycle progression. SKM-1 cell lines were treated in vitro with 0-2 µM venetoclax and 0-4 µM azacytidine. After 24, 48 and 72 h of treatment, the impact of the drugs on the cell cycle was assessed by flow cytometry. Following drug treatment, changes in cellular glutamine metabolism pathways was analyzed using western blotting (ATF4, CHOP, ASCT2, IDH2 and RB), quantitative PCR (ASCT2 and IDH2), liquid chromatography-mass spectrometry (α-KG, succinate and glutathione) and ELISA (glutamine and glutaminase). Venetoclax was found to inhibit mitochondrial activity though the alanine-serine-cysteine transporter 2 (ASCT2) pathway, which decreased glutamine uptake. Furthermore, venetoclax partially antagonized the action of azacitidine through this ASCT2 pathway, which was reversed by glutathione (GSH) treatment. These results suggest that GSH treatment can potentiate the synergistic therapeutic effects of venetoclax and azacitidine combined treatment on a myelodysplastic syndrome-refractory anemia cell line at lower concentrations. [ABSTRACT FROM AUTHOR]

• To avoid clustering among V atoms, PG unit cell should contain two V atoms. • Four H 2 are adsorbed around a V atom with the adsorption energy of −0.564 eV/H 2. • Ab initio MD simulation shows six H 2 can be adsorbed on both sides of V-PG at 300 K. • At 300 K and without external pressure, the hydrogen storage capacity is 4.58 wt%. Hydrogen storage capacity on vanadium (V) decorated porous graphene (PG) has been studied using first-principles calculations. The results show, to avoid a tendency of clustering among V atoms, the maximum number of adsorbed V atoms is two for both sides of the PG unit cell, and four H 2 molecules can be adsorbed around each V atom. Furthermore, at 300 K and without external pressure, ab initio molecular-dynamics simulations results show that six H 2 molecules can be stably adsorbed on both sides of unit cell of PG decorated with V atoms with the gravimetric hydrogen storage capacity of 4.58 wt%. [ABSTRACT FROM AUTHOR]

The geometric model of thermal barrier coatings (TBCs) was established. Two cases based on the standard thickness of the ceramic layer existed. These were the steps of TBCs thickness were being higher than the standard layer and those of lower than standard layer. The heat transfer processes of these two cases were simulated with the ANSYS software. The change process of thermal effusivity was analyzed in the two cases and the coating thickness differences effect on the surface temperature distributions of TBCs was analyzed through the time course curves of temperature difference. Moreover, the difficulty of detection for these two cases with infrared nondestructive testing was discussed according to maximum temperature difference and the maximum temperature contrast ratio. The result demonstrated that all curves of thermal effusivity with various thickness differences coincided with each other at the initial and longer times, where the ceramic layer thickness was lower than the standard layer. This was more easily detectable compared to the higher thickness and the maximum temperature contrast ratio or the maximum temperature difference increased as the coating thickness difference increased. [ABSTRACT FROM AUTHOR]

Hydrogen storage capacity on Titanium (Ti) decorated porous graphene (PG) has been investigated using density functional theory simulations with generalized gradient approximation method. The possible adsorption sites of Ti atom on PG and electronic properties of Ti-PG system are also discussed.The results show a Ti atom prefers to strongly adsorb on the center site above the C hexagon with the binding energy of 3.65 eV, and the polarization and the hybridization mechanisms both contribute to the Ti atom adsorption on PG. To avoid a tendency of clustering among Ti atoms, the single side of the PG unit cell should only contain one Ti atom. For the single side of PG, four H 2 molecules can be adsorbed around Ti atom, and the adsorption mechanism of H 2 molecules come from not only the polarization mechanism between Ti and H atoms but also the orbital hybridization among Ti atom, H 2 molecules and C atoms. For the case of double sides of PG, eight H 2 molecules can be adsorbed on Ti-decorated PG unit cell with the average adsorption energy of −0.457 eV, and the gravimetric hydrogen storage capacity is 6.11 wt.%. Furthermore, ab inito molecular-dynaics simulation result shows that six H 2 molecules can be adsorbed on double sides of unit cell of Ti-PG system and the configuration of Ti-PG is very stable at 300 K and without external pressure, which indicates Ti-decorated PG could be considered as a potential hydrogen storage medium at ambient conditions. [ABSTRACT FROM AUTHOR]

In this paper, we focus on analysis of the preamble-based joint estimation for channel and laser-frequency offset (LFO) in coherent optical filter bank multicarrier systems with offset quadrature amplitude modulation (CO-FBMC/OQAM). In order to reduce the noise impact on the estimation accuracy, we proposed an estimation method based on inter-frame averaging. This method averages the cross-correlation function of real-valued pilots within multiple FBMC frames. The laser-frequency offset is estimated according to the phase of this average. After correcting LFO, the final channel response is also acquired by averaging channel estimation results within multiple frames. The principle of the proposed method is analyzed theoretically, and the preamble structure is thoroughly designed and optimized to suppress the impact of inherent imaginary interference (IMI). The effectiveness of our method is demonstrated numerically using different fiber and LFO values. The obtained results show that the proposed method can improve transmission performance significantly. [ABSTRACT FROM AUTHOR]

Based on first-principles method, the electron structure of porous graphene (PG) and adsorption ability of H 2 molecular on Y-decorated porous graphene are investigated using CASTEP code. It is found that the bridge of C–C bond which connects two C hexagons is favorable site for a Y atom adsorbed on the single side of PG, and six H 2 molecules can be absorbed around a Y atom with average adsorption energy of −0.297 eV/H 2 computed by GGA-PBE functional. Though two Y atoms can be stably adsorbed on the same side of one unit cell of PG, there isn’t sufficient space for H 2 absorbing around each Y atom. To improve capability of hydrogen storage, the unit cell of PG with single side should only contain one Y atom. For the case of double side of porous graphene, two Y atoms are preferably located above the center of the different C hexagon. Fourteen H 2 molecules can be absorbed on both sides of PG, and the gravimetric hydrogen storage capacity is 7.87 wt.% with the average adsorption energy of −0.23 eV/H 2 . [ABSTRACT FROM AUTHOR]

To understand the variation and patterns of vegetation coverage in the Yellow River Basin, as well as to promote regional ecological protection and maintain ecological construction achievements, MOD13Q1 data at a resolution of 250 m were used to calculate the annual average normalised difference vegetation index (NDVI) in a time series from 2000 to 2010. Using a variation coefficient, a Theil–Sen Median trend analysis, the Mann–Kendall test, and the Hurst index method, this study investigated the temporal and spatial variations of vegetation coverage characteristics of the Yellow River Basin. The results showed that (1) the vegetation coverage of the Yellow River appeared to have an overall trend of high in the southeast and west and low in the northwest; (2) the averaged NDVI of the whole basin fluctuated in a range of 0.3 to 0.4 from 2000 to 2010 (from 2000 to 2004 there were larger variations and these have been growing rapidly since 2005); (3) the NDVI was stable, 73.4% of the vegetation-coverage area fluctuated with a low-to-medium amplitude, while 27.6% of the area varied by a large amplitude; (4) the regions with improved vegetation coverage (62.9%) were far greater than the degraded regions (27.7%), while the sustained invariant area accounted for 9.4% of the total vegetation coverage regions; and (5) 86% of the vegetation-covered area was positively sustainable. The areas with sustainable improvement accounted for 53.7% of the total vegetation coverage area; the invariant area accounted for 7.8%. The area with sustainable degradation was 24.5%; the future variation in trends of the residual (14%) could not be determined. Therefore, continuous attention must be given to the variation in trends of vegetation in the sustainably degraded and underdetermined regions. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the molecularly imprinted polymer layer of estriol at the silica nanoparticles surface with selective recognition had been constructed. The methacryl groups of functional monomer at the silica nanoparticles surface were acted as reactive sites to induce imprinting polymerisation. The absorption capacity results showed that the molecularly imprinted polymers had an excellent combining affinity, recognition selectivity and fast kinetics. Furthermore, the molecularly imprinted polymers were successfully used as absorbent of dispersive solid-phase extraction coupled with high-performance liquid chromatography to determinate trace estriol and estradiol in milk tablets. The high recoveries yielded of 89.1–93.5% were achieved with the relative standard deviations less than 9.4%. So, the molecularly imprinted polymers are the effective absorbents for the separation and enrichment of oestrogens in the complex matrices samples. [Copyright &y& Elsevier]

Abstract: In this paper, an electrochemical sensor for 17β-estradiol (E2) based on the molecular imprinting polymer (MIP) membranes had been constructed. 6-mercaptonicotinic acid (MNA) and E2 were first assembled on the surface of platinum nanoparticles-modified glassy carbon electrode (PtNPs/GCE) by the formation of Pt–S bonds and hydrogen-bonding interactions, and subsequently the polymer membranes were formed by electropolymerization. Finally, a novel molecularly imprinted sensor (MIS) was obtained after removal of E2. Experimental parameters such as deposition time, scan cycles, pH value and accumulation condition were optimized. Under optimal conditions, the MIS exhibited a large adsorption capacity and high selectivity. A good linearity was obtained in the range of 3.0×10−8–5.0×10−5 molL−1 (r =0.996) with an estimated detection limit of 1.6×10−8 molL−1. MIS had been successfully used to analyze E2 in water samples without complex pretreatment. Meanwhile, the average recoveries were higher than 93.9% with RSD<3.7%. All results above reveal that MIS is an effective electrochemical technique to determine E2 real-time in complicated matrix. [Copyright &y& Elsevier]

Abstract: In this paper, highly selective core–shell molecularly imprinted polymers of 17β-estradiol on the surface of silica nanoparticles (SiO2@E2-MIPs) were prepared. The SiO2@E2-MIPs were characterized by Fourier transform infrared spectrometer (FT-IR), transmission electron microscope (TEM), dynamic adsorption and static adsorption tests. The sorption capacity of the SiO2@E2-MIPs were nearly 5 times that of the non-imprinted polymers (NIPs), and it only took 25min to achieve the sorption equilibrium. It indicated that the SiO2@E2-MIPs exhibited a high selectivity, large adsorption capacity and fast kinetics. When the SiO2@E2-MIPs were used as dispersive solid-phase extraction (dSPE) absorbents to selectively enrich and determine estrogens in duck feed, the average recoveries of E2 and estriol (E3) were higher than 96.74% and 72.07%, respectively, and the relative standard deviations (RSD) of E2 and E3 were less than 1.61% and 3.28%, respectively. The study provides an effective method for the separation and enrichment of estrogens in the complex matrix samples by the SiO2@E2-MIPs. [ABSTRACT FROM AUTHOR]

This article describes the synthetic procedures for the preparation of crescent (and helical) aromatic oligoamides developed in recent years in our laboratory. The large-scale preparation of a variety of monomers derived from various tetrasubstituted benzenes is presented. Three different strategies for constructing various oligomers consisting of meta- and meta/para-linked benzene residues are discussed. Factors affecting coupling efficiency and yields are analyzed. The developed synthetic methods have provided the basis for the preparation of longer oligomers and for the development of solid-phase synthesis. [ABSTRACT FROM AUTHOR]

We report that the use of a hydrogen-bonded pyrimidine-macrocycle complex can efficiently facilitate the threading of two bispyridinium ethylenes into four rings, as evidenced by X-ray crystallography of its precursor, offering a rare example of a doubly threaded [6]rotaxane in 91% yield. The unusual architecture is found to be stable with no dethreading despite the large ring size of the macrocycle with respect to the stopper. [ABSTRACT FROM AUTHOR]

The Indian Ocean Region (IOR) has become one of the main economic forces globally, and countries within the IOR have attempted to promote their intra-regional trade. This study investigates the spatiotemporal evolution of the community structures of the intra-regional trade and the impact of determinant factors on the formation of trade community structures of the IOR from 1996 to 2017 using the methods of social network analysis. Trade communities are groups of countries with measurably denser intra-trade ties but with extra-trade ties that are measurably sparser among different communities. The results show that the extent of trade integration and the trade community structures of the IOR changed from strengthening between 1996 and 2014 to weakening between 2015 and 2017. The largest explanatory power of the formation of the IOR trade community structures was the IOR countries' economic size, indicating that market remained the strongest driver. The second-largest explanatory power was geographical proximity, suggesting that countries within the IOR engaged in intra-regional trade still tended to select geographically proximate trading partners. The third- and the fourth-largest were common civilization and regional organizational memberships, respectively. This indicates that sharing a common civilization and constructing intra-regional institutional arrangements (especially open trade policies) helped the countries within the IOR strengthen their trade communities. [ABSTRACT FROM AUTHOR]

The development of efficient and selective organic synthetic approaches for complex molecules has garnered significant attention due to the need for precise control over molecular structures and functions. Rotaxanes, a type of mechanically interlocked molecules (MIMs), have shown promising applications in various fields including sensing, catalysis, and material science. However, the highly selective synthesis of oligo[n]rotaxanes (mostly n≥3) through controlling host‐guest complexation and supramolecular threading assembly process still remains an ongoing challenge. In particular, the utilization of two‐dimensional (2D) macrocycles with structural shape‐persistency for the synthesis of oligo[n]rotaxanes is rare. In this concept, research on cooperatively threaded host‐guest complexation with hydrogen‐bonded (H‐bonded) aramide macrocycles and selective synthetic protocols of oligo[n]rotaxanes has been summarized. The high efficiency and selectivity in synthesis are ascribed to the synergistic interplay of multiple non‐covalent bonding interactions such as hydrogen bonding and intermolecular π–π stacking of macrocycles within the unique supramolecular structure of threaded host‐guest complexes. This review focuses on the latest progress in the concepts, synthesis, and properties of H‐bonded aramide macrocycle‐based oligorotaxanes, and presents an in‐depth outlook on challenges in this emerging field. [ABSTRACT FROM AUTHOR]

The selective recovery and utilization of Pd(II) from high-level liquid waste (HLLW) is highly desirable for both a flourishing circular economy and the sustainable development of nuclear energy. However, the design of suitable materials is an ongoing challenge due to the complicated composition and extremely radioactive and acidic conditions of HLLW, which requires exceptional selectivity and structural robustness of materials. In this study, two phenanthroline-based covalent organic polymers are constructed through polycondensation of 1,10-phenanthroline-2,9-dicarbaldehyde and 1,3,5-tris-(4-aminophenyl) triazine (COP-1) and subsequent oxidation of imine to amide groups (COP-2). COP-2 demonstrates a high adsorption capacity (318 mg g−1) and outstanding selectivity for Pd(II) over 17 competing cations at 3 M HNO3 and is stable at high acidity (2–6 M HNO3) and under a strong radiation field of up to 600 kGy γ irradiation. Additionally, COP-2 is reusable without an obvious decrease in adsorption efficiency after 5 cycles and is feasible for use in the dynamic column separation of Pd(II). More importantly, the Pd(II)-loaded COP-2 obtained from adsorption experiments can be employed as a highly efficient heterogeneous catalyst for Suzuki–Miyaura cross-coupling reactions with excellent reusability for more than 20 successive cycles. This work offers an example of turning wastes into wealth by rationally designing materials for precious metal recovery from HLLW and converting them into valuable catalysts. [ABSTRACT FROM AUTHOR]

A supramolecular approach using a polyviologen-pillar[5]arene complex as segregated ion pairs was shown to be highly efficient for the conversion of CO2 with epoxides into cyclic carbonates without the need for metals or solvents. The enhanced catalytic performance was achieved by cooperative ion pair segregation and CO2 fixation. [ABSTRACT FROM AUTHOR]

The capture of palladium from spent nuclear fuel is crucial for the sustainable development of nuclear energy and resource recovery. One of the most challenging issues in this direction is the survival of adsorbents under extreme reprocessing conditions such as strongly acidic media and high radiation fields while still maintaining high extraction ability and selectivity. Herein, an approach to addressing this issue is reported by incorporating macrocycle into nitrogen‐rich covalent organic polymers (COPs). Dramatically outperforming current adsorbing materials, pillar[5]arene‐based COPs with pyridyl and triazolyl functionalities display record adsorption capacity for Pd(II) at 3 M HNO3 (403 mg g−1), extraordinary stability under 500 kGy gamma irradiation, and ultra‐high selectivity toward Pd(II) over both 17 coexisting cations and six anions. In particular, the material P5COP‐m‐BPT with the best performance also shows remarkable dynamic adsorption efficiency for Pd(II). This study not only provides a strategy to enhance all‐sided adsorption performance in palladium separation with nitrogen‐rich COPs materials but also demonstrates the superiority of customizing advanced materials with macrocycles. [ABSTRACT FROM AUTHOR]

Research on stimuli-responsive host–guest systems is at the cutting edge of supramolecular chemistry, owing to their numerous potential applications such as catalysis, molecular machines, and drug delivery. Herein, we present a multi-responsive host–guest system comprising azo-macrocycle 1 and 4,4′-bipyridinium salt G1 for pH-, photo-, and cation- responsiveness. Previously, we reported a novel hydrogen-bonded azo-macrocycle 1. The size of this host can be controlled through light-induced E↔Z photo-isomerization of the constituent azo-benzenes. The host is found in this work to be capable of forming stable complexes with bipyridinium/pyridinium salts, and implementing guest capture and release with G1 under light in a controlled manner. The binding and release of the guest in the complexes can also be easily controlled reversibly by using acid and base. Moreover, the cation competition-induced dissociation of the complex 1a2⊃G1 is achieved. These findings are expected to be useful in regulating encapsulation for sophisticated supramolecular systems. [ABSTRACT FROM AUTHOR]

Use of abiotic chemical systems for understanding higher order superstructures is challenging. Here we report a ring‐in‐ring(s) system comprising a hydrogen‐bonded macrocycle and cyclobis(paraquat‐o‐phenylene) tetracation (o‐Box) or cyclobis(paraquat‐p‐phenylene) tetracation (CBPQT4+, p‐Box) that assembles to construct discrete higher order structures with adaptive conformation. As indicated by mass spectrometry, computational modeling, NMR spectroscopy, and single‐crystal X‐ray diffraction analysis, this ring‐in‐ring(s) system features the box‐directed aggregation of multiple macrocycles, leading to generation of several stable species such as H4G (1 a/o‐Box) and H5G (1 a/o‐Box). Remarkably, a dimeric shish‐kebab‐like ring‐in‐rings superstructure H7G2 (1 a/o‐Box) or H8G2 (1 a/p‐Box) is formed from the coaxial stacking of two ring‐in‐rings units. The formation of such unique dimeric superstructures is attributed to the large π‐surface of this 2D planar macrocycle and the conformational variation of both host and guest. [ABSTRACT FROM AUTHOR]

Use of abiotic chemical systems for understanding higher order superstructures is challenging. Here we report a ring‐in‐ring(s) system comprising a hydrogen‐bonded macrocycle and cyclobis(paraquat‐o‐phenylene) tetracation (o‐Box) or cyclobis(paraquat‐p‐phenylene) tetracation (CBPQT4+, p‐Box) that assembles to construct discrete higher order structures with adaptive conformation. As indicated by mass spectrometry, computational modeling, NMR spectroscopy, and single‐crystal X‐ray diffraction analysis, this ring‐in‐ring(s) system features the box‐directed aggregation of multiple macrocycles, leading to generation of several stable species such as H4G (1 a/o‐Box) and H5G (1 a/o‐Box). Remarkably, a dimeric shish‐kebab‐like ring‐in‐rings superstructure H7G2 (1 a/o‐Box) or H8G2 (1 a/p‐Box) is formed from the coaxial stacking of two ring‐in‐rings units. The formation of such unique dimeric superstructures is attributed to the large π‐surface of this 2D planar macrocycle and the conformational variation of both host and guest. [ABSTRACT FROM AUTHOR]

Despite vast applications of macrocycles in supramolecular chemistry, achieving long‐lived emissions including room‐temperature phosphorescence (RTP) or thermally activated delayed fluorescence (TADF) for potential use still presents a great challenge. This work first reports hydrogen‐bonded (H‐bonded) macrocycles emitting RTP and TADF by introducing various donors onto the same aramide skeleton containing a rigid acceptor. The formation of charge transfer effectively enhances the photoluminescence efficiency. Aromatic carbonyl groups promote the intersystem crossing. The drastically reduced flexibility of chromophores fixed by the H‐bonded macrocyclic framework contributes to suppress the nonradiative decay to stabilize triplet excitons. Therefore, RTP and TADF are acquired by altering donors, and are systematically revealed by comparisons with control compounds and theoretical calculations. Finally, near white‐light emission (CIE, 0.30, 0.33) is realized via host–guest interactions. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and investigate a design concept for a polyatomic photonic crystal ring resonator (PCRR). In contrast to conventional sensors, this PCRR comprises two different branching waveguides (WG), which are all oriented in the same lattice direction, but with different optical propagation properties due to the binary nature of the diatomic square lattice. Based on this new scheme, an on-chip biochemical sensor is proposed. Electromagnetic analysis, PWE and FDTD numerical techniques, were used to investigate the sensing performance. Our results show that such a sensor can efficiently detect small changes in the refractive index within the sensing area. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to compare the efficacy of mirabegron plus tamsulosin to tamsulosin monotherapy in terms of ureteral stent-related discomfort after ureteroscopic lithotripsy. Methods: A total of 102 patients undergoing ureteroscopic lithotripsy and silicone ureteral stent placement were enrolled in this study. Patients were randomized 1:1 to receive either tamsulosin 0.4 mg once daily or mirabegron 50 mg + tamsulosin 0.4 mg once daily during the stenting period. Before the operation, the IPSS, QOL, and pain score were collected. On the day of ureteral stent removal, the USSQ, analgesic usage amount was collected and recorded. Results: The median USSQ-body pain score in the tamsulosin group and tamsulosin + mirabegron group was 15 and 16, respectively (p = 0.530). The median analgesic usage in the two groups was 3 and 2, respectively (p = 0.170). The median USSQ-urinary symptoms, USSQ-general health, USSQ-work performance, USSQ-sexual matters, and USSQ-additional problems in the two groups were 26 and 26 (p = 0.194), 11 and 12 (p = 0.068), 12 and 13 (p = 0.105), 2 and 2 (p = 0.437), 9 and 9 (p = 0.533), respectively. The international patients used more analgesics than Chinese patients (6 vs. 1, p = 0.015). Conclusion: Compared to tamsulosin alone, tamsulosin + mirabegron showed no additional benefit on the ureteral stent-related pain control after ureteroscopic lithotripsy and silicone stent placement. There was no significant difference on the analgesic usage and USSQ scores between the two groups. Chinese patients request fewer analgesics than international patients. [ABSTRACT FROM AUTHOR]

Host–guest complexation using hydrogen-bonded macrocycles was found to enable activation of the Bobbitt oxidant reagent, which greatly facilitates the highly efficient oxidation of unactivated primary alcohols. This work provides a complementary approach to the activation of Bobbitt's salt with shape-persistent macrocycles in supramolecular catalysis. [ABSTRACT FROM AUTHOR]

Around 60% of in vitro fertilized (IVF) human embryos irreversibly arrest before compaction between the 3- to 8-cell stage, posing a significant clinical problem. The mechanisms behind this arrest are unclear. Here, we show that the arrested embryos enter a senescent-like state, marked by cell cycle arrest, the down-regulation of ribosomes and histones and down-regulation of MYC and p53 activity. The arrested embryos can be divided into 3 types. Type I embryos fail to complete the maternal-zygotic transition, and Type II/III embryos have low levels of glycolysis and either high (Type II) or low (Type III) levels of oxidative phosphorylation. Treatment with the SIRT agonist resveratrol or nicotinamide riboside (NR) can partially rescue the arrested phenotype, which is accompanied by changes in metabolic activity. Overall, our data suggests metabolic and epigenetic dysfunctions underlie the arrest of human embryos. Human embryos develop poorly in vitro, and as much as 60% of embryos will irreversibly arrest. This study shows that the arrested embryos enter a senescent-like state, and reveals that several mechanisms related to zygotic genome activation problems and erroneous metabolism can at least partly explain some of the reasons behind this arrest. [ABSTRACT FROM AUTHOR]

Exploration of host–guest complexation between a shape-persistent H-bonded macrocycle and flexible guests may enable construction of new pseudorotaxanes systems. Here, we present the impact of varying the spacer length of four bis(4-phenylpyridinium) guests G1-G4 on production of pseudorotaxanes with a 2D H-bonded macrocycle 1a. The host–guest complexes are probed by 1H NMR, 2D NOESY and UV–vis spectroscopic techniques. [2]- and [3]- pseudorotaxane assemblies are formed specifically using these guests, demonstrating the dependency of accessing [2]- and [3]- pseudorotaxane on the spacer length of these dications. Theoretical calculations reveal the difference in the conformation of the guests between these two binding modes: the one with a 1:1 stoichiometry (spacer length: C4 and C6) show Z-shaped conformation and the other with a 2:1 stoichiometry (spacer length: C8 and C10) take a linear conformation. The findings of the threading modes may help develop new H-bonded macrocycle-based rotaxanes and other related mechanically interlocked molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new strategy was proposed to make PVA/rGO composites by solvothermal reduction. [•] The solvent acted not only as a reducing agent but also as a good stabilizer. [•] The homogeneous dispersion of rGO sheets in the PVA matrix was achieved. [•] The crystallinity of PVA/rGO nanocomposites was investigated. [•] Mechanical properties and thermal stability were greatly improved by adding rGO. [Copyright &y& Elsevier]

Highlights: [•] Assembling the extracellular matrix (ECM) component of chondroitin sulfate (CS) into hydrogel network to mimic in vivo ECM. [•] Controllable release of fibroblast growth factor (FGF) in hydrogel network. [•] Hierarchical porous structure to resemble in vivo 3D microstructure. [Copyright &y& Elsevier]

A novel approach to efficient and selective construction of [4]rotaxane was proposed to demonstrate the superiority of H-bonded azo-macrocycles in forging higher order rotaxanes. The single crystal structure reveals the importance of the interplay of multiple non-covalent bonding interactions, particularly π-stacking interactions, in stabilizing the host–guest complex. This may open an avenue to the synthesis of oligomeric mechanically interlocked molecules containing fewer stations but more rings. [ABSTRACT FROM AUTHOR]

A four-step approach to perfluoro(2-(methoxymethoxy)ethyl vinyl ether) 5 from an acid-sensitive glycol ether 3 by liquid-phase direct fluorination (DF) has been described. The perfluoro precursor was achieved by control of the gradient increase of temperature (−20 °C to 15 °C) and addition of sodium fluoride. Improved workup with benzyl alcohol provided a convenient method for purification and a practical means for tracing the progress of fluorination. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the slow light properties of the polyatomic Photonic Crystal (PhC) which has multiple different air holes in each primitive cell are investigated. A slow light waveguide with “U-type” group index–frequency curve, which results in nearly constant group index over large bandwidth, is achieved using this new photonic crystal geometry based on the square lattice. Also, the radius and position of the innermost rows of small air holes have been modified to investigate the feasibility of controlling the dispersion relation by subtle structural modification. Numerical results demonstrate that decreasing the group velocity effectively and meanwhile maintaining a large Normalized Delay-Bandwidth Product (NDBP) can be achieved by only modifying the radius of the innermost rows of small air holes. Shifting the innermost rows of small air holes toward the waveguide core is highly beneficial to enlarge the slow light bandwidth, but it contributes nothing to the promotion of NDBP. Our results provide important theoretical basis for the potential application offered by the polyatomic photonic crystal in future optical networks. [Copyright &y& Elsevier]

Abstract: An analytical procedure for selective extraction of sildenafil and vardenafil in herbal dietary supplements (HDSs) has been set up by using the magnetic molecularly imprinted polymers (MMIPs) as the extraction and clean-up materials, followed by high performance liquid chromatography-ultraviolet (HPLC-UV). The MMIPs were prepared by a surface molecular imprinting technique, using Fe3O4 magnetite as a magnetically susceptible component, sildenafil as template molecule, 2-(trifluoromethyl) acrylic acid (TFMAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as polymeric matrix components. The MMIPs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM), respectively. The heterogeneity of the MMIPs was modeled with the Freundlich isotherm equation. The resulting MMIPs had high recognition ability and fast binding kinetics for sildenafil. The MMIPs were used as dispersive solid-phase extraction (DSPE) materials to selectively extract sildenafil and vardenafil from HDSs, the contents of sildenafil and vardenafil were found to be 8.05 and 3.86μgg−1, respectively, and the average recoveries in spiked HDSs were 70.91–91.75% with a relative standard deviation (R.S.D.) below 7%. The MMIPs were successfully used to selectively enrich and determine sildenafil and vardenafil from HDSs. [Copyright &y& Elsevier]

• Two nitrogen-rich covalent organic networks are constructed for Pd(II) capture. • CPN-1 sets a new record for Pd(II) uptake (535 mg g−1) from HNO 3 solution. • These CPNs are ultra-selective for Pd(II) over 17 coexisting competing cations. • CPNs exhibit exceptional robustness under high acidity and γ irradiation. • CPNs are fully reusable and feasible for dynamic column separation. Selective capture of palladium (Pd) from high-level liquid waste (HLLW) is one of the frontier issues in materials science in order to alleviate the Pd resource scarcity and guarantee the safe disposal of radioactive wastes. However, this task remains a great challenge in HLLW treatment associated with low capacity, poor selectivity, and limited stability of materials in strongly acidic and radioactive environments. Here we conquer this challenge by designing covalent polymeric networks (CPNs) equipped with abundant bidentate (CPN-1) or tridentate (CPN-2) nitrogen-rich moieties as specific nano-traps for Pd(II). These CPNs are constructed through efficient and facile click reactions, among which CPN-1 bearing plentiful pyridinyl-triazolyl moieties sets a new record for Pd(II) uptake capacity (535 mg g−1), notably surpassing all the reported materials for Pd(II) separation from HNO 3 solutions to date. Moreover, CPN-1 features additional attractive merits including good reusability, feasible dynamic column separation, outstanding Pd(II) selectivity over 17 coexisting cations, and excellent stability under highly acidic and radioactive conditions, making it highly promising for practical applications. This work provides a facile way to customize CPN adsorbents with superior performance and highlights the great potential of the prepared materials for metal capture applications. [ABSTRACT FROM AUTHOR]

Diminished ovarian reserve (DOR) is the weakening of ovarian oocyte production and quality. It will further become premature ovarian failure without timely cure. However, disease pathology and diagnostic markers are still incompletely understood. Liu-Wei-Di-Huang (LWDH) pill, a traditional Chinese medicine formula, is commonly used in the treatment of DOR in China. To explore the mechanism of the effect of LWDH on in vitro fertilization (IVF) outcomes in patients with DOR, a pseudotargeted metabolomics study combined with multivariate data processing strategy was carried out. A liquid chromatography tandem mass spectrometry-based metabolomics approach was applied to characterize metabolic biomarker candidates. Multiple pattern recognition was used to determine groups and confirm important variables. A total of 21 potential biomarkers were characterized, and related metabolic pathways were identified. The study displayed that the established pseudotargeted metabolomics strategy is a powerful approach for investigating the mechanism of DOR and LWDH. In addition, the approach may highlight biomarkers and metabolic pathways and can capture subtle metabolite changes from headache, which may lead to an improved mechanism understanding of DOR diseases and LWDH treatment. [ABSTRACT FROM AUTHOR]

Two hydrogen-bonded azo-macrocycles with little disparity of the side chains in steric hindrance exhibited a substantial difference in complexation (slow/fast exchange) towards bipyridinium. Inspired by this finding, these macrocycles were applied to efficiently and selectively construct [2]- and [3]rotaxanes through one-pot synthesis. The origin of the selectivity in this novel approach was elucidated by comparing single crystal structures, DFT calculations and stepwise synthesis. [ABSTRACT FROM AUTHOR]

A light‐responsive system constructed from hydrogen‐bonded azo‐macrocycles demonstrates precisely controlled propensity in molecular encapsulation and release process. A significant decrease in the size of the cavity is observed in the course of the E→Z photoisomerization based on the results from DFT calculations and traveling wave ion mobility mass spectrometry. These macrocyclic hosts exhibit a rare 2:1 host–guest stoichiometry and guest‐dependent slow or fast exchange on the NMR timescale. With the slow host–guest exchange and switchable shape change of the cavity, quantitative release and capture of bipyridinium guests is achieved with the maximum release of 68 %. This work underscores the importance of slow host–guest exchange on realizing accurate release of organic cations in a stepwise manner under light irradiation. The light‐responsive system established here could advance further design of novel photoresponsive molecular switches and mechanically interlocked molecules. [ABSTRACT FROM AUTHOR]

A light‐responsive system constructed from hydrogen‐bonded azo‐macrocycles demonstrates precisely controlled propensity in molecular encapsulation and release process. A significant decrease in the size of the cavity is observed in the course of the E→Z photoisomerization based on the results from DFT calculations and traveling wave ion mobility mass spectrometry. These macrocyclic hosts exhibit a rare 2:1 host–guest stoichiometry and guest‐dependent slow or fast exchange on the NMR timescale. With the slow host–guest exchange and switchable shape change of the cavity, quantitative release and capture of bipyridinium guests is achieved with the maximum release of 68 %. This work underscores the importance of slow host–guest exchange on realizing accurate release of organic cations in a stepwise manner under light irradiation. The light‐responsive system established here could advance further design of novel photoresponsive molecular switches and mechanically interlocked molecules. [ABSTRACT FROM AUTHOR]

Radiation stability of methoxypillar[5]arene (1) and n-butoxypillar[5]arene (2) was studied by an electron accelerator with dose up to 14 MGy in air at room temperature. The radiolysis products and the possible radiolytic mechanism were also proposed. The structures of both irradiated and unirradiated pillar[5]arenes samples were comparatively characterized by Micro-FTIR NMR, UV-vis, MALDI-TOF-MS and HPLC measurement. The results showed that the skeleton of the pillar[5]arenes was stable to a great extent when the dose was lower than 100 kGy, indicating excellent radiation stability of alkylated pillar[5]arenes. When the dose was more than 300 kGy, all compounds showed different degrees of radiation damage, leading to the radiolysis products via breakage of appending arms and the bond between α-carbon and β-carbon of appending arms of pillar[5]arenes. With increasing the dose, the degree of radiation damage from electron beam irradiation to pillar[5]arenes skeleton experienced a gradual rise. As the dose reached 2000 kGy, the compounds 1 and 2 decomposed by 21% and 33%, respectively, as a result of radiolytic degradation. Furthermore, the side chain length of alkyl groups will also significantly affect the irradiation stability of pillar[5]arenes, particularly at the dose beyond 2000 kGy. These results provide reliable data support for the radiation stability of alkylated pillar[5]arenes in a wide range of irradiation dose. • Radiation stability of methoxypillar[5]arene and butoxypillar[5]arene is explored. • The skeleton of the two pillar[5]arenes is stable at the dose lower than 100 kGy. • Longer chains promote marke radiolytic degradation compared to shorter ones. • Possible radiolytic pathway involving phenolic, quinone and methoxy group species is proposed. [ABSTRACT FROM AUTHOR]

• Obviously improved the reference genome for water spinach. • Greatly increase the BUSCO complete rate of the protein-coding genes. • Corrected a WGT event that occurred in water spinach, not the previously reported WGD. • Corrected 6 pseudo-chromosomes that with some incorrectly clustered, ordered, or orientated contigs in previous study. Water spinach (Ipomoea aquatica Forssk.) is an important green leafy vegetable in Asia, with high content of dietary fiber, minerals, and vitamins. The genome sequence of water spinach cv. HNUWS001 was published in 2021 with PacBio and Illumina sequences. However, this assembly showed low contig continuity and low BUSCO complete rate for the genes. Here, we reported a high-quality chromosome-level reference genome for water spinach by integrating PacBio high-fidelity (HiFi) sequencing and Hi-C technology. The water spinach assembly was improved 492.2 Mb in size, with chromosome anchoring rate of 96.5%, contig N50 size of 23.5 Mb, and BUSCO complete rate of 99%. Telomeric repeat analysis indicates that 13 of the 15 pseudo-chromosomes have both-end telomeric repeats, including 4 gapless and telomere to telomere pseudo-chromosomes. We identified 36,014 protein-coding genes in the improved water spinach assembly, with BUSCO complete rate of 99.0%, and 88.5% of genes were functionally annotated. In addition, we identified 8,853 rRNA genes in our assembly, with 5S, 5.8S, 18S, and 28S rRNA genes were 5,235, 1,199, 1,227, and 1,192, respectively. Besides, evolution analysis based on the improved gene set suggested a whole genome triplication (WGT) event that occurred in water spinach, not the previously reported whole genome duplication (WGD) event. The improved genome assembly has a 14-fold increase in contig N50 size, a 15.5% increase in chromosome anchoring rate, and a 3.1% increase in BUSCO complete rate of the gene set, and corrected 6 pseudo-chromosomes that with some incorrectly clustered, ordered, or orientated contigs in previous study. The results of water spinach assembly and annotation provides a valuable resource for genetic studies and will facilitate future research aimed at improving agronomic traits. [ABSTRACT FROM AUTHOR]

Design of superior adsorbents for selective palladium recovery from secondary resources is of great significance but still remains a challenge. Herein, a series of covalent organic polymers (COPs) with abundant cationic open architectures were designed for selective palladium adsorption. Two classes of adsorbent materials COP-1 and COP-2 were created by polymerization of 1-methyl-3-phenyl-1H-imidazolium iodide with biphenyl and with p -terphenyl , respectively. After treating with NaX (X = Cl, Br, I) for anion exchange, the resulting polymers COP-1 were selected for investigating the effect of counter anions on palladium sorption. Among these materials, COP-1-Cl shows the highest uptake capacity (246.7 mg/g) for palladium at pH 3.0. In addition, COP-1-Cl and COP-2-Cl exhibited fast sorption kinetics (3 min) and excellent selectivity for palladium over 7 coexisting competing ions. The COP-1-Cl polymer also displayed good one-round enrichment capacity of 201 mg/g for palladium in the dynamic breakthrough experiment, demonstrating its potential in practical applications. The results from XPS experiments and SEM-mapping indicated that the sorption mechanism is involved in the anion exchange between Cl− in the materials and PdCl 4 2− species in solution, which has been proved to be spontaneous according to DFT calculations. The sorption capacities of COP-1 with different counter anions showed the order of Cl− > I− > Br−. This is consistent with the adsorption energies for the anion exchange processes calculated with different anions of the materials. The present work has provided a series of promising materials for palladium recovery and insights into the effect of counter anions on the sorption performance by integrated experimental studies and DFT simulations. [Display omitted] • Four novel cationic covalent organic polymers (COPs) were prepared for the first time. • These COPs were first employed to effectively recover palladium. • Superior adsorption capacity (246.7 mg/g) and fast kinetics (3 min) were achieved. • These COPs show excellent selectivity for palladium in the presence of 7 competing ions. [ABSTRACT FROM AUTHOR]

The hydrogen storage properties of the Scandium (Sc) atom modified Boron (B) doped porous graphene (PG) system were studied based on the density functional theory (DFT). For a single Sc atom, the most stable adsorption position on B-PG is the boron-carbon hexagon center after doping with the B atom. The corresponding adsorption energy of Sc atoms was −4.004 eV. Meanwhile, five H2 molecules could be adsorbed around a Sc atom with the average adsorption energy of −0.515 eV/H2. Analyzing the density of states (DOS) and the charge population of the system, the adsorption of H2 molecules in Sc-B/PG system is mainly attributed to an orbital interaction between H and Sc atoms. For the H2 adsorption, the Coulomb attraction between H2 molecules (negatively charged) and Sc atoms (positively charged) also played a critical role. The largest hydrogen storage capacity structure was two Sc atoms located at two sides of the boron-carbon hexagon center in the Sc-B/PG system. Notably, the theoretical hydrogen storage capacity was 9.13 wt.% with an average adsorption energy of −0.225 eV/H2. B doped PG prevents the Sc atom aggregating and improves the hydrogen storage effectively because it can increase the adsorption energy of the Sc atom and H2 molecule. [ABSTRACT FROM AUTHOR]

Pillararenes are macrocyclic oligomers of alkoxybenzene akin to calixarenes but tethered at the 2,5-positions via methylene bridges. Benefiting from their unique pillar-shaped architecture favorable for diverse functionalization and versatile host–guest properties, pillararenes decorated with chelating groups worked excellently as supporting platforms to construct extractants or adsorbents for metal ion separation. This feature article provides a detailed summary of pillararenes in Ln/An separation by liquid–liquid extraction and heavy metal separation by solid–liquid extraction. The preorganization effect of the rigid pillararene framework has a profound impact on the extraction of metal ions, and a unique extraction mechanism is observed when employing ionic liquids as solvents. The rich host–guest chemistry of pillararenes enables construction of a wide variety of supramolecular materials as metal ion adsorbents. We also discuss the differences between pillararenes and several well-known macrocycles, with a focus on the metal–ligand coordination and its influencing factors. We hope this review will provide useful information and unleash new opportunities in this field. [ABSTRACT FROM AUTHOR]

Three new hydrogen-bonded aromatic amide macrocycles with eight residues were synthesized. The first single crystal structure of this class of larger macrocycles was obtained, which reveals a saddle-like conformation. Interestingly, in sharp contrast to previous negative cooperativity in binding paraquat with cyclo[6]aramide, strong positive allosteric cooperativity in ternary complexes was observed. This may open an avenue for the construction of mechanically interlocked molecules with these larger H-bonded macrocycles. [ABSTRACT FROM AUTHOR]

Based on the first-principles method of density functional theory and the transition state theory, the adsorption, occupancy and diffusion behaviors of H atoms in LaFeO3(010) surface with O vacancy are investigated. It is found that, for the LaFeO3(010) surface with O vacancy, the H atom prefers to adsorb on the O atom and also could adsorb on the Fe atom; the adsorption energy of H atom in the surface layer is the biggest, while the adsorption energy decreases with the H atom in-depth diffusion to the bulk; the diffusion of H atoms from the surface layer to the bulk phase is a process of progressive rotation around the O atom, and the stepwise diffusion is more likely to occur than the direct diffusion. If the H atom can cross the barrier and diffuse from the surface to the subsurface, it will be more likely to diffuse inward. The presence of O vacancy can reduce the barrier for H atoms diffusion from the surface to the subsurface, and then improve the diffusion properties of the LaFeO3(010) surface system. [ABSTRACT FROM AUTHOR]