Ultrathin Free-Standing Porous Aromatic Framework Membranes for Efficient Anion Transport.

Porous aromatic frameworks (PAFs) show promising potential in anionic conduction due to their high stability and customizable functionality. However, the insolubility of most PAFs presents a significant challenge in their processing into membranes and subsequent applications. In this study, continuous PAF membranes with adjustable thickness were successfully created using liquid-solid interfacial polymerization. The rigid backbone and the stable C-C coupling endow PAF membrane with superior chemical and dimensional stabilities over most conventional polymer membranes. Different quaternary ammonium functionalities were anchored to the backbone through flexible alkyl chains with tunable length. The optimal PAF membrane exhibited an OH- conductivity of 356.6 mS ⋅ cm-1 at 80 °C and 98 % relative humidity. Additionally, the PAF membrane exhibited outstanding alkaline stability, retaining 95 % of its OH- conductivity after 1000 hours in 1 M NaOH. To the best of our knowledge, this is the first application of PAF materials in anion exchange membranes, achieving the highest OH- conductivity and exceptional chemical/dimensional stability. This work provides the possibility for the potential of PAF materials in anionic conductive membranes.

Porous organic framework membranes based on interface-induced polymerisation: design, synthesis and applications.

Porous organic frameworks (POFs) are novel porous materials that have attracted much attention due to their extraordinary properties, such as high specific surface area, tunable pore size, high stability and ease of functionalisation. However, conventional synthesised POFs are mostly large-sized particles or insoluble powders, which are difficult to recycle and have low mass transfer efficiencies, limiting the development of their cutting-edge applications. Therefore, processing POF materials into membrane structures is of great significance. In recent years, interface engineering strategies have proved to be efficient methods for the formation of POF membranes. In this perspective, recent advances in the use of interfaces to prepare POF membranes are reviewed. The challenges of this strategy and the potential applications of the formed POF membranes are discussed.

Continuous Ultrathin Zwitterionic Covalent Organic Framework Membrane Via Surface-Initiated Polymerization Toward Superior Water Retention.

Efficient construction of proton transport channels in proton exchange membranes maintaining conductivity under varied humidity is critical for the development of fuel cells. Covalent organic frameworks (COFs) hold great potential in providing precise and fast ion transport channels. However, the preparation of continuous free-standing COF membranes retaining their inherent structural advantages to realize excellent proton conduction performance is a major challenge. Herein, a zwitterionic COF material bearing positive ammonium ions and negative sulphonic acid ions is developed. Free-standing COF membrane with adjustable thickness is constructed via surface-initiated polymerization of COF monomers. The porosity, continuity, and stability of the membranes are demonstrated via the transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) characterization. The rigidity of the COF structure avoids swelling in aqueous solution, which improves the chemical stability of the proton exchange membranes and improves the performance stability. In the higher humidity range (50-90%), the prepared zwitterionic COF membrane exhibits superior capability in retaining the conductivity compared to COF membrane merely bearing sulphonic acid group. The established strategy shows the potential for the application of zwitterionic COF in the proton exchange membrane fuel cells.

Electrospun VO2/carbon fibers for aqueous zinc-ion batteries.

Aqueous zinc-ion batteries (AZIBs) have become one of the most potential energy storage devices due to their high safety and low cost. Vanadium oxide is an ideal cathode material for AZIBs because of its unique tunnel structure and multivalent nature. In this work, electrospun VO2/carbon fibers (VO2@CPAN) with a three-dimensional (3D) network are obtained by an electrospinning strategy combining with a controlled heat treatment. As cathode for AZIBs, the 3D network of the carbon fiber significantly improves the conductivity of VO2, avoids the agglomeration of VO2, and increases the stability of VO2. Therefore, VO2@CPAN delivers a specific capacity of 323.2 mA h g-1 at 0.2 A g-1, which is higher than pure VO2. At the same time, excellent capacity retention of 76.6% is obtained at high current density of 10 A g-1 after 3000 cycles.

Clear cell sarcoma in the post-molar area: Report of an ultra-rare case and literature review of oral clear cell sarcoma.

BACKGROUND: Clear cell sarcoma of soft tissue is an exceptionally rare sarcoma. It is even rarer in the oral cavity. To our knowledge, this case is the first reported clear cell sarcoma involving the post-molar area. Pathologically, clear cell sarcoma has low mitotic activity, rare nuclear pleomorphism, and necrosis. Its biological behavior is often underestimated by morphology. It is a highly aggressive tumor. CASE REPORT: A 39-year-old female presented with an asymptomatic mass in the post-molar area. It was mistaken for a benign or low-grade malignant tumor based on frozen incisional biopsy samples. The surgical resection sample was tested by NGS, which detected a rare EWSR1::CREB1 in clear cell sarcoma. The final diagnosis was made by combining morphological, immunohistochemical, and molecular test results. The patient did not receive any adjuvant therapy after surgery and no recurrence of the disease was detected at 8 months of follow-up. CONCLUSION: The study highlights that mild histological manifestation in the oral cavity should be considered the possibility of CCS affecting young patients. Careful histological investigation, sufficient immunohistochemical staining, and molecular tests are essential to the diagnosis.

Tailored preparation of porous aromatic frameworks in a confined environment.

The growth of porous aromatic frameworks (PAFs) on the surface of polymer brushes is reported for the first time. In contrast to PAFs formed in solution, polymer brushes provide a confined environment for PAF growth, resulting in nanosized and homogeneous spherical PAFs formed amongst the polymer brushes. 4-Bromobenzene functionalities from the polymer brushes are utilized to induce PAF growth by a Yamamoto-type Ullman coupling reaction. The size of PAFs can be tailored from 30 nm to 500 nm by subtly changing the structural parameters: e.g. reaction time, grafting density, and concentration of 4-bromobenzene on the surface. The established strategy is not only applicable to the preparation of PAF-1, but can also be extended to the controlled preparation of PAF-5. In addition, free-standing and flexible PS/PAF-1 hybrid membranes are obtained via dissolving the oxidized layer between the polymer layer and the silicon substrate, which can be transferred to any flat substrate. The obtained PS/PAF-1 membrane is proven to show high efficiency in removing dye from water and is promising for eliminating other foulants, such as microorganisms and trace organics.

Crystallinity Regulation and Defects Passivation for Efficient and Stable Perovskite Solar Cells Using Fully Conjugated Porous Aromatic Frameworks.

Fully conjugated porous aromatic frameworks (PAFs) have been constructed through Gilch reaction. The obtained PAFs have rigid conjugated backbones, high specific surface area, and excellent stability. The prepared PAF-154 and PAF-155 have been successfully applied in the perovskite solar cells (PSCs) by doping into the perovskite layer. The champion PSC devices afford a power conversion efficiency of 22.8 % and 22.4 %. It is found that the PAFs can be used as an efficient nucleation template, thus regulating the perovskite crystallinity. Meanwhile, PAFs can also passivate defects and promote carriers transporting in the perovskite film. By the comparative study with their linear counterpart, we unravel that the efficacy of PAFs is highly related to their porous structure and rigid fully conjugated networks. The unencapsulated devices with PAFs doping exhibit outstanding long-term stability, retaining 80 % of their initial efficiencies after half-year storage in ambient conditions.

Rare renal cell carcinoma with haemangioblastoma-like features and leiomyomatous stroma: report of a unique case with TSC2 and SETD2 variations.

BACKGROUND: Renal cell carcinoma (RCC) with haemangioblastoma-like characteristics is a type of RCC reported in recent years. RCC with (angio) leiomyomatous stroma (RCCLMS) was included as a provisional entity of the 2016 World Health Organization (WHO) classification. RCC with haemangioblastoma-like characteristics and leiomyomatous stroma is extremely rare. This is the first report of a rare tumour harbouring TSC2 and SETD2 variations. CASE PRESENTATION: The patient was a 38-year-old woman who presented with discomfort in the area of her right kidney. Ultrasound and enhanced CT showed a right renal mass, and clear cell renal cell carcinoma (CCRCC) was suspected; hence, robot-assisted laparoscopic nephron-sparing partial nephrectomy was performed. Gross examination revealed a well-circumscribed tumour measuring 2.0 cm × 1 cm × 0.7 cm under the renal capsule adjacent to the stripping edge that was greyish yellow and greyish red in colour. Histologic examination showed that the tumour consisted of three different structures: a CCRCC-like region, a haemangioblastoma-like region, and a focal leiomyomatous stroma component. Based on immunohistochemistry, the CCRCC-like region was diffusely strongly positive for AE1/AE3, vimentin, CAIX, PAX8, PAX2, CK7, and CAM5.2, partly positive for HNF1α, and negative for CD10, α-inhibin, NSE, S-100, CD34, and TFE3. The haemangioblastoma-like area was diffusely positive for vimentin, CAIX; partly positive for PAX8, PAX2, α-inhibin, and S-100; mostly positive for NSE; and slightly positive for HNF1α; the CD34 staining highlighted the complex capillary network. The Ki67 index was approximately 1-2% in the two above areas, and the leiomyomatous stroma was strongly positive for SMA. The whole-exon sequencing (WES) showed TSC2 and SETD2 variations. There was no progression after 18 months of follow-up. CONCLUSION: We report for the first time a unique case of RCC with haemangioblastoma-like features and leiomyomatous stroma accompanied by rare molecular abnormalities. Whether this is a new tumour entity or a variant of clear cell carcinoma remains to be determined. The biological behaviour and clinical characteristics need to be further examined.

Two-Dimensional Covalent Heptazine-Based Framework Enables Highly Photocatalytic Performance for Overall Water Splitting.

Screening high-efficiency 2D conjugated polymers toward visible-light-driven overall water splitting (OWS) is one of the most promising but challenging research directions to realize solar-to-hydrogen (STH) energy conversion and storage. "Mystery molecule" heptazine is an intriguing hydrogen evolution reaction (HER) building block. By covalently linking with the electron-rich alkynyl and phenyl oxygen evolution reaction (OER) active units, 10 experimentally feasible 2D covalent heptazine-based frameworks (CHFs) are constructed and screened four promising visible-light-driven OWS photocatalysts, which are linked by p-phenyl (CHF-4), p-phenylenediynyl (CHF-7), m-phenylenediynyl (CHF-8), and phenyltriynyl (CHF-9), respectively. Their HER and OER active sites achieve completely spatially separated, where HER active sites focus on heptazine units and OER active sites located on alkynyl or phenyl units. Their lower overpotentials allow them to spontaneously trigger the surface OWS reaction under their own light-induced bias without using any sacrificial agents and cocatalysts. Among them, CHF-7 shows the best photocatalytic performance with an ideal STH energy conversion efficiency estimated at 12.04%, indicating that it is a promising photocatalyst for industrial OWS. This work not only provides an innovative idea for the exploration of novel polymer photocatalysts for OWS but also supplies a direction for the development of heptazine derivatives.

Water-Dispersible Porous Aromatic Frameworks with Quasi-Amino Acid Structures via N-H Insertion Reactions.

As a class of materials with large specific surface area and chemical stability, porous aromatic frameworks (PAFs) have attracted much attention in the fields of gas adsorption, separation, and catalysis. However, synthetic methods for PAFs have been limited to a few coupling reactions, and PAF powders were usually obtained with a diameter of micrometer size. Here, we demonstrate an efficient N-H insertion reaction of diazoesters in the synthesis of PAFs with a diameter <200 nm. The established polymerization can be performed at room temperature, and four PAFs with different skeletons and composition can be obtained in high yields. The prepared PAFs have appreciable thermal and chemical stabilities. Because of the presence of ester groups in the backbone, the prepared PAFs with α-phenylglycine fragments can be easily obtained through the successive hydrolysis of the ester groups. The synthesized PAFs bearing phenylglycine moieties exhibit good water dispersibility and low cytotoxicity. We further show the potential of these PAFs in drug loading and photodynamic therapy.

Chlorogenic Acid-Loaded Mesoporous Silica Nanoparticles Modified with Hexa-Histidine Peptides Reduce Skin Allergies by Capturing Nickel.

Nickel-induced contact dermatitis is a severe allergic reaction to objects or environments that contain nickel. Many nanomaterials have been developed to reduce skin allergies by capturing nickel, but few agents are effective and safe. In this work, mesoporous silica nanoparticles (MSN) were synthesized and decorated with hexa-histidine peptides (denoted as MSN-His6), making it a strong nickel chelator. Subsequently, a dietary polyphenol, chlorogenic acid, was loaded into the mesopores of MSN (denoted as MSN-His6@CGA), realizing the potential of its anti-inflammatory properties. In vitro and in vivo experiments revealed that the synthesized MSN-His6@CGA nanoparticles exhibited more stable and stronger chelation, better biocompatibility, and ideal allergy-relieving ability, whether for environmental metal contamination or for allergic contact dermatitis caused by prolonged nickel exposure. Thus, the application of mesoporous silica-based nanoparticles may represent an ideal approach to alleviate skin allergies by capturing nickel, which would benefit people who suffer from metal-induced contact dermatitis.

Brush-like polymers: design, synthesis and applications.

With the development of controlled polymerisation, almost all polymerisation strategies have been successfully transplanted to surface-initiated polymerisation. The resulting polymer brushes have emerged as an effective tool for surface functionalization and modulation of the surface properties of materials. To meet various demands it is possible to tailor a material surface with polymer brushes that have diverse dimensionalities, morphologies and compositions. The crowded environment within polymer brushes as well as the stretched conformation of polymer chains sometimes provide unique physicochemical properties, which lead to the delicate creation of inorganic-organic hybridised nanostructures, anti-fouling coatings, biomedical carriers, and materials for use in lubrication, photonics and energy storage. So far, challenges remain in the high-precision synthesis and topological control needed to realize extended applications of polymer brushes. In this Feature Article, we highlight the topology, potential application prospects and various synthetic protocols, particularly for recently established methods, for the efficient synthesis of polymer brushes, as well as their benefits and limitations.

A Universal and Reversible Wet Adhesive via Straightforward Aqueous Self-Assembly of Polyethylenimine and Polyoxometalate.

The excellent adhesion of mussels under wet conditions has inspired the development of numerous catechol-based wet adhesives. Nevertheless, the performance of catechol-based wet adhesive suffers from the sensitivity toward temperature, pH, or oxidation stimuli. Therefore, it is of great significance to develop non-catechol-based wet adhesives to fully recapitulate nature's dynamic function. Herein, a novel type of non-catechol-based wet adhesive is reported, which is readily formed by self-assembly of commercially available branched polyethylenimine and phosphotungstic acid in aqueous solution through the combination of electrostatic interaction and hydrogen bonding. This wet adhesive shows reversible, tunable, and strong adhesion on diverse substrates and further exhibits high efficacy in promoting biological wound healing. During the healing of the wound, the as-prepared wet adhesive also possesses inherent antimicrobial properties, thus avoiding inflammations and infections due to microorganism accumulation.

Surface-Mediated Construction of an Ultrathin Free-Standing Covalent Organic Framework Membrane for Efficient Proton Conduction.

As a new class of crystalline porous organic materials, covalent organic frameworks (COFs) have attracted considerable attention for proton conduction owing to their regular channels and tailored functionality. However, most COFs are insoluble and unprocessable, which makes membrane preparation for practical use a challenge. In this study, we used surface-initiated condensation polymerization of a trialdehyde and a phenylenediamine for the synthesis of sulfonic COF (SCOF) coatings. The COF layer thickness could be finely tuned from 10 to 100 nm by controlling the polymerization time. Moreover, free-standing COF membranes were obtained by sacrificing the bridging layer without any decomposition of the COF structure. Benefiting from the abundant sulfonic acid groups in the COF channels, the proton conductivity of the SCOF membrane reached 0.54 S cm-1 at 80 °C in pure water. To our knowledge, this is one of the highest values for a pristine COF membrane in the absence of additional additives.

Construction of the 1D Covalent Organic Framework/2D g-C3N4 Heterojunction with High Apparent Quantum Efficiency at 500 nm.

The reasonable construction of heterojunction photocatalysts with clear nanostructures and a good interface contact especially the one-dimensional/two-dimensional (1D/2D) composite heterojunction with unique morphology is considered one of the most effective strategies for designing highly efficient photocatalysts. Herein, a series of the 1D ß-keto-enamine-based covalent organic framework (COF)/2D g-C3N4 composite materials COF-CN (1:x; where 1:x represents the mass ratio of COF and g-C3N4, x = 2.5, 5, 10, 15, 20) is prepared through the in situ reaction of 2,4,6-triformylphloroglucinol (Tp) and benzidine (BD) in stripped g-C3N4 suspension. A series of characterizations, such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), have verified their 1D/2D heterojunction structure. With the introduction of 1D COF nanobelts, the absorption of the composite is largely extended to 560 nm. Photocatalytic experiments reveal that the composite COF/CN shows evidently superior photocatalytic performance than individual COF and g-C3N4. The optimized COF-CN (1:10) exhibits a H2 production rate of 12.8 mmol g-1·h-1 under visible-light (λ ≥ 420 nm) irradiation, which is about 62 and 284 times higher than those of COF and g-C3N4, respectively. The apparent quantum efficiency (AQE) of COF-CN (1:10) is about 15.09% under 500 nm light irradiation, which is one of the highest among previous COF- or g-C3N4-based materials. This work provides important strategies for designing and constructing high-efficiency heterojunction photocatalysts with multidimensional features.

Pt-O bond as an active site superior to Pt0 in hydrogen evolution reaction.

The oxidized platinum (Pt) can exhibit better electrocatalytic activity than metallic Pt0 in the hydrogen evolution reaction (HER), which has aroused great interest in exploring the role of oxygen in Pt-based catalysts. Herein, we select two structurally well-defined polyoxometalates Na5[H3Pt(IV)W6O24] (PtW6O24) and Na3K5[Pt(II)2(W5O18)2] (Pt2(W5O18)2) as the platinum oxide model to investigate the HER performance. Electrocatalytic experiments show the mass activities of PtW6O24/C and Pt2(W5O18)2/C are 20.175 A mg-1 and 10.976 A mg-1 at 77 mV, respectively, which are better than that of commercial 20% Pt/C (0.398 A mg-1). The in situ synchrotron radiation experiments and DFT calculations suggest that the elongated Pt-O bond acts as the active site during the HER process, which can accelerate the coupling of proton and electron and the rapid release of H2. This work complements the knowledge boundary of Pt-based electrocatalytic HER, and suggests another way to update the state-of-the-art electrocatalyst.

Electrocatalytic performance of ultrasmall Mo2C affected by different transition metal dopants in hydrogen evolution reaction.

Molybdenum carbides are considered as one type of privileged noble-metal-free electrocatalysts for hydrogen evolution reactions (HER) due to their d-band electron structure, which is similar to Pt. Especially, the electronic structure of such materials can be further adjusted by elemental doping to improve their electrocatalytic activity. Herein, we selected the Anderson-type polyoxometalates (POMs) (NH4)n[TMMo6O24H6]·5H2O (TM = Ni2+, Co2+, n = 4; TM = Fe3+, Cr3+, n = 3) as precursors to prepare new transition-metal-doped Mo2C materials. When these POMs were mixed with dicyandiamide (DCA) by solid grinding, and carbonized at a high temperature, a series of Ni-, Co-, Fe-, and Cr-doped Mo2C composite nanoparticles covered by few-layer graphitic carbon shells (abbr. TM-Mo2C@C) were obtained. All these nanoparticles possess a similar size, morphology, and TM/Mo component ratio, and thus it is feasible to systematically investigate the influence of different TM dopants on the electrocatalytic activity of Mo2C for HER. Both electrocatalytic experiments and DFT calculations reveal that TM dopants have a significant effect on the hydrogen binding energy (ΔGH*) and the catalytic activity of Mo2C. The sequence of HER electrocatalytic activity is as follows: Ni-Mo2C > Co-Mo2C > Fe-Mo2C > Cr-Mo2C. As a result, Ni-Mo2C@C possesses the best HER performance, which required an overpotential of 72 mV at a current density of 10 mA cm-2 and the Tafel slope is 65.8 mV dec-1. This work suggests a shortcut to reasonably investigate the effects of elemental doping on molybdenum carbides and explore new high-efficient and low-cost electrocatalysts for HER.

Micropapillary component in gastric adenocarcinoma: an aggressive variant associated with poor prognosis.

BACKGROUND: Adenocarcinomas with a micropapillary component (MPC) have been described as an unusual morphological variant in various organs. However, few reports have described MPCs in gastric carcinomas, and the clinicopathological features of MPC are unclear. METHODS: Immunohistochemistry was used to detect the expression of epithelial membrane antigen, CK7, CK20, p53, epidermal growth factor receptor, ß-catenin, c-erbB-2, and Ki-67. Correlation of the MPC to tumor stage, lymph node metastasis, and lymphovascular invasion was performed using Fisher's exact test. Kaplan-Meier estimates were used to analyze overall survival. RESULTS: Immunohistochemical staining demonstrated that micropapillary and conventional gastric carcinomas showed similar positivity rates for all markers. However, aberrant expression of E-cadherin was detected in the tumors with MPCs without immunoreactivity in the stroma face. Epithelial membrane antigen showed the characteristic inside-out staining pattern of MPCs. Lymphatic invasion (P = 0.003), venous invasion (P = 0.017), lymph node metastasis (P = 0.014), and tumor stage (P = 0.022) were significantly increased in patients with MPCs when compared with conventional adenocarcinomas. MPC subtype II had a significantly higher frequency of lymph node metastasis than subtype I (P = 0.014). However, the proportion of MPC was not associated with lymph node metastases (P = 0.136). Overall survival of patients with an MPC was significantly shorter than that of patients with conventional adenocarcinomas (P = 0.031). In addition, overall survival was significantly lower in patients with a subtype II MPC growth pattern than in those with subtype I MPC in gastric carcinomas (P = 0.040). CONCLUSION: Gastric adenocarcinomas with MPC appear to be an aggressive variant associated with a poor prognosis. MPCs occurring in gastric adenocarcinomas should be included in surgical pathology reports, even if the proportion of MPC in the lesions is very low in the lesion.

Pulmonary adenocarcinoma with osseous metaplasia: a rare occurrence possibly associated with early stage?

Adenocarcinoma is the most common type of malignant pulmonary tumor, but osseous metaplasia of this tumor is extremely rare. To date, only 21 cases have been reported in the literature worldwide. Here, we report a case of primary pulmonary adenocarcinoma with benign osseous stromal metaplasia in a 60-year-old woman and discuss the pathogenesis of intratumoral ossification and review the relevant literature. We found that pulmonary adenocarcinoma with osseous metaplasia may be more likely to occur in early tumor stages.

CCL19/CCR7 upregulates heparanase via specificity protein-1 (Sp1) to promote invasion of cell in lung cancer.

CCL19/chemokine receptor 7 (CCR7) has been found to be associated with tumor growth, angiogenesis, invasion, and lymph node metastasis. Our previous study demonstrated that CCR7 overexpressed in non-small cell lung cancer (NSCLC) and had close relationship with tumor invasion and lymph node metastasis. However, the molecular mechanism of CCR7 promoting invasion of human NSCLC cells is still unclear. In this study, we demonstrated that human lung adenocarcinoma A549 cells treated with recombinant human CCL19 could obviously upregulate the expression of Sp1 and heparanase at both the mRNA and protein levels. After blockage of CCR7, Sp1 and heparanase expressions were inhibited. Following inhibition of Sp1, heparanase expression was downregulated. The analysis showed the promoter region of heparanase gene containing a number of potential sp1 binding sites (5'-GGGGC-3'). Chromatin immunoprecipitation analysis demonstrated that Sp1 could bind to the heparanase promoter. Cell invasion assays showed that the invasion ability of A549 cells was increased with CCL19 incubation compared to the control cells. These results suggested that CCL19/CCR7 may upregulate the expression of heparanase via Sp1 and contribute to the invasion of A549 cells.