Regorafenib induces damage-associated molecular patterns, cancer cell death and immune modulatory effects in a murine triple negative breast cancer model.

Damage associated molecular patterns (DAMPs), including calreticulin (CRT) exposure, high-mobility group box 1 protein (HMGB1) elevation, and ATP release, characterize immunogenic cell death (ICD) and may play a role in cancer immunotherapy. Triple negative breast cancer (TNBC) is an immunogenic subtype of breast cancer with higher lymphocyte infiltration. Here, we found that regorafenib, a multi-target angiokinase inhibitor previously known to suppress STAT3 signaling, induced DAMPs and cell death in TNBC cells. Regorafenib induced the expression of HMGB1 and CRT, and the release of ATP. Regorafenib-induced HMGB1 and CRT were attenuated following STAT3 overexpression. In a 4T1 syngeneic murine model, regorafenib treatment increased HMGB1 and CRT expression in xenografts, and effectively suppressed 4T1 tumor growth. Immunohistochemical staining revealed increased CD4+ and CD8+ tumor-infiltrating T cells in 4T1 xenografts following regorafenib treatment. Regorafenib treatment or programmed death-1 (PD-1) blockade using anti-PD-1 monoclonal antibody reduced lung metastasis of 4T1 cells in immunocompetent mice. While regorafenib increases the proportion of MHC II high expression on dendritic cells in mice with smaller tumors, the combination of regorafenib and PD-1 blockade did not show a synergistic effect on anti-tumor activity. These results suggest that regorafenib induces ICD and suppresses tumor progression in TNBC. It should be carefully evaluated when developing a combination therapy with an anti-PD-1 antibody and a STAT3 inhibitor.

One-dimensional van der Waals heterostructures: Growth mechanism and handedness correlation revealed by nondestructive TEM.

We recently synthesized one-dimensional (1D) van der Waals heterostructures in which different atomic layers (e.g., boron nitride or molybdenum disulfide) seamlessly wrap around a single-walled carbon nanotube (SWCNT) and form a coaxial, crystalized heteronanotube. The growth process of 1D heterostructure is unconventional-different crystals need to nucleate on a highly curved surface and extend nanotubes shell by shell-so understanding the formation mechanism is of fundamental research interest. In this work, we perform a follow-up and comprehensive study on the structural details and formation mechanism of chemical vapor deposition (CVD)-synthesized 1D heterostructures. Edge structures, nucleation sites, and crystal epitaxial relationships are clearly revealed using transmission electron microscopy (TEM). This is achieved by the direct synthesis of heteronanotubes on a CVD-compatible Si/SiO2 TEM grid, which enabled a transfer-free and nondestructive access to many intrinsic structural details. In particular, we have distinguished different-shaped boron nitride nanotube (BNNT) edges, which are confirmed by electron diffraction at the same location to be strictly associated with its own chiral angle and polarity. We also demonstrate the importance of surface cleanness and isolation for the formation of perfect 1D heterostructures. Furthermore, we elucidate the handedness correlation between the SWCNT template and BNNT crystals. This work not only provides an in-depth understanding of this 1D heterostructure material group but also, in a more general perspective, serves as an interesting investigation on crystal growth on highly curved (radius of a couple of nanometers) atomic substrates.

Light-Induced Dynamic Restructuring of Cu Active Sites on TiO2 for Low-Temperature H2 Production from Methanol and Water.

The structure and configuration of reaction centers, which dominantly govern the catalytic behaviors, often undergo dynamic transformations under reaction conditions, yet little is known about how to exploit these features to favor the catalytic functions. Here, we demonstrate a facile light activation strategy over a TiO2-supported Cu catalyst to regulate the dynamic restructuring of Cu active sites during low-temperature methanol steam reforming. Under illumination, the thermally deactivated Cu/TiO2 undergoes structural restoration from inoperative Cu2O to the originally active metallic Cu caused by photoexcited charge carriers from TiO2, thereby leading to substantially enhanced activity and stability. Given the low-intensity solar irradiation, the optimized Cu/TiO2 displays a H2 production rate of 1724.1 µmol g-1 min-1, outperforming most of the conventional photocatalytic and thermocatalytic processes. Taking advantages of the strong light-matter-reactant interaction, we achieve in situ manipulation of the Cu active sites, suggesting the feasibility for real-time functionalization of catalysts.

Plasma cell-free tumor DNA, PIK3CA and TP53 mutations predicted inferior endocrine-based treatment outcome in endocrine receptor-positive metastatic breast cancer.

PURPOSE: How to factor both tumor burden and oncogenic genomic mutations as variables to predict the outcome of endocrine-based therapy (ET) in ER-positive/HER2-negative metastatic breast cancer patients (MBC) remains to be explored. METHOD: Blood samples prospectively collected from 163 ER-positive/HER2-negative female MBC patients, before ET, were used for cell-free tumor DNA (cfDNA) analysis. cfDNA was subjected to next-generation sequencing (NGS) to interrogate oncogenic PIK3CA hotspot and TP53 DNA-binding domain (DBD) mutations, including single nucleotide variants (SNVs) or small insertions and deletions (InDels). The variant calling threshold was set at 0.5%. Progression-free survival (PFS) was measured from the start of the ET treatment to the time of disease progression of the same treatment regimen. RESULTS: Overall, the median PFS was 8.3 months (95% CI 5.7-11.1 months). The median cfDNA was 38.5 ng (range 4.4-1935 ng). The proportion of patients with PIK3CA and TP53 alterations were 25.1 and 15.3%, respectively. Patients with high total cfDNA (HR 1.74, p = 0.003), PIK3CA mutation (HR 1.74, p = 0.007), and TP53 mutation (HR 1.64, p = 0.047) in liquid biopsy conferred worse outcome after ET. Even for patients with low tumor burden, the detrimental effect of PIK3CA or TP53 mutation remained significant (p < 0.001). For patients with either PIK3CA (p < 0.001) or TP53 mutation (p = 0.004), there was significant positive correlation between allele frequency (AF) and total cfDNA. CONCLUSION: After adjustment of cfDNA level, PIK3CA and TP53 mutations observed in liquid biopsy exerted detrimental effects on the outcome of ET-based regimens. The AF of PIK3CA or TP53 may be a surrogate marker for PFS.

An Emerging Family of Piezocatalysts: 2D Piezoelectric Materials.

Piezocatalysis is an emerging technique that holds great promise for the conversion of ubiquitous mechanical energy into electrochemical energy through piezoelectric effect. However, mechanical energies in natural environment (such as wind energy, water flow energy, and noise) are typically tiny, scattered, and featured with low frequency and low power. Therefore, a high response to these tiny mechanical energies is critical to achieving high piezocatalytic performance. In comparison to nanoparticles or 1D piezoelectric materials, 2D piezoelectric materials possess characteristics such as high flexibility, easy deformation, large surface area, and rich active sites, showing more promise in future for practical applications. In this review, state-of-the-art research progresses on 2D piezoelectric materials and their applications in piezocatalysis are provided. First, a detailed description of 2D piezoelectric materials are offered. Then a comprehensive summary of the piezocatalysis technique is presented and examines the piezocatalysis applications of 2D piezoelectric materials in various fields, including environmental remediation, small-molecule catalysis, and biomedicine. Finally, the main challenges and prospects of 2D piezoelectric materials and their applications in piezocatalysis are discussed. It is expected that this review can fuel the practical application of 2D piezoelectric materials in piezocatalysis.

High-valent Cu(III)-CF3 compound-mediated esterification reaction.

Cu(III)-CF3 compounds are reported herein as novel coupling reagents to mediate ester synthesis from carboxyl acids and alcohols/phenols. Carboxylic acids are transformed to trifluoromethyl ester and acyl fluoride activated species that interact with each other. The broad substrate scope and late-stage application of this method are demonstrated. This study opens up new opportunities to develop interesting reactions using Cu(III)-CF3 compounds without transferring a CF3 group to the products.

The relationship between longer leukocyte telomeres and dNCR in non-cardiac surgery patients: a retrospective analysis.

BACKGROUND: Cognitive decline following surgery is a common concern among elderly individuals. Leukocyte telomere length (LTL) can be assessed as a biological clock connected to an individual lifespan. However, the mechanisms causing this inference are still not fully understood. As a result of this, LTL has the potential to be useful as an aging-related biomarker for assessing delayed neurocognitive recovery (dNCR) and related diseases. METHODS: For this study, 196 individuals over 60 who were scheduled due to major non-cardiac surgical operations attended neuropsychological testing before surgery, followed by additional testing one week later. The finding of dNCR was based on a measured Z-score ≤ -1.96 on two or more separate tests. The frequency of dNCR was presented as the primary outcome of the study. Secondly, we evaluated the association between dNCR and preoperative LTL. RESULTS: Overall, 20.4% [40/196; 95% confidence interval (CI), 14.7-26.1%] of patients exhibited dNCR 1-week post-surgery. Longer LTL was identified as a predictor for the onset of early cognitive impairment resulting in postoperative cognitive decline [odds ratio (OR), 14.82; 95% CI, 4.01-54.84; P < 0.001], following adjustment of age (OR, 12.33; 95% CI, 3.29-46.24; P < 0.001). The dNCR incidence based on LTL values of these patients, the area under the receiver operating characteristic (ROC) curve was 0.79 (95% CI, 0.722-0.859; P < 0.001). At an optimal cut-off value of 0.959, LTL values offered respective specificity and sensitivity values of 64.7% and 87.5%. CONCLUSIONS: In summary, the current study revealed that the incidence of dNCR was strongly associated with prolonged LTL. Furthermore, this biomarker could help identify high-risk patients and offer insight into the pathophysiology of dNCR.

Volatile Organic Compounds of Bacillus pumilus Strain S1-10 Exhibit Fumigant Activity Against Meloidogyne incognita.

Root-knot nematodes (RKNs) are highly specialized parasites that cause significant yield losses worldwide. In this study, we isolated Bacillus pumilus strain S1-10 from the rhizosphere soil of Zingiber officinale Rosc. plants and evaluated its fumigant activity against Meloidogyne incognita. S1-10 exhibited a strong repellent effect on second-stage juveniles (J2s) of M. incognita, and in vitro assays indicated that S1-10 volatile organic compounds (VOCs) suppressed J2 activity and egg hatching. Under greenhouse conditions, 71 and 79% reductions of nematodes and eggs were detected on plants treated with S-10 VOCs compared with controls. Ten VOCs were identified through gas chromatography and mass spectrometry (GC-MS), of which 2-(methylamino)-ethanol (2-ME) had strong fumigant activity against J2s of M. incognita, with an LC50 value of 1.5 mM at 12 h. These results indicate that S1-10 represents a potential novel biocontrol agent for RKNs.

Clarification of Faber series and related applications to complex variable methods in two-dimensional elasticity.

Faber series are used extensively in the application of complex variable methods to two-dimensional elasticity theory, for example, in the mechanical analysis of composite materials where Faber series representations of complex potentials lead to convenient expressions for the corresponding displacement and stress distributions. In many cases, the use of the Faber series is combined with conformal mapping techniques which "transfer" a boundary value problem defined in the elastic body (physical plane) to a simpler problem posed in an imaginary plane characterized by the conformal mapping. In several instances in the literature, however, little attention has been paid to the domain of definition of the Faber series in the imaginary plane leading often to misunderstandings and erroneous conclusions regarding the concept and feasibility of the use of the Faber series. In this paper, we present a thorough and rigorous examination of the representation of the Faber series in both the physical (occupied by the material) and imaginary (defined by the conformal mapping) plane. In addition, we show that replacing a truncated Faber series by a truncated Taylor series does not induce any additional errors in the numerical analysis of the corresponding boundary value problem. We anticipate that the discussion in this paper will help clarify any existing misinterpretations regarding the application of the Faber series and help further extend their use to a range of problems in composite mechanics.

Interfering B cell receptor signaling via SHP-1/p-Lyn axis shows therapeutic potential in diffuse large B-cell lymphoma.

BACKGROUND: Diffuse large B cell lymphoma (DLBCL) is an aggressive and molecularly heterogeneous non-Hodgkin's lymphoma. The B cell receptor (BCR) signaling pathway in DLBCL emerges as a new drug target. Protein phosphatase SHP-1 negatively regulates several oncogenic tyrosine kinases and plays a tumor suppressive role. METHODS: The direct SHP-1 agonists were used to evaluate the potential therapeutic implication of SHP-1 in DLBCL. Immunohistochemical staining for SHP-1 was quantified by H-score. The SHP-1 phosphatase activity was determined using tyrosine phosphatase assay. In vitro studies, including MTT, western blot analysis and cell apoptosis, were utilized to examined biological functions of SHP-1. RESULTS: Oral administration of SHP-1 agonist showed the potent anti-tumor effects compared to a selective Bruton's tyrosine kinase (BTK) inhibitor ibrutinib in mice bearing U2932 xenografts. SHP-1 agonist increased SHP-1 activity as well as downregulated p-Lyn in vivo. Here, we demonstrated that immunohistochemical staining for SHP-1 expression was positive in 76% of DLBCL samples. SHP-1 agonist exerted anti-proliferative and apoptotic effects compared with ibrutinib in DLBCL cells. Mechanistically, SHP-1 agonist decreased BCR signaling, especially p-Lyn, and led to apoptosis. CONCLUSIONS: These data suggest that SHP-1 negatively regulates phosphorylation of Lyn, and targeting SHP-1/p-Lyn using SHP-1 agonist has therapeutic potential for treatment of DLBCL.

Mechanistic Study of Interfacial Modification for Stable Zn Anode Based on a Thin Separator.

The interface plays a pivotal role in stabilizing metal anode. Extensive studies have been made but systematic research is lacking. In this study, preliminary studies are conducted to explore the prime conditions of interfacial modification to approach the practical requirements. Critical factors including reaction kinetics, transport rate, and modulus are identified to affect the Zn anode morphology significantly. The fundamental principle to enhance the Zn anode stability is systematically studied using the TEMPO-oxidized cellulose nanofiber (TOCNF) coating layer with thin a separator. Its advantageous mechanical properties buffer the huge volume variation. The existence of hydrophilic TOCNF in the Zn anode interface enhances the mass transfer process and alters the Zn2+ distribution with a record high double-layer capacitance (390 uF cm-2 ). With the synergetic effect, the modified Zn anode works stably under 5 mA cm-2 with a thin nonwoven paper as the separator (thickness 113 µm). At an ultra-high current density of 10 mA cm-2 , this coated anode cycles for more than 300 h. This strategy shows an immense potential to drive the Zn anode forward toward practical applications.

Effect of oxygen partial pressure on the performance of homojunction amorphous In-Ga-Zn-O thin-film transistors.

In this study, the homojunction thin-film transistors (TFTs) with amorphous indium gallium zinc oxide (a-IGZO) as active channel layers and source/drain electrodes were fabricated by RF magnetron sputtering. The effect of oxygen partial pressure on the phase, microstructure, optical and electrical properties of IGZO thin films was investigated. The results showed that amorphous IGZO thin films always exhibit a high transmittance above 90% and wide band gaps of around 3.9 eV. The resistivity increases as the IGZO thin films are deposited at a higher oxygen partial pressure due to the depletion of oxygen vacancies. In addition, the electrical behaviors in homojunction IGZO TFTs were analyzed. When the active channel layers were deposited with an oxygen partial pressure of 1.96%, the homojunction IGZO TFTs exhibited optimal transfer and output characteristics with a field-effect mobility of 13.68 cm2V-1s-1. Its sub-threshold swing, threshold voltage and on/off ratio are 0.6 V/decade, 0.61 V and 107, respectively.

Effect of initial COVID-19 outbreak during first trimester on pregnancy outcome in Wuxi, China.

BACKGROUND: A hospital-based retrospective study was conducted to examine the effect of initial COVID-19 outbreak during first trimester on pregnancy outcome in Wuxi, China. METHODS: Women who delivered children at our hospital during June 2020 to July 2020 (control group), and October 2020 to December 2020 (exposure group) were recruited in the present study. All of the participants were not infected with COVID-19. The last menstrual period (LMP) of the exposure group was between January 24th, 2020 and March 12th, 2020, whilst in the control group, the LMP was between May 12th and October 31st, 2019. RESULTS: There were 1,456 women in the exposure group and 1,816 women in the control group. Women in the exposure group were more susceptible to hypertension during pregnancy (HDP, P = 0.004, OR[95%CI] = 1.90[1.22-2.95]) and gestational diabetes mellitus (GDM, P = 0.008, OR[95%CI] = 1.31[1.08-1.60]) compared to those in the control group. Mothers diagnosed with HDP were more likely to deliver premature infants, leading to a higher rate of low birth weight (all P < 0.05). The other common outcomes of pregnancy showed no statistical differences between the two groups. CONCLUSIONS: The initial COVID-19 outbreak might increase the incidence rates of HDP and GDM among pregnant women whose first trimesters were during that period, resulting in higher percentages of premature delivery and low birth weight. These results should be confirmed by studies from other hospitals or cities.

Rising temperature contributed to the outbreak of a macrozooplankton Creseis acicula by enhancing its feeding and assimilation for algal food nearby the coastal Daya Bay Nuclear Power Plant.

An outbreak of a macrozooplankton Creseis acicula occurred in the summer of 2020 nearby the Daya Bay Nuclear Power Plant located on the coast of the Daya Bay in the South China Sea. The outbreaks of C. acicula often threaten human health, the marine environment, and other human activities including the safe operation of coastal nuclear power plants. Seawater temperature has been suggested as an important factor influencing such outbreaks. However, the underlying mechanisms through which temperature influences C. acicula remains unknown. Here, we studied the effects of temperature on the ingestion and assimilation of algal food by feeding radiocarbon-labeled algae Chlorella sp. at simulated field temperatures (19-31 °C) to C. acicula collected during the outbreak in the Daya Bay. We also quantified the allocation of the food carbon to dissolved organic carbon (DOC), CO2, and fecal pellets. The results showed that the zooplankton during the same feeding time ingested doubled or tripled algal food at higher temperatures, and it produced and released significantly more DOC, CO2, and fecal pellets with more ingested food carbon. Meanwhile, the assimilation efficiency for the ingested food carbon slightly increased from 48% to 54% with rising temperature. As a result, higher assimilation rates indicating faster growth of C. acicula were observed at higher temperatures. In addition, the high activation energy of 0.908 eV indicated that the assimilation rate was very sensitive to temperature rising. Our results show that relatively rising temperature can enhance C. acicula's ingestion and assimilation rates for algal food, benefit its growth and metabolism, and contribute to its outbreak. This study provides a mechanistic interpretation for the relationship between rising temperature and the outbreaks of C. acicula and suggests that such outbreaks may occur more frequently and widely in the warming ocean.

Neoadjuvant afatinib with paclitaxel for triple-negative breast cancer and the molecular characteristics in responders and non-responders.

BACKGROUND: The prognosis of triple-negative breast cancer (TNBC) is worse and a major proportion of TNBC expresses epidermal growth factor receptor (EGFR). Afatinib can inhibit EGFR signal pathway; however, its treatment effect for TNBC is unknown. Thus, we aimed to assess the efficacy and biomarkers of afatinib in combination with paclitaxel in a neoadjuvant setting. METHODS: Patients with stage II to III TNBC were enrolled. They received 40 mg of afatinib daily for 14 days, followed by daily afatinib and weekly paclitaxel (80 mg/m2) every 21 days for four to six cycles. To explore the mechanisms of responsiveness and non-responsiveness, 409 cancer-associated genes were sequenced. RESULTS: Twenty-one patients were enrolled and one patient achieved a complete clinical response; however, a 2 mm residual tumor was noted in the surgical specimen. Overall, 33.0% patients were responders. Fifteen patients received molecular testing. No activated mutation of EGFR or Her2 were found. Activated PI3K or JAK2 pathway were trended to associate with non-responder (p = 0.057). Mutation of homologous recombination (HR) genes were correlated with non-responsiveness (p = 0.005). Seven patients did not have altered PI3K, JAK2 or HR pathway; six (85.7%) of them were responder. Patients with the amplified DAXX gene was associated with a favorable trend of response (p = 0.109). CONCLUSION: Adding afatinib to neoadjuvant paclitaxel generated a modest effect in TNBC. Exploratory molecular analysis suggested that activated PI3K, JAK2 pathways and mutation of HR genes were associated with therapeutic non-responsiveness, and amplification of DAXX genes was associated with responsiveness to afatinib in combination with paclitaxel.

New stilbenes and phenolic constituents from the rhizomes of Belamcanda chinensis.

A pair of stilbenes with γ-lactam unit [(+)-1 and (-)-1], a new phenolic glucoside (2), and a new isoflavone glucoside (3), together with two known compounds (4-5) were isolated from the rhizomes of Belamcanda chinensis. The chemical structures of the undescribed compounds were elucidated on the basis of detailed spectroscopic analyses. Compounds 1, 4, and 5 (10 µM) exhibited anti-inflammatory activities with inhibition rates of 30.46%, 60.34%, and 37.91%, respectively, against the NF-κB signaling pathway.

Quantitative Proteomic Analysis Reveals the Key Molecular Events Driving Phaeocystis globosa Bloom and Dissipation.

Phaeocystis globosa is a marine-bloom-forming haptophyte with a polymorphic life cycle alternating between free-living cells and a colonial morphotype, that produces high biomass and impacts ecological structure and function. The mechanisms of P. globosa bloom formation have been extensively studied, and various environmental factors are believed to trigger these events. However, little is known about the intrinsic biological processes that drive the bloom process, and the mechanisms underlying P. globosa bloom formation remain enigmatic. Here, we investigated a P. globosa bloom occurring along the Chinese coast and compared the proteomes of in situ P. globosa colonies from bloom and dissipation phases using a tandem mass tag (TMT)-based quantitative proteomic approach. Among the 5540 proteins identified, 191 and 109 proteins displayed higher abundances in the bloom and dissipation phases, respectively. The levels of proteins involved in photosynthesis, pigment metabolism, nitrogen metabolism, and matrix substrate biosynthesis were distinctly different between these two phases. Ambient nitrate is a key trigger of P. globosa bloom formation, while the enhanced light harvest and multiple inorganic carbon-concentrating mechanisms support the prosperousness of colonies in the bloom phase. Additionally, colonies in the bloom phase have greater carbon fixation potential, with more carbon and energy being fixed and flowing toward the colonial matrix biosynthesis. Our study revealed the key biological processes underlying P. globosa blooms and provides new insights into the mechanisms behind bloom formation.

Effects of individualized positive end-expiratory pressure combined with recruitment maneuver on intraoperative ventilation during abdominal surgery: a systematic review and network meta-analysis of randomized controlled trials.

Low tidal volume ventilation strategy may lead to atelectasis without proper positive end-expiratory pressure (PEEP) and recruitment maneuver (RM) settings. RM followed by individualized PEEP was a new method to optimize the intraoperative pulmonary function. We conducted a systematic review and network meta-analysis of randomized clinical trials to compare the effects of individualized PEEP + RM on intraoperative pulmonary function and hemodynamic with other PEEP and RM settings. The primary outcomes were intraoperative oxygenation index and dynamic compliance, while the secondary outcomes were intraoperative heart rate and mean arterial pressure. In total, we identified 15 clinical trials containing 36 randomized groups with 3634 participants. Ventilation strategies were divided into eight groups by four PEEP (L: low, M: moderate, H: high, and I: individualized) and two RM (yes or no) settings. The main results showed that IPEEP + RM group was superior to all other groups regarding to both oxygenation index and dynamic compliance. LPEEP group was inferior to LPEEP + RM, MPEEP, MPEEP + RM, and IPEEP + RM in terms of oxygenation index and LPEEP + RM, MPEEP, MPEEP + RM, HPEEP + RM, IPEEP, and IPEEP + RM in terms of dynamic compliance. All comparisons were similar for secondary outcomes. Our analysis suggested that individualized PEEP and RM may be the optimal low tidal volume ventilation strategy at present, while low PEEP without RM is not suggested.

A Case of Oncocytic Adrenal Cortical Neoplasm with Uncertain Malignant Potential Turned Out to Be Oncocytic Adrenal Cortical Carcinoma with Distant Metastasis: Could Pathology Do Better Initially?

Oncocytic adrenal cortical neoplasms are rare cases and are divided into oncocytoma, oncocytic neoplasms of uncertain malignant potential and oncocytic adrenal cortical carcinomas, based on the Lin-Weiss-Bisceglia (LWB) histological system adopted in the current World Health Organization (WHO). We reported a 42-year-old female diagnosed with an oncocytic neoplasm of uncertain malignant potential initially, which turned out to be a carcinoma owing to distant metastasis to the scalp and lung. To our knowledge, this is the first published case of oncocytic adrenal cortical carcinoma with scalp metastasis. This case also highlights the limitation of the current diagnostic algorithm and emphasizes the importance of two parameters (PHH3 and Ki-67) for determining the malignant potential of oncocytic adrenal cortical neoplasms.

Exfoliated Ferrierite-Related Unilamellar Nanosheets in Solution and Their Use for Preparation of Mixed Zeolite Hierarchical Structures.

Direct exfoliation of layered zeolites into solutions of monolayers has remained unresolved since the 1990s. Recently, zeolite MCM-56 with the MWW topology (layers denoted mww) has been exfoliated directly in high yield by soft-chemical treatment with tetrabutylammonium hydroxide (TBAOH). This has enabled preparation of zeolite-based hierarchical materials and intimate composites with other active species that are unimaginable via the conventional solid-state routes. The extension to other frameworks, which provides broader benefits, diversified activity, and functionality, is not routine and requires finding suitable synthesis formulations, viz. compositions and conditions, of the layered zeolites themselves. This article reports exfoliation and characterization of layers with ferrierite-related structure, denoted bifer, having rectangular lattice constants like those of the FER and CDO zeolites, and thickness of approximately 2 nm, which is twice that of the so-called fer layer. Several techniques were combined to prove the exfoliation, supported by simulations: AFM; in-plane, in situ, and powder X-ray diffraction; TEM; and SAED. The results confirmed (i) the structure and crystallinity of the layers without unequivocal differentiation between the FER and CDO topologies and (ii) uniform thickness in solution (monodispersity), ruling out significant multilayered particles and other impurities. The bifer layers are zeolitic with Brønsted acid sites, demonstrated catalytic activity in the alkylation of mesitylene with benzyl alcohol, and intralayer pores visible in TEM. The practical benefits are demonstrated by the preparation of unprecedented intimately mixed zeolite composites with the mww, with activity greater than the sum of the components despite high content of inert silica as pillars.