Study on Mechanical and Electrical Properties of High Content CNTs/Cu Composites.

It is expected that composites made of carbon nanotubes (CNT) and copper (Cu) display both mechanical and electrical properties, but the low damage dispersion and high-quality composite of high-content CNTs have always been research difficulties. In this paper, high-content CNTs/Cu composites were prepared. The effects of the sintering method, sintering temperature, directional rolling and the CNTs' content on the relative density, hardness and electrical conductivity of the composites were studied. The uniform dispersion of high-content CNTs in Cu matrix was achieved by ball milling, sintering and rolling, and the processes did not cause more damage to the CNTs. The properties of composites prepared by spark plasma sintering (SPS) and vacuum hot pressing sintering (HPS) were compared, and the optimum process parameters of SPS were determined. When the CNTs' content is 2 wt.%, the hardness is 134.9 HBW, which is still 2.3 times that of pure Cu, and the conductivity is the highest, reaching 78.4%IACS. This study provides an important reference for the high-quality preparation and performance evaluation of high-content CNTs/Cu composites.

The tripartite motif-containing 24 is a multifunctional player in human cancer.

Tripartite motif-containing 24 (TRIM24), also known as transcriptional intermediary factor 1α (TIF1α), is the founding member of TIF1 family. Recent evidence indicates that aberrant expression of TRIM24, functions as an oncogene, is associated with poor prognosis across various cancer types. TRIM24 exhibits a multifaceted structure comprising an N-terminal TRIM region with a RING domain, B-box type 1 and type 2 domains, and a coiled-coil region, as well as a C-terminal plant-homeodomain (PHD)-bromodomain. The bromodomain serves as a 'reader' of epigenetic histone marks, regulating chromatin structure and gene expression by linking associated proteins to acetylated nucleosomal targets, thereby controlling transcription of genes. Notably, bromodomains have emerged as compelling targets for cancer therapeutic development. In addition, TRIM24 plays specialized roles as a signal transduction molecule, orchestrating various cellular signaling cascades in cancer cells. Herein, we review the recent advancements in understanding the functions of TRIM24, and demonstrate the research progress in utilizing TRIM24 as a target for cancer therapy.

Molecular mechanisms of PTEN in atherosclerosis: A comprehensive review.

Atherosclerosis is a chronic inflammatory disease of the arterial wall caused by an imbalance of lipid metabolism and a maladaptive inflammatory response. A variety of harmful cellular changes associated with atherosclerosis include endothelial dysfunction, the migration of circulating inflammatory cells to the arterial wall, the production of proinflammatory cytokines, lipid buildup in the intima, local inflammatory responses in blood vessels, atherosclerosis-associated apoptosis, and autophagy. PTEN inhibits the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT)/mammalian target of rapamycin (mTOR) pathway through its lipid phosphatase activity. Previous studies have shown that PTEN is closely related to atherosclerosis. This article reviews the role of PTEN in atherosclerosis from the perspectives of autophagy, apoptosis, inflammation, proliferation, and angiogenesis.

Safety of risdiplam in spinal muscular atrophy patients after short-term treatment with nusinersen.

INTRODUCTION/AIMS: Following the approval of risdiplam, there are more possibilities for disease-modifying therapy (DMT) in children with spinal muscular atrophy (SMA). Non-treatment-naïve subjects with SMA involved in the JEWELFISH study, designed to evaluate the safety and tolerability of risdiplam, were required to undergo a washout period before receiving risdiplam. This study aims to investigate the safety of administering risdiplam in patients within 90 days of receiving treatment with nusinersen. METHODS: Data were collected on SMA patients who had undergone treatment with nusinersen, and who then received risdiplam within 90 days of their last dose of nusinersen, including demographic characteristics, information on treatment with nusinersen and risdiplam, adverse events, and laboratory assessments in a follow-up period of 90 days, presented as median (range). RESULTS: A total of 15 children with SMA were reported, including 8 males and 7 females. The median number of doses of previous nusinersen treatment received was 8 (6-17) doses, and the median age at first risdiplam treatment was 4.3 (1.9-11.2) years. Specifically, 8 children received risdiplam 30 days or less after their most recent nusinersen treatment, 2 at 31-60 days after nusinersen, and 5 at 61-89 days post-nusinersen. Adverse events of pyrexia, pneumonia, vomiting and rash were reported in 4 patients. DISCUSSION: Our study showed good safety data on patients who received risdiplam following nusinersen within the washout period of 90 days. This supplements the JEWELFISH study in the era of DMT, providing additional guidance for clinicians, but additional data from other centers is needed.

Dynamic evolution of MADS-box genes in extant ferns via large-scale phylogenomic analysis.

Introduction: Several studies of MADS-box transcription factors in flowering plants have been conducted, and these studies have indicated that they have conserved functions in floral organ development; MIKC-type MADS-box genes has been proved to be expanded in ferns, however, few systematic studies of these transcription factors have been conducted in non-seed plants. Although ferns and seed plants are sister groups, they exhibit substantial morphological differences. Methods: Here, we clarified the evolution of MADS-box genes across 71 extant fern species using available transcriptome, genome, and gene expression data. Results: We obtained a total of 2,512 MADS-box sequences, ranging from 9 to 89 per species. The most recent common ancestor (MRCA) of ferns contained approximately three type I genes and at least 5-6 type II MADS-box genes. The domains, motifs, expression of type I and type II proteins, and the structure of the both type genes were conserved in ferns as to other land plants. Within type II genes, MIKC*-type proteins are involved in gametophyte development in ferns; MIKCC-type proteins have broader expression patterns in ferns than in seed plants, and these protein sequences are likely conserved in extant seed plants and ferns because of their diverse roles in diploid sporophyte development. More than 90% of MADS-box genes are type II genes, and MIKCC genes, especially CRM1 and CRM6-like genes, have undergone a large expansion in leptosporangiate ferns; the diverse expression patterns of these genes might be related to the fuctional diversification and increased complexity of the plant body plan. Tandem duplication of CRM1 and CRM6-like genes has contributed to the expansion of MIKCC genes. Conclusion or Discussion: This study provides new insights into the diversity, evolution, and functions of MADS-box genes in extant ferns.

Genome-wide data reveal bi-direction and asymmetrical hybridization origin of a fern species Microlepia matthewii.

Introduction: Natural hybridization is common and plays a crucial role in driving biodiversity in nature. Despite its significance, the understanding of hybridization in ferns remains inadequate. Therefore, it is imperative to study fern hybridization to gain a more comprehensive understanding of fern biodiversity. Our study delves into the role of hybridization in shaping fern species, employing Microlepia matthewii as a case study to investigate its origins of hybridization. Methods: We performed double digest Genotyping-by-sequencing (dd-GBS) on M. matthewii and its potential parent species, identifying nuclear and chloroplast SNPs. Initially, nuclear SNPs were employed to construct the three cluster analysis: phylogenetic tree, principal component analysis, and population structure analysis. Subsequently, to confirm whether the observed genetic mixture pattern resulted from hybridization, we utilized two methods: ABBA-BABA statistical values in the D-suite program and gene frequency covariance in the Treemix software to detect gene flow. Finally, we employed chloroplast SNPs to construct a phylogenetic tree, tracing the maternal origin. Results and discussion: The analysis of the nuclear SNP cluster revealed that M. matthewii possesses a genetic composition that is a combination of M. hancei and M. calvescens. Furthermore, the analysis provided strong evidence of significant gene flow signatures from the parental species to the hybrid, as indicated by the two gene flow analyses. The samples of M. matthewii cluster separately with M. hancei or M. calvescens on the chloroplast systematic tree. However, the parentage ratio significantly differs from 1:1, suggesting that M. matthewii is a bidirectional and asymmetrical hybrid offspring of M. hancei and M. calvescens.

Changes in productivity partitioning induced by precipitation extremes increase inaccuracy of grassland carbon estimation.

The fraction of net primary productivity (NPP) allocated to belowground organs (fBNPP) in grasslands is a critical parameter in global carbon cycle models; moreover, understanding the effect of precipitation changes on this parameter is vital to accurately estimating carbon sequestration in grassland ecosystems. However, how fBNPP responds to temporal precipitation changes along a gradient from extreme drought to extreme wetness, remains unclear, mainly due to the lack of long-term data of belowground net primary productivity (BNPP) and the fact that most precipitation experiments did not have a gradient from extreme drought to extreme wetness. Here, by conducting both a precipitation gradient experiment (100-500 mm) and a long-term observational study (34 years) in the Inner Mongolia grassland, we showed that fBNPP decreased linearly along the precipitation gradient from extreme drought to extreme wetness due to stronger responses in aboveground NPP to drought and wet conditions than those of BNPP. Our further meta-analysis in grasslands worldwide also indicated that fBNPP increased when precipitation decreased, and the vice versa. Such a consistent pattern of fBNPP response suggests that plants increase the belowground allocation with decreasing precipitation, while increase the aboveground allocation with increasing precipitation. Thus, the linearly decreasing response pattern in fBNPP should be incorporated into models that forecast carbon sequestration in grassland ecosystems; failure to do so will lead to underestimation of the carbon stock in drought years and overestimation of the carbon stock in wet years in grasslands.

Analytical validation of the amplification refractory mutation system polymerase chain reaction-capillary electrophoresis assay to diagnose spinal muscular atrophy.

OBJECTIVES: Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by homozygous deletion and compound heterozygous mutations in survival motor neuron 1 (SMN1), with severity tied to the copy number of survival motor neuron 2 (SMN2). This study aimed to develop a rapid and comprehensive method for the diagnosis of SMA. METHODS: A total of 292 children with clinically suspected SMA and 394 family members were detected by the amplification refractory mutation system polymerase chain reaction-capillary electrophoresis (ARMS-PCR-CE) method, which targeted 19 reported mutations, and the results were compared with those in multiplex ligation-dependent probe amplification (MLPA). Individuals with identified point mutations were further confirmed by SMN1 long-range PCR and Sanger sequencing. RESULTS: A total of 202 children with SMA, 272 carriers, and 212 normal individuals were identified in this study. No difference was found in the R-value distribution of exons 7 and 8 in SMN1 and SMN2 among these cohorts, with coefficients of variation consistently below 0.08. To detect exon 7 and 8 copy numbers in SMN1 and SMN2, the ARMS-PCR-CE results were concordant with those of MLPA. Approximately 4.95 % (10/202) of the study patients had compound heterozygous mutations. CONCLUSIONS: The ARMS-PCR-CE assay is a comprehensive, rapid, and accurate diagnostic method for SMA that simultaneously detects copy numbers of exons 7 and 8 in SMN1/SMN2, as well as 19 point mutations in SMN1 and 2 enhancers in SMN2. This approach can effectively reduce the time frame for diagnosis, facilitating early intervention and preventing birth defects.

Stepwise Construction of MoS2@CoAl-LDH/NF 3D Core-Shell Nanoarrays with High Hole Mobility for High-Performance Asymmetric Supercapacitors.

Supercapacitors (SCs) have received widespread attention as excellent energy storage devices, and the design of multicomponent electrode materials and the construction of ingenious structures are the keys to enhancing the performance of SCs. In this paper, MoS2 nanorods were used as the carrier structure to induce the anchoring of CoAl-LDH nanosheets and grow on the surface of nickel foam (NF) in situ, thus obtaining a uniformly distributed MoS2 nanorod@CoAl-LDH nanosheet core-shell nanoarray material (MoS2@CoAl-LDH/NF). On the one hand, the nanorod-structured MoS2 as the core provides high conductivity and support, accelerates electron transfer, and avoids agglomeration of CoAl-LDH nanosheets. On the other hand, CoAl-LDH nanosheet arrays have abundant interfacially active sites, which accelerate the electrolyte penetration and enhance the electrochemical activity. The synergistic effect of the two components and the unique core-shell nanostructure give MoS2@CoAl-LDH/NF a high capacity (14,888.8 mF cm-2 at 2 mA cm-2) and long-term cycling performance (104.4% retention after 5000 charge/discharge cycles). The integrated MoS2@CoAl-LDH/NF//AC device boasts a voltage range spanning from 0 to 1.5 V, achieving a peak energy density of 0.19 mW h cm-2 at 1.5 mW cm-2. Impressively, it maintains a capacitance retention rate of 84.6% after enduring 10,000 cycles, demonstrating exceptional durability and stability.

Transcriptomic-metabolomic analysis reveals the effect of copper toxicity on fermentation properties in Saccharomyces cerevisiae.

Copper is one of the unavoidable heavy metals in wine production. In this study, the effects on fermentation performance and physiological metabolism of Saccharomyces cerevisiae under copper stress were investigated. EC1118 was the most copper-resistant among the six strains. The ethanol accumulation of EC1118 was 26.16-20 mg/L Cu2+, which was 1.90-3.15 times higher than that of other strains. The fermentation rate was significantly reduced by copper, and the inhibition was relieved after 4-10 days of adjustment. Metabolomic-transcriptomic analysis revealed that amino acid and nucleotide had the highest number of downregulated and upregulated differentially expressed metabolites, respectively. The metabolism of fructose and mannose was quickly affected, which then triggered the metabolism of galactose in copper stress. Pathways such as oxidative and organic acid metabolic processes were significantly affected in the early time, resulting in a significant decrease in the amount of carboxylic acids. The pathways related to protein synthesis and metabolism under copper stress, such as translation and peptide biosynthetic process, was also significantly affected. In conclusion, this study analyzed the metabolite-gene interaction network and molecular response during the alcohol fermentation of S. cerevisiae under copper stress, providing theoretical basis for addressing the influence of copper stress in wine production.

Angiopterisnodosipetiolata (Marattiaceae), a new fern species from Yunnan, China.

Angiopterisnodosipetiolata Ting Wang tris, H.F.Chen & Y.H.Yan, a new fern of Marattiaceae, is described and illustrated. Morphologically, A.nodosipetiolata is similar to A.chingii with more than one naked pulvinus on the stipe and numerous jointed hairs on the undersides of the mature pinnae. However, the pinnae of A.nodosipetiolata are lanceolate and can reach up to 4-6 pairs, whereas they are elliptic and occur in 2-3 pairs in A.chingii. Phylogenetic and genetic distance analysis, based on the plastid genomes, also indicates that A.nodosipetiolata is not closely related to A.chingii. Currently, there are ca. 500 mature individuals in Gulinqing Nature Reserve and we suggest A.nodosipetiolata should be categorised as an Endangered (EN) species according to the criteria of IUCN.

Distribution of HPV types among women with HPV-related diseases and exploration of lineages and variants of HPV 52 and 58 among HPV-infected patients in China: A systematic literature review.

To summarize the distribution of types of human papillomavirus (HPV) associated with HPV-related diseases and investigate the potential causes of high prevalence of HPV 52 and 58 by summarizing the prevalence of lineages, sub-lineages, and mutations among Chinese women. We searched PubMed, EMBASE, CNKI, and WanFang from January, 2012 to June, 2023 to identify all the eligible studies. We excluded patients who had received HPV vaccinations. Data were summarized in tables and cloud/rain maps. A total of 102 studies reporting HPV distribution and 15 studies reporting HPV52/HPV58 variants were extracted. Among Chinese women, the top five prevalent HPV types associated with cervical cancer (CC) were HPV16, 18, 58, 52, and 33. In patients with vaginal cancers and precancerous lesions, the most common HPV types were 16 and 52 followed by 58. For women with condyloma acuminatum (CA), the most common HPV types were 11 and 6. In Chinese women with HPV infection, lineage B was the most prominently identified for HPV52, and lineage A was the most common for HPV58. In addition to HPV types 16, which is prevalent worldwide, our findings revealed the unique high prevalence of HPV 52/58 among Chinese women with HPV-related diseases. HPV 52 variants were predominantly biased toward lineage B and sub-lineage B2, and HPV 58 variants were strongly biased toward lineage A and sub-lineage A1. Further investigations on the association between the high prevalent lineage and sub-lineage in HPV 52/58 and the risk of cancer risk are needed. Our findings underscore the importance of vaccination with the nine-valent HPV vaccine in China.

Targeting metabolism to enhance immunotherapy within tumor microenvironment.

Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Like cancer cells, immune cells within the tumor microenvironment or premetastatic niche also undergo extensive metabolic reprogramming, which profoundly impacts anti-tumor immune responses. Numerous evidence has illuminated that immunosuppressive TME and the metabolites released by tumor cells, including lactic acid, Prostaglandin E2 (PGE2), fatty acids (FAs), cholesterol, D-2-Hydroxyglutaric acid (2-HG), adenosine (ADO), and kynurenine (KYN) can contribute to CD8+ T cell dysfunction. Dynamic alterations of these metabolites between tumor cells and immune cells can similarly initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response. This review summarizes the new landscape beyond the classical metabolic pathways in tumor cells, highlighting the pivotal role of metabolic disturbance in the immunosuppressive microenvironment, especially how nutrient deprivation in TME leads to metabolic reprogramming of CD8+ T cells. Likewise, it emphasizes the current therapeutic targets or strategies related to tumor metabolism and immune response, providing therapeutic benefits for tumor immunotherapy and drug development in the future. Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Dynamic alterations of metabolites between tumor cells and immune cells initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response.

LARP4B promotes hepatocellular carcinoma progression and impairs sorafenib efficacy by activating SPINK1-mediated EGFR pathway.

La-related proteins (LARPs) regulate gene expression by binding to RNAs and exhibit critical effects on disease progression, including tumors. However, the role of LARP4B and its underlying mechanisms in the progression of hepatocellular carcinoma (HCC) remain largely unclear. In this study, we found that LARP4B expression is upregulated and correlates with poor prognosis in patients with HCC. Gain- and loss-of-function assays showed that LARP4B promotes stemness, proliferation, metastasis, and angiogenesis in vitro and in vivo. Furthermore, LARP4B inhibition enhances the antitumor effects of sorafenib and blocks the metastasis-enhancing effects of low sorafenib concentrations in HCC. Mechanistically, LARP4B expression is upregulated by METTL3-mediated N6-methyladenosine (m6A)-IGF2BP3-dependent modification in HCC. RNA- and RNA immunoprecipitation (RIP)- sequencing uncovered that LARP4B upregulates SPINK1 by binding to SPINK1 mRNA via the La motif and maintaining mRNA stability. LARP4B activates the SPINK1-mediated EGFR signaling pathway, which supports stemness, progression and sorafenib resistance in HCC. Additionally, a positive feedback loop with the LARP4B/SPINK1/p-AKT/C/EBP-ß axis is responsible for the sorafenib-therapeutic benefit of LARP4B depletion. Overall, this study demonstrated that LARP4B facilitates HCC progression, and LARP4B inhibition provides benefits to sorafenib treatment in HCC, suggesting that LARP4B might be a potential therapeutic target for HCC.

Meroterpenoids from Marine Sponge Hyrtios sp. and Their Anticancer Activity against Human Colorectal Cancer Cells.

Two new meroterpenoids, hyrtamide A (1) and hyrfarnediol A (2), along with two known ones, 3-farnesyl-4-hydroxybenzoic acid methyl ester (3) and dictyoceratin C (4), were isolated from a South China Sea sponge Hyrtios sp. Their structures were elucidated by NMR and MS data. Compounds 2-4 exhibited weak cytotoxicity against human colorectal cancer cells (HCT-116), showing IC50 values of 41.6, 45.0, and 37.3 µM, respectively. Furthermore, compounds 3 and 4 significantly suppressed the invasion of HCT-116 cells while also downregulating the expression of vascular endothelial growth factor receptor 1 (VEGFR-1) and vimentin proteins, which are key markers associated with angiogenesis and epithelial-mesenchymal transition (EMT). Our findings suggest that compounds 3 and 4 may exert their anti-invasive effects on tumor cells by inhibiting the expression of VEGFR-1 and impeding the process of EMT.

The Effect of Notch and Molecular Weight on the Impact Fracture Behavior of Polycarbonate.

The impact protection applications of polycarbonate (PC) products are gradually increasing. Due to the high sensitivity of PC to notches, research on notch impacts has become very important. In this paper, the impact performance of PC with two different molecular weights under different notch states was investigated. Three notch size factors, namely notch tip radius, notch angle, and notch center depth, were selected to design orthogonal experiments and research impact toughness. Subsequently, a single-factor study was conducted on the impact radius at the tip of the notch, which was the most important factor affecting the impact performance. Research shows that the brittle-ductile-transition tip radius of high-molecular-weight PC is 0.15 mm, and it has a higher impact toughness than low-molecular-weight PC during the brittle fracture process. The brittle-ductile-transition tip radius of lower molecular weight is 0.25 mm, while low-molecular-weight PC has a higher impact toughness during the ductile fracture process. The brittle and ductile fracture mechanisms of PC with different molecular weights were analyzed by observing the stress changes and cross-sectional morphology.

Deciphering the causal association and co-disease mechanisms between psoriasis and breast cancer.

Background: Prior research has indicated a link between psoriasis and the susceptibility to breast cancer (BC); however, a definitive causal relationship remains elusive. This study sought to elucidate the causal connection and shared underlying mechanisms between psoriasis and BC through bidirectional Mendelian randomization (MR) and bioinformatic approaches. Methods: We employed a bidirectional MR approach to examine the potential causal connection between psoriasis and BC. Genetic data pertaining to psoriasis and BC were sourced from extensive published genome-wide association studies. The inverse -variance weighted or wald ratio served as the primary method for estimating causal effects. Sensitivity analysis of the MR results was applied with multiple methods. Leveraged datasets from the Gene Expression Omnibus and the Cancer Genome Atlas repositories to identify common differentially expressed genes, shedding light on the shared mechanisms underlying these two conditions. Results: The MR analysis revealed that when considering psoriasis as an exposure factor, the incidences of BC (OR=1.027) and estrogen receptor negative (ER-) BC (OR=1.054) were higher than in the general population. When using Her2+ BC as an exposure factor, the risk of psoriasis was 0.822 times higher (OR=0.822) than in the general population. Sensitivity analysis indicated that the results were robust. Transcriptome analysis showed that CXCL13 and CCL20 were activated in both BC and psoriasis. Both diseases were also linked to neutrophil chemotaxis, the IL-17 pathway, and the chemokine pathway. Conclusion: The results suggest that psoriasis may increase the risk of BC, especially ER- BC, while reverse MR suggests a decreased risk of psoriasis in Her2+ BC. Transcriptome analysis revealed a shared mechanism between psoriasis and BC.

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action.

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

Trajectory of COVID-19 response and management strategy in China: scientific rationale driven strategy adjustments.

The pneumonia caused by novel coronavirus SARS-CoV-2 infection in early December 2019, which was later named coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO), rapidly spread across the world. China has made extraordinary efforts to this unprecedented pandemic, put its response and control at a very high level of infectious disease management (Category B but with measures for Category A), given top priority to the people and their lives, and balanced the pandemic control and socio-economic development. After more than three years' fighting against this disease, China downgraded the management of COVID-19 to Category B infectious disease on January 8, 2023 and the WHO declared the end of public health emergency on May 5, 2023. However, the ending of pandemic does not mean that the disease is no longer a health threat. Experiences against COVID-19 from China and the whole world should be learned to prepare well for the future public health emergencies. This article gives a systematic review of the trajectory of COVID-19 development in China, summarizes the critical policy arrangements and provides evidence for the adjustment during policy making process, so as to share experiences with international community and contribute to the global health for all humanity.

Electro-Induced Phase Transformation of a Conductive Metal-Organic Framework Film for Nonlinear Optical Switching.

Achieving metal-organic frameworks (MOFs) with nonlinear optical (NLO) switching is profoundly important. Herein, the conductive MOFs Cu-TCNQ phase I (Ph-I) and phase II (Ph-II) films were prepared using the liquid-phase-epitaxial layer-by-layer spin-coating method and steam heating method, respectively. Electronic experiments showed that the Ph-II film could be changed into the Ph-I film under an applied electric field. The third-order NLO results revealed that the Ph-I film had a third-order nonlinear reverse saturation absorption (RSA) response and the Ph-II film displayed a third-order nonlinear saturation absorption (SA) response. With increases in the heating time and applied voltage, the third-order NLO response realized the reversible transition between SA and RSA. The theoretical calculations indicated that Ph-I possessed more interlayer charge transfer, resulting in a third-order nonlinear RSA response that was stronger than that of Ph-II. This work applies phase-transformed MOFs to third-order NLO switching and provides new insights into the nonlinear photoelectric applications of MOFs.