An overview of the regulatory role of annexin A1 in the tumor microenvironment and its prospective clinical application (Review).

Although annexin A1 (ANXA1), a 37 kDa phospholipid­binding anti­inflammatory protein expressed in various tissues and cell types, has been investigated extensively for its regulatory role in cancer biology, studies have mainly focused on its intracellular role. However, cancer cells and stromal cells expressing ANXA1 have the ability to transmit signals within the tumor microenvironment (TME) through autocrine, juxtacrine, or paracrine signaling. This bidirectional crosstalk between cancer cells and their environment is also crucial for cancer progression, contributing to uncontrolled tumor proliferation, invasion, metastasis and resistance to therapy. The present review explored the important role of ANXA1 in regulating the cell­specific crosstalk between various compartments of the TME and analyzed the guiding significance of the crosstalk effects in promotion or suppressing cancer progression in the development of cancer treatments. The literature shows that ANXA1 is critical for the regulation of the TME, indicating that ANXA1 signaling between cancer cells and the TME is a potential therapeutic target for the development of novel therapeutic approaches for impeding cancer development.

Risk of primary Sjogren's Syndrome following human papillomavirus infections: a nationwide population-based cohort study.

Introduction: Viral infection is an exogeneous factor for primary Sjogren's syndrome (pSS). This study investigated the association between human papillomavirus (HPV) infections and pSS through a nationwide population based cohort study. Methods: Patients with HPV infections between January, 1999 and December, 2013 were included. The incidence of new-onset pSS in patients with HPV infections and non-HPV controls were derived. The multiple Cox regression model derived the risk of pSS in patients with HPV infections. Subgroup analysis and sensitivity analysis were performed to validate the association. Results: During a follow-up period of 12 years, the adjusted hazard ratio (aHR) of pSS in patients with HPV infections was significantly higher than that in non-HPV controls (aHR=1.64, 95% CI=1.47-1.83, P<0.001). The risk of pSS increased with age and the risk increased by 2.64-fold (95% CI= 2.37-2.93) for those older than 45 years. The significant association between HPV infections and the risk of pSS persisted in the sensitivity analysis restricted in HPV infections that lasted over 12 months (aHR=1.63, 95%CI=1.45-1.83, P<0.0001). Subgroup analyses revealed that both male (aHR=1.83, 95%CI=1.47-2.28, P<0.0001) and female (aHR=1.58, 95%CI=1.40-1.79, P<0.0001) patients with HPV infections and HPV-infected patients aged between 16 and 45 years (aHR=1.60, 95%CI=1.34-1.91, P<0.0001) and over 45 years (aHR=1.67, 95%CI=1.46-1.91, P<0.0001) were associated with a significantly greater risk of pSS. Conclusion: Patients with HPV infections presented with a significantly higher risk of pSS, regardless of age and sex.

Activation of TMEM16A Ca2+-activated Cl- channels by ROCK1/moesin promotes breast cancer metastasis.

Introduction: Transmembrane protein 16A (TMEM16A) is a Ca2+-activated chloride channel that plays a role in cancer cell proliferation, migration, invasion, and metastasis. However, whether TMEM16A contributes to breast cancer metastasis remains unknown. Objective: In this study, we investigated whether TMEM16A channel activation by ROCK1/moesin promotes breast cancer metastasis. Methods: Wound healing assays and transwell migration and invasion assays were performed to study the migration and invasion of MCF-7 and T47D breast cancer cells. Western blotting was performed to evaluate the protein expression, and whole-cell patch clamp recordings were used to record TMEM16A Cl- currents. A mouse model of breast cancer lung metastasis was generated by injecting MCF-7 cells via the tail vein. Metastatic nodules in the lung were assessed by hematoxylin and eosin staining. Lymph node metastasis, overall survival, and metastasis-free survival of breast cancer patients were assessed using immunohistochemistry and The Cancer Genome Atlas dataset. Results: TMEM16A activation promoted breast cancer cell migration and invasion in vitro as well as breast cancer metastasis in mice. Patients with breast cancer who had higher TMEM16A levels showed greater lymph node metastasis and shorter survival. Mechanistically, TMEM16A promoted migration and invasion by activating EGFR/STAT3/ROCK1 signaling, and the role of the TMEM16A channel activity was important in this respect. ROCK1 activation by RhoA enhanced the TMEM16A channel activity via the phosphorylation of moesin at T558. The cooperative action of TMEM16A and ROCK1 was supported through clinical findings indicating that breast cancer patients with high levels of TMEM16A/ROCK1 expression showed greater lymph node metastasis and poor survival. Conclusion: Our findings revealed a novel mechanism underlying TMEM16A-mediated breast cancer metastasis, in which ROCK1 increased TMEM16A channel activity via moesin phosphorylation and the increase in TMEM16A channel activities promoted cell migration and invasion. TMEM16A inhibition may be a novel strategy for treating breast cancer metastasis.

High Proton Conductivity in Nafion/Ni-MOF Composite Membranes Promoted by Ligand Exchange under Ambient Conditions.

Metal-organic frameworks (MOFs) have appeared to be promising competitive candidates as crystalline porous materials for proton conduction. Explorations of the method of preparation of proton conductive MOFs and the proton transfer mechanism have enabled them to attract widespread attention, and tremendous efforts have been made to improve the proton conductivity of MOFs. On the basis of our previous work, we explicitly propose that ligand exchange can upgrade the proton conduction performance of MOFs. Using MOF-azo as the precursor, the proton conductivities of exchange products MOF-bpy and MOF-bpe increase by 3.5- and 2.8-fold, respectively. After the MOFs had been doped into the Nafion matrix to prepare composite membranes, the proton conduction performance of composite membranes filled with subproducts (2.6 × 10-2 and 1.95 × 10-2 S cm-1) is significantly better than that of a composite membrane filled with a parent product (1.12 × 10-2 S cm-1) under ambient conditions (without heating or humidifying). The ligand exchange strategy presented herein demonstrates great promise for the development of high-proton conductivity MOFs and MOF composites with expanded future applications.

Honokiol inhibits proliferation of colorectal cancer cells by targeting anoctamin 1/TMEM16A Ca2+ -activated Cl- channels.

BACKGROUND AND PURPOSE: Ca2+ -activated Cl- channels (Ano1 channels) contribute to the pathogenesis of colorectal cancer. Honokiol is known to inhibit cell proliferation and tumour growth in colorectal cancer. However, the molecular target of honokiol remains unclear. This study aimed to investigate whether honokiol inhibited cell proliferation of colorectal cancer by targeting Ano1 channels. EXPERIMENTAL APPROACH: Patch-clamp techniques were performed to study the effect of honokiol on Ca2+ -activated Cl- currents in HEK293 cells overexpressing Ano1- or Ano2-containing plasmids or in human colorectal carcinoma SW620 cells. Site-directed mutagenesis was used to identify the critical residues for honokiol-induced Ano1 inhibition. Proliferation of SW620 cells or human intestinal epithelial NCM460 cells by CCK-8 assays. KEY RESULTS: Honokiol blocked Ano1 currents in Ano1-overexpressing HEK293 cells and SW620 cells. Honokiol more potently inhibited Ano1 currents than Ano2 currents. Three amino acids (R429, K430 and N435) were critical for honokiol-induced Ano1 inhibition. The R429A/K430L/N435G mutation reduced the sensitivity of Ano1 to honokiol. Honokiol inhibited SW620 cell proliferation, and this effect was reduced by Ano1-shRNAs. Furthermore, Ano1 overexpression promoted proliferation in NCM460 cells with low Ano1 endogenous expression and resulted in an increased sensitivity to honokiol. Overexpression of the R429A/K430L/N435G mutation reduced WT Ano1-induced increase in the sensitivity of NCM460 cells to honokiol. CONCLUSION AND IMPLICATIONS: We identified a new anticancer mechanism of honokiol, through the inhibition of cell proliferation, by targeting Ano1 Ca2+ -activated Cl- channels.

Coordination-Induced N-H Bond Splitting of Ammonia and Primary Amine of CuI -MOFs.

We report a porous three-dimensional anionic tetrazolium based CuI -MOF 1, which is capable of cleaving the N-H bond of ammonia and primary amine, as well as the O-H bond of H2 O along with spontaneous H2 evolution. In the gas-solid phase reaction of 1 with ammonia and water vapor, CuI -MOF 1 was gradually oxidized to NH2 -CuII -MOF and OH-CuII -MOF, through single-crystal-to-single-crystal (SCSC) structural transformations, which was confirmed by XPS, PXRD and X-ray single-crystal diffraction. Density functional theory (DFT) demonstrated that CuI -MOF could lower N-H bond dissociation free energy of ammonia through coordination-induced bond weakening and promote H2 evolution by the reduction potential of 1. To our knowledge, this is the first example of MOFs that activate ammonia and amine in gas-solid manner.

Ca2+-activated Cl- channel TMEM16A inhibition by cholesterol promotes angiogenesis in endothelial cells.

Introduction: Ca2+-activated Cl- channel TMEM16A is expressed in endothelial cells, and contributes to many diseases such as hypertension, blood-brain barrier dysfunction, and pulmonary hypertension. It remains unclear whether TMEM16A regulates endothelial angiogenesis, which participates in many physiological and pathological processes. Cholesterol regulates many ion channels including TMEM16A, and high cholesterol levels contribute to endothelial dysfunction. It remains to be determined whether cholesterol regulates TMEM16A expression and function in endothelial cells. Objective: This study aimed to investigate whether cholesterol regulated TMEM16A expression and function in endothelial angiogenesis. Methods: Whole-cell patch clamp techniques were used to record Ca2+-activated Cl- currents in human aortic endothelial cells (HAECs) and HEK293 cells transfected with TMEM16A-overexpressing plasmids. Western blot was used to examine the expression of TMEM16A and DNA methyltransferase 1 (DNMT1) in HAECs. CCK-8 assay, would healing assay, and tube formation assay were used to test endothelial cell proliferation, migration and angiogenesis, respectively. Results: TMEM16A mediates the Ca2+-activated Cl- channel in HAECs. Cholesterol treatment inhibited TMEM16A expression via upregulation of DNMT1 in HAECs, and the inhibitory effect of cholesterol on TMEM16A expression was blocked by 5-aza, the DNMT1 inhibitor. In addition, direct application of cholesterol inhibited TMEM16A currents in heterologous HEK293 cells with an IC50 of 0.1209 µM. Similarly, cholesterol directly inhibited TMEM16A currents in HAECs. Furthermore, TMEM16A knockdown increased in vitro tube formation, cell migration and proliferation of HAECs, and TMEM16A overexpression produced the opposite effect. Conclusion: This study reveals a novel mechanism of cholesterol-mediated TMEM16A inhibition, by which cholesterol reduces TMEM16A expression via DNMT1-mediated methylation and directly inhibits channel activities. TMEM16A channel inhibition promotes endothelial cell angiogenesis.

Simvastatin inhibits oral squamous cell carcinoma by targeting TMEM16A Ca2+-activated chloride channel.

PURPOSE: Ca2+-activated chloride channel TMEM16A has been found to be overexpressed in many cancers including head and neck squamous cell carcinoma (HNSCC). Nevertheless, the role of TMEM16A in oral squamous cell carcinoma (OSCC) remains unclear. Although simvastatin is known to produce anti-tumor effect, the mechanisms by which simvastatin inhibits cancer remain unclear. METHODS: In this study, we explored the role of TMEM16A expression in human OSCC tissues using both TCGA dataset and immunohistochemistry. CCK-8 assay was applied to evaluate cell proliferation. Patch clamp technique was applied to record TMEM16A Cl- currents. RESULTS: We found that high TMEM16A expression is related with large tumor size, lymph node metastasis, and poor clinical outcome in patients with OSCC. In addition, TMEM16A overexpression could promote cell proliferation, and inhibition of TMEM16A channel activities could suppress cell proliferation in OSCC cells. Furthermore, simvastatin could suppress TMEM16A channel activities, and inhibited cell proliferation in OSCC cells via TMEM16A. CONCLUSION: Our findings identify a novel anti-tumor mechanism of simvastatin by targeting TMEM16A. Simvastatin may represent an innovative strategy for treating OSCC with high TMEM16A expression.

Construction of porous 2D MOF nanosheets for rapid and selective adsorption of cationic dyes.

Porous two-dimensional metal-organic framework (2D-MOF) nanosheets Zr-BTB-H4TBAPy and PCN-134-2D were synthesized and characterized by X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and zeta potential and subjected to dye adsorption and separation investigation. These 2D-MOF nanosheets are ultrathin, have large surface area and high water stability and can selectively adsorb cationic dyes, rhodamine B (RhB) and methylene blue (MLB), from aqueous solutions, with removal rates of nearly 100% within 10 min. The adsorption kinetic results showed that Zr-BTB-H4TBAPy and PCN-134-2D could effectively and selectively remove cationic dyes from water, followed a pseudo-second-order kinetic model and fitted well with the Freundlich isotherm. The adsorption mechanism studies further indicated that their excellent adsorption and separation performance could be ascribed to their ultrathin and porous features, plentiful exposed surface-active sites, and favorable electrostatic interactions between the adsorbents and cationic dyes. Moreover, the porous 2D MOF nanosheets displayed excellent recyclability and reusability. These outstanding features make them potentially applicable for rapid and selective cationic dye adsorption and separation.

BiOI Particles Confined into Metal-Organic Framework NU-1000 for Valid Photocatalytic Hydrogen Evolution under Visible-Light Irradiation.

Herein, a surface site engineering strategy is used to construct a porous Z-scheme heterojunction photocatalyst for photocatalytic hydrogen evolution (PHE) by integration of BiOI in a mesoporous Zr-based metal-organic framework (MOF) NU-1000. Three high-quality and highly dispersed BiOI@NU-1000 heterojunction materials are synthesized, and a set of methods is used to characterize these materials, indicating that the BiOI@NU-1000 heterojunction can retain high porosity and crystallinity of the parent NU-1000. Furthermore, the built-in electric field of the BiOI@NU-1000 composite can effectively tune the band gap, promote the separation of photoinduced charge carriers, improve photocurrent intensity, and reduce photoelectric impedance. Under visible-light irradiation, BiOI@NU-1000-2 showed the best photocatalytic performance in the field of MOF-based photocatalysts for PHE, with a hydrogen production rate of up to 610 µmol h-1 g-1. This study will open up opportunities for the construction of Z-scheme photocatalysts based on the highly porous MOF materials to inspire the development of innovative photocatalysts.

Efficient and Selective Visible-Light-Driven Oxidative Coupling of Amines to Imines in Air over CdS@Zr-MOFs.

Construction of porous photoactive MOF-based composite systems is regarded as one of the most effective strategies to improve light harvesting, increase the surface area, provide plenty of exposed active sites, and promote the reduction and oxidation abilities of some organic photocatalytic reactions. Herein, we synthesized porous CdS@Zr-MOF photocatalysts based on the representative photocatalyst CdS and crystalline Zr-MOFs, such as MOF-808, NU-1000, and PCN-222, to illustrate their excellent photocatalytic performance for the synthesis of imines in air. The morphology and composition of these photocatalysts were investigated by X-ray powder diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), indicating their crystallinity, high porosity, and interfacial interaction between constituents. Compared with individual components, these porous CdS@Zr-MOF composites could remarkably promote photocatalytic activity for the oxidative coupling of amines under air and visible-light conditions. The photocatalytic reaction showed broad substrate suitability. More importantly, the conversion yield reached up to 95% for the inactive aliphatic amines, and imines were formed as the single product. The improvement of the photocatalytic performance of CdS@Zr-MOF composites can be mainly ascribed to their high surface areas, more exposed active sites, excellent dispersion of CdS, and special porous photocatalytic systems, which tune the band gap, broaden the light response range, and facilitate the carrier separation.

Obtaining Information about Operation of Centrifugal Compressor from Pressure by Combining EEMD and IMFE.

Based on entropy characteristics, some complex nonlinear dynamics of the dynamic pressure at the outlet of a centrifugal compressor are analyzed, as the centrifugal compressor operates in a stable and unstable state. First, the 800-kW centrifugal compressor is tested to gather the time sequence of dynamic pressure at the outlet by controlling the opening of the anti-surge valve at the outlet, and both the stable and unstable states are tested. Then, multi-scale fuzzy entropy and an improved method are introduced to analyze the gathered time sequence of dynamic pressure. Furthermore, the decomposed signals of dynamic pressure are obtained using ensemble empirical mode decomposition (EEMD), and are decomposed into six intrinsic mode functions and one residual signal, and the intrinsic mode functions with large correlation coefficients in the frequency domain are used to calculate the improved multi-scale fuzzy entropy (IMFE). Finally, the statistical reliability of the method is studied by modifying the original data. After analysis of the relationships between the dynamic pressure and entropy characteristics, some important intrinsic dynamics are captured. The entropy becomes the largest in the stable state, but decreases rapidly with the deepening of the unstable state, and it becomes the smallest in the surge. Compared with multi-scale fuzzy entropy, the curve of the improved method is smoother and could show the change of entropy exactly under different scale factors. For the decomposed signals, the unstable state is captured clearly for higher order intrinsic mode functions and residual signals, while the unstable state is not apparent for lower order intrinsic mode functions. In conclusion, it can be observed that the proposed method can be used to accurately identify the unstable states of a centrifugal compressor in real-time fault diagnosis.

Photochromism of metal-organic frameworks based on carbazole-dicarboxylic acid and bipyridine: sensing adjustment by controlling strut-to-strut energy transfer.

In this paper, two energy-transfer photochromic metal-organic frameworks (MOFs) {[Zn(L)0.5(bpy)]·H2O·DMF}n (1) and {[Zn(L)0.5(bpe)]·2H2O·DMF}n (2) (H4L = 9,9'-(1,4-phenylenebis(methylene))bis(9H-carbazole-3,6-dicarboxylic acid), bpy = 4,4'-bipyridine, bpe = 4,4'-vinylenedipyridine) were designed and synthesized. Both 1 and 2 showed similar pillared-paddle wheel type frameworks with bpy and bpe as the chromophore, respectively, and L4- as the antenna-type light harvester, yielding strut-to-strut energy transfer (antenna behavior) within the well-ordered structures. Among them, 1 displayed excellent energy-transfer photochromic behavior under UV light accompanied by color transformation from colorless to purple. In addition, the photochromic behavior of 1 has obvious, fast, controllable and reversible characteristics. On the other hand, 2 showed a different energy-transfer photochromic behavior in the aspects of color changing, gamut, and sensitivity. The variation has been ascribed to the substitution of chromophore bpy in 1 with bpe in 2, which influences the efficiency of energy transfer within the MOFs. Therefore, with the structural diversity and tunability of MOFs, the sensitivity, color, and gamut of energy-transfer of the photochromic MOFs can be tuned by the appropriate choice of the constitutions of MOFs. This work will provide useful guidance for developing novel energy-transfer photochromic MOF materials.

Surfactant-assisted assembly of nanoscale zinc coordination compounds to enhance tandem conversion reactions in water.

Precise control over the morphology and size of coordination polymers (CPs) is crucial for extending these inorganic-organic materials to many advanced applications, in particular for heterogeneous catalysis. In this work, two Zn-based CPs, {[Zn3(idbt)2(4,4'-dmbpy)2]·H2O}n (1) and {[Zn3(idbt)2(H2O)3]·H2O}n (2) (H3idbt = 5,5'-(1H-imidazole-4,5-diyl)-bis-(2H-tetrazole), 4,4'-dmbpy = 4,4''-dimethyl-2,2'-bipyridine), were synthesized through solvothermal reactions. The morphologies and particle sizes of 1 and 2 could be controlled from large scale to nanoscale by regulating the amount of poly(vinyl alcohol) (PVA). Furthermore, for the conversion reactions of nitromethylbenzenes into benzoic acids, the catalytic properties of nanoscale 1 and 2 were much more efficient than those of large size of 1 and 2, because of the benefit of readily accessible active sites in the nanoscale sized particles, which provide a tunable and functionalizable platform for the conversion reaction by minimizing the diffusion distance but do little for the selectivity.

A Highly Sensitive and Recyclable Ln-MOF Luminescent Sensor for the Efficient Detection of Fe3+ and CrVI Anions.

Two new three-dimensional (3D) LnIII metal-organic frameworks (MOFs) were designed and successfully obtained via a solvothermal reaction between lanthanide(III) nitrates and a semi-flexible carbazole tetracarboxylate acid linker as a high-performance chromophore. 1 and 2 possess porous 3D networks with channels along the a axis, and more importantly, they show a highly sensitive and selective fluorescence quenching response to Fe3+ and CrVI anions. The sensing mechanism investigation revealed that the weak interactions of Fe3+ with nitrogen atoms of carbazole and deprotonated carboxylic acids protruding into the pores of MOFs quenched the luminescence of 1 and 2 effectively. In addition, the competition absorption also played an important role in the luminescence quenching detection of Fe3+ based on 1, and CrVI anions based on 1 and 2. Therefore, 1 and 2 represent an alternative example of regenerable luminescence based sensors for the quantitative detection of Fe3+ and CrVI anions.

Gene co-expression network analysis identifies trait-related modules in Arabidopsis thaliana.

MAIN CONCLUSION: A comprehensive network of the Arabidopsis transcriptome was analyzed and may serve as a valuable resource for candidate gene function investigations. A web tool to explore module information was also provided. Arabidopsis thaliana is a widely studied model plant whose transcriptome has been substantially profiled in various tissues, development stages and other conditions. These data can be reused for research on gene function through a systematic analysis of gene co-expression relationships. We collected microarray data from National Center for Biotechnology Information Gene Expression Omnibus, identified modules of co-expressed genes and annotated module functions. These modules were associated with experiments/traits, which provided potential signature modules for phenotypes. Novel heat shock proteins were implicated according to guilt by association. A higher-order module networks analysis suggested that the Arabidopsis network can be further organized into 15 meta-modules and that a chloroplast meta-module has a distinct gene expression pattern from the other 14 meta-modules. A comparison with the rice transcriptome revealed preserved modules and KEGG pathways. All the module gene information was available from an online tool at http://bioinformatics.fafu.edu.cn/arabi/ . Our findings provide a new source for future gene discovery in Arabidopsis.

Descriptions of Entropy with Fractal Dynamics and Their Applications to the Flow Pressure of Centrifugal Compressor.

In this study, some important intrinsic dynamics have been captured after analyzing the relationships between the dynamic pressure at an outlet of centrifugal compressor and fractal characteristics, which is one of powerful descriptions in entropy to measure the disorder or complexity in the nonlinear dynamic system. In particular, the fractal dynamics of dynamic pressure of the flow is studied, as the centrifugal compressor is in surge state, resulting in the dynamic pressure of flow and becoming a serious disorder and complex. First, the dynamic pressure at outlet of a centrifugal compressor with 800 kW is tested and then obtained by controlling the opening of the anti-surge valve at the outlet, and both the stable state and surge are initially tested and analyzed. Subsequently, the fractal dynamics is introduced to study the intrinsic dynamics of dynamic pressure under various working conditions, in order to identify surge, which is one typical flow instability in centrifugal compressor. Following fractal dynamics, the Hurst exponent, autocorrelation functions, and variance in measure theories of entropy are studied to obtain the mono-fractal characteristics of the centrifugal compressor. Further, the multi-fractal spectrums are investigated in some detail, and their physical meanings are consequently explained. At last, the statistical reliability of multi-fractal spectrum by modifying the original data has been studied. The results show that a distinct relationship between the dynamic pressure and fractal characteristics exists, including mono-fractal and multi-fractal, and such fractal dynamics are intrinsic. As the centrifugal compressor is working under normal condition, its autocorrelation function curve demonstrates apparent stochastic characteristics, and its Hurst exponent and variance are lower. However, its autocorrelation function curve demonstrates an apparent heavy tail distribution, and its Hurst exponent and variance are higher, as it is working in an unstable condition, namely, surge. In addition, the results show that the multi-fractal spectrum parameters are closely related to the dynamic pressure. With the state of centrifugal compressor being changed from stable to unstable states, some multi-fractal spectrum parameters Δα, Δf(α), αmax, and f(αmin) become larger, but αmin in the multi-fractal spectrum show the opposite trend, and consistent properties are graphically shown for the randomly shuffled data. As a conclusion, the proposed method, as one measure method for entropy, can be used to feasibly identify the incipient surge of a centrifugal compressor and design its surge controller.

Cu(i) coordination polymers (CPs) as tandem catalysts for three-component sequential click/alkynylation cycloaddition reaction with regiocontrol.

To expand coordination polymers (CPs) as solid catalysts to selectively catalyze the three-component tandem click/alkynylation reaction for their fully substituted triazole skeletons, two Cu(i)-based CPs (CuI-CPs), [CuBr(aas-TPB)]n (1) and [Cu3I3(aas-TPB)2]n (2) (TPB = N,N,N-tri(3-pyridinyl)-1,3,5-benzenetricarboxamine), have been prepared. Because of the template effect of anions (Br- and I-), the structure of compounds is regulated under solvothermal conditions. CP 1 exhibited a one-dimensional (1D) chain, while the double strand framework with the Cu3I3 cluster platform was observed in 2. Furthermore, the different product selectivities of catalyzing terminal alkynes, benzyl azide and bromoalkyne to synthesize triazole skeletons have been caused by the significantly structural diversity of 1 and 2. The distinct structural feature of 2 endows it with unique multinuclear platforms (Cu3I3) and reaction pathways to promote the three-component tandem click/alkynylation cycloaddition reaction. As a result, 2 can be an outstanding catalyst candidate for sequential click/alkynylation cycloaddition, while 1 can efficiently catalyze the generation of click products.

Near-Net Forming Complex Shaped Zr-Based Bulk Metallic Glasses by High Pressure Die Casting.

Forming complex geometries using the casting process is a big challenge for bulk metallic glasses (BMGs), because of a lack of time of the window for shaping under the required high cooling rate. In this work, we open an approach named the "entire process vacuum high pressure die casting" (EPV-HPDC), which delivers the ability to fill die with molten metal in milliseconds, and create solidification under high pressure. Based on this process, various Zr-based BMGs were prepared by using industrial grade raw material. The results indicate that the EPV-HPDC process is feasible to produce a glassy structure for most Zr-based BMGs, with a size of 3 mm × 10 mm and with a high strength. In addition, it has been found that EPV-HPDC process allows complex industrial BMG parts, some of which are hard to be formed by any other metal processes, to be net shaped precisely. The BMG components prepared by the EVP-HPDC process possess the advantages of dimensional accuracy, efficiency, and cost compared with the ones formed by other methods. The EVP-HPDC process paves the way for the large-scale application of BMGs.