Phase Transition Control in Molecular Solids via Complementarity of Hydrogen-Bond Strength.

Phase transitions in molecular solids involve synergistic changes in chemical and electronic structures, leading to diversification in physical and chemical properties. Despite the pivotal role of hydrogen bonds (H-bonds) in many phase-transition materials, it is rare and challenging to chemically regulate the dynamics and to elucidate the structure-property relationship. Here, four high-spin CoII compounds were isolated and systematically investigated by modifying the ligand terminal groups (X=S, Se) and substituents (Y=Cl, Br). S-Cl and Se-Br undergo a reversible structural phase transition near room temperature, triggering the rotation of 15-crown-5 guests and the swing between syn- and anti-conformation of NCX- ligands, accompanied by switchable magnetism. Conversely, S-Br and Se-Cl retain stability in ordered and disordered phases, respectively. H-bonds geometric analysis and ab initio calculations reveal that the electronegativity of X and Y affects the strength of NY-ap-H⋅⋅⋅X interactions. Entropy-driven structural phase transitions occur when the H-bond strength is appropriate; otherwise, the phase stays unchanged if it is too strong or weak. This work highlights a phase transition driven by H-bond strength complementarity - pairing strong acceptor with weak donor and vice versa, which offers a straightforward and effective approach for designing phase-transition molecular solids from a chemical perspective.

2D Porphyrin-Based Covalent-Organic Framework/PEG Composites: A Rational Strategy for Photocatalytic Hydrogen Evolution.

Two-dimensional porphyrin-based covalent-organic frameworks (2D-por-COFs) have gained significant attention as attractive platforms for efficient solar light conversion into hydrogen production. Herein, it is found that introducing transition metal zinc and polyethylene glycol (PEG) into 2D-por-COFs can effectively improve the photocatalytic hydrogen evolution performance. The photocatalytic hydrogen evolution rate of ZnPor-COF is 2.82 times higher than that of H2Por-COF. Moreover, ZnPor-COF@PEG has the highest photocatalytic hydrogen evolution efficiency, which is 1.31 and 3.7 times that of pristine ZnPor-COF and H2Por-COF, respectively. The filling of PEG makes the layered structure of COFs more stable. PEG reduces the distortion and deformation of the carbon skeleton after the experiment of photocatalytic hydrogen evolution. The layered stacking and crystallization of 2D-por-COFs are also enhanced. Meanwhile, the presence of PEG also accelerates the transfer of excited electrons and enhances the photocatalytic hydrogen evolution activity. This strategy will provide valuable insights into the design of 2D-por-COFs as efficient solid photocatalysts for solar-driven hydrogen production.

Expression of PFKFB3 and Ki67 in lung adenocarcinomas and targeting PFKFB3 as a therapeutic strategy.

Phosphofructokinase-2/fructose-2, 6-bisphosphatase 3 (PFKFB3) catalyzes the synthesis of F2,6BP, which is an allosteric activator of 6-phosphofructo-1-kinase (PFK-1): the rate-limiting enzyme of glycolysis. During tumorigenesis, PFKFB3 increases glycolysis, angiogenesis, and tumor progression. In this study, our aim was to investigate the significance of PFKFB3 and Ki67 in human lung adenocarcinomas and to target PFKFB3 as a therapeutic strategy. In this study, we determined the expression levels of PFKFB3 mRNA and proteins in cancerous and normal lung adenocarcinomas by quantitative reverse transcription PCR (qRT-PCR), Western blot analysis, and tissue microarray immunohistochemistry analysis, respectively. In human adenocarcinoma tissues, PFKFB3 and Ki67 protein levels were related to the clinical characteristics and overall survival. Both PFKFB3 mRNA and protein were significantly higher in lung adenocarcinoma cells (all P < 0.05). A high expression of PFKFB3 and Ki67 were associated with the degree of differentiation, TNM staging, lymph node metastasis, and survival. A high expression of PFKFB3 protein was an independent prognostic marker in lung adenocarcinoma. Subsequently, 1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PFK15) was used as a selective antagonist of PFKFB3. Glycolytic flux was determined by measuring glucose uptake, F2,6BP, and lactate production. Cell viability, cell cycle, cell apoptosis, cell migration, and invasion were analyzed by MTT, flow cytometry, Western blot analysis, wound healing assay, and transwell chamber assay. By targeting PFKFB3, it inhibited cell viability and glycolytic activity. It also caused apoptosis and induced cell cycle arrest. Furthermore, the migration and invasion of A549 cells was inhibited. We conclude that PFKFB3 bears an oncogene-like regulatory element in lung adenocarcinoma progression. In the treatment of lung adenocarcinoma, targeting PFKFB3 would be a promising therapeutic strategy.

LAMP3 expression correlated with poor clinical outcome in human ovarian cancer.

Lysosome-associated membrane protein 3 belongs to the lysosome-associated membrane glycoprotein family, which is associated with lymph node, metastasis, poor overall survival, and resistance to chemotherapy and radiotherapy. Epithelial ovarian cancer is one of the most deadly global female gynecologic malignant tumors. Its clinical outcome is poor and most epithelial ovarian cancer patients tend to relapse because of drug resistance. However, lysosome-associated membrane protein 3 expression in epithelial ovarian cancer and its relationship between clinicopathologic factors remain poorly understood. To clarify the prognostic implications of lysosome-associated membrane protein 3 in epithelial ovarian cancer, we analyzed both messenger RNA and protein levels of lysosome-associated membrane protein 3 in ovarian carcinomas. Polymerase chain reaction results showed higher expression of lysosome-associated membrane protein 3 messenger RNA in epithelial ovarian cancer than in noncancerous tissues. Immunohistochemical results showed that high lysosome-associated membrane protein 3 cytoplasmic expression was significantly related to tumor grade ( p = 0.038), lymph node metastasis ( p = 0.049), metastasis ( p < 0.001), level of CA125 ( p = 0.030), and International Federation of Gynecology and Obstetrics (FIGO) ( p < 0.001). High lysosome-associated membrane protein 3 nuclear expression was significantly associated with tumor grade ( p = 0.046), tumor single or double (representative whether the tumor involving one or both ovaries) ( p = 0.016), metastasis ( p < 0.001), and FIGO stage ( p < 0.001). Survival analysis indicated that high lysosome-associated membrane protein 3 cytoplasmic expression (hazard ratio: 4.632, 95% confidence interval: 2.421-8.864; p < 0.001), patients' age (hazard ratio: 1.729, 95% confidence interval: 1.027-2.911; p = 0.039), and FIGO stage (hazard ratio: 2.049, 95% confidence interval: 1.113-3.774; p = 0.021) were significantly correlated with poor survival outcome of epithelial ovarian cancer patients.

Low expression of fibulin-1 correlates with unfavorable prognosis in gastric cancer.

The tumor-suppressing role of fibulin-1 has been described in several types of cancers. However, the expression and role of fibulin-1 in the development and progression of gastric cancer (GC) remain largely unknown. In this study, RT-PCR and immunochemistry were used to detect the fibulin-1 expression in GC samples. We have found that the fibulin-1 protein and mRNA levels were downregulated in GC. When investigating the correlation between fibulin-1 expression and clinicopathological characteristics, we have found that low fibulin-1 protein expression was associated with poor tumor differentiation and advanced N stage. Low fibulin-1 protein expression was also an independent prognostic factor for patient survival. To clarify the reason of fibulin-1 downregulation in GC, the mRNA expression and methylation status of fibulin-1 were examined in GC fresh tissue samples (n = 36). We found that the transcriptional expression of fibulin-1 was negatively associated with fibulin-1 promoter hypermethylation, and fibulin-1 hypermethylation was associated with Helicobacter pylori infection. Finally, the effects of fibulin-1 overexpression on cell proliferation and apoptosis were examined. We have found that fibulin-1 overexpression suppressed the growth of GC both in vitro and in vivo and induced apoptosis by increasing cleaved caspase-3 expression. In conclusion, fibulin-1 acts as a tumor suppressor gene, is frequently hypermethylated in GC, and can potentially serve as a useful biomarker for patient prognosis.

SO3-COF@Al2O3 modified cathode electrode materials enhance the cycling ability of lithium sulfur batteries.

Herein, a covalent organic framework (SO3-COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO3-COF@Al2O3. The experimental results show that SO3-COF@Al2O3 can effectively inhibit the shuttle effect of soluble lithium polysulfide (LiPSs) in LSBs after loading the active material sulfur, and exhibits better cycling behavior than the initial polymer SO3-COF. The initial discharge specific capacity of this electrode material at 0.05C is as high as 1141 mA h g-1, and the capacity can be maintained at 466 mA h g-1 after 500 cycles with a capacity decay rate of 0.08% per cycle.

Integrated carbon nanotube and triazine-based covalent organic framework composites for high capacitance performance.

As a rising class of crystallographic organic polymers, covalent-organic frameworks (COFs) have high specific surface areas, ordered pore structures, and designability, which exhibit broad application prospects in the energy storage sector. However, their low electrical conductivity hinders their potential use in supercapacitors. To improve the electrical conductivity, we introduced carboxylated multi-walled carbon nanotubes to obtain a series of carbon nanotube@COF composites by a facile one-pot method, in which 2D TFA-COFs are in situ grown on the surface of carboxylated multi-walled carbon nanotubes. Among them, the CNT@TFA-COF-3 composite exhibits good crystallinity, regular pores, excellent stability and a specific surface area of 1034 m2 g-1. As expected, as a capacitive electrode material, the CNT@TFA-COF composite shows improved electrochemical performance. Notably, the value of specific capacitance of the CNT@TFA-COF-3 composite (338 F g-1) is about 8.5, 4.9, and 7.5 times higher than those of TFA-COFs, CNTs, and the CNT/TFA-COF physically mixed complex at a current density of 1.0 A g-1, respectively. Furthermore, the CNT@TFA-COF-3 supercapacitor exhibits long-term cycle chemical stability and splendid rate capability even after 7000 charge-discharge cycles. The successful preparation of the CNT@TFA-COF-3 composite can provide new ideas for the construction of new COF-based composites and the development of new materials for energy storage.

Triazine covalent organic framework (COF)/θ-Al2O3 composites for supercapacitor application.

Currently, the preparation of high-performance electrode materials is urgently needed for supercapacitors. As a new kind of organic porous material, covalent organic frameworks (COFs) with an ordered pore structure, a high specific surface area and designability, have shown great potential application value as electrode materials for supercapacitors. However, their potential application in supercapacitors is limited by the poor conductivity of COFs. Here, we in situ grew the highly crystalline triazine-based covalent organic framework DHTA-COF on a modified θ-Al2O3 substrate to obtain the composites Al2O3@DHTA-COFs. Some of the obtained Al2O3@DHTA-COF composites can maintain some degree of crystallinity, good stability and a vesicular structure. Compared to the precursors θ-Al2O3 and DHTA-COF, the 50%Al2O3@DHTA-COF composite has superior electrochemical properties as electrode materials for supercapacitors. Under the same conditions, the specific capacitance values of 50%Al2O3@DHTA-COF (261.5 F g-1 at 0.5 A g-1) are 6.2 and 9.6 times higher than the values of DHTA-COF and θ-Al2O3-CHO, respectively. Additionally, the 50%Al2O3@DHTA-COF electrode material exhibited long-term cycling stability even after 6000 charge-discharge cycles. The study can provide some reference for the development of COF-based composite materials for energy storage.

[Vulvar intraepithelial neoplasia: a clinicopathologic study of twenty cases].

OBJECTIVE: To investigate the clinical, pathological and immunohistochemical features of vulvar intraepithelial neoplasia (VIN). METHODS: According to the 2004 modified terminology of International Society for the Study of Vulvovaginal Diseases (ISSVD), the cases were diagnosed as VIN from patients who had performed vulvar biopsy in Beijing Wuzhou Women's Hospital from February 2009 to December 2011, which were reclassified as usual VIN and differentiated VIN. The clinical and pathological studies were conducted respectively. MaxVision immunohistochemical staining was used to detect the expression of Ki-67, p16 and p53 proteins. RESULTS: There were 20 cases of VIN in 237 patients, and the incidence of VIN was 8.4% in all of contemporary vulvar biopsy. In 17 cases of usual VIN, mean age was 29.6 years, the lesion typically presented with atypical cells involving almost all layers of the epithelium, which was equivalent to the high-grade squamous intraepithelial neoplasia of cervix. Immunohistochemistry for Ki-67 and p16 was strongly positive in usual VIN. High risk human papillomavirus (HPV) detection was also positive. The incidence of differentiated VIN was less than usual VIN, and there were only 3 cases in this study. In differentiated VIN, patients aged over 50 years, with mean of 53.7 years, and the lesion most commonly presented with lichen sclerosis background. There were epithelial thickening and extending, and parakeratosis, and atypia was strictly confined to the basal and parabasal layers of the epithelium where the cells enlarged with abundant eosinophilic cytoplasm, presented with prominent nucleoli, increased cellularity and abnormal keratinization. In differentiated VIN, p53 was strongly positive, Ki-67 and p16 immunohistochemical expression was confined to the basal layer only. CONCLUSIONS: VIN is a precursor of invasive squamous cell carcinoma of the vulva. The modified terminology of ISSVD classifies VIN as high-grade lesions. Definitive pathological diagnosis of VIN plays an important role in its timely treatment and the prevention of vulvar carcinoma.

Conjugated Microporous Polymers Doped with Rare Earth Ions: Synthesis, Characterization and Energy Transfer.

In order to study the energy transfer between the conjugated polymer and rare-earth ions, a series of conjugated microporous polymers (CMPs) CMP-COOH@M (M=Eu3+ , Tb3+ , La3+ , and Sm3+ ) with different kinds of rare-earth ions was synthesized, in which the conjugated networks can effectively improve the luminescence of rare-earth ions due to the effective energy transfer from the CMP network to the rare-earth ions centers. The absolute quantum yield of CMP-COOH (ΦFL ) is 29.1 %, while the ΦFL value of CMP-COOH@Eu, CMP-COOH@Tb, CMP-COOH@La, and CMP-COOH@Sm is 9.4, 8.6, 14.3, and 9.1 %, respectively. This result indicates that the quantum efficiency of CMPs network is 1/2-1/3 of the original one due to the coordination of rare earth ions, that is, rare-earth ions can be recognized as fine modulators to adjust the emission color of CMPs in a controlled manner through controlling the species of rare-earth ions.

Second-order nonlinear optical properties of trisubstituted Keggin and Wells-Dawson polyoxometalates: density functional theory investigation of the inorganic donor-conjugated bridge-acceptor structure.

The donor-conjugated bridge-acceptor (D-A) model, as a simple molecular scheme, has been successfully used in the development of second-order organic compound, organometallic compound, and metal complex nonlinear optical (NLO) materials. However, for the totally inorganic molecules, the use of this model is still prohibitive. In the present paper, time-dependent density functional theory (TDDFT) was used to investigate the second-order NLO properties of vanadium- and molybdenum-trisubstituted Keggin and Wells-Dawson polyoxometalates (POMs). The results show that these POM clusters possess D-A structures. The oxygen atoms in the cap region and metal (vanadium and molybdenum) atoms in another cap region in these POM clusters can be viewed as the electron donor and acceptor, respectively. The vanadium ion derivatives possess larger second-order NLO responses and dipole moment than molybdenum ions derivatives; thus, the three vanadium atoms in the cap region act as a strong acceptor related to the three molybdenum atoms in cap region in our D-A scheme. The vanadomolybdate with Wells-Dawson structure displays the good second-order NLO response because of the relevant long conjugated bridge and strong acceptor. This D-A model may be an effective approach for optimizing the first hyperpolarizabilities of inorganic POM clusters.

Porous Cationic Covalent Triazine-Based Frameworks as Platforms for Efficient CO2 and Iodine Capture.

Porous cationic covalent triazine-based frameworks (CTFs) with imidazolium salts as tectons were prepared via ionothermal synthesis. The high-PF6 - -content CTF shows the CO2 adsorption of 44.7 cm3 g-1 and I2 capture capacity of 312 wt %. The influence of counterion species and contents on the porosities, CO2 adsorptions, and I2 capture capacities of the CTFs has been investigated.

Design of Novel Haptens and Development of Monoclonal Antibody-Based Immunoassays for the Simultaneous Detection of Tylosin and Tilmicosin in Milk and Water Samples.

In this work, a monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (icELISA) was established to detect tylosin and tilmicosin in milk and water samples. A sensitive and specific monoclonal antibody was prepared by rational designed hapten, which was achieved by directly oxidizing the aldehyde group on the side chain of tylosin to the carboxyl group. Under the optimized conditions, the linear range of icELISA for tylosin and tilmicosin were 1.3 to 17.7 ng/mL and 2.0 to 47.4 ng/mL, with half-maximal inhibition concentration (IC50) values of 4.7 and 9.6 ng/mL, respectively. The cross-reactivity with other analogues of icELISA was less than 0.1%. The average recoveries of icELISA for tylosin and tilmicosin ranged from 76.4% to 109.5% in milk and water samples. Besides, the detection results of icELISA showed good correlations with HPLC-MS/MS. The proposed icELISA was satisfied for rapid and specific screening of tylosin and tilmicosin residues in milk and water samples.

High affinity antibody based on a rationally designed hapten and development of a chemiluminescence enzyme immunoassay for quantification of Alternariol in fruit Juice, maize and flour.

Alternariol (AOH), a secondary metabolites of the genus Alternaria, is a genotoxic mycotoxin. Because the previous "Mannich antigen" for AOH readily underwent unstable induction, a new AOH hapten was designed for inducing a high-quality antibody against AOH using a conjugate of the AOH carboxymethyl derivative with a carrier protein as the immunogen. A competitive indirect chemiluminescence enzyme immunoassay (ciCLEIA) for AOH was optimized and showed good sensitivity (limit of detection 0.068 ng/mL), a linear range (0.11-1.23 ng/mL), and negligible cross-reactivity with analogues. Average rates of recovery from spiked samples (juice and cereal) were between 72.7% and 115.8%, with coefficients of variation <14.3%. Results from ciCLEIA correlated well with those of high-performance liquid chromatography coupled with tandem mass spectrometry, meaning the proposed method might be an effective screening tool for detection of AOH in food samples.

Ag+ doped into azo-linked conjugated microporous polymer for volatile iodine capture and detection of heavy metal ions.

We herein report the construction of a novel azo-linked conjugated microporous polymers (Ag@AzoTPE-CMP), which possesses permanent porous structure and Ag+ loading up of 7.62% in the skeleton as effective sorption sites. Ag@AzoTPE-CMP shows considerable adsorption capacity of iodine of 202 wt% in iodine vapor at 350 K. In addition, Ag@AzoTPE-CMP can effectively remove heavy ions from ethanol-water solution.

Thiophene-based porous organic networks for volatile iodine capture and effectively detection of mercury ion.

A series of conjugated microporous polymers containing thiophene-moieties (SCMP-COOH@1-3) was obtained by a homo-coupling polymerization reaction. Then the SCMP-COOH@1-3 were directly pyrolyzed without any templates to synthesize the porous carbon networks, named as SCMP-600@1, 2 and 3. SCMP-600@1-3 possess moderate BET surface area of 362-642 m2 g-1, have a permanent porous structure and plenty of sulfur and oxygen units in the skeletons as effective sorption sites, and display a high absorption performance for iodine vapour with an uptake up to 204 wt.%. In addition, SCMP-COOH@1-3 polymers can be used to effectively detect mercury ion from ethanol-water solution. Interestingly, under the same concentration of Hg2+ conditions, the detection ability of mercury ion of porous materials increased with the increase of the pore volumes and the specific surface.

Template-free synthesis of porous carbon from triazine based polymers and their use in iodine adsorption and CO2 capture.

A series of novel triazine-containing pore-tunable carbon materials (NT-POP@800-1-6), which was synthesized via pyrolysis of porous organic polymers (POPs) without any templates. NT-POP@800-1-6 possess moderate BET surface areas of 475-736 m2 g-1, have permanent porosity and plenty of nitrogen units in the skeletons as effective sorption sites, and display relatively rapid guest uptake of 56-192 wt% in iodine vapour in the first 4 h. In addition, all the samples exhibit the outstanding CO2 adsorption capacity of 2.83-3.96 mmol g-1 at 273 K and 1.05 bar. Furthermore, NT-POP@800-1-6 show good selectivity ratios of 21.2-36.9 and 3.3-7.5 for CO2/N2 or CH4/N2, respectively. We believe that our new building block design provides a general strategy for the construction of triazine-containing carbon materials from various extended building blocks, thereby greatly expanding the range of applicable molecules.

A multifunctional microporous metal-organic framework: efficient adsorption of iodine and column-chromatographic dye separation.

In this work, a multifunctional microporous metal-organic framework (MOF), [Cd(ABTC)(H2O)2(DMA)]·4DMA (JLNU-4; JLNU = Jilin Normal University; H4ABTC = 3,3',5,5'-azobenzenetetracarboxylic acid), has been synthesized based on the ligand H4ABTC under solvothermal conditions. JLNU-4 shows excellent uptake of iodine both in solution and in the vapor phase, owing to the existence of a microporous structure in JLNU-4. The adsorption kinetics during the process of iodine adsorption were analyzed via a series of qualitative and quantitative analyses, such as the Langmuir and Freündlich adsorption isotherms. In addition, according to UV/vis spectroscopy analysis and the colour variance of JLNU-4, the relatively small sized dye methylene blue (MB) could be efficiently adsorbed by JLNU-4, through size-exclusion effects. Particularly, JLNU-4 can serve as a column-chromatographic filler for the separation of dye molecules. Therefore, JLNU-4 is a multifunctional microporous MOF for iodine adsorption and column-chromatographic dye separation.

Conjugated microporous polymers with azide groups: a new strategy for postsynthetic fluoride functionalization and effectively enhanced CO2 adsorption properties.

A series of conjugated microporous polymers (CMPs) have been synthesized based on zinc-porphyrin building blocks. Azide groups incorporated within the pores of the CMPs were subjected to alkyne click conditions via a facile, one-step quantitative procedure, the resultant porous frameworks exhibited enhanced CO2 sorption properties.

Controlled synthesis of conjugated polycarbazole polymers via structure tuning for gas storage and separation applications.

A series of conjugated microporous polymers (CMPs) based on 1,3,6,8-tetrabromocarbazole (N4CMP-1-5) is synthesized via Suzuki cross-coupling or Sonogashira polycondensation. The porosity properties and surface area of these polymer networks can be finely tuned by using a linker with different geometries or strut length. These polymers show the Brunauer-Emmett-Tellerthe (BET) surface areas ranging from 592 to 1426 m2 g-1. The dominant pore sizes of the polymers on the basis of the different linker are located between 0.36 and 0.61 nm. Gas uptake increases with BET surface area and micropore volume, N4CMP-3 polymer can capture CO2 with a capacity of 3.62 mmol g-1 (1.05 bar and 273 K) among the obtained polymers. All of the polymers show high isosteric heats of CO2 adsorption (25.5-35.1 kJ mol-1), and from single component adsorption isotherms, IAST-derived ideal CO2/N2 (28.7-53.8), CO2/CH4 (4.6-5.2) and CH4/N2 (5.7-10.5) selectivity. Furthermore, N4CMPs exhibit the high CO2 adsorption capacity of 542-800 mg g-1 at 318 K and 50 bar pressure. These data indicate that these materials are a promising potential for clean energy application and environmental field.