Synthesizing Interpenetrated Triazine-based Covalent Organic Frameworks from CO2.

Crystalline triazine-based covalent organic frameworks (COFs) are aromatic nitrogen-rich porous materials. COFs typically show high thermal/chemical stability, and are promising for energy applications, but often require harsh synthesis conditions and suffer from low crystallinity. In this work, we propose an environmentally friendly route for the synthesis of crystalline COFs from CO2 molecules as a precursor. The mass ratio of CO2 conversion into COFs formula unit reaches 46.3 %. The synthesis consists of two steps; preparation of 1,4-piperazinedicarboxaldehyde from CO2 and piperazine, and condensation of the dicarboxaldehyde and melamine to construct the framework. The CO2 -derived COF has a 3-fold interpenetrated structure of 2D layers determined by powder X-ray diffraction, high-resolution transmission electron microscopy, and select-area electron diffraction. The structure shows a high Brunauer-Emmett-Teller surface area of 945 m2 g-1 and high stability against strong acid (6 M HCl), base (6 M NaOH), and boiling water over 24 hours. Post-modification of the framework with oxone has been demonstrated to modulate hydrophilicity, and it exhibits proton conductivity of 2.5×10-2  S cm-1 at 85 °C, 95 % of relative humidity.

Growth mechanisms and anisotropic softness-dependent conductivity of orientation-controllable metal-organic framework nanofilms.

Conductive metal-organic frameworks (cMOFs) manifest great potential in modern electrical devices due to their porous nature and the ability to conduct charges in a regular network. cMOFs applied in electrical devices normally hybridize with other materials, especially a substrate. Therefore, the precise control of the interface between cMOF and a substrate is particularly crucial. However, the unexplored interface chemistry of cMOFs makes the controlled synthesis and advanced characterization of high-quality thin films, particularly challenging. Herein, we report the development of a simplified synthesis method to grow "face-on" and "edge-on" cMOF nanofilms on substrates, and the establishment of operando characterization methodology using atomic force microscopy and X-ray, thereby demonstrating the relationship between the soft structure of surface-mounted oriented networks and their characteristic conductive functions. As a result, crystallinity of cMOF nanofilms with a thickness down to a few nanometers is obtained, the possible growth mechanisms are proposed, and the interesting anisotropic softness-dependent conducting properties (over 2 orders of magnitude change) of the cMOF are also illustrated.

Integrated Soft Porosity and Electrical Properties of Conductive-on-Insulating Metal-Organic Framework Nanocrystals.

A one-stone, two-bird method to integrate the soft porosity and electrical properties of distinct metal-organic frameworks (MOFs) into a single material involves the design of conductive-on-insulating MOF (cMOF-on-iMOF) heterostructures that allow for direct electrical control. Herein, we report the synthesis of cMOF-on-iMOF heterostructures using a seeded layer-by-layer method, in which the sorptive iMOF core is combined with chemiresistive cMOF shells. The resulting cMOF-on-iMOF heterostructures exhibit enhanced selective sorption of CO2 compared to the pristine iMOF (298 K, 1 bar, S CO 2 / H 2 ${{_{{\rm CO}{_{2}}/{\rm H}{_{2}}}}}$ from 15.4 of ZIF-7 to 43.2-152.8). This enhancement is attributed to the porous interface formed by the hybridization of both frameworks at the molecular level. Furthermore, owing to the flexible structure of the iMOF core, the cMOF-on-iMOF heterostructures with semiconductive soft porous interfaces demonstrated high flexibility in sensing and electrical "shape memory" toward acetone and CO2 . This behavior was observed through the guest-induced structural changes of the iMOF core, as revealed by the operando synchrotron grazing incidence wide-angle X-ray scattering measurements.

Non-contact real-time detection of trace nitro-explosives by MOF composites visible-light chemiresistor.

To create an artificial structure to remarkably surpass the sensitivity, selectivity and speed of the olfaction system of animals is still a daunting challenge. Herein, we propose a core-sheath pillar (CSP) architecture with a perfect synergistic interface that effectively integrates the advantages of metal-organic frameworks and metal oxides to tackle the above-mentioned challenge. The sheath material, NH2-MIL-125, can concentrate target analyte, nitro-explosives, by 1012 times from its vapour. The perfect band-matched synergistic interface enables the TiO2 core to effectively harvest and utilize visible light. At room temperature and under visible light, CSP (TiO2, NH2-MIL-125) shows an unexpected self-promoting analyte-sensing behaviour. Its experimentally reached limit of detection (∼0.8 ppq, hexogeon) is 103 times lower than the lowest one achieved by a sniffer dog or all sensing techniques without analyte pre-concentration. Moreover, the sensor exhibits excellent selectivity against commonly existing interferences, with a short response time of 0.14 min.

Cubic Iron Core-Shell Nanoparticles Functionalized to Obtain High-Performance MRI Contrast Agents.

Nanoparticles with SiO2 coating were synthesized to have a cubic iron core. These were found to have saturation magnetization very close to the highest possible value of any iron-containing nanoparticles and the bulk iron saturation magnetization. The in vitro toxicology studies show that they are highly biocompatible and possess better MRI contrast agent potential than iron oxide NPs.

A prediction model for early systemic recurrence in breast cancer using a molecular diagnostic analysis of sentinel lymph nodes: A large-scale, multicenter cohort study.

BACKGROUND: The one-step nucleic acid amplification (OSNA) assay can quantify the cytokeratin 19 messenger RNA copy number as a proxy for sentinel lymph node (SN) metastasis in breast cancer. A large-scale, multicenter cohort study was performed to determine the prognostic value of the SN tumor burden based on a molecular readout and to establish a model for the prediction of early systemic recurrence in patients using the OSNA assay. METHODS: SN biopsies from 4757 patients with breast cancer were analyzed with the OSNA assay. The patients were randomly assigned to the training or validation cohort at a ratio of 2:1. On the basis of the training cohort, the threshold SN tumor burden value for stratifying distant recurrence was determined with Youden's index; predictors of distant recurrence were investigated via multivariable analyses. Based on the selected predictors, a model for estimating 5-year distant recurrence-free survival was constructed, and predictive performance was measured with the validation cohort. RESULTS: The prognostic cutoff value for the SN tumor burden was 1100 copies/µL. The following variables were significantly associated with distant recurrence and were used to construct the prediction model: SN tumor burden, age, pT classification, grade, progesterone receptor, adjuvant cytotoxic chemotherapy, and adjuvant anti-human epidermal growth factor receptor 2 therapy. The values for the area under the curve, sensitivity, specificity, and accuracy of the prediction model were 0.83, 63.4%, 81.7%, and 81.1%, respectively. CONCLUSIONS: Using the OSNA assay, the molecular readout-based SN tumor burden is an independent prognostic factor for early breast cancer. This model accurately predicts early systemic recurrence and may facilitate decision-making related to treatment.

Pathological findings after third- and second-generation everolimus-eluting stent implantations in coronary arteries from autopsy cases and an atherosclerotic porcine model.

Pathological changes after third-generation drug-eluting stent implantation remain unclear. We compared the tissue responses of coronary arteries after the implantation of third-generation abluminal biodegradable-polymer everolimus-eluting stent (3rd EES) and second-generation durable-polymer EES (2nd EES) using autopsy specimens and an atherosclerotic porcine model. We compared the histology of stented coronary arteries obtained by autopsy performed 1-10 months after 3rd EES (n (number of cases) = 4, stent-implanted period of 3-7 months) and 2nd EES (n (number of cases) = 9, stent-implanted period of 1-10 months) implantations. The ratio of covered stent struts was higher with 3rd EESs than with 2nd EESs (3rd; 0.824 ± 0.032 vs. 2nd; 0.736 ± 0.022, p = 0.035). Low-density lipoprotein receptor knockout minipigs were stented with 3rd or 2nd EES in the coronary arteries and the stented regions were investigated. The fibrin deposition around the 2nd EES was more prominent. Additionally, higher density of smooth muscle cells was confirmed after the 3rd EES implantation. Pathological examination after the 3rd EES demonstrated a combination of less fibrin deposition and more rapid acquisition of well-developed neointima as compared to the 2nd EES at autopsy and the atherosclerotic porcine model.

A Dual-Ligand Porous Coordination Polymer Chemiresistor with Modulated Conductivity and Porosity.

Single-ligand-based electronically conductive porous coordination polymers/metal-organic frameworks (EC-PCPs/MOFs) fail to meet the requirements of numerous electronic applications owing to their limited tunability in terms of both conductivity and topology. In this study, a new 2D π-conjugated EC-MOF containing copper units with mixed trigonal ligands was developed: Cu3 (HHTP)(THQ) (HHTP=2,3,6,7,10,11-hexahydrotriphenylene, THQ=tetrahydroxy-1,4-quinone). The modulated conductivity (σ≈2.53×10-5  S cm-1 with an activation energy of 0.30 eV) and high porosity (ca. 441.2 m2 g-1 ) of the Cu3 (HHTP)(THQ) semiconductive nanowires provided an appropriate resistance baseline and highly accessible areas for the development of an excellent chemiresistive gas sensor.

Destruction of tumor mass by gadolinium-loaded nanoparticles irradiated with monochromatic X-rays: Implications for the Auger therapy.

Synchrotron generated monochromatic X-rays can be precisely tuned to the K-shell energy of high Z materials resulting in the release of the Auger electrons. In this work, we have employed this mechanism to destruct tumor spheroids. We first loaded gadolinium onto the surface of mesoporous silica nanoparticles (MSNs) producing gadolinium-loaded MSN (Gd-MSN). When Gd-MSN was added to the tumor spheroids, we observed efficient uptake and uniform distribution of Gd-MSN. Gd-MSN also can be taken up into cancer cells and localize to a site just outside of the cell nucleus. Exposure of the Gd-MSN containing tumor spheroids to monochromatic X-ray beams resulted in almost complete destruction. Importantly, this effect was observed at an energy level of 50.25 keV, but not with 50.0 keV. These results suggest that it is possible to use precisely tuned monochromatic X-rays to destruct tumor mass loaded with high Z materials, while sparing other cells. Our experiments point to the importance of nanoparticles to facilitate loading of gadolinium to tumor spheroids and to localize at a site close to the nucleus. Because the nanoparticles can target to tumor, our study opens up the possibility of developing a new type of radiation therapy for cancer.

Primary Intrahepatic Squamous Cell Carcinoma with Histological Collision of Adenocarcinoma and Squamous Cell Carcinoma: A Case Report.

BACKGROUND Cholangiocarcinoma is a rare, aggressive biliary tract malignancy. On histopathology, most tumors are adenocarcinomas, while squamous cell carcinoma of the biliary tract is extremely rare. CASE REPORT An 82-year-old male was admitted due to the detection of a space-occupying lesion at S6 of the liver. On abdominal dynamic computed tomography, there was an irregular mass with inhomogeneous density associated with mild delayed enhancement in the tumor's peripheral zone, measuring approximately 22×25 mm, at S6, with secondary dilated biliary ducts of B6. Endoscopic retrograde cholangiopancreatography showed a severe stricture at B6. Brush cytology of B6 was positive for both adenocarcinoma and squamous cell carcinoma. Furthermore, mucous brushing cytology of the papilla of Vater was also positive for adenocarcinoma. Finally, the preoperative diagnosis of primary intrahepatic cholangiocarcinoma, combined with a cancer of the papilla of Vater, was made. The patient underwent both extended right lobectomy and pancreaticoduodenectomy. Histological examination showed that the majority (>99%) of this liver tumor was composed of keratinizing squamous cell carcinoma. CONCLUSIONS Squamous cell carcinoma of the biliary tree is very rare, since the majority of biliary tree tumors are adenocarcinomas. Cholangiocarcinoma containing a squamous cell component has a poor prognosis. To the best of our knowledge, this is the first case report of a primary intrahepatic squamous cell carcinoma that presented as a solid tumor showing clear histological collision between adenocarcinoma and squamous cell carcinoma and was successfully treated with hepatic resection and achieved disease-free survival of more than one year.

Aggressive cribriform-morular variant of papillary thyroid carcinoma: Report of an unusual case with pulmonary metastasis displaying poorly differentiated features.

The cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is a rare morphologic entity in which metastasis rarely occurs. Until now, only three cases of metastasis by CMV-PTC have been reported. We present a rare sporadic case of CMV-PTC with multiple lung metastases in a 28-year-old female, 3 years after total thyroidectomy. The lung tumor was not encapsulated but well-circumscribed and showed a mixture of cribriform, papillary, and solid patterns of growth with necrosis. The tall columnar carcinoma cells did not display the typical nuclear features of PTC. Carcinoma cells were positive for thyroid transcription factor 1, paired-box gene 8, estrogen receptor, progesterone receptor, and adenomatous polyposis coli, and showed positive nuclear and cytoplasmic staining for ß-catenin. Carcinoma cells were negative for thyroglobulin and CDX-2, and the Ki-67 labeling index was 22.1%. This immunoprofile suggests a pathological diagnosis of metastasis by a CMV-PTC displaying poorly differentiated features. To the best of our knowledge, our case is the first report of CMV-PTC with pulmonary metastasis that was confirmed by histological and immunohistochemical examinations. The present case suggests that CMV-PTC with a high Ki-67 labeling index may cause visceral metastasis.

Atherosclerotic Plaque Component as a Risk Factor for Distal Embolization During Percutaneous Coronary Intervention　- Pathology of Tissue Obtained by Distal Protection Device.

BACKGROUND: Embolism during percutaneous coronary intervention (PCI) causes microcirculation impairment. The aim of this study was to clarify the relationship between the pathological characteristics of tissue captured by distal protection device (DPD) and amount of tissue accumulated in DPD. Methods and Results: A total of 671 consecutive lesions in PCI using DPD were examined. The amount of necrotic debris, fibrous tissue, calcified particle, platelet thrombus and organized thrombus in the DPD baskets was histologically evaluated. The DPD tissue amount was assessed semi-quantitatively, and the relationship between the captured DPD tissue characteristics and tissue amount was investigated. On pathology, 40.7% of the lesions had necrotic debris, 41.4% had fibrous tissue, and 18.0% had calcified particle. The prevalence of lesions in patients with acute coronary syndrome (ACS) was 62.1%. Tissue amount score distribution was as follows: score 1 (tissue invisible), 3.9%; score 2 (tissue clinging to the basket), 52.0%; score 3 (tissue accumulated at the bottom of the basket), 38.5%; and score 4 (tissue accumulated in more than half of the basket), 5.7%. On multivariate analysis, necrotic debris and fibrous tissue were associated with greater tissue amount as well as clinical presentation of ACS. CONCLUSIONS: The presence of atherosclerotic plaque component, such as necrotic debris and fibrous tissue, might be a risk for distal embolism during PCI.

A rare case of ectopic papillary thyroid carcinoma transformed into squamous cell carcinoma.

A rare case of a metastatic ectopic papillary thyroid carcinoma (PTC) of the lung that transformed into a squamous cell carcinoma (SCC) that resembles pulmonary SCC is reported. A subcutaneous ectopic PTC in the left anterior neck area, together with a normal thyroid gland, were excised. The ectopic PTC showed thyroglobulin, TTF-1 and PAX-8 immunoreactivity and a BRAF V600E mutation. During the post-operative follow-up period, a rapidly growing 2 cm nodular lesion in the lower left lobe of the lung was detected. The lung tumor consisted of solid sheets and nests of squamous cells but without the nuclear features of PTC. Neither papillary nor follicular structures of cancer cells were identified. Carcinoma cells were positive for TTF-1, PAX-8, p40, CK14, and p63, while showing a high Ki-67 labeling index and a BRAF V600E mutation. These results support our interpretation of a PTC that originated from ectopic thyroid tissue in the left anterior neck and that developed a lung metastasis showing squamous cell differentiation.

Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Postsynthetic Approach.

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous materials that are constructed by the assembly of organic building blocks linked via covalent bonds. Several strategies have been developed for the construction of new COF structures; however, a facile approach to fabricate hierarchical COF architectures with controlled domain structures remains a significant challenge, and has not yet been achieved. In this study, a dynamic covalent chemistry (DCC)-based postsynthetic approach was employed at the solid-liquid interface to construct such structures. Two-dimensional imine-bonded COFs having different aromatic groups were prepared, and a homogeneously mixed-linker structure and a heterogeneously core-shell hollow structure were fabricated by controlling the reactivity of the postsynthetic reactions. Solid-state nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) confirmed the structures. COFs prepared by a postsynthetic approach exhibit several functional advantages compared with their parent phases. Their Brunauer-Emmett-Teller (BET) surface areas are 2-fold greater than those of their parent phases because of the higher crystallinity. In addition, the hydrophilicity of the material and the stepwise adsorption isotherms of H2O vapor in the hierarchical frameworks were precisely controlled, which was feasible because of the distribution of various domains of the two COFs by controlling the postsynthetic reaction. The approach opens new routes for constructing COF architectures with functionalities that are not possible in a single phase.

Initial pathological responses of second-generation everolimus-eluting stents implantation in Japanese coronary arteries: Comparison with first-generation sirolimus-eluting stents.

BACKGROUND: The clinical benefit of second-generation drug-eluting stents (2nd DES) has been established, compared to first-generation drug-eluting stents (1st DES). However, pathological response after 2nd DES implantation remains unclear, particularly in the Japanese population. METHODS: Using specimens obtained by autopsy, we compared the histology between 2nd DES (41 sections) and 1st DES (38 sections) lesions within 1 year after stent implantation to evaluate early tissue reaction in Japanese patients. Stent segments were fixed with 10% buffered formalin and embedded in plastic, followed by hematoxylin-eosin and Masson's trichrome staining. Ratio of covered stent struts was calculated, and the area of fibrin deposition was morphometrically evaluated. The degree of inflammation around struts was examined semi-quantitatively (score 0-3). RESULTS: The ratio of covered struts and mean fibrin area of 2nd DES were 0.69±0.05 and 658.0±173.4µm2. Those of 1st DES were 0.44±0.12 and 3107.5±1405.9µm2. In the 2nd DES, there was significantly less fibrin deposition and a higher covered struts ratio. The inflammation score was significantly lower in 2nd DESs compared to 1st DESs (1.02±0.16 vs. 1.19±0.54, p<0.05). CONCLUSIONS: Histopathological analysis showed advanced healing process in 2nd DES compared with 1st DES lesions. These results are consistent with clinical beneficial outcome of 2nd DES implantation.

A rare case of poorly differentiated thyroid carcinoma probably arising from a nodular goiter.

BACKGROUND: Some poorly differentiated thyroid carcinomas (PDTC) arise from pre-existing, well-differentiated carcinomas of follicular cell origin; however, others most likely arise de novo. The case of a PDTC adjacent to a pre-existing nodular goiter is very rare. CASE PRESENTATION: A patient had a PDTC, a widely invasive, cellular tumor with cells that lacked the nuclear features of a papillary thyroid carcinoma. Carcinoma cells were arranged in trabecular, solid, and microfollicular histological patterns and displayed high mitotic activity. A nodule partially encapsulated in a thick fibrous capsule was found adjacent to the PDTC. The nodule was composed of small or dilated follicles, without papillary carcinoma-like nuclear features, that were consistent with a nodular goiter. The PDTC showed a high Ki-67 labeling index and an NRAS gene mutation (codon 61, Q61K). CONCLUSION: These results support our diagnosis of a PDTC, probably arising from a nodular goiter.

Regioisomer effects of [70]fullerene mono-adduct acceptors in bulk heterojunction polymer solar cells.

Despite numerous organic semiconductors being developed during the past decade, C70 derivatives are predominantly used as electron acceptors in efficient polymer solar cells (PSCs). However, as-prepared C70 mono-adducts intrinsically comprise regioisomers that would mask individual device performances depending on the substituent position on C70. Herein, we separate the regioisomers of C70 mono-adducts for PSC applications for the first time. Systematic investigations of the substituent position effect using a novel symmetric C70 mono-adduct ([70]NCMA) and a prevalent, high-performance one ([70]PCBM) reveals that we can control the structures of the blend films with conjugated polymers and thereby improve the PSC performances by regioisomer separation. Our approach demonstrates the significance of exploring the best-matching regioisomer of C70 mono-adducts with high-performance conjugated polymers, which would achieve a remarkable progress in PSC devices.

Enhanced and Optically Switchable Proton Conductivity in a Melting Coordination Polymer Crystal.

The melting behavior of a coordination polymer (CP) crystal was utilized to achieve enhanced and optically switchable proton conductivity in the solid state. The strong acid molecules (triflic acid) were doped in one-dimensional (1D) CP, [Zn(HPO4 )(H2 PO4 )2 ](ImH2 )2 (ImH2 =monoprotonated imidazole) in the melt state, and overall enhancement in the proton conductivity was obtained. The enhanced proton conductivity is assigned to increased number of mobile protons and defects created by acid doping. Optical control over proton conductivity in the CP is achieved by doping of the photo acid molecule pyranine into the melted CP. The pyranine reversibly generates the mobile acidic protons and local defects in the glassy state of CP resulting in the bulk switchable conductivity mediated by light irradiation. Utilization of CP crystal in liquid state enables to be a novel route to incorporate functional molecules and defects, and it provides a tool to control the bulk properties of the CP material.

Mechanical Alloying of Metal-Organic Frameworks.

The solvent-free mechanical milling process for two distinct metal-organic framework (MOF) crystals induced the formation of a solid solution, which is not feasible by conventional solution-based syntheses. X-ray and STEM-EDX studies revealed that performing mechanical milling under an Ar atmosphere promotes the high diffusivity of each metal ion in an amorphous solid matrix; the amorphous state turns into the porous crystalline structure by vapor exposure treatment to form a new phase of a MOF solid solution.