CT Findings of Hepatic Metastasis from Hepatoid Adenocarcinoma of the Rectum Mimicking Hepatocellular Carcinoma: A Case Report.

Hepatoid adenocarcinoma (HAC) is a rare form of adenocarcinoma that is diagnosed based on immuno-histochemical findings reminiscent of hepatocellular carcinoma (HCC). The clinical characteristics of HAC include increased levels of serum alpha-fetoprotein and a poor prognosis due to early liver metastasis. In particular, diagnosing liver metastasis of HAC can be challenging owing to radiological findings similar to those of HCC. Although HAC can occur in various organs, the stomach is the most common site. We present the case of a 64-year-old femalewho presented with multiple tumors in the liver. During subsequent examination, rectal cancer was identified and diagnosed as HAC through a biopsy. Herein, we report this case along with a literature review.

Peripheral Arterial Stiffness Increases the Risk of Progression of Renal Disease in Type 2 Diabetic Patients.

Aims: Our aim was to investigate the effects of peripheral arterial stiffness on the risk of progression of renal disease in patients with type 2 diabetes (T2D). Methods: This was a single center, retrospective cohort study. Brachial-ankle pulse wave velocity (baPWV) tests were performed on T2D patients in 2015. Increased arterial stiffness was defined as baPWV of ≥ 1800 cm/s. We applied criteria for progression of renal disease according to EMPA-REG OUTCOME trial. Results: In total, 186 patients were enrolled in the final study. The mean age was 59.1 years and male:female ratio was 1.73:1. Thirteen (7%) patients progressed to renal disease during the average follow-up time of 35.3 months. In particular, the risk of progression to macroalbuminuria was significantly higher in the baPWV ≥ 1800 cm/s group (HR 6.216, p = 0.020). Individuals with a baPWV of ≥ 1800 cm/s (when comparisons were adjusted for age, sex, blood pressure, diabetes duration, eGFR, and use of renin-angiotensin system inhibitors) had a significantly higher risk of the progression of renal disease (HR = 8.480, p = 0.014). Conclusion: These results suggest that peripheral arterial stiffness (baPWV ≥ 1800 cm/s) may be a risk factor for the progression of renal disease in T2D patients.

Metal-free, polyether-mediated H2-release from ammonia borane: roles of hydrogen bonding interactions in promoting dehydrogenation.

Polyetheral additives were found to be efficient promoters to enhance the rate of H2-release from ammonia borane (AB) at various temperatures. In particular, tetraethylene glycol dimethyl ether (T4EGDE, 29 wt% relative to AB + T4EGDE) exhibited significantly improved activities for AB dehydrogenation, with the material-based hydrogen storage capacity of 10.3 wt% at 125 °C within 40 min. In situ FT-IR spectroscopy indicated the formation of B-(cyclodiborazanyl)amino-borohydride (BCDB), borazine, and µ-aminodiborane as gaseous byproducts. In addition, (11)B nuclear magnetic resonance (NMR) spectroscopy further revealed that diammoniate of diborane (DADB) was initially formed to give polyaminoborane as liquid and/or solid spent-fuel, consistent with previous reports. Density Functional Theory (DFT) calculations suggested that hydrogen bonding interactions between AB and a polyetheral promoter initially played an important role in increasing the reactivity of B-H bonds of AB by transferring electron density from oxygen atoms of the promoter into B-H bonds of AB. These partially activated, hydridic B-H bonds were proposed to help promote the formation of diammoniate of diborane (DADB), which is considered as a reactive intermediate, eventually enhancing the rate of H2-release from AB. In addition, our in situ solid state (11)B magic angle spinning (MAS) NMR measurements further confirmed that the rate of DADB formation from AB with a small quantity of T4EGDE was found to be much faster than that of pristine AB even at 50 °C. This metal-free method for H2-release from AB with an added, small quantity of polyethers would be helpful to develop feasible hydrogen storage systems for long-term fuel cell applications.

Effect of particle size of PtRu nanoparticles embedded in WO3 on electrocatalysis.

Size-controlled PtRu nanoparticles embedded in WO3 were prepared by simultaneous multigun sputtering on pure targets of Pt, Ru, and WO3. The mean diameter of the PtRu nanoparticles, as confirmed by high-resolution transmission electron microscopy, can be varied from -2.3 to -3.6 nm by varying the RF power ratio of PtRu and WO3. On the basis of transmission electron diffraction results for the PtRu nanoparticles embedded in WO3, it was confirmed that PtRu exists as an alloy metal phase, whereas the WO3 matrix is present as an amorphous phase. Size-controlled PtRu/WO3 electrodes were found to exhibit unique electronic properties depending on their size, which affected the potential of zero total charge and the methanol oxidation reaction. The mass activity of PtRu/WO3 for methanol oxidation was determined by the interplay of the surface electronic factors at the metal-solution interface; the oxophilicity of the nanoparticles increased with decreasing particle size.

Supported core@shell electrocatalysts for fuel cells: close encounter with reality.

Core@shell electrocatalysts for fuel cells have the advantages of a high utilization of Pt and the modification of its electronic structures toward enhancement of the activities. In this study, we suggest both a theoretical background for the design of highly active and stable core@shell/C and a novel facile synthetic strategy for their preparation. Using density functional theory calculations guided by the oxygen adsorption energy and vacancy formation energy, Pd3Cu1@Pt/C was selected as the most suitable candidate for the oxygen reduction reaction in terms of its activity and stability. These predictions were experimentally verified by the surfactant-free synthesis of Pd3Cu1/C cores and the selective Pt shell formation using a Hantzsch ester as a reducing agent. In a similar fashion, Pd@Pd4Ir6/C catalyst was also designed and synthesized for the hydrogen oxidation reaction. The developed catalysts exhibited high activity, high selectivity, and 4,000 h of long-term durability at the single-cell level.

Role of electronic perturbation in stability and activity of Pt-based alloy nanocatalysts for oxygen reduction.

The design of electrocatalysts for polymer electrolyte membrane fuel cells must satsify two equally important fundamental principles: optimization of electrocatalytic activity and long-term stability in acid media (pH <1) at high potential (0.8 V). We report here a solution-based approach to the preparation of Pt-based alloy with early transition metals and realistic parameters for the stability and activity of Pt(3)M (M = Y, Zr, Ti, Ni, and Co) nanocatalysts for oxygen reduction reaction (ORR). The enhanced stability and activity of Pt-based alloy nanocatalysts in ORR and the relationship between electronic structure modification and stability were studied by experiment and DFT calculations. Stability correlates with the d-band fillings and the heat of alloy formation of Pt(3)M alloys, which in turn depends on the degree of the electronic perturbation due to alloying. This concept provides realistic parameters for rational catalyst design in Pt-based alloy systems.

One-pot synthesis of intermetallic electrocatalysts in ordered, large-pore mesoporous carbon/silica toward formic acid oxidation.

This study describes the one-pot synthesis and single-cell characterization of ordered, large-pore (>30 nm) mesoporous carbon/silica (OMCS) composites with well-dispersed intermetallic PtPb nanoparticles on pore wall surfaces as anode catalysts for direct formic acid fuel cells (DFAFCs). Lab-synthesized amphiphilic diblock copolymers coassemble hydrophobic metal precursors as well as hydrophilic carbon and silica precursors. The final materials have a two-dimensional hexagonal-type structure. Uniform and large pores, in which intermetallic PtPb nanocrystals are significantly smaller than the pore size and highly dispersed, enable pore backfilling with ionomers and formation of the desired triple-phase boundary in single cells. The materials show more than 10 times higher mass activity and significantly lower onset potential for formic acid oxidation as compared with commercial Pt/C, as well as high stability due to better resistivity toward CO poisoning. In single cells, the maximum power density was higher than that of commercial Pt/C, and the stability highly improved, compared with commercial Pd/C. The results suggest that PtPb-based catalysts on large-pore OMCSs may be practically applied as real fuel cell catalysts for DFAFC.

Role of Small Pd Ensembles in Boosting CO Oxidation in AuPd Alloys.

We present a theoretical explanation on how PdAu alloy catalysts can enhance the oxidation of CO molecules based on density functional theory calculations of CO adsorption and oxidation on AuPd/Pd(111) surfaces. Our study suggests that the enhanced activity is largely attributed to the possible existence of "partially-poisoned" Pd ensembles that accommodate fewer CO molecules than Pd atoms. Whereas the oxidation of preadsorbed CO is likely governed by O2 trapping, our study shows that small Pd ensembles such as dimers and compact trimers tend to provide more active sites than larger ensembles; CO adsorbed on a Pd monomer is found to react hardly with O2 to form CO2. In addition, we find the tendency of CO-induced Pd agglomeration, which may in turn facilitate CO oxidation by creating more dimers and compact trimers as compared with the adsorbate-free surface where monomers are likely prevailing.

Enhanced stability and activity of Pt-Y alloy catalysts for electrocatalytic oxygen reduction.

We report Pt-based alloys with early transition metals. Significant electrocatalysis occurs during oxygen reduction reaction (ORR) at the Pt-Y alloy electrodes, and the extent depends on the alloy composition. The Pt-Y alloy electrode activity is related to the d-band center position, and the lattice strain and stability for oxygen reduction reaction.

Multilayered Pt/Ru nanorods with controllable bimetallic sites as methanol oxidation catalysts.

A physical synthesis of multilayered Pt/Ru nanorods with controllable bimetallic sites as methanol oxidation catalysts is reported for the first time. The novel nanorods were synthesized via the oblique angle deposition method, deposited prior to the formation of each individual noble metal layer, in a sequential fashion. It has been shown that the oblique angle deposition controls the morphology and electrochemical properties of the resultant nanostructures. Sequentially the multilayered nanorods comprising Pt and Ru segments exhibited superior electrocatalytic activity when compared to equivalent monometallic Pt nanorods with respect to methanol electrooxidation reaction in an acidic medium. Moreover, it has been established that the electrochemical process takes place at the Pt/Ru nanorods followed the bifunctional mechanism. The relative rates of reaction, recorded using chronoamperometry, show a linear relationship between the long-time current density and the number of Pt/Ru interfaces. Interestingly, the best catalyst for methanol oxidation was found to the surface of bimetallic Pt/Ru nanorods produced by the heat treatments via the so-called electronic effect. This reflects the fact that the ensemble effects of combined bifunctional and electronic effects via second elements could be expected in methanol oxidation reactions. Electrocatalytic activities correlate well with bimetallic pair sites and electronic properties analyzed by X-ray photoemission spectroscopy and X-ray absorption near-edge structure.

Facile synthesis of highly active and stable Pt-Ir/C electrocatalysts for oxygen reduction and liquid fuel oxidation reaction.

A facile room temperature synthesis technique has been developed for Pt-Ir/C electrocatalysts for applications to low-temperature fuel cells. The prepared Pt(x)Ir(y) electrocatalyst was highly stable and active toward the oxygen reduction reaction (ORR), as well as liquid fuel oxidation reaction with high CO tolerance.

PtRu nano-dandelions on thiolated carbon nanotubes: a new synthetic strategy for supported bimetallic core-shell clusters on the atomic scale.

Core-shell PtRu clusters resembling dandelions were formed on thiolated carbon nanotubes by the difference in bond strength with surface thiol groups between Pt and Ru single atoms. The formation mechanism was clearly understood using a different release timing concept based on EXAFS and XPS analyses during heat treatment.

Modification of Au nanoparticles dispersed on carbon support using spontaneous deposition of Pt toward formic acid oxidation.

This work presents formic acid oxidation on Pt deposits on Au nanoparticles dispersed on Vulcan XC-72R. The Pt deposits were produced using spontaneous deposition method contacting the Au nanoparticles with solutions containing Pt complex ions in various concentrations. The Pt deposits were characterized using CO stripping coulometry, X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectroscopy. When the Pt concentration is 10(-5)-10(-4) M, the Pt deposits are nanoislands of monatomic height. In the concentration range of 10(-4)-10(-3) M, the Pt deposits are most likely two-layer-thick nanofeatures. As Pt concentration increases further, the deposits become wider and thicker. Voltammetric behavior of Pt deposits reveals that on Pt deposits, dehydrogenation path is activated at the expense of poison-forming dehydration path. Furthermore, chronoamperometric measurement of the catalytic activity of Pt deposits supports that the two-layer-thick Pt deposits are most efficient in formic acid oxidation among the studied Pt deposits on Au nanoparticles. The enhancement factor of the particular Pt deposits is 2 in terms of turnover frequency, compared with a commercial Pt catalyst. Details are discussed in conjunction with Pt deposits on Au(111).

Concentration of vascular endothelial growth factor after intracameral bevacizumab injection in eyes with neovascular glaucoma.

PURPOSE: To study the concentration of vascular endothelial growth factor (VEGF) in the aqueous humor before and after intracameral injection of bevacizumab in eyes with neovascular glaucoma, and to detect the duration of an anti-VEGF effect of bevacizumab in the anterior chamber. METHODS: In this prospective interventional case series, 1.25 mg of bevacizumab was injected into the anterior chamber of five eyes in five neovascular glaucoma patients. Aqueous humor samples were obtained just before intracameral injection of bevacizumab and two weeks after injection. The concentrations of VEGF in the aqueous humor were measured using ELISA. To investigate corneal endothelial damage after intrecameral bevacizumab injection, specular microscopy was performed before injection and two weeks after injection. Slit lamp photo and iris fluorescent angiography was performed to determine the regression of iris neovascularization. RESULTS: After injection, substantial regression of neovascularization or fluorescein leakage was seen in all treated eyes. The VEGF concentrations in the aqueous humor in eyes with NVG were 1181.8 + or - 1248.3 pg/mL before intracameral injection of bevacizumab. Two weeks after injection, the VEGF concentrations decreased to 33.2 + or - 12.2 pg/mL (p=0.04, Wilcoxon signed rank test). There were no significant changes in IOP or corneal endothelial cells. CONCLUSIONS: Intracameral bevacizumab injection can remarkably reduce iris neovascularization in neovascular glaucoma patients. VEGF levels were significantly decreased two weeks after injection and corneal toxicity was not observed during short term follow-up.

Electrocatalytic oxidation of formic acid and methanol on Pt deposits on Au(111).

This work presents characteristics of Pt deposits on Au(111) obtained by the use of spontaneous deposition and investigated by electrochemical scanning tunneling microscopy (EC-STM). On such prepared and STM characterized Au(111)/Pt surfaces, we studied electrocatalytic oxidation of formic acid and methanol. We show that the first monatomic layer of Pt displays a (square root 3 x square root 3)R30 degrees surface structure, while the second layer is (1 x 1). After prolonged deposition, multilayer Pt deposits are formed selectively on Au(111) surface steps and are 1-20 nm wide and one to five layers thick. On the optimized Au(111)/Pt surface, formic acid oxidation rates are enhanced by a factor of 20 compared to those of pure Pt(111). The (square root 3 x square root 3)R30 degrees-Pt yields very low methanol oxidation rates, but the rates increase significantly with further Pt growth.

Surface characterization of argon-plasma-modified perfluorosulfonic acid membranes.

The perfluorosulfonic acid membranes which are used in direct methanol fuel cells were modified with argon plasma under various conditions, and the physicochemical and transport properties of the resulting membranes were investigated using various analytical techniques. The plasma treatment was found to change the surface morphology and physicochemical properties of the membranes. The surface roughness of the membranes was increased by the etching effect of plasma. From the FTIR and XPS analyses, the incorporation of new oxygen functionalities, such as the peroxide group, was confirmed. The breakage of both the sulfonic acid groups and ether linkages were also found to cause an increase in the equivalent weight of the modified skin layer of the membrane. The incident water contact angle of the modified membrane in a dry state decreased with an increased plasma treatment, because of the hydrophilic groups that developed on the membrane surface. The time-dependent water contact angle, however, increased in proportion to the extent of the plasma treatment, due to the reduced concentration of sulfonic acid groups. Although the equilibrium water uptake of the modified membrane was almost invariable because of the negligible thickness of the modified skin layer, the transport properties of the membrane such as methanol permeability and proton conductivity were significantly reduced.