Pt-Co Alloy Nanoparticles on a γ-Al2 O3 Support: Synergistic Effect between Isolated Electron-Rich Pt and Co for Automotive Exhaust Purification

There is interest in minimizing or eliminating the use of Pt in catalysts by replacing it with more widely abundant and cost-effective elements. The alloying of Pt with non-noble metals is a potential strategy for reducing Pt use because interactions between Pt and non-noble metals can modify the catalyst structure and electronic properties. Here, a γ-Al₂ O₃ -supported bimetallic catalyst [Pt(0.1)Co(1)/Al₂ O₃ ] was prepared which contained 0.1 wt % Pt and 1 wt % Co and thus featured an extremely low Pt : Co ratio (<1 : 30 mol/mol). The Pt and Co in this catalyst formed alloy nanoparticles in which isolated electron-rich Pt atoms were present on the nanoparticle surface. The activity of this Pt(0.1)Co(1)/Al₂ O₃ catalyst for the purification of automotive exhaust was comparable to the activities of 0.3 and 0.5 wt % Pt/γ-Al₂ O₃ catalysts. Electron-rich Pt and metallic Co promoted activation of NO_x and oxidization of CO and hydrocarbons, respectively. This strategy of tuning the surrounding structure and electronic state of a noble metal by alloying it with an excess of a non-noble metal will enable reduced noble metal use in catalysts for exhaust purification and other environmentally important reactions.

P107 Predictors of increased d-dimer level at follow-up period after transcatheter aortic valve implantation.Is oral anticoagulation therapy better?

Background

Recently, there are some reports that hypo-attenuated leaflet thickening (HALT) following transcatheter aortic valve implantation (TAVI) is incidentally detected by multi-slice computed tomography. It is believed that valve thrombosis causes HALT, because oral anticoagulation therapy (OAC) is effective for HALT regression. Furthermore, it is reported that d-dimer level increases in patients with HALT, and might be a key biomarker to detect HALT.

Purpose

We sought to investigate the predictors related to increased d-dimer level at 6 months after follow-up TAVI.

Methods

We enrolled 124 consecutive patients who underwent successful TAVI between 2016 and 2018. Study patients were classified into two groups according to antithrombotic therapy resume (OAC therapy or anti-platelet therapy).We set the primary endpoint as the d-dimer levels at 6 months after TAVI. To evaluate the risks of the primary endpoint, we employed a multivariable linear regression model, setting the primary endpoint as an objective variable and patient and clinical backgrounds as explanatory variables. Furthermore, we set the secondary endpoint as one-year bleeding event.

Results

The median age of patients was 83 years old (quartile 80-87). Patients who had taken OAC at 6 months follow-up after TAVI were 29.8%. The median d-dimer level at 6 months after TAVI was 1.3 (1.0-2.2) µg/ml, and OAC group had statistically lower d-dimer level at 6 months follow-up than those in non-OAC group (p = 0.020). Uni-variable liner regression model demonstrated that increased d-dimer level at follow-up had significant relationship with large effective orifice area (EOA) (p = 0.002) and low left ventricular ejection fraction (LVEF) (p = 0.048) after TAVI. Furthermore, large EOA (p = 0.003) and OAC therapy (p = 0.027) were independently associated with increased d-dimer level in multivariate analysis. Kaplan-Meier estimates revealed that there were no significant difference regarding one-year bleeding event between OAC group and non-OAC group (long-rank p = 0.167).

Conclusions

This study suggests that large EOA after TAVI is associated with increased d-dimer levels at 6 months after TAVI, and OAC therapy might have a potential to decrease d-dimer level after TAVI without increase of bleeding events.

Abstract P107 Figure: One-year bleeding event

P3693Self-expandable transcatheter aortic valve implantation is associated with frequent periprocedural stroke detected by diffusion-weighted magnetic resonance imaging -Insight from propensity score match

Background

Little evidence is available regarding the risk of peri-procedural stroke detected by diffusion-weighted magnetic resonance imaging (DW-MRI) after transcatheter aortic valve implantation (TAVI). Our purpose was to evaluate stroke risk after TAVI using DW-MRI by enrolling consecutive patients who underwent transfemoral TAVI and post-procedural DW-MRI.

Methods

We prospectively enrolled 113 consecutive patients who underwent transfemoral TAVI and post-procedural DW-MRI. We used balloon-expandable valves as first-line therapy and selected self-expandable valves only for patients with narrow sinotubular junctions or annuli. We set the primary endpoint as the number of high intensity areas (HIA) detected by DW-MRI regardless of the size of the area. To evaluate the risks of the primary endpoint, we employed a multivariable linear regression model, setting the primary endpoint as an objective variable and patient and clinical backgrounds as explanatory variables. In addition, the relationship between valve type and the number of HIAs on DW-MRI was also confirmed by the propensity score matching analysis to evaluate the robustness of the result, using a multivariable linear regression model with the protocol described in the previous manuscript. Shortly, the propensity score was calculated with a logistic regression model by setting the treatment as the response variable and baseline characteristics and procedural information that were significantly different between 2 groups (balloon expandable and self-expandable) as explanatory variables, which included age, estimated glomerular filtration rate, oversizing rate, and BAV before THV deployment.

Results

Median patient age was 84 years, and 36.3% were men. Ninety-three patients underwent balloon-expandable TAVI and 20 underwent self-expandable TAVI. Symptomatic stroke occurred in 6 (5.3%) whereas asymptomatic stroke occurred in 59 (52.2%) patients. The incidence of symptomatic and total stroke was higher in patients who underwent self-expandable TAVI than those who underwent balloon-expandable TAVI (30.0% vs 0.0%, p<0.001 and 90.0% vs 50.5%, p=0.001, respectively). A multivariable linear regression model demonstrated an increased primary endpoint when self-expandable TAVI was performed (p<0.001). The other covariates had no significant relationship to the primary endpoint. Akaike information criterion-based stepwise statistical model selection revealed that valve type was the only explanatory variable for the best predictive model. This result was also confirmed with the propensity score matching analysis (estimate, 2.359; 95% CI, 0.426–4.292; p=0.019) after adjustments of propensity score, in which 28 patients were matched (n=14 in each group).

Conclusions

Self-expandable valves were associated with increased numbers of HIA on DW-MRI after TAVI in patients with severe aortic stenosis.

P4158Marked impairment of endothelium-dependent digital vasodilatations in patients with microvascular angina compared with those with vasospastic angina

Background/Introduction

Nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) factor are the major endothelium-derived relaxing factors. NO plays an important role in conduit arteries, while the importance of EDH factor increases as the vessel size decrease in patients with microvascular angina (MVA) compared with those with vasospastic angina (VSA) remains to be fully elucidated.

Purpose

We evaluated the roles of NO and EDH factor in conduit (brachial) arteries and resistance (digital) arteries of the patients with MVA, VSA and comorbid MVA+VSA patients.

Methods

We enrolled 39 patients who underwent diagnostic cardiac catheterization and divided them into 3 groups based on acetylcholine (ACh) provocation test, index of microcirculation resistance (IMR), and coronary flow reserve (CFR); MVA (N=9, mean age 59.9±3.5 years), VSA (N=12, mean age 61.3±1.8 years), and comorbid MVA+VSA (N=18, mean age 64.0±2.2 years). Endothelium-dependent brachial and digital vasodilatations in response to intra-arterial infusion of bradykinin (BK, 25, 50, and 100 ng/min for 2 min) were simultaneously measured by ultrasonography and peripheral arterial tonometry, respectively. Measurements were repeated after oral administration of aspirin (486 mg) and intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA, 8μmol/min for 5 min) in order to inhibit the effects of vasodilator prostaglandins and NO, respectively. Finally, endothelium-independent brachial and digital vasodilatations in response to sublingual nitroglycerin (NTG, 0.3 mg) were measured in the same manner.

Results

In the brachial artery, dose-dependent vasodilatations to BK were comparable among the 3 groups, and L-NMMA equally attenuated the responses to BK (Figure 1). Endothelium-independent brachial vasodilatation in response to NTG was also comparable among the 3 groups. Surprisingly, dose-dependent digital vasodilatations to BK were almost absent in MVA patients compared with VSA or comorbid MVA+VSA group (Figure 2). Furthermore, the digital vasodilatations were unaffected by L-NMMA in VSA group, but were significantly reduced in comorbid MVA+VSA group (VSA, 16.8±15.1% vs. MVA+VSA, −0.23±6.2%, P<0.05), suggesting reduced EDH and compensatory role of NO in the latter group. In contrast, endothelium-independent digital vasodilatation in response to NTG was comparable among the 3 groups.

The main results of this study

Conclusions

These results provide the first evidence that endothelium-dependent digital vasodilatations (both NO and EDH factor) are markedly impaired in MVA patients compared with VSA or comorbid MVA+VSA patients, whereas the responses are comparable in the brachial artery among the 3 groups, suggesting the involvement of severe endothelial dysfunction in the pathogenesis of MVA.

Quantitative analysis of mammalian chromosome by scanning transmission soft X-ray microscopy

Soft X-ray spectromicroscopy was applied to study the quantitative distribution of DNA and protein in a mammalian chromosome at the spatial resolution of 100 nm. The quantities of DNA and protein were evaluated using 1s-π* transition in the NEXAFS spectra at the nitrogen K absorption edge. DNA was not uniformly distributed in the chromosome and DNA/protein ratio was less than 0.497. The present analysis revealed the clues to identify other molecules that contribute to the absorption spectrum of the sample. The results suggested that accumulation of the absorption spectra of relevant molecules would support the refinement of the analysis.

Comparative phenology of dormant Japanese pear (Pyrus pyrifolia) flower buds: a possible cause of 'flowering disorder'

Mild winters influenced by global warming have increased the incidence of erratic flowering ('flowering disorder') in Japanese pear (Pyrus pyrifolia Nakai) trees in Japan. To discover how, when and what kind of disorder/damage occur in pear flower buds, we observed axillary flower buds of two cultivars, 'Kosui' (a mid-chill cultivar) and 'Niitaka' (a high-chill cultivar), grown at five locations. We focused on the phenology from autumn 2015 to spring 2016, when temperatures were higher than for average years, especially from September to January, and large fluctuations occurred due to El Niño. During the blooming season in the spring of 2016, both the percentage of blooming flower buds and the number of florets per flower bud decreased in trees located at lower latitudes (with lower chilling accumulation) with a more severe problem in 'Niitaka' than in 'Kosui'. As shown by forcing excised shoots, the onset and release of endodormancy occurred earlier in 'Kosui' than 'Niitaka' and occurred earlier in trees growing at higher latitudes than at lower latitudes (warmer regions). The freezing tolerance of flower buds, measured as the lethal temperature for 50% survival (LT50), was similar for the cultivars beginning in autumn and reached maximum levels, LT50 values of less than -12 °C, between late-December and mid-January in both cultivars, except for those in Kagoshima (the lowest latitude), where the maximum LT50 was only -5 °C throughout the season. We propose that warmer autumn-winter temperatures may prevent the acquisition of freezing tolerance, disturb endodormancy progression and disrupt floral organ development, thereby causing flowering disorder in pear trees. The risk of occurrence of flowering disorder in pear may be higher in high-chill cultivars than in low- or mid-chill cultivars and at lower latitudes compared with higher latitudes.

Case report: Electron microscopic evaluation of bone from a patient treated with cinacalcet hydrochloride, maxacalcitol, and alfacalcidol for hyperparathyroid bone disease with secondary hyperparathyroidism

Evaluation of bone is of great importance in chronic kidney disease patients, as these patients are at an increased risk for fractures. We treated a hemodialysis patient suffering from hyperparathyroid bone disease with cinacalcet hydrochloride and concurrent administration of maxacalcitol and alfacalcidol for a year. Hyperparathyroid bone disease is characterized by cortical thinning, increased cortical porosity, reduced trabecular bone volume, and increased hypomineralized matrix volume, and there is little information to date about the effects of treatment with cinacalcet hydrochloride on the bone fragility in patients with hyperparathyroid bone disease. In the present study, histological and backscattered electron microscopic evaluation of this combination treatment revealed an excellent improvement of both bone volume and bone morphology. This treatment improved cortical thinning, cortical porosity, and trabecular thinning. Furthermore, the treatment also reduced hypomineralized matrix volume, indicative of improved mineralization by osteocytes. We speculate that the intermittent maxacalcitol administration may have effectively stimulated the vitamin D receptors expressed on osteocytes and osteoblasts, resulting in increased mineralization. Our approach for evaluating the bone in patients with chronic kidney disease by backscattered electron microscopy is novel.

Ethanol ablation for refractory bile leakage after complex hepatectomy

BACKGROUND

Only a few reports exist on the use of ethanol ablation for posthepatectomy bile leakage. The aim of this study was to assess the value of ethanol ablation in refractory bile leakage.

METHODS

Medical records of consecutive patients who underwent a first hepatobiliary resection with bilioenteric anastomosis between 2007 and 2016 were reviewed retrospectively, with special attention to bile leakage and ethanol ablation therapy. Bile leakage was graded as A/B1/B2 according to the International Study Group of Liver Surgery definition. Absolute ethanol was injected into the target bile duct during fistulography.

RESULTS

Of the 609 study patients, 237 (38·9 per cent) had bile leakage, including grade A in 33, grade B1 in 18 and grade B2 in 186. Left trisectionectomy was more often associated with grade B2 bile leakage than other types of hepatectomy (P < 0·001). Of 186 patients with grade B2 bile leakage, 31 underwent ethanol ablation therapy. Ethanol ablation was started a median of 34 (range 15-122) days after hepatectomy. The median number of treatments was 3 (1-7), and the total amount of ethanol used was 15 (3-71) ml. Complications related to ethanol ablation included transient fever (27 patients) and mild pain (13). Following ethanol ablation, bile leakage resolved in all patients and drains were removed. The median interval between the first ablation and drain removal was 28 (1-154) days.

CONCLUSION

Ethanol ablation is safe and effective, and may be a treatment option for refractory bile leakage.

Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are considered as one of the most important zoonotic diseases in Romania, where they are subject to mandatory reporting. To obtain more knowledge about the genetic diversity of Echinococcus causative agents of these diseases, 11 isolates from humans and ungulate intermediate hosts from the two regions of Romania were genotyped using mitochondrial markers. In clinical samples of five patients from north-eastern Romania (Iasi, Botosani, Vaslui counties), Echinococcus multilocularis was identified as causal agent by cox1 sequence analysis. To the best of our knowledge this finding presents the first molecular evidence of E. multilocularis in humans from Romania. Only two cases of AE in patients were previously documented in the country by serological methods. In our four patients the most widespread European variant E5 of E. multilocularis was recorded, whereas in isolate from Vaslui county three nucleotide substitutions were detected as compared to the most related E5 haplotype. One of these mutations (411T/G) matched N1 and N2 haplotypes described previously from North America. In six CE samples retrieved from western Romania (Caras-Severin and Timis counties), two human isolates were diagnosed as Echinococcus canadensis G7, one as E. granulosus s.s. G1 and one as E. granulosus s.s. G3 using atp6 and rrnS sequencing. In ungulates, the cattle isolate was allocated to E. granulosus s.s. G1 and pig isolate to E. canadensis G7. The two G7 findings in humans reinforced the recent view that G7 was underestimated as compared to the E. granulosus s.s. regarding human CE threat that can be further employed for identifying sources of infections and establishing suitable preventive measures.

Uncertainty in the response of terrestrial carbon sink to environmental drivers undermines carbon-climate feedback predictions

Terrestrial ecosystems play a vital role in regulating the accumulation of carbon (C) in the atmosphere. Understanding the factors controlling land C uptake is critical for reducing uncertainties in projections of future climate. The relative importance of changing climate, rising atmospheric CO2, and other factors, however, remains unclear despite decades of research. Here, we use an ensemble of land models to show that models disagree on the primary driver of cumulative C uptake for 85% of vegetated land area. Disagreement is largest in model sensitivity to rising atmospheric CO2 which shows almost twice the variability in cumulative land uptake since 1901 (1 s.d. of 212.8 PgC vs. 138.5 PgC, respectively). We find that variability in CO2 and temperature sensitivity is attributable, in part, to their compensatory effects on C uptake, whereby comparable estimates of C uptake can arise by invoking different sensitivities to key environmental conditions. Conversely, divergent estimates of C uptake can occur despite being based on the same environmental sensitivities. Together, these findings imply an important limitation to the predictability of C cycling and climate under unprecedented environmental conditions. We suggest that the carbon modeling community prioritize a probabilistic multi-model approach to generate more robust C cycle projections.

Physiological exercise loading suppresses post-traumatic osteoarthritis progression via an increase in bone morphogenetic proteins expression in an experimental rat knee model

OBJECTIVE

To evaluate the dose-response relationship of exercise loading in the cartilage-subchondral bone (SB) unit in surgically-induced post-traumatic osteoarthritis (PTOA) of the knee.

DESIGN

Destabilized medial meniscus (DMM) surgery was performed on the right knee of 12-week-old male Wistar rats, and sham surgery was performed on the contralateral knee. Four weeks after the surgery, the animals were subjected to moderate (12 m/min) or intense (21 m/min) treadmill exercises for 30 min/day, 5 days/week for 4 weeks. PTOA development in articular cartilage and SB was examined using histological and immunohistochemical analyses, micro-computed tomography (micro-CT) analysis, and biomechanical testing at 8 weeks after surgery. Gremlin-1 was injected to determine the role of bone morphogenetic protein (BMP) signaling on PTOA development following moderate exercise.

RESULTS

Moderate exercise increased BMP-2, BMP-4, BMP-6, BMP receptor 2, pSmad-5, and inhibitor of DNA binding protein-1 expression in the superficial zone chondrocytes and suppressed cartilage degeneration, osteophyte growth, SB damage, and osteoclast-mediated SB resorption. However, intense exercise had little effect on BMP expression and even caused progression of these osteoarthritis (OA) changes. Gremlin-1 injection following moderate exercise caused progression of the PTOA development down to the level of the non-exercise DMM-operated knee.

CONCLUSIONS

Exercise regulated cartilage-SB PTOA development in DMM-operated knees in a dose-dependent manner. Our findings shed light on the important role of BMP expression in superficial zone chondrocytes in attenuation of PTOA development following physiological exercise loading. Further studies to support a mechanism by which BMPs would be beneficial in preventing PTOA progression are warranted.

Gastrointestinal helminths and Taenia spp. in parenteral tissues of free-roaming pigs (Sus scrofa indicus) from hilltribe village at the western border of Thailand

A serological survey of pig cysticercosis was conducted in a hill-tribe village at Thai-Myanmar border, Tak province of Thailand in 2012. Sixteen backyard pigs were examined for pig cysticercosis and gastrointestinal helminth infection. In addition to cysticerci of Taenia solium and Taenia hydatigena found outside the gut, nine other helminth species were found in guts: Echinostoma malayanum, Pseudanoplocephala crawfordi, Ascarops dentata, Physocephalus sexalatus, Gnathostoma doloresi, Ascaris suum, Globocephalus sp., Oesophagostomum dentatum and Bourgelatia diducta. The study presents a report for the first time of adult tapeworm, P. crawfordi infection in pigs from Thailand. For medical importance, E. malayanum, P. crawfordi, G. doloresi and A. suum have been confirmed as potentially zoonotic helminths and pigs may act as one of the reservoir hosts for human helminthiases. Pigs of both gender and all ages appeared to be exposed to the parasites equally and did not show any significant difference to these helminth species in richness and total intensity.

Accelerated anaerobic release of K, Mg and P from surplus activated sludge for element recovery and struvite formation inhibition

Accelerated release of potassium (K), magnesium (Mg) and phosphorus (P) from surplus activated sludge (SAS) was investigated to develop a new system for the recovery of the elements. Anaerobic cultivation of SAS during 24 h released 78% of K and about 50% of Mg and P from SAS more effectively compared to aerobic cultivation (K: 40%, Mg: 15%, P: 15%). Furthermore, the addition of sodium acetate as an organic carbon source remarkably accelerated the release of K, Mg and P from SAS under anaerobic condition. However, no increase in the maximum release efficiencies was observed. The elements released from SAS could be transferred to separate liquid with the existing mechanical thickener and be recovered as MgKPO₄ by some additional process. Furthermore, the removal of the elements from SAS would inhibit the formation of struvite causing the blockage of sludge transport pipe after anaerobic digestion process of thickened sludge.