Pt-doped Ru nanoparticles loaded on 'black gold' plasmonic nanoreactors as air stable reduction catalysts.

This study introduces a plasmonic reduction catalyst, stable only in the presence of air, achieved by integrating Pt-doped Ru nanoparticles on black gold. This innovative black gold/RuPt catalyst showcases good efficiency in acetylene semi-hydrogenation, attaining over 90% selectivity with an ethene production rate of 320 mmol g-1 h-1. Its stability, evident in 100 h of operation with continuous air flow, is attributed to the synergy of co-existing metal oxide and metal phases. The catalyst's stability is further enhanced by plasmon-mediated concurrent reduction and oxidation of the active sites. Finite-difference time-domain simulations reveal a five-fold electric field intensification near the RuPt nanoparticles, crucial for activating acetylene and hydrogen. Kinetic isotope effect analysis indicates the contribution from the plasmonic non-thermal effects along with the photothermal. Spectroscopic and in-situ Fourier transform infrared studies, combined with quantum chemical calculations, elucidate the molecular reaction mechanism, emphasizing the cooperative interaction between Ru and Pt in optimizing ethene production and selectivity.

Atomically precise Au and Ag nanoclusters doped with a single atom as model alloy catalysts.

Gold and silver nanoclusters (NCs) composed of <200 atoms are novel catalysts because their catalytic properties differ significantly from those of the corresponding bulk surface and can be dramatically tuned by the size (number of atoms). Doping with other metals is a promising approach for improving the catalytic performance of Au and Ag NCs. However, elucidation of the origin of the doping effects and optimization of the catalytic performance are hampered by the technical challenge of controlling the number and location of the dopants. In this regard, atomically precise Au or Ag (Au/Ag) NCs protected by ligands or polymers have recently emerged as an ideal platform because they allow regioselective substitution of single Au/Ag constituent atoms while retaining the size and morphology of the NC. Heterogeneous Au/Ag NC catalysts doped with a single atom can also be prepared by controlled calcination of ligand-protected NCs on solid supports. Comparison of thermal catalysis, electrocatalysis, and photocatalysis between the single-atom-doped and undoped Au/Ag NCs has revealed that the single-atom doping effect can be attributed to an electronic or geometric origin, depending on the dopant element and position. This minireview summarizes the recent progress of the synthesis and catalytic application of single-atom-doped, atomically precise Au/Ag NC catalysts and provides future prospects for the rational development of active and selective metal NC catalysts.

Synergistically Activated Pd Atom in Polymer-Stabilized Au23Pd1 Cluster.

Single Pd atom doped Au23Pd1 clusters stabilized by polyvinylpyrrolidone (Au23Pd1:PVP) were selectively synthesized by kinetically controlled coreduction of the Au and Pd precursor ions. The geometric structure of Au23Pd1:PVP was investigated by density functional theory calculation, aberration-corrected transmission electron microscopy, extended X-ray absorption fine structure analysis, Fourier transform infrared spectroscopy of adsorbed CO, and hydrogenation catalysis. These results showed that Au23Pd1:PVP takes polydisperse but the same atomic arrangements as undoped Au24:PVP while exposing all the atoms including the Pd atom on the surface. Au23Pd1:PVP exhibited a significantly higher catalytic activity than Au24:PVP for the aerobic oxidation of p-substituted benzyl alcohols. The kinetic studies showed that the rate-determining step was the hydride abstraction from the α-carbon of the alkoxides for both systems. The activation energy for hydride abstraction by Au23Pd1:PVP was lower than that by Au24:PVP, indicating that the doped Pd atom acts as the active center.

Revealing hydrogen spillover pathways in reducible metal oxides.

Hydrogen spillover, the migration of dissociated hydrogen atoms from noble metals to their support materials, is a ubiquitous phenomenon and is widely utilized in heterogeneous catalysis and hydrogen storage materials. However, in-depth understanding of the migration of spilled hydrogen over different types of supports is still lacking. Herein, hydrogen spillover in typical reducible metal oxides, such as TiO2, CeO2, and WO3, was elucidated by combining systematic characterization methods involving various in situ techniques, kinetic analysis, and density functional theory calculations. TiO2 and CeO2 were proven to be promising platforms for the synthesis of non-equilibrium RuNi binary solid solution alloy nanoparticles displaying a synergistic promotional effect in the hydrolysis of ammonia borane. Such behaviour was driven by the simultaneous reduction of both metal cations under a H2 atmosphere over TiO2 and CeO2, in which hydrogen spillover favorably occurred over their surfaces rather than within their bulk phases. Conversely, hydrogen atoms were found to preferentially migrate within the bulk prior to the surface over WO3. Thus, the reductions of both metal cations occurred individually on WO3, which resulted in the formation of segregated NPs with no activity enhancement.

The endothelial Dll4-muscular Notch2 axis regulates skeletal muscle mass.

Adult skeletal muscle is a highly plastic tissue that readily reduces or gains its mass in response to mechanical and metabolic stimulation; however, the upstream mechanisms that control muscle mass remain unclear. Notch signalling is highly conserved, and regulates many cellular events, including proliferation and differentiation of various types of tissue stem cell via cell-cell contact. Here we reveal that multinucleated myofibres express Notch2, which plays a crucial role in disuse- or diabetes-induced muscle atrophy. Mechanistically, in both atrophic conditions, the microvascular endothelium upregulates and releases the Notch ligand, Dll4, which then activates muscular Notch2 without direct cell-cell contact. Inhibition of the Dll4-Notch2 axis substantively prevents these muscle atrophy and promotes mechanical overloading-induced muscle hypertrophy in mice. Our results illuminate a tissue-specific function of the endothelium in controlling tissue plasticity and highlight the endothelial Dll4-muscular Notch2 axis as a central upstream mechanism that regulates catabolic signals from mechanical and metabolic stimulation, providing a therapeutic target for muscle-wasting diseases.

Synthesis of active, robust and cationic Au25 cluster catalysts on double metal hydroxide by long-term oxidative aging of Au25(SR)18.

Synthesis of an atomically precise Au25 cluster catalyst was attempted by long-term, low-temperature aging of Au25(BaET)18 (BaET-H = 2-(Boc-amino)ethanethiol) on various double metal hydroxide (DMH) supports. X-ray absorption fine structure analysis revealed that bare Au25 clusters with high loading (1 wt%) were successfully generated on the DMH containing Co and Ce (Co3Ce) by oxidative aging in air at 150 °C for >12 h. X-ray absorption near-edge structure and X-ray photoelectron spectroscopies showed that the Au25 clusters on Co3Ce were positively charged. The Au25/Co3Ce catalyst thus synthesized exhibited superior catalytic performance in the aerobic oxidation of benzyl alcohol under ambient conditions (TOF = 1097 h-1 with >97% selectivity to benzoic acid) and high durability owing to a strong anchoring effect. Based on kinetic experiments, we propose that abstraction of hydride from α-carbon of benzyl alkoxide by Au25 is the rate-determining step of benzyl alcohol oxidation by Au25/Co3Ce.

Edible bird's nest extract downregulates epidermal apoptosis and helps reduce damage by ultraviolet radiation in skin of hairless mice.

The purpose of the present study was to examine whether daily intake of edible bird's nest extract reduced ultraviolet-induced damage to skin. Twenty-one female HR-1/Hos mice were divided into control (C, n = 7), low-dose (2 mg/kg body weight/day of edible bird's nest extract) (L, n = 7), and high-dose (20 mg/kg body weight/day of edible bird's nest extract) (H, n = 7) groups. With their left back skin covered with aluminum sheet to prevent exposure, mice were radiated with either ultraviolet A (20 J/cm2) or ultraviolet B (40 mJ/cm2) in an alternate manner once daily for 10 weeks. They were gavaged either a solution of saline or edible bird's nest extract every day. The moisture content of the ultraviolet-exposed right back skin was significantly higher in H than in C or L. Histochemical analysis showed that the number of apoptotic epidermal cells on the ultraviolet-exposed skin was significantly lower in L and H than in C. In H, the mRNA expression of superoxide dismutase 2 was significantly higher on ultraviolet-exposed skin than on unexposed skin. Our data suggested that edible bird's nest extract enhanced superoxide dismutase 2 expression and downregulated apoptosis in their epidermis, which likely helped reduce skin damage.

Efficacy of Preoperative Bilateral Thoracic Paravertebral Block in Cardiac Surgery Requiring Full Heparinization: A Propensity-Matched Study.

OBJECTIVES: To assess the efficacy of preoperative bilateral paravertebral block (PVB) with general anesthesia (GA) in contributing to early extubation and decreasing opioid consumption in cardiac surgery. DESIGN: A propensity score-matched retrospective study. SETTING: A single tertiary medical center between January 2018 and December 2020. PARTICIPANTS: Adult patients undergoing isolated first-time aortic valve replacement and coronary artery bypass grafting with full sternotomy. INTERVENTIONS: A cohort of 44 patients who received PVB with GA (PVB group) was matched with 44 patients who underwent similar surgery with GA only (GA only group). MEASUREMENTS AND MAIN RESULTS: The completion rate of extubation in the operating room was significantly greater in the PVB group (65.9%) than in the GA only group (43.2%; p = 0.032). The completion rate of extubation within eight hours after surgery also was significantly greater in the PVB group (86.4%) than in the GA only group (68.2%; p = 0.042). The median amount of intraoperative fentanyl administered was significantly less in the PVB group (4.8 µg/kg; interquartile range [IQR], 3.3-7.2) than in the GA only group (8.4 µg/kg; IQR, 5.4-12.7; p < 0.001). The median amount of postoperative fentanyl administered was significantly less in the PVB group (6.8 µg/kg; IQR, 3.9-10.6) than in the GA only group (8.1 µg/kg; IQR, 6.2-15.9; p = 0.012). CONCLUSIONS: This study demonstrated that preoperative bilateral PVB combined with GA contributed to early extubation in isolated first-time aortic valve replacement and coronary artery bypass grafting and in the reduction of intraoperative and postoperative fentanyl consumption.

Effect of malnutrition and frailty status on surgical aortic valve replacement.

OBJECTIVES: To date, assessment of nutritional and frailty status in patients undergoing surgical aortic valve replacement remains unclear. This study aimed to assess the effect of geriatric nutritional risk index (GNRI) and Rockwood clinical frailty scale (CFS) on short-term and mid-term survival in patients who underwent surgical aortic valve replacement for aortic stenosis. METHODS: In total, 219 patients who underwent aortic valve replacement for aortic stenosis between Jan 1 2011 and Dec 31 2018 were retrospectively monitored in a single center. Mid-term survival was assessed using Kaplan-Meier analysis. Logistic and Cox regression analyses were performed to detect independent predictors for early and mid-term mortality. Follow-up was 97.7% complete, and a GNRI score ≤ 98 denoted malnutrition. RESULTS: In the univariable analysis, GNRI [odds ratio (OR) 0.91, 95% confidence interval (CI), 0.86-0.96, p < 0.001] and CFS (OR 2.00 95% CI 1.38-2.94, p < 0.001) were identified as significant risk factors for in-hospital mortality. Mid-term survival was significantly decreased in patients with malnutrition (3 and 5 year survival rates 83.9 and 76.9%, respectively, p < 0.001). Mid-term freedom from major cardiac and cerebrovascular events was significantly decreased in patients with malnutrition (p = 0.039). The CFS (hazard ratio 1.78) and GNRI (hazard ratio 0.95) were independent risk factors for mid-term survival in the univariable and multivariable analyses, respectively. CONCLUSIONS: A lower GNRI is associated with poor mid-term mortality and major cardiac and cerebrovascular events after surgical aortic valve replacement. A lower CFS score is associated with unfavorable mid-term outcomes.

Decorating an anisotropic Au13 core with dendron thiolates: enhancement of optical absorption and photoluminescence.

We successfully introduced up to 12 poly(benzyl ether)dendron-thiols of the second generation (D2SH) into the Au13 core of [Au23(ScC6H11)16]- while retaining the geometric structure. The decoration with D2SH enhanced the optical absorbance in the >2.5 eV region and the quantum yield of photoluminescence at ∼1.6 eV by ∼15 times.

Successful ligation of posterior tibial vein aneurysm performed according to intraoperative venography results.

A 23-year-old woman was diagnosed with a posterior tibial vein aneurysm that had resulted in deep vein thrombosis and a pulmonary embolism. The patient responded well to anticoagulation therapy, and surgical resection was planned to prevent recurrence. She was scheduled to undergo tangential aneurysmectomy and lateral venorrhaphy. However, the aneurysm could not be completely exposed because of adhesions. Therefore, venography was performed to identify the inflow and outflow vessels, which were ligated because an accessory venous communication was identified. Intraoperative venography can aid in the selection of simple ligation or reconstruction of a venous communication for the treatment of posterior tibial vein aneurysms.

Few-nm-sized, phase-pure Au5Sn intermetallic nanoparticles: synthesis and characterization.

Nanoparticles of intermetallic compounds have attracted much interest because they can exhibit novel electronic and catalytic properties due to their specific crystal structure, ordered atomic arrangement, and quantum effect. Here, gold-tin (AuSn) bimetallic nanoparticles with various mixing ratios were prepared by a co-reduction method using various protective agents (e.g., polymer, amine, phosphine, carboxylic acid, and thiol). Powder X-ray diffractometry and transmission electron microscopy revealed that few-nm-sized, phase-pure Au5Sn intermetallic nanoparticles (IMNPs) were successfully synthesized when Au3+ and Sn2+ precursors with a ratio of 6 : 4 were co-reduced in the presence of oleylamine. The Au5Sn IMNPs thus prepared did not exhibit localized surface plasmon resonance, in contrast to pure Au nanoparticles of comparable sizes. This suggests that interband transition dominates the optical response due to an increase in the density of states near the Fermi level by introducing Sn. The Au5Sn IMNPs supported on mesoporous silica (SBA-15) catalyzed the aerobic oxidation reaction of indanol.

Intimal sarcoma of the pulmonary artery without 18F-fluorodeoxyglucose uptake.

Primary pulmonary intimal sarcoma is rare. Differentiating it from pulmonary thromboembolism is difficult because of similarities in clinical symptoms and imaging findings. Positron-emission tomography-computed tomography has been useful for diagnosing primary pulmonary intimal sarcoma. We describe a rare case of primary pulmonary intimal sarcoma that showed no abnormal 18F-fluorodeoxyglucose uptake on positron-emission tomography. We resected the mass and performed right ventricular outflow tract reconstruction. Proper diagnosis is necessary to determine appropriate therapy, Clinicians must consider the possibility of primary pulmonary intimal sarcoma even if imaging findings are inconsistent with the disease.

Synthesis of a binary alloy nanoparticle catalyst with an immiscible combination of Rh and Cu assisted by hydrogen spillover on a TiO2 support.

This work demonstrated the use of TiO2 as a promising platform for the synthesis of non-equilibrium RhCu binary alloy nanoparticles (NPs). These metals are regarded as immiscible based on their phase diagram but form NPs with the aid of the significant hydrogen spillover on TiO2 with concurrent proton-electron transfer. The resulting RhCu/TiO2 exhibited 2.6 times higher catalytic activity than Rh/TiO2 during hydrogen production from the hydrolysis of ammonia borane (AB), due to a synergistic effect. Theoretical simulations showed a higher energy value for the adsorption of AB on the RhCu alloy and a lower activation energy for the rate determining N-B bond dissociation by the attack of H2O during AB hydrolysis compared to monometallic Rh. High-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy confirmed the formation of RhCu alloy NPs with a mean diameter of 2.0 nm on the TiO2. H2-temperature programmed reduction and in situ X-ray absorption fine structure analyses at elevated temperature under H2 demonstrated that Rh3+ and Cu2+ precursors were simultaneously reduced only on the TiO2 support. This effect resulted from the improved and limited reducibility of Cu2+ and Rh3+, respectively. The rate of hydrogen spillover of TiO2 is faster as compared to γ-Al2O3 and MgO as evidenced by sequential H2/D2 exchanges during in situ Fourier transform infrared analyses. Density functional theory calculations also showed that the migration of H atoms on TiO2 proceeds with a lower energy barrier than that on Al2O3, and the reduction of Cu2+ species is facilitated by H spillover on the support rather than by direct reduction by H2. These results confirm the vital role of TiO2 in the formation of the alloy and may represent a new strategy for the synthesis of different non-equilibrium solid solution alloys.

Compression of the Left Atrium and Left Ventricle by a Thoracoabdominal Aortic Aneurysm: A Case Report.

We describe the case of a 66-year-old man with a thoracoabdominal aortic aneurysm, who presented with cardiac failure; he had complained of shortness of breath. A contrast-enhanced computed tomography scan and transthoracic echocardiography showed compression of the left atrium and ventricle by a giant thoracoabdominal aortic aneurysm. The cardiac failure resolved after early prosthetic graft replacement surgery.

Controlled release of hydrogen isotope compounds and tunneling effect in the heterogeneously-catalyzed formic acid dehydrogenation.

The hydrogen isotope deuterium is widely used in the synthesis of isotopically-labeled compounds and in the fabrication of semiconductors and optical fibers. However, the facile production of deuterium gas (D2) and hydrogen deuteride (HD) in a controlled manner is a challenging task, and rational heterogeneously-catalyzed protocols are still lacking. Herein, we demonstrate the selective production of hydrogen isotope compounds from a combination of formic acid and D2O, through cooperative action by a PdAg nanocatalyst on a silica substrate whose surface is modified with amine groups. In this process, D2 is predominantly evolved by the assist of weakly basic amine moieties, while nanocatalyst particles in the vicinity of strongly basic amine groups promote the preferential formation of HD. Kinetic data and calculations based on semi-classically corrected transition state theory coupled with density functional theory suggest that quantum tunneling dominates the hydrogen/deuterium exchange reaction over the metallic PdAg surfaces.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure.

OBJECTIVES: Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution. METHODS: The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties. RESULTS: The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05). CONCLUSIONS: Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

Role of serum myostatin in the association between hyperinsulinemia and muscle atrophy in Japanese obese patients.

AIMS: The protein myostatin is a member of the transforming growth factor ß superfamily. This is mainly expressed in skeletal muscle and negatively regulates skeletal muscle growth. The present study aimed to elucidate the associations among circulating myostatin level, skeletal muscle mass, and metabolic profiles in Japanese obese patients. METHODS: Japanese obese outpatients (n = 74) were enrolled. We measured clinical parameters, quantified serum myostatin levels, and examined their associations in a cross-sectional manner. RESULTS: Both total skeletal muscle mass and serum myostatin level were higher in males than in females. Among 74 patients, serum myostatin level was positively correlated with skeletal muscle mass and serum immunoreactive insulin (IRI) level [correlation coefficient (r) = 0.294, P = 0.011; r = 0.262, P = 0.024, respectively]. Furthermore, multivariate linear regression analysis revealed that serum myostatin level was positively correlated with IRI after adjusting for gender and skeletal muscle mass (ß-coefficient = 0.230, P = 0.029, R2 = 0.236). CONCLUSIONS: In obese patients, serum myostatin level was elevated in conjunction with an increase in IRI level independent of skeletal muscle mass. This may imply possible novel pathological implications of serum myostatin in muscle mass and metabolism in obese patients with hyperinsulinemia.