Effect of Heat Treatment on Structure of Carbon Shell-Encapsulated Pt Nanoparticles for Fuel Cells.

Polymer electrolyte membrane fuel cells (PEMFCs) have attracted much attention as highly efficient, eco-friendly energy conversion devices. However, carbon-supported Pt (Pt/C) catalysts for PEMFCs still have several problems, such as low long-term stability, to be widely commercialized in fuel cell applications. To address the stability issues of Pt/C such as the dissolution, detachment, and agglomeration of Pt nanoparticles under harsh operating conditions, we design an interesting fabrication process to produce a highly active and durable Pt catalyst by introducing a robust carbon shell on the Pt surface. Furthermore, this approach provides insights into how to regulate the carbon shell layer for fuel cell applications. Through the application of an appropriate amount of H2 gas during heat treatment, the carbon shell pores, which are integral to the structure, can be systematically modulated to facilitate oxygen adsorption for the oxygen reduction reaction. Simultaneously, the carbon shell functions as a protective barrier, preventing catalyst degradation. In this regard, we investigate an in-depth analysis of the effects of critical parameters including H2 content and the flow rate of H2/N2 mixed gas during heat treatment to prepare better catalysts.

Myelomatous pleural effusion in multiple myeloma- A rare presentation.

Multiple myeloma is a malignant plasma cell condition that mostly affects the skeletal system and bone marrow. Pleural effusions are uncommon and typically result from other conditions coexisting with multiple myeloma. Malignant myelomatous pleural effusions are rare complications of multiple myeloma, occurring in less than 1% of patients and are associated with poor prognosis having mean survival of less than 4 months. The present case report is a 41-year-old multiple myeloma patient who developed bilateral pleural effusion at a disease relapse. Chemotherapeutic regimen of cyclophosphamide, bortezomib, and dexamethasone given. Despite a positive response to treatment, the patient's condition worsened over the course of following month and he eventually passed away. Myelomatous pleural effusion indicates poor prognosis and early consideration helps in quick diagnosis and initiation of treatment which may help in improving prognosis.

Origin and Formation Mechanism of Carbon Shell-Encapsulated Metal Nanoparticles for Powerful Fuel Cell Durability.

Proton exchange membrane fuel cells (PEMFCs) face technical issues of performance degradation due to catalyst dissolution and agglomeration in real-world operations. To address these challenges, intensive research has been recently conducted to introduce additional structural units on the catalyst surface. Among various concepts for surface modification, carbon shell encapsulation is known to be a promising strategy since the carbon shell can act as a protective layer for metal nanoparticles. As an interesting approach to form carbon shells on catalyst surfaces, the precursor ligand-induced formation is preferred due to its facile synthesis and tunable control over the carbon shell porosity. However, the origin of the carbon source and the carbon shell formation mechanism have not been studied in depth yet. Herein, this study aims to investigate carbon sources through the use of different precursors and the introduction of new methodologies related to the ligand exchange phenomenon. Subsequently, we provide new insights into the carbon shell formation mechanism using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Finally, the thermal stability and electrochemical durability of carbon shells are thoroughly investigated through in situ transmission electron microscopy (in situ TEM) and accelerated durability tests.

Outcomes of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Non-ST-Elevation Myocardial Infarction-Propensity Matched Regression Analysis.

Intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI) is indicated in complex interventions. There is a paucity of evidence for outcomes with large studies on using IVUS during PCI in non-ST-elevation myocardial infarction (NSTEMI). Our objective was to compare the in-hospital outcome of IVUS-guided with that of nonguided PCI among NSTEMI hospitalizations. The National Inpatient Sample (2016 to 2019) was queried to identify all hospitalizations with a principal diagnosis of NSTEMI. In our study, we compared outcomes of PCI with and without IVUS guidance using a multivariate logistic regression model after propensity score matching, with the primary outcome being in-hospital mortality. A total of 671,280 NSTEMI-related hospitalizations were identified, of whom 48,285 (7.2%) underwent IVUS-guided PCI compared with 622,995 (92.8%) who underwent non-IVUS PCI. After adjusted analysis on matched pairs, we found that IVUS-guided PCI had a lower risk of in-hospital mortality than that of non-IVUS PCI (adjusted odds ratio [aOR] 0.736, confidence interval (CI) 0.578 to 0.937, p = 0.013). However, there was a higher use of mechanical circulatory support in the IVUS-guided PCI (aOR 2.138, CI 1.84 to 2.47, p <0.001) than in non-IVUS PCI. The odds of cardiogenic shock (aOR 1.11, CI 0.93 to 1.32, p = 0.233) and procedural complications (aOR 0.794, CI 0.549 to 1.14, p = 0.22) were similar between the cohorts. Hence, we conclude that patients with NSTEMIs who underwent IVUS-guided PCI had less risk of in-hospital mortality and a greater requirement of mechanical circulatory support than did those who underwent non-IVUS PCI, with no difference in procedural complications. Large prospective trials are essential to validate these findings.

Measure cross-sectoral structural similarities from financial networks.

Auditing is a multi-billion dollar market, with auditors assessing the trustworthiness of financial data, contributing to financial stability in a more interconnected and faster-changing world. We measure cross-sectoral structural similarities between firms using microscopic real-world transaction data. We derive network representations of companies from their transaction datasets, and we compute an embedding vector for each network. Our approach is based on the analysis of 300+ real transaction datasets that provide auditors with relevant insights. We detect significant changes in bookkeeping structure and the similarity between clients. For various tasks, we obtain good classification accuracy. Moreover, closely related companies are near in the embedding space while different industries are further apart suggesting that the measure captures relevant aspects. Besides the direct applications in computational audit, we expect this approach to be of use at multiple scales, from firms to countries, potentially elucidating structural risks at a broader scale.

Fine-tuning of ultrathin carbon shells coated on metal nanoparticles: carbon etching and defect healing effects.

Carbon-incorporated metal nanoparticles are heat-treated in various gas atmospheres to create carbon shells with different porosity. A highly porous carbon shell is formed due to the carbon etching effect by H2, and the defect healing effect by CO is discovered through additional CO gas treatment of the H2/N2 gas-treated sample.

Activity Quantification of Fuel Cell Catalysts via Sequential Poisoning by Multiple Reaction Inhibitors.

The development of non-Pt or carbon-based catalysts for anion exchange membrane fuel cells (AEMFCs) requires identification of the active sites of the catalyst. Since not only metals but also carbon materials exhibit oxygen reduction reaction (ORR) activity in alkaline conditions, the contribution of carbon-based materials to ORR performance should also be thoroughly analyzed. However, the conventional CN- poisoning experiments, which are mainly used to explain the main active site of M-N-C catalysts, are limited to only qualitative discussions, having the potential to make fundamental errors. Here, we report a modified electrochemical analysis to quantitatively investigate the contribution of the metal and carbon active sites to ORR currents at a fixed potential by sequentially performing chronoamperometry with two reaction inhibitors, CN- and benzyl trimethylammonium (BTMA+). As a result, we discover how to quantify the individual contributions of two active sites (Pt nanoparticles and carbon support) of carbon-supported Pt (Pt/C) nanoparticles as a model catalyst. This study is expected to provide important clues for the active site analysis of carbon-supported non-Pt catalysts, such as M-N-C catalysts composed of heterogeneous elements.

A Systematic Review of the Sensory Outcomes of a Standard Cross-Finger Flap Reconstruction for Fingertip Defects.

Background: The standard (dorsal) cross-finger flap (CFF) is one of the common flaps used for fingertip reconstruction. There is little consensus regarding the sensory outcomes associated with this flap. In this systematic review, we evaluated objective sensory outcome parameters of patients who underwent CFF reconstruction. Methods: This systematic review is reported using the PRISMA protocol and was registered with the International Prospective Register of Systematic Reviews. Literature search was done using the terms 'cross-finger flap', 'heterodigital', 'finger-tip' and 'transdigital'. Data regarding the number of patients, follow-up duration and sensory outcomes, including 2-point discrimination (2-PD) were extracted from included studies. The analysis was performed using Microsoft Excel with MetaXL add-in software. Certainty assessment and summary of findings table was created using GRADEpro GDT. Results: This review includes 14 studies with 301 patients. We found a statistically significant difference in static 2-PD of recipient and control fingers (pooled weighted mean difference [WMD]: 1.66; 95%CI: 0.03, 3.29; p = 0.00; I2=92%, n = 7 studies). Conclusions: Dorsal CFF reconstruction for fingertip defect does not provide adequate sensory recovery. Level of Evidence: Level III (Therapeutic).

Consistent evaluation of continuum scale properties of two-dimensional materials: a case study on graphene.

We handshake statistical mechanics with continuum mechanics to develop a methodology for consistent evaluation of the continuum scale properties of two-dimensional materials. The methodology is tested on pristine graphene. Our scope is kept limited to elastic modulus, E, which has been reported to vary between 0.912 TPa and 7 TPa, Poisson's ratio, ν, which has been reported to vary from being negative to a value as large as 0.46, and effective thickness, q, whose value varies between 0.75 Å and 3.41 Å. Such a large scatter arises due to inconsistent evaluation of these properties and making assumptions that may not be valid at atomistic scales. Our methodology combines three separate methods: uniaxial tension, equibiaxial tension, and flexural out-of-plane free vibrations of simply supported sheets, which, when used in tandem in molecular dynamics, can provide consistent values of E, ν and q. The only assumption made in the present study is the validity of the continuum scale thin plate vibration equation to represent the free vibrations of a graphene sheet. Our results suggest that-(i) graphene is auxetic in nature, (ii) E decreases with increasing size and temperature, and (iii) the effective thickness q increases with increasing size and temperature. Further, a robustness study of the computed mechanical properties shows consistent results, with differences varying between 1.4% and 6%.

Reducing the complexity of financial networks using network embeddings.

Accounting scandals like Enron (2001) and Petrobas (2014) remind us that untrustworthy financial information has an adverse effect on the stability of the economy and can ultimately be a source of systemic risk. This financial information is derived from processes and their related monetary flows within a business. But as the flows are becoming larger and more complex, it becomes increasingly difficult to distill the primary processes for large amounts of transaction data. However, by extracting the primary processes we will be able to detect possible inconsistencies in the information efficiently. We use recent advances in network embedding techniques that have demonstrated promising results regarding node classification problems in domains like biology and sociology. We learned a useful continuous vector representation of the nodes in the network which can be used for the clustering task, such that the clusters represent the meaningful primary processes. The results show that we can extract the relevant primary processes which are similar to the created clusters by a financial expert. Moreover, we construct better predictive models using the flows from the extracted primary processes which can be used to detect inconsistencies. Our work will pave the way towards a more modern technology and data-driven financial audit discipline.

Understanding Transmission Dynamics of COVID-19-Type Infections by Direct Numerical Simulations of Cough/Sneeze Flows.

The transmission dynamics of highly contagious respiratory diseases like COVID-19 (through coughing/sneezing) is an open problem in the epidemiological studies of such diseases (Bourouiba, JAMA. https://doi.org/10.1001/jama.2020.4756. 2020). The problem is basically the fluid dynamics of a transient turbulent jet/puff with buoyancy, laden with evaporating droplets carrying the pathogen. A turbulent flow of this nature does not lend itself to reliable estimates through modeling approaches such as RANS (Reynolds-Averaged Navier-Stokes equations) or other droplet-based models. However, direct numerical simulations (DNS) of what may be called "cough/sneeze flows" can play an important role in understanding the spread of the contagion. The objective of this work is to develop a DNS code for studying cough/sneeze flows by a suitable combination of the DNS codes available with the authors (developed to study cumulus cloud flows including thermodynamics of phase change and the dynamics of small water droplets) and to generate useful data on these flows. Recent results from the cumulus cloud simulations are included to highlight the effect of turbulent entrainment (which is one of the key processes in determining the spread of the expiratory flows) on the distribution of liquid water content in a moist plume. Furthermore, preliminary results on the temperature distribution in a "dry cough" (i.e., without inclusion of liquid droplets) are reported to illustrate the large spatial extent and time duration over which the cough flow can persist after the coughing has stopped. We believe that simulations of this kind can help to devise more accurate guidelines for separation distances between neighbors in a group, design better masks, and minimize the spread of respiratory diseases of the COVID-19 type.

Favourable improvement in haematological parameters in response to oral iron and vitamin C combination in children with Iron Refractory Iron Deficiency Anemia (IRIDA) phenotype.

Treatment in IRIDA focuses on use of intravenous iron preparations to circumvent oral absorptive defect resulting from high levels of hepcidin due to TMPRSS6 gene variations. However, recent case reports and recommendations on atypical microcytic hypochromic anemias advocate use of oral iron and vitamin c trial before parenteral iron, as the same results in comparable improvement in haemoglobin. We prospectively evaluated our IRIDA cohort (n = 7) with oral iron and vitamin c dose over a period of 10 weeks and noted complete response in majority (6/7 = 86%) with >2 g/dL rise in Hb along with significant improvement of other iron related indices.

Phytoremediation of fluoride with garden ornamentals Nerium oleander, Portulaca oleracea, and Pogonatherum crinitum.

Nursery grown plants of Nerium oleander, Pogonatherum crinitum, and Portulaca oleracea were observed to remove fluoride up to 92, 80, and 73%, respectively, from NaF solution at the concentration of 10 mg L-1 within 15 days. Concentration range of 10-50 mg L-1 of fluoride revealed a constant decrease of removal from 92 to 51% within 15 days by N. oleander, while the biomass (one to five plants) showed enhancement in removal from 74 to 98% in 10 days. Translocation and bioaccumulation factors calculated after fluoride contents in roots and leaves of N. oleander, P. crinitum, and P. oleracea were 1.85, 1.19, and 1.43, and 9.8, 3.6, and 2.2, respectively. P . oleracea, P. crinitum, and N. oleander showed reductions in chlorophyll contents by 40, 57 and 25 and 8%, carbohydrates by 50, 44, and 16%, and proteins by 38, 53, and 15%, respectively. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in the roots of P. oleracea, P. crinitum, and N. oleander were observed to be induced by 400, 383, and 500%; 80, 105, and 424%; and 153, 77, and 71%, respectively, while the leaves showed induction in SOD, CAT, and GPX activities by 550, 315, and 165%; 196, 227, and 243%; and 280, 242, and 184%, respectively. Results endorsed the superiority of N. oleander for fluoride removal over other plant species.

Acute promyelocytic leukemia-associated Sweet's syndrome mimicking an axillary abscess: A case report with review of literature.

A subcutaneous painful left axillary nodule was clinically diagnosed as abscess. Fine-needle aspiration biopsy (FNAB) revealed smears full of mature neutrophils. Background was free of fibrinous necrotic material and degenerating and necrotic neutrophils, which is characteristic of abscess. No organisms were detectable on special staining, and culture was sterile. A cytological differential diagnosis of abscess or Sweet's syndrome (SS) was offered, and the latter was confirmed. SS, also known as acute febrile neutrophilic dermatosis, shows diffuse dermal neutrophilic infiltrate without vasculitis on biopsy. Our case is probably the first where SS was diagnosed on FNAB. SS is a differential diagnosis for painful skin nodules. FNAB smears of painful skin nodules that yield abundant neutrophils should be carefully evaluated for necrosis, fibrin and degenerated neutrophils. The absence of these in an appropriate clinical setting points towards a neutrophilic dermatosis like SS.

Prevalence of Deep Vein Thrombosis and Pulmonary Embolism Treated with Mechanical Compression Device After Total Knee Arthroplasty in Asian Patients.

The purpose of this study was: (1) to determine the prevalence of deep vein thrombosis (DVT) after the use of a mechanical compression device only, without pharmacological thromboprophylaxis; (2) to investigate the factors associated with DVT; and (3) to investigate the natural course of DVT and PE. We reviewed consecutive series of 874 patients (1434 knees) who received treatment with a mechanical compression device only for prevention of DVT after primary TKA. The prevalence of DVT was 6.6% (94 of 1434 knees). Proximal thrombi were found in 6 of 1434 knees (0.4%). No patient had PE on perfusion lung scans. Further sonograms and venograms for the patients with thrombi at 6 months after the operation revealed that all thrombi were resolved.

Comparison of infection control rates and clinical outcomes in culture-positive and culture-negative infected total-knee arthroplasty.

BACKGROUND: To compare the outcomes of the culture positive and the culture negative infected TKA. METHODS: We determined the infection control rate in the 242 patients (140 patients with culture-positive and 102 patients with culture-negative diagnoses) with infected TKAs. RESULTS: The overall infection control rate was 90% in the culture positive group and 95% in the culture negative group. INTERPRETATION: The infection control rates and clinical outcomes of infected TKAs was not different between culture-positive and culture-negative groups.

Prevalence of deep vein thrombosis and pulmonary embolism treated with mechanical compression device after total hip arthroplasty.

Several reports have suggested that there is a strikingly low prevalence of deep vein thrombosis (DVT) and pulmonary embolism (PE) after total hip arthroplasty (THA) in Asian patients. We determined the prevalence of DVT and PE after the use of a mechanical compression device only without pharmacological thromboprophylaxis in 459 patients (516 hips). The overall prevalence of DVT was 4.8% (27 of 561 hips). Nine of 27 hips had proximal thrombi. Three patients (0.7%) had asymptomatic PE. In our patients, combinations of absent thrombophilic polymorphisms with low clinical prothrombotic risk factors led to a low prevalence of DVT and virtually no symptomatic PE. Therefore, mechanical compression device only suffices to prevent DVT and PE in Asian patients.

Long-term clinical outcomes and survivorship of press-fit condylar sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients.

BACKGROUND: We are aware of no study that has compared press-fit condylar Sigma fixed-bearing and mobile-bearing total knee prostheses in the same patients after more than ten years of follow-up. The purpose of the current study was to compare these two implants with respect to the functional and radiographic results, prevalence of osteolysis, and overall revision rates at a mean of 12.1 years of follow-up. METHODS: The study consisted of a consecutive series of 444 patients (mean age [and standard deviation], 66.5 ± 7.4 years) who underwent simultaneous bilateral total knee arthroplasty, with one side treated immediately after the other. All of the patients received a press-fit condylar Sigma mobile-bearing prosthesis on one side and a press-fit condylar Sigma fixed-bearing prosthesis on the contralateral side. The minimum duration of follow-up was ten years (mean, 12.1 years; range, ten to thirteen years). At the time of each follow-up visit, the patients were assessed clinically and radiographically. RESULTS: Postoperative total knee scores (95 and 94 points), Western Ontario and McMaster Universities Osteoarthritis Index (19 and 18 points), University of California, Los Angeles activity score (both prostheses, 5 points), range of motion (129° ± 6.3° and 127° ± 6.8°), and radiographic findings did not differ significantly between the press-fit condylar Sigma mobile and fixed-bearing designs at the final follow-up. The prevalence of aseptic loosening (1.4% and 1.8%) did not differ significantly between the mobile and fixed-bearing implant designs. No knee in either group had osteolysis. The estimated survival rate with revision as the end point was 98.2% (95% confidence interval, 91% to 99%) and 97.5% (95% confidence interval, 91% to 99%) at 12.1 years for the mobile and fixed-bearing implant groups, respectively. CONCLUSIONS: The results of the present long-term clinical study suggest that excellent clinical and radiographic results were achieved with both the press-fit condylar Sigma mobile and fixed-bearing cruciate-retaining total knee designs. We found no significant clinical advantage for a mobile-bearing over a fixed-bearing total knee prosthesis. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

A randomised prospective evaluation of ceramic-on-ceramic and ceramic-on-highly cross-linked polyethylene bearings in the same patients with primary cementless total hip arthroplasty.

PURPOSE: Very few studies have compared alumina-on-alumina ceramic and alumina-on-highly cross-linked polyethylene bearings in the same patient. The purpose of this prospective randomised study was to compare the clinical and radiographic results and the prevalence of osteolysis in cementless total hip arthroplasty using an alumina-on-alumina and alumina-on-highly cross-linked polyethylene bearings in young active patients. METHODS: We prospectively compared the results of 100 patients (200 hips) who had undergone a cementless total hip arthroplasty with an alumina-on-alumina ceramic bearing in one hip and an alumina-on-highly cross-linked polyethylene in the other. There were 66 men and 34 women with a mean age of 45.3 years (range, 21-49 years) at the time of surgery. The mean follow-up was 12.4 years (range, 11-13 years). The patients were assessed clinically and radiographically at three months, one year, and annually thereafter. RESULTS: Harris hip, Western Ontario and McMaster Universities Osteoarthritis Index, and University of California, Los Angeles activity scores did not show statistically significant differences between the two groups of bearings preoperatively or at the time of final follow-up. Radiographic findings of the component were not significantly different between the two groups. The mean polyethylene linear penetration was 0.031 ± 0.004 mm per year. No hips in either group displayed osteolysis. The Kaplan-Meier survivorship with revision as the end point at 12.4 years was 100% (95% confidence interval [CI], 94-100%) for the femoral component in both groups and 99% (95%CI, 93-100%) for the acetabular component. CONCLUSION: The clinical and radiographic results of using an alumina-on-alumina ceramic and alumina-on-highly cross-linked polyethylene bearings were similar.