Antimony-doped graphene nanoplatelets

Heteroatom doping into the graphitic frameworks have been intensively studied for the development of metal-free electrocatalysts. However, the choice of heteroatoms is limited to non-metallic elements and heteroatom-doped graphitic materials do not satisfy commercial demands in terms of cost and stability. Here we realize doping semimetal antimony (Sb) at the edges of graphene nanoplatelets (GnPs) via a simple mechanochemical reaction between pristine graphite and solid Sb. The covalent bonding of the metalloid Sb with the graphitic carbon is visualized using atomic-resolution transmission electron microscopy. The Sb-doped GnPs display zero loss of electrocatalytic activity for oxygen reduction reaction even after 100,000 cycles. Density functional theory calculations indicate that the multiple oxidation states (Sb3+ and Sb5+) of Sb are responsible for the unusual electrochemical stability. Sb-doped GnPs may provide new insights and practical methods for designing stable carbon-based electrocatalystsclose0

Direct nitrogen fixation at the edges of graphene nanoplatelets as efficient electrocatalysts for energy conversion

Nitrogen fixation is essential for the synthesis of many important chemicals (e.g., fertilizers, explosives) and basic building blocks for all forms of life (e.g., nucleotides for DNA and RNA, amino acids for proteins). However, direct nitrogen fixation is challenging as nitrogen (N2) does not easily react with other chemicals. By dry ball-milling graphite with N2, we have discovered a simple, but versatile, scalable and eco-friendly, approach to direct fixation of N2 at the edges of graphene nanoplatelets (GnPs). The mechanochemical cracking of graphitic C-C bonds generated active carbon species that react directly with N2 to form five- and six-membered aromatic rings at the broken edges, leading to solution-processable edge-nitrogenated graphene nanoplatelets (NGnPs) with superb catalytic performance in both dye-sensitized solar cells and fuel cells to replace conventional Pt-based catalysts for energy conversion.open302

Understanding how excess lead iodide precursor improves halide perovskite solar cell performance

The presence of excess lead iodide in halide perovskites has been key for surpassing 20% photon-to-power conversion efficiency. To achieve even higher power conversion efficiencies, it is important to understand the role of remnant lead iodide in these perovskites. To that end, we explored the mechanism facilitating this effect by identifying the impact of excess lead iodide within the perovskite film on charge diffusion length, using electron-beam-induced current measurements, and on film formation properties, from grazing-incidence wide-angle X-ray scattering and high-resolution transmission electron microscopy. Based on our results, we propose that excess lead iodide in the perovskite precursors can reduce the halide vacancy concentration and lead to formation of azimuthal angle-oriented cubic alpha-perovskite crystals in-between 0 degrees and 90 degrees. We further identify a higher perovskite carrier concentration inside the nanostructured titanium dioxide layer than in the capping layer. These effects are consistent with enhanced lead iodide-rich perovskite solar cell performance and illustrate the role of lead iodide

Inkjet Printing Based Mono-layered Photonic Crystal Patterning for Anti-counterfeiting Structural Colors

Photonic crystal structures can be created to manipulate electromagnetic waves so that many studies have focused on designing photonic band-gaps for various applications including sensors, LEDs, lasers, and optical fibers. Here, we show that mono-layered, self-assembled photonic crystals (SAPCs) fabricated by using an inkjet printer exhibit extremely weak structural colors and multiple colorful holograms so that they can be utilized in anti-counterfeit measures. We demonstrate that SAPC patterns on a white background are covert under daylight, such that pattern detection can be avoided, but they become overt in a simple manner under strong illumination with smartphone flash light and/or on a black background, showing remarkable potential for anti-counterfeit techniques. Besides, we demonstrate that SAPCs yield different RGB histograms that depend on viewing angles and pattern densities, thus enhancing their cryptographic capabilities. Hence, the structural colorations designed by inkjet printers would not only produce optical holograms for the simple authentication of many items and products but also enable a high-secure anti-counterfeit techniqueope

Effectiveness of bronchoscopic lung volume reduction using unilateral endobronchial valve: a systematic review and meta-analysis.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) can be suggested as an alternative for surgical lung volume reduction surgery for severe emphysema patients. This article intends to evaluate by systematic review the safety and effectiveness of BLVR using a one-way endobronchial valve. METHODS: A systematic search of electronic databases, including MEDLINE, EMBASE, and the Cochrane Library, as well as eight domestic databases up to December 2013, was performed. Two reviewers independently screened all references according to selection criteria. The Scottish Intercollegiate Guidelines Network criterion was used to assess quality of literature. Data from randomized controlled trials were combined and meta-analysis was performed. RESULTS: This review included 15 studies. Forced expiratory volume in 1 second (FEV1) improved in the intervention group compared with the control group (mean difference [MD]=6.71, 95% confidence interval [CI]: 3.31-10.11). Six-minute walking distance (MD=15.66, 95% CI: 1.69-29.64) and cycle workload (MD=4.43, 95% CI: 1.80-7.07) also improved. In addition, St George's Respiratory Questionnaire score decreased (MD=4.29, 95% CI: -6.87 to -1.71) in the intervention group. In a subgroup analysis of patients with complete fissure, the FEV1 change from baseline was higher in the BLVR group than in the control group for both 6 months (MD=15.28, P<0.001) and 12 months (MD=17.65, P<0.001), whereas for patients with incomplete fissure, FEV1 and 6-minute walking distance showed no change. One-year follow-up randomized controlled trials reported deaths, although the cause of death was not related to BLVR. Respiratory failure and pneumothorax incidence rates were relatively higher in the BLVR group, but the difference was not significant. CONCLUSION: BLVR may be an effective and safe procedure for the treatment of severe COPD patients with emphysema, based on existing studies

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Evaluation of the Current Urgency-Based Lung Allocation System in Korea with Simulation of the Eurotransplant Lung Allocation Score

Purpose: Due to the shortage of lung donors relative to the number of patients waiting for lung transplantation (LTx), more than one-third of patients on the waitlist have died without receiving LTx in Korea. Therefore, the importance of fair and effective allocation policies has been emphasized. This study investigated the characteristics of the current urgency-based allocation system in Korea by simulating the Eurotransplant lung allocation score (ET-LAS) using a nationwide multi-institutional registry for LTx in Korea. Materials and Methods: This study used data from the Korean Organ Transplantation Registry (KOTRY), along with additional retrospective data for ET-LAS calculation. A total of 194 patients were included in this study between January 2015 and December 2019. The Korean urgency definition classifies an LTx candidate as having statuses 0–3 according to urgency. The ET-LAS was analyzed according to the Korean urgency status. Results: In total, 92 patients received lung transplants at status 0, 85 at status 1, and 17 at status 2/3. The ET-LAS showed a bimodal distribution with distinct peaks corresponding to status 0 and non-status 0. There was no significant difference in the ET-LAS among non-status 0 patients. In logistic and decision tree analyses, oxygen supplementation methods, particularly oxygen masks and high-flow nasal cannulas, were significantly associated with a high ET-LAS (≥50) among non-status 0 patients. Conclusion: Simulation of the ET-LAS with KOTRY data showed that the Korean urgency definition may not allocate lungs by urgency, especially for patients in non-status 0; therefore, it needs to be revised

Outcomes of Patients on the Lung Transplantation Waitlist in Korea: A Korean Network for Organ Sharing Data Analysis

BACKGROUND: The demand for lung transplants continues to increase in Korea, and donor shortages and waitlist mortality are critical issues. This study aimed to evaluate the factors that affect waitlist outcomes from the time of registration for lung transplantation in Korea. METHODS: Data were obtained from the Korean Network for Organ Sharing for lung-only registrations between September 7, 2009, and December 31, 2020. Post-registration outcomes were evaluated according to the lung disease category, blood group, and age. RESULTS: Among the 1,671 registered patients, 49.1% had idiopathic pulmonary fibrosis (group C), 37.0% had acute respiratory distress syndrome and other interstitial lung diseases (group D), 7.2% had chronic obstructive pulmonary disease (group A), and 6.6% had primary pulmonary hypertension (group B). Approximately half of the patients (46.1%) were transplanted within 1 year of registration, while 31.8% died without receiving a lung transplant within 1 year of registration. Data from 1,611 patients were used to analyze 1-year post-registration outcomes, which were classified as transplanted (46.1%, n = 743), still awaiting (21.1%, n = 340), removed (0.9%, n = 15), and death on waitlist (31.8%, n = 513). No significant difference was found in the transplantation rate according to the year of registration. However, significant differences occurred between the waitlist mortality rates (P = 0.008) and the still awaiting rates (P = 0.009). The chance of transplantation after listing varies depending on the disease category, blood type, age, and urgency status. Waitlist mortality within 1 year was significantly associated with non-group A disease (hazard ratio [HR], 2.76, P &lt; 0.001), age &gt;/= 65 years (HR, 1.48, P &lt; 0.001), and status 0 at registration (HR, 2.10, P &lt; 0.001). CONCLUSION: Waitlist mortality is still higher in Korea than in other countries. Future revisions to the lung allocation system should take into consideration the high waitlist mortality and donor shortages

Serum Proteins, HMMR, NXPH4, PITX1 and THBS4; A Panel of Biomarkers for Early Diagnosis of Hepatocellular Carcinoma

The high morbidity rate of hepatocellular carcinoma (HCC) is mainly linked to late diagnosis. Early diagnosis of this leading cause of mortality is therefore extremely important. We designed a gene selection strategy to identify potential secretory proteins by predicting signal peptide cleavage sites in amino acid sequences derived from transcriptome data of human multistage HCC comprising chronic hepatitis, liver cirrhosis and early and overt HCCs. The gene selection process was validated by the detection of molecules in the serum of HCC patients. From the computational approaches, 10 gene elements were suggested as potent candidate secretory markers for detecting HCC patients. ELISA testing of serum showed that hyaluronan mediated motility receptor (HMMR), neurexophilin 4 (NXPH4), paired like homeodomain 1 (PITX1) and thrombospondin 4 (THBS4) are early-stage HCC diagnostic markers with superior predictive capability in a large cohort of HCC patients. In the assessment of differential diagnostic accuracy, receiver operating characteristic curve analyses showed that HMMR and THBS4 were superior to alpha-fetoprotein (AFP) in diagnosing HCC, as evidenced by the high area under the curve, sensitivity, specificity, accuracy and other values. In addition, comparative analysis of all four markers and AFP combinations demonstrated that HMMR-PITX1-AFP and HMMR-NXPH4-PITX1 trios were the optimal combinations for reaching 100% accuracy in HCC diagnosis. Serum proteins HMMR, NXPH4, PITX1 and THBS4 can complement measurement of AFP in diagnosing HCC and improve identification of patients with AFP-negative HCC as well as discriminate HCC from non-malignant chronic liver disease

Predicting clinically unrecognized coronary artery disease: use of two- dimensional echocardiography

<p>Abstract</p> <p>Background</p> <p>2-D Echo is often performed in patients without history of coronary artery disease (CAD). We sought to determine echo features predictive of CAD.</p> <p>Methods</p> <p>2-D Echo of 328 patients without known CAD performed within one year prior to stress myocardial SPECT and angiography were reviewed. Echo features examined were left ventricular and atrial enlargement, LV hypertrophy, wall motion abnormality (WMA), LV ejection fraction (EF) < 50%, mitral annular calcification (MAC) and aortic sclerosis/stenosis (AS). High risk myocardial perfusion abnormality (MPA) was defined as >15% LV perfusion defect or multivessel distribution. Severe coronary artery stenosis (CAS) was defined as left main, 3 VD or 2VD involving proximal LAD.</p> <p>Results</p> <p>The mean age was 62 ± 13 years, 59% men, 29% diabetic (DM) and 148 (45%) had > 2 risk factors. Pharmacologic stress was performed in 109 patients (33%). MPA was present in 200 pts (60%) of which, 137 were high risk. CAS was present in 166 pts (51%), 75 were severe. Of 87 patients with WMA, 83% had MPA and 78% had CAS. Multivariate analysis identified age >65, male, inability to exercise, DM, WMA, MAC and AS as independent predictors of MPA and CAS. Independent predictors of high risk MPA and severe CAS were age, DM, inability to exercise and WMA.</p> <p>2-D echo findings offered incremental value over clinical information in predicting CAD by angiography. (Chi square: 360 vs. 320 p = 0.02).</p> <p>Conclusion</p> <p>2-D Echo was valuable in predicting presence of physiological and anatomical CAD in addition to clinical information.</p