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Carbon materials and their hybrid metal composites have garnered significant attention in biomedical applications due to their exceptional biocompatibility. This biocompatibility arises from their inherent chemical stability and low toxicity within biological systems. This review offers a comprehensive overview of carbon nanomaterials and their metal composites, emphasizing their biocompatibility-focused applications, including drug delivery, bioimaging, biosensing, and tissue engineering. The paper outlines advancements in surface modifications, coatings, and functionalization techniques designed to enhance the biocompatibility of carbon materials, ensuring minimal adverse effects in biological systems. A comprehensive investigation into hybrid composites integrating carbon nanomaterials is conducted, categorizing them as fullerenes, carbon quantum dots, carbon nanotubes, carbon nanofibers, graphene, and diamond-like carbon. The concluding section addresses regulatory considerations and challenges associated with integrating carbon materials into medical devices. This review culminates by providing insights into current achievements, challenges, and future directions, underscoring the pivotal role of carbon nanomaterials and their metal composites in advancing biocompatible applications.
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Zinc-air batteries (ZABs) are gaining attention as an ideal option for various applications requiring high-capacity batteries, such as portable electronics, electric vehicles, and renewable energy storage. ZABs offer advantages such as low environmental impact, enhanced safety compared to Li-ion batteries, and cost-effectiveness due to the abundance of zinc. However, early research faced challenges due to parasitic reactions at the zinc anode and slow oxygen redox kinetics. Recent advancements in restructuring the anode, utilizing alternative electrolytes, and developing bifunctional oxygen catalysts have significantly improved ZABs. Scientists have achieved battery reversibility over thousands of cycles, introduced new electrolytes, and achieved energy efficiency records surpassing 70%. Despite these achievements, there are challenges related to lower power density, shorter lifespan, and air electrode corrosion leading to performance degradation. This review paper discusses different battery configurations, and reaction mechanisms for electrically and mechanically rechargeable ZABs, and proposes remedies to enhance overall battery performance. The paper also explores recent advancements, applications, and the future prospects of electrically/mechanically rechargeable ZABs.
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With an excellent power conversion efficiency of 25.7%, closer to the Shockley-Queisser limit, perovskite solar cells (PSCs) have become a strong candidate for a next-generation energy harvester. However, the lack of stability and reliability in PSCs remained challenging for commercialization. Strategies, such as interfacial and structural engineering, have a more critical influence on enhanced performance. MXenes, two-dimensional materials, have emerged as promising materials in solar cell applications due to their metallic electrical conductivity, high carrier mobility, excellent optical transparency, wide tunable work function, and superior mechanical properties. Owing to different choices of transition elements and surface-terminating functional groups, MXenes possess the feature of tuning the work function, which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in PSCs. Furthermore, adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths, leading to enhanced conductivity and operational stability of PSCs. This review paper aims to provide an overview of the applications of MXenes as components, classified according to their roles as additives (into the perovskite absorber layer, charge transport layers, and electrodes) and themselves alone or as interfacial layers, and their significant importance in PSCs in terms of device performance and stability. Lastly, we discuss the present research status and future directions toward its use in PSCs.
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Polymer-based materials with positive temperature coefficients (PTC) are regarded as potential candidates for electrical heating elements in a wide range of applications, such as wearable electronics, soft robots, and smart skin. They offer many advantages over ceramic or metal oxide-based composites, including low resistance at room temperature, excellent flexibility and processability, and low cost. However, the electrical resistance instability and poor reproducibility have limited their use in practical applications. In this work, we prepared carbon blacks-reinforced high-density polyethylene nanocomposites (CBs-HDPE) loaded with polar additives (polyols or ionomers), which were subsequently subjected to electron beam (EB) irradiation to explore their PTC behaviors. We found that the EB-treated nanocomposites exhibited PTC behaviors, while the untreated samples showed negative temperature coefficients. Further, EB-ionomer-CBs-HDPE showed the highest PTC intensity of 3.01 Ω·cm, which was â¼35% higher than that of EB-CBs-HDPE. These results suggested that the EB irradiation enabled a specific volume expansion behavior via enhanced crosslinking among CBs, polar additives, and HDPE, inhibiting the formation of conductive networks in the nanocomposites. Thus, it can be concluded that polar additives and further EB irradiation played an important role in enhancing the PTC performances. We believe the findings provide crucial insight for designing carbon-polymer nanocomposites with PTC behaviors in various self-regulating heating devices.
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Membranous obstruction of the inferior vena cava (MOVC) is a rare subset of Budd-Chiari syndrome (BCS) with a subacute onset that is often complicated by cirrhosis and hepatocellular carcinoma (HCC). Here we report a case of recurrent HCC in a patient with cirrhosis and BCS that was treated with several episodes of transarterial chemoembolization followed by surgical tumorectomy, whereas the MOVC was successfully treated with balloon angioplasty followed by endovascular stenting. The patient was followed up for 9.9 years without anticoagulation and experienced no stent thrombosis. After the tumorectomy, the patient was HCC-free for 4.4 years of follow-up.
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BACKGROUND: This study aims to describe the trends in the severity and treatment modality of patients with diabetic foot ulcer (DFU) at a single tertiary referral center in Korea over the last 10 years and compare the outcomes before and after the introduction of a multidisciplinary diabetic foot team. METHODS: In this retrospective observational study, electronic medical records of patients from years 2002 to 2015 at single tertiary referral center were reviewed. Based on the year of first admission, patients were assigned to a group either before or after the year 2012, the year the diabetes team launched. RESULTS: Of the 338 patients with DFU, 229 were first admitted until the year 2011 (group A), while 109 were first admitted since the year 2012 (group B). Mean age was higher in group B, and ulcer size was larger than those of group A. Whereas duration of diabetes was longer in group B, glycemic control was improved (mean glycosylated hemoglobin, 9.48% vs. 8.50%). The proportion of minor lower extremity amputation (LEA) was increased, but length of hospital stay was decreased (73.7±79.6 days vs. 39.8±36.9 days). As critical ischemic limb increased, the proportion of major LEA was not decreased. CONCLUSION: Improved glycemic control, multidisciplinary strategies with prompt surgical treatment resulted in reduced length of hospital stay, but these measures did not reduce major LEAs. The increase in critical ischemic limb may have played a role in the unexpected outcome, and may suggest the need for increased vascular intervention strategies in DFU treatment.