Cross-sectional analysis for lymphedema epidemiology in South Korea by HIRA data: An observational study.

Lymphedema is known to affect as many as 140 to 250 million people worldwide. Approximately 99% of lymphedemas are secondary cases after lymphadenectomy, radiation, or parasite infection. There has been no accurate estimate of the lymphedema population size in South Korea. This study aimed to quantify the epidemiology of lymphedema in South Korea and analyze the clinical characteristics of patients with lymphedema using a nationwide database. This large-scale cross-sectional study included patients who received one of the following three diagnostic codes - Q82.0 (hereditary lymphedema), I97.2 (breast cancer-related lymphedema), and I89.0 (unclassified lymphedema) from the Korean Health Insurance Review and Assessment service between January 2019 and July 2022 at tertiary hospitals, general hospitals, or other hospitals. The demographics of the lymphedema population, medication use, and medical characteristics were identified. Over the last 4 years, the annual incidence of lymphedema has steadily increased and peaked in 2021 with the number 1.85 out of 1000. Of all patients, 81% were located in the upper extremity, and 10.6% had previous cancer. Most patients were diagnosed in general hospitals (53.2%), at orthopedic surgery department (41.9%). On average, lymphedema patients spent 70.17 US dollar for medication and hospitalized for 16.9 days annually after diagnosis. Commonly prescribed medications were Entelon® (Vitis vinifera seed extract) (66.9%), steroids (40.5%), non-steroidal anti-inflammatory drugs (26.5%) and diuretics (21.8%). Only 5.7% of patients received surgery and 19.2% received herbal medicine. This is the first study in South Korea to quantify demographic and medical characteristics of lymphedema patients. These results will contribute to a comprehensive understanding of lymphedema diagnosis and treatment in our nation.

Anomalous Correlation between Thermal Conductivity and Elastic Modulus in Two-Dimensional Hybrid Metal Halide Perovskites.

Device-level implementation of soft materials for energy conversion and thermal management demands a comprehensive understanding of their thermal conductivity and elastic modulus to mitigate thermo-mechanical challenges and ensure long-term stability. Thermal conductivity and elastic modulus are usually positively correlated in soft materials, such as amorphous macromolecules, which poses a challenge to discover materials that are either soft and thermally conductive or hard and thermally insulative. Here, we show anomalous correlations of thermal conductivity and elastic modulus in two-dimensional (2D) hybrid organic-inorganic perovskites (HOIP) by engineering the molecular interactions between organic cations. By replacing conventional alkyl-alkyl and aryl-aryl type organic interactions with mixed alkyl-aryl interactions, we observe an enhancement in elastic modulus with a reduction in thermal conductivity. This anomalous dependence provides a route to engineer thermal conductivity and elastic modulus independently and a guideline to search for better thermal management materials. Further, introducing chirality into the organic cation induces a molecular packing that leads to the same thermal conductivity and elastic modulus regardless of the composition across all half-chiral 2D HOIPs. This finding provides substantial leeway for further investigations in chiral 2D HOIPs to tune optoelectronic properties without compromising thermal and mechanical stability.