RESUMEN
BACKGROUND: Early screening and detection of lung cancer is essential for the diagnosis and prognosis of the disease. In this paper, we investigated the feasibility of serum Raman spectroscopy for rapid lung cancer screening. METHODS: Raman spectra were collected from 45 patients with lung cancer, 45 with benign lung lesions, and 45 healthy volunteers. And then the support vector machine (SVM) algorithm was applied to build a diagnostic model for lung cancer. Furthermore, 15 independent individuals were sampled for external validation, including 5 lung cancer patients, 5 benign lung lesion patients, and 5 healthy controls. RESULTS: The diagnostic sensitivity, specificity, and accuracy were 91.67%, 92.22%, 90.56% (lung cancer vs. healthy control), 92.22%,95.56%,93.33% (benign lung lesion vs. healthy) and 80.00%, 83.33%, 80.83% (lung cancer vs. benign lung lesion), repectively. In the independent validation cohort, our model showed that all the samples were classified correctly. CONCLUSION: Therefore, this study demonstrates that the serum Raman spectroscopy analysis technique combined with the SVM algorithm has great potential for the noninvasive detection of lung cancer.
Asunto(s)
Neoplasias Pulmonares , Espectrometría Raman , Máquina de Vectores de Soporte , Humanos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/diagnóstico , Espectrometría Raman/métodos , Estudios de Casos y Controles , Masculino , Femenino , Persona de Mediana Edad , Anciano , Detección Precoz del Cáncer/métodos , Adulto , Sensibilidad y Especificidad , Algoritmos , Biomarcadores de Tumor/sangreRESUMEN
Low-dimensional Ruddlesden-Popper (LDRP) perovskites still suffer from inferior carrier transport properties. Here, we demonstrate that efficient exciton dissociation and charge transfer can be achieved in LDRP perovskite by introducing γ-aminobutyric acid (GABA) as a spacer. The hydrogen bonding links adjacent spacing sheets in (GABA)2 MA3 Pb4 I13 (MA=CH3 NH3 + ), leading to the charges localized in the van der Waals gap, thereby constructing "charged-bridge" for charge transfer through the spacing region. Additionally, the polarized GABA weakens dielectric confinement, decreasing the (GABA)2 MA3 Pb4 I13 exciton binding energy as low as ≈73â meV. Benefiting from these merits, the resultant GABA-based solar cell yields a champion power conversion efficiency (PCE) of 18.73 % with enhanced carrier transport properties. Furthermore, the unencapsulated device maintains 92.8 % of its initial PCE under continuous illumination after 1000â h and only lost 3 % of its initial PCE under 65 °C for 500â h.
RESUMEN
In recent years, 2D Ruddlesden-Popper (2DRP) perovskite materials have been explored as emerging semiconductor materials in solar cells owing to their excellent stability and structural diversity. Although 2DRP perovskites have achieved photovoltaic efficiencies exceeding 19%, their widespread use is hindered by their inferior charge-carrier transport properties in the presence of diverse organic spacer cations, compared to that of traditional 3D perovskites. Hence, a systematic understanding of the carrier transport mechanism in 2D perovskites is critical for the development of high-performance 2D perovskite solar cells (PSCs). Here, the recent advances in the carrier behavior of 2DRP PSCs are summarized, and guidelines for successfully enhancing carrier transport are provided. First, the composition and crystal structure of 2DRP perovskite materials that affect carrier transport are discussed. Then, the features of 2DRP perovskite films (phase separation, grain orientation, crystallinity kinetics, etc.), which are closely related to carrier transport, are evaluated. Next, the principal direction of carrier transport guiding the selection of the transport layer is revealed. Finally, an outlook is proposed and strategies for enhancing carrier transport in high-performance PSCs are rationalized.