Hydrodynamic acoustic plasmon resonances in semiconductor nanowires and their dimers

The hydrodynamic Drude model known from metal plasmonics also applies to semiconductor structures of sizes in between single-particle quantum confinement and bulk. But contrary to metals, for semiconductors two or more types of plasma may have to be taken into account in order to properly describe their plasmonic properties. In this combined analytical and computational study, we explore predictions of the recently proposed two-fluid hydrodynamic Drude model for the optical properties of plasmonic semiconductor nanowires, in particular for thermally excited InSb nanowires. We focus on the low-frequency acoustic surface and bulk plasmon resonances that are unique fingerprints for this model and are yet to be observed. We identify these resonances in spectra for single nanowires based on analytical calculations, and they are in complete agreement with our numerical implementation of the model. For dimers of nanowires we predict substantial increase of the extinction cross section and field enhancement of the acoustic localized surface plasmon resonance, which makes its observation in dimers more likely.Comment: I would like to inform that Dr.Abbas Zarifi is the corresponding author of this pape

Evaluation of overall survival and disease-free survival of adjuvant chemotherapy and hormone therapy in patients with breast cancer

Abstract : Background: This study evaluated the effect of adjuvant chemotherapy and hormone therapy on overall survival and disease-free survival in patients with breast cancer with hormone receptor-positive, HER2-negative tumor without lymph node involvement. Methods: Breast cancer patients with hormone receptor-positive, HER2-negative, and no lymph node involvement were included in this retrospective cohort study. Patient records were used to collect data on sex, age, time of disease onset, tumor subtype, tumor size, grade, lymphovascular and perineural involvement, ki67, and treatment protocols. Patients were divided into 2 groups: Patients who received both adjuvant chemotherapy and hormonal therapy and patients who received hormonal therapy only. Disease-free survival index (DFS) and overall survival index (OS) were evaluated. Results: Sixty-seven female patients were enrolled in this study. Of them, 68.2% received both adjuvant chemotherapy and hormonal therapy and 31.6% received hormonal therapy only. During follow-up, recurrences occurred in 8 patients. The 3-year and 5-year DFS were 93.4% and 90%, respectively. The 3-year and 5-year DFS were 94% and 92%, respectively, in patients who received both adjuvant chemotherapy and hormonal therapy, and 91% and 85%, respectively, in patients who received hormonal therapy. None of the factors studied affected the 3-year and 5-year DFS. The 3-year and 5-year DFS OS were 98.6% and 96.9%, respectively CONCLUSION: Adjuvant chemotherapy in patients with breast cancer with hormone receptor-positive, HER2-negative, and no lymph node involvement compared with similar patients receiving hormone therapy alone had no significant difference in disease-free survival index and overall survival index. Keywords: breast cancer; disease-free survival index; overall survival inde

Research Paper: First Order Energy Near Dirac Points for Graphene and Carbon Nanotubes with Arbitrary Chirality

The effective Hamiltonian describing indirect exchange interactions of type Ruderman- Kittel-Kasuya-Yosida [RKKY] between the magnetic impurities near the Dirac Points is based on the first-order energy. Besides, the points where the impurities are located are important in identifying the oscillatory behaviour of these interactions. Then in this paper, we first intend to obtain the effective Hamiltonian elements near the Dirac points for 2D graphene structures using the tight-binding approximation and then the phase factors between neighbor Dirac points are noticed. The obtained results are extended to obtain the effective Hamiltonian and then the first-order energy for carbon nanotubes. Using the quantized wave vector in the circumferential direction of nanotubes at Dirac Points, we examine the condition for nanotubes to be metallic or semiconductors. The obtained results based on the tight binding could be used to study the magnetic interactions at low energy for graphene structures as well as carbon nanotubes