Optical properties of iron-based superconductor LiFeAs single crystal

We have measured the reflectivity spectra of the iron based superconductor LiFeAs (Tc = 17.6 K) in the temperature range from 4 to 300 K. In the superconducting state (T < Tc), the clear opening of the optical absorption gap was observed below 25 cm-1, indicating an isotropic full gap formation. In the normal state (T > Tc), the optical conductivity spectra display a typical metallic behavior with the Drude type spectra at low frequencies, but we found that the introduction of the two Drude components best fits the data, indicating the multiband nature of this superconductor. A theoretical analysis of the low temperature data (T=4K < Tc) also suggests that two superconducting gaps best fit the data and their values were estimated as {\Delta}1 = 1.59 meV and {\Delta}2 = 3.15 meV, respectively. Using the Ferrell-Glover-Tinkham (FGT) sum rule and dielectric function {\epsilon}1({\omega}), the superconducting plasma frequency ({\omega}ps) is consistently estimated to be 6,665 cm-1, implying that about 59 % of the free carriers in the normal state condenses into the SC condensate. To investigate the various interband transition processes (for {\omega} > 200 cm-1), we have also performed the local-density approximation (LDA) band calculation and calculated the optical spectra of the interband transitions. The theoretical results provided a qualitative agreement with the experimental data below 4000 cm-1Comment: 19 pages, 5 figures. This paper has been accepted for publication in New Journal of Physic

Effects of nanofluids containing graphene/graphene-oxide nanosheets on critical heat flux

The superb thermal conduction property of graphene establishes graphene as an excellent material for thermal management. In this paper, we selected graphene/graphene oxide nanosheets as the additives in nanofluids. The authors interestingly found that the highly enhanced critical heat flux (CHF) in the nanofluids containing graphene/graphene-oxide nanosheets (GON) cannot be explained by both the improved surface wettability and the capillarity of the nanoparticles deposition layer. Here we highlights that the GON nanofluid can be exploited to maximize the CHF the most efficiently by building up a characteristically ordered porous surface structure due to its own self-assembly characteristic resulting in a geometrically changed critical instability wavelength.open363

Clinical implications of neoadjuvant chemotherapy in advanced endometrial cancer: a multi-center retrospective cohort study

Background : The mainstay of endometrial cancer treatment is surgical resection of tumors and postoperative adjuvant treatment is recommended if necessary. However, there is no consensus on the management of unresectable metastatic endometrial cancer. This study aimed to assess the feasibility and effectiveness of neoadjuvant chemotherapy followed by interval debulking surgery (NAC-IDS) in unresectable, metastatic endometrial cancer. Methods : From the endometrial cancer cohorts of four institutions in Korea, we identified patients with International Federation of Gynecology and Obstetrics stages IIIC–IVB endometrial cancer who received NAC-IDS between January 2008 and December 2020. Through a medical record review, we collected patients’ clinicopathological data. Progression-free survival (PFS), overall survival (OS), and the factors affecting survival outcomes were analyzed. Results : Overall, 32 patients were included with endometrioid (n = 18), serous (n = 5), carcinosarcoma (n = 6), and other histological types (n = 3). Among them, 28 (87.5%) patients had stage IVB disease. The most common neoadjuvant chemotherapy (NAC) regimen was paclitaxel-carboplatin (n = 25, 78.1%), which was administered for a median of six cycles. While 26 (81.3%) patients showed an objective response, two (6.3%) progressed despite NAC. At the time of interval debulking surgery (IDS), 23 (71.9%) patients achieved complete cytoreduction. During 31.0 months of the median follow-up, there were 23 recurrences and 11 deaths, corresponding to a median PFS of 19.7 months and a 3-year OS rate of 69.7%. In multivariate analyses, non-endometrioid histology and residual tumor after IDS were identified as independent poor prognostic factors for PFS (adjusted hazard ratio [HR], 7.322; P < 0.001 and 5.934; P = 0.001, respectively). Multivariate analysis for OS could not be conducted because of the small number of events, although non-endometrioid histology was the only factor associated with worse OS in univariate analysis (adjusted HR, 4.523; P = 0.032). Conclusions : NAC-IDS may be a treatment option for unresectable metastatic endometrial cancer. Tumor histology and the possibility of complete cytoreduction are the primary considerations for NAC-IDS

Cutaneous Polyarteritis Nodosa Presented with Digital Gangrene: A Case Report

Cutaneous polyarteritis nodosa (CPAN) is an uncommon form of vasculitis involving small and medium sized arteries of unknown etiology. The disease can be differentiated from polyarteritis nodosa by its limitation to the skin and lack of progression to visceral involvement. The characteristic manifestations are subcutaneous nodule, livedo reticularis, and ulceration, mostly localized on the lower extremity. Arthralgia, myalgia, peripheral neuropathy, and constitutional symptoms such as fever and malaise may also be present. We describe a 34-yr-old woman presented with severe ischemic change of the fingertip and subcutaneous nodules without systemic manifestations as an unusual initial manifestation of CPAN. Therapy with corticosteroid and alprostadil induce a moderate improvement of skin lesions. However, necrosis of the finger got worse and the finger was amputated

A Case of Cicatricial Alopecia Associated with Erlotinib

Erlotinib is a small-molecule tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR). Erlotinib has been used primarily to treat non-small cell lung cancer. In addition to its role in tumor cells, EGFR is also an important regulator of growth and differentiation in the skin and hair. Therefore, EGFR-TKIs have been associated with a number of cutaneous side effects including follicular acneiform eruptions, cutaneous xerosis, chronic paronychia, desquamation, seborrheic dermatitis, and hair texture changes. Herein, we report a rare case of a 61-year-old woman who was treated with erlotinib and experienced cicatricial alopecia

Relationship between recurrence and age in the diffuse sclerosing variant of papillary thyroid carcinoma: clinical significance in pediatric patients

BackgroundThe diffuse sclerosing variant (DSV) is among the aggressive variants of papillary thyroid carcinoma (PTC) and is more prevalent in pediatric patients than in adult patients. Few studies have assessed its characteristics owing to its low incidence. We aimed to evaluate the relationship between recurrence and age in the DSV of PTC.MethodsWe retrospectively reviewed patients diagnosed with the DSV or conventional PTC (cPTC) after surgery at a medical center between May 1988 and January 2019. We compared the clinico-pathological characteristics and surgical outcomes of the DSV and cPTC groups and between adult and pediatric patients with DSV.ResultsAmong the 24,626 patients, 202 had the DSV, and 24,424 were diagnosed with cPTC. The recurrence rate was significantly higher in the DSV group than in the cPTC group. In the DSV group, the recurrence rate was significantly higher in the pediatric patient group than in the adult patient group. Moreover, the association between recurrence and age group showed different patterns between the DSV and cPTC groups with restricted cubic splines (RCS). While both RCS curves showed a U-shaped distribution, the RCS curve tended to be located within the younger age group.ConclusionsThis study demonstrated that pediatric patients with DSV are at a greater risk for recurrence compared with adult patients; moreover, the pattern of recurrence risk according to age is different from that of cPTC

A Case of Recurrent Neuro-Behçet's Disease after Tooth Extraction

We report a 39-yr-old man with neuro-Behçet's disease (NBD) in remission who developed left-sided ataxia with a sensory deficit about 10 days after tooth extraction. Several years ago, he experienced a similar episode of relapse after tooth extraction. Brain magnetic resonance imaging showed a newly developed right thalamic lesion. In cerebrospinal fluid, lymphocyte-dominant pleocytosis and mild elevation of IgG were found. Immunologic factors may be important in the pathogenesis of NBD because of the time delay between tooth extraction and relapse. Careful observation and prevention are needed before dental procedures in patients with NBD