Theoretical investigation of superconductivity in SrAuSi3 and SrAu2Si2

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Available online 8 April 2016The structural and electronic properties of BaNiSn3-type SrAuSi3 and ThCr2Si2-type SrAu2Si2 have been investigated by using the planewave pseudopotential method and the density functional theory. The electronic structures and phonon dispersion relations of these two materials have been analyzed with and without the inclusion of spin-orbit interaction, and similarities and differences highlighted. By integrating the Eliashberg spectral function α2F(ω), the average electron-phonon coupling parameter is determined to be λ=0.47 for SrAuSi3 and 0.42 for SrAu2Si2. The largest contribution to the electron-phonon coupling for SrAuSi3 comes from the Si p electrons near the Fermi energy and Si-related vibrations. Using a reasonable value of μ∗=0.12 for the effective Coulomb repulsion parameter, the superconducting critical temperature Tc for SrAuSi3 is found to be 1.47 K which compares very well with its experimental value of 1.54 K.This work was supported by the Scientific and Technical Research Council of Turkey (TÜBİTAK) (Project no. MFAG-115F135)

The effect of spin orbit interaction for superconductivity in the noncentrosymmetric superconductor CaIrSi3

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.We have carried out an ab initio study of the electronic, vibrational and electron-phonon interaction properties of the body-centred tetragonal CaIrSi3 by employing the density functional theory, a linear-response formalism, and the plane-wave pseudopotential method. The electronic structure and phonon dispersion relations of this material have been analyzed with and without the inclusion of spin-orbit interaction (SOI). Our electron-phonon interaction results reveal that Si-related phonon modes are more involved in the process of scattering of electrons than the remaining phonon modes due to considerable existence of the Si 3p states near the Fermi level. By integrating the Eliashberg spectral function, the average electron-phonon coupling parameter is found to be 0.58 which compares very well with its experimental value of 0.56. Using the calculated value of λ, the superconducting critical temperature (Tc) for CaIrSi3 is found to be 3.20 K which is in good accordance with its experimental value of 3.55 K. Furthermore, we have shown that the effect of SOI on the values of λ and Tc is very small.This work was supported by the Scientific and Technical Research Council of Turkey (TÜBİTAK) (Project Number MFAG-115F135)

Prognostic factors of perioperative FLOT regimen in operable gastric and gastroesophageal junction tumors: real-life data (Turkish Oncology Group)

Background/aim: Perioperative FLOT regimen is a standard of care in locally advanced operable gastric and GEJ adenocarcinoma. We aimed to determine the efficacy, prognostic factors of perioperative FLOT chemotherapy in real-life gastric and GEJ tumors. Materials and methods: The data of patients who were treated with perioperative FLOT chemotherapy were retrospectively analyzed from 34 different oncology centers in Turkey. Baseline clinical and demographic characteristics, pretreatment laboratory values, histological and molecular characteristics were recorded. Results: A total of 441 patients were included in the study. The median of age our study population was 60 years. The majority of patients with radiological staging were cT3-4N(+) (89.9%, n = 338). After median 13.5 months (IQR: 8.5–20.5) follow-up, the median overall survival was NR (95% CI, NR to NR), and median disease free survival was 22.9 (95% CI, 18.6 to 27.3) months. The estimated overall survival at 24 months was 62%. Complete pathological response (pCR) and near pCR was achieved in 23.8% of all patients. Patients with lower NLR or PLR have significantly longer median OS (p = 0.007 and p = 0.033, respectively), and patients with lower NLR have significantly longer median DFS (p = 0.039), but PLR level did not affect DFS (p = 0.062). The OS and DFS of patients with better ECOG performance scores and those who could receive FLOT as adjuvant chemotherapy instead of other regimens were found to be better. NLR was found to be independent prognostic factor for OS in the multivariant analysis. At least one adverse event reported in 57.6% of the patients and grade 3–4 toxicity was seen in 23.6% patients. Conclusion: Real-life perioperative FLOT regimen in operable gastric and GEJ tumors showed similar oncologic outcomes compared to clinical trials. Better performance status, receiving adjuvant chemotherapy as same regimen, low grade and low NLR and PLR improved outcomes in real-life. However, in multivariate analysis, only NLR affected OS. © TÜBİTAK

Recovery from Posttraumatic Stress Symptoms: A Qualitative Study of Attributions in Survivors of War

This study was funded by a grant from the European Commission, contract number INCO-CT-2004-50917

Effect of active and passive smoking on asthma exacerbations and severity in asthma patients followed up regularly [Düzenli i·zlenen astim olgularinda aktif - Pasif sigara içme durumunun astim ataklari ve hastalik şiddeti ile ilişkisi]

Objective: Both active and passive smoking increase the risk of developing asthma and respiratory symptoms and decrease pulmonary functions. The aim of this study was to investigate the effects of active and passive smoking exposure on asthma severity and exacerbations in patients treated and followed-up regularly by the same physician in a specialized asthma outpatient clinic. Material and Method: We used a questionnaire to assess the history, medications, severity and exacerbations of asthma, besides active and passive smoking exposure in 131 patients attending our asthma outpatient clinic and urinary cotinine levels were measured. Results: Mean age of the patients was 52.0±11.7 [93 females (71%)]. Thirty nine patients (30%) reported passive smoking exposure, whereas seven (5%) patients were current smokers. Urinary cotinine levels were high (>500 ng/ml) in only two patients with passive smoking exposure. The average number of asthma exacerbations was 1.5/year in patients exposed to passive smoking and 1/year in patients without exposure (p>0.05). The number of patients with intermittent (32% vs. 24%) and mild persistent (53% vs. 46%) asthma were higher in passive smoking patients whereas there were more patients without smoking exposure in the moderate persistent (13% vs. 22%) and severe persistent (3% vs. 8%) groups. Conclusion: We concluded that the percentage of current smokers was lower than the general population among asthma patients. This can emphasize the importance of educational therapy in the specific asthma outpatient clinic. On the other hand, we should improve the consciousness of the general public about asthma as one third of the patients were passive smokers

Can impairments of thyroid function test affect prognosis in patients with respiratory failure?

PubMed ID: 18224499Thyroid function test (TFT) impairments can be detected in extrathyroidal dysfunction, primarily in chronic obstructive pulmonary disease (COPD) with acute respiratory failure (RF). The aims of this study were to: (i) evaluate TFT impairments in patients with RF, (ii) compare TFT results to a control group without RF and (iii) assess the effects of thyroid dysfunction on clinical outcome and prognosis of RF. The TFT parameters were assessed in 65 patients (65.0 ± 10.0 years, 49 males) with RF and compared to 18 patients (64.4 ± 9.8 years, 13 males) with lung disease and no RF (p> 0.05). Arterial blood I gas analysis, free T3 (FT3), free T4 (FT4) and TSH levels were all measured. The impairments of TFT were demonstrated in \ 34 (52.3%) patients with RF and 8 (44.4%) patients without RF (p> 0.05). The most common finding was a decrease in at least one of the TFT parameters in both groups (43.1% vs. 44.4%, respectively), in RF group, there was no significant association between TFT results and gender, age, diagnosis and co-morbid disease. However, need for invasive mechanical ventilation was higher both in patients with low FT3 and low FT4 when compared to those with normal TFT results (p= 0.001 and p= 0.003, respectively). In-hospital mortality rate was also higher both in the patients with low FT3 and low FT4 than the others (p= 0.006 and p= 0.07, respectively). We conclude that TFT impairments are not observed more frequently in patients with RF when compared to the patients without RF. However, low FT3 and FT4 levels increase the rates of invasive mechanical ventilation and mortality

The comparison of patients with hospitalized health-care-associated pneumonia to community-acquired pneumonia [Sagli{dotless}k baki{dotless}mi{dotless} ile ilişkili pnömoni ve toplum kökenli pnömoni tani{dotless}lari{dotless} ile hastanede yatan olgulari{dotless}n karşi{dotless}laşti{dotless}ri{dotless}lmasi{dotless}]

PubMed ID: 22233304Health-care-associated pneumonia (HCAP) is defined as pneumonia that develops in patients with a history of recent hospitalization, hemodialysis as an outpatient, residence in a nursing home, outpatient intravenous therapy and home wound care. We aimed to compare the initial demographic characteristics, causative agents and prognosis between hospitalized HCAP and community-acquired pneumonia (CAP) patients. HCAP and CAP patients hospitalized between 01 September 2008-01 September 2009 were evaluated retrospectively. Out of 187 patients (131 males, mean age 66.3 ± 14.3 years) who were hospitalized during one-year period, 98 were diagnosed as HCAP and 89 as CAP. Among HCAP patients, 64 (65.3%) had a history of hospitalization in the last 90 days, 26 (26.5%) received outpatient intravenous therapy, 17 (17.3%) had home wound care, 6 (6.1%) were on hemodialysis program in the last 30 days and 4 (4.1%) lived in a nursing home. The causative patogen was detected in 39 (39.8%) HCAP and 8 (9.0%) CAP patients. The most frequently isolated microorganisms were Pseudomonas aeruginosa and Acinetobacter baumannii in HCAP, and Streptococcus pneumoniae and Haemophilus influenzae in CAP patients. Inappropriate empiric antibiotic treatment was documented in 8 (25.8%) of 39 HCAP patients, in whom a causative agent was isolated whereas the antibiotic treatment was appopriate in all CAP patients. The duration of hospitalization (14.4 ± 11.4 vs. 10.7 ± 7.9 days, p= 0.011) and mortality rate (34.7% vs. 9.0%, p< 0.001) were higher in HCAP compared with CAP patients. As HCAP is different than CAP in terms of patients' characteristics, causative microorganisms and prognosis, it should be considered in all patients hospitalized as CAP. Potentially drug-resistant microorganisms should be taken into consideration in the empirical antibiotic treatment of these patients