Effect of Alkali Metal Atom Doping on the CuInSe2-Based Solar Cell Absorber

The efficiency of Cu(In,Ga)Se_2 (CIGS)-based solar cells can bemarkedly improved by controlled introduction of alkali metal (AM) atomsusing post-deposition treatment (PDT) after CIGS growth. Previous studieshave indicated that AM atoms may act as impurities or agglomerate intosecondary phases. To enable further progress, understanding of atomic levelprocesses responsible for these improvements is required. To this end, we haveinvestigated theoretically the effects of the AM elements Li, Na, K, Rb, and Cson the properties of the parent material CuInSe_2 . First, the effects of the AMimpurities in CuInSe_2 have been investigated in terms of formation energies,charge transition levels, and migration energy barriers. We found that AM atoms preferentially substitute for Cu atoms at theneutral charge state. Under In-poor conditions, AM atoms at the In site also show low formation energies and are acceptors. Themigration energy barriers show that the interstitial diffusion mechanism may be relevant only for Li, Na, and K, whereas all theAM atoms can diffuse with the help of Cu vacancies. The competition between these two mechanisms strongly depends on theconcentration of Cu vacancies. We also discuss how AM atoms can contribute to increasing Cu-depleted regions. Second, AMatoms can form secondary phases with Se and In atoms. We suggest a mechanism for the secondary phase formation followingthe PDT process. On the basis of the calculated reaction enthalpies and migration considerations, we find that mixed phases aremore likely in the case of LiInSe_2 and NaInSe_2 , whereas formation of secondary phases is expected for KInSe_2 , RbInSe_2 , andCsInSe_2 . We discuss our findings in the light of experimental results obtained for AM treatments. The secondary phases havelarge energy band gaps and improve the morphology of the buffer surface by enabling a favorable band alignment, which canimprove the electrical properties of the device. Moreover, they can also passivate the surface by forming a diffusion barrier.Overall, our work points to different roles played by the light and heavy AM atoms and suggests that both types may be neededto maximize their benefits on the solar cell performance.Peer reviewe

The impact of malignant nipple discharge cytology (NDc) in surgical management of breast cancer patients

BACKGROUND: The role of nipple discharge cytology (NDc) in the surgical management of breast cancer patients is unclear. We aimed: (i) to evaluate the effect of malignant NDc on the surgical approach to the nipple-areola complex, and (ii) to verify the association between malignant NDc and nipple malignancy. METHODS: We retrospectively analyzed a case series of 139 patients with NDc who underwent breast surgery. The clinical and histological findings, types of surgery with emphasis on nipple-areola complex amputation, immunohistochemical phenotypes of the carcinomas and measurements of the tumor-nipple distance were recorded. Additionally, in patients who showed HER2-positive lesions on definitive surgery, we evaluated the HER2 immunocytochemistry of the NDc smears. RESULTS: Thirty-two malignant and 107 benign/borderline NDc diagnoses were identified. All 32 malignant-NDc cases were histologically confirmed as malignant. Thirty borderline/benign-NDc cases were histologically diagnosed as malignant (sensitivity 58%). The majority of the patients with malignant NDc were treated with nipple-areola complex amputations in both the mastectomy and conservative surgery groups (P<0.001, chi251.77). Nipple involvement was strongly associated with HER2-positive ductal carcinoma in-situ (P<0.001, chi211.98). HER2 immunocytochemistry on the NDc revealed a 100% correlation with the immunocytochemistry performed on the surgical tissues. CONCLUSIONS: Malignant NDc influenced surgical management. The association of malignant NDc with nipple involvement is highly related to ductal carcinoma in-situ with HER2 overexpression. In case of HER2 positive NDc, nipple-areola complex involvement is more likely than in HER2 negative cases

Callous-unemotional traits moderate the relation between prenatal testosterone (2D:4D) and externalising behaviours in children

Children who exhibit callous-unemotional (CU) traits are identified as developing particularly severe forms of externalising behaviours (EB). A number of risk factors have been identified in the development of CU traits, including biological, physiological, and genetic factors. However, prenatal testosterone (PT) remains un-investigated, yet could signal fetal programming of a combination of CU/EB. Using the 2D:4D digit ratio, the current study examined whether CU traits moderated the relationship between PT and EB. Hand scans were obtained from 79 children aged between 5 and 6 years old whose parents completed the parent report ICU (Inventory of Callous Unemotional Traits) and SDQ (Strengths and Difficulties Questionnaire). CU traits were found to moderate the relationship between PT and EB so that children who were exposed to increased PT and were higher in CU traits exhibited more EB. Findings emphasize the importance of recognising that vulnerability for EB that is accompanied by callousness may arise before birth

In vitro antibacterial activities of erythromycin, clarithromycin, azithromycin and cephradine against methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains

The in vitro antibacterial activities of erythromycin, clarithromycin, and azithromycin were evaluated against 75 methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains isolated from the hospital and outpatient clinics by the broth microdilution method and these activities were compared with those of cephradine. Of these strains, 35 (47%) were isolated from in-patients and 40 (53%) from out-patients. A total of 19 (54.3%) of the hospital and 16 (40%) of the outpatient-clinic isolates were resistant to methicillin as determined by the disc diffusion method. Of the methicillin-sensitive hospital isolates, 75% were also susceptible to erythromycin, clarithromycin, and azithromycin (MIC range 0.25-64 μg/ ml), and 68.7% were susceptible to cephradine. For the strains (methicillin-resistant and methicillin-sensitive) that were isolated from outpatient clinics, the overall sensitivity rates were not statistically different, although the MIC values were lower for all the agents tested when compared with hospital isolates

Molecular epidemiology of Candida species isolated from urine at an intensive care unit

Candida spp. has been the leading microorganism isolated from the urine specimens of patients hospitalized at the Anesthesiology and Reanimation intensive care unit (ICU) of Dokuz Eylul University Hospital, Izmir, since 1998. This study was undertaken to investigate the clonal relationship of Candida urine isolates in order to find the mode of spread among the patients. Epidemiological surveillance of 38 Candida albicans, 15 Candida tropicalis and 12 Candida glabrata recovered from the urine specimens of patients who were hospitalized in the ICU between June 11, 2000 and October 15, 2001 was carried out by antifungal susceptibility testing and randomly amplified polymorphic DNA (RAPD) analysis. Two short primers [Cnd3 (5'-CCAGATGCAC-3') and Cnd4 (5'-ACGGTACACT-3')] were used for RAPD. None of the isolates had high minimal inhibitory concentration (MIC) values (>1 mug ml(-1)) against amphotericin B with MIC(50)values of 0.5 mug ml(-1), 0.5 mug ml(-1) and 0.125 mug ml(-1) for C. albicans, C. tropicalis and C. glabrata isolates, respectively. However, three C. glabrata isolates were resistant and one C. albicans and five C. glabrata isolates were dose-dependent susceptible (D-DS) to fluconazole. Among C. albicans isolates 19 and 20 patterns were detected with primers Cnd3 and Cnd4, respectively. When primers Cnd3 and Cnd4 were evaluated together, three and four genotypes were identified for C. tropicalis and C. glabrata isolates, respectively. Our results suggest that the source of C. albicans isolates was mostly endogenous. It is difficult to interpret the mode of spread of C. tropicalis and C. glabrata urine isolates as we obtained insufficient banding patterns for these species

The effects of macrolide agents on nitric oxide production

The effects of two macrolides which are known to accumulate in macrophages, namely azithromycin (AZM) and erythromycin (ERM), on in vitro nitric oxide (NO) synthesis by lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages were examined. AZM and ERM were added to peritoneal macrophage cultures (1 x 10(5) adherent cell/well) at concentrations 0.5, 10 and 50 mu g/ml, 1 and 4 days prior to LPS stimulation, NO response was measured by nitrite production. When compared to the control wells, nitrite accumulation after LPS stimulation (1 mu g/ml) decreased by 39.8% (p0.05), 3.5% (p>0.05) in the presence of 50, 10 and 0.5 mu g/mls of AZM, respectively. ERM decreased nitrite accumulation only minimally. Our results indicate that, in this murine peritoneal macrophage model, azithromycin but not erythromycin can alter NO response significantly

Modulation of nitric oxide response by fluoroquinolones

In this study, we examined the effects of fluoroqinolones, namely ciprofloxacin (CIP) and ofloxacin (OFX) on nitric oxide (NO) production in an in vitro lipopolysaccharide(LPS)-activated macrophage model. Thioglycollate-elicited;ed peritoneal cells from BALB/c mice were exposed to varying concentrations of CIP and OFX for 1 or 4 days before LPS stimulation. NO response was measured by nitrite accumulation. On the first day of antibiotic exposure, nitrite production after LPS stimulation (1 mu g/ml) decreased by 49.3% (p0.05) and by 29.7% (p0.05) in the presence of 1 mM, 100 mu M and 10 mu M CIP and OFX, respectively. The inhibitory effects did not change significantly after 4 days' of exposure. The results indicate that, in this in vitro murine macrophage model, fluoroquinolones inhibit nitrite production in a dose-dependent manner and may have similar immunomodulatory effects in vivo