Investigation of growth temperature effects on SnSe-based photodetector performance

SnSe thin films were synthesized by thermal evaporation on glass slides at elevated growth temperatures. The grown films were investigated in terms of structural, morphological and optical properties. Furthermore, electrical characteristics and time-dependent photoresponses of SnSe-based photodetectors were studied in depth. SnSe thin films showed orthorhombic crystal structure with a preferred orientation of (400) for the growth temperature of 150 & DEG;C. However, the preferential orientation changed from (400) to (111) with increasing of growth temperature to 200 & DEG;C. Top view SEM data displayed a porous morphology for the samples grown at 200 & DEG;C and 250 & DEG;C temperatures. More transparent SnSe films were obtained when the growth temperature was increased to 200 & DEG;C. The band gaps of SnSe sample deposited at 150 & DEG;C and 200 & DEG;C were determined to be 1.22 eV. However, band gap reduces to 1.06 eV with the increase of the substrate temperature to 250 & DEG;C. Raman data demonstrated the shift in the general peak positions to higher frequencies as the growth temperature is increased due to the variation in bond lengths between Sn and Se atoms. Photocurrent-time data showed that SnSe sample grown at a growth temperature of 200 & DEG;C possessed the highest photocurrents because of the formation of porous structure. Rise and fall times of SnSe-based photodetector decay systematically with increasing growth temperature and the maximum responsivity and detectivity were found to be 3.33 x 10-1 A/W and 2.03 x 107 Jones, respectively for the device employing the film deposited at 200 & DEG;C

Improved CZTSe solar cell efficiency via silver and germanium alloying

In this study, we report systematic investigation of the effects of Ag and Ge alloying on properties of CZTSe layers, as well as, on the performance of solar cells fabricated using these films. In this context, Ag-Ge doped CZTSe layers were produced by selenization of Cu/Sn/Zn/Cu/(Ag,Ge)/Se precursor stack structures using rapid thermal processing. All precursor stacks and the Ag-Ge doped CZTSe films obtained after selenization exhibited (Cu + Ag)-poor and Zn-rich chemical composition. XRD studies demonstrated pure kesterite phase for all reacted films. Raman spectra confirmed this finding. Cross-sectional SEMs showed large grain structure, which resulted from Ag-Se and Ge-Se liquid phase formation that assisted crystal growth during high temperature annealing. While a slight Ag-front-gradient was achieved in Ag-doped CZTSe film, the Ag gradient disappeared with incorporation of Ge into the lattice. Addition of Ge formed a gradient within the material such that near-contact region was more Ge-rich. Solar cells fabricated using films with various compositions demonstrated that double doping CZTSe with both Ag and Ge improved the device efficiency from about 5 % to over 8 %.Scientific and Technological Research Council of Turkiye [120F029]This study is financially supported by the Scientific and Technological Research Council of Turkiye with the project number of 120F029

Automated white matter fiber tract identification in patients with brain tumors

We propose a method for the automated identification of key white matter fiber tracts for neurosurgical planning, and we apply the method in a retrospective study of 18 consecutive neurosurgical patients with brain tumors. Our method is designed to be relatively robust to challenges in neurosurgical tractography, which include peritumoral edema, displacement, and mass effect caused by mass lesions. The proposed method has two parts. First, we learn a data-driven white matter parcellation or fiber cluster atlas using groupwise registration and spectral clustering of multi-fiber tractography from healthy controls. Key fiber tract clusters are identified in the atlas. Next, patient-specific fiber tracts are automatically identified using tractography-based registration to the atlas and spectral embedding of patient tractography. Results indicate good generalization of the data-driven atlas to patients: 80% of the 800 fiber clusters were identified in all 18 patients, and 94% of the 800 fiber clusters were found in 16 or more of the 18 patients. Automated subject-specific tract identification was evaluated by quantitative comparison to subject-specific motor and language functional MRI, focusing on the arcuate fasciculus (language) and corticospinal tracts (motor), which were identified in all patients. Results indicate good colocalization: 89 of 95, or 94%, of patient-specific language and motor activations were intersected by the corresponding identified tract. All patient-specific activations were within 3mm of the corresponding language or motor tract. Overall, our results indicate the potential of an automated method for identifying fiber tracts of interest for neurosurgical planning, even in patients with mass lesions

Investigating the effectiveness of different tea types from various thyme kinds (Origanum onites, Thymbra spicata and Satureja cuneifolia) on anemia and anticholesterolemic activity

PMID = 2318865

entity

Some primary carcinomas of the breast have been classified as neuroendocrine. In this paper we report on 12 cases of neuroendocrine carcinoma of the breast displaying common and uncommon histological features.Materials and methods: All patients were aged from 43 to 79 (median 66.5) years. The tumors were unilateral and ranged from 0.8 to 7 cm (median 2.35 cm) in diameter. Four tumors were classified as solid cohesive, two as solid papillary, one as Merkel cell-like, two as cellular mucinous, two as cellular mucinous with micropapillary features and one as cellular mucinous with prominent signet ring cells. The tissues were fixed in formalin and routinely processed. All materials were stained with PAS, Alcian blue and also hematoxylin and eosin. Immunohistochemical examination was carried out by the avidin-biotin method using the following antibodies: estrogen receptor protein, progesterone receptor protein, p53, cerbB-2, Ki67, neuron-specific enolase, chromogranin, and synaptophysin.Results: In all cases the tumor cells were stained positively with NSE. Synaptophysin and chromogranin positivity was detected in I I and five cases, respectively. The prominent histological features were: extensive intraductal growth, pseudorosettes and palisades, low-grade cytologic atypia, plasmacytoid appearance of the tumor cells, and intracellular and extracellular mucin.Conclusion: Neuroendocrine-differentiated carcinoma of the breast is a rare and distinct category with different histological subtypes. (C) 2003 Elsevier Science Ltd. All rights reserved

Inhibin alpha and beta expression in ovarian stromal tumors and their histological equivalences

WOS: 000221059400015PubMed ID: 15059165Inhibin is a heterodimeric protein hormone that appears to be a sensitive immunohistochemical marker of sex cord-stromal tumors. Although sex cord-stromal tumors can usually be distinguished from ovarian epithelial tumors or their metastases by morphology or by using antibodies against intermediate filaments, the diagnosis remains difficult in rare situations in such cases as sarcomatoid granulosa-theca cell tumors, ovarian small cell carcinomas, or soft-tissue sarcomas. The purposes of this study were to examine inhibin alpha and beta immunoreactivity in a wide range of gonadal stromal neoplasms and to assess its value in the differential diagnosis of problematic tumors. A total of 108 paraffin-embedded ovarian and extraovarian tumors were examined immunohistochemically by using anti-alpha inhibin and anti-beta inhibin. Inhibin alpha immunostaining was identified in 46(81%) of 57 gonadal stromal tumors, one(14%) of seven endometrial stromal tumors, and one(50%) of two primary ovarian carcinoid tumors. Inhibin beta immunostaining was detected in 55(96%) of 57 gonadal stromal tumors, two(29%) of seven endometrial stromal tumors, one(50%) of two dysgerminomas, and in all of two (100%) primary ovarian carcinoid tumors. Inhibin alpha expression was not detected in any ovarian surface epithelial tumor cells. Some surface epithelial tumors showed stromal inhibin alpha (15% of cases) and inhibin beta (48% of cases) positivity. Weak immunoreactivity for inhibin beta was found in most (83% of cases) ovarian surface epithelial tumors. Two ovarian Burkitt lymphomas were negative for inhibin alpha and beta. Inhibin alpha is a sensitive immunohistochemical marker of gonadal stromal tumors and is of value in the differential diagnosis of ovarian neoplasia. Inhibin beta is a nonspecific marker for ovarian neoplasms, showing expression on tumor and stromal cells of different epithelial or stromal tumors

Aplastic anemia, mucormycosis and aspergillosis in infectious mononucleosis: Success is possible

Infectious mononucleosis (IM) is a rare cause of aplastic anemia in adults. We report of a patient in whom aplastic anemia, mucormycosis and aspergillosis complicated during the course of IM and successfully treated with liposomal amphotericin B. According to our searches in literature, we could not find a similar patient complicated and successfully treated like ours. (C) 2007 Elsevier Ltd. All rights reserved

Do Clinical and Immunohistochemical Findings of Pure Mucinous Breast Carcinoma Differ from Mixed Mucinous Breast Carcinoma ?

WOS: 000266210100011PubMed ID: 19499682Mucinous carcinoma of the breast is a relatively rare histologic type with two subtypes : pure and mixed. It has a favourable prognosis with a low risk of axillary metastases. The prognosis for pure mucinous carcinoma (PMC) was much better than for the mixed mucinous carcinoma (MMC). The aim of the study is to determine suitable candidates for breast or axillary conservation in mucinous carcinoma subtypes. The slides of 26 pure and 23 mixed mucinous carcinomas of the breast were evaluated. The clinical, pathological and immunohistochemical features between PMCs and MMCs were compared. MMC displayed greater metastatic potential (p < 0.05), p53 positivity (p < 0.05) and c-erbB-2 positivity (p < 0.001) than PMCs. PMCs smaller than 2 cm had less metastatic capacity and extranodal invasion compared to MMCs smaller than 2 cm (p < 0.001 and p < 0.01, respectively). MMCs smaller than 2 cm displayed weaker ER positivity but greater c-erbB-2 positivity than PMCs smaller than 2 cm (p < 0.01). In conclusion, MMC had worse prognostic factors than PMC with both types of mucinous carcinoma showing similar ER and PR positive status. Even if PMCs and especially smaller PMCs display more favourable prognostic features, including less axillary lymph node involvement, it is appropriate to use sentinel lymph node biopsy to make better axillary assessment

Breast carcinomas with choriocarcinomatous features: Case reports and review of the literature

PubMed ID: 12100118Breast cancer with choriocarcinomatous features is rare. This report describes four cases of breast cancer with choriocarcinomatous features. The tumor cells were positive for human placental lactogen (hPL) and human chorionic gonadotropin (hCG) by immunohistochemistry. The cases reported in the literature had a poor prognosis and the patients died within a few months after the diagnosis. In this series, two cases were lost to follow-up, but the other two have had disease-free survival for 2 and 4 years, respectively