Properties and characterization of ALD grown dielectric oxides for MIS structures

We report on an extensive structural and electrical characterization of under-gate dielectric oxide insulators Al2O3 and HfO2 grown by Atomic Layer Deposition (ALD). We elaborate the ALD growth window for these oxides, finding that the 40-100 nm thick layers of both oxides exhibit fine surface flatness and required amorphous structure. These layers constitute a base for further metallic gate evaporation to complete the Metal-Insulator-Semiconductor structure. Our best devices survive energizing up to ~3 MV/cm at 77 K with the leakage current staying below the state-of-the-art level of 1 nA. At these conditions the displaced charge corresponds to a change of the sheet carrier density of 3 \times 1013 cm-2, what promises an effective modulation of the micromagnetic properties in diluted ferromagnetic semiconductors.Comment: 8 pages, 5 figures, 14 reference

Characteristics of hereditary ovarian cancer

Ovarian cancer is the fifth major cause of cancer-related mortality among women. In Wielkopolska, higher incidence and mortality rates are observed compared to other regions of Poland. Ovarian cancer affects mainly women in their sixties and seventies. The etiology of this disease has not been fully understood yet. The factors contributing to increased risk of ovarian cancer occurrence include infertility, breast cancer diagnosed before the age of 45 and family history of ovarian cancer while childbearing and oral contraceptives are considered to be protective factors.Simultaneous genetic and epidemiological studies based on analyzing pedigrees of families with multiple cases of ovarian cancer and indicate a role of the genetic factor in ovarian cancer etiology. Familial forms of ovarian cancer which represent approximately 5–10% of all cases are associated with certain syndromes, including: familial breast and ovarian cancer syndrome related to mutations in BRCA1, familial breast cancer syndrome related to mutations in BRCA2 which can be accompanied by ovarian cancer, Lynch II syndrome characterized by the occurrence of ovarian cancer, colon cancer and endometrial cancer in the family as well as the syndrome of hereditary non-polypous colon cancer (HNPCC). Genetic ovarian cancer is most often diagnosed before the age of fifty.Identification of individuals with a high risk of genetic predisposition to developing ovarian cancer should be based on precise information collected during interviews with family members complemented by the data on personal risk factors. Women identified as members of high-risk groups can be offered genetic testing aimed at detecting asymptomatic carriers of mutations in genes predisposing to ovarian cancer.On the one hand, genetic tests represent a new, extremely powerful instrument for identifying individuals genetically predisposed to ovarian cancer, on the other hand, however, they create numerous problems. The two basic controversies which need clarifying are: who should be offered genetic testing and what preventive measures can be taken to help women carrying gene mutations increasing the risk of developing cancer, including ovarian cancer. Most issues related to genetic types of cancer (including ovarian) require further investigation and studies and currently proposed protocols are still widely discussed

The role of p53 gene in lung cancer with special emphasis on hereditary types

Lung cancer is the most common type of cancer affecting men and the fifth most frequent female cancer. The survival rate related to lung cancer is low, with the 5-year survival amounting to 10–13% in highly advanced countries. In Poland lung cancer survival does not exceed 5%.The major causes of lung cancer incidence include tobacco smoking, environmental factors and genetic predisposition. The most frequent genetic modifications observed in lung cancer cells are mutations in the myc, ras and/or erb1 genes.The p53 gene has been located on the short arm of chromosome 17 and has been found to consist of 11 exons with the first one being non-coding. The analysis of its sequence in different species resulted in identifying five highly conservative regions, including exons 1, 4, 5, 7 and 8. The p53 has been classified as a suppresser gene.The p53 protein is a nuclear phosphoprotein composed of 393 amino-acids. This protein is active in the two most important stages of the cellular cycle: during the transition between phases G1 and S and between phases G2 and M. The function of p53 can be described as ensuring the integrity of the genome by preventing replication of the damaged DNA and cell division. When the repair process fails, p53 triggers the apoptosis of cells. In addition to the regulatory function, p53 acts also as a transcription agent.Mutations in p53 are responsible for 60% of cases of human lung cancer. The mutations are most often found in microcellular lung cancer (70%) and are less frequent in the cases of adenoid lung cancer (33%). The most common mutations related to lung cancers include: transversions of the G:C/A:T type, missense mutations, nonsense mutations and deletions. These mutations occur in as many as 100 various locations but the most characteristic ones for lung cancer are found in codon 157, 248 and 273. The hereditary mutations in p53 are associated with the Li-Fraumeni syndrome. This syndrome indicates a higher risk of developing different forms of cancer, including lung cancer. Genetic testing aimed at identifying the carriers of p53 mutations should be limited only to high-risk groups defined on the basis of a diagnostic pattern proposed by Lynch. In the families with one member affected by lung cancer the risk of developing lung cancer by first-degree relatives is four times higher compared to general population risk

Numerical simulation of strongly nonlinear and dispersive waves using a Green-Naghdi model

We investigate here the ability of a Green-Naghdi model to reproduce strongly nonlinear and dispersive wave propagation. We test in particular the behavior of the new hybrid finite-volume and finite-difference splitting approach recently developed by the authors and collaborators on the challenging benchmark of waves propagating over a submerged bar. Such a configuration requires a model with very good dispersive properties, because of the high-order harmonics generated by topography-induced nonlinear interactions. We thus depart from the aforementioned work and choose to use a new Green-Naghdi system with improved frequency dispersion characteristics. The absence of dry areas also allows us to improve the treatment of the hyperbolic part of the equations. This leads to very satisfying results for the demanding benchmarks under consideration

A Combine On-Line Acoustic Flowmeter and Fluorocarbon Coolant Mixture Analyzer for The ATLAS Silicon Tracker

An upgrade to the ATLAS silicon tracker cooling control system may require a change from C3F8 (octafluoro-propane) to a blend containing 10-30% of C2F6 (hexafluoro-ethane) to reduce the evaporation temperature and better protect the silicon from cumulative radiation damage with increasing LHC luminosity. Central to this upgrade is a new acoustic instrument for the real-time measurement of the C3F8/C2F6 mixture ratio and flow. The instrument and its Supervisory, Control and Data Acquisition (SCADA) software are described in this paper. The instrument has demonstrated a resolution of 3.10-3 for C3F8/C2F6 mixtures with ~20%C2F6, and flow resolution of 2% of full scale for mass flows up to 30gs-1. In mixtures of widely-differing molecular weight (mw), higher mixture precision is possible: a sensitivity of < 5.10-4 to leaks of C3F8 into the ATLAS pixel detector nitrogen envelope (mw difference 160) has been seen. The instrument has many potential applications, including the analysis of mixtures of hydrocarbons, vapours for semi-conductor manufacture and anaesthesia