Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Nanotechnology ; 27(11): 115304, 2016 Mar 18.
Article in English | MEDLINE | ID: mdl-26878568

ABSTRACT

Electron-beam-induced deposition of titanium oxide nanopatterns is described. The precursor is titanium tetra-isopropoxide, delivered to the deposition point through a needle and mixed with oxygen at the same point via a flow through a separate needle. The depositions are free of residual carbon and have an EDX determined stoichiometry of TiO2.2. High resolution transmission electron microscopy and Raman spectroscopy studies reveal an amorphous structure of the fabricated titanium oxide. Ellipsometric characterization of the deposited material reveals a refractive index of 2.2-2.4 RIU in the spectral range of 500-1700 nm and a very low extinction coefficient (lower than 10(-6) in the range of 400-1700 nm), which is consistent with high quality titanium oxide. The electrical resistivity of the titanium oxide patterned with this new process is in the range of 10-40 GΩ cm and the measured breakdown field is in the range of 10-70 V µm(-1). The fabricated nanopatterns are important for a variety of applications, including field-effect transistors, memory devices, MEMS, waveguide structures, bio- and chemical sensors.

2.
Nanotechnology ; 25(15): 155301, 2014 Apr 18.
Article in English | MEDLINE | ID: mdl-24642787

ABSTRACT

An oxygen-assisted electron-beam-induced deposition (EBID) process, in which an oxygen flow and the vapor phase of the precursor, tetraethyl orthosilicate (TEOS), are both mixed and delivered through a single needle, is described. The optical properties of the SiO(2+δ) (- 0.04 ≤ δ ≤ +0.28) are comparable to fused silica. The electrical resistivity of both single-needle and double-needle SiO(2+δ) are comparable (greater than 7 GΩ cm) and a measured breakdown field is greater than 400 V µm(-1). Compared to the double-needle process the advantage of the single-needle technique is the ease of alignment and the proximity to the deposition location, which facilitates fabrication of complex 3D structures for nanophotonics, photovoltaics, micro- and nano-electronics applications.

3.
Oncology ; 51(4): 329-33, 1994.
Article in English | MEDLINE | ID: mdl-8208515

ABSTRACT

Cathepsin D is an acidic lysosomal protease expressed in all cells. Some studies have shown correlations between high levels of tissue cathepsin D and poor prognosis. This paper deals with 158 cases of breast cancer in which tissue concentrations in cathepsin D, age, estrogen and progesterone receptor content, and pathological characteristics of the tumor were investigated. Tumors were considered to be cathepsin D+ when a concentration > 40 pmol/mg protein (median value in our samples) was determined. The expression of cathepsin D appears to be related to grading (p = 0.04) and lymph node status (p = 0.05). We found no significant associations among cathepsin D levels, patient age, steroid receptors and histological type. Moreover, the levels of cathepsin D have been evaluated in 9 samples of recurring or metastatic neoplasia and 11 cases of benign breast lesions. We conclude that cathepsin D may be a useful prognostic predictor in breast cancer. Further investigations are required to improve and extend the applications of this assay.


Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/enzymology , Cathepsin D/analysis , Breast Neoplasms/pathology , Female , Humans , Lymphatic Metastasis , Middle Aged , Prognosis
4.
Cancer Detect Prev ; 17(3): 411-5, 1993.
Article in English | MEDLINE | ID: mdl-8402728

ABSTRACT

With the aim of investigating the clinical usefulness of CEA, CA 15-3, and MCA serum levels, we studied 143 women whose breast cancer was submitted to serial tumor marker determinations: 79 women had stage I-II tumors and were undergoing follow-up after local and adjuvant treatment; 64 women presented metastatic lesions. Among the stage I-II patients, 63 women remained disease-free during the observation period and 16 developed metastases. In 13 out of 16 patients, tumor markers were elevated and in 11 out of 16 patients the increased tumor markers were the first sign of disease progression. Among metastatic patients, 49 presented increased tumor markers and 15 normal value. Moreover, we observed a decrease or normalization of tumor markers in patients responding to treatment and increased values in progressive disease. No correlation was noted between site of disease and tumor markers. We concluded that tumor markers are of clinical value in the detection of metastasis and may be useful in monitoring response to treatment in metastatic patients.


Subject(s)
Antigens, Neoplasm/blood , Antigens, Tumor-Associated, Carbohydrate/blood , Biomarkers, Tumor/blood , Breast Neoplasms/blood , Carcinoembryonic Antigen/blood , Carcinoma/blood , Adult , Aged , Breast Neoplasms/immunology , Carcinoma/immunology , Carcinoma/secondary , Female , Humans , Middle Aged
SELECTION OF CITATIONS
SEARCH DETAIL
...