Cadmium zinc telluride, CdZnTe or CZT, is presently the best candidate for radiation detectors since it can operate at room temperature and in hostile environment. In recent years, advancements of ...the crystal growth methods and subsequent processes, as for example thermal treatments, have led to an increasing quality of the material. However, the major obstacle to optimize detectors' performance still consists in the defects, both grown-in and processing-induced, which seem to be inevitably present. In this contribution, we present the state-of-the-art of the knowledge on the electrical properties of defects in Cd(1−x)ZnxTe with zinc content x=0.1–0.2, focusing on point defects due to intrinsic defects or their complexes.
•We shortly review the state-of-the-art knowledge on the electrical properties of point defects in CZT.•Electronic levels associated with point defects in cadmium zinc telluride.•Point defects.
This paper deals with partial discharge (PD) measurements on inverter-fed motors. They are performed by means of a broadband sensor-filter system that allows PD signal to be recorded, damping the ...noise generated by the commutation interference of electronic power supply. In this way, online or offline measurements can be carried out with the purpose of evaluating the presence of PDs in adjustable speed drives, which often constitute the main cause of winding insulation degradation and premature breakdown. An offline testing technique is also proposed to offer an insight into PD activity and a more precise location of PD sources. These techniques can allow improved quality control and diagnostics on power-electronic-controlled motors.
Applications of a new methodology, aimed at the identification of defects occurring in insulation systems of HV apparatus and based on partial discharge (PD) measurements, are presented in this ...paper. This methodology relies upon the digital acquisition of a large amount of PD pulses and separates the acquired pulses into homogeneous subclasses. Signal processing tools recognize the presence of noise among the different classes. Identification of basic PD source typologies (i.e., internal, corona and surface discharges) is then achieved, resorting to fuzzy algorithms. The proposed procedure is applied to measurements performed on different HV apparatus, such as cables, transformers and rotating machines. The purpose of this paper is to show that the identification process is robust, regarding the measuring circuit, and flexible, so that it can constitute an advanced tool for condition based maintenance, guiding maintenance experts in making decisions on the condition of the insulation system under test.
Aim The treatment of desmoid tumours (DTs) is controversial. Anti‐oestrogen therapy has frequently been used, but clear information of its efficacy is lacking. In this systematic review we have ...undertaken a comprehensive analysis to assess the effectiveness of anti‐oestrogen therapy in terms of ability to induce partial or complete regression of DTs.
Method A systematic review of articles published in English between January 1983 and December 2009 was carried out according to the RECIST criteria. A literature search was performed on electronic databases including: United States National Library of Medicine (MEDLINE‐PubMed), Excerpta Medica (EMBASE), Cochrane Library and Google search engine. Two‐hundred articles dealing with DTs were identified but only fourty‐one were were selected as appropriate for the study. The chi‐square test was used for statistical analysis.
Results Data on 168 DTs treated with anti‐oestrogen agents, alone or in combination with nonsteroidal anti‐inflammatory drugs, were identified with an overall response rate of 51%. There was no difference in response according to the type of DTs or between different anti‐oestrogen therapies. Combination with anti‐inflammatory drugs did not improve the outcome. Toremifene was sometimes effective in cases resistant to tamoxifen. Response did not seem to be related to oestrogen receptor status.
Conclusions Despite potential inaccuracies in the methodology, the results of the review indicate that anti‐oestrogen therapy produces some effect in about one half of patients with DTs. Its indication compared with other treatments is discussed.
Purpose
The purpose of this study was to explore the potential role of deranged fecal microRNA (miRNA) pattern as a reliable warning signal of colorectal cancer (CRC), a subset of fecal CRC-related ...miRNAs was evaluated in CRC patients, before and after surgery, and in healthy controls.
Methods
Twenty CRC patients and 20 age/sex-matched healthy volunteers with negative colonoscopy entered the study. Cancer biopsy, colonic mucosa from the resected specimens, and fecal samples from patients and controls were screened for 13 miRNAs involved in CRC onset and progressions by reverse transcription quantitative PCR (RT-qPCR). Postoperative evaluation of fecal miRNAs was carried out after a median follow-up of 18 months (range 12–30).
Results
Two out 13 miRNAs (
RNU6B
,
miR-16-3p
) were used as internal controls leaving 11 available for analysis. Cancer tissue contained significantly higher expression of all miRNAs, compared to normal mucosa (
p
< 0.05). Expression of preoperative levels of five fecal miRNAs, (
miR-19-b-3p, miR-20a-5p, miR-21-3p, miR92a-3p, miR141
) was significantly higher in CRC patients compared to controls and significantly decreased after curative surgery. Three out of these five miRNAs (
miR20a-5p, miR21-3p
, and
miR141
) returned to values comparable to normal controls.
Conclusions
A set of three specific fecal miRNAs is overexpressed before surgery, and return within the normal range after cancer removal could be considered as an appealing opportunity for a new reliable tool for CRC secondary prevention. However, their role needs to be explored in large prospective trials and compared with the existing screening tools.
The purpose of this paper is to understand the pros and cons of aluminum conductors insulated with anodized aluminum for rotating machines used in aircraft. The investigation is focused on the ...breakdown voltage and partial discharge inception voltage of simple systems (crossed pairs, simplified coils). The results show that both breakdown voltage and partial discharge inception voltage are very sensitive to curvature radius and lower than those achieved using conventional copper conductors insulated with polymeric enamels. However, the operating temperature of the insulation (600 °C) is extremely appealing. Therefore, it could be interesting to devise high temperature fillers and suitable manufacturing procedures to exploit this insulation system in specific applications, where the weight of the machine is the key factor for material selection.
Surface photovoltage spectroscopy and spectral photoconductivity measurements have been carried out in the UV spectral region on GaN nanowires to analyze the near band-edge region. The results reveal ...the presence of tails in the band−band absorption spectra. Surface Photovoltage spectra performed on the as-grown nanowire ensamble show a long band tail of about 0.1 eV. Spectral photoconductivity on singly contacted nanowires shows that the band tail width strictly depends on the wire diameter. These results are explained by the Franz−Keldysh effect due to the internal electric field induced by Fermi level pinning at the nanowire surface. The experimental values of the absorption tail are well in agreement with the results obtained by simulating the electric field in a cylindrical model.
A novel method to diagnose PWM-fed induction motors Cavallini, A.; Fabiani, D.; Montanari, G.C.
IEEE transactions on dielectrics and electrical insulation,
10/2008, Letnik:
15, Številka:
5
Journal Article
Recenzirano
A novel method for measurement and interpretation of PD phenomena in inverter-fed motors is discussed in this paper. The interpretation of PD measurements is carried out resorting to the ...direct-quadrature (dq) transform of the three voltages at motor terminals at the instant a PD event occurs. New tools (the dq loci, dq Hq and dq Hn patterns) are proposed to infer PD activity in a statistical way, similar to that used under AC supply. The method has been validated through tests on motorettes. In addition, measurements on low-voltage inverter-fed motors subjected to repetitive surges till breakdown are reported to support the capability of the method to infer onsetting faults. Measurements are performed through a reliable and lightweight (thus suitable for, e.g., automotive or avionics applications) antenna coupler characterized by excellent signal-to-nose ratio.
Endovenous laser treatment (EVLT) is an accepted form of axial vein ablation for symptomatic venous reflux but its role in the treatment of anterior accessory saphenous vein (AASV) has not been well ...characterized. The aim of this paper is to show the short-term result of EVLT with a ball-tipped fiber and a 1540 nm diode laser of the AASV with preservation of a competent great saphenous vein (GSV).
Nine incompetent AASV veins in 8 patients (6 female) were treated. The gravity of chronic venous disease was determined according to the CEAP classification and the severity of symptoms was scored according to the revised Venous Clinical Severity Score. Patient satisfaction was assessed by a 0 to 3 scale.
The average linear endovenous energy density was 60.5 J/cm vein (SD: 7.5). Patients returned to daily activities after a mean of 3.8 days (SD: 1.4). 5 patients (63%) have had pain but of mild intensity. No patients developed paresthesia or phlebitis reactions in the treated area. Post-operative ecchymoses are frequent (89%). During the follow-up period (mean 13 months, range: 7-17 months) all the veins were occluded. The VCSS improved drastically from a mean of 3.2 (SD: 1.3) preinterventional to 0 (SD: 0.38) at 17 months. All patients were satisfied or very satisfied with the method. No severe complications occurred.
EVLT of an incompetent AASV with a 1540 nm diode laser is a safe and efficient therapy option, with a high success rate and with no evidence of GSV neo-reflux or recurrent varicosities during the follow-up period.
