1,035 research outputs found
Characterisation of Hybrid Pixel Detectors with capacitive charge division
In order to fully exploit the physics potential of the future high energy e+
e- linear collider, a Vertex Tracker providing high resolution track
reconstruction is required. Hybrid pixel sensors are an attractive technology
due to their fast read-out capabilities and radiation hardness. A novel pixel
detector layout with interleaved cells between the readout nodes has been
developed to improve the single point resolution. The results of the
characterisation of the first processed prototypes are reported.Comment: 5 pages, 2 figures, presented at LCWS2000, Linear Collider Workshop,
October 24-28 2000, Fermi National Accelerator Laboratory, Batavia, Illinois,
U.S.A. Proceedings to be published by the American Institute of Physic
Fatty foci within the heart and the accompanying changes in the coronary arteries diagnosed in electrocardiogram-gated multislice computed tomography of the heart
Background: The purpose of our study was to analyse the relationship between fatty foci within the heart and the accompanying changes in the coronary arteries supplying the relevant heart chambers in a large group of patients referred to multi-slice computed tomography with electrocardiogram-gating examinations (ECG-MSCT) for various clinical reasons. Materials and methods: The ECG-MSCT examinations of 1,830 consecutive patients were analysed. The examinations were performed using 8-row (1,015 patients) and 64-row (815 patients) MSCT, in pre- and postcontrast scanning. In the group of patients with fatty foci within the heart the concomitant changes in the coronary arteries were assessed. It was analysed: the type of changes in the arteries; the relationship between the locations of the fatty deposits and the occurrence and type of changes in the coronary arteries. Results: In 200 (10.9%) subjects fatty foci within the heart (112 men; 88 women; mean age 57.8) were detected. The distribution of the fat was as follows: right ventricle (RV) — 32.5%, left ventricle (LV) — 22.0%, biventricular — 45.5%. One hundred and seventy-two patients had concomitant changes in the coronary arteries. In patients with normal coronary arteries, significantly more often fatty deposits were localised within RV. Fat was primarily located subendocardially in the LV in patients with atherosclerosis in the left anterior descending artery (p < 0.001), in the right coronary artery (RCA) (p = 0.003), and in the left circumflex artery (LCX) (p < 0.001). Subpericardial locations of fatty deposits in RV significantly correlated with RCA bridging (p < 0.02); the subpericardial location of fat in LV significantly correlated with LCX bridging (p = 0.001). Conclusions: Fatty replacement of the myocardium is common, occurring in up to 10% of diagnosed patients and the majority of this group had concomitant changes in the coronary arteries. However, in the group of patients without changes in the coronary arteries, the fatty deposits locate themselves significantly more frequently within the RV
A Pixel Vertex Tracker for the TESLA Detector
In order to fully exploit the physics potential of a e+e- linear collider,
such as TESLA, a Vertex Tracker providing high resolution track reconstruction
is required. Hybrid Silicon pixel sensors are an attractive sensor technology
option due to their read-out speed and radiation hardness, favoured in the high
rate TESLA environment, but have been so far limited by the achievable single
point space resolution. A novel layout of pixel detectors with interleaved
cells to improve their spatial resolution is introduced and the results of the
characterisation of a first set of test structures are discussed. In this note,
a conceptual design of the TESLA Vertex Tracker, based on hybrid pixel sensors
is presentedComment: 20 pages, 11 figure
ECG-gated multi-slice computed tomography in the detection of atrial septal aneurysms
An atrial septal aneurysm (ASA) is an uncommon cardiac abnormality. Clinical
manifestation of this abnormality remains unclear: some authors have suggested
an association between ASA and arrhythmias or between ASA and cerebral
ischaemia. A major role in the diagnosis of ASA to date has been played
by transoesophageal echocardiography and transthoracic echocardiography.
The purpose of this paper is to present the role of multi-slice computed tomography
with ECG gating in the detection and analysis of ASA. (Folia Morphol
2008; 67: 126–128
Ecophysiology and dynamics of nitrogen removal bacteria in a sequencing batch reactor during wastewater treatment start‑up
Nitrogen removal communities performing wastewater treatment consist of ammonia oxidisers, nitrite oxidisers, denitrifiers,
and anammox bacteria, and the proportion and activity of particular microbial groups depend not only on the physiochemical
parameters of the bioreactor, but also on the composition of the inoculum. Nitrifiers and denitrifiers usually dominate
in conventional wastewater treatment systems due to the fact that nitrification and denitrification are the most commonly
used nitrogen removal processes. However, from the economical point of view in case of wastewater with high ammonia
concentrations, anammox-based technologies are desirable for their treatment. The disadvantage of such systems is slow
anammox bacteria growth, which extends an effective technological start-up. Thus, in this study, a fast start-up of the anammox
process supported with an anammox-rich inoculum was performed in a sequencing batch reactor (SBR). Using anammox
inoculation of SBR laboratory system, the start-up can be fastened to 85 days with 84.5% of nitrogen removal efficacy.
The spatial distribution of nitrogen removal bacteria analysed with fluorescent in situ hybridisation revealed that anammox
and nitrifiers are located side by side in the flocs and the relative number of ammonia and nitrite oxidisers decreased after
85 days of the experiment
Anatomic variability of groin innervation
Inguinal hernia repairs are very common yet fairly complex surgical procedures.Variations in the anatomical course of the inguinal nerves require that diligenceis taken in their proper recognition. Inadvertent surgical injury to these nerves isassociated with long term postoperative pain and complications. The aim of thepresent study was to highlight the complexity and variation in the innervation ofthe inguinal region in order to increase proper nerve identification during surgicalinterventions. Bilateral dissection of the inguinal and posterior abdominal regionsin one human male cadaver revealed an atypical anatomic topography of thegroin innervation. This unusual case was observed at the Jagiellonian UniversityAnatomy Department during routine cadaveric preparations. The left ilioinguinalnerve was absent. The left genital branch of the genitofemoral nerve arose higherthan expected from the lumbar plexus and supplied the groin region, which istypically innervated by the ilioinguinal nerve. Furthermore, the left lateral cutaneousfemoral nerve and the right genital branch of the genitofemoral nerve alsofollowed uncharacteristic courses. Awareness of topographical nerve variationsduring inguinal hernia repair will help surgeons identify and preserve importantnerves, thus decreasing the incidence of chronic postoperative pain
Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population
The aim of the study was to investigate the distribution of the circle of Willis variants in Polish population by means of computed tomography angiography (CTA). The results were then analysed and compared with another study that used similar methods but that was carried out on an ethnically distinct population. Patients presenting with intracranial pathology were excluded from the initial study population. In total, 250 CTA belonging to 129 female and 121 male patients were reviewed. A modified classification system of the circle was proposed, which took into consideration the anterior and the posterior aspects of the circle individually. The typical variant of Willis’s circle occurred in 16.80% of cases. The anterior and the posterior portions of the circle were normal in 47.20% and 26.80% of the patients respectively. As forthe anterior part, lack of the anterior communicating artery was the most frequent abnormality (22.80%). Bilateral absence of posterior communicating arteries was the most common anomaly in the posterior part of the circle (29.20%). This type of anomaly was also the most common, when taking into consideration the entire circle (12.00%). There were statistically significant differences between the age groupsand genders when considering the occurrence of an incomplete circle. Overall, a substantial proportion of patients manifested clinically important variants that were incapable of providing collateral circulation. Comparison with other imaging-based and cadaveric studies revealed noticeable differences, that may have resulted from the variable technical features of other studies or other factors such as the ethnical origins of the studied populations
Coronary artery fistulas morphology in coronary computed tomography angiography
Background: The aim of the study was to evaluate coronary artery fistulas (CAFs) in coronary computed tomography angiography (coronary CTA) and verify whether there is correlation between the fistula’s morphology and other cardiac functional findings and clinical data.Materials and methods: A group of 14,308 patients who were diagnosed in coronary CTA was retrospectively analysed. Achieved data were related to referrals.Results: Coronary artery fistula frequency was 0.43% in the examined population. The assessment of coronary artery disease was the most frequent indication for the examination. In 2 out of 3 cases the diagnosis of CAFs was incidental. Fistulas to cardiac chambers were significantly shorter than those to other vascular structures (19.9 vs. 61.8 mm, respectively, p = 0.001). Pulmonary trunk was most often the drainage site. Fistulas with singular supply and drainage constituted the majority. The new morphologic classification of CAFs was introduced with linear, spiral, aneurysmal, grid-like and mixed types. Most numerous was the spiral type group. Patients with aneurysmal fistulas had a tendency for wider diameter of aorta and pulmonary trunk. Smallest left ventricle fraction was observed in gridlike fistulas (48.0%, comparing to 59.2% for all patients with fistulas, p = 0.001). Concomitant abnormalities were found in 13.1% of CAFs patients.Conclusions: Computed tomography angiography has proven to be a useful tool in CAFs detection and morphological assessment. Proposed classification may simplify the predictions whether fistula has a significant influence on cardiac function; however, further studies are needed
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