Pixel sensitivity variation in a CdTe-Medipix2 detector using poly-energetic x-rays

We have a 1-mm-thick cadmium telluride (CdTe) sensor bump-bonded to a Medipix2 readout chip. This detector has been characterized using a poly-energetic x-ray beam. Open beam images (i.e. without an attenuating specimen between the x-ray source and the detector) have been acquired at room temperature using the MARS-CT system. Profiles of various rows and columns were analyzed for one hundred, 35-ms exposures taken with a bias voltage of -300 V (operating in electron collection mode). A region of increased sensitivity is observed around the edges of the detector. A reasonably periodic, repeatable variation in pixel sensitivity is observed. Some small regions with very low sensitivity and others with zero signals are also observed. Surrounding these regions are circular rings of pixels with higher counts. At higher flux (higher tube current in the x-ray source) there is evidence of saturation of the detector assembly. In this paper we present our understanding of the origin of these features and demonstrate the improved image quality obtained after correcting for these variations

Dying at home or in an institution: perspectives of Dutch physicians and bereaved relatives

Introduction Previous studies have shown that most people prefer to die at their own home. We investigated whether physicians or bereaved relatives in retrospect differently appreciate the dying of patients in an institution or at home. Materials and methods Of 128 patients with incurable cancer who were followed in the last phase of their lives, 103 passed away during follow-up. After death, physicians filled out a written questionnaire for 102 of these patients, and 63 bereaved relatives were personally interviewed. Results Of 103 patients, 49 died in an institution (mostly a hospital), and 54 died at home (or in two cases in a home-like situation). Patients who had been living with a partner relatively often died at home. Bereaved relatives knew of the patient’s wish to die at home in 25 out of 63 cases; 20 of these patients actually died at home. Thirty-one patients had no known preference concerning their place of dying. Most symptoms and the care provided to address them were equally prevalent in patients dying in an institution and patients dying at home. Bereaved relatives were in general quite satisfied about the provision of medical and nursing care in both settings. Conclusion We conclude that most patients’ preferences concerning the place of dying can be met. In about half of all cases, patients do not seem to have a clear preference concerning their place of dying, which is apparently not a major concern for many people. We found no indication that dying in an institution or at home involves major differences in the process and quality of dying

Bifidobacterium breve and Lactobacillus rhamnosus treatment is as effective as budesonide at reducing inflammation in a murine model for chronic asthma

__Background:__ Asthma is estimated to affect as many as 300 million people worldwide and its incidence and prevalence are rapidly increasing throughout the world, especially in children and within developing countries. Recently, there has been a growing interest in the use of potentially beneficial bacteria for allergic diseases. This study is aimed at exploring the therapeutic effects of long-term treatment with two different beneficial bacterial strains (Bifidobacterium breve M-16 V and Lactobacillus rhamnosus NutRes1) and a glucocorticoid (budesonide), as a reference treatment, on inflammatory response in a murine model for chronic allergic asthma. __Methods:__ To mimic the chronic disease in asthmatic patients, we used the murine ovalbumin-induced asthma model combined with prolonged allergen exposure. Airway function; pulmonary airway inflammation; airway remodelling, mRNA expression of pattern recognition receptors, Th-specific cytokines and transcription factors in lung tissue; mast cell degranulation; in vitro T cell activation; and expression of Foxp3 in blood Th cells were examined. __Results:__ Lactobacillus rhamnosus reduced lung resistance to a similar extent as budesonide treatment in chronically asthmatic mice. Pulmonary airway inflammation, mast cell degranulation, T cell activation and airway remodelling were suppressed by all treatments. Beneficial bacteria and budesonide differentially modulated the expression of toll-like receptors (TLRs), nod-like receptors (NLRs), cytokines and T cell transcription factors. Bifidobacterium breve induced regulatory T cell responses in the airways by increasing Il10 and Foxp3 transcription in lung tissue as well as systemic by augmenting the mean fluorescence intensity of Foxp3 in blood CD4+ T cells. __Conclusion:__ These findings show that Bifidobacterium breve M-16 V and Lactobacillus rhamnosus NutRes1 have strong anti-inflammatory properties that are comparable to budesonide and therefore may be beneficial in the treatment of chronic asthma

Development and testing of a fast fourier transform high dynamic-range spectral diagnostics for millimeter wave characterization

A fast Fourier transform (FFT) based wide range millimeter wave diagnostics for spectral characterization of scattered millimeter waves in plasmas has been successfully brought into operation. The scattered millimeter waves are heterodyne downconverted and directly digitized using a fast analog-digital converter and a compact peripheral component interconnect computer. Frequency spectra are obtained by FFT in the time domain of the intermediate frequency signal. The scattered millimeter waves are generated during high power electron cyclotron resonance heating experiments on the TEXTOR tokamak and demonstrate the performance of the diagnostics and, in particular, the usability of direct digitizing and Fourier transformation of millimeter wave signals. The diagnostics is able to acquire 4 GHz wide spectra of signals in the range of 136-140 GHz. The rate of spectra is tunable and has been tested between 200 000 spectra/s with a frequency resolution of 100 MHz and 120 spectra/s with a frequency resolution of 25 kHz. The respective dynamic ranges are 52 and 88 dB. Major benefits of the new diagnostics are a tunable time and frequency resolution due to postdetection, near-real time processing of the acquired data. This diagnostics has a wider application in astrophysics, earth observation, plasma physics, and molecular spectroscopy for the detection and analysis of millimeter wave radiation, providing high-resolution spectra at high temporal resolution and large dynamic range

Comparing three alternative optimisation methods for the treatment planning of bulbs

We developed a decision support system to plan the treatment for large amounts of bulbs in stores. Before the actual treatment season a tactical treatment plan is constructed. The treatment plan supports the operational decisions such as place-ment and movements during the actual treatment season. We used local search to optimize the treatment plan

Comparing three alternative optimisation methods for the treatment planning of bulbs

We developed a decision support system to plan the treatment for large amounts of bulbs in stores. Before the actual treatment season a tactical treatment plan is constructed. The treatment plan supports the operational decisions such as place-ment and movements during the actual treatment season. We used local search to optimize the treatment plan

Comparing three alternative optimisation methods for the treatment planning of bulbs

We developed a decision support system to plan the treatment for large amounts of bulbs in stores. Before the actual treatment season a tactical treatment plan is constructed. The treatment plan supports the operational decisions such as place-ment and movements during the actual treatment season. We used local search to optimize the treatment pla

Pixel sensitivity variation in a CdTe-Medipix2 detector using poly-energetic x-rays

We have a 1-mm-thick cadmium telluride (CdTe) sensor bump-bonded to a Medipix2 readout chip. This detector has been characterized using a poly-energetic x-ray beam. Open beam images (i.e. without an attenuating specimen between the x-ray source and the detector) have been acquired at room temperature using the MARS-CT system. Profiles of various rows and columns were analyzed for one hundred, 35-ms exposures taken with a bias voltage of -300 V (operating in electron collection mode). A region of increased sensitivity is observed around the edges of the detector. A reasonably periodic, repeatable variation in pixel sensitivity is observed. Some small regions with very low sensitivity and others with zero signals are also observed. Surrounding these regions are circular rings of pixels with higher counts. At higher flux (higher tube current in the x-ray source) there is evidence of saturation of the detector assembly. In this paper we present our understanding of the origin of these features and demonstrate the improved image quality obtained after correcting for these variations