Although the function of vitamin D as a regulator of calcium and bone metabolism is well recognized, its role as an immunomodulator, regulator of cellular differentiation, and anti-inflammatory and ...antifibrotic actions is being increasingly noted. It is estimated that one-third of liver cirrhosis patients are vitamin D deficient. It has been reported that as liver disease progresses, the incidence of vitamin D deficiency rises. Several clinical implications of vitamin D levels have been proposed, including as a prognostic marker for the assessment of mortality in liver cirrhosis.
To analyze the link between levels of vitamin D and decompensation of liver cirrhosis.
This observational, cross-sectional study was conducted on 100 patients with liver cirrhosis admitted at Goa Medical College, a tertiary care government hospital in Goa, from March 2020 to February 2022. Demographic profile, history, and examination findings were recorded, and biochemical analysis included vitamin D levels. Child-Pugh (CP) and Model for End-Stage Liver Disease (MELD) scores were calculated, and based on these, patients were grouped into classes of disease severity. Data was interpreted using Statistical Package for the Social Sciences (SPSS) version 22.
Mean age of the study population was 50 ± 9 years, with a 96% male predominance. Mean levels of vitamin D were 12.13, with a standard deviation (SD) of 7.38. Significant differences were noted between different classes of CP score (CPS). A vitamin D deficient state was noted in 93.3% CP class C group and 0% of class A group. A statistically significant association was demonstrated between low levels of vitamin D and CP class severity of liver dysfunction as well as MELD scores.
This study confirms a high prevalence of vitamin D deficiency among patients with liver cirrhosis concurrent with the results of similar studies done earlier. More importantly, with increasing severity of hepatic decompensation as measured by CPS and MELD, vitamin D concentrations reduce.
Ectopic thyroid tissue is a rare developmental abnormality involving aberrant embryogenesis of the thyroid gland during passage from the primitive foregut to the pretracheal position. The most ...frequent position is the base of the tongue (lingual thyroid); however, it has been described in other sites, such as the submandibular region, trachea, mediastinum, and subdiaphragmatic regions.Here, we report a case of an adenomatous goiter that developed in mediastinal thyroid tissue without any connection to the pretracheal thyroid gland.
The Belle II SVD data readout system Thalmeier, R.; Adamczyk, K.; Aihara, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2017, Letnik:
845
Journal Article
Recenzirano
Odprti dostop
The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the ...standard model.
172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC).
Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network.
We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.
The silicon vertex detector of the Belle II experiment Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Odprti dostop
The silicon vertex detector of the Belle II experiment, structured in a lantern shape, consists of four layers of ladders, fabricated from two to five silicon sensors. The APV25 readout ASIC chips ...are mounted on one side of the ladder to minimize the signal path for reducing the capacitive noise; signals from the sensor backside are transmitted to the chip by bent flexible fan-out circuits. The ladder is assembled using several dedicated jigs. Sensor motion on the jig is minimized by vacuum chucking. The gluing procedure provides such a rigid foundation that later leads to the desired wire bonding performance. The full ladder with electrically functional sensors is consistently completed with a fully developed assembly procedure, and its sensor offsets from the design values are found to be less than 200μm. The potential functionality of the ladder is also demonstrated by the radioactive source test.
Abstract
The Silicon Vertex Detector of Belle II is a
state-of-the-art tracking and vertexing system based on double-sided
silicon strip sensors, designed and fabricated by a large
international ...collaboration in the period 2012–2018. Since 2019 it
has been in operation providing high quality data with a small
number of defective channels (<1%), a large hit-finding
efficiency (>99%), a good signal-to-noise ratio (well in excess
of 10 for all sensor configurations and tracks). Together with the
good control over the alignment, these are all essential factors to
achieve good tracking reconstruction and physics performance. In
this extended paper we try to document all the aspects of the SVD
challenges and achievements, in the spirit of providing information
to the broader community and help the development of high quality
detector systems, which are essential tools to carry out physics
research.
The Belle II silicon vertex detector assembly and mechanics Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2017, Letnik:
845
Journal Article
Recenzirano
The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of ...the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules.
Finally, some results from the latest test-beam are reported.
Belle II silicon vertex detector Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2016, Letnik:
831
Journal Article
Recenzirano
The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of ...the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by an inner tracking device comprising two layers of pixelated silicon detector and four layers of silicon vertex detector based on double-sided microstrip sensors. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector.
The Belle-II VerteX Detector (VXD) has been designed to improve the performances with respect to Belle and to cope with an unprecedented luminosity of 8×1035cm−2s−1 achievable by the SuperKEKB. ...Special care is needed to monitor both the radiation dose accumulated throughout the life of the experiment and the instantaneous radiation rate, in order to be able to promptly react to sudden spikes for the purpose of protecting the detectors. A radiation monitoring and beam abort system based on single-crystal diamond sensors is now under an active development for the VXD. The sensors will be placed in several key positions in the vicinity of the interaction region. The severe space limitations require a challenging remote readout of the sensors.
A silicon vertex detector (SVD) for the Belle-II experiment comprises four layers of double-sided silicon strip detectors (DSSDs), assembled in a ladder-like structure. Each ladder module of the ...outermost SVD layer has four rectangular and one trapezoidal DSSDs supported by two carbon-fiber ribs. In order to achieve a good signal-to-noise ratio and minimize material budget, a novel chip-on-sensor “Origami” method has been employed for the three rectangular sensors that are sandwiched between the backward rectangular and forward (slanted) trapezoidal sensors. This paper describes the bonding procedures developed for making electrical connections between sensors and signal fan-out flex circuits (i.e., pitch adapters), and between pitch adapters and readout chips as well as the results in terms of the achieved bonding quality and pull force.
•Gluing and wire binding for Belle-II SVD are studied.•Gluing robot and Origami module are used.•QA are satisfied in terms of the achieved bonding throughput and the pull force.•Result will be applied for L6 ladder assembly.
Belle II SVD ladder assembly procedure and electrical qualification Adamczyk, K.; Aihara, H.; Angelini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Odprti dostop
The Belle II experiment at the SuperKEKB asymmetric e+e− collider in Japan will operate at a luminosity approximately 50 times larger than its predecessor (Belle). At its heart lies a six-layer ...vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is time-dependent CP violation asymmetry, which hinges on a precise charged-track vertex determination. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision three dimensional coordinate measurements of the jigs used in assembly as well as of the final SVD modules.
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