350 research outputs found
Thyroid exposure in brain CT-scan and skull X-ray, using different levels of mA and Kvp with and without thyroid shield.
زمینه و هدف: امروزه در تصویر برداری های رادیولوژیکی از جمجمه، پرتو گیری تیروئید، به عنوان یک عضو بحرانی، اهمیت فراوانی دارد. این مطالعه با هدف بررسی دز دریافتی تیروئید در دو روش سی تی اسکن مغز و رادیوگرافی معمول جمجمه، با اعمال مقادیر مختلف شدت جریان و اختلاف پتانسیل با و بدون استفاده از شیلد تیروئید انجام شد. روش بررسی: در این مطالعه توصیفی- تحلیلی 350 بیمارسرپایی انتخاب و قبل از پرتودهی 2 عدد قرص TLD (Thermo luminescence Dosimetr) بر روی تیروئید هر بیمار نصب شد. برای انجام سی تی اسکن مغز سه سطح مختلف شدت جریان (در 210 بیمار) و برای رادیوگرافی معمول جمجمه دو سطح مختلف اختلاف پتانسیـــل (در 140 بیمار) استفاده گردید. پرتودهی ها با و بدون استفاده از شیلد تیروئید انجام شد. سپس TLD ها قرائت و داده به کمک آزمون آماری t دانشجویی تجزیه و تحلیل شدند. یافته ها: در آزمون های سی تی اسکن (با Kvp ثابت)، با کاهش شدت جریان از 150 به 125 میلی آمپر میزان پرتوگیری تیروئید از 38/9±101 به 04/8±2/82 میلی رم رسید (01/0
INVESTIGATION OF GENETIC DIVERSITY, PHYLOGENY AND SUB-SPECIES STRUCTURING IN THE ENTOMOPATHOGENIC NEMATODE HETERORHABDITIS
We used Random amplified polymorphic DNA (RAPDs), partial ribosomal DNA (rDNA), the mitochondrial gene cytochrome oxidase subunit I (cox1) and major sperm protein (msp) sequence analysis to investigate genetic diversity and population structure in Heterorhabditis bacteriophora, H. indica, H. marelata, H. megidis, H. downesi and H. zealandica comprising 18 isolates collected from different parts of the world. Blastn similarity search performed for the partial rDNA sequences confirmed the identity of Heterorhabditis species and suggested that all the unknown isolates belonged to H. bacteriophora. Blastn e-values for the species and isolates ranged between 0 to 9e-145. Genetic diversity and phylogenetic analysis produced dendrograms that showed high degrees of genetic variations among Heterorhabditis species with the overall average pairwise distance values of 0.3217, 0.6391, 0.7963 and 0.0572 for RAPD, partial rDNA, cox1 and msp, respectively. Although we expected low genetic diversity among H. bacteriophora isolates due to alternate automictic and amphimictic lifecycle and lack of long distance movement capability restricting gene flow, our results demonstrate highly structured genetic variation among the isolates. Phylogenetic analysis showed that H. bacteriophora isolates is a species complex that contain at least two two new species KMD10 and GPS5. Further H. bacteriophora sensu Pionar populations can be divided into two major groups: “HP88” and “Oswego”. We conclude that strictly relying on ITS sequences based blastn for Heterorhabditis species identification is misleading.OARD
Dose assessment and radioactivity of the mineral water resources of Dimeh springs in the Chaharmahal and Bakhtiari Province, Iran
One of the main sources of public exposure from natural radioactivity is radium and radon and its short lived decay products. The aim of this study is focused on determining the concentration of mentioned radionuclides in the mineral water resources in one of the highest altitude regions (Zagros Mountains), the Chaharmahal and Bakhtiari province, in South-West Iran, namely the Dimeh springs. Eighty drinking spring water samples were taken from the Dimeh springs (ten samples for each spring) to determine radium-226 ( 226Ra) and radon-222 (222Rn) concentrations using the emanation method and a liquid scintillation counting method, respectively. The results of this study showed that the effective dose from the consumption of drinking water of Dimeh springs (6.4 μSv/y) is not comparable to the other annual effective dose such as inhalation of radon and its products in cosmic and terrestrial rays published by one of the authors previously. Also, the annual effective dose measured here is much lower than the worldwide mean value 0.45 mSv reported by USCEAR, 2000 and is also low enough and below the proposed limits in other countries and this is the reason why this sources of water may be considered as safe drinking water in the region
Problems Experienced by Adolescents with Autism Spectrum Disorder: Exploring Social, Educational and Economic Variables
The study investigates the problems of adolescents with Autism Spectrum Disorder (ASD) from the perspective of ASD specialists and adolescent’s families. It comprises of 228 ASD specialists and 294 families of ASD adolescents. The sample represents all areas of the Kingdom of Saudi Arabia (henceforth – KSA): north, south, east, west and centre. Variables of the study are adolescents’ gender, age, residential area, as well as the qualification of ASD specialists and family members. To accomplish the study, the researchers designed a questionnaire that includes variables regarding six significant problems: Educational, Recreational, Economic, Health, Psychological, and Social. The results reveal that families rate the economic problems higher than average, while the recreational ones – lower; specialists rate economic problems higher than average and educational ones – the lowest. As for gender variable, specialists and families note the differences in favour of females; for age variable, specialists and families note that 15-18 years old ASD adolescents have more problems. The results show that qualification of specialists as well as family members is of significant relevance in relation to ASD adolescents. Both specialists and family members are mostly from the central regions
Folliculogenesis and follicular fluid adiponectin in cows: Its alterations and relationships with ovarian function [Folikulogeneza i adiponektin u folikularnoj tekućini krava: Promjene i odnos s funkcijom jajnika]
The objectives of the present study were to study the dynamic changes in adiponectin concentration in the growing luteal as well as the preovulatory follicles in dairy cows. In the first study, the ovaries and blood of 15 Holstein dairy cows in the luteal phase were collected from a slaughterhouse. Clear antral follicles were divided into three diameter groups (small, 3-5 mm; medium, 6-9 mm and large, ≥10 mm) and their fluid was aspirated. In the second study, the coccygeal blood and fluid of the preovulatory follicles of eight live Holstein dairy cows were aspirated transrectally, using a transrectal-guided fine-needle. Concentrations of adiponectin in the serum, and follicular fluid and progesterone in the serum were measured. Serum adiponectin concentrations in both luteal and follicular phases were higher than the follicular fluid adiponectin concentrations in all types of follicles (P0.05), and the reduction was seen in preovulatory follicles in comparison with small follicles (P = 0.001). In the luteal phase, a significant positive correlation was observed between the adiponectin concentrations in different sized follicles, and also in the serum progesterone and follicular fluid adiponectin of follicles (P<0.05). In conclusion, lower adiponectin concentrations in blood serum and preovulatory follicles in comparison to luteal growing follicles reflect the effect of ovarian stage on adiponectin alterations
Analysis of advanced supercritical carbon dioxide power cycles with a bottoming cycle for concentrating solar power applications
A number of studies have been performed to assess the potential of using supercritical carbon dioxide (S-CO 2 ) in closed-loop Brayton cycles for power generation. Different configurations have been examined among which recompression and partial cooling configurations have been found very promising, especially for concentrating solar power (CSP) applications. It has been demonstrated that the S-CO 2 Brayton cycle using these configurations is capable of achieving more than 50% efficiency at operating conditions that could be achieved in central receiver tower type CSP systems. Although this efficiency is high, it might be further improved by considering an appropriate bottoming cycle utilizing waste heat from the top S-CO 2 Brayton cycle. The organic Rankine cycle (ORC) is one alternative proposed for this purpose; however, its performance is substantially affected by the selection of the working fluid. In this paper, a simple S-CO 2 Brayton cycle, a recompression S-CO 2 Brayton cycle, and a partial cooling S-CO 2 Brayton cycle are first simulated and compared with the available data in the literature. Then, an ORC is added to each configuration for utilizing the waste heat. Different working fluids are examined for the bottoming cycles and the operating conditions are optimized. The combined cycle efficiencies and turbine expansion ratios are compared to find the appropriate working fluids for each configuration. It is also shown that combined recompression-ORC cycle achieves higher efficiency compared with other configurations
A secure key distribution protocol based on hash functions and a quantum-authenticated channel using 6DP (KDP-6DP)
Security is the most tedious problem in highly sensitive communications. Quantum security is the key
issue in solving the problem. A key distribution protocol based on the use of hash functions is proposed.
The essential part of the protocol depends on sending a string of random characters from sender to
receiver. Then, a selected hash or a cascade of two hash functions and a long-term shared secret are used
to construct the key. Consequently, the session key is generated on-site by independently applying a hash
function on the random string at the sender and receiver sides. This protocol requires a reliable method of
authentication. Therefore, it is further proposed to use an out-of-band authentication methodology based
on the deterministic six-state quantum authentication protocol that is referred to as 6DP
Pancreatic Allograft Thrombosis: Suggestion for a CT grading system and management algorithm
Pancreatic allograft thrombosis (PAT) remains the leading cause of non-immunological graft failure. Herein we propose a new CT grading system of PAT to identify risk factors for allograft loss and outline a management algorithm by retrospective review of consecutive pancreatic transplants between 2009-2014. Triple-phase CT scans were graded independently by two radiologists as; Grade 0 – no thrombosis, Grade 1 – peripheral thrombosis, Grade 2 – intermediate non-occlusive thrombosis and Grade 3 – central occlusive thrombosis. Twenty-four of 103 (23.3%) recipients were diagnosed with PAT (including grade 1). Three grafts (2.9%) were lost due to portal vein thrombosis. On multivariate analysis, pancreas after SPK/PAK transplant, acute rejection and CT finding peri-pancreatic oedema and/or inflammatory change were significant risk factors of PAT. Retrospective review of CT images revealed more grade 1 and 2 thromboses than were initially reported. There was no significant difference in graft or patient survival, post-operative stay or morbidity of recipients with grade 1 or 2 thrombosis who were or were not anticoagulated. Our data suggest that therapeutic anticoagulation is not necessary for grade 1 and 2 arterial and grade 1 venous thrombosis. The proposed grading system can assist clinicians in decision making and provide standardised reporting for future studies
Phenotypically distinct neutrophils patrol uninfected human and mouse lymph nodes.
Neutrophils play a key role in innate immunity. As the dominant circulating phagocyte, they are rapidly recruited from the bloodstream to sites of infection or injury to internalize and destroy microbes. More recently, neutrophils have been identified in uninfected organs, challenging the classical view of their function. Here we show that neutrophils were present in lymph nodes (LNs) in homeostasis. Using flow cytometry and confocal imaging, we identified neutrophils within LNs in naive, unchallenged mice, including LNs draining the skin, lungs, and gastrointestinal tract. Neutrophils were enriched within specific anatomical regions, in the interfollicular zone, a site of T cell activation. Intravital two-photon microscopy demonstrated that LN neutrophils were motile, trafficked into LNs from both blood and tissues via high endothelial venules and afferent lymphatics, respectively, and formed interactions with dendritic cells in LNs. Murine and human LN neutrophils had a distinct phenotype compared with circulating neutrophils, with higher major histocompatibility complex II (MHCII) expression, suggesting a potential role in CD4 T cell activation. Upon ex vivo stimulation with IgG immune complex (IC), neutrophils up-regulated expression of MHCII and costimulatory molecules and increased T cell activation. In vivo, neutrophils were capable of delivering circulating IC to LNs, suggesting a broader functional remit. Overall, our data challenge the perception that neutrophil patrol is limited to the circulation in homeostasis, adding LNs to their routine surveillance territory.L.S.C.L. was funded by Wellcome Trust (104384/Z/14/Z). M.R.C. is supported by National Institute of Health Research (NIHR) Cambridge Biomedical Research Centre, Chan-Zuckerburg Initiative Human Cell Atlas Technology Development Grant, Medical Research Council New Investigator Research Grant (MR/N024907/1), Arthritis Research UK Cure Challenge Research Grant (21777), and NIHR Research Professorship (RP-2017-08- ST2-002)
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