ABSTRACT
Objective:To investigate the effect of deviation from the isocenter point on the quality of CT images at the same radiation dose.Methods:A 160-layer CT scanner was used to scan the phantom at isocenter and deviations of 3, 6, 9, 12 and 15 cm. CT was performed with the following parameters: 120 kVp; 400 mAs; slice thickness, 1 mm; and slice increment, 1 mm. Images were reconstructed using the filtered back projection algorithm. Noise power spectrum (NPS), task transfer function (TTF) and detectability index (d′) were measured. NPS peak was used to quantify the noise magnitude and TTF 50% was used to quantify the spatial resolution. NPS, TTF and d′ were compared using one-way ANOVA. Results:The NPS average spatial frequency, spatial resolution and d′ values gradually decreased as the offset distance increased and the amount of noise increased. NPS peak at isocenter and deviations of 3 cm, 6 cm, 9 cm, 12 cm and 15 cm were (94.31±1.48), (104.25±1.46), (131.44±1.96), (171.86±1.91), (224.05±1.37), (286.51±2.09)HU 2·mm 2, respectively ( F=37 241.91, P<0.001). And d′ values of 2 mm low-contrast lesions were 3.51±0.06, 3.31±0.04, 3.01±0.04, 2.59±0.06, 2.21±0.03, 1.88±0.03, respectively. The reduction in spatial resolution was more pronounced for high contrast, and the d′ values decreased to a similar extent for various types of lesions. The noise was increased by about 82%, the high contrast spatial resolution was decreased by about 12%, and the d′ value was decreased by about 26% at 9 cm from the isocenter point (all P<0.05). The noise was increased by about 204%, the high contrast spatial resolution was decreased by about 27%, and the d′ value was decreased by about 45% at 15 cm from the isocenter (all P<0.05). Conclusion:The CT image quality was decreased with the increase of the offset distance from the CT isocenter point. The image quality was severely compromised at offset distances greater than 9 cm.
ABSTRACT
Objective To investigate and analyze the similarities of allergens in children of the same family with susceptibility to the same genetic background and environmental factors. Methods From January 2013 to December 2017,a total of 142 pairs of children with allergic diseases aged 0-15 years and their siblings ( 284 cases) were collected from the outpatient or hospitalized treatment of Pediatrics and otolaryngology department of the First People′s Hospital of Foshan City,the Third Affiliated Hospital of Sun Yat-sen University. The elder group was brother or sister (142 cases),and the younger group was brother or sister ( 142 cases ) . The serum allergen sIgE was tested by Allergy Screen allergen detection system (developed by Germany MEDIWISS Company) and the similarity of allergens was analyzed. Results A total of 142 siblings ( 284 cases ) had systemic symptoms of allergic diseases in varying degrees, including respiratory symptoms ( cough ( 47 cases in the old group,32 cases in the young group), χ2 ＝3. 946, P＝0. 047),nasal obstruction ( 41 cases in the old group,19 cases in the young group, χ2 ＝ 10. 227, P ＝0. 001),runny nose (46 cases in the old group,26 cases in the young group,χ2＝7. 442,P＝0. 006), gastrointestinal symptoms (abdominal pain (11cases in the old group,7 cases in the young group,χ2＝4. 63, P＝0. 031),skin symptoms(urticaria (18 cases in the old group,8 cases in the young group,χ2＝4. 234,P＝0. 037)) and so on,the difference was statistically significant. Some children have multiple organ system symptoms at the same time. There was no significant difference between the old group and the young group in the early use of antibiotics,mode of production and feeding mode within 6 months (all P＞0. 05). Among the two groups,house dust mite and cockroach (r＝0. 831,P＜0. 05),dog hair and house dust ( r＝0. 717,P＜0. 05),cypress,elm,willow,birch,oak,maple,walnut,sycamore,poplar and Dianqing,branching,yanqu, and heiqu ( r ＝ 0. 683, P＜ 0. 05 ) . Conclusion With the same genetic background and the same environmental factors,the allergens in siblings are similar.
ABSTRACT
Objective To study the electrolyte status of 50 infants with severe pneumonia. Method By means of retrospective way to analyze the electrolyte level of blood sample from 50 young children. Results The sequences of electrolyte disturbances in the 50 young children with severe pneumonia were hyponatremia(34%), hypokalemia(30%),hypocalcemia(18%),hypochloremia(16%),hypernatremia(12%),and heperkalemia(10%). Conclusion Young children with severe pneumonia often have electrolyte disturbances of various kinds at the same time; electrolyte evaluations of blood samples from such young children should be done routinely, so that problems can be found early, and correcting measures be taken in time.
ABSTRACT
A simple and precise method using high-performane. liquid chromatography was developed for the simultaneous determination of three bisbenzylisoquinoline alkaloids, namely tetrandrine, demethyltetrandrine and berbamine, in Stephania tetrandra S. Moore.A reversed-phase system consisting of chemically bonded ODS silica gel column and methanolacetonitrile-H2O (3: 1:1) containing 0.06% diethylamine as the mobile phase was used. The three alkaloids were completely separated within 10 min. The analytical results for various samples were presented.