Objective To estimate the effective dose during 64-slice CT examination on head,chest and abdomen and determine the conversion coefficient of effective dose and dose length product(DLP).Methods The plain CT scan wag performed in 48 cases on head,50 cases on chest and 45 cages on abdomen using GE Lightspeed 64-slice spiral CT.1The Kv,Ma,scan time,CTDIvol,and DLP were recorded in each examination.Effective dose on patients Was estimated using the SR 250 software.Results The effective dose on head,chest and abdomen was(3.1±0.1),(6.9±0.1)and(8.0±0.1)mSv,and the conversion Coeffieient was 0.0025,0.0191 and 0.0166 mSv·mGy-1·cm-1 respectively.Conclusion CTDIvol、DLP and effective dose were recommended for patient dose control during CT examination.The conversion factor of effective dose and DLP were recommended for radiation risk evaluation during different X-ray examinations.

Objective to compare the calculated effective radiation dose variations in cardiac interventional procedures of coronary angiography (CAG) and percutaneous transluminal coronary angioplasty (PCI) by using the different tissue weighting factors recommended by ICRP Publication 60 with that recommended by ICRP Publication 103. Methods Measurements of organ doses were carried out with an anthropomorphic phantom equipped with thermoluminecent dosimetry. The effective radiation doses were separately calculated using the tissue weighting factors provided by ICRP 60 and provided by ICRP 103, and the results obtained from ICRP 60 were compared with that obtained from ICRP 103. Conversion factors of effective, radiation dose to dose area product (DAP) were also calculated according to different publication.Results The variations in the effective dose were 6.88% for CAG and 8.46% for PCI. The effective dose variations in CAG and PCI were. 7.25% and 8.76% for female and were 6.51% and 8.17% for male,respectively. The effective conversion factors of DAP were. 0.10 ～ 0.11 and 0.13 ～ 0.14 for CAG and PCI,respectively, according to ICRP 60 and 103. Conclusion The variation of conversion factors of effective dose indicates that in making estimation of effective radiation dose. by using the widely accepted conversion factors, the adjustment of organ weighting factors recommended by ICRP 103 should be considered.

Objective To assess the dose and image quality using a C-arm CT (DynaCT) system and compare the difference of image quality and radiation dose between DynaCT and Multi slice CT (MSCT). Methods Effective doses were measured from an anthropomorphic phantom with embedded thermoluminescence dosimeters (TLDs).For DynaCT,automatic exposure control (AEC) and high-quality (20 s rotation time) scans were used. For MSCT,scanning protocols for head were examined with conventional exposure conditions. Catphan phantom(Phantom Lab,USA) was used to evaluate the image quality for DynaCT and MSCT. Results For DynaCT,the effective doses from head scanning were 1.10 mSv; for MSCT,the effective doses from head scanning were 2.07 mSv,and there was a significant difference of organ dose between DynaCT and MSCT(P

Objective To investigate the influence of organ dose and effective dose on patients for different Z value during head,chest and abdomen CT scan. Methods With equispaced displacement on axis Z,organ dose and effective dose was estimated by using SR250 software with commonly used CT exposure parameters. Results Effective dose changed gradually for different Z value,some organ dose was sensitive to the Z location. Conclusion It is necessary to avoid X-ray sensitive organ in CT examination to minimize radiation risk.

Objective to compare the calculated effective radiation dose variations in cardiac interventional procedures of coronary angiography(CAG)and percutaneous transluminal coronary angioplasty (PCI)by using the different tissue weighting factors recommended by ICRP Publication 60 with that recommended by ICRP Publication 103.Methods Measurements of organ doses were carried out with an anthropomorphic phantom equipped with thermoluminecent dosimetry.The effective radiation doses were separately calculated using the tissue weighting factors provided by ICRP 60 and provided by ICRP 103,and the results obtained from ICRP 60 were compared with that obtained from ICRP 103.Conversion factors of effective radiation dose to dose area product(DAP)were also calculated according to different publication. Results The variations in the effective dose were 6.88%for CAG and 8.46%for PCI.The effective dose variations in CAG and PCI were 7.25%and 8.76%for female and were 6.51%and 8.17%for male, respectively.The effective conversion factors of DAP were 0.10～0.11 and 0.13～0.14 for CAG and PCI, respectively,according to ICRP 60 and 103.Conclusion The variation of conversion factors of effective dose indicates that in making estimation of effective radiation dose by using the widely accepted conversion factors,the adjustment of organ weighting factors recommended by ICRP 103 should be considered.

OBJECTIVETo observe the effect of the postpone in skeletal muscle aging process of D-galactose rats by weight training and soy polypeptide supplement in 6 weeks, and discuss the initial mechanism.

METHODSixty male SD rats (three month old)were randomly assigned: 6 week control (C6,) and 6 week model (M6) 6 for each group, 12 week model (M12), big load (B12), small load (S12), peptide (P12), peptide + big load (PB12) and peptide + small load group (PS12) 8 for each group, eight fourteen month rats were taken in the natural aging group. The rats were killed by the end of 6th week and 12th week, tested the indicators.

RESULTCompare with group C6, the indicators in group M6 showed aging in different levels; Compare with group M12, weight training or soy polypeptide supplement in all intervention groups could increase the content of skeletal muscle superoxide dismutase (SOD), SOD/MDA, the serum growth hormone(GH), insulin-like growth factor-1 (IGF-I)and skeletal muscle IGF-I mRNA, decreased the malondialdehyde (MDA) content of skeletal muscle, and they had notable interaction.

CONCLUSIONRat skeletal muscle aging model can be copied successfully by D-galactose hypodermic, and go on with 6-week weight training or soy polypeptide supplement, they can postpone the skeletal muscle aging process of D-galactose rats, and the two interference way united can have more obvious effect. Its preliminary mechanism may be related to the reduction of skeletal muscle oxidative stress and lipid peroxidation, the correction of hormones and related factors metabolic disorders, the elevation of skeletal muscle IGF-I mRNA expression and so on.

Aging ; physiology ; Animals ; Galactose ; Growth Hormone ; blood ; Insulin-Like Growth Factor I ; metabolism ; Male ; Malondialdehyde ; metabolism ; Muscle, Skeletal ; drug effects ; physiology ; Physical Conditioning, Animal ; physiology ; Rats ; Rats, Sprague-Dawley ; Soybean Proteins ; pharmacology ; Soybeans ; chemistry ; Superoxide Dismutase ; metabolism

By integrating data of sci-tech novelty retrieaval and internet data,the paper makes a precise analysis of the potential demands,interest,interest,tendency,preferences and habits of users of novelty retrieval.From the perspective of big data technology,it analyzes the feasibility of designing targeted and deep-level services for mass user data,puts forward the framework and method of conducting deep-level and precise service recommendation based on users of sci-tech novelty retrieval,and studies the opportunity to provide these users with deep-level and precise services.

Objective: To estalish a rat model system in which periapical lesions were induced by pulp exposure and infection from the oral environment. Methods: The pulps of mandibular molar of 16 SD rats were surgically exposed and kept open to be induced for infection from the oral environment. The rats were killed 1, 2, 3, 4 weeks after operation respectively. Radiographic image analysis was performed by means of computer linked to a video image digital analysis system. In addition, specimens were decalicified, sectioned, HE stained and examined under microscope. Results: Periapical lesions were readily detectable as early as 1 week after pulp exposure. A significant increase in lesion area was detected from 1 to 3 weeks in a time-dependent manner, the lesion declined a little bit in 4 weeks. Slight inflammatory cell infiltration and alveolar bone resorption were observed in the periapical tissue in the 1-week-samples, total pulp necrosis in the 2-week-samples, apical abscess and bone destruction in the 3-week-samples. Decreased infiltration and the matured osteoblasts were found on the surface of the bone in the 4-week-samples. Conclusion: Pulp exposure can induce periapical lesion in rat. A period of rapid lesion development occurs between day 7 and day 21 after pulp exposure (active phase), and a period of slower development follows thereafter (chronic phase).

Objective To solve the encountered problem of lack of space and dyskinesia of detector in dual energy X-ray absorptiometry system, Methods The method used PartitionMagic8.0 software to partition space in hard disk and added the load to keep the detector balance for moving, Results The original software can run in hard disk, and the pulleys are not gotten force from side. Conclusion The reason of problem is analyzed to find the method that can reduce the percentage for system failure and improve precision and accuracy of data.