Objective:To investigate the dependence of geometric efficiency (GE) on beam collimation and tube voltage.Methods: The dose profile was measured under the conditions of different collimations and tube voltages and GE was calculated.Results: GE was found to be from 11% to 68%, GE at central position and periphery were found to range from 11% to 49% and 16% to 68% respectively, and weighted GE was found to be from 17% to 58%. GE was increased with beam collimation, while it was less pronounced on tube voltages.Conclusion:The dependence of GE on collimation was significant. Therefore, operators should choose appropriate collimations to reduce the dose burden of patients in CT examinations.

DNA Methylation ; Humans ; Poly(ADP-ribose) Polymerases ; genetics ; metabolism

Objective:To establish the quality control method of electrosurgical unit(ESU) through the safety performance test and data analysis for electrotome.Methods: According to the testing standard of ESU, Fluke ESA612 electrical safety analyzer and QA-ES II electrosurgery unit analyzer were applied to test the properties of ESU were using during 2015 and 2016, and the testing results were analyzed.Results:In 2015 and 2016, the qualified rate of quality control results were 79% and 81%, respectively; the problems of unqualified ESU were resolved and their hidden risks in clinical applications were eliminated.Conclusion: By testing the properties of ESU, we can master the performance of the machine; find and deal with the risk of machine in time, and avoid the hidden danger and enhance the risk management for ESU, so that the machine can be safely and effectively applied in clinical surgery.

Objective:To correct the characterizations of MDCT radiation dose by exploring the relationship between CTDIw,∞ and CTDIw.Methods: CTDI100 and CTDI∞ were measured under the conditions of different collimations, pitches and tube voltages of Siemens Definition Flash CT, and CTDIw and CTDIw,∞ were calculated.Results: There were significant differences between CTDIw and CTDIw,∞ which were measured at 0.05 level. And there were no significant differences between CTDIw,∞ after corrected and CTDIw,∞ which were measured at 0.05 level.Conclusion:The characterizations of MDCT which were commonly used were not accurate enough. The result after correction were very closed to the real CTDIw,∞. This showed that the method to correct CTDIw of Siemens Definition Flash CT was mostly accurate. And methods to correct CTDIw of other MDCT needed to be further studied.

Objective: The purpose of the current study was to investigate the correction coefficient of the characterizations of multi-detector CT (MDCT). Methods: The dose profile of Siemens SOMATOM Definition Flash CT scanner was measured with CT-SD 16 detector under the conditions of different collimations, pitches and tube voltages in phantoms of different diameters, and the ratio between weighted CTDI∞and weighted CTDI100 was calculated. Results:The ratio between weighted CTDI∞and weighted CTDI100, which is growing for increasing beam collimation, was found to range from 1.123 to 1.162 in head phantom and range from 1.118 to 1.173 in body phantom. Conclusion: For MDCT, the use of CTDI100, which is one of the most commonly used characterizations of CT, has always underestimated the levels of radiation dose. Therefore, CTDI100 should be corrected.

Objective To correlate vWF expression in the endothelium of transitional pulmonary arterioles from lung biopsy in patients with pulmonary hypertension (PH) secondary to left-to-right shunt congenital heart defects (CHD). The results will be compared to vWF expression in peripheral venous plasma pre-operatively and the early post-operative outcome. Methods Consecutive 70 cases of left-to-right shunt congenital heart defects were involved in the study, the age ranged from 4 months to 63 years. Pulmonary systolic pressure/systemic systolic pressure (Pp/Ps) was calculated from Swan-Ganz floating catheter monitoring before corrective operation. PH was found in 62 cases, with slight PH in 16, moderated PH in 24 and severe PH in 22. Non-PH in 8 cases. Twenty-six cases of non-heart and lung disease were involved in as control. Lung biopsy tissue was stained for routine pathologic classification and quantitative vWF expression, with testing vWF in the peripheral venous blood. Post-operative complication was noted. Results There was a statistically difference of vWF expression in the endothelium of pulmonary transitional arterioles between PH group and non-PH group, with reducing intensity in order of non-PH, slight Ph, moderate PH and severe PH. A negative relationship was statistically noted between Pp/Ps and vWF expression in the arteriole endothelium (=61.88-33.30x, r=-0.701, P

Adult ; Aged ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Pneumoconiosis ; epidemiology

In the present study, the specifically knockdown models of P-gp or MRP2 were constructed by using a series of chemically synthesized small interfering RNA (siRNA) in vitro. The expression of P-gp and MRP2 was measured by real-time PCR and Western blot, and the function was evaluated by applying P-gp and MRP2 substrate, rhodamine and methotrexate. The results showed that MRP2 siRNA-3 or P-gp siRNA-2 significantly decreased the mRNA expression of MRP2 or P-gp, the inhibition ratio was 68% or 84%; MRP2 siRNA-3 or P-gp siRNA-2 at a dose of 80 nmol x L(-1) significantly reduced the protein expression of MRP2 or P-gp at 48 h after treatment, the inhibition ratio was 62% or 70%. Meanwhile, other transporters were not influenced by siRNA. When pretreatment with MRP2 siRNA-3 or P-gp siRNA-2, the efflux of methotrexate or rhodamine decreased significantly and the intra-cellular concentration increased. The results suggested that chemically synthesized siRNA could significantly inhibit the expression and function of MRP2 and P-gp, and the model of RNAi in vitro could be used to evaluate the role of efflux transporters in transportation of drugs.

Objective To identify the clinical risk factors of refractory Mycoplasma pneumoniae pneumonia (RMPP) and their values in early diagnosis. Methods The retrospective analysis of clinical data was conducted in 142 children with Myco-plasma pneumoniae pneumonia (MPP) admitted to Changhai Hospital of Second Military Medical University from Jan. 2012 to Jan. 2014. All children were divided into two groups, RMPP group (n=112) and MPP group (n=30). The comparison was made between two groups in clinical data. The factors were analyzed by the multifactor logistic regression. Results As compared to MPP, RMPP had longer fever duration, the higher ratios of large consolidation shadows, extrapulmonary complications and in-creased CRP level (P<0.05). The results of logistic regression indicated that the clinical risk factors included large consolidation shadows (OR=6.57, 95%CI:2.10-20.56), extrapulmonary complications (OR=11.66, 95%CI:2.42-56.08) and CRP (OR=14.87, 95%CI:2.67-82.79) (P<0.01). Conclusions Large consolidation shadows, extrapulmonary complications and CRP are clinical risk factors of RMPP. CRP elevation and lung imaging changes are valuable in early diagnosis of RMPP.

Discipline evaluation is an effective and boosting mean of constructing high level key disciplines,but if there is something wrong or flaws with the means,indicators,process,ways,the effect may be just the opposite.Therefore,establishing scientific evaluation system is an important premise to construct key disciplines,promote discipline development and improve the level of academy construction.This article which is aimed at current situation of discipline evaluation system,puts forward some major principles to establish scientific evaluation for discipline,it is significant to play a right evaluation guide and promote the discipline construction.Carrying out discipline evaluation needs to have right guiding thought,establish and perfect indicator system of discipline evaluation,strengthen orderly management of evaluation work,offer scope to stimulate function of discipline evaluation.Only in these ways,can we construct a batch of characteristic and competitive key disciplines.