Objective:According to our use of ELEKTA Precise(105753) the overall operation of accelerator operation and equipment failure occurred in the process of ten years are analyzed and summarized, and discuss the regular running and how to improve the efficiency.Methods:We will ELEKTA Precise(105753) state of accelerator operation failure ten years once the phenomenon, has carried on the system summary, analysis and classification.Results: Based on the ELEKTA Precise(105753) summarizes the fault system, Our accelerator rate was higher in the early stage of fault and operation for more than eight years in clinical use, relatively high failure rate is one of the mechanical parts and the high voltage part.Conclusion: To ensure the normal operation of the accelerator, the most effective way to improve the utilization ratio of the equipment on the use and maintenance of scientific management, reasonable; only the norms of medical accelerator and other large medical equipment repair, maintenance and accelerator QA/QC process, it can improve operation rate accelerator, so as to enhance the comprehensive status of tumor radiotherapy accelerator in full.

According to the deficiencies of the present treatment planning systems,a research of field size dosage calculation based on two-dimensional localization image is presented.The technologies are emphasized including coordinate transformation,image preprocessing,edge detection & extraction and field size dosage calculation,etc.

Pulmonary surfactant is a complex mixture of lipoproteins synthesized,secreted and recy-cled by type Ⅱ alveolar cells. The primary function of PS is to minimize the surface tension at the alveolar air-liquid interface. Surfactant dysfunction with quantitative and qualitative abnormalities of both phospholipids and proteins are characteristics of patients with acute respiratory distress syndrome ( ARDS ) . Exogenous surfactant replacement shows consistent improvements in gas exchange,but had limited success in improving survival. These may be due to variety of aetiologies in ARDS、surfactant compositiones, delivery methods, optimal time and doses. At this time,surfactant therapy cannot be recommended as routine therapy in pediatric ARDS.

ObjectiveTo assess the effects of dopamine,dobutamine and norepinephrine on the P(g-a)CO2 and superior mesenteric blood flow in septic shock.MethodsRabbit septic shock model was established by challenging with intravenous injection of lipopolysaccharides from Escherichia coil(2 mg/kg).The rabbits with septic shock were randomly assigned to 3 groups-dopamine group(n = 8),dobutamine group(n = 8) and norepinephrine group(n = 8).Apart from volume resuscitation with normal saline solution [20 ml/(kg· h)]，dopamine[5μg/(kg·min)],dobutamine[(5μg/(kg·min)]and norepinephrine [(1μg/(kg·min)]were infused in dopamine group,dobutamine group and norepinephrine group respeclively.Cardiac index(CI) and superior mesenteric blood flow index(SMBFI) were continuously monitored by doppler flowrneter.Gastric mucosal PCO2 was evaluated by gas tonometry every 10 min.Arterial and venous blood gas analyses and lactate levels were measured every 1 h.ResultsMAP,CI,and SMBFI significandy decreased and P(g-a) CO2 increased after lipopolysaccharides infusion in three groups.After 2-hour treatment,MAP in norepinephrine group[(70 +3) mm Hg]was higher than that of dopamine group[(66±4) mm Hg]and dobutamine group[(65±4) mm Hg](P ＜0.05).SMBFI in norepinephrine group [(18.7±2.9) ml/(kg·min)]was higher than that of dopamine group[(16.2±1.6) ml/(kg·min)]and dobutamine group[(15.8±1.9) ml/(kg·min)](P＜0.05).P(g-a) CO2 in norepinephrine group [(30±6) mm Hg]was lower than that of dobutamine group[(23±5)mm Hg](P＜0.05).Condnsion As an adjuvant therapy of volume resuscitation,norepinephrine is more effective than low dose dopamine and dobutamine in improving splanchnic perfusion.

AIM:To observe the influence of high expression of miR-15a-5p on the proliferation and migration of human hepatocellular carcinoma SMMC-7721 cells.METHODS: The miR-15a-5p oligonucleotide , which was recon-structed with additional restriction sites of EcoRⅠand HindⅢ, was chemically synthesized and confirmed by sequencing . The miR-15a-5p eukaryotic expression system was constructed by pcDNA 6.2-GW/Em-GFP-pre-miR-15a-5p plasmid.The miR-15a-5p was transfected into the SMMC-7721 cells transiently by plasmid , and quantified by quantitative real-time PCR at the mRNA level.The cell viability was measured by CCK-8 assay, and the living cell counting was performed by the method of Trypan blue exclusion .The migration ability of the SMMC-7721 cells with high expression of miR-15a-5p was de-tected by wound healing test .RESULTS: The sequence of miR-15a-5p oligonucleotide 100% matched the designed se-quence.Compared with control group , the miR-15a-5p expression was increased significantly (P<0.05).The viability, the living cell number and the migration ability of the SMMC-7721 cells were decreased in high expression of miR-15a-5p group with statistically significant difference (P<0.05).CONCLUSION: The abilities of proliferation and migration in human hepatocellular carcinoma SMMC-7721 cells are decreased by high expression of miR-15a-5p.

Objective To investigate the incidence,etiology and risk factors of cardiorespiratory arrest (CRA) in pediatric emergency room and preliminarily evaluate the efficacy of cardiopulmonary resuscitation (CPR).Methods The unified,standard in-hospital Utstein style was used for data collection with filling answers in the questionnaire.The survey items included the causes of cardiorespiratory arrest and the factors influencing the efficacy of CPR.The restoration of spontaneous circulation (ROSC) was used to evaluate short-term efficacy of CPR.Results Totally 182 380 patients aged from 28 days to 18 years were admitted to emergency room of Beijing Children' s Hospital between July 1,2008 and February 28,2010.Of them,237 patients (0.13％) were subjected to cardiorespiratory arrest,of which 169 patients received CPR and 88 patients (52.1％) got sustained ROSC.Neither sex nor age distribution affected ROSC.The primary cause of CRA and kind of initial abnormal rhythm of heartbeat leading to CRA were associated with the rate of ROSC.The rates of ROSC occurred in patients with or without pre-hospital transport were 64.1％ and 44.8％,respectively.The rate of ROSC was closely related to time consumed for getting ROSC by CPR,and as CPR durations were ≤ 10 min,10 to 30 min,and ＞ 30 min,the rates of ROSC were 67.5％,61.4％ and 30.5％,respectively.Multiple stepwise logistic regression analysis showed that kind of initial abnormal rhythm and CPR duration were associated with the rate of ROSC.Conclusions The incidence of CRA in emergency was 0.13％,and the rate of ROSC after CPR was 52.1％.The kind of initial abnormal rhythm of heartbeat and CPR duration were independent factors associated with the rate of ROSC.

Objective To study the clinical features of invasive pneumococcus disease (IPD) with resistance to antimicrobial agents in children,and to improve the diagnosis and treatment of this disease.Methods The clinical data from 21 IPD patients younger than 13 years old were collected from January 2008 through December 2010 in Pediatric Intensive Care Unit in Beijing Children's Hospital for retrospective analysis. Specimens of blood,pleural effusion,cerebrospinal fluid and soft tissue aspirated were collected from these children,and 23 strains of streptococcus pneumonia (SP) were cultured,isolated and confirmed,and the antibiotics susceptibility to penicillin and other antibiotics of these strains were assayed.Results Among the 21 IPD children,the ratio of male to female was 0.9∶1,and the age was 5 months to 13 years,with 61.9％ of them under 2 years.Of them,12 patients (57.1％ ) had purulent pleurisy,and 1 (4.8％ )patient had an underlying disease diagnosed to be X - linked agammaglobulinemia (XLA).There was no seasonal difference in the occurrence rate of this disease. Eight (38.1％) patients were cured,11(52.4％ ) were improved,while 2 (9.5％ ) patients not improved without death.There was no statistically significant difference in the annual detection rate of invasive SP (x2 =3.711,P =0.156).The incidences of penicillin-intermediate susceptibility SP (PISP) and penicillin-resistant SP (PRSP) were 47.8％ and 26.1％ respectively.The rate of resistance to multiple antibiotics was 91.3％.Conclusions Children aged less than 5 years,especially younger than 2 years,are prone to IPD,and purulent pleurisy and septicemia are often seen in this disease. Some patients had the underlying diseases.The complications included hemophagocytic syndrome,acute respiratory distress syndrome,septic shock,bronchial pleural fistula and so on.The multidrug resistance rate was 91.3％.It is important to put great emphasis on the monitoring antibiotics resistance to invasive pneumococcal disease.

Objective To analyze the epidemiologic characteristics and risk factors for mortality in non-(human immunodeficiency virus,HIV) infected children with pneumocystis carinii pneumonia(PCP). Methods The data of non-HIV infected children with PCP diagnosed in Beijing Children′s Hospital from January 1,2006 to December 31,2012 were collected. They were divided into survival and non-survival group according to the prognosis. The epidemiologic characteristics and risk factors for mortality were analyzed. Results Sixteen patients were enrolled in this study. Ten of them survived and 6 of them were non-survived. The basic diseases included malignant tumor in 5 patients and non-malignancy diseases in 11 of them. Com-pared with the survival group,the non-survival group had a higher average age [(12. 00 ± 2. 00) years vs. (6. 65 ± 4. 32)years,P=0. 01],higher ratio to need mechanical ventilation (6/6 vs. 4/10,P=0. 04),lower PaO2/FiO2[(73. 88 ±26. 95) mmHg vs. (167. 50 ± 97. 17) mmHg,1 mmHg=0. 133 kPa,P=0. 01] and lower pediatric critical illness score(75. 67 ± 5. 72 vs. 86. 40 ± 8. 88,P=0. 02). There were no differences on sex ratio,kinds of basic diseases,whether with co-infections,the time of immunosuppressant administration, the time from onset to diagnosis,the time from onset to beginning trimethoprim-sulfamethoxazole therapy, PaCO2 ,white blood cell counts,lymphocyte counts,CD4+ cell counts,C-reactive protein,and hemoglobin con-centrations between the survival and non-survival group. Conclusion A higher age, need for mechanical ventilation,lower PaO2/FiO2 and lower pediatric critical illness score were risk factors for mortality in non-HIV infected children with PCP.

Carcinoma ; diagnosis ; Granuloma, Plasma Cell ; diagnosis ; Humans ; Laryngeal Neoplasms ; diagnosis ; Larynx ; pathology

Objective To compare the diagnostic performance of prospective electrocardiogram (ECG)-gating 320-detectorcomputed tomography coronary angiography (CTCA) versus retrospective ECG-gating CTCA. Methods 500consecutive patients suspected coronary artery disease with heart rate of less than 65 bpm were performed coronary computed tomography angiography (CCTA) with prospective (group P)and retrospective (group R) ECG gating in turn. The image quality was divided into four levels. Success rates, effective radiation dose,image quality and diagnosis were evaluated. Results Success rates of examination in group P and R are100%.Mean patient radiation dose was significantly different in group P (3.28±1mSv) and R(14.36 ±2.3 mSv).131 and 142 of 3750 segments (250 patients x 15 segments per patient) were too small(1.5mm)tobe characterized in group P and R. 96. 51% (3619/3750) and 96.12% (3608/3750) characterized segments were not significantly different in group P and R. 95.09% segments received a score of 4 and 1.09% segments received a score of 3 in group P, while 95.23% and 0.74% in group R.The cause of 2 and 3 points in the two groups was motion artifact. Stair-step artifacts and images scored as 1were not found.Compared with CAG,the sensitivity,specificity,false positive andfalse negative value in group P(86. 49% ,98. 70% ,88. 89% ,98.38%) and R(83. 87% ,98.74% ,89. 65%,97.93%) were not significantly different. Conclusion Although the patient radiation exposure was significantly lower, the diagnostic performance of prospective ECG-gating 320-detector CTCA was comparable with that of retrospective ECG-gating 320-detector CTCA on patients with stable heart rates less than 65 bpm.