The link between micro- and macro-parameters for radiation interactions that take place in living biological systems is described in this paper. Meanwhile recent progress and development in microdosimetry and nanodosimetry are introduced, including the methods to measure and calculate these micro- or nano-parameters. The relationship between radiobiology and physical quantities in microdosimetry and nanodosimetry was presented. Both the current problems on their applications in radiation protection and radiotherapy and the future development direction are proposed.
ObjectiveTo enhance nurses'awareness of pressure ulcer management and reduce the incidence of pressure ulcers by using the risk early warning management idea. MethodsWe analyzed the data of patients with pressure ulcers and patients at high risk of pressure ulcers reported through nursing software between January 2009 and December 2011.Then,we timely and actively gave instructions and formulated corrective measures for the weak points in order to optimize pressure ulcer management process. ResultsNurses'awareness of prevention of pressure ulcers was improved,and the number of patients at high risk of pressure ulcers reported was increased year by year.From 2009 to 2011,the ratio of extremely high-risk and high-risk patients to all discharged patients was respectively 0.76%,1.01% and 0.76%;while from 2009 to 2011,the rate of in-hospital pressure ulcers hard to avoid was respectively 0.06%,0.06% and 0.02%. ConclusionBased on pressure ulcers wound team management,training nurses'early warning management idea,assigning corresponding responsibilities and management goals can help to standardize the management of pressure ulcers and raise the discipline level unceasingly.
ObjectiveTo investigate the distribution and drug resistance of Acinetobacter baumannii (AB) in a women and children's hospital. MethodsStrains of AB isolated from clinical specimens between January 2011 and December 2013 were identified with Vitek2-compact microbiology analyzer; antimicrobial susceptibility test was performed by Kirby-Bauer disk diffusion method. The resistant rate, intermediate rate and susceptibility rate of drugs were calculated according to the criteria in guidelines of Clinical and Laboratory Standards Institute. WHONET 5.6 software was used to analyze the data. ResultsA total of 167 strains of AB were isolated and tested. Neonatal ward had the highest detection proportion. Most strains of AB were isolated from sputum. The drug resistance rate of AB to piperacillin tazobactam, cefepime and carbapenem was<25%. ConclusionThe drug sensitivity rate of AB to piperacillin/tazobactam, cefepime and carbapenems was high, but drug resistence to antimicrobial drugs increased continuously in three years. Medical institutions should strengthen the monitoring of AB resistance, implement rational use of antibiotics, and carry out hand hygiene education, to reduce the generation and dissemination of AB resistant strains.
Light cannot be propagated within the range of photonic crystal band gaps. Based on this unique property, we proposed a method to improve anti-radiation capability through one-dimensional photonic crystal coating. Using transmission matrix method, we determined the appropriate dielectric materials, thickness and periodic numbers of photonic crystals through Matlab programming simulation. Then, compound one-dimensional photonic crystal coating was designed which was of high anti-radiation rate within the range of X-ray. As is shown through simulation experiments, the reflection rate against X-ray was higher than 90 percent, and the desired anti-radiation effect was achieved. Thus, this method is able to help solve the technical problems facing the inorganic lead glass such as thickness, weightiness, costliness, high lead equivalent, low transparency and high cost. This method has won China's national invention patent approval, and the patent number is 201220228549.2.
ObjectiveTo summarize cardiopulmonary bypass (CPB) management experience in tetralogy of Fallot (TOF) infants weighing less than 8 kg. MethodsA total of 120 TOF infants weighing less than 8 kg received surgical repair in Wuhan Union Hospital from July 2009 to August 2013. There were 85 males and 35 females with their age of 1-18 months and body weight of 4-8 kg.The diagnosis of all the patients was made with echocardiography and diagnostic cardiac catheterization. Moderate hypothermia or profoundly hypothermic CPB with low-flow perfusion was used according to different surgical procedures. Imported membrane oxygenators and 4:1 cold blood cardioplegia were used. Zero-balance ultrafiltration during CPB and modified ultrafiltration during rewarming were performed. ResultsCPB time was 65-200 (115.3±9.6) minutes, and aortic cross-clamping time was 40-110 (60.3 ±10.2) minutes. A total of 112 patients received moderate hypothermia and low-or moderate-flow perfusion, and 8 patients received profound hypothermia and low-flow perfusion. Ultrafiltration volume was 780.5±50.3 ml, and hematocrit (HCT) increased to 0.35-0.40 after modified ultrafiltra-tion. Heart beat was automatically recovered in 114 patients (95%) after aortic unclamping. Weaning off CPB was successful in 119 patients, and 1 patient received extracorporeal membrane oxygenation because of difficult weaning from CPB. Postoperative mechanical ventilation time was 26.5±14.5 hours, and length of ICU stay was 121.5±16.5 hours. Five patients died of low cardiac output syndrome, and the other 115 patients were discharged successfully. ConclusionAppropriate hemodilution and colloidal pump priming solutions, perfusion methods suitable with surgical procedures, 4:1 cold blood-potassium cardioplegia, continuous zero-balance ultrafiltration during CPB and modified ultrafiltration during rewarming to maintain reasonable HCT and colloid osmotic pressure are all crucial factors in CPB management for surgical repair of TOF in infants.
Automatic classification of different types of cough plays an important role in clinical. In the previous research of cough classification or cough recognition, traditional Mel frequency cepstrum coefficients (MFCC) which extracts feature mainly from low frequency band is usually used as feature expression. In this paper, by analyzing the distributions of spectral energy of dry/wet cough, it is found that spectral difference of two types of cough exits mainly in middle frequency band and high frequency band. To better reflect the spectral difference of dry cough and wet cough, an improved method of extracting reverse MFCC is proposed. In this method, reverse Mel filter-bank in which filters are allocated in reverse Mel scale is adopted and is improved by placing filters only in the frequency band with high spectral energy. As a result, features are mainly extracted from the frequency band where two types of cough show both high spectral energy and distinguished difference. Detailed process of accessing improved reverse MFCC was introduced and hidden Markov models trained by 60 dry cough and 60 wet cough were used as cough classification model. Classification experiment results for 120 dry cough and 85 wet cough showed that, compared to traditional MFCC, better classification performance was achieved by the proposed method and the total classification accuracy was raised from 89.76% to 93.66%.
This paper discusses the relationship between stimulating pulse width and the threshold of electrically evoked compound action potential (ECAP). Firstly, the rheobase and chronaxy from strength-duration curve of nerve fiber was computed using the shepherd's experiment results. Secondly, based on the relationship between ECAP and the action potential of nerve fiber, a mathematical expression to describe the relationship between stimulating pulse width and ECAP threshold was proposed. Thirdly, the parameters were obtained and the feasibility was proved to the expression with the results of experiment using guinea pigs. Research result showed that with ECAP compared to the action potential of nerve fiber, their threshold function relationship with stimulating pulse width was similar, and rheobase from the former was an order smaller in the magnitude than the latter, but the chronaxy was close to each other. These findings may provide meaningful guidance to clinical ECAP measurement and studying speech processing strategies of cochlear implant.
ObjectiveTo explore the effect of the reimplantation procedure with the De Paulis Valsalva graft in patients with aneurysms. MethodsWe retrospectively analyzed the clinical data of 38 patients underwent valve-sparing aortic root replacement using De Paulis graft in our hospital between September 2005 and July 2013.There were 32 male and 6 female patients at age of 45.5±12.4 years. We compared the parameters of pre-operation and post-operation and followed up the patients for 5 years. ResultsThere were 2(5.3%) deaths in hospital. The follow-up time was 2-95 months with following-up rate of 92.1%(35/38). A total of 2 patients(5.3%) had grade 3 to grade 4 aortic insufficiency. And one of these patients received aortic valve replacement after 1 year. At 5 years of following-up, one patient died of septic shock due to pacemaker infection. One patient died of kidney failure due to renal artery dissection aneurysm affected with impaired renal function and long-term hemodialysis. ConclusionThe reimplantation type of valve-sparing procedure can be facilitated by the use of the De Paulis valsalva graft and can be performed with satisfactory perioperative and mid-term results.
ObjectiveTo explore the difference between minimally invasive direct and conventional thoracotomy off-pump coronary artery bypass surgery (CABG). MethodsWe selected 276 patients underwent off-pump CABG surgery in our hospital from June 2005 through June 2014. There were 55 patients with minimally invasive off-pump CABG surgery and 221 patients conventional thoracotomy surgery. By using the method of peopensity score matching, we selected 55 conventional thoracotomy patients as a control group in our study. There were 41 males and 14 females at age of 60.8±10.5 years with minimally invasive off-pump CABG surgery, 44 males and 11 females at age of 60.6±12.5 years with conventional thoracotomy. ResultsThere was no statistical difference in surgery time, stay in the intensive care unit (ICU) time between conventional thoracotomy surgery and minimally invasive off-pump CABG. Compared with conventional thoracotomy surgery, minimally invasive off-pump CABG patients had statistical improvement in post-operative hospital stay time (7.3±3.1 d vs. 8.8±3.9 d, P=0.01), postoperative drainage (684(0-2 790)ml vs. 739(50-4 460)ml, P=0.03), perioperative blood transfusion (1.91(0-20)U vs. 6.62(0-20)U, P=0.00), surgery incision length (5.6±1.1 cm vs. 26.3±4.5 cm, P=0.00). ConclusionOverlooking the learning curve, minimally invasive direct off-pump CABG surgery has more advantages than conventional thoracotomy surgery. It is a safe and effective procedure.
ObjectiveTo summary the safety and efficiency of the minimally invasive direct cardiac surgery (MIDCS) approach in elderly patients with heart disease. MethodsWe retrospectively analyzed the clinical data of 60 patients underwent MIDCS in Beijng Anzhen Hospital between April 2010 and January 2013. There were 34 males and 26 females with mean age of 66.4±4.8 years and mean weight of 66.1±10.6 kg. ResultsMean cardiopulmonary bypass time and aortic cross-clamp time was 141.2±57.2 minutes and 99.8±37.6 minutes respectively. A total of 37 patients (90.2%) recovered to beat automatically after heart ceased operation. Median mechanical ventilation time was 17.1±9.1 hours. Mean intensive care unit stay was 22.1±12.2 hours. Mean post operative hospital stay was 7.0±2.5 days. Mean incision length was 5.3±0.9 cm. Mean pericardial draining volume was 466.6±412.1 ml in the first day after operation. No transfusion occurred in 27 (45.0%) patients. Early postoperative mortality was 3.3% (2/60). There were 2 patients of reexplorations for bleeding, 1 patient of the twice tracheal intubation, 1 patient of cardiac arrest after operation, 2 patients of poor healing of skin incision, and 1 patient of injury of right phrenic nerve. When leaving hospital, 47 patients were in heart functional class Ⅰ, 8 patients in class Ⅱ, and 3 patients in class Ⅲ. ConclusionMIDCS is associated with good operative effect in the near future with superior safety and broad application range in elderly patients with heart disease.