Objective To evaluate the effect of breast-feeding on newborns' pain caused by heel prick. Methods A convenient sample of sixty newborns from a hospital in Beijing undergoing heel prick for the Newborn Screening Program Blood Test were enrolled. They were randomly divided into breast-feeding group and control group. The newborns in the breast-feeding group began to receive breast-feeding at two minutes before the heel prick until 8 minutes after the heel prick finished. The newborns' grimace,cry,heart rate (HR) and oxygen saturation (SaO_2) were recorded and compared between the two groups. Results There were significant differences on the starting time and lasting time of grimace and cry caused by pain,numbers of crying neonates,SaO_2 during and 1 to 4 minutes after heel stick,as well as the recovery time of SaO_2 after heel stick between the two groups (P＜0.05 or P<0.01). Conclusion Breast-feeding can relieve newborns' pain caused by heel prick.

Quality assurance(QA) and Quality Control(QC) of MRI has become very realistic and imperative,which can ensure safety and availability of MRI and improve diagnosis quality.From the practice of the daily grind of MR,the connotation and main content of MR QA and QC are discussed.It is illuminated that MR QA and QC not only should be standardized and systemized,but also needs leaders' recognition and everyone's participation.The responsibility of medical engineers includes emergency maintenance,preventive maintenance,optimization of sequences and parameters,development and application of new techniques Clinical engineers play an irreplaceable and important role in the whole process of MR QA/QC.

The effect and value that are assurance of standard operation in quality control and administration of digital im- ages were discussed. The putting forward concept and aim of standard operation were classified into four grades: best, good, checkout and below standard according to evaluating factors and conditions of standard operation. In order to guarantee the implementation of quality control, medical staff should renew ideas and enhance the consciousness of quality control. The standard operation can be guided and supervised by the director in machine and the system of rewards and penalties can be established. The standard operation has important significance and values, which carry out quality control and quality ad- ministration in medical imaging effectively.

Objective: To improve the database of medical equipment archives system and manage medical equipment more scientifically and efficiently. Methods:According to the needs of medical equipment management, the problems of medical equipment archives system would be analyzed and addressed. Results:In recent medical equipment archives system, the database of usage rate, cost-effectiveness, maintenance costs and property management should be improved. Conclusion:The improved archives system could provide reliable basic data and multi-faceted sharing for medical equipment dynamic management.

Objective To test the key indexes of full-field digital mammography to keep it in good condition.Methods The testing was carried out based on clinical experiences and GBZ 186—2007 Mammography Quality Control Testing Specification.Results The testing items and indexes were proposed to facilitate the staff to check and operate the machine.Conclusion Clinical safety of full-field digital mammography and image quality are both enhanced greatly.

Objective To explore the asymmetry of metabolic products of the auditory cortex in normal human brain after being stimulated by the pure tone with the proton magnetic resonance spectroscopy(1 H-MRS). Methods Twelve healthy volunteers, including 7 males and 5 females, were performed MRS tests before and after the stimulation of the pure tone of 90 dB in intensity and 1000 Hz in frequency. The the metabolites peak of the N-acetylaspartate (NAA) ,creatine(Cr) ,choline( Cho) , glutamine/glutamate ( Glx) and GABA in auditory cortex were investigated, The content of metabolic products were conducted with half-quantitative analysis. The differences of the NAA/( Cho + Cr) ,Glx/Cr and GABA/ Cr ratios before and after pure tone stimulation in the bilateral auditory cortex were analyzed. The difference of distribution of the metabolic products between the left and right auditory cortex was also analyzed to explore the asymmetry of the auditory cortex. Results The NAA/( Cho + Cr) and GABA/Cr ratios increased,the Glx/Cr ratio decreased in the left auditory cortex after being stimulated by the pure tone. There were significant differences in the NAA/( Cho + Cr) , Glx/Cr and GABA/Cr ratios before and after pure tone stimulation (P<0.05) ;the GABA/Cr ratio decreased,the Glx/Cr and NAA/( Cho + Cr) ratios increased in the right auditory cortex after being stimulated by the pure tone, and statistical difference of the GABA/Cr ratio was found before and after pure tone stimulation (P<0. 05) ,however the difference of the Glx/Cr and NAA/(Cho + Cr) ratios before and after pure tone stimulation was not significant (P>0.05). There were statistically significant differences in the Glx/Cr ratio of the auditory cortex between two sides after being stimulated by the pure tone. Conclusion The metabolic lateralization exists in auditory cortex of normal human brain after being stimulated by the pure tone, which may be the bases of the functional asymmetry.

Objective To investigate the effects of ribs in high intensity focused ultrasound (HIFU)beam path on formation of coagulative necrosis in cattle liver in vitro in the same acoustic power. Methods The HIFU ablation was carried out in the manner of a single dot in the liver in vitro. The liver was ablated by HIFU in free field,then the ribs were placed between the focal plane and transducer,directing the beam axis through the intercostals space, lied at the rib edge and on the centre of middle rib. For each of these axial arrangements,the plane of the front surface of ribs was placed 3 cm,6 cm or 9 cm in front of the focus. After HIFU exposure,the tissue necrosis rate(TNR),the maximum length,width,depth and position of the coagulated necrosis in the liver were measured. Results ①The TNR was 100% in the free field. When the ribs were placed 3 cm in front of the focal plane,directing the beam axis through the intercostals space, the TNR was 100%. When directing the beam axis lied at the rib edge and on the centre of middle rib,the TNR decreased sharply. When the ribs were placed 6cm and 9cm in front of the focal plane, the TNR was more than 50%. ②When the ribs were placed in HIFU beam path, the volume of necrosis decreased compared with those in free field. The relationship between the ribs and beam axis, the location of ribs placed away from the focal plane different,the volume,length,width and position of the coagulated necrosis different. ③ When the ribs were close to the focal plane,unacceptable damage could been observed on the surface of ribs.When the ribs were far away from the focal plane, the ribs were safe. Conclusions The volume of necrosis decrease when the ribs are placed in HIFU beam path. The relative location of ribs and HIFU beam axis, the location of ribs away from the focal plane are relative with the volume of the coagulated necrosis. When directing the beam axis through the intercostals space, the volume of necrosis is large, and the shape of coagulated necrosis is regulated. When the ribs are closed with the focal plane,ribs are damaged probably.

With wide range applications of the ultra-large-scale integrated circuits, multilayer circuit board and components surface welding technology, clinical medical engineers have been confronted with challenges in the service and maintenance of largescale medical equipments and the traditional model has faced the great challenges too. The clinical medical engineers should be actively get involved in operation, maintenance and service of large-scale medical equipment, in the same time; it's necessary for buying suitable service supply, protecting the smooth function of large- scale equipment and meets the clinical needs.

As the development of clinical medicine has depended on modern medical equipment increasingly,clinical medical engineers have become the bridges between modern clinical medicine and engineering.They keep the normal running of hospitals and promote the hospital modernization.The equipment service & maintenance isn't the only responsibility of medical engineers.In fact,engineers should be responsible for all medical activities relevant to engineering equipment.The main tasks of engineers should shift from the equipment service & maintenance to the application safety and quality control in the whole process of the equipment usage,which include equipment application safety and risk control,failure service and preventive maintenance,quality control and management,measurement and monitor of adverse event,etc.

Professional features,which include taking students as its main body and improving the students' practical and operational ability as its aim are embodied in microbiology experimental teaching to improve the teaching quality and train high medical talents with different majors.Meanwhile,the design is intended to make medical graduates with different majors to quickly combine the microbiology knowledge with the practical situation in work thus to better serve the society.