Purpose:To analyse the X-ray stereotactic treatment process during which errors induced and to establish a QA program and its checking frequency.Materials and Methods: Checking the parallelism and the asymmetry of the opposing plates containing localizing wires of the CT(MRI) stereotactic localizing frame; Checking the precision of the mechanical scaler of the target positioner; The influence of the laser alignment system in the treatment room of linear accelerator ; Determining the overall precisions available by a X-ray stereotactic treatment system; and small beam's data acquisition means, etc.Results: An overall target positions'precisions of 2.4mm,2.6mm(1mm CT slice thickness), and 3.7mm, 3.8mm (3mm CT slice thickness) for single and fractionated X-ray stereotactic irradiation respectively can be achieved if a QA program be seriously carried out.Conclusion: It is an essential to establish a comprehensive QA program to guarantee a good treatment precision of X-ray stereotactic irradiation.

Purpose: To analyze factors which influence the precision & accuracy of target positions in Alderson Head phantom and(or) patients.Materials and Methods: A target position simulator was used to determine the precision and accuracy of target localization while Alderson head phantom used to determine the overall precision and accuracy through the treatment procedure.Results: The overall precision and accuracy through the treatment procedure was found to be 1.72?0.60mm, and its contribution from CT localizing step, which was 1.4?0.3mm。Conclusion: Since there are more factors related to patients' treatment, the precision and accuracy of simulating in Alderson phantom is the best estimate for patient treatment.

Corydalis yanhusuo W. T. Wang ex Z. Y. Su et C. Y. Wu is an aperennial herb which grous wild in Anhui Province. The tuber of the plants is used as an anodyne. Cultivation of the plant with seeds obtained from the wild was carried out in our nursery breeding house. Results showed that the emergence rate depends upon the size and ripeness of the seed. Although it is a dicotyledon,yet its seedling showed only a single cotyledon. Secretary tissues could be found in its cuticular layer. Cambium was well developed but both xylem and phleom were not well developed

Genomic imprinting plays a fundamental role in mammal fetal growth and behavior. Abnormal expression of imprinted genes is associated with some genetic diseases and cancers. Imprinted insulin-like growth factor 2 (IGF-2) controls fetal growth by regulating nutrient transportation in placenta. Paternal uniparental disomy, duplication of paternal allele and loss of imprinting are 3 molecular mechanisms of IGF-2 overexpression that can cause Beckwith-Weidemann’s syndrome (BWS). Some assisted reproductive techniques may cause some epigenetic changes that affect embryonic and postnatal development.

Purpose:To analyse the dosimetric parameters measured by the silicon diode, and to describe the features of the dose distributions for small fields.Materials and Methods:P-type silicon diode with small volune and high sensitivity was chosen to measure the PDD,OAR and Sc,p at isocenter for circular fields of 5mm ～50mm in diameter used for stereotactic irradiation .The dosimetric data measured are evaluated by comparising with ones by other methods, such as ionization chamber and films,and ones in literature.Results:The values PDD of 10 and 30 fields at depth from 5cm～20cm are almost the same as those in reference 7 within ?0.6; The effective linear attenuation coefficient extrapolated to zero fiels size is 0.0510cm -1 for 6MV-X rays. The Sc,p value measured by diode and chamber(NE2571) are agread each other within variations of ?0.4% for large field size, but a great difference appears when the field size is 2 times smaller than the diameter of chamber. The Sc,p values by diode for field size of 12.5mm～27.5mm are agreed well with the results by Monte Carlo calculations. The OARs measured by diode are ageed well within 1mm with ones by films developed by ourself. The penumbras(90%～10%) measured by diode are coincidence with the results published.Conclusion:Due to the high dose gradients at the beam edge and the absence of lateral electron equilibrium for the smaller fields, the detector size and positioning are the most impostant factors influenced the measured results. Our practice shows that the silicon diode with diameter of 2mm or smaller is the best choice for the dosimetric date collection for beams used in X-ray stereotactic irradiation.

Objective To further master the Oncomelania hupensis snail situation in Huizhou District,so as to provide the ev-idence for improving the prevention and control work. Methods According to the prevalence of schistosomiasis in history and the characteristics of residual snail points in recent years,the snail surveys were carried out with the environmental sampling and sys-tematic sampling method in history snail environments and their surrounding suspicious environments. Results Totally 5 298 940 m2 in 12 administrative villages of 3 townships were investigated and there were 24 406 m2 snail areas at 5 remaining snail spots in 4 administrative villages. The highest snail density was 283 snails/0.1 m2,and the average density of living snails was 2.31 snails/0.1 m2. A total of 4 303 snails were captured,1 534 were checked by microscopy,and no infected snails were found. Conclu-sion The snail situation is still not stable in Huizhou District,and the monitoring of snail situation still need to be strengthened.

Objective To explore the curative effect of endoscopic simple maxillary ostium enlargement in the treatment of non-invasive mycosis of maxillary sinus. Methods Clinical data of 16 cases of noninvasive mycosis of maxillary sinus were analyzed retrospectively. Results The operation time was 30～120 minutes, with a mean of 60 minutes. No operative complications occurred. The hospital stay was 5～7 days, with a mean of 6 days. Histopathological examination found hyphae and spores in 16 cases, and a positive culture of Aspergillus was observed in 9 cases. Postoperative follow-up for 3～24 months (mean, 18 months) in 16 cases revealed free of symptoms in 14 cases, in which the endoscopic examination showed unobstructed ostium and normal sinusal mucosa, and recurrence in 2 cases, who underwent repeated enlargement of ostium and were re-followed for 6 and 13 months, respectively, without recurrence. Conclusions Nasal endoscopic simple maxillary ostium enlargement in the treatment of non-invasive mycosis of maxillary sinus is a radical and minimally invasive technique, but particular attention must be directed to managing the maxillary ostium.

Objective To investigate advantages of sep to plasty under nasal endoscope. Methods Septoplasty was carried out under nasal endoscope in 50 cases, including 6 cases of upper or posterior n asal septum deviation. Results The operation was completed on one session in all the 50 cases, with the deviated nasal septum being entirely c orrected. The operation time was 30~72 min (mean, 48 min). Follow-up surveys for 6~9 months (mean, 7.1 months) indicated a complete cure in 45 cases (90%) and a n improvement in 5 cases (10%). No septal hematoma, abscess, perforation, nasal cavity adhesion, or bridge collapse were encountered. Conclusions Nasal endoscopic septoplasty has advantages of short operation time, few bl ood loss, mild pain, little complications, and the possibility of nasal sinus co -operation. This technique may fully replace the traditional submucous resection .

Objective To test the performance of the field digital oral medical vehicles(two chairs) developed by School of Stomatology,the Fourth Military Medical University.Methods The field digital oral medical vehicle was developed by using dental health care system,diagnostic imaging systems,oral endoscopic systems,infection control systems,digital management system,the sewage treatment system,temperature conditioning systems,power generation systems,automotive GPS positioning system and other systems.Results The vehicle was characteristized by reliable performance,high degree of functional serialization,complete medical facilities and good operability of the internal layout.Conclusion Its functions fully meet the requirements in field oral disease prevention and control as well as first aid.

Objective To investigate the curative effect of tube placement and drug irrigation in the auditory tube under nasoscope in the treatment of secretory otitis media(SOM). Methods Under the visualization of a 30? nasoscope,an epidural guiding tube was placed through the pharyngeal opening of the auditory tube into the tympanic cavity for drug irrigation in 50 cases of secretory otitis media(50 ears).Results Follow-up observations for 6~24 months showed 26 cases of cure(52%),19 cases of improvement(38%),and 5 cases of no effect(10%),the total effective rate being 90%. Conclusions This procedure has advantages of simplicity of performance,unaffected drum membrane,high safety,no pain,and satisfactory outcomes,being an effective treatment option for improving the function of the auditory tube and hearing ability in patients with secretory otitis media.