Objective:To study the sintering character of calcium-deficient apatite.Methods:Calcium-deficient apatite synthesised by wet chemical method was sintered at different temperature and then its chemical composition, phase structure and morphology were examined by FT-IR spectroscopy, X-ray diffraction (XRD) and field emission scanning microscopy (FESEM) respectively.Results:When the heating temperature is below 500 ℃, apatite crystal kept a stable size with a diameter of 12-26 nm and a length of 30-66 nm. After sintered at 600 ℃ for 2 h, apatite crystal were with a diameter of 25-40 nm and a length of 75-100 nm. Around 800 ℃ for 2 h, apatite was decomposed into Ca_3(PO_4)_2.The crystal size of the Ca_3(PO_4)_2 surpassed 200 nm in diameter and length. NH_4+ ion could be removed at temperature beyond 300 ℃.Conclusion: Calcium-deficient apatite has it's specific sintering character.

0.05). The cells on Ti1 and Ti2 were attached well till confluent.Conclusion:The neotype titanium alloys are biocompatible.

Objective To discover the value of endoscopi c ultrasonography (EUS) in predicting the resectability of pancreatic carcinoma.Methods Thirty-eight consecutive patients were prospectively i nvestigated using EUS to determine the tumor resectability. Two specialists eval uated the EUS findings in each of the patients prospectively. All patients were explored and their resectability noted. In the meantime, we compared the accurac y of EUS diagnosis with that of CT, MRI and sonography respectively.Results Ten out of 38 cases with pancreatic carcinoma were cons idered to be resectable by EUS with a positive predictive value of 80 0% in com parison with surgical findings. EUS also had high correlation with surgical resu lts in assessing un-resectability of pancreatic carcinoma, the negative predic tive value is 96 4%. There was 1 false negative and 2 false-positive assessmen ts (sensitivity, 88 9% and specificity, 93 1%). The accuracy of EUS was the hi ghest. The diagnostic accuracy of EUS, CT, MRI and sonography were 97 4%, 94 6 %, 89 5% and 73 7% respectively.Conclusion It is an effective method to use endoscopic ultrason ography in predicting the resectability of pancreatic carcinoma before operation .

BACKGROUND:Monofocal intraocular lens can restore distant vision of cataract patients, butit is not suitable fornear vision recovery, so most ofpatientsstil need to wear glasses. In contrast, multifocal intraocular lens can make up for the shortcomings of the single lenstoim provenear vision and increase the rate oftaking off the spectacles.
OBJECTIVE:To compare the visual function of senile cataract patients after aspheric multifocal and monofocal intraocular lens implantation.
METHODS:Totaly 30 senile cataract patients with 50 affected eyes were randomly divided into two groups: the eyes were implanted with aspheric multifocal and monofocal intraocular lens as experimental group and control group, respectively. At 3 months after implantation, distance visual acuity at a distance of 5 m, the best corrected distance visual acuity,as wel asnear and intermediate visual acuity at a distance of 30, 60 and 100 cm were detected, respectively. Besides, contrast sensitivity at a spatial frequency of 0.8, 1.5, 6 and 18 cpd under light and dark environment was measured.
RESULTS AND CONCLUSION:At 3 months after implantation, the distance visual acuity at a distance of 5 m in the two groups was significantly better than that before surgery (P< 0.05); no significant differences were found in near and intermediate visual acuitiesat a distance of 5 m and 100 cm between two groups, but the near visual acuitiesat a distance of 30 and 60 cm in the experimental group were significantly higher than those in the control group (P< 0.05). In addition, the contrast sensitivity at different spatial frequencies under light environment had no significant differences between two groups; and compared with the control group, contrast sensitivity at the frequency of 6 cpd under dark environment was significantly decreased in the experimental group (P< 0.05), but no significant differences were found in the other spatial frequencies. These results show that aspheric multifocal intraocular lens can significantly improve the near and intermediate visual acuity of senile cataract patients compared with the monofocal lens.

Objective To strengthen the scientific management of automatic processor and promote QC, based on analyzing QC management chart for automatic processor by statistical method, evaluating and interpreting the data and trend of the chart. Methods Speed, contrast, minimum density of step wedge of film strip were measured everyday and recorded on the QC chart. Mean ( ), standard deviation ( s ) and range(R) were calculated. The data and the working trend were evaluated and interpreted for management decisions. Results Using relative frequency distribution curve constructed by measured data, we can judge whether it is a symmetric bell shaped curve or not. If not, it indicates a few extremes overstepping control limits possibly are pulling the curve to the left or right. If it is a normal distribution, standard deviation( s ) is observed. When ?2s lies in upper and lower control limits of relative performance indexes, it indicates the processor works in stable status in this period. Conclusion Guided by statistical method, QC work becomes more scientific and quantified. We can deepen understanding and application of the trend chart, and improve the quality management to a new step.

Objective To construct a lentivirus vector for RNA interference targeting myosin Va gene and to observe its effect on motility and migration of human pulmonary giant cell carcinoma PG cells. Methods Based on the efficient target sequence for myosin Va RNAi, two pairs of oligo DNA containing myosin Va RNAi target sequence or scramble sequence were synthesized and inserted into pSuper vector, followed by sequence analysis. The expressing cassette H1 promoter-shM5A/shCON from the recombinant pSuper plasmid was then transferred to the lentivirus vector plenti4, and the recombinant lentivirus was packaged. PG cells were transduced with the packaged lentivirus and the positive cells were screened by zeocin selection. RT-PCR was performed to determine the myosin Va RNAi efficiency in zeocin-resistant PG cells, and wounding assay and Boyden chamber assay were utilized to examine the capabilities of motility and migration in myosin Va RNAi PG cells. Results Restriction enzyme digestion and sequencing confirmed the successful construction of the lentivirus vector containing myosin Va RNAi target or scramble sequence. RT-PCR result showed that myosin Va mRNA levels were remarkably reduced in lentivirus-based myosin Va RNAi PG cells. The abilities of motility and migration were also significantly inhibited in lentivirus-based myosin Va RNAi PG cells, as demonstrated in wounding assay and Boyden chamber assay.Conclusion Myosin Va RNAi lentivirus vector was successfully constructed and efficiently repressed myosin Va expression in PG cells. Repression of myosin Va by RNAi led to the inhibition of PG cells motility and migration, indicating that there might exist correlation between the expression of myosin Va and cancer progression.

Objective: To analyze the curative effect of phacoemulsification and to intraocular lens implantation combined with anterior vitrectomy in the children with congenital cataract, and to investigate its effectiveness and security. Methods: A total of 43 cases (49 eyes) of 3-7 years old congenital cataract children who were admitted to our hospital were selected as the subjects. According to different treatment methods, the children were divided into control group (23 cases with 26 eyes) and treatment group (20 cases with 23 eyes). The children in control group were treated with phacoemulsification and intraocular lens implantation and the children in treatment group were treated with phacoemulsification, intraocular lens implantation and anterior vitrectomy. After operation, the vision of the children in two groups was observed; the intraocular pressure (IOP), anterior chamber depth, posterior capsule turbidity and the complications in operation and after operation of the children in two groups were detected by non-contact tonometer and ultrasonic biological microscope. Results: The children in two groups were followed up for an average of 12 months after surgery, and 49 eyes were follow-up after operation. Compared with control group, the vision of the children in treatment group was improved significantly, and the constituent ratio of the children with corrected visual acuity after opertion≥O. 5 was significantly increased (P<0. 05); the anterior chamber depths was significantly increased (P<0. 05) and the posterior capsular opacity was significantly reduced (P<0. 05). There were no significant differences in the incidences of IOP, corneal endothelium edema (CE), anterior chamber flash (ACF), and anterior chamber cellulosic exudation (ACCE) of the children in two groups (P>0. 05). Conclusion: Phacoemulsification and intraocular lens implantation combined with anterior vitrectomy in the children with congenital cataract can effectively improve the visual acuity, anterior chamber depth and posterior capsule opacity; it is more helpful for the reconstruction of visual function after operation in the children.

Objective:To explore the effects of scout scanning parameters (projection angle and tube potential) on image quality and radiation dose in chest CT and to provide guidance for the selection of scanning parameters in clinical practice.Methods:Different parameter combinations were selected to acquire the scout view of the anthropomorphic adult chest phantom. Fifteen scout views were obtained under parameter combinations of the projection angle (0/90/180 degrees), tube potential (70/80/100/120/140 kV) and tube current (25 mA). And then, chest spiral scans were performed according to the scout views. The other parameters were Assist kV, smart mA (maximum range), 80 mm detector width, 0.992∶1 pitch, 0.5 s rotation time, 330 mm scanning length, 5 mm thickness, NI (noise index) 10. The radiation dose modulation index (ASiR-V) was 30%, and the iterative level was 50%. Volume CT dose index (CTDI vol) and tube current at 4 body levels (pulmonary apex, trachea bifurcation, mammary level and diaphragmatic dome) were recorded. The thermoluminescent dosimeters (TLDs) were used to measure the organ dose of the breast glandular. Regions of interest (ROIs)were selected at the trachea bifurcation and diaphragmatic dome to calculate the contrast noise ratio (CNR). Results:The tube potential of the spiral scanning was automatically selected as 80 kV when the projection angle was 0 degree. The changing of the tube potential for the scout had little influence on the tube current at the four body levels, and the variation range was 0-2% (5/230). The tube potential in the spiral scanning was automatically selected as 100 kV when the projection angles were 90 and 180 degrees. The changing of the tube potential for the scout had a great influence on the tube current at the slice of trachea bifurcation and the variation range was from 14%(29/210)to 44%(93/210). According to the angle projection, there were statistical differences in CTDI vol( P< 0.017), organ dose of the breast glandular, and CNR at the slices of trachea bifurcation and at diaphragmatic dome ( F=13.027, 24.727, 10.630, P< 0.05). According to the tube potential in the scout scanning, there were no significant differences in CTDI vol, organ dose of the breast glandular and CNR at both levels ( P> 0.05). Conclusions:In chest CT, the influence of the projection angle in scout scanning on the image quality and radiation dose was more significant than that of the tube potential.

Objective To explore the clinical diagnosis and management of hepatecellular adenoma(HA). Methods Seventeen HA cases treated in our hospital from Janurary 1986 to June 2007 were studied retrospectively.The clinical and pathologic data were reviewed. Results Of 17 patients,9 were male and 8 were female with median age of 46 years.None of the female patients had a history of oral contraceptives.Most patients were agymptomatic.Preoperative liver function test and AFP serum test were normal.Preoperative imaging study yielded deftnite diagnosis in only a fraction of patients.All 17 cases underwent surgical resection and the postoperative course is uneventful.All cases were followed up ranging from 6 to 252 months.Recurrence was not found.Pathology reported atypical hyperplagia in 2 cases and with malignant transformation in 1 case. Conclusions The diagnosis of HA is exclusive and dependent on clinical data,laboratory test and radiography.HA has a tendency to malignancy.Surgery is recommended in all cases.

Objective To prospectively evaluate the value of US,MSCT,EUS and MRI in the quantitative evaluation of the extent of pancreaticobiliary duct obstruction in pancreatic cancer.Methods Consecutive 68 patients with pancreatic carcinoma underwent US,MSCT,EUS and MRI before surgery.The diameter of extrahepatic bile duct and pancreatic duet were measured,and correlation analysis was performed with surgical specimens.Results Diameters of extrahepatic bile duct scaled by US.MSCT,EUS and MRI were(16.60±6.33)mm,(18.90±6.74)mm,(18.80±5.88)nun and(17.26±4.83)mm,and diameter measured from surgical specimens was(18.39±6.05)mm;the correlation among the four imaging examinations and the surgical evaluation were r=0.3839,P=0.1055;r=0.7113,P=0.0011; r=0.3759,P=0.0465;r=0.3376,P=0.2872,respectively. Kappa Values were 0.6285,0.7115,0.6661 and 0.7490,respectively.The diameter of pancreatic duct was(15.90±3.41)mm,(6.83 4-3.70)mm,(6.77±3.22)mm and(5.58±2.65)mm,and diameter measured from surgical specimens was(5.97±2.60)mm,the correlation among the four imaging examinations and the surgical evaluation were r=0.3584,P=0.2895;r=0.6148,P＜0.0001; r=0.7373,P＜0.0001;r=1.0746,P＜0.0001.Kappa values were 4.159,9.094,9.001 and 4.050.All of these parameters were in coherence with surgical findings.Condusions US could be used as the initial method in the assessment of extrahepatic and pancreatic duct obstruction.MRI and MSCT,combined with EUS if necessary,could be used to quantitatively evaluate the extent of pancreaticobiliary obstruction.