BACKGROUND:Studies have confirmed that the surface treatment methods such as silane coupling agent and sand blasting could improve bonding strength of zirconia ceramics and resin binder. In addition, the increase of micro cracks on the surface of zirconia ceramics can also improve the bonding strength of zirconia ceramics and resin binder. But there is a lack of related studies addressing whether repeatedly sintering would have an impact on shear bond strength of zirconia ceramics.
OBJECTIVE:To determine the effect of decorative porcelain temperature firing on the shear bond strength between dental zirconia ceramics and resin binder.
METHODS:Twenty pieces of zirconia ceramics specimens were selected from 40 tablets, and then randomly divided into five groups according to the number of sintered times:control group (without sintering), sintering groups for 2, 4, 6, 8 times. Heat starting temperature was 500 ℃, and final temperature was 1 000 ℃ with a heating rate of 55 ℃/min. The vacuum time was 7 minutes. During the sintering, the final temperature was constant. Unsintered ceramic pieces were bonded using resin binder. Universal testing machine was used to test the shear strength of the interface between the two pieces of zirconia ceramics. The interface after shearing was characterized by scanning electron microscope.
RESULTS AND CONCLUSION:The shear strength of sintering groups for 4, 6, 8 times was significantly higher than that of the control group (P<0.05). Shear strength of specimens sintered twice was slightly higher than that of specimens without sintering, but the difference was not significant (P>0.05). Shear strength of specimens sintered 8 times was slightly higher than that sintered 4 and 6 times (P<0.05). Under the scanning electron microscope, there was no crack on the surface of non-sintered zirconia ceramics. After 2 times sintering, the surface appeared to have fine cracks. After sintering 4 times, visible cracks were increased. After six rounds of sintering, the surface began to have significant changes;cracks rose along with slight gaps and a smal amount of adhesive residues were found. After sintering for 8 times, cracks and voids were obviously increased on the sintered surface and adhesive residues were found. It indicated that after sintering for 4, 6 and 8 times, zirconia ceramics could have a good shear strength binding to resin adhesives;with the increasing of sintering times, the shear bond strength could be increased.

Objective To investigate the factors that induce constipation in bedridden patients undergoing replantation of severed finger and find countermeasures. Methods A retrospective investigation was carried out in 92 patients undergoing replantation of severed finger, their constipation and factors influencing constipation were recorded. Results 61 patients suffered from constipation in total 92 cases,the rate being 66.30%. 76 patients reduced food intake, and 59 cases presented constipation (the rate being 77.63%). Factors influencing constipation included being unaccustomed to defecate in bed (the rate that present with constipation being 87.09%),reluctant to trouble others(75.47%), side effects of drugs(55.56%) and lack of dietary knowledge (71.87%), decreasing food intake was closely bound up with constipation. Conclusions Proper psychological counseling, strengthening of health propaganda, comfortable facility for defecation, improved family support and oral food intake can significantly reduce the proportion of constipation and increase comfort degree of patients.

Objective To explore the electrophysiological properties and the disparity of visual cortical neurons in developing rats. Methods Whole cell patch clamp recording and intracellular labeling of brain slices were performed on rats at postnatal 14 and 28 days. The electrophysiological data were analyzed according to the cellular input resistance and resting membrane potential. Results When the input impedance of visual cortical neurons(IR) was lower, increased peak value of postsynaptic currents(PSCs), prolonged rise and decay time were found. At postnatal 14th day(before eyes opened), the intermediate cells and mature cells were 59.2% and 14.9% respectively, but at postnatal 28th day(14 days after eyes opened), the mature cells and immature cells were 62.5% and 12.5% respectively. Conclusion During the period of postnatal development, the visual cortical neurons become mature gradually, but maturation is not completely correlated with age.

Objective To investigate the prevalence, clinical features, diagnosis, treatment and the influence on procreation of uterine malformation. Methods Totally 225 women with uterine malformation referred to our hospital from Mar 1990 to Jan 2005 were involved in this retrospective analysis.The constituent ratio, clinical feature, diagnosis, treatment and the influence on procreation were analyzed.Results (1) Among 225 cases of uterine malformation, 125 cases (55.6%) were septate uterus; 122(97.6%, 122/125 ) of these patients became pregnant, but always associated with a high risk of reproductive failure and obstetrical complications, such as abortion, abnormal fetal presentation, premature rupture of membrane. (2) Among 51 cases (22. 2%, 51/225 ) of didelphia, 50 cases (98%, 50/51 )became pregnant without any influence from this malformation. Five cases were combined with urinary system complication. (3) Among 26 cases (9.7%, 26/225 ) of rudimentary horn of uterus, 4 cases (15%, 4/26)became pregnant, and 1 case (4%, 1/26) presented with ipsilateral oviduct ectopic pregnancy; 2 cases (8%, 2/26) were combined with urinary deformities. (4) In 14 cases (6. 2%, 14/225) of bicornuate uterus, 1 case (7%, 1/14) presented with urinary tract abnormalities; gestations were more common, but due to the uterine structural abnormality, recurrent miscarriage and premature delivery were unavoidable.(5) Others: none came up with sterility in 4 cases (1. 8%, 4/225) of saddle shaped uterus. All the three cases ( 1.3% , 3/225) of ametria were with the chief complaint of primary amenorrhea. Two cases of unicornis uterus (0.9%, 2/225) were both complicated with sterility, while neither with urinary system deformities. Conclusions Among uterine malformations, septate uterine is the most common type. Septate uterus, didelphic uterus, bicornuate and rudimentary horn of uterus do not affect pregnancy, but can cause different complications. Unicornis uterus always causes sterility. Uterus malformations often come up with urinary system deformities.

Objective To investigate the effect of diuretics combined with the new class volume-removing drugs nesiritide and tolvaptan on refractory heart failure (RHF).Methods We collected 78 patients with RHF from cardiovascular ICU in our hos-pital,and patients were divided into combined volume-removing drugs treatment group (CVR group)and traditional diuretics com-bined with inotropic treatment group (control group).We observed the differences in the heart failure symptoms control rate and the average hospitalization days between the two groups.The difference in average urine volume and weight loss during hospitaliza-tion was observed.Results The heart failure symptoms were controlled and successful discharge in 89.7% of patients in CVR group,which was better than that in control group(71.8%).The corresponding rates of death or abandonment was decreased sig-nificantly in CVR group,and the average number of hospitalization days in CVR group was significantly shorter than that in control group(P <0.05).Meanwhile,the average daily urine volume and the weight loss decreased significantly in CVR group than those in control group(P <0.05).Conclusion The therapy strategy of combined volume-removing drugs can significantly improve the vol-ume removing and control rate of heart failure symptoms.

AIM To investigate the effects of Tongluo Xingnao Effervescent Tablets (Chuanxiong Rhizoma,Angelicae sinensis Radix and Scutellariae Radix) on the learning and memory function in SAMP8 mice,and improvements in cognitive function.METHODS Morris water maze was used to evaluate the change of cognitive function in SAMP8 mice after they were treated with Tongluo Xingnao Effervescent Tablets for 60 d,and the activity of superoxide dismutase (SOD),the concentration of protein carbonyls (PC),the ratio of NAD +/NADH in brain tissue were detected by ELISA,the expression of Nampt,SIRT1 and FOXO3 in hippocampus were measured with immunohistochemical methods.RESULTS Tongluo Xingnao Effervescent Tablets shortened escape latency and obviously increased percentage of time in target quadrant in hidden platform test and increased the times entering the target quadrant in spatial probe test in SAMP8 mice.It evidently enhanced the activity of SOD,the ratio of NAD +/NADH and distinctly decreased the protein carbonyls level.Moreover,Tongluo Xingnao Effervescent Tablets could markedly up-regulate the expression of Nampt and SIRT1,but evidently down-regulate FOXO3 protein expression.CONCLUSION The experimental data show that Tongluo Xingnao Effervescent Tablets can enhance the cognitive function of SAMP8 through regulating Nampt/SIRT1/FOXO3 signal pathway.

9α-hydroxy-4-androstene-3,17-dione (9-OH-AD) is an important intermediate in the steroidal drugs production. 3-ketosteroid-9α-hydroxylase (KSH), a two protein system of KshA and KshB, is a key-enzyme in the microbial steroid ring B-opening pathway. KSH catalyzes the transformation of 4-androstene-3,17-dione (AD) into 9-OH-AD specifically. In the present study, the putative KshA and KshB genes were cloned from Mycobacterium smegmatis mc(2)155 and Gordonia neofelifaecis NRRL B-59395 respectively, and were inserted into the expression vector pNIT, the co-expression plasmids of kshA-kshB were obtained and electroporated into Mycobacterium sp. NRRL B-3805 cells. The recombinants were used to transform steroids, the main product was characterized as 9α-hydroxy-4-androstene-3,17-dione (9-OH-AD), showing that kshA and kshB were expressed successfully. Different from the original strain Mycobacterium sp. NRRL B-3805 that accumulates 4-androstene-3,17-dione, the recombinants accumulates 9α-hydroxy-4-androstene-3,17-dione as the main product. This results indicates that the putative genes kshA, kshB encode active KshA and KshB, respectively. The process of biotransformation was investigated and the results show that phytosterol is the most suitable substrate for biotransformation, kshA and kshB from M. smegmatis mc(2)155 seemed to exhibit high activity, because the resultant recombinant of them catalyzed the biotransformation of phytosterol to 9-OH-AD in a percent conversion of 90%, which was much higher than that of G. neofelifaecis NRRL B-59395. This study on the manipulation of the ksh genes in Mycobacterium sp. NRRL B-3805 provides a new pathway for producing steroid medicines.
Androstenedione ; analogs & derivatives ; biosynthesis ; Bacterial Proteins ; genetics ; metabolism ; Biotransformation ; Ketosteroids ; Mixed Function Oxygenases ; genetics ; metabolism ; Mycobacterium ; metabolism ; Mycobacterium smegmatis ; enzymology ; Plasmids

ObjectiveTo evaluate the performance of computer-aided detection (CAD) system for detection of pulmonary nodules in 64-slice low-dose CT screening and to investigate whether CAD can improve the performance of radiologists in detecting pulmonary nodules.MethodsOne hundred low-dose screening CT examinations were randomly selected from the database containing 578 consecutive cases between Jun 2007 and Jun 2008.All the examinations were performed on a 64-MSCT scanner with the exposure of 120 kVp,30 or 40 mA,or automatic exposure control.Before the study started,the screening reports had been made with double reading by two radiologists.All the selected images were analyzed with the lung VCAR software from GE Healthcare with a nodule diameter threshold 3.0 mm.All discrepancies between the screening reports and the CAD results were reviewed and the true non-calcified nodules were determined in consensus by two experienced chest radiologists.Detected nodules were classified by density,size and location.The performance of the double reading and the CAD system were compared and analyzed statistically.McNemar-Bowker test was used for the statistical analysis.ResultsA total of 257 true noncalcified nodules were determined in all 100 low-dose screening CT examinations.The detection rate of CAD system was 91.1％ (234/257),with the missed rate of 8.9％ (23/257).Twenty three nodules were missed by CAD,in which 10 were solid with the diameter ranged from 2.4 to 6.0 mm,and 13 were nonsolid with the diameter ranged from 2.1 to 8.6 mm.Of the 23 nodules,17 were located in the outer zones of lungs and 6 in the inner zones.The double reading showed a detection rate of 59.1％ ( 152/257 )and a missed rate of 40.9％ ( 105/257),which was significantly lower than CAD.The diameter of all the 105 missed nodules by radiologists were ranged from 2.4 to 11.8 mm,in which 94 nodules were solid,10 were partly solid and 1 was nonsolid,with 69 located in outer zones of lungs and 36 in the inner zones. Conclusions The capability of the CAD system for detecting non-calcified pulmonary nodules is superior to double reading in low-dose screening CT examination,especially for the nodules located in the inner zone of the lung.When lung VCAR is used,nonsolid pulmonary nodules are more easily missed so that it should be paid more attentions by radiologists.

Objective To evaluate the correlation of ADC values on 3.0 T MR with the pathological grades in pT1b clear cell renal cell carcinoma(CCRCC).Methods Conventional MR images,ADC values and Fuhrman pathological grading of pT1b CCRCC were performed in 30 patients.Grade Ⅰ and Ⅱ were defined as low-grade group; grade Ⅲ and IV were defined as high-grade group.The differences of ADC values among four different pathologic grades were compared with a one-way analysis of variance. The comparison of ADC values of two different grade groups was performed with t test,and the ROC curve was performed to evaluate the diagnostic efficacy of ADC value. Correlation between pathological gradings and ADC values was assessed with Spearman rank correlation analysis. Results ( 1 ) The mean ADC value of grading Ⅰ ( 10 patients ), Ⅱ ( 8 patients ),Ⅲ ( 7 patients ),IV ( 5 patients ) was ( 0.94 ± 0.11 ) ×10-3 mm2/s,(0.82 ±0.13) × 10-3 mm2/s,(0.68 ±0.09) × 10-3 mm2/s,(0.59 ±0.03) × 10-3 mm2/s,respectively.Significant differences of ADC values among the four grades were present (F =16.422,P =0.000 ).( 2 ) The mean ADC value of the low-grade group was significantly higher than that of the high-grade group(t =5.738,P =0.000).Sensitivity and specificity of diagnosing the low-grade group was 88.9％ and 83.3％ respectively.There was a negative correlation between pathological grading and ADC value ( r =-0.807,P ＜ 0.05). Conclusions The ADC values of pT1b CCRCC have close correlation with pathological gradings.They can be used to predict the degree of tumor malignancy preoperatively and guide surgical planning.

Objective To investigate the changes of CA125 between primary cytoreductive surgery and interval debulking surgery for prediction the rate of optimal interval cytoreductive surgery and prediction the recurrence and the prognosis in patients with epithelial ovarian cancer.Methods A total of 39 cases with suboptimal primary cytoreductive surgery admitted from Jan.1996 to Jan.2009 were retrospectively analyzed.The median age of patients was 56 years( range:41 -68 years).Based on the changes in CA125level between primary cytoreductive surgery and interval debulking surgery,all cases were divided into four groups,group A (CA125 reduced to normal after primary cytoreductive surgery,n=6),group B (CA125reduced to normal after 1 - 2 cycles of chemotherapy,n =11 ),group C ( CA125 reduced to normal after 3 -4 cycles of chemotherapy,n =14),and group D ( CA125 did not reduced to normal after the chemotherapy,n =8 ), and all received platinum-based chemotherapy.The response to chemotherapy evaluated by pathological examination versus CA125 level,and recurrence and prognoses were also analyzed.Results ( 1 )The rate of optimal interval cytoreductive surgery in group A,B,C and D were 6/6,8/11,9/14 and 2/8respectively,in which there were statistically different between group A or B and group D (P ＜0.05).(2)The clinical benefit rates evaluated by the pathological examination in group A,B,C and D were 4/6,4/11,5/14 and 0,respectively and there were statistically different between group A and group D (P =0.030).( 3 ) There was significant difference in the recurrence rate between group A and group D (3/6 vs.8/8,P =0.024),while there were not significant differences between group B or C and group D ( all P ＞ 0.05 ).The rate of drug-resistant recurrence in group A,B,C and D were 1/6,3/11,5/14 and 7/8,respectively,in which there were significant differences between group A,B or C and group D ( all P ＜ 0.05 ). ( 4 ) The median progression-free survival (PFS) for patients in group A,B,C and D were 32,10,18 and 3 months,respectively,in which there were significant differences in the PFS between group A,B or C and group D (P =0.012,P =0.003,P =0.032 ).The median overall survival (OS) were 44,45,44 and 16 months,respectively.There were significant differences in the OS between group A,B or C and group D ( P =0.022,P =0.004,P =0.000 ).Conclusion The change of CA125 between primary cytoreductive surgery and interval debulking surgery may be predict the recurrence type and the prognosis in patients with epithelial ovarian cancer.