OBJECTIVETo evaluate the effects of thermal and mechanical cycling on the metal-ceramic bond strength of machine-milled Ti2448 alloy and commercial pure titanium (cp Ti).

METHODSCeramic-cp Ti (n = 30) specimens and ceramic-Ti2448 combinations (n = 30) were prepared in accordance with ISO 9693. The specimens from each metal-ceramic combination were randomly divided into three subgroups. In group A or the control group, the specimens were only stored in distilled water for 24 h at 37 °C; in groups B and C, the specimens were subjected to 3,000 cycles of thermal cycling between 5 and 55 °C for a dwell time of 60 s and to mechanical cycling of 20,000 or 40,000 cycles with 50 N load and 4 Hz in distilled water at 37 °C. A crack initiation test was performed using a universal testing machine in accordance with ISO 9693. Failure types at the metal-ceramic interface and the morphological and elemental composition of this interface were analyzed using a scanning electron microscope and an energy dispersive spectrometer. Statistical analysis was performed via two-way ANOVA and Tukey's adjustment test (α = 0.05).

RESULTSThe bond strength of the ceramic-Ti2448 combination was significantly higher than that of the ceramic-cp Ti combination regardless of fatigue conditions (44.86 MPa ± 1.75 MPa and 29.21 MPa ± 2.20 MPa for Ti2448 and cp Ti, respectively; P < 0.01). The mean bond strengths of ceramic-cp Ti and ceramic-Ti2448 combinations in group C were significantly lower than that of group A (P < 0.01). Although ceramic-cp Ti combination failed adhesively at the metal-ceramic interface without the ceramic on the substrate surface, Ti2448 frameworks exhibited cohesive failure; as a result, large amounts of residual porcelain were retained on the specimens.

CONCLUSIONThe metal-ceramic bond strength of cp Ti and Ti2448 is decreased by thermal and mechanical cycling.

Cardiomyopathies ; Heart Ventricles ; Humans

Objective To realize fully automatic X-ray exposure controlling,simplify operating processes,and improve the quality of images.Methods We designed 5 or 7 X-ray detectors with silicon batteries,improved film-holding board of the main engine of the X-ray machine,then assembled them by mechanical gearing,and thus made multi-measured-limit,automatically-changed X-ray detectors.Results When choosing film boxes according to the radiographed positions,the detectors will change automatically into measured-limits coinciding with the interested positions.The average density was around 1Ⅴ in 9 randomly selected photographs.High quality was achieved in up to 98% of 10 000 radiographed images for clinic radiography.Conclusion The key of X-ray automatic exposure controlling technology is X-ray detecting technology,by which the quality of image can be improved.

Objective To study the state of T-cell and T-helper cell subpopulation in children with recurrent tonsillitis(RT) in remission period and make clear its role on pathogenesis in children with RT.Methods The expression of membrane molecule on T-cell subsets was analyzed in 27 RT children and 21 control health children by using immunofluorescence and flowcytometry,the levels of interferon-?(IFN-?) and interleukin-4(IL-4) in culture supernatant of peripheral blood mononuclear cells(PBMC) were detected by enzyme linked immunoadsorbent assay(ELISA).Results The CD4~+ and CD3~+ cell were significantly lower in RT children than those of the controls(P0.05),a ratio of CD4~+/CD8~+ was disproportion(P0.05),the ratio of Th1/Th2 was disproportion(P

No abstract available.
Hepacivirus* ; Hepatitis C* ; Hepatitis*

In the study, the inhibitory effect of epigallocatechin gallate (EGCG) on Calcium oxalate nephrolithiasis and its possible mechanism were investigated. The rat Calcium oxalate nephrolithiasis model was induced through the combined oral administration of ethylene glycol and ammonium chloride, which was intervened with EGCG. Rat blood samples were collected to detect blood creatinine (Cr), blood urea nitrogen (BUN) and blood calcium. Rat urine samples were collected to observe and compare 24-hour urine volume, oxalic acid (Ox) and calcium in urine. Renal samples were collected to prepare tissue slices and observe the pathological changes in Calcium oxalate nephrolithiasis. The expression of osteopontin (OPN) in renal tissues was evaluated by Real-time PCR and Western blot. According to the results, compared with normal rats, rats in the nephrolithiasis model showed significant increases in Cr, BUN, urine Calcium, urine Ox and renal OPN expression (P < 0.05), but obvious decrease in 24-hour urine volume (P < 0.05); Compared with rats with nephrolithiasis, those processed with EGCG revealed remarkable declines in Cr, BUN, urine Calcium and urine Ox (P < 0.05), with significant rise in 24-hour urine volume (P < 0.05) in a concentration-dependent manner. Additionally, compared with the control group, nephrolithiasis rats showed significant pathological changes in Calcium oxalate calculus. After ECCG treatment, the renal pathological changes and OPN expression attenuated significantly in a concentration-dependent manner. The results showed that EGCG inhibits the formation of calcium oxalate nephrolithiasis in rats and shows a notable protective effect on renal functions.
Animals ; Blood Urea Nitrogen ; Calcium ; blood ; Calcium Oxalate ; metabolism ; Catechin ; administration & dosage ; analogs & derivatives ; Creatinine ; blood ; Disease Models, Animal ; Humans ; Kidney ; drug effects ; metabolism ; Male ; Nephrolithiasis ; blood ; drug therapy ; genetics ; Osteopontin ; genetics ; metabolism ; Rats ; Rats, Wistar

Finite element analysis can be used to study the change of the structure and the interior field intensity of human and animal body organs and tissues with simulation experiment. We in our research used finite element analysis software to analyze and solve the spinal cord surface potential problems, and investigated the transmission features of signals generated by interneurons in spinal nerves which were related with body motion control and sensory processing. A three dimensional model of electrical source in rat spinal cord was built, and the influence on potential distribution on spinal cord surface caused by position changes of electrical source in transverse direction and dorsoventral direction were analyzed and calculated. We obtained the potential distribution curves of spinal cord surface and found that the potential distribution on spinal cord surface showed monotone. In addition, potentials of some registration points were smaller than that of registration points around.
Action Potentials ; Animals ; Computer Simulation ; Finite Element Analysis ; Humans ; Interneurons ; physiology ; Models, Anatomic ; Rats ; Spinal Cord ; physiology

Objective To investigate the effects and related mechanism of iNO on erythrocyte deformability in septic acute lung injury(ALI).Methods Thirty anesthetized and mechanically ventilated young piglets(3-4weeks old)were allocated to 4 groups:(1)normal(group C,n=6):intraperitoneal injection of normal saline(NS).(2)normal+iNO(group CNO,n=4):NS followed by mechanical ventilation for 4 h,and then treated with iNO at 10 parts per million in volume(ppm).(3)model(group M,n=10):i.p.Escherichia coli at 5 × 109 cfu/ml,5 ml,and(4)NO(group MNO,n=10):i.p.Eschefichia coli at 5×109 cfu/ml lollowed by iNO-at 10 parts per million after ALI.Blood viscosity,malondialdehyde(MDA)in erythrocyte,Ca2+-Mg2+-ATPase and Na+-K+-ATPase of erythrocyte membrane were measured at basdine,establishment of ALI,12 and 24 h during the treatment.Results For normal age-matched piglets,there was little change of whole blood viscosity at high shear rate(110 s-1),which is a measure of erythrocyte deformability,so was the level of MDA in erythroeyte and the activity of erythroeyte membrane Ca2+-Mg2+-ATPase,Na+-K+-ATPase when iNO was provided for 12 or 24 h.At the time ALI was established,whole blood viscosity at high shear rate and MDA levels in erythroeyte increased significantly compared to the baseline level(P＜0.05),while the activity of erythrocyte membrane Ca2+-Mg2+-ATPase and Na+-K+-ATPase decreased significantly(P＜0.01,vsbaseline).Exposure of iNO for 12 h resulted in decreased whole blood viscosity at high shear rate and MDA levels in erythroeyte(P＜0.05,vs group C),and higher activity of erythrocyte membrane Ca2+-Mg2+-AT-Pase and Na+-K+-ATPase.When iNO was administered for 24 h,there was little difference of whole blood viscosity,activity of erythrocyte membrane Ca2+-Mg2+-ATPase,Na+-K+-ATPase and MDA levels in erythroeyte between the C and NO groups.Conclusion In the piglets with septic ALI,there was deterioration of erythrocyte deformability.Inhaled NO for 12 h may alter the deterioration,however,this effect is transient.

Objective To study disfunction of activated T cell from peripheral blood and explore its role on pathogenesis in patients with refractory mycoplasma pneumoniae pneumonia (MPP).Methods T cell subsets and expression of membrane molecule on activated T cell in peripheral blood were measured in 26 refractory MPP patients by using immunofluorescence and flowcytometry,and compared with those of 18 control healthy children.Results The percentage of CD4~+ cell from peripheral blood in refractory MPP children was significantly lower than that in control group(P0.05).Conclusions There are disfunctions of T cell in refractory MPP patients in acute period,and the abnormal T cell activated disfunction may play an important role on pathogenesis.

Objective To study the safety and efficacy of retroperitoneal laparoscopic resection of adrenal neurilemmoma.Methods The data of 7 cases with adrenal neurilemmoma undergoing retroperitoneal laparoscopic resection were analyzed.2 cases were diagnosed by ultrasound scan,3 cases had blood pressure elevation,and 2 cases had pain in waist and abdomen.All cases underwent ultrasound and CT scan.The neurilemmoma was located in left adrenal area in 2 cases and located in right adrenal area in 5 cases.Results All the 7 cases were successfully operated.No conversion or severe blood loss happened.The average tumor size was 5.0 cm,ranging from 3.0 to 7.0 cm.The average operation time was 75 min,ranging from 45 to 120 min.The estimated blood loss was 50 ml,ranging from 20 to 100 ml.The patients were discharged 7-8 day after the operation.During the 2-12 months of follow-up,no recurrence or metastasis was found.Conclusion Retroperitoneal laparoscopic resection offers an effective and better treatment for adrenal neurilemmoma,with the advantages of less blood loss,less trauma,and faster recovery.