?Objective: To study the preparation method of nanometer powder of zirconia, which was used to toughen dental alumina ceramics. Methods: The inorganic precursors at the concentrations of 0.0155 , 0.03, 0.05, 0.1 and 0.28 mol/L were used to prepare zirconia powder via precipitation method. Ammonia water was added into the said solutions to control the pH value at 7.0, 8.5 and 9. The dried precipitation product was then calcined. The prepared zirconia powder were studied by using X ray diffraction (XRD) and scanning electron microscope (SEM). Results: The zirconia powder prepared under the condition of 0.03 0.05 mol/L concentration of inorganic precursors, pH = 8.5, and calcined at 700 ℃ for 2 h was even in size,well dispersed and well micronized. The diameter of the final powder was about 100 nm. Conclusion: With proper preparation condition, weakly agglomerated powder of zirconia in nanometer size can be obtained.

Objective To analyze the thin-section CT features of fissure-attached nodules in asymptomatic patients.Methods The baseline and follow-up CT images of 120 asymptomatic patients with fissure-attached nodules were retrospectively analyzed.The thin-section CT findings include size,shape,density,interface,and the relationship with pulmonary fissure.Results There were 1 67 fissure-attached nodules of the 120 patients.The mean length of nodules was 5.46 mm±2.276 mm (2 - 1 5 mm).104(104/1 67,61.1%)nodules were less than 5 mm in length.1 63 (1 63/1 67,97.6%)nodules were typical and 4 (4/1 67,2.4%)nodules were atypical.All these nodules manifested as homogenous,solid,smooth interface,and widely adjacent to the fissure on CT ima-ges.Among those nodules,1 64(1 64/1 67,98.2%)nodules were triangular(88/1 67,52.7%)or oval(76/1 67,45.5%).126(126/1 67, 75.4%)nodules were abutting the major fissure.The angle between nodule and fissure was obtuse in 1 64(1 64/1 67,98.2%)fissure-attached nodules.During follow-up,4(4/1 67,2.4%)nodules increased in size and the corresponding volume doubling time (VDT) range was 863-4 228 days.However,no obvious malignant signs were found.Conclusion The thin-section CT images of fissure-attached nodules in asymptomatic patients showed the benign characteristics,most of which less than 5 mm and demonstrated trian-gle or oval,smooth interface and homogenous solid density.

Lignin degradation products are toxic to microorganisms, which is one of the bottlenecks for fuel ethanol production. We studied the effects of phenolic ketones (4-hydroxyacetophenone, 4-hydroxy-3-methoxy-acetophenone and 4-hydroxy-3,5-dimethoxy-acetophenone) derived from lignin degradation on ethanol fermentation of xylose and cellular lipid composition of Pichia stipitis NLP31. Ethanol and the cellular fatty acid of yeast were analyzed by high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS). Results indicate that phenolic ketones negatively affected ethanol fermentation of yeast and the lower molecular weight phenolic ketone compound was more toxic. When the concentration of 4-hydroxyacetophenone was 1.5 g/L, at fermentation of 24 h, the xylose utilization ratio, ethanol yield and ethanol concentration decreased by 42.47%, 5.30% and 9.76 g/L, respectively, compared to the control. When phenolic ketones were in the medium, the ratio of unsaturated fatty acids to saturated fatty acids (UFA/SFA) of yeast cells was improved. When 1.5 g/L of three aforementioned phenolic ketones was added to the fermentation medium, the UFA/SFA ratio of yeast cells increased to 3.03, 3.06 and 3.61, respectively, compared to 2.58 of the control, which increased cell membrane fluidity and instability. Therefore, phenolic ketones can reduce the yeast growth, increase the UFA/SFA ratio of yeast and lower ethanol productivity. Effectively reduce or remove the content of lignin degradation products is the key to improve lignocellulose biorefinery.
Acetophenones ; chemistry ; Ethanol ; chemistry ; Fermentation ; Industrial Microbiology ; Ketones ; chemistry ; Lignin ; chemistry ; Lipids ; chemistry ; Phenols ; chemistry ; Pichia ; chemistry ; Xylose ; chemistry

OBJECTIVEThe purpose of this study was to explore the preparation method of nanometer powders of dental alumina ceramics.

METHODSThe effects of concentration of inorganic precursors, pH value, calcination temperature and ageing time on the synthesizing process, phase composition and microstructure of the materials were studied. Aluminium nitrate with concentrations of 0.03 mol/L, 0.05 mol/L, 0.1 mol/L and 0.2 mol/L were used as inorganic precursors to prepare alumina powders via sol-gel method. Ammonia water was added into the solutions to adjust the pH values to 5, 9 and 11. The dried gel was then calcined under different temperatures, from 950 degrees C to 1200 degrees C. The prepared alumina powders were studied by using X-ray diffraction (XRD), and scanning electron microscope (SEM).

RESULTSThe alumina powder which was prepared with 0.1 mol/L aluminium nitrate, pH 9, and calcined at 1200 degrees C for 10 min showed good physical characteristics. The diameter of final powder was about 70 nm.

CONCLUSIONWith the proper preparation condition, weakly agglomerated powders of alumina in nanometer particle size could be obtained.

Aluminum Oxide ; chemistry ; Biocompatible Materials ; chemical synthesis ; Ceramics ; chemical synthesis ; Dental Materials ; chemical synthesis ; Dental Porcelain ; chemistry ; Gels ; Hydrogen-Ion Concentration ; Nanotechnology ; Particle Size ; Powders

Objective To evaluate the role of calcium/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) in the neuronal damage induced by lidocaine.Methods SH-SY5Y cells were seeded in 96-well plates (100 μl/hole) with a density of 5 × 105/ml and randomly divided into 4 groups (n =63 each):normal culture group (C group),CaMK Ⅱ inhibitor KN93 (K group),lidocaine group (L group) and KN93 + lidocaine group (KL group).KN93 (final concentration 1 μmol/L) was added to the culture medium and the cells were then cultured for 24 h in group K.Lidocaine (final concentration 10 mmol/L) was added to the culture medium and the cells were then cultured for 24 h in group L.KN93 (final concentration 1 μmol/L) and lidocaine (final concentration 10 mmol/L) were added to the culture medium and the cells were then cultured for 24 h in group KL.The cell morphology was examined with microscope after 24 h of incubation.The viability of cells was measured by MTT assay before incubation and at 1,6,12 and 24 h of incubation.The apoptosis in the cells was assessed by flow cytometry.The apoptotic rate was calculated.Results Compared with C and K groups,the cell viability was significantly decreased and the apoptotic rate was increased in L and KL groups (P ＜ 0.05).The cell viability was significantly higher and the apoptotic rate was lower in group KL than in group L (P ＜ 0.05).There was no significant difference in the cell viability and apoptotic rate between C group and K group (P ＞ 0.05).The pathological changes were obviousin group L and significantly reduced in group KL.Conclusion CaMK Ⅱ is involved in the neuronal damage induced by lidocaine.

Objective To observe the expression of calcium/calmodulin dependent protein kinase Ⅱ (CaMK Ⅱ) in the spinal cord of the rats followed lidocaine hydrochloride intrathecal injection.Methods 48 male SD rats weight(230 ± 20) g,after intrathecal indwelling catheter,were randomly divided into four groups (n =12,8 rats for behavioral detection and 4 rats for western blotting):normal group (C group),sham group (S group),DMSO group (D group),10％ lidocaine group (L group).Mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were detected before and after 2 h,4 h,8 h,12 h,1 d,2 d,3 d,4 d and 5 d with drug treatment.Intumescentia lumbalis of the spinal cord were collected to measure the expression of CaMK Ⅱ with western blotting after drug treatment for 12 h.Results The based MWT of the rats in C,S and D group were (11.2 ± 3.1) g,(11.8 ± 2.2) g and (11.4 ± 2.4) g respectively.There were no differences among the every time points (n=8,P＞0.05).The MWT of the rats in L group significantly increased at 2 h,4 h,8 h,12 h,1 d,2 d,3 d and 4 d after treatment with lidocaine hydrochloride,and the data were (22.0 ± 6.6) g,(22.2 ± 5.3) g,(20.5 ±5.8)g,(18.5 ±4.3)g,(16.7 ±3.2)g,(15.2 ±3.1)g,(15.5 ±3.5)g,(13.7 ±2.4)g respectively (n=8,P＜0.01).TWL had no difference among the rats in C,S,and D group(n=8,P＞0.05).The TWL of the rats in L group significantly increased at 2 h,4 h,8 h,12 h,1 d,2 d and 3 d after treatment with lidocaine hydrochloride(n =8,P＜ 0.01).The expression of CaMK Ⅱ of the rats in C group,S group,D group and L group were 0.17 ± 0.03,0.16 ± 0.03,0.19 ± 0.05,0.42 ± 0.11,and significantly upregulated in L goup (n =4,P ＜ 0.01).Conclusion Lidocaine hydrochloride intrathecal injection can increase the expression of the CaMK Ⅱ in the spinal cord of the rats.Those indicate that CaMK Ⅱ may be involved with the nerve damage induced by lidocaine hydrochloride.

Objective: To study the properties and behavior of dynamics in the tactical reserve models of medicine supplies. Methods: A tactical reserve model of medicine supplies was established with methods of systematic dynamics, and the behaviors of the system was simulated by computer program when parameters changed. Results:The quantity of initial reserve did not obviously effect the average inventory and amount of goods in short. However, objective reserve, rate of supply and rate of deliver evidently affected average inventory and amount of goods in short. Conclusion: The system efficiency is not influenced if the rate of supply is guaranteed.

Objective To establish the differential templates of juvenile and children in Shandong with normal occlusion, according to the group of skeletal age. Methods 212 juvenile and children at the age of 8-16 years (107 males and 105 females) with normal occlusion in Shandong natives were took cephalomatric radiographs, and divided into different groups by cervical vertebrae skeletal age. Then these cephalomatric radiographs were scanned on the computer and 14 skeletal landmarks were vectorizated. An analytical method of Ricketts and McNamara with WinCept 7.0 was used to make statistics and variance analysis among gender and every group of cervical vertebrae skeletal age,and then established the templates. Results The juvenile and children in Shandong natives with normal occlusion had different templates. Conclusion By overlapping the same skeletal age of templates by SN plane, we can see that male face outline is greater than female and male mandibular plane angle is smaller than female. By overlapping the same gender of templates, there is a developmental trend of mandibular bone to be forward and downward, and to revolve anticlockwise with age.

Objective To investigate the role of T-type calcium channel in lidocaine-induced neuronal cytotoxicity . Methods SH-SYSY cell line was a gift from cell biology laboratory of our medical university. The cells were cultured in DMEM liquid culture medium at 37℃ in incubator filled with 5% CO2 , and randomly divided into 4 groups ( n = 66 each) : control group (group C)and M, L and ML groups were exposed to 5 μmol/L mibefradil (a T-type calcium channel blocker), 10 mmol/L lidocaine and 5 μmoL/L mibefradil + 10 mmol/L lidocaine for 24 h. Cell morphology was examined by electronic microscopy at 24 h of drug exposure. Cell viability (by MTT) and neuronal apoptosis (by flow cytometry) were detected immediately before and at 1, 6, 12 and 24 h of exposure to mibefradil or/and lidocaine.Results In C and M groups, the cells demonstrated dendritic protrusions, enlarged nerve processes and dense lattice. After being exposed to lidocaine for 24 h, the dendritic protrusions disappeared,the cells decreased in size, shrinked and became round; the cell viability was significantly decreased while the neuronal apoptosis increased. The lidocaine-induced changes were significantly attenuated by co-incubation with mibefradil. ConclusionT-type calcium channel is involved in lidocaine-induced neuronal cytotoxicity.

ObjectiveTo establish a rat model of nerve damage induced by intrathecal(IT) lidocaine.MethodsFifty-five adult male SD rats weighing 200-220 g were randomly divided into 5 groups (n =11 each):group normal control (group C); group dimethyl sulfoxide (DMSO)-the solvent(group D) and groups IT 5％,10％,15％ lidocaine (groups L5.10.15 ).IT catheter was successfully implanted without complication in groups D,L5,L1o,L15.DMSO,5％,10％ and 15％ lidocaine 20 μl were injected IT in groups D,L5,L10,L15 respectively.Motor dysfunction of hindlimb was assessed and scored (0 =normal,2 =complete block) and paw withdrawal threshold to mechanical stimulation (von Frey filaments) (MWT) and paw withdrawal latency to thermal nociceptive stimulus (TWL) were measured before (baseline) and at 1,2,3,4,5,7 d after IT administration in 8 animals in each group.Three animals in each group were sacrificed at 1 d after IT administration.The lumbar segment (L4-5) was removed for microscopic examination.ResultsThere was no significant difference in motor dysfunction score,MWT and TWL among groups C,D and L5.MWT was significantly increased and TWL prolonged at 1 and 2 d after IT administration in group L10,while in group L15 motor dysfunction score was significantly increased at 1,2 d after IT administration and MWT was significantly increased and TWL prolonged at 1,2,3 d after IT administration.There was significant histologic damage to spinal cord in groups L10 and L15.Conclusion Nerve damage can be induced by IT 10％ lidocaine.