OBJECTIVEThis study aims to determine the effect of fluoride concentration on the corrosion behavior of cobalt-chromium alloy fabricated by two different technology processes in a simulated oral environment.

METHODSA total of 15 specimens were employed with selective laser melting (SLM) and another 15 for traditional casting (Cast) in cobalt-chromium alloy powders and blocks with the same material composition. The corrosion behavior of the specimens was studied by potentiodynamic polarization test under different oral environments with varying solubilities of fluorine (0, 0.05%, and 0.20% for each) in acid artificial saliva (pH = 5.0). The specimens were soaked in fluorine for 24 h, and the surface microstructure was observed under a field emission scanning electron microscope after immersing the specimens in the test solution at constant temperature.

RESULTSThe corrosion potential (Ecorr) value of the cobalt-chromium alloy cast decreased with increasing fluoride concentration in acidic artificial saliva. The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes changed significantly when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes exhibited a statistically significant difference. The Icorr value of the cobalt-chromium alloy cast was higher than that in the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, tRp alues of the cobalt-chromium alloy cast were lower htan those of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P< 0 .05).

CONCLUSIONFluoride ions adversely affected the corrosion resistance of the cobalt-chromium alloy fabricated by two different technology processes. The corrosion resistance of the cobalt-chromium alloy cast was worse than that of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20%.

Chromium Alloys ; Corrosion ; Fluorides ; Lasers ; Phosphates ; Saliva, Artificial ; Sodium Fluoride

Objective To evaluate the short-and long-term outcomes of laparoscopy-assisted gastrectomy (LAG) for gastric cancer.Methods After studying the patients' demographic data,extent of gastrectomy and lymphadenectomy,as well as differentiation and tumor TNM stage,85 patients who underwent LAG were individually matched to 85 patients who underwent open surgery (OG) between October 2004 and March 2008.The operative time,intraoperative blood loss,postoperative recovery,complications,pathological findings,and follow-up data were compared between the two groups.Results The mean operative time was significantly longer in the LAG group than in the OG group (277 ± 62) min vs.(211 ±46) min,t =7.882,P ＜0.05,whereas intraoperative blood loss was significantly lower (161 ±90) ml vs.(267 ± 141) ml,t =-5.854,P ＜0.05.In addition,there was a significant reduction in the time to first flatus and postoperative hospital stay (3.7 ± 1.3) days vs.(4.2 ± 1.1) days and (10 ± 3) days vs.(12 ± 6) days,respectively t =-2.318,-2.325,P ＜ 0.05.There was no significant difference between the LAG group and OG group with regard to the number of harvested lymph nodes and overall postoperative complications.The 5-year disease-free survival rates and overall survival rates were 76％,78％,respectively,in LAG group and 75％,73％,respectively in OG group (all P ＞ 0.05).Conclusions LAG is suitable and minimally invasive for treating gastric cancer.Compared to OG,the LAG will not increase the risk of recurrence and mortality after surgery.

OBJECTIVE:To virtually screen lignanoid compounds with inhibitory effect of histone deacetylase(HDAC)by vir-tual screening method. METHODS:Using“lignanoid”as keyword,requiring CNKI,VIP,PubMed and other database,lignanoid compounds were collected as ligand to establish ligand base, histone deacetylase receptor HDAC2 (PDB code:4LXZ) and HDAC8 (PDB code:1T69) were selected from PDB database,and then ligands and 3D active site of receptors were docked by SYBYL-X 2.0 software. The affinity of receptors to ligand was reflected by total score. RESULTS:345 lignanoid compounds, 4LXZ and 1T69 primary ligand were used to establish ligand base which included 347 ligands. Ligands No.275,271,110,200, 056,258,181,129,037,270,187 were demonstrated good affinity with receptors HDAC2 and HDAC8. Ligands and receptors residue were docked via hydrogen bond. CONCLUSIONS:Lignanoid compounds have inhibitory effect on HDAC;virtual screen-ing method is effective in natural product activity prediction,which can provide quick access to and theoretical guidance for new pharmacological studies of lignanoid compounds.

In this paper, GLUT4 vesicles are observed in real-time under TIRF microscopy and a new three-dimensional single particle tracking algorithm according to the unique features of TIRF is put forward. Firstly a fluorescence correction procedure was processed to solve the problem of fluorescence bleaching over time and mobile vesicles were segmented by an adaptive background subtraction method. Kalman filtering was then introduced to track the granules so as to reduce the searching range and to avoid the disturbance of background noise and false targets. In the experiments the algorithm was applied in analyzing the long-distance movement of GLUT4 vesicles. The experimental results indicate that the algorithm has achieved robust tracking of the vesicles in the imaging plane and has effectively calculated the position in the direction orthogonal to the imaging plane.
Glucose Transporter Type 4 ; metabolism ; Imaging, Three-Dimensional ; instrumentation ; methods ; Ion Transport ; Microscopy, Fluorescence ; methods

BACKGROUNDFrequent premature ventricular complexes from the right ventricular outflow tract (RVOT-PVCs) are associated with left ventricular dysfunction. This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.

METHODSThis study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects. Aortic systolic velocity-time integral (AoVTI) and myocardium strain in circumferential (CS), radial (RS) and longitudinal (LS) directions were evaluated by conventional echocardiography and speckle tracking imaging. All values of patients with RVOT-PVCs were recorded during sinus (PVC-S) and PVC beats (PVC-V).

RESULTSSignificant differences were demonstrated in global CS, RS and LS between the control subjects and the PVC-V (CS: (17.46 ± 2.48)% vs. (11.52 ± 3.28)%, RS: (48.26 ± 10.20)% vs. (20.92 ± 9.78)%, LS: (19.89 ± 2.62)% vs. (11.79 ± 3.66)%, P < 0.01), and in segmental RS and LS of nearly all the left ventricular segments. Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior, anteroseptal and septal segments (only seen in anteroseptal and septal segments at apex). Furthermore, V/S AoVTI (AoVTI during the PVC beat divided by AoVTI during the sinus beat, then multiplied by 100%) correlated with coupling interval (r = 0.67, P < 0.001) and global strain (CS: r = 0.48, P = 0.007; RS: r = 0.65, P < 0.001; LS: r = 0.65, P < 0.001).

CONCLUSIONSFrequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction. The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.

Adult ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Ventricular Function, Left ; physiology ; Ventricular Premature Complexes ; physiopathology

Objective To investigate the effects of atorvastatin on advanced glycation end products (AGE) induced monocyte chemoattractant protein-1(MCP-1) expression in human umbilical vein endothelial cells(HUVECs)and whether this effect could be linked to peroxisome proliferator-activated receptor-γ (PPAR-γ) and nuclear factor-κB(NF-κB).Methods Grouping: (1)Blank control group;(2)BSA group;(3)AGE group:cells were incubated with different concentrations of AGE(10-4,10-3, 10-2 and 10-1g/L)for 24 hours; (4)AGE+Atorvastatin group: cells were incubated with different concentrations of atorvastatin(0.1,1,10 μmol/L)for 1 hour,then incubated with AGE (10-1 g/L) for 24 hours; (5)PPAR-γ agonist(15 d-PGJ2)group: cells were incubated with 15 d-PGJ2(10 μmol/L)for 1 hour,then incubated with AGE (10-1g/L) for 24 hours;(6)PPAR-γ inhibitor(GW9662)group:cells were incubated with GW9662(5000 nmol/L)for 1 hour,then incubated with atorvastatin (1 μmol/L)and AGE (10-1g/L) for 24 hours. Collagenase was used to isolate the endothelial cell from human umbilical vein;RT-PCR was performed to examine the mRNA expression of MCP-1 and PPAR-γ;Western blot was performed to detect NF-κB p65 protein.Results (1) The expression of MCP-1 mRNA was increased in proportion with increasing concentrations of AGEs which could be blocked by atorvastatin in a dose-dependent manner. (2) AGE(10-1g/L)significantly downregulated the expression of PPAR-γ mRNA(0.22±0.08 vs. 0.69±0.09, P<0.01) while upregulated the expression of phospho-NF-κB p65 protein (0.78±0.06 vs. 0.31±0.01,P<0.01) and nonphospho-NF-κB p65 protein (1.61±0.16 vs. 0.59±0.14,P<0.01) comparaed with the control group which could be significantly attenuated by atorvastatin. (3) PPAR-γ agonist decreased the expression of phospho-NF-κB p65 protein (0.21±0.01 vs. 0.78±0.06, P<0.01),nonphospho-NF-κB p65 protein (0.67±0.14 vs. 1.61±0.16,P<0.01)and MCP-1 mRNA (0.17±0.02 vs. 0.93±0.12, P<0.01)compared with AGE(10-1g/L)group. (4) PPAR-γ inhibitor antagonized the effect of atorvastatin on the expression of phospho-NF-κB p65 protein, nonphospho-NF-κB p65 protein and MCP-1 mRNA stimulated by AGE in HUVECs(P<0.01).Conclusion The anti-inflammatory properties of atorvastatin in AGE stimulated HUVECs may partly be attributed to the effect on upregulation of PPAR-γ and downregulation of NF-κB signaling pathway.

Objective To explore and evaluate the effect of improved drinking method on the respiratory failure patients with non-invasive mechanical ventilation.Methods Totals of 80 cases with noninvasive mechanical ventilation in the Chinese PLA General Hospital between October 2010 and October 2011 were recruited and randomly divided into observation group( n =40 ) receiving the improved drinking during non-invasive mechanical ventilation and control group( n =40) receiving the traditional drinking,taking off the mask and drinking.Pulse oxygen saturation,respiratory rate,heart rate,mean blood pressure,thirst score,cough and dyspnea were observed and recorded before drinking,at the end of drinking,5 min,30 min after drinking.Results There was no significant difference in gender,age and APACHE Ⅱ score between two groups( P ＞ 0.05 ).The observation group always had higher oxygen saturation than that of control group (95.2±2.3 vs 94.4 ±2.3,94.8 ±2.5 vs 91.8 ±3.4,95.1 ±2.0 vs 92.4 ±3.2,96.0 ±1.9 vs 93.4 ±2.9,P ＜0.05 ),and the incidence of cough,dyspnea was significantly lower than that of the control group ( 10.0％ vs 45.0％,5.0％ vs 22.5％ ),and after drinking 30 minutes,thirst score increased significantly in control group than that of the observation group ( 1.30 ± 0.60 vs 1.97 ± 0.65 ),and the difference was statistically significant( P ＜ 0.05 ).Conclusions Improved drinking method can achieve satisfied oxygen saturation during non-invasive mechanical ventilation with less possibility of cough and dyspnea.

Objective::Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks. Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.Methods::A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element (FE) software of LS-DYNA. The interaction between the detonation product and the warhead shell was simulated using the fluid-structure interaction algorithm. A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics (SPH) particles after the natural fragments were successfully formed. A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion.Results::The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes. The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured. The initial velocities of natural fragments at the central part of the warhead shell were the largest, whereas those at both ends of the warhead shell were the smallest. The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through. Stress waves propagated in the ribs and enhanced the injury to soft tissues; additionally, ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues.Conclusion::The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets. Moreover, this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.

To investigate the effect of end-capped modification of mPEG-PLA with Boc-phenylalanine(BP) on pharmacokinetic characteristics of curcumin(CUR) loaded micelles, and then provide experimental evidence for prescription optimization. Healthy male SD rats were randomly divided into three groups and they were intravenously administered with a single injection of CUR-mPEG-PLA micelles, CUR-mPEG-PLA-BP micelles and reference formulations DMSO solution(n=6). The doses were 20 mg•kg⁻¹ in term of CUR. Blood samples were collected before and after administration, and the concentration of curcumin in blood plasma was determined by HPLC to draw time-concentration curve. Non-compartmental pharmacokinetic parameters were calculated by using DAS 2.0 software and statistical analysis was conducted between the different groups. The results indicated that the pharmacokinetic characteristics of CUR-mPEG-PLA micelles were similar to those of the free drug of CUR dissolved in DMSO, and the main pharmacokinetic parameters had no significant difference between the two groups. However, as compared with CUR-mPEG-PLA micelles, CUR-mPEG-PLA-BP micelles had a significantly increased area under the time-concentration curve(AUC), significantly prolonged half-life of elimination(tl/2) and mean residence time(MRT), and reduced total body clearance(Cl) (P<0.05). In conclusion, the amphipathic block copolymer of mPEG-PLA-BP could provide curcumin loaded micelles with preferable pharmacokinetic properties in vivo, and CUR-mPEG-PLA-BP micelles were worthy of further research and development.

OBJECTIVETo determine the karyotype of a patient with Prader-Willi-like syndrome features.

METHODSChromosomal high resolution banding was carried out to analyze the karyotype of the patient, and methylation-specific PCR was used to analyze the imprinting region of chromosome 15. Subtelomeric region was screened by multiplex ligation-dependent probe amplification (MLPA), and fluorescent in situ hybridization (FISH) and real-time quantitative PCR were further performed to identify the deleted region.

RESULTSNo abnormality was discovered by high resolution karyotype analysis and methylation-specific PCR studies. MLPA analysis showed that the patient had a deletion of 1p subtelomeric area, which was confirmed by FISH analysis. The deleted region was shown within a 4.2 Mb in the distal 1p by 3 BAC FISH probes of 1p36 combined with real-time PCR technique. Family pedigree investigation showed the chromosome abnormality was de novo. Therefore, partial monosomy 1p36 was likely responsible for the mental retardation of the patient.

CONCLUSIONMolecular cytogenetic techniques should be performed to those patients with Prader-Willi-like syndrome features, to determine their karyotypes.

Child ; Chromosome Deletion ; Chromosomes, Human, Pair 1 ; genetics ; Female ; Humans ; Karyotyping ; Prader-Willi Syndrome ; genetics