Iatrogenic atrial septal defect after HotBalloon ablation of atrial fibrillation.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of atrial fibrillation (AF). Balloon ablation requires a larger sheath, which raises the concern for a persistent iatrogenic atrial septal defect (iASD). The present study aimed to investigate the incidence, clinical features, and the predictive factors of transthoracic echocardiography (TTE)-detectable iASD after HBPVI. All patients who underwent HBPVI of AF with pre- and post-ablation TTE were retrospectively analyzed. A 17-French steerable deflectable guiding sheath was inserted into the left atrium (LA) after a transseptal puncture, and an 8-French sheath was inserted via a single transseptal hole. In a total of 190 patients, 98 (52%) paroxysmal AF (PAF) and 92 (48%) non-PAF, the iASD was detected in 18 (9.4%) with a mean follow-up period of 12.7 ± 2.5 months after HBPVI. All patients had no clinical symptoms related to iASD. No embolic or heart failure events occurred. In the multivariate analysis, LA volume index and LA procedure time were identified as significant independent predictors of iASD. After HBPVI, TTE-detectable iASD was found in 9.4% of study patients. Larger LA size and longer LA procedure time were predictive factors for the persistence of iASD. All patients with iASD had no clinical symptoms 12 months after HBPVI; however, long-term follow-up may be necessary.

The precordial R' wave: A novel discriminator between cardiac sarcoidosis and arrhythmogenic right ventricular cardiomyopathy in patients presenting with ventricular tachycardia.

BACKGROUND: Cardiac sarcoidosis (CS) with right ventricular (RV) involvement can mimic arrhythmogenic right ventricular cardiomyopathy (ARVC). Histopathological differences may result in disease-specific RV activation patterns detectable on the 12-lead electrocardiogram. Dominant subepicardial scar in ARVC leads to delayed activation of areas with reduced voltages, translating into terminal activation delay and occasionally (epsilon) waves with a small amplitude. Conversely, patchy transmural RV scar in CS may lead to conduction block and therefore late activated areas with preserved voltages reflected as preserved R' waves. OBJECTIVE: The purpose of this study was to evaluate the distinct terminal activation patterns in precordial leads V1 through V3 as a discriminator between CS and ARVC. METHODS: Thirteen patients with CS affecting the RV and 23 patients with gene-positive ARVC referred for ventricular tachycardia ablation were retrospectively included in a multicenter approach. A non-ventricular-paced 12-lead surface electrocardiogram was analyzed for the presence and the surface area of the R' wave (any positive deflection from baseline after an S wave) in leads V1 through V3. RESULTS: An R' wave in leads V1 through V3 was present in all patients with CS compared to 11 (48%) patients with ARVC (P = .002). An algorithm including a PR interval of ≥220 ms, the presence of an R' wave, and the surface area of the maximum R' wave in leads V1 through V3 of ≥1.65 mm2 had 85% sensitivity and 96% specificity for diagnosing CS, validated in a second cohort (18 CS and 40 ARVC) with 83% sensitivity and 88% specificity. CONCLUSION: An easily applicable algorithm including PR prolongation and the surface area of the maximum R' wave in leads V1 through V3 of ≥1.65 mm2 distinguishes CS from ARVC. This QRS terminal activation in precordial leads V1 through V3 may reflect disease-specific scar patterns.

Pulmonary vein stenosis after HotBalloon pulmonary vein isolation of paroxysmal atrial fibrillation.

HotBalloon-based pulmonary vein isolation (HBPVI) has yielded encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF). However, pulmonary vein (PV) stenosis remains a concern. The influence of longer application duration on PV stenosis has not yet been systematically evaluated. All patients who underwent first HBPVI of PAF with pre- and post-ablation computed tomography (CT) were included. We used single-shot technique with application duration of 180 s in the RSPV, 180-240 s in the LSPV, and 120 s in the lower PV procedures. PV stenosis was analyzed using CT and categorized as moderate (50-70%), and severe (> 70%) reduction in PV diameter. We analyzed imaging of the PV anatomy before ablation and during follow-up in 84 patients. Among them, 7 (8.3%) showed moderate stenosis, and 3 (3.6%) had severe stenosis including one total occlusion patient. All severe stenosis and total occlusion occurred in RSPV and LSPV procedures with longer application duration. No severe stenosis nor total PV occlusion occurred in inferior PV procedures with shorter application duration. The incidence of PV stenosis ≥ 50% or total PV occlusion was significantly lower in inferior PV than RSPV and LSPV procedures (0.6%, 6.0%, 8.0%, p = 0.01, respectively). All cases of PV stenosis including total PV occlusion patients were asymptomatic. No intervention for PV stenosis was performed. The risk of PV stenosis in HBPVI was rare in lower PV procedure with shorter application duration. An application duration setting of 120 s in lower PV procedure might be effective to prevent PV stenosis.

Convergent Validity of Three Pressure Injury Risk Assessment Scales: Comparing the PPRA-Home (Pressure Injury Primary Risk Assessment Scale for Home Care) to Two Traditional Scales.

PURPOSE: The Pressure Injury Primary Risk Assessment Scale for Home Care (PPRA-Home) was developed to predict pressure injury risk in geriatric individuals requiring long-term care in home settings. This study aimed to compare the convergent validity of the PPRA-Home to that of the two other standardized pressure injury prevention scales: the Braden and Ohura-Hotta (OH) scales. METHODS: A multicenter, cross-sectional study was conducted with 34 home-based geriatric support service providers located in five Japanese districts. The study included 69 participants (30 had a pressure injury and 39 did not) who were at classified at care levels of 1 through 5 under Japan's long-term care insurance system. Care managers served as assessors for the PPRA-Home, while physicians or certified expert nurses served as assessors for the Braden and OH scales. Convergent validity was investigated by examining correlation coefficients between total scores on the PPRA-Home and the other two scales. Receiver operating curve analysis was used to quantify each scale's accuracy for the two groups: those with and without a pressure injury. RESULTS: The PPRA-Home was found to be negatively correlated with the Braden scale (r=-0.79, p<0.05), and positively correlated with the OH scale (r=0.58, p<0.05). The area under the curve (AUC) for the PPRA-Home, Braden scale, and OH scale were 0.737, 0.814, and 0.794, respectively. A PPRA-Home cutoff score of 4 had a sensitivity of 63.3% and specificity of 81.6%. CONCLUSION: The AUC for the PPRA-Home as scored by care managers was similar to those of the Braden and OH scales as scored by physicians or expert nurses. More research on the PPRA-Home's content and predictive validity is required.

Inter-Rater Reliability of a Pressure Injury Risk Assessment Scale for Home Care: A Multicenter Cross-Sectional Study.

PURPOSE: The aim of the current study was to assess the inter-rater reliability and agreement of the Pressure Injury Primary Risk Assessment Scale for Home Care (PPRA-Home), a risk assessment scale recently developed for Japan-specific social welfare professionals called care managers, to predict pressure injury risk in geriatric individuals who require long-term home care needs. METHODS: A multicenter cross-sectional study was conducted at 30 home-based geriatric support services facilities located at four local districts in Japan. Eligible participants were individuals who needed partial or full assistance for daily living under Japan's long-term care insurance system (care levels 1-5). The degree of agreement and kappa coefficient were calculated for each item and the total score, after which inter-rater reliability was determined. The effect of the participant's care level on reliability was also evaluated as secondary analysis. RESULTS: A total of 96 participants were assessed by 83 care managers (two assessors scored each participant). The degree of agreement and calculated kappa coefficient of the PPRA-Home total score were 59% and 0.72, respectively, with the inter-rater reliability for the total score determined to be "Substantial". Our subgroup analysis showed that the inter-rater reliability differed according to the participant's care level. Accordingly, the kappa coefficient for the total score was lower in subgroup "care level 1-3" than in subgroup "care level 4-5" (0.51 and 0.76, respectively). CONCLUSION: Our result showed that the PPRA-Home has substantial inter-rater reliability for evaluation of risks of pressure injury development at home care. However, some research focusing on intra-later reliability and validity of the PPRA-Home with adequate sample sizes are required to provide categorical conclusions on whether it can be used for the risk assessment scale in actual clinical settings.

Acute efficacy and clinical outcomes using HotBalloon for pulmonary vein isolation in patients with a left common pulmonary vein.

INTRODUCTION: HotBalloon material is compliant and the balloon size can be enlarged by increasing the intraballoon injection volume. HotBalloon-based pulmonary vein isolation (PVI) has demonstrated encouraging clinical results in the treatment of paroxysmal atrial fibrillation (PAF), however, the acute efficacy and clinical outcomes of the HotBalloon-based PVI have never been fully investigated in patients with a left common pulmonary vein (LCPV). METHODS AND RESULTS: One hundred fifty-three PAF patients underwent HotBalloon-based PVI. Three-dimensional computed tomography was performed in all patients before the ablation. An LCPV was observed in 40 (26%) patients. For HotBalloon ablation of an LCPV, in patients with an LCPV of superoinferior diameter <34 mm, the left common ostium was preferably isolated if sufficient occlusion could be achieved. In patients with an LCPV diameter ≥34 mm, left superior and inferior branches of the LCPV were targeted individually. The number of HotBalloon applications in patients with LCPV was significantly smaller than without LCPV (7.3 ± 2.0 vs 8.1 ± 2.1; P = .04). In patients with LCPV diameter <34 mm, 75% of LCPVs successfully achieved full balloon occlusion (50% were isolated by application at the LCPV ostium alone, 25% by application at the LCPV ostium followed by either superior or inferior LCPV branch ablation) and 25% were isolated individually. One year after a single session, the arrhythmia-free rates were similar between patients with and without LCPV (77% vs 74%, log rank, P = .86). CONCLUSIONS: HotBalloon-based PVI delivers long-term favorable success rates with fewer HotBalloon applications in paroxysmal AF patients with an LCPV.

Insights into guidewire related complication during HotBalloon ablation in patients with atrial fibrillation: What should we know?

A 78-year-old woman with drug-resistant persistent atrial fibrillation was referred for catheter ablation by HotBalloon. All pulmonary veins were successfully ablated by the HotBalloon. During the additional roof ablation by the HotBalloon, sudden hemoptysis developed. It was observed that a guidewire advanced far distal to the left superior pulmonary vein (LSPV) branch. The pulmonary vein angiography demonstrated LSPV branch injury. After activated clotting time control, the hemoptysis disappeared spontaneously. The patient was discharged 6 days after the procedure without any sequela.

The feasibility of a Box isolation strategy for non-paroxysmal atrial fibrillation in elderly patients.

BACKGROUND: Catheter ablation of non-paroxysmal atrial fibrillation (non-PAF) is a therapeutic challenge especially in elderly patients. This study describes the feasibility of a posterior left atrium isolation as a substrate modification in addition to pulmonary vein isolation, the so-called Box isolation, for elderly patients with non-PAF. METHODS: Two hundred twenty-nine consecutive patients who underwent Box isolations for drug-refractory non-PAF were divided into two groups according to their age; younger group comprising 175 patients aged <75 years and elderly group comprising 54 patients aged ≥75 years. RESULTS: During 23.7±12.0 months of follow-up, the arrhythmia-free rates after one procedure were 53.1% in younger group versus 48.1% in elderly group (p=0.50). Following the second procedure, all patients had electrical conduction recoveries along the initial Box lesion. However, a complete Box re-isolation was highly established in both age groups (87.1% vs. 92.9%, respectively; p=1.00). Recurrence of macro-reentrant atrial tachycardia was mainly associated with the gaps through the initial Box lesion in both age groups (25.8% vs. 21.4%, p=1.00), but typical cavo-tricuspid isthmus (CTI) dependent atrial flutter was significantly observed in the elderly patients' group only (all events were observed within 6 months after the initial procedure; 3.2% vs. 28.6%, p=0.009). After two procedures, the arrhythmia-free rates increased to 73.1% in younger group versus 66.7% in elderly group (p=0.38). The occurrence rate of procedural-related complications did not differ between the two age groups, and there were no life-threatening complications even in elderly patients. CONCLUSIONS: Box isolation of non-PAF is effective and safe even in elderly patients. A prophylactic CTI ablation combined with Box isolation might be feasible to improve the long-term outcome.

Is It Necessary to Achieve a Complete Box Isolation in the Case of Frequent Esophageal Temperature Rises? Feasibility of Shifting to a Partial Box Isolation Strategy for Patients With Non-Paroxysmal Atrial Fibrillation.

INTRODUCTION: There are some cases with frequent luminal esophageal temperature (LET) rises despite titrating the radiofrequency energy while creating a linear lesion for the Box isolation of atrial fibrillation (AF). Little is known about the feasibility of redesigning the ablation lines for a modified Box isolation strategy to prevent fatal esophageal injury in those cases. METHODS AND RESULTS: Two hundred and seventeen patients who underwent a Box isolation of non-paroxysmal AF were evaluated. We divided them into 2 groups, patients in whom a box lesion set of the entire posterior left atrium had been achieved (complete Box isolation [CBI]; n = 157) and those in whom 2 additional peri-esophageal vertical lines were created at both the right and left ends of the esophagus, and those areas were left with an incomplete isolation when frequent rapid LET rises above 39.0 °C were observed while creating the floor line (partial Box isolation [PBI]; n = 60). During 20.1 ± 13.9 months of follow-up, the arrhythmia-free rates were 54.1% in the CBI group versus 48.3% in the PBI group (P = 0.62). In the second session, a complete Box isolation was highly achieved even in the PBI group (94.3% vs. 83.3%, respectively; P = 0.17) and after 2 procedures, the arrhythmia-free rates increased to 75.2% vs. 68.3%, respectively (P = 0.34). There was no symptomatic esophageal injury in the PBI group. CONCLUSION: In the case of frequent LET rises while creating the linear lesions for the Box isolation strategy for non-paroxysmal AF, shifting to the PBI strategy was feasible.

Remote Supratentorial Hemorrhage following Supratentorial Craniotomy: A Case Report.

Intracranial hemorrhage (ICH) in regions remote from the initial intracranial operation site is rare. The mechanism of ICH following cranial surgery remains unclear, although several theories have been proposed. Most of the reports describe cerebellar hemorrhages after supratentorial procedures or supratentorial hemorrhages after infratentorial procedures. Remote supratentorial hemorrhage (RSH) following supratentorial surgery is extremely rare. We report a case of postoperative RSH occurring away from the surgical site. A 62-year-old woman underwent a right occipital lobectomy to resect lung carcinoma metastases. The patient developed a postoperative consciousness disturbance, and a brain computed tomography (CT) scan revealed an ICH in the left frontal region. The patient underwent ICH evacuation, but remained severely disabled. It is necessary to be aware that this complication is possible after craniotomy.

Long-Term Results of Radiofrequency Hot Balloon Ablation in Patients With Paroxysmal Atrial Fibrillation: Safety and Rhythm Outcomes.

INTRODUCTION: Isolation of pulmonary veins (PVs) and the posterior left atrium (LA) can be safely performed by radiofrequency hot balloon (RHB)-based box isolation. However, data on long-term effects for the treatment of atrial fibrillation (AF) by the use of this method remain limited. METHODS AND RESULTS: We treated 238 patients with paroxysmal AF (194 male; age. 62.6 ± 9.4 years) by RHB ablation. During 6.2-year (75 months) follow-up, 154 (64.7%) patients were free from atrial tachyarrhythmias (ATAs) without antiarrhythmic-drugs (AADs). We performed re-ablation in 69 of 84 patients with ATA recurrence (average 1.3 ± 0.6; median 1, total 91 procedures) using a 3D-mapping system and a conventional catheter. The sites of reconnection were observed at the PV in 61 of 69 (88.4%) patients and at the posterior LA in 58 of 69 (84.1%) patients. Finally, during mean follow-up of 4.6 ± 1.6 years, no-ATA episodes were detected in 201 (84.5%) patients without AADs. Independent predictors of ATA recurrence following a single procedure were heart failure with preserved ejection fraction (HR: 2.67, 95%CI: 1.40-5.10, P = 0.003) and low estimated glomerular filtration rate (HR: 1.81, 95%CI: 1.11-2.93, P = 0.03; cut-off of 62.0 mL/min/1.73 m(2)). During the follow-up period, there were 4 (1.7%) patients with PV stenosis (>70% reduction in PV diameter); however, none of these cases required intervention. Phrenic nerve palsy was detected in 8 patients (3.4%), but resolved during 3 months in all cases. CONCLUSION: RHB ablation can be effective during a long-term follow-up for patients with paroxysmal AF. Safety outcomes were within an acceptable range.

Reactivity of zirconia with phosphate-bonded investments for hot-pressing.

PURPOSE: The aim of the present study was to investigate the reactivity of zirconia to phosphate-bonded investment on the process of hot-pressing technique. METHODS: Disc-shaped specimens, 16 mm diameter and 0.4mm thick were prepared by cutting and grinding. These specimens were finally sintered. Half of them were sandblasted. The non-sandblasted specimens were used for controls. Both of zirconia discs with and without sandblasting were invested into the three kinds of phosphate-bonded investment. The investments were fired and broken to take out specimens. The biaxial strengths were measured in the way of the biaxial flexural tests according to ISO-6872. RESULTS: The biaxial strengths were ranged 762-1200 MPa at the average. The biaxial strengths of sandblasted zirconia discs heated with phosphate-bonded investment were decreased significantly (p < 0.01). SEM and EPMA revealed that the various compounds were observed on the sandblasted specimens. XRD revealed that surfaces of specimens heated with the phosphate-bonded investment showed the formation of phosphate compounds. CONCLUSIONS: The phosphate compounds inhibit stress-induction phase transformation of zirconia and decrease the biaxial strength.

A three-dimensional finite element evaluation of magnetic attachment attractive force and the influence of the magnetic circuit.

The finite element method has been considered to be excellent evaluative technique to study magnetic circuit optimization. The present study analyzed and quantitatively evaluated the different effects of magnetic circuit on attractive force and magnetic flux density using a three-dimensional finite element method for comparative evaluation. The diameter of a non-magnetic material in the shield disk of a magnetic assembly was variably increased by 0.1 mm to a maximum 2.0 mm in this study design. The analysis results demonstrate that attractive force increases until the diameter of the non-magnetic spacing material reaches a diameter of 0.5 mm where it peaks and then decreases as the overall diameter increases over 0.5 mm. The present analysis suggested that the attractive force for a magnetic attachment is optimized with an appropriate magnetic assembly shield disk diameter using a non-magnetic material to effectively change the magnetic circuit efficiency and resulting retention.

A finite element evaluation of mechanical function for 3 distal extension partial dental prosthesis designs with a 3-dimensional nonlinear method for modeling soft tissue.

STATEMENT OF PROBLEM: The mechanical evaluation of the function of partial removable dental prostheses with 3-dimensional finite element modeling requires the accurate assessment and incorporation of soft tissue behavior. The differential behaviors of the residual ridge mucosa and periodontal ligament tissues have been shown to exhibit nonlinear displacement. The mathematic incorporation of known values simulating nonlinear soft tissue behavior has not been investigated previously via 3-dimensional finite element modeling evaluation to demonstrate the effect of prosthesis design on the supporting tissues. PURPOSE: The purpose of this comparative study was to evaluate the functional differences of 3 different partial removable dental prosthesis designs with 3-dimensional finite element analysis modeling and a simulated patient model incorporating known viscoelastic, nonlinear soft tissue properties. MATERIAL AND METHODS: Three different designs of distal extension removable partial dental prostheses were analyzed. The stress distributions to the supporting abutments and soft tissue displacements of the designs tested were calculated and mechanically compared. RESULTS: Among the 3 dental designs evaluated, the RPI prosthesis demonstrated the lowest stress concentrations on the tissue supporting the tooth abutment and also provided wide mucosa-borne areas of support, thereby demonstrating a mechanical advantage and efficacy over the other designs evaluated. CONCLUSIONS: The data and results obtained from this study confirmed that the functional behavior of partial dental prostheses with supporting abutments and soft tissues are consistent with the conventional theories of design and clinical experience. The validity and usefulness of this testing method for future applications and testing protocols are shown.

Serial intravascular ultrasound assessment of very late stent thrombosis after sirolimus-eluting stent placement.

PURPOSE: In-stent restenosis has been decreasing through the introduction of drug-eluting stents (DES). On the other hand, adverse events such as very late stent thrombosis (VLST) and late catch-up phenomenon can occur especially with sirolimus-eluting stents (SES, first-generation DES) in long-term follow-up. However, the precise mechanisms underlying VLST have not been well investigated in vivo. METHODS AND RESULTS: From 2004 to 2010, 2034 SES were implanted in 1656 patients and caused eight VLST (0.48% per patient) at Fukuoka Tokushukai Medical Center. Of these, serial intravascular ultrasound (IVUS) images (post-stent implantation and at the time of VLST onset) were obtained from three patients with VLST. Comparing them with eight control patients with SES implanted, the vascular reactivity of VLST patients was analyzed. Eight VLST happened 50 ± 15 months after stent implantation and three of the eight patients with VLST had not taken aspirin daily. There were no differences in minimum stent area, maximum external elastic membrane (EEM) area, and stent edge (distal and proximal) EEM area in post-procedural IVUS images. Compared with the control group patients, ΔEEM area (10.6 ± 3.4mm(2) vs. 1.7 ± 1.9 mm(2), p=0.01) and vessel expansion ratio (185.6 ± 40.3% vs. 112.0 ± 12.1%, p=0.01) were significantly greater in the VLST group based on the greater peri-stent plaque expansion (262.1 ± 72.8% vs. 118.7 ± 21.2%, p=0.01). CONCLUSION: Our serial IVUS study showed that the vascular positive remodeling after SES implantation is one of the most probable morphological mechanisms for VLST development.

The influence of a glucosyltransferase, encoded by gtfP, on biofilm formation by Streptococcus sanguinis in a dual-species model.

Streptococcus sanguinis is an early colonizer of tooth surfaces and forms biofilms with other species of microorganisms. In vitro, S. sanguinis produces water-soluble glucans from sucrose and releases them into the culture supernatant; however, the role played by these glucans in biofilm formation is unclear. The present study examined both the effect of glucans on biofilm formation by S. sanguinis and the proportion of this bacterial species within the biofilms. Inactivation of the gtfP gene, annotated as glucosyltransferase in the S. sanguinis genome database, caused a marked reduction in the amount of water-soluble glucans in the culture supernatant, but not in the amount of water-insoluble glucans expressed on the bacterial cell surface. Scanning electron microscopy revealed that wild-type S. sanguinis, but not the gtfP-deficient mutant, produced large amounts of sticky material in the presence of 1% (w/v) sucrose. In addition, biofilm production by wild-type bacteria was greater than that by the mutant strain. By contrast, co-culture of mutant bacteria with Streptococcus mutans, S. sobrinus, S. oralis, S. gordonii, S. anginosus, or S. salivarius showed that inactivating the gtfP gene had little effect on the amount of biofilm produced. Furthermore, inactivating the gtfP gene did not greatly alter the proportion of S. sanguinis in the biofilms formed by the co-cultures. Thus, despite the role of S. sanguinis glucosyltransferase in formation of water-soluble glucans and biofilms in monoculture, the functional gene contributed little to biofilms in co-culture experiments.

Fatty acid profiles and adipogenic gene expression of various fat depots in Japanese Black and Holstein steers.

Objective of the study was to assess the breed effect on fatty acid (FA) composition of different adipose tissues and on mRNA expression of genes involved in adipogenesis and fat metabolism. Japanese Black (JB) and Holstein (HS) steers were kept under equivalent conditions with high energy intake resulting in large differences in intramuscular fat (IMF) accumulation in longissimus muscle (LM). The relative FA composition of muscle, intermuscular fat, visceral fat, and perirenal fat was comparable between JB and HS steers. Circulating fatty acids were also similar in both breeds. Most relevant breed effects were identified in IMF, underlining the uniqueness of this adipose tissue site. JB steers had more monounsaturated FA and less saturated FA. Perilipin 1 and adipose differentiation-related protein (ADFP) mRNA levels were higher in IMF of JB. The results suggest advanced maturity of IMF cells in JB and altered local conditions in muscle influencing IMF accumulation and composition.

Dynamic wetting at the nanoscale.

Although the capillary spreading of a drop on a dry substrate is well studied, understanding and describing the physical mechanisms that govern the dynamics remain challenging. Here we study the dynamics of spreading of partially wetting nanodroplets by combining molecular dynamics simulations and continuum phase field simulations. The phase field simulations account for all the relevant hydrodynamics, i.e., capillarity, inertia, and viscous stresses. By coordinated continuum and molecular dynamics simulations, the macroscopic model parameters are extracted. For a Lennard-Jones fluid spreading on a planar surface, the liquid slip at the solid substrate is found to be significant, in fact crucial for the motion of the contact line. Evaluation of the different contributions to the energy transfer shows that the liquid slip generates dissipation of the same order as the bulk viscous dissipation or the energy transfer to kinetic energy. We also study the dynamics of spreading on a substrate with a periodic nanostructure. Here it is found that a nanostructure with a length scale commensurate with molecular size completely inhibits the liquid slip. The dynamic spreading is thus about 30% slower on a nanostructured surface compared to one that is atomically smooth.

Three-dimensional finite element stress analysis: the technique and methodology of non-linear property simulation and soft tissue loading behavior for different partial denture designs.

The purpose of this study was to develop and report upon a methodology for a non-linear capacity 3D modeling finite element analysis evaluating the loading behavior of different partial denture designs. A 3D finite element model using human CT data was constructed. An original material constant conversion program was implemented in the data simulation of non-linear tissue behavior. The finite element method material properties of residual ridge mucosa were found to have seven material constants and six conversion points of stress values. Periodontal tissues were found to have three constants, and two conversion points. Three magnetic attachment partial denture designs with different bracing elements were evaluated. Technical procedures for finite element model simulation of nonlinear tissue behavior properties evaluating the oral behavior of prosthetic device designs are reported for prosthodontic testing. The use of horizontal cross-arch bracing positively impacts upon the comparative stability of the partial denture designs tested.