Association of oral care with periodontitis and glycemic control among US adults with diabetes.

BACKGROUND: Studies indicate that treating periodontitis may benefit glycemic control among people with diabetes. It is unclear whether oral self-care such as flossing may reduce risk for periodontitis and improve glycemic control among people with diabetes. The purpose of this study was to examine associations between oral care, specifically, flossing and preventive dental care, with periodontitis and glycemic control, among US dentate adults with diabetes. METHODS: We analyzed data from the National Health and Nutrition Examination Survey 2011-2014 for 892 participants aged 30 years and older with diabetes who completed the periodontal examination and lab test for hemoglobin A1c (HbA1c). Sampling weights were applied. Multivariable logistic regression and multivariable linear modeling were performed to examine the associations of flossing and preventive dental services on periodontal health and HbA1c levels, respectively, controlling for sociodemographic characteristics, health behaviors, and other risk factors. RESULTS: Among U.S. dentate adults with diabetes, 52.1% of flossers and 72.1% of non-flossers had periodontitis (p < 0.001). Flossers were 39% less likely to have periodontitis (Adj. OR 0.61, 95% CI 0.43-0.88) compared to non-flossers. Flossers had an average HbA1c reading 0.30% (95% CI 0.02%-0.58%) lower than non-flossers, adjusted for covariates (p = 0.037). Preventive dental visits were associated with reduced risk for periodontitis (Adj. OR 0.54, 95%CI, 0.38-0.75) but not glycemic control. CONCLUSION: Flossing was associated with periodontal health and glycemic control among US adults with diabetes. Although further research is needed, the findings support that oral self-care may be particularly beneficial for adults with diabetes.

Disparities in Preventive Oral Health Care and Periodontal Health Among Adults With Diabetes.

INTRODUCTION: People with diabetes are more vulnerable to periodontal disease than those without; thus, practicing preventive oral health care is an important part of diabetes self-care. Our objective was to examine disparities in preventive oral health care among US adults with diabetes. METHODS: We performed a secondary analysis of data from the National Health and Nutrition Examination Survey (NHANES) 2011-2016. Periodontal examinations were conducted in adults aged 30 and older. We compared the weighted prevalence of periodontal disease and the practice of preventive oral health care, including practicing dental interproximal cleaning (flossing or using other interproximal cleaning devices) and use of preventive dental services, among people with and without diabetes. Multivariable logistic regressions were performed to examine the relationship between the presence of diabetes, periodontal disease, and preventive oral health care practices. RESULTS: Weighted prevalence of periodontal disease in the US population was higher among adults with diabetes than those without (58.0% vs 37.6%). This difference persisted after controlling for sociodemographic characteristics and smoking status. People with diabetes were more likely to have periodontal disease (adjusted odds ratio [aOR] 1.39; 95% CI, 1.17-1.65), less likely to practice daily interproximal cleaning (aOR 0.85; 95% CI, 0.75-0.95), and less likely to visit a dentist for preventive care in the past year (aOR 0.86; 95% CI, 0.76-0.96) than people without diabetes. CONCLUSION: Adults with diabetes reported suboptimal preventive oral health care behaviors in use of preventive dental services and interproximal dental cleaning than people without diabetes, despite their health disparity related to periodontal disease. Educating people to improve their preventive oral health care is essential for good oral health and diabetes self-management.

Advancing Tissue Damage Repair in Geriatric Diseases: Prospects of Combining Stem Cell-Derived Exosomes with Hydrogels.

Geriatric diseases are a group of diseases with unique characteristics related to senility. With the rising trend of global aging, senile diseases now mainly include endocrine, cardiovascular, neurodegenerative, skeletal, and muscular diseases and cancer. Compared with younger populations, the structure and function of various cells, tissues and organs in the body of the elderly undergo a decline as they age, rendering them more susceptible to external factors and diseases, leading to serious tissue damage. Tissue damage presents a significant obstacle to the overall health and well-being of older adults, exerting a profound impact on their quality of life. Moreover, this phenomenon places an immense burden on families, society, and the healthcare system.In recent years, stem cell-derived exosomes have become a hot topic in tissue repair research. The combination of these exosomes with biomaterials allows for the preservation of their biological activity, leading to a significant improvement in their therapeutic efficacy. Among the numerous biomaterial options available, hydrogels stand out as promising candidates for loading exosomes, owing to their exceptional properties. Due to the lack of a comprehensive review on the subject matter, this review comprehensively summarizes the application and progress of combining stem cell-derived exosomes and hydrogels in promoting tissue damage repair in geriatric diseases. In addition, the challenges encountered in the field and potential prospects are presented for future advancements.

Multiple Chronic Diseases Associated With Tooth Loss Among the US Adult Population.

Background: Half of US adults aged 20-64 years have lost at least one permanent tooth; one in six adults aged 65 and over in the USA is edentulous. Tooth loss and edentulism interfere with nutritional intake and quality of life. Although selected chronic diseases (e.g., diabetes) have been identified as possible risk factors for tooth loss, data on multiple chronic diseases and on having two or more concurrent chronic diseases (multimorbidity) in relation to tooth loss are lacking. Therefore, this study aimed to assess the association between multiple chronic diseases, multimorbidity, and tooth loss in US adults. Methods: We performed a secondary data analysis using the US 2012 Behavioral Risk Factor Surveillance System (BRFSS), a national cross-sectional telephone survey studying health conditions and health behaviors among US adults (≥18 years) who are non-institutionalized residents. Variables were derived from the BRFSS Standard Core Questionnaire. Descriptive analysis including means, standard deviations (SDs), and percentages was calculated. Sample weights were applied. The stepwise multinomial logistic regression method was used to examine the relationship between several chronic diseases and tooth loss. Separate multinomial logistic regression models were used to examine the relationship between multimorbidity and tooth loss among all adults aged more than 18 years, adults aged 18-64 years, and adults aged more than 65 years, respectively. Results: Among the samples (n = 471,107, mean age 55 years, 60% female), 55% reported losing no tooth loss, 30% reported losing one to five teeth, 10% reported losing six or more but not all teeth, and 5% reported losing all teeth. After adjusting for demographic characteristics, socioeconomic status, smoking, BMI, and dental care, chronic diseases that were associated with edentulism were chronic obstructive pulmonary disease (COPD) [adjusted risk ratio (adj. RR) 2.18, 95% confidence interval (CI) 2.08-2.29]; diabetes (adj. RR 1.49, 95% CI 1.44-1.56); arthritis (adj. RR 1.49, 95% CI 1.44-1.54); cardiovascular disease (adj. RR 1.38, 95% CI 1.30-1.45); stroke (adj. RR 1.31, 95% CI 1.24-1.40); kidney disease (adj. RR 1.16, 95% CI 1.08-1.25); cancer (adj. RR 1.05, 95% CI 1.01-1.11); and asthma (adj. RR 1.07, 95% CI 1.02-1.12). For those who reported losing six or more teeth, the association remained significant for all the chronic diseases mentioned, albeit the magnitude of association appeared to be comparative or smaller. In addition, adults with multimorbidity were more likely to have tooth loss (loss of one to five teeth: adj. RR 1.17, 95% CI 1.14-1.19; loss of six or more teeth: adj. RR 1.78, 95% CI 1.73-1.82; edentulous: adj. RR 2.03, 95% CI 1.96-2.10). Conclusions: Multiple chronic diseases were associated with edentulism and tooth loss. People with multimorbidity are more likely to be edentulous than those with one or no chronic disease. The findings from this study will help to identify populations at increased risk for oral problems and nutritional deficits, thus the assessment of oral health should be evaluated further as an important component of chronic illness care.

Dental Caries Status in Autistic Children: A Meta-analysis.

The objective of this meta-analysis was to assess the dental health status of children with ASD in terms of decayed, missing, and filled permanent teeth (DMFT) and decayed, missing, and filled deciduous teeth (dmft). PubMed, Embase, psycINFO, and Cochrane library were searched for studies published until September 2018. A random-effects model was applied to estimate the pooled results.Nine studies comprising 532 children with ASD and 622 controls were included. No significant differences between children with ASD and controls were observed for DMFT and dmft in the world. Subgroup analyses revealed that children with ASD had a significantly higher dmft index than that of controls in Asia.Children with ASD have a worse dental health status than healthy children in Asia, but caution is necessary given the limited studies available for analysis.

Methane oxidation coupled to perchlorate reduction in a membrane biofilm batch reactor.

A specially designed CH4-based membrane biofilm batch reactor (MBBR) was applied to investigate anaerobic methane oxidation coupled to perchlorate reduction (AnMO-PR). The 0.21 mM ClO4- added in the first stage of operation was completely reduced in 28 days, 0.40 mM ClO4- was reduced within 23 days in stage 2, and 0.56 mM of ClO4- was reduced within 30 days in stage 3. Although some chlorate (ClO3-) accumulated, the recovery of Cl- was over 92%. Illumina sequencing of the 16S rRNA gene documented that the bacterial community was mainly composed by perchlorate-reducing bacteria (PRB), methanotrophic bacteria, and archaea. Real-time quantitative PCR showed the archaeal 16S rRNA and mcrA genes increased as more ClO4- was reduced, and the predominant archaea belonged to Methanosarcina mazei, which is related to ANME-3, an archaeon able to perform reverse methanogenesis. Several pieces of evidence support that ClO4- reduction by the MBBR biofilm occurred via a synergism between Methanosarcina and PRB: Methanosarcina oxidized methane through reverse methanogesis and provided electron donor for PRB to reduce ClO4-. Because methanotrophs were present, we cannot rule out that they also were involved in AnMO-PR if they received O2 generated by disproportionation of ClO2- from the PRB.

Dissolved oxygen has no inhibition on methane oxidation coupled to selenate reduction in a membrane biofilm reactor.

Methane oxidation coupled to selenate reduction has been suggested as a promising technology to bio-remediate selenium contaminated environments. However, the effect of dissolved oxygen (DO) on this process remained unclear. Here, we investigate the feasibility of selenate removal at two distinct DO concentrations. A membrane biofilm reactor (MBfR) was initially fed with ∼5 mg Se/L and then lowered to ∼1 mg Se/L of selenate, under anoxic condition containing ∼0.2 mg/L of influent DO. Selenate removal reached approximately 90% without selenite accumulation after one-month operation. Then 6-7 mg/L of DO was introduced and showed no apparent effect on selenate reduction in the subsequent operation. Electron microscopy suggested elevated oxygen exposure did not affect microbial shapes. 16S rDNA sequencing showed the aerobic methanotroph Methylocystis increased, while possible selenate reducers, Ignavibacterium and Bradyrhizobium, maintained stable after oxygen boost. Gene analysis indicated that nitrate/nitrite reductases positively correlated with selenate removal flux and were not remarkably affected by oxygen addition. Reversely, enzymes related with aerobic methane oxidation were obviously improved. This study provides a potential technology for selenate removal from oxygenated environments in a methane-based MBfR.

Formation of nanoscale Te0 and its effect on TeO32- reduction in CH4-based membrane biofilm reactor.

Formation and recovery of elemental tellurium (Te0) from wastewaters are required by increasing demands and scarce resources. Membrane biofilm reactor (MBfR) using gaseous electron donor has been reported as a low-cost and benign technique to reduce and recover metal (loids). In this study, we demonstrate the feasibility of nanoscale Te0 formation by tellurite (TeO32-) reduction in a CH4-based MBfR. Biogenic Te0 intensively attached on cell surface, within diameters ranging from 10 nm to 30 nm and the hexagonal nanostructure. Along with the Te0 formation, the TeO32- reduction was inhibited. After flushing, biofilm resumed the TeO32- reduction ability, suggesting that the formed nanoscale Te0 might inhibit the reduction by hindering substrate transfer of TeO32- to microbes. The 16S rRNA gene amplicon sequencing revealed that Thermomonas and Hyphomicrobium were possibly responsible for TeO32- reduction since they increased consecutively along with the experiment operation. The PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) analysis showed that the sulfite reductases were positively correlated with the TeO32- flux, indicating they were potential enzymes involved in reduction process. This study confirms the capability of CH4-based MBfR in tellurium reduction and formation, and provides more techniques for resources recovery and recycles.

Investigation of thermodynamic properties of poly(methyl methacrylate-co-n-butylacrylate-co-cyclopentyl styryl-polyhedral oligomeric silsesquioxane) by inverse gas chromatography.

The thermodynamic properties of poly(methyl methacrylate-co-butyl acrylate-co-cyclo -pentylstyryl polyhedral oligomeric silsesquioxane) (poly(MMA-co-BA-co-styryl-POSS)) were investigated by means of inverse gas chromatography (IGC) using 20 different kinds of solvents as the probes. Some thermodynamic parameters, such as molar heats of sorption, weight fraction activity coefficient, Flory-Huggins interaction parameter, partial molar heats of mixing and solubility parameter were obtained to judge the interactions between POSS-contained polymers and solvents and the solubility of the polymers in these solvents. It was found that acetates, aromatic hydrocarbons and hydrocarbon halides were good solvents, n-hexane, ethanol, n-propanol, n-butanol and n-pentanol were moderate solvents, while n-heptane, n-octane, n-nonane, n-decane and methanol were poor solvents for all POSS-contained polymers within the experimental temperature range. Incorporation of POSS in polymer increased the solubility of polymers in solvents, and the more the POSS in polymer was, the better the solubility was and stronger the hydrogen bonding interaction was, but the POSS content in polymers seemed to have no obvious influence on the solubility parameter of polymers.

Surface characterization of poly(methyl methacrylate-co-n-butyl acrylate-co-cyclopentylstyryl-polyhedral oligomeric silsesquioxane) by inverse gas chromatography.

The surface properties of poly(methyl methacrylate-co-n-butyl acrylate-co-cyclopentylstyryl polyhedral oligomeric silsesquioxane) (poly(MMA-co-BA-co-styryl-POSS)) were studied by means of inverse gas chromatography (IGC) using 10 non-polar and polar solvents as the probes. Thermodynamic parameters of adsorption, e.g., specific retention volume, the dispersive component of the surface free energy, the specific interaction contribution to the free energy of adsorption and the acid/base constants were obtained to investigate the interactions between the surfaces of the copolymers and different solvents. It was found that incorporation of styryl-POSS into polymer resulted in increasing interactions between polymers and solvents, dispersive component of surface free energy of polymer and acidity of the surfaces of the polymers. The more the styryl-POSS were embedded, the stronger the interaction between the polymer surface and solvent, the dispersive component of the surface free energy and the acidity of the polymer surface were.

[The effect of entrapment of CpG sequence with cationic PLG nanoparticles on the immune responses of mice to pig paratyphoid vaccine].

Cationic PLG nanoparticles and liposome were prepared and used as package molecules to pack up pUC18-CpG. The effects of the packed pUC18-CpG on the cellular and humoral immune responses were detected in the mice that were inoculated with pig paratyphoid vaccine. The results showed that compared with the control, the amount of IgG and the titre of specific antibody were significantly increased in the sera of mice immunized with the CpG plasmid entrapped by cationic PLG nanoparticles; the proliferation and induced IL-2 bioactivity of lymphocytes were significantly enhanced in the spleen of the immunized mice; the stimulatory effect of cationic PLG nanoparticles was similar to or stronger than that of cationic liposome. These indicated that cationic PLG nanoparticle could be employed as an effective package molecule to promote the immunostimulatory effect of pUC18-CpG.

Mechanical properties and corrosion behavior of Mg-Gd-Ca-Zr alloys for medical applications.

Magnesium alloys are promising candidates for biomedical applications. In this work, influences of composition and heat treatment on the microstructure, the mechanical properties and the corrosion behavior of Mg-Gd-Ca-Zr alloys as potential biomedical implant candidates were investigated. Mg5Gd phase was observed at the grain boundaries of Mg-10Gd-xCa-0.5Zr (x=0, 0.3, 1.2wt%) alloys. Increase in the Ca content led to the formation of additional Mg2Ca phase. The Ca additions increased both the compressive and the tensile yield strengths, but reduced the ductility and the corrosion resistance in cell culture medium. After solution heat treatment, the Mg5Gd particles dissolved in the Mg matrix. The compressive strength decreased, while the corrosion resistance improved in the solution treated alloys. After ageing at 200°C, metastable ß' phase formed on prismatic planes and a new type of basal precipitates have been observed, which improved the compressive and tensile ultimate strength, but decreased the ductility.

Morphological changes of frankel functional regulator III in mixed dentition with class III malocclusion / Cambios morfológicos del regulador funcional frankel III en dentición mixta con maloclusión clase III

The aim of this study was to evaluate the hard and soft tissue profile changes following treatment of functional and mild skeletal class III malocclusion in mixed dentition by means of the Frankel functional regulator (FR-3) appliance, and to reveal the mechanism and effectiveness of treatment with FR-3 appliance. Twenty-six patients (chronological mean age, 8.7±1.4 years; mean treatment duration, 10.3±1.3 months) with functional and mild skeletal class III malocclusion were selected and treated with FR-3 appliances. Lateral cephalogram was taken pre- and post-treatment, and the data was analyzed by paired-samples t test with SPSS22.0 software package. Differences were considered statistically significant at P < 0.05. The results demonstrated that the FR-3 appliance produced a statistically significant decrease in L1-NB, L1-MP, U1-L1 (P<0.01) and an increase greatly in ANB, MP-FH, Y axis, ANSMe, ANS-Me/N-Me and overjet (P<0.01). SNA, SNB were increased significantly (P<0.05). Meanwhile, N'-Sn-Pog', ULSn-SN, LLSiSN increased, S-N'-Si, LL-EP decreased with significant difference (P<0.01). S-N'-Sn, Cm-Sn-UL, UL-EP, Sn-Mes and Ns-Mes increased with significant difference (P<0.05). Therefore it was concluded that after FR-3 treatment, the position of mandible may rotate clockwise backwards and downwards, with the labioversion of upper incisors and linguoversion of lower incisors. Although point A moved mesially, the length and position of the maxilla did not change significantly. With the protrusion of upper lip and the retrusion of lower lip, the relationship among nose, upper lip, lower lip and chin become harmonious, the profile of soft tissue is more coordinated and attractive.

El objetivo de este estudio fue evaluar los cambios en el perfil de los tejidos duros y blandos después del tratamiento de la maloclusión funcional y leve de la clase III esquelética en la dentición mixta mediante el aparato regulador funcional Frankel (FR-3), y revelar el mecanismo y efectividad del tratamiento con el aparato FR-3. Veintiseis pacientes (edad media 8,7 ± 1,4 años; duración media del tratamiento, 10,3 ± 1,3 meses) con maloclusión funcional y leve de clase esquelética III fueron seleccionados y tratados con aparatos FR-3. El cefalograma lateral se tomó antes y después del tratamiento, y los datos se analizaron mediante la prueba t de muestras con el software SPSS22.0. Las diferencias se consideraron estadísticamente significativas a P <0,05. Los resultados demostraron que el dispositivo FR-3 produjo una disminución estadísticamente significativa en L1-NB, L1MP, U1-L1 (P <0,01) y un gran aumento en ANB, MP-FH, eje Y, ANS-Me, ANS -Me / N-Me y overjet (P <0,01). SNA, SNB se incrementaron significativamente (P <0,05). Mientras tanto, N'Sn-Pog', ULSn-SN, LLSi-SN aumentaron, S-N'-Si, LL-EP disminuyeron con una diferencia significativa (P <0,01). S-N'-Sn, Cm-Sn-UL, UL-EP, Sn-Mes y Ns-Mes aumentaron con una diferencia significativa (P <0,05). Por lo tanto, se concluyó que después del tratamiento con FR-3, la posición de la mandíbula puede girar en sentido reloj hacia atrás y hacia abajo, con labioversión de los incisivos superiores y linguoversión de los incisivos inferiores. Aunque el punto A se movió mesialmente, la longitud y la posición del maxilar no cambiaron significativamente. Con la protuberancia del labio superior y la retrusión del labio inferior, la relación entre la nariz, el labio superior, el labio inferior y el mentón se armoniza, el perfil del tejido blando es más coordinado y atractivo.

Tribological properties of Zr61Ti2Cu25Al12 bulk metallic glass under simulated physiological conditions.

In this work, wear resistance of a Zr61Ti2Cu25Al12 (ZT1) bulk metallic glass (BMG) in dry-sliding and simulated physiological media was investigated using ball-on-flat tribological approach and Si3N4 ball as counterpart. It was indicated that wear resistance of the BMG in air and deionized water is superior to Ti6Al4V alloy but inferior to 316L stainless steel (316L SS) and Co28Cr6Mo (CoCrMo) alloy. However, under simulated physiological media such as phosphate buffered solution (PBS) and Dulbecco's modified Eagle medium with 10vol.% fetal bovine serum (DMEM+FBS), the ZT1 BMG exhibits decreased wear resistance in comparison with the Ti6Al4V, 316L SS and CoCrMo. This is probably associated with its moderate pitting corrosion resistance in the medium containing chloride ions. The presence of protein in the solution has a significant effect to ruin pitting resistance of the BMG, then causing more severe wear damage. Under the dry-wear condition, abrasive wear is a predominant wear mechanism for the ZT1, whereas under deionized water, deterioration induced by abrasive wear can be mitigated. In simulated physiological media, wear deterioration is a typical tribocorrosion controlled by synergistic effects of the abrasive and corrosive wear. For the four investigated metals, wear resistance does not exhibit distinct correlation with hardness, whereas the material with high Young's modulus possesses better wear resistance.

Biodegradable Mg-Zn-Y alloys with long-period stacking ordered structure: optimization for mechanical properties.

To optimize the mechanical properties for biodegradable orthopedic implant, microstructures and tensile properties of Mg-Zn-Y alloys containing long period stacking ordered (LPSO) phase were investigated. For the as-cast Mg(100-3x)(Zn(1)Y(2))(x) (1 ≤ x ≤ 3) alloys, volume fraction of 18R LPSO phase increases with increasing the contents of Zn and Y. Mg(97)Zn(1)Y(2) alloy exhibits the optimal combination of strength and plasticity. Substitution of bioactive element Ca for Y in the Mg(97)Zn(1)Y(2) does not favor the formation of LPSO phase, but involving the formation of Mg(2)Ca phase. By micro-alloying with Zr as grain refinement agent, morphology of α-Mg in the Mg(96.83)Zn(1)Y(2)Zr(0.17) alloy is changed into the equiaxial shape, together with a significant refinement in grain size to 30 µm. It brings about an improvement not only in strength but also in plasticity, in contrast to the Zr-free alloy. In comparison with the as-cast state, warm-extruded alloys manifest significantly improved properties not only in strength but also in plasticity due to the refinement of α-Mg grain by dynamic recrystallization and the alignment of LPSO phase along extrusion direction.

Mg-Zn-Y alloys with long-period stacking ordered structure: in vitro assessments of biodegradation behavior.

Using Dulbecco's modified eagle medium (DMEM) with 10% fetal bovine serum (FBS) as simulated body fluid, degradation behavior of Mg100-3x(Zn1Y2)x (1≤x≤3) alloy series with long period stacking order (LPSO) structures was investigated. As indicated, with increasing the volume fraction of LPSO phase, degradation rate of the alloys is accelerated. Further refining the grain size by microalloying with zirconium and warm extrusion has a significant effect to mitigate the degradation rate of the Mg97Zn1Y2 alloy. Time-dependent behavior during degradation of the magnesium alloys can be described using an exponential decay function of WR=exp(a+bt+ct(2)), where WR is normalized residual mass/volume of the alloy. A parameter named as degradation half-life period (t0.5) is suggested to quantitatively assess the degradation rate. For the localized-corrosion controlled alloys, the t0.5 parameter physically scales with electrochemical response ΔE which is a range between corrosion potential (Ecorr) and pitting potential (Ept). In comparison with conventional engineering magnesium alloys such as the AZ31, WE43, ZK60 and ZX60 alloys, extruded Mg96.83Zn1Y2Zr0.17 alloy with LPSO structure exhibits a good combination of high mechanical strength, lower biodegradation rate and good biocompatibility.

Zr61Ti2Cu25Al12 metallic glass for potential use in dental implants: biocompatibility assessment by in vitro cellular responses.

In comparison with titanium and its alloys, Zr61Ti2Cu25Al12 (ZT1) bulk metallic glass (BMG) manifests a good combination of high strength, high fracture toughness and lower Young's modulus. To examine its biocompatibility required for potential use in dental implants, this BMG was used as a cell growth subtract for three types of cell lines, L929 fibroblasts, human umbilical vein endothelial cells (HUVEC), and osteoblast-like MG63 cells. For a comparison, these cell lines were in parallel cultured and grown also on commercially pure titanium (CP-Ti) and Ti6-Al4-V alloy (Ti64). Cellular responses on the three metals, including adhesion, morphology and viability, were characterized using the SEM visualization and CCK-8 assay. Furthermore, real-time RT-PCR was used to measure the activity of integrin ß, alkaline phosphatase (ALP) and type I collagen (COL I) in adherent MG63 cells. As indicated, in all cases of three cell lines, no significant differences in the initial attachment and viability/proliferation were found between ZT1, CP-Ti, and Ti64 until 5d of incubation period. It means that the biocompatibility in cellular response for ZT1 BMG is comparable to Ti and its alloys. For gene expression of integrin ß, ALP and COL I, mRNA level from osteoblast cells grown on ZT1 substrates is significantly higher than that on the CP-Ti and Ti64. It suggests that the adhesion and differentiation of osteoblasts grown on ZT1 are even superior to those on the CP-Ti and Ti64 alloy, then promoting bone formation. The good biocompatibility of ZT1 BMG is associated with the formation of zirconium oxide layer on the surface and good corrosion-resistance in physiological environment.

Mesoscale simulation on patterned nanotube model for amphiphilic block copolymer.

Self-assembly of AB diblock copolymer confined in concentric-cylindrical nanopores was studied using MesoDyn simulation. Our calculation shows that in this confined geometry a zoo of exotic structures can be formed. These structures include bicontinuous phases like carbon nanotube, imperfect single helixes and double helixes. Moreover, the dependence of the chain conformation on the volume fraction, concentration, the interactions between blocks and the diameter of the cylindrical pore are investigated. The results of these simulations can be used to predict the diblock copolymer morphologies confined in concentric-cylindrical nanopores and should be helpful in designing polymeric nanomaterials in the future.

[Effects of tobacco on rat gingival fibroblats attaching to titanium].

PURPOSE: The study was designed to observe the effects of the smokeless tobacco extract(ST) on the attachment,morphology,structure and proliferation of rat gingival fibroblasts(RGFs) to titanium in vitro. METHODS: RGFs were obtained from explants of rat normal gingival tissues by using tissue-explant technique.The origin of cells was identified by immunochemistry of vimentin and cytokeratin. RGFs to titanium were cultured in the presence of ST at various concentration,the attachment and growth of cells attached to titanium were measured by MTT method, immunofluorescence was used to detect and analyze the shapes of RGFs attached to titanium.Statistical analysis was performed using SPSS13.0 software package for one-way ANOVA. RESULTS: Immunochemical study showed that vimentin was expressed in RGFs while cytokeratin was negative,which indicated that RGFs were originated from mesoblastoma.With the increasing of ST concentration,the attachment,spreading shape and proliferation of RGFs in all groups decreased in a concentration-dependent manner.The difference between ST group and control group was statistically significant(P<0.05). CONCLUSIONS: ST can inhibit the attachment,spreading shape and proliferation of RGFs, suggesting that smoking may have influence on the long result of oral implant operation.

Effects of shear and charge on the microphase formation of P123 polymer in the SBA-15 synthesis investigated by mesoscale simulations.

Mesoscale simulation was performed to investigate the dynamical structural behavior of the pluronic P123 block copolymer in the synthesis of mesoporous SBA-15. Shear is introduced to represent stirring in the actual experiment, and a weak charge is included to simulate the acidic conditions in the synthesis. Under shear, with the increase in weak charge in the PEO [poly(ethylene oxide)] block, the template forms more ordered hexagonal phases, and the pore sizes of the cylindrical hydrophobic PPO [poly(propylene oxide)] blocks decrease. The structural factor shows three types of water molecules in the mesoscale aggregates, including bulk water in the solution, bound water around the hydrophilic PEO corona, and trapped water in the hydrophobic PPO core. When 1,3,5-trimethyl-benzene (TMB) is added to the system as a swelling agent, expanded hexagonal phases are formed, and the density mapping of TMB shows that the TMB molecules are mainly located in the hydrophobic PPO cores. In configurations with spherical micelles, although bimodally dispersed spheres are observed, the face-centered cubic (fcc) packing of the micelles hardly changes with the addition of TMB. In agreement with experimental results, the simulations show that the shear and the weak charge are essential to the formation of hexagonal templates in the copolymer. Mesoscopic simulations complement experimental investigations on the morphology changes of amphiphilic polymer in template syntheses and can provide important guidance for further experiments.