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1.
Shanghai Kou Qiang Yi Xue ; 33(1): 36-39, 2024 Feb.
Article in Chinese | MEDLINE | ID: mdl-38583022

ABSTRACT

PURPOSE: To study the effect of different cleaning methods on the shear bond strength of self-adhesive resin cement to saliva-contaminated high translucency zirconia and surface wettability. METHODS: Eighty zirconia specimens were randomly divided into 5 groups (n=16), i.e., control group(not contaminated), 75% ethanol group,cleaning paste group,airborne-particle abrasion group, and atmospheric pressure cold plasma group. The contact angles was measured, shear bond strength were examined, and fracture types were determined. SPSS 26.0 software package was used for statistical analysis of the data. RESULTS: The atmospheric pressure cold plasma group produced the lowest contact angle(P<0.05). The shear bond strength of the airborne-particle abrasion group, the cleaning paste group and the atmospheric pressure cold plasma group respectively were similar to the control group without significant difference(P>0.05), while those were significantly higher than 75% ethanol group(P<0.05). The mixed fracture mode of the atmospheric pressure cold plasma group evidently increased. CONCLUSIONS: Airborne-particle abrasion, cleaning paste and atmospheric pressure cold plasma overcome the effects of saliva contamination, producing the shear bond strength to zirconia similar to the control group. The atmospheric pressure cold plasma improves hydrophilicity of high translucency zirconia significantly.


Subject(s)
Dental Bonding , Plasma Gases , Wettability , Surface Properties , Resin Cements , Zirconium/chemistry , Ethanol , Materials Testing , Shear Strength , Dental Stress Analysis
2.
J Dent Sci ; 19(1): 39-45, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38303823

ABSTRACT

Background/purpose: The guided protocols always yield a higher accuracy than freehand surgery. However, the accuracy of digital guides for crown lengthening surgery (CLS) is unknown. The purpose of this study was to evaluate the trueness of 3 types of digital guides for CLS. Materials and methods: Twenty individually designed maxillary models were divided into 4 groups according to surgical guides: type I (T1), type II (T2), type III (T3), and free-hand. T1 comprised a planed gingival margin at the tissue level. T2 included both the planed gingival margin and alveolar crest at the tissue level. T3 consisted of a planed gingival margin at the tissue level and an alveolar crest at the bone level. CLS was performed under the indication of the guides. Trueness of the guides was evaluated through the deviation of the gingival zenith and alveolar crest height. Results: The control group had higher vertical and horizontal distance deviations of gingival zenith compared to the 3 digital guide groups (P < 0.001). There were no significant differences among the 3 test groups in terms of gingival zenith deviations (P > 0.05). With regard to height deviation of alveolar crest, the control and T1 groups were higher than T2 group (P < 0.001), while T3 group had the lowest deviations among the 4 groups (P < 0.001). Conclusion: The digital guides assisted CLS procedures are more accurate than free-hand method. The trueness of type III guide was better than type I and type II.

3.
Eur J Med Res ; 29(1): 62, 2024 Jan 20.
Article in English | MEDLINE | ID: mdl-38245805

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is highly prevalent in the population, yet the factors contributing to AF events in susceptible individuals remain partially understood. The potential relationship between meteorological factors and AF, particularly with abnormal electrocardiograph (ECG) repolarization, has not been adequately studied. This case-crossover study aims to investigate the association between meteorological factors and daily hospital visits for AF with abnormal ECG repolarization in Shanghai, China. METHODS: The study cohort comprised 10,325 patients with ECG-confirmed AF who sought treatment at Shanghai Sixth People's Hospital between 2015 and 2018. Meteorological and air pollutant concentration data were matched with the patient records. Using a case-crossover design, we analyzed the association between meteorological factors and the daily count of hospital visitors for AF with abnormal ECG repolarization at our AF center. Lag analysis models were applied to examine the temporal relationship between meteorological factors and AF events. RESULTS: The analysis revealed statistically significant associations between AF occurrence and specific meteorological factors. AF events were significantly associated with average atmospheric pressure (lag 0 day, OR 0.9901, 95% CI 0.9825-0.9977, P < 0.05), average temperature (lag 1 day, OR 0.9890, 95% CI 0.9789-0.9992, P < 0.05), daily pressure range (lag 7 days, OR 1.0195, 95% CI 1.0079-1.0312, P < 0.01), and daily temperature range (lag 5 days, OR 1.0208, 95% CI 1.0087-1.0331, P < 0.01). Moreover, a significant correlation was observed between daily pressure range and daily temperature range with AF patients, particularly those with abnormal ECG repolarization, as evident in the case-crossover analysis. CONCLUSION: This study highlights a significant correlation between meteorological factors and daily hospital visits for AF accompanied by abnormal ECG repolarization in Shanghai, China. In addition, AF patients with abnormal ECG repolarization were found to be more vulnerable to rapid daily changes in pressure and temperature compared to AF patients without such repolarization abnormalities.


Subject(s)
Atrial Fibrillation , Humans , Atrial Fibrillation/epidemiology , Cross-Over Studies , China/epidemiology , Weather , Hospitals , Electrocardiography
4.
J Prosthet Dent ; 2023 Sep 09.
Article in English | MEDLINE | ID: mdl-37696746

ABSTRACT

STATEMENT OF PROBLEM: An accurate digital workflow for transferring the interocclusal relationship from complete arch diagnostic interim restorations to complete arch tooth preparations is essential in complete mouth rehabilitation. However, research on the accuracy of digital cross-mounting methods is lacking. PURPOSE: The purpose of this in vitro study was to compare the trueness of 4 sectional-cast digital cross-mounting methods in transferring the interocclusal relationship for complete mouth rehabilitation. MATERIAL AND METHODS: Maxillary and mandibular anatomic typodonts were used to build complete arch tooth preparations and diagnostic interim restorations for complete mouth rehabilitation in vitro. Four sectional casts were designed: an anterior cast (AR), a posterior cast (PO), a unilateral cast (UL), and a tripod cast (TR). Both extraoral scanning (EOS) and intraoral scanning (IOS) were used to obtain intermediate digital sectional casts, which were cross-registered with diagnostic interim restorations and definitive casts to transfer the interocclusal relationship. Trueness was determined by assessing tooth distance deviation and mandibular 3-dimensional (3D) deviation. Differences among the 4 sectional-cast methods were analyzed with the Kruskal-Wallis test, and differences between the 2 scanning methods were analyzed with the Mann-Whitney U test (α=.05). RESULTS: Significant differences in the trueness of interocclusal relationship transfer were observed among the 4 sectional-cast methods (P<.05). Regarding tooth overall distance deviation, TR-EOS found no statistically significant difference compared with PO-EOS (P>.05), but TR-EOS had half the overall distance deviation of PO-EOS. Both TR-EOS and PO-EOS had smaller deviations than the AR-EOS and UL-EOS groups (P<.05). TR-IOS had a smaller distance deviation than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The overall distance deviation of EOS was significantly smaller than that of IOS in the TR and PO groups (P<.05). Regarding mandibular 3D deviation, TR-EOS found no statistically significant difference but had half the root mean square (RMS) of 3D deviation compared with the PO-EOS groups (P>.05). Both TR-EOS and PO-EOS groups had a smaller RMS than the AR-EOS and groups (P<.05). The TR-IOS group had a smaller RMS than the AR-IOS, PO-IOS, and UL-IOS groups (P<.05). The 3D deviation of EOS was significantly smaller than that of IOS in the PO group (P<.05). CONCLUSIONS: Both EOS and IOS with the tripod sectional-cast digital method accurately transferred the interocclusal relationship for complete mouth rehabilitation.

6.
J Prosthet Dent ; 130(4): 613.e1-613.e8, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37633729

ABSTRACT

STATEMENT OF PROBLEM: The build angle is an essential parameter in additive manufacturing. Its effect on the dimensional accuracy of zirconia restorations fabricated using the nanoparticle jetting (NPJ) technique is unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effect of the build angle on the dimensional accuracy of monolithic zirconia complete crowns fabricated by using NPJ. MATERIAL AND METHODS: Standardized artificial right maxillary incisors and mandibular first molars were prepared for ceramic complete crowns. In total, 100 monolithic zirconia crowns were fabricated using NPJ at build angles of 0, 45, 90, 135, and 180 degrees (n=10/angle for incisors and molars). The dimensional accuracies in the external, marginal, and intaglio regions were determined by superimposing the scanned data and computer-aided design data on the crowns. Root mean square (RMS) values were used to analyze the accuracy of the zirconia crowns overall and at the external, marginal, and intaglio surfaces. The Shapiro-Wilk test was used to examine the normality of data distribution. Differences among test groups were assessed using a 1-way analysis of variance and the post hoc least significant difference test (α=.05). RESULTS: Significant differences were found in the accuracy of monolithic zirconia incisor and molar complete crowns in the external, marginal, and intaglio regions among the 5 build angles (P<.05). For incisors, the external RMS value was lowest for a build angle of 45 degrees (18.2 ±3.0 µm), the marginal and intaglio RMS values were lowest for a build angle of 135 degrees (47.4 ±10.7 and 26.5 ±6.1 µm, respectively), and the overall RMS values did not differ significantly among the 5 build angles (P>.05). For molars, build angles of 0 degrees and 180 degrees yielded the lowest RMS values overall (22.3 ±1.5 and 21.8 ±3.2 µm, respectively) and in the external (23.2 ±2.9 and 22.3 ±2.5 µm, respectively) and intaglio (22.2 ±3.7 and 21.2 ±4.6 µm, respectively) regions. No significant difference was observed in the marginal area among the 5 build angles (P>.05). The overall RMS values reflecting dimensional accuracy for the 5 build angles were between 23.5 and 26.7 µm for incisors and 21.8 and 26.2 µm for molars. CONCLUSIONS: The dimensional accuracy of monolithic zirconia crowns fabricated by using NPJ was affected by the build angle and was within clinically acceptable limits.


Subject(s)
Dental Marginal Adaptation , Dental Prosthesis Design , Dental Prosthesis Design/methods , Computer-Aided Design , Zirconium , Crowns
7.
Eur J Med Res ; 28(1): 201, 2023 Jun 29.
Article in English | MEDLINE | ID: mdl-37381047

ABSTRACT

BACKGROUND: The relationship between air pollution and atrial fibrillation (AF) recorded by electrocardiograph (ECG) has not yet been illustrated which worsens AF precaution and treatment. This research evaluated the association between air pollution and daily hospital visits for AF with ECG records. METHODS: The study enrolled 4933 male and 5392 female patients whose ECG reports indicated AF from 2015 to 2018 in our hospital. Such data were then matched with meteorological data, including air pollutant concentrations, collected by local weather stations. A case-crossover study was performed to assess the relationship between air pollutants and daily hospital visits for AF recorded by ECG and to investigate its lag effect. RESULTS: Our analysis revealed statistically significant associations between AF occurrence and demographic data, including age and gender. This effect was stronger in female (k = 0.02635, p < 0.01) and in patients over 65 y (k = 0.04732, p < 0.01). We also observed a hysteretic effect that when exposed to higher nitrogen dioxide(NO2), counting AF cases recorded by ECG may elevate at lag 0 with a maximum odds ratio(OR) of 1.038 (95% CI 1.014-1.063), on the contrary, O3 reduced the risk of daily visits for AF and its maximum OR was at lag 2, and the OR value was 0.9869 (95% CI 0.9791-0.9948). Other air pollutants such as PM2.5, PM10, and SO2 showed no clear relationship with the recorded AF. CONCLUSION: The associations between air pollution and AF recorded with ECG were preliminarily discovered. Short-term exposure to NO2 was significantly associated with daily hospital visits for AF management.


Subject(s)
Air Pollutants , Air Pollution , Atrial Fibrillation , Humans , Female , Male , Atrial Fibrillation/epidemiology , Atrial Fibrillation/etiology , Cross-Sectional Studies , Cross-Over Studies , Nitrogen Dioxide/adverse effects , Air Pollution/adverse effects , Air Pollutants/adverse effects , Electrocardiography , Hospitals
8.
J Prosthet Dent ; 2023 May 20.
Article in English | MEDLINE | ID: mdl-37217418

ABSTRACT

STATEMENT OF PROBLEM: The nanoparticle jetting (NPJ) technique is a recently developed additive manufacturing method that may have useful dental applications. The manufacturing accuracy and clinical adaptation of zirconia monolithic crowns fabricated with NPJ are unknown. PURPOSE: The purpose of this in vitro study was to compare the dimensional accuracy and clinical adaptation of zirconia crowns fabricated with NPJ and those fabricated with subtractive manufacturing (SM) and digital light processing (DLP). MATERIAL AND METHODS: Five standardized typodont right mandibular first molars were prepared for ceramic complete crowns, and 30 zirconia monolithic crowns were fabricated using SM, DLP, and NPJ (n=10) with a completely digital workflow. The dimensional accuracy at the external, intaglio, and marginal areas was determined by superimposing the scanned data and computer-aided design data of the crowns (n=10). Occlusal, axial, and marginal adaptations were evaluated by using a nondestructive silicone replica and dual scanning method. The 3-dimensional discrepancy was evaluated to determine clinical adaptation. Differences among test groups were analyzed by using a MANOVA and the post hoc least significant difference test for normally distributed data or the Kruskal-Wallis test with Bonferroni correction for nonnormally distributed data (α=.05). RESULTS: Significant differences were found in the dimensional accuracy and clinical adaptation among the groups (P<.001). The NPJ group had a lower overall root mean square (RMS) value for dimensional accuracy (22.9 ±1.4 µm) than the SM (27.3 ±5.0 µm) and DLP (36.4 ±5.9 µm) groups (P<.001). The NPJ group had a lower external RMS value (23.0 ±3.0 µm) than the SM group (28.9 ±5.4 µm) (P<.001) and equivalent marginal and intaglio RMS values than the SM group. The DLP group had larger external (33.3 ±4.3 µm), intaglio (36.1 ±10.7 µm), and marginal (79.4 ±12.9 µm) deviations than the NPJ and SM groups (P<.001). With regard to clinical adaptation, the marginal discrepancy was smaller in the NPJ group (63.9 ±27.3 µm) than in the SM group (70.8 ±27.5 µm) (P<.001). No significant differences were found between the SM and NPJ groups in terms of the occlusal (87.2 ±25.5 and 80.5 ±24.2 µm, respectively) and axial (39.1 ±19.7 and 38.4 ±13.7 µm, respectively) discrepancies. The DLP group had larger occlusal (239.0 ±60.1 µm), axial (84.9 ±29.1 µm), and marginal (140.4 ±84.3 µm) discrepancies than the NPJ and SM groups (P<.001). CONCLUSIONS: Monolithic zirconia crowns fabricated using NPJ have higher dimensional accuracy and clinical adaptation than those fabricated using SM or DLP.

9.
Ecotoxicol Environ Saf ; 256: 114868, 2023 May.
Article in English | MEDLINE | ID: mdl-37018854

ABSTRACT

Inconsistent evidence exists about whether exposure to greenspace benefits childhood asthma. Previous studies have only focused on residential or school greenspace, and no research has combined greenspace exposures at both homes and schools to determine their link with childhood asthma. A population-based cross-sectional study was conducted among 16,605 children during 2019 in Shanghai, China. Self-reported questionnaires were used to collect information on childhood asthma and demographic, socioeconomic and behavioural factors. Environmental data including ambient temperature, particulate matter with aerodynamic diameter less than 1 µm (PM1), enhanced vegetation index (EVI), and normalized difference vegetation index (NDVI) were collected from satellite data. Binomial generalized linear models with a logit link were carried out to evaluate the association between greenspace exposure and children's asthma, as well as the effect modifiers. An interquartile range increment of whole greenspace (NDVI500, NDVI250, EVI500, and EVI250) exposure was associated with a reduced odds ratio of children's asthma (0.88, 95% CI: 0.78, 0.99; 0.89, 95% CI: 0.79, 1.01; 0.87, 95% CI: 0.77, 0.99; and 0.88, 95% CI: 0.78, 0.99, respectively) after controlling potential confounders. Low temperature, low PM1, males, vaginal delivery, suburban/rural area, and without family history of allergy appeared to enhance the greenspace-asthma association. Increased greenspace exposure was associated with a lower risk of childhood asthma, and the association was modified by a range of socio-environmental factors. These findings add to the body of evidence on the benefits of biodiversity and supporting the promotion of urban greenspace to protect children's health.


Subject(s)
Air Pollution , Asthma , Male , Child , Female , Humans , Air Pollution/analysis , Cross-Sectional Studies , Parks, Recreational , China , Environmental Exposure
10.
J Dent Sci ; 18(2): 889-892, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37021269

ABSTRACT

Creating a single complete denture against natural dentition can be challenging. To facilitate the clinical procedure and promote balanced occlusion, we developed a digital workflow of a single complete denture using a multi-functional diagnostic denture (DD). The DD was digitally designed and fabricated using a three-dimensional printing process to create a guide for tooth grinding in opposing dentition and a final impression that allows the jaw relationship and dynamic articulation to be recorded by an intraoral scanner. The definitive complete denture was combined with a milled artificial dentition and titanium-plated denture base. Within three clinical visits, this digital workflow provided better efficiency and easy implementation for a single complete denture.

11.
Environ Pollut ; 327: 121535, 2023 Jun 15.
Article in English | MEDLINE | ID: mdl-37003588

ABSTRACT

Severe air pollution events still occur frequently in Shanghai. In order to predict when Shanghai air quality satisfies the National Ambient Air Quality Standards of China (NAAQSC) and identify potential source areas of criteria air pollutants for the regional joint prevention and control of air pollution, concentration data of PM2.5, PM10, SO2, NO2 and O3 were collected in 2014-2022 at fourteen monitoring sites across Shanghai and surrounding areas. A first - order rate equation with harmonic regression analysis was employed for time series analysis and concentration prediction. Decreasing concentrations were observed widely over all sites except O3 and NO2. It is very likely that the secondary NAAQSC standards for PMx, and SO2 would be met by 2025 and O3 and NO2 would likely become the critical pollutants that determine air quality level after 2025. Regional transport was predominant for PMx and SO2 pollution. A 3D - CWT multisite joint location method was developed to identify their potential source areas at different spatial resolutions. Weighting function correction was assigned via information entropy of endpoint numbers in each cell. A probabilistic parameter WIPSA was proposed to quantify and normalize the probability that grid cells are source areas in order to achieve fourteen - site joint location, and it was comparable and compatible at different spatial resolutions. Potential source areas of PM2.5 and PM10 were similar, including Henan, Shandong, Hebei and Anhui, while origin domains of SO2 mainly covered Henan and Hebei. In all seasons, air pollution that was transported to Shanghai (i.e., PMx and SO2) originated mainly from the North China Plain; the contribution of marine sources was neglectable.


Subject(s)
Air Pollutants , Air Pollution , Air Pollutants/analysis , Nitrogen Dioxide/analysis , China , Air Pollution/analysis , Particulate Matter/analysis , Environmental Monitoring
12.
Front Bioeng Biotechnol ; 11: 1137779, 2023.
Article in English | MEDLINE | ID: mdl-36845197

ABSTRACT

Severe bone atrophy in the maxillary posterior region poses a big challenge to implant restoration. Digitally designed and customized short implants with wing retention provide a safer and minimally invasive implant restoration scheme in such circumstances. Small titanium wings are integrated with the short implant supporting the prosthesis. Using digital designing and processing technology, the wings fixed by titanium screws can be flexibly designed, providing the main fixation. The design of the wings will influence the stress distribution and implant stability. This study analyzes the position, structure, and spread area of the wings fixture scientifically by means of three-dimensional finite element analysis. The design of the wings is set to linear, triangular, and planar styles. Under the simulated vertical and oblique occlusal forces, the implant displacement and stress between the implant and the bone surface are analyzed at different bone heights of 1 mm, 2 mm, and 3 mm. The finite element results show that the planar form can better disperse the stress. By adjusting the cusp slope to reduce the influence of lateral force, short implants with planar wing fixtures can be used safely even if the residual bone height is only 1 mm. The results of the study provide a scientific basis for the clinical application of this new customized implant.

13.
J Funct Biomater ; 14(1)2023 Jan 13.
Article in English | MEDLINE | ID: mdl-36662093

ABSTRACT

Peri-implant lesions, such as peri-implant mucositis and peri-implantitis, are bacterial-derived diseases that happen around dental implants, compromising the long-term stability and esthetics of implant restoration. Here, we report a surface-modification method on zirconia implant abutment using silver linear-beam ion implantation to reduce the bacterial growth around the implant site, thereby decreasing the prevalence of peri-implant lesions. The surface characteristics of zirconia after ion implantation was evaluated using energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and a contact-angle device. The antibacterial properties of implanted zirconia were evaluated using Streptococcus mutans and Porphyromonas gingivalis. The biocompatibility of the material surface was evaluated using human gingival fibroblasts. Our study shows that the zirconia surface was successfully modified with silver nanoparticles by using the ion-implantation method. The surface modification remained stable, and the silver-ion elution was below 1 ppm after one-month of storage. The modified surface can effectively eliminate bacterial growth, while the normal gingiva's cell growth is not interfered with. The results of the study demonstrate that a silver-ion-implanted zirconia surface possesses good antibacterial properties and good biocompatibility. The surface modification using silver-ion implantation is a promising method for future usage.

14.
J Prosthodont ; 32(3): 273-277, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36586420

ABSTRACT

For full-mouth rehabilitation of worn dentition, "diagnostic" interim restorations are required to reestablish the interocclusal relationship. It is important but challenging to transfer the interocclusal relationship and to map the basic form and contour of interim restorations to the final restorations. Alignment of interim restorations and working casts is difficult when using digital workflows because of a lack of consistent hard tissue reference points. The digital workflow presented in this study used a "3-point sectional-cast digital cross-mounting method" to transfer the interocclusal relationship during full-mouth rehabilitation. An intermediate cast was made with three interim restorations: one on an incisor and two on molars. The interocclusal relationship and occlusal morphologies of the diagnostic interim prostheses were transferred and aligned to working casts using the 3-point sectional casts.


Subject(s)
Dentition , Mouth Rehabilitation , Humans , Dental Care , Incisor , Molar
15.
Sci Total Environ ; 857(Pt 3): 159792, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36306842

ABSTRACT

Interest in assessing the effects of exposure to greenspace on human health has been increasing due to rapid urbanization, and rising trends of physical inactivity and air pollution. However, findings on the link between greenspace and child respiratory health, especially asthma, are inconsistent. We investigated the association between greenspace surrounding residential addresses and asthma in children. A city-wide cross-sectional study was conducted, involving 16,605 children aged 3-12 years, in Shanghai, China. Data on asthma symptoms and covariates were collected from validated self-reported questionnaires. Residential greenspace was measured using satellite-derived normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Information on ambient temperature and particulate matter with dynamic diameter <1 µm (PM1) and 2.5 µm (PM2.5) was also collected from satellite data. Logistic regression models were performed to assess the associations of greenspace exposure with childhood asthma as well as the effect modification by covariates. The prevalence of current asthma in children was 4.8 % in this study. An interquartile range increase in mean NDVI from 2016 to 2018 was associated with decreased odds of asthma in 2019 at 500 m, and 250 m resolutions (0.82, 95 % confidence interval (CI): 0.74 to 0.93; and 0.82, 95 % CI: 0.72 to 0.94, respectively) after adjustment for covariates. The greenspace-asthma association was modified by ambient temperature and residential area. Sensitivity analyses using various models and EVI exposure showed the robustness of the results. In conclusion, higher individual-level exposure to greenspace was associated with decreased odds of asthma in children, and the association appeared to be modified by different environmental and socio-demographic factors. These findings provide additional evidence for promoting urban greenness to protect children's health and well-being.


Subject(s)
Air Pollution , Asthma , Humans , Child , Cross-Sectional Studies , Parks, Recreational , China/epidemiology , Particulate Matter/adverse effects , Particulate Matter/analysis , Asthma/epidemiology , Environmental Exposure
16.
Dent Mater J ; 41(6): 896-904, 2022 Nov 30.
Article in English | MEDLINE | ID: mdl-36244735

ABSTRACT

This study aims to evaluate the effects of cold atmospheric plasma (CAP) treatment on the bonding of resin cement to high-translucency zirconia. Zirconia specimens were subjected to different treatments: no treatment (ZrT), 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primer (ZrT-M), alumina particle air-abrasion with/without MDP-containing primer (ZrT-AM/ZrT-A), CAP with/without MDP-containing primer (ZrT-PM/ZrT-P). The surface topography, wettability, and chemical composition were evaluated. The shear bond strength (SBS) was tested before and after thermocycling. CAP did not alter the morphology, increased the wettability, and decreased the carbon/oxygen ratio of zirconia surface. The SBSs of ZrT-PM and ZrT-P were significantly higher than the other groups. After thermocycling, ZrT-A, ZrT-M, ZrT-AM, and ZrT-P showed comparable SBSs, all of which were lower than ZrT-PM. It was concluded that CAP improved the bonding performance of high-translucency zirconia without damaging its surface. The combination of CAP with MDP further enhanced the bond strength and may enable durable bonding.


Subject(s)
Dental Bonding , Plasma Gases , Materials Testing , Surface Properties , Zirconium/chemistry , Resin Cements/chemistry , Ceramics , Shear Strength , Methacrylates/chemistry
17.
PLoS One ; 17(9): e0274204, 2022.
Article in English | MEDLINE | ID: mdl-36074780

ABSTRACT

The recently discovered insecticidal protein Mpp75Aa1.1 from Brevibacillus laterosporus is a member of the ETX_MTX family of beta-pore forming proteins (ß-PFPs) expressed in genetically modified (GM) maize to control western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte). In this manuscript, bioinformatic analysis establishes that although Mpp75Aa1.1 shares varying degrees of similarity to members of the ETX_MTX2 protein family, it is unlikely to have any allergenic, toxic, or otherwise adverse biological effects. The safety of Mpp75Aa1.1 is further supported by a weight of evidence approach including evaluation of the history of safe use (HOSU) of ETX_MTX2 proteins and Breviballus laterosporus. Comparisons between purified Mpp75Aa1.1 protein and a poly-histidine-tagged (His-tagged) variant of the Mpp75Aa1.1 protein demonstrate that both forms of the protein are heat labile at temperatures at or above 55°C, degraded by gastrointestinal proteases within 0.5 min, and have no adverse effects in acute mouse oral toxicity studies at a dose level of 1920 or 2120 mg/kg body weight. These results support the use of His-tagged proteins as suitable surrogates for assessing the safety of their non-tagged parent proteins. Taken together, we report that Mpp75Aa1.1 is the first ETX-MTX2 insecticidal protein from B. laterosporus and displays a similar safety profile as typical Cry proteins from Bacillus thuringiensis.


Subject(s)
Bacillus thuringiensis , Coleoptera , Insecticides , Animals , Bacillus thuringiensis/genetics , Bacillus thuringiensis/metabolism , Bacterial Proteins/metabolism , Brevibacillus , Coleoptera/genetics , Endotoxins/metabolism , Insecticides/pharmacology , Larva/metabolism , Mice , Pest Control, Biological/methods , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Zea mays/genetics , Zea mays/metabolism
18.
Environ Pollut ; 313: 120162, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36113643

ABSTRACT

Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) onto soil threatens terrestrial ecosystem. To locate potential source areas geographically, a total of 139 atmospheric bulk deposition samples were collected during 2012-2019 at eight sites in Shanghai and its surrounding areas. A multisite joint location method was developed for the first time to locate potential source areas of atmospheric PAHs based on an enhanced three dimensional concentration weighted trajectory model. The method considered spatial and temporal variations of atmospheric boundary layer height and homogenized all results over the eight sites via geometric mean. Regional transport was an important contributor of PAH atmospheric deposition while massive local emissions may disturb the identification of potential source areas. Northwesterly winds were associated with elevated deposition fluxes. Potential source areas were identified by the multisite joint location method and included Hebei, Tianjin, Shandong and Jiangsu to the north, and Anhui to the west of Shanghai. PM and SO2 data from the national ground monitoring stations confirmed the identified source areas of deposited PAHs in Shanghai.


Subject(s)
Air Pollutants , Polycyclic Aromatic Hydrocarbons , Air Pollutants/analysis , China , Ecosystem , Environmental Monitoring/methods , Polycyclic Aromatic Hydrocarbons/analysis , Soil
19.
PLoS One ; 17(8): e0272311, 2022.
Article in English | MEDLINE | ID: mdl-35921368

ABSTRACT

Western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte, is an insect pest that poses a significant threat to the productivity of modern agriculture, causing significant economic and crop losses. The development of genetically modified (GM) crops expressing one or more proteins that confer tolerance to specific insect pests, such as WCR, was a historic breakthrough in agricultural biotechnology and continues to serve as an invaluable tool in pest management. Despite this, evolving resistance to existing insect control proteins expressed in current generation GM crops requires continued identification of new proteins with distinct modes of action while retaining targeted insecticidal efficacy. GM crops expressing insecticidal proteins must undergo extensive safety assessments prior to commercialization to ensure that they pose no increased risk to the health of humans or other animals relative to their non-GM conventional counterparts. As part of these safety evaluations, a weight of evidence approach is utilized to assess the safety of the expressed insecticidal proteins to evaluate any potential risk in the context of dietary exposure. This study describes the food and feed safety assessment of Vpb4Da2, a new Bacillus thuringiensis insecticidal protein that confers in planta tolerance to WCR. Vpb4Da2 exhibits structural and functional similarities to other insect control proteins expressed in commercialized GM crops. In addition, the lack of homology to known toxins or allergens, a lack of acute toxicity in mice, inactivation by conditions commonly experienced in the human gut or during cooking/food processing, and the extremely low expected dietary exposure to Vpb4Da2 provide a substantial weight of evidence to demonstrate that the Vpb4Da2 protein poses no indication of a risk to the health of humans or other animals.


Subject(s)
Bacillus thuringiensis , Coleoptera , Insecticides , Animals , Bacillus thuringiensis/genetics , Bacillus thuringiensis/metabolism , Bacillus thuringiensis Toxins , Crops, Agricultural/metabolism , Endotoxins/metabolism , Humans , Insecticide Resistance , Insecticides/pharmacology , Larva , Mice , Pest Control, Biological , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Zea mays/genetics , Zea mays/metabolism
20.
Sci Total Environ ; 839: 156291, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-35644404

ABSTRACT

Global climate change (GCC) is widely accepted as the biggest threat to human health of the 21st century. Children are particularly vulnerable to GCC due to developing organ systems, psychological immaturity, nature of daily activities, and higher level of per-body-unit exposure. There is a rising trend in the disease burden of childhood asthma and allergies in many parts of the world. The associations of CC, air pollution and other environmental exposures with childhood asthma are attracting more research attention, but relatively few studies have focused on CC adaptation measures and childhood asthma. This study aimed to bridge this knowledge gap and conducted the first systematic review on CC adaptation measures and childhood asthma. We searched electronic databases including PubMed, Embase, and Web of Science using a set of MeSH terms and related synonyms, and identified 20 eligible studies included for review. We found that there were a number of adaptation measures proposed for childhood asthma in response to GCC, including vulnerability assessment, improving ventilation and heating, enhancing community education, and developing forecast models and early warning systems. Several randomized controlled trials show that improving ventilation and installing heating in the homes appear to be an effective way to relieve childhood asthma symptoms, especially in winter. However, the effectiveness of most adaptation measures, except for improving ventilation and heating, have not been explored and quantified. Given more extreme weather events (e.g., cold spells and heatwaves) may occur as climate change progresses, this finding may have important implications. Evidently, further research is urgently warranted to evaluate the impacts of CC adaptation measures on childhood asthma. These adaptation measures, if proven to be effective, should be integrated in childhood asthma control and prevention programs as GCC continues.


Subject(s)
Air Pollution , Asthma , Asthma/epidemiology , Child , Climate Change , Environmental Exposure , Humans , Ventilation
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