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1.
Mineral Trioxide Aggregate Partial Pulpotomy Versus Formocresol Pulpotomy: A Randomized, Split-Mouth, Controlled Clinical Trial with 24 Months Follow-Up.
Nematollahi, H, Noorollahian, H, Bagherian, A, Yarbakht, M, Nematollahi, S
Pediatric dentistry. 2018;(3):184-189
Abstract
PURPOSE The purpose of this study was to evaluate the clinical and radiographic success rates of mineral trioxide aggregate partial pulpotomy (PP) compared to formocresol pulpotomy (FP) in human primary molars. METHODS In this randomized, controlled, split-mouth, clinical trial, 25 healthy five- to eight-year-olds, with 50 carious primary mandibular second molars lacking clinical and radiographic evidence of pulp pathology, were selected. The selected teeth were randomly assigned into two groups, PP and FP, for vital pulp therapy. Stainless steel crowns were placed as final restorations for both groups. Clinical and radiographic evaluation at six, 12, and 24 months used the following criteria for failure: pain; swelling; sinus tract; mobility; internal or external root resorption; furcation or periapical radiolucency; and widening of periodontal ligament space. The data were analyzed using a binary logistic generalized estimating equation model. RESULTS At the 12-month and 24-month follow-ups, one child and three children, respectively, were lost to follow-up. At the 24-month follow-up, the clinical, radiographic, and overall success rates of PP were 90.9 percent, 90.5 percent, and 81.8 percent versus FP success of 100 percent, 95.2 percent, and 95.2 percent, respectively. CONCLUSION There were no significant differences between clinical, radiographic, and overall success rate of mineral trioxide aggregate partial pulpotomy and formocresol pulpotomy overall 24 months.
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2.
Comparative study of Cu-based bimetallic oxides for Fenton-like degradation of organic pollutants.
Wang, Q, Ma, Y, Xing, S
Chemosphere. 2018;:450-456
Abstract
In order to provide useful information for the rational design of effective Fenton-like catalyst, a series of Cu-based bimetallic oxides were synthesized and their Fenton-like performances for the degradation of Orange II and ciprofloxacin were compared. The structure, chemical oxidation state, surface charge property and redox ability of the catalysts were also investigated by different characterization techniques. Among them, NiCu exhibited the highest adsorption capacity towards Orange II and the highest activity for the production of OH from H2O2 decomposition, which could be attributed to its high surface area and highly positively charged surface. However, FeCu exhibited the highest activity for the degradation of Orange II. The reason might be that FeCu has more unpaired electrons and higher redox ability, thus promoting the activation of adsorbed Orange II through the electron transfer process. By contrast, NiCu exhibited the highest activity for the removal of ciprofloxacin because ciprofloxacin was mainly degraded by OH. Finally, the main degradation intermediates of Orange II and ciprofloxacin were determined by liquid chromatography-mass spectrometry.
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Interaction between Al2O3 and different sizes of GO in aqueous environment.
Liu, X, Xu, X, Sun, J, Duan, S, Sun, Y, Hayat, T, Li, J
Environmental pollution (Barking, Essex : 1987). 2018;(Pt B):1802-1809
Abstract
Although the aggregation of graphene oxide (GO) has been widely researched, the influence of the GO size on the homoaggregation behavior and its interaction with environmental media are still unexplored. In this work, critical coagulation concentration (CCC) values for GO with different sizes, from micro to nanosheet, were measured with NaCl and CaCl2 electrolytes, and the results indicated that GO with the largest size presented the smallest CCC value. Aluminum oxide (Al2O3) was selected as a natural solid particle representative to mimic the interaction between GO and environmental media. Batch experiments were conducted in solution with different pH and ionic strength. Results indicated that the attachment capacity of large GO onto Al2O3 particles was greater than that of small GO. The experimental data were well fitted with Freundlich model. The electrostatic attraction and hydrogen-bonding interaction dominated the interaction process between GO and Al2O3. These findings are important for better understanding in the environmental fate and transport of GO.
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4.
Modeling and evaluation of a high-resolution CMOS detector for cone-beam CT of the extremities.
Cao, Q, Sisniega, A, Brehler, M, Stayman, JW, Yorkston, J, Siewerdsen, JH, Zbijewski, W
Medical physics. 2018;(1):114-130
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Abstract
PURPOSE Quantitative assessment of trabecular bone microarchitecture in extremity cone-beam CT (CBCT) would benefit from the high spatial resolution, low electronic noise, and fast scan time provided by complementary metal-oxide semiconductor (CMOS) x-ray detectors. We investigate the performance of CMOS sensors in extremity CBCT, in particular with respect to potential advantages of thin (<0.7 mm) scintillators offering higher spatial resolution. METHODS A cascaded systems model of a CMOS x-ray detector incorporating the effects of CsI:Tl scintillator thickness was developed. Simulation studies were performed using nominal extremity CBCT acquisition protocols (90 kVp, 0.126 mAs/projection). A range of scintillator thickness (0.35-0.75 mm), pixel size (0.05-0.4 mm), focal spot size (0.05-0.7 mm), magnification (1.1-2.1), and dose (15-40 mGy) was considered. The detectability index was evaluated for both CMOS and a-Si:H flat-panel detector (FPD) configurations for a range of imaging tasks emphasizing spatial frequencies associated with feature size aobj. Experimental validation was performed on a CBCT test bench in the geometry of a compact orthopedic CBCT system (SAD = 43.1 cm, SDD = 56.0 cm, matching that of the Carestream OnSight 3D system). The test-bench studies involved a 0.3 mm focal spot x-ray source and two CMOS detectors (Dalsa Xineos-3030HR, 0.099 mm pixel pitch) - one with the standard CsI:Tl thickness of 0.7 mm (C700) and one with a custom 0.4 mm thick scintillator (C400). Measurements of modulation transfer function (MTF), detective quantum efficiency (DQE), and CBCT scans of a cadaveric knee (15 mGy) were obtained for each detector. RESULTS Optimal detectability for high-frequency tasks (feature size of ~0.06 mm, consistent with the size of trabeculae) was ~4× for the C700 CMOS detector compared to the a-Si:H FPD at nominal system geometry of extremity CBCT. This is due to ~5× lower electronic noise of a CMOS sensor, which enables input quantum-limited imaging at smaller pixel size. Optimal pixel size for high-frequency tasks was <0.1 mm for a CMOS, compared to ~0.14 mm for an a-Si:H FPD. For this fine pixel pitch, detectability of fine features could be improved by using a thinner scintillator to reduce light spread blur. A 22% increase in detectability of 0.06 mm features was found for the C400 configuration compared to C700. An improvement in the frequency at 50% modulation (f50 ) of MTF was measured, increasing from 1.8 lp/mm for C700 to 2.5 lp/mm for C400. The C400 configuration also achieved equivalent or better DQE as C700 for frequencies above ~2 mm-1 . Images of cadaver specimens confirmed improved visualization of trabeculae with the C400 sensor. CONCLUSIONS The small pixel size of CMOS detectors yields improved performance in high-resolution extremity CBCT compared to a-Si:H FPDs, particularly when coupled with a custom 0.4 mm thick scintillator. The results indicate that adoption of a CMOS detector in extremity CBCT can benefit applications in quantitative imaging of trabecular microstructure in humans.
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Nano-graphene oxide incorporated into PMMA resin to prevent microbial adhesion.
Lee, JH, Jo, JK, Kim, DA, Patel, KD, Kim, HW, Lee, HH
Dental materials : official publication of the Academy of Dental Materials. 2018;(4):e63-e72
Abstract
OBJECTIVE Although polymethyl methacrylate (PMMA) is widely used as a dental material, a major challenge of using this substance is its poor antimicrobial (anti-adhesion) effects, which increase oral infections. Here, graphene-oxide nanosheets (nGO) were incorporated into PMMA to introduce sustained antimicrobial-adhesive effects by increasing the hydrophilicity of PMMA. METHODS After characterizing nGO and nGO-incorporated PMMA (up to 2wt%) in terms of morphology and surface characteristics, 3-point flexural strength and hardness were evaluated. The anti-adhesive effects were determined for 4 different microbial species with experimental specimens and the underlying anti-adhesive mechanism was investigated by a non-thermal oxygen plasma treatment. Sustained antimicrobial-adhesive effects were characterized with incubation in artificial saliva for up to 28 days. RESULTS The typical nanosheet morphology was observed for nGO. Incorporating nGO into PMMA roughened its surface and increased its hydrophilicity without compromising flexural strength or surface hardness. An anti-adhesive effect after 1h of exposure to microbial species in artificial saliva was observed in nGO-incorporated specimens, which accelerated with increasing levels of nGO without significant cytotoxicity to oral keratinocytes. Plasma treatment of native PMMA demonstrated that the antimicrobial-adhesive effects of nGO incorporation were at least partially due to increased hydrophilicity, not changes in the surface roughness. A sustained antimicrobial-adhesive property against Candida albicans was observed in 2% nGO for up to 28 days. SIGNIFICANCE The presence of sustained anti-adhesion properties in nGO-incorporated PMMA without loading any antimicrobial drugs suggests the potential usefulness of this compound as a promising antimicrobial dental material for dentures, orthodontic devices and provisional restorative materials.
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Double-Sided Personality: Effects of Arsenic Trioxide on Inflammation.
Zhang, J, Zhang, Y, Wang, W, Li, C, Zhang, Z
Inflammation. 2018;(4):1128-1134
Abstract
In 1992, arsenic trioxide (As2O3, ATO) was demonstrated to be an effective therapeutic agent against acute promyelocytic leukemia (APL), rekindling attention to ATO applications in U.S. Food and Drug Administration clinical trials for the treatment of cancers, such as leukemia, lymphomas, and solid tumors. ATO is a potent chemotherapeutic drug that can also be used to treat other diseases, such as autoimmune diseases, because it affects multiple pathways including apoptosis induction, differentiation stimulation, and proliferation inhibition. As inflammation is a critical component of disease progression, ATO is a feasible treatment option based on its ability to protect against inflammation. However, ATO is also a well-known carcinogen because of its pro-inflammatory effect. This review will focus on the double-sided effects of ATO on inflammation as well as the relevant mechanisms underlying these effects, aiming to provide a rational understanding of how ATO effects the immune system. We especially aim to provide a comprehensive overview of our current knowledge of how ATO influences inflammation.
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Degradation behavior of triclosan by co-exposure to chlorine dioxide and UV irradiation: influencing factors and toxicity changes.
Li, QS, Cai, HW, Li, GX, Chen, GY, Ma, XY, He, WL
Environmental science and pollution research international. 2018;(10):9391-9401
Abstract
This study investigated the transformation of triclosan (TCS) following co-exposure to UV irradiation and ClO2. Special attention was given to understand the influencing of water quality parameters and toxicity changes during the co-exposure process. The results show that the co-exposure process prompted TCS elimination quickly and effectively, with more than 99% of TCS degraded under the experimental conditions. The molar yield ratios of 2,4-dichlorophenol/TCS (2,4-DCP/TCS) were calculated to be 35.81-74.49%; however, the by-product of 2,8-dichlorodibenzop-dioxin (2,8-Cl2DD) was not detected. The TCS degradation was sensitive to ClO2 dosage, pH, H2O2, and natural organic matter (NOM), but not to the carbonate (CO32-) concentration. Neutral and slightly alkaline condition were favorable to TCS elimination. The TCS removal rate increased from 85.33 to 99.75% when the ClO2 concentration increased from 0.25 to 1.5 mg L-1. TCS degradation can be promoted at low NOM level (1, 3, and 5 mg L-1), whereas was inhibited at high NOM concentrations of 7 and 9 mg L-1. While adding H2O2, the degradation rate of TCS increased with increasing H2O2 concentration from 1 to 3 mg L-1; however, too low or overdosed H2O2 (0.5 and 5 mg L-1) hindered TCS degradation. Based on the results of a microtox bioassay, the toxicity did not change following the co-exposure process.
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Mineral trioxide aggregate affects cell viability and induces apoptosis of stem cells from human exfoliated deciduous teeth.
Tsai, CL, Ke, MC, Chen, YH, Kuo, HK, Yu, HJ, Chen, CT, Tseng, YC, Chuang, PC, Wu, PC
BMC pharmacology & toxicology. 2018;(1):21
Abstract
BACKGROUND Mineral trioxide aggregate (MTA) is widely used for pulp-capping procedures in permanent teeth and as a gold standard material in endodontics. The aim of the study was to investigate the effect of MTA on cell viability and apoptosis when MTA is directly in contact with Stem Cells from Human Exfoliated Deciduous Teeth (SHEDs). METHODS MTA was mixed and coated in the bottom of a 24-well plate. SHEDs collected and cultured from normal exfoliated human deciduous teeth (passages 3-4) were seeded on square cover glasses. The glasses with seeded SHEDs were incubated in the plates with or without MTA coating. They were divided into four groups: MTA direct contact, direct control, MTA indirect contact, and indirect control. After 1, 2 and 3 days of culturing, cell morphology was observed and cell viability was assessed by the WST-1 cell cytotoxicity assay. TUNEL assay, immunofluorescent labeling and western blot analysis were used to study the effects of MTA on SHEDs apoptosis. RESULTS MTA impaired cell viability of SHEDs in 1, 2 and 3 days, and the effect of direct contact was more severe. Cell apoptosis with positive Annexin V and TUNEL staining was noted when there was direct contact with MTA. Western blot analysis revealed that Bcl-2 and Bcl-xL decreased after SHEDs were in contact with MTA. CONCLUSIONS This study shows that direct contact with 1 week post-set MTA significantly decreases the viability of SHEDs and induced cell apoptosis. The results suggest that there is a possible cytotoxic effect of pulp tissue when there is direct contact with MTA. Different responses would be expected due to the strong alkaline characteristics of fresh mixed MTA.
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Fabrication of Stabilized Fe⁻Mn Binary Oxide Nanoparticles: Effective Adsorption of 17β-Estradiol and Influencing Factors.
Ning, Q, Yin, Z, Liu, Y, Tan, X, Zeng, G, Jiang, L, Liu, S, Tian, S, Liu, N, Wang, X
International journal of environmental research and public health. 2018;(10)
Abstract
Fe⁻Mn binary oxide nanoparticles (FMBON) were reported to be high performance as adsorbent for pollutants removal from aqueous solution. However, there are still limitations in practice application due to the FMBON tend to aggregate into the micro millimeter level. In order to avoid the agglomeration of nanoparticles, this work synthesized the stabilized Fe⁻Mn binary oxide nanoparticles (CMC-FMBON) by using water-soluble carboxymethyl celluloses (CMC) as the stabilizer. The characteristics of CMC-FMBON and FMBON were measured by using Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Zeta potential. This work systematically investigated the adsorption capacity of CMC-FMBON for 17β-estradiol (E2) and the influences of external environmental factors on E2 removal. The results indicated that CMC-FMBON had much smaller particles, wider dispersion and larger surface area than the FMBON. CMC-FMBON showed better adsorption performance for E2 than FMBON with the maximum adsorption capacity of CMC-FMBON and FMBON were 124.10 and 98.14 mg/g at 298 K, respectively. The experimental data can be well fitted by the model of pseudo-second-order and Langmuir model. The E2 removal by CMC-FMBON was obviously dependent on pH with the maximum adsorption occurring when the pH was acidic. The removal capacity of CMC-FMBON increased when enhancing ionic strength in solution. Background electrolytes promoted slightly E2 adsorption process whereas the presence of humic acid inhibited the E2 removal. π-π interactions, hydrogen bonds, and oxidation might be responsible for E2 removal. This research suggested that the CMC-FMBON has been considered to be a cost-efficient adsorbent for removing E2 from water.
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Deciphering the molecular events during arsenic induced transcription signal cascade activation in cellular milieu.
Madhyastha, H, Madhyastha, R, Nakajima, Y, Maruyama, M
Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. 2018;(1):7-15
Abstract
Anthropogenic sources of arsenic poses and creates unintentional toxico-pathological concerns to humans in many parts of the world. The understanding of toxicity of this metalloid, which shares properties of both metal and non-metal is principally structured on speciation types and holy grail of toxicity prevention. Visible symptoms of arsenic toxicity include nausea, vomiting, diarrhea and abdominal pain. In this review, we focused on the dermal cell stress caused by trivalent arsenic trioxide and pentavalent arsanilic acid. Deciphering the molecular events involved during arsenic toxicity and signaling cascade interaction is key in arsenicosis prevention. FoxO1 and FoxO2 transcription factors, members of the Forkhead/Fox family, play important roles in this aspect. Like Foxo family proteins, ATM/CHK signaling junction also plays important role in DNA nuclear factor guided cellular development. This review will summarize and discuss current knowledge about the interplay of these pathways in arsenic induced dermal pathogenesis.