Influence of 3D printed surface micro-structures on molding performance and dental bonding properties of zirconia.

OBJECTIVES: To investigate the influence of the 3D printed micro-structured surfaces on the bond strength of zirconia to resin cement. METHODS: Zirconia specimens were divided into five groups based on manufacturing technique and surface preparation: (1) milled zirconia (M group); (2) milled zirconia airborne abraded (MA group); (3) printed zirconia (M group); (4) printed zirconia airborne abraded (PA group); and (5) printed zirconia with micro-structured surface (PM group). The surface morphology, cross-sectional morphology, and elemental composition were observed using a scanning electron microscope (SEM). Surface roughness was measured using a laser scanning confocal microscope (SLCM). Shear bond strength (SBS) was measured using a universal testing machine after bonding resin cement (n = 10). The failure modes of the bonded fracture interfaces were observed and counted using a stereomicroscope and a SEM. In addition, boundary dimensional accuracy (n = 10) and micro-structural dimensional accuracy (n = 20) of printed zirconia specimens with micro-structured surfaces were measured using digital calipers and Fiji software. The crystalline phase changes before and after surface treatment were investigated using X-ray diffractometry. Data was analysed using one-way ANOVA and Tukey HSD post-hoc tests (α = 0.05). RESULT: The surface micro-structures of the PM group had regular morphology and no obvious defects. The surface roughness results showed that the PM group had higher Sa (42.21±1.38 um) and Ra (21.25±1.80 um) values than the other four groups (p < 0.001). The SBS test showed that the bond strength of the PM group reached 11.23 ± 0.66 MPa, which was 55.97% (p < 0.001) higher than that of the P group (7.20 ± 1.14 MPa). The boundary dimensional accuracy of the PM group was proficient (diameter: 99.63 ± 0.31%, thickness: 98.05 ± 1.12%), and the actual fabrication dimensions of the hexagonal micro-structures reached 77.45%-80.01% of the original design. The micro-structured surface did not affect the crystalline phase of zirconia. CONCLUSIONS: The current study illustrates that 3D-printed microstructured surfaces effectively improve the bond strength of zirconia to resin cements. CLINICAL SIGNIFICANCE: With the advantage of 3D printing, this study provides a new idea for improving the bonding properties of zirconia.

Adsorption-desorption of Atrazine with 9 Agricultural Soils in China.

In this work, the characteristics and mechanisms for atrazine adsorption-desorption with 9 types of soils were investigated with batch equilibrium studies, elemental analyses, infrared spectroscopy, and UV‒visible spectroscopy. The atrazine sorption data for the 9 soils showed better fits with the Freundlich model than the Langmuir model, except with Red earth in Jiangxi (REJ) The results showed that the adsorption capacity was positively correlated with the organic matter (OM) content and negatively correlated with cation-exchange capacity (CEC) and pH. UV‒visible spectroscopy showed that dissolved organic matter (DOM) in the soil enhanced atrazine adsorption, but the adsorption on different DOM fractions was quite different. In addition, the infrared spectra revealed differences in the functional groups of soils and these functional groups may drive the adsorption process via hydrogen bonding and coordination with the -NH2 groups in atrazine.

Occurrence and transport of novel and legacy poly- and perfluoroalkyl substances in coastal rivers along the Laizhou Bay, northern China.

The pollution profiles of 25 legacy and emerging poly- and perfluoroalkyl substances (PFASs) in the estuaries along the Laizhou Bay, northern China were investigated to better understand the new structure of PFASs under international regulations and to estimate the mass loadings of PFASs in coastal rivers. About 39.87 kg/d of PFASs were discharged into the Laizhou Bay by the Xiaoqing, Mi and Zhimai Rivers. Total PFAS concentrations in the Xiaoqing River decreased notably in recent years, but were still greater than the levels in 2011. Contribution of replacement substances exhibited an increasing trend in recent years. However, the long-chain chemicals were still the larger contributors of PFASs. Perfluoromethoxypropionic acid (PFMPA) was first detected with high concentrations ranging from 165.3 to 586.3 ng/L in the Xiaoqing River. The results of this study provided baseline data for ecological risk assessment, environmental management and corresponding development of pollution treatment technology.

Influence of intraoral scanning duration on data accuracy.

STATEMENT OF PROBLEM: The use of intraoral scanners (IOSs) correlates with clinical outcome and patient satisfaction. While the accuracy of IOSs has been well evaluated, studies on the effect of scanning duration on data accuracy are limited. PURPOSE: The purpose of this in vitro study was to investigate the relationship between different scanning durations and the accuracy of the scanned data. MATERIAL AND METHODS: Two experienced operators used the same intraoral scanner (TRIOS 3; 3Shape A/S) to scan a gypsum cast, but with 5 different scanning durations (30 seconds, 60 seconds, 90 seconds, 120 seconds, and 180 seconds), and the trueness of the scanned data was assessed. Ten scans for each duration group were performed, and all the acquired data were evaluated for precision analysis. In addition, each scanned complete arch cast was divided into anterior and posterior regions at the canine teeth, and the 3-way ANOVA test was used to assess the scanning trueness and precision of the scanned anterior and posterior dental arch. RESULTS: The intraoral scanning results between the 2 operators were highly consistent. The data of the 30-second group showed the lowest trueness and precision (P<.001), whereas no significant difference was found among the other groups (P>.05). The trueness and precision of the scanning data in the posterior region was inferior to that in the anterior region (P<.001). CONCLUSIONS: The duration time of the intraoral scanning (ranging from 60 seconds to 180 seconds) did not influence the accuracy of the acquired data, while excessively rapid scanning adversely affected accuracy.

Uniformly Dispersed Sb-Nanodot Constructed by In Situ Confined Polymerization of Ionic Liquids for High-Performance Potassium-Ion Batteries.

Antimony (Sb) is a potential candidate anode for potassium-ion batteries (PIBs) owing to its high theoretical capacity. However; in the process of potassium alloying reaction; the huge volume expansion (about 407%) leads to pulverization of active substance as well as loss of electrical contact resulting in rapidly declining capacity. Herein; uniformly dispersed Sb-Nanodot in carbon frameworks (Sb-ND@C) were constructed by in situ confined polymerization of ionic liquids. Attributed to the uniformly dispersed Sb-ND and confinement effect of carbon frameworks; as anode for PIBs; Sb-ND@C delivered a superior rate capability (320.1 mA h g-1 at 5 A g-1) and an outstanding cycling stability (486 mA h g-1 after 1000 cycles; achieving 89.8% capacity retention). This work offers a facile route to prepare highly dispersed metal-Nanodot via the in situ polymerization of ionic liquid for high-performance metal-ion batteries.

Analysis of influence of surgical instruments on accuracy of magnetic navigation system for craniofacial surgery robots.

IntroductionIn craniofacial surgery, magnetic navigation systems can effectively extend the doctor's limited visual range, improve their surgical precision, shorten the operation time, and reduce the incidence of surgical complications. Owing to the ease of magnetic navigation, the accuracy of the magnetic navigation system is affected by various equipment in the operating room. Therefore, its large-scale application is lacking because the navigation accuracy requirement can be extremely high during craniofacial surgery. Therefore, the accuracy of magnetic navigation systems is crucial. Various surgical instruments have been evaluated to effectively reduce the interference of magnetic navigation systems with surgical instruments. In craniofacial surgery, magnetic navigation systems can effectively extend the doctor's limited visual range, improve their surgical precision, shorten the operation time, and reduce the incidence of surgical complications. Owing to the ease of magnetic navigation, the accuracy of the magnetic navigation system is affected by various equipment in the operating room. Therefore, its large-scale application is lacking because the navigation accuracy requirement can be extremely high during craniofacial surgery. Therefore, the accuracy of magnetic navigation systems is crucial. Various surgical instruments have been evaluated to effectively reduce the interference of magnetic navigation systems with surgical instruments. In the surgical environment, the use of surgical instruments during mandibular surgery was simulated by selecting several conventional surgical instruments to record errors in the magnetic navigation system. The fluctuation values of the magnetic navigation errors were subsequently estimated and changes in its accuracy measured. MATLAB was used to calculate and analyze the fluctuations of the magnetic navigation errors. As results, the high-frequency electrosurgical system caused the greatest interference with the magnetic navigation system during surgery while powered on, with a maximum fluctuation error value of 1.8120 mm, and the maximum fluctuation error values of the stitch scissors, teeth forceps, and a needle holder were 1.3662, 1.3781, and 0.3912 mm, respectively. The closer the instrument is to the magnetic field generator or navigation target, the greater its impact. In conclusion, stitch scissors, teeth forceps, a needle holder, and the high-frequency electrosurgical system all affect magnetic navigation system accuracy. Therefore, it is necessary to avoid magnetic navigation system use and surgical instrument disturbances during surgery or select surgical instruments that do not interfere with the system. Surgical instruments must be evaluated for electromagnetic interference before they can be used in surgery with a magnetic navigation system.

Dual-Mode Ratiometric Electrochemical and Turn-On Fluorescent Detection of Butyrylcholinesterase Utilizing a Single Probe for the Diagnosis of Alzheimer's Disease.

Biomarkers detection in blood with high accuracy is crucial for the diagnosis and treatment of many diseases. In this study, the proof-of-concept fabrication of a dual-mode sensor based on a single probe (Re-BChE) using a dual-signaling electrochemical ratiometric strategy and a "turn-on" fluorescent method is presented. The probe Re-BChE was synthesized in a single step and demonstrated dual mode response toward butyrylcholinesterase (BChE), a promising biomarker of Alzheimer's disease (AD). Due to the specific hydrolysis reaction, the probe Re-BChE demonstrated a turn-on current response for BChE at -0.28 V, followed by a turn-off current response at -0.18 V, while the fluorescence spectrum demonstrated a turn-on response with an emission wavelength of 600 nm. The developed ratiometric electrochemical sensor and fluorescence detection demonstrated high sensitivity with BChE concentrations with a low detection limit of 0.08 µg mL-1 and 0.05 µg mL-1, respectively. Importantly, the dual-mode sensor presents the following advantages: (1) dual-mode readout can correct the impact of systematic or background error, thereby achieving more accurate results; (2) the responses of dual-mode readout originate from two distinct mechanisms and relatively independent signal transduction, in which there is no interference between two signaling routes. Additionally, compared with the reported single-signal electrochemical assays for BChE, both redox potential signals were detected in the absence of biological interference within a negative potential window. Furthermore, it was discovered that the outcomes of direct dual-mode electrochemical and fluorescence quantifications of the level of BChE in serum were in agreement with those obtained from the use of commercially available assay kits for BChE sensing. This method has the potential to serve as a useful point-of-care tool for the early detection of AD.

Photo-transformation of acetaminophen sensitized by fluoroquinolones in the presence of bromide.

Fluoroquinolones (FQs) are a class of antibiotics with emerging concern. This study investigated the photochemical properties of two representative FQs, i.e., norfloxacin (NORF) and ofloxacin (OFLO). Results showed that both FQs could sensitize the photo-transformation of acetaminophen under UV-A irradiation, during which excited triplet state (3FQ*) was the main active species. In the presence of 3 mM Br‾, the photolysis rate of acetaminophen increased by 56.3% and 113.5% in the solutions with 10 µM NORF and OFLO, respectively. Such an effect was ascribed to the generation of reactive bromine species (RBS), which was verified by 3,5-dimethyl-1H-pyrazole (DMPZ) probing approach. 3FQ* reacts with acetaminophen through one-electron transfer, producing radical intermediates which then couple to each other. Presence of Br‾ did not lead to the formation of brominated products but the same coupling products, which suggests that radical bromine species, rather than free bromine, were responsible for the accelerated acetaminophen transformation. According to the identified reaction products and assisted with the theoretical computation, the transformation pathways of acetaminophen under UV-A irradiation were proposed. The results reported herein suggest that sunlight-driven reactions of FQs and Br‾ may influence the transformation of coexisting pollutants in surface water environments.

The Feasibility of Electromagnetic Navigation Technique to Achieve Preoperative Plan in Mandibular Angle Osteotomy.

BACKGROUND: In contrast to the most commonly used optical navigation system, electromagnetic navigation has huge potential in operations with a narrow field. The purpose of this experiment was to test and confirm whether the electromagnetic navigation method the authors developed for mandibular angle osteotomy (MAO) met clinical requirements. METHODS: Using a dental splint that could be repeatedly mounted on teeth, registration between surgical plan and actual field was performed automatically. RESULTS: Navigation of MAO was first performed on 10 mandibular models. The position precision measured using a coordinate measuring machine was 1.30±0.61 mm. Then, a navigation experiment was performed on 4 patients. Accuracy in actual operation measured by the NDI pointing sensor was 1.89±0.76 mm. Our noninvasive automatic registration process reduced the surgical exposure time and eliminated the bias of the manual selection of registration points. CONCLUSIONS: This preliminary study confirmed the feasibility of the electromagnetic navigation technique in terms of both applicability and accuracy in MAO surgery.

Fe2(MoO4)3 assembled by cross-stacking of porous nanosheets enables a high-performance aluminum-ion battery.

Rechargeable aluminum-ion batteries have attracted increasing attention owing to the advantageous multivalent ion storage mechanism thus high theoretical capacity as well as inherent safety and low cost of using aluminum. However, their development has been largely impeded by the lack of suitable positive electrodes to provide both sufficient energy density and satisfactory rate capability. Here we report a candidate positive electrode based on ternary metal oxides, Fe2(MoO4)3, which was assembled by cross-stacking of porous nanosheets, featuring superior rate performance and cycle stability, and most importantly a well-defined discharge voltage plateau near 1.9 V. Specifically, the positive electrode is able to deliver reversible capacities of 239.3 mA h g-1 at 0.2 A g-1 and 73.4 mA h g-1 at 8.0 A g-1, and retains 126.5 mA h g-1 at 1.0 A g-1 impressively, after 2000 cycles. Furthermore, the aluminum-storage mechanism operating on Al3+ intercalation in this positive electrode is demonstrated for the first time via combined in situ and ex situ characterization studies and density functional theory calculations. This work not only explores potential positive electrodes for aluminum-based batteries but also sheds light on the fundamental charge storage mechanism within the electrode.

Architecting Hierarchical WO3 Agglomerates Assembled With Straight and Parallel Aligned Nanoribbons Enabling High Capacity and Robust Stability of Lithium Storage.

The pursuit of electrochemical energy storage has led to a pressing need on materials with high capacities and energy densities; however, further progress is plagued by the restrictive capacity (372 mAh g-1) of conventional graphite materials. Tungsten trioxide (WO3)-based anodes feature high theoretical capacity (693 mAh g-1), suitable potential, and affordable cost, arousing ever-increasing attention and intense efforts. Nonetheless, developing high-performance WO3 electrodes that accommodate lithium ions remains a daunting challenge on account of sluggish kinetics characteristics and large volume strain. Herein, the well-designed hierarchical WO3 agglomerates assembled with straight and parallel aligned nanoribbons are fabricated and evaluated as an anode of lithium-ion batteries (LIBs), which exhibits an ultra-high capacity and excellent rate capability. At a current density of 1,000 mA g-1, a reversible capacity as high as 522.7 mAh g-1 can be maintained after 800 cycles, corresponding to a high capacity retention of ∼80%, demonstrating an exceptional long-durability cyclic performance. Furthermore, the mechanistic studies on the lithium storage processes of WO3 are probed, providing a foundation for further optimizations and rational designs. These results indicate that the well-designed hierarchical WO3 agglomerates display great potential for applications in the field of high-performance LIBs.

Endocrine Disrupting Compounds from the Source Water of the Huai River (Huainan City), China.

The occurrence and environmental risk of eight endocrine disrupting compounds (EDCs), namely dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), nonyl phenol (NP), bisphenol A (BPA), 17α-ethinylestradiol (EE2) and estrone (E1), from four water sources (Pingshantou, Wanfenggang, Shisi, and Shiyi) of Huai River (Huainan section) were investigated in this study. Except for DMP only found in Pingshantou, all of the selected EDCs existed widely in the source water. DMP, DEP, BBP, DBP, NP, BPA, EE2, and E1 had the ranges of nd (cannot be detected)-130 ng/L, 25-310, 76-1351, 431-1299, 215-627, 23-107, nd-0.174, and 0.143-0.334 ng/L, respectively. Therefore, the studied water sources were associated with notable levels of EDCs, wherein the concentrations of BBP, DBP, and NP were much higher than the other five chemicals. The selected EDCs appeared to be higher in upstream than in downstream (p < 0.05) for each water source, suggesting that EDCs were subjected to a decreasing with water flow. Correlation analysis suggests that DEP-BP-DBP, NP-BPA, and EE2-E1 might have the same sources, respectively; and the source of NP, EE2, and E1 was different from that of BBP, BEP and BBP, and DEP, respectively. It was observed that both the TAS (total ambient severity) and RQ (risk quotient) were less than 1, indicating that EDCs in Huai River (Huainan section) posed little or no thread to the health of local inhabitants and ecological environmental.

Organic-phase synthesis of Li3V2(PO4)3@Carbon nanocrystals and their lithium storage properties.

Decreasing particle size is an efficient strategy for improving the lithium storage properties of Li3V2(PO4)3 (LVP) due to a shorter transport distances of lithium ion and electrons. However, designing and synthesizing LVP nanocrystals (NCs) with sizes smaller than 30 nm remains a challenge. In this work, we developed a facile approach for the fabrication of the monodisperse LVP NCs through a robust high-temperature organic-phase method. The thermodynamics of the synthesis and the possible reaction mechanism were investigated. The results indicate that the organic-phase environment (at 320 °C) may not thermodynamically allow the crystallization of LVP. Nevertheless, oleic acid (OA) and oleylamine (OAm) are essential as capping agents to hinder the agglomeration and growth of the particles. Based on the thermodynamic need, calcination is essential to prepare LVP. The surface electronic conductivity of the LVP NCs was enhanced through a subsequent carbon-coating treatment. The optimum combination of reduction and carbon coating is very favorable for the kinetics of electron transfer and lithium ion diffusion. Therefore, the fabricated LVP@C NCs exhibit superior lithium storage properties with excellent rate capability (84 mA h g-1 at a rate of 20C) and perfect cyclic stability (96.2% capacity retention after 200 cycles at 5C), demonstrating their potential application in high-performance lithium-ion batteries.

[The correlation between stanniocalcin 2 expression and prognosis in laryngeal squamous cell cancer].

OBJECTIVE: In this study, we have detected the expression of STC2 protein in laryngeal cancer and The safe incisal margin by immunohistochemical staining, to evaluate its correlation with clinical features and the prognosis value in laryngeal squamous cell cancer. METHOD: Eighty-one paraffin-embedd specimens of patients who underwent surgery for laryngeal cancer were collected. Clinical data, including date of birth, gender, tumor subsite, tumor stage, RT, and survival status have been recorded. The samples including laryngeal cancer tissues and the safe incisal margin were analyzed for the expression of STC2 protein by immunohistochemical staining. We analyzed the correlations with STC2 expression level and clinical data with software SPSS 18. 0. RESULT: (1)fifty-six cases in 81 cases (69. 1 %) are positive. In 30 cases of the safe incisal margin tissues, STC2 is not expressed, which shows statistically significant differences between the two groups (P<0. 05). (2)Overexpression of STC2 in laryngeal cancer were correlated with the tumor clinical stage and N stage, T stage, tumor site location and histological grade (P<0. 05), but not with genderor age (P> 0. 05). (3)The result showed that the 3-year survival rate is 74. 1%, according to the survival analysis by STC2, STC2 positive group has poorer outcome versus the negative group. (4)The clinical stage displayed the independent value in predicting the tumor prognosis of laryngeal cancer (P<0. 05), not the expression level of STC2. CONCLUSION: Overexpression of STC2 in laryngeal cancer patients is correlated with poor outcome, which means STC2 positive group has poorer prognosis than the STC2 negative group.

A convenient and efficient protocol for isolating high-quality RNA from latex of Hevea brasiliensis (para rubber tree).

Isolating high-quality RNA from latex of H. brasiliensis is a prerequisite to elucidating the molecular mechanisms of rubber biosynthesis and its regulation. Here, an improved protocol was developed for latex collection, transportation, storage, and RNA isolation. Compared with existing ones, our protocol eliminated liquid nitrogen for latex collection and subsequent low-temperature (-70 degrees C) condition for latex storage, making it more convenient and feasible when latex was collected in remote sampling sites, and latex storage and RNA isolation were conducted in poorly-equipped laboratories. Different methods (UV absorbance scans, denaturing gel electrophoresis, autoradiograph monitoring of cDNA synthesis) were used to confirm the high quality of the RNA prepared with this protocol, whose usefulness was further verified by several practical applications, including construction of one high-quality cDNA library, cloning of the full-length cDNAs of 3 novel Hevea sucrose transporter genes, and semi-quantitative RT-PCR analysis of two rubber-biosynthesis essential genes and one sucrose transporter gene.