课程文献中心 更多>>

关键词： Bleaching   Ceramics   Surface roughness   Microhardness   Hydrogen peroxide superior   Professional dental prophylaxis   Scanning electron microscopy  

摘要： Background The aim of this study was to investigate the effect of an immune-boosting beverage with Sambucus nigra (SAM), an energy beverage (ENE), an in-office bleaching agent with a novel composition, and a fine-grain professional dental prophylaxis (PDP) paste on the surface roughness (Ra) and microhardness (MH) of CAD/CAM restorative materials over time. Methods Feldspathic ceramic (FC) and polymer infiltrated ceramic network (PICN) specimens were prepared (N = 126). Glazing, polishing, bleaching and immersion in beverages groups were formed. Bleaching gel containing 25% Hydrogen Peroxide Superior was applied to the specimens with a bleaching pen. Ra and MH were measured at five time points of baseline, days 1, 14, 28 and after PDP. Scanning electron microscopy (SEM) images were taken after PDP. Statistics were performed by ANOVA and Bonferroni tests (alpha = 0.05). Results Ra increased over time regardless of material type, polishing method, beverage type and bleaching (p < 0.0001). Glazed and polished FCs caused higher roughness than PICN, SAM and ENE than distilled water, and bleaching than no bleaching (p < 0.0001). For glazed or polished FCs, MH decreased slightly lower at all time points, but for PICN, MH increased until day 28, not changing after PDP. Beverages decreased the MH of ceramics at all time points, but PDP did not lead to a change for PICN (p < 0.0001). The MH decreased more in bleached specimens than in non-bleached specimens up to day 28 (p < 0.0001). According to the SEM images after PDP, the glazed FC had numerous crack marks, pores and detached particles. The polished FC had traces of mechanical polishing. The polymer part of the PICN had voids, but the ceramic part was better preserved. Conclusions Both energy beverages and immune-boosting beverages can increase roughness on FCs compared to PICNs. There was no significant difference between glazing and polishing in terms of lower roughness in FCs. PDP tended to slightly increase the roughn

关键词： Bacterial adhesion   S.Mutans   P.Gingivalis   Dental ceramics   Surface roughness   Glazing  

摘要： Dental restorations fabricated using CAD/CAM require modification/adjustment before cementation. Streptococcus mutans (***) and Porphyromonas gingivalis (***) are prevalent bacterial species that may adhere to these materials and can cause caries, gingivitis/periodontitis. The purpose of this in vitro study was to evaluate the bacterial adherence of *** and *** to five different kinds of modern CAD/CAM restorative materials with different compositions following chairside finishing/polishing and glazing.

关键词： Cotton   CAD   Drought stress   Lignin accumulation   Gene function  

摘要： Cinnamyl alcohol dehydrogenase (CAD) is a crucial enzyme in the final stage of lignin monomer biosynthesis. This study focuses on the CAD gene family within Gossypium hirsutum. Through comprehensive genomic analysis, we identified 29 GhiCAD genes within the Gossypium hirsutum genome using a bioinformatics approach. Phylogenetic analysis revealed that the GhiCAD family can be categorized into four subgroups, which are closest to the evolutionary relationship with Arabidopsis thaliana. There are multiple cis-acting elements on the promoters of GhiCAD genes associated with abiotic stress responses. Some GhiCAD genes demonstrated high expression in various tissues like root, leaf, and sepal, as well as in fiber and ovule at different developmental stages (10 days post anthesis (DPA), 15 DPA, 20 DPA, 25 DPA). The transcript levels of GhiCAD23 were notably elevated when exposed to PEG treatment and drought stress (DS). GhiCAD23 is also co-expressed with many known drought response genes, suggesting its involvement in the plant's reaction to DS. Employing virus-induced gene silencing (VIGS) technology to silence the GhiCAD23 gene, it was found that silencing GhiCAD23 reduced the tolerance of cotton to DS. Under DS, the relative leaf water content, superoxide dismutase (SOD), and catalase (CAT) enzyme activities of the GhiCAD23-silenced cotton plants were decreased by 31.84%, 30.22% and 14.19%, respectively, while malondialdehyde (MDA) was increased by 72.16% compared with the control cohort. Drought promotes the accumulation of lignin, and it was found that silencing the GhiCAD23 reduces lignin accumulation in cotton under DS. The analysis of phenotypic and physiological indicators indicates that GhiCAD23 is vital in cotton's resistance to DS. This investigation provides an important reference for future comprehensive exploration of the GhiCAD23 gene's function in cotton's DS response mechanism.

关键词： Dental marginal adaptation   Trueness   Implant-supported dental prostheses   Additive manufacturing   Laser powder bed fusion   Electron beam melting  

摘要： Additive framework construction for patients with edentulous arches still lacks consolidated guidelines regarding manufacturing and post-processing technologies. To evaluate the impact of post-treatment hot isostatic pressing (HIP) in dental frameworks, an edentulous maxillary replica (EMR) with the all-on-four concept was fabricated, and Ti-6Al-4V dental frameworks were manufactured by milling, Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) technologies. The EMR and frameworks were scanned by the triple-scan technique, and the assessments of vertical and internal gaps, horizontal discrepancies, and trueness were evaluated before and after a HIP cycle (920 degrees C, 100 MPa for 2 h). Laser scanning confocal microscopy analyzed the frameworks surface. Results demonstrate EBM technology displayed a lower vertical gap at baseline and after HIP, and the HIP was beneficial for both DMLS and milling groups, reducing their vertical gap. Adequate lateral and internal fit were found for all groups. The HIP increases both lateral and internal gap for all groups, which is beneficial considering prosthesis assemble. EBM and DMLS presented positive results regarding horizontal discrepancies. Trueness analysis proved that DMLS and EBM technologies can be considered as viable options for dental framework constructions, as no differences were found between the groups on the abutment-framework interface, and that HIP can alter both areas with more complex geometry and areas with a uniform geometry, which can provide benefits for vertical, internal and horizontal measurements. Altogether, the assessment of distortions with 3D scanning technology can help predict the clinical prostheses prognosis, since internal spaces between framework and abutment can be measured.

标准号: GB/T 31126.2-2024

摘要： 本文件描述了采用气相色谱-质谱联用仪（GC-MS）测定纺织品中10种全氟及多氟化合物（见附录A）的方法。 本文件适用于各类纺织品。

标准号: GB/T 44871-2024

摘要： 本文件描述了采用气相色谱-质谱联用仪（GC-MS）测定纺织品中二异氰酸酯类化合物总含量的方法。 本文件适用于各类纺织产品。 注：二异氰酸酯类化合物清单见附录A。

标准号: GB/T 44835-2024

摘要： 本文件描述了采用气相色谱#8259;质谱联用仪(GC-MS)测定纺织品中18 种含氯有机溶剂的方法。 本文件适用于各类纺织产品。

关键词： IVUS   stent implantation   complex CAD   angiography   meta-analysis  

摘要： Background This study is to investigate the efficacy of stent implantation in patients with complex coronary artery disease (CAD) under intravascular ultrasound (IVUS) guidance and non-IVUS guidance. Methods We conducted a systematic search in PubMed, Web of Science, Cochran, and Embase for the articles of IVUS-guided and non-IVUS-guided stent implantation in patients with complex CAD and reported related outcomes. We included major adverse cardiovascular events (MACE), myocardial infarction (MI), cardiac death and other outcome indicators. Relative ratio (RR) and 95% confidence interval (CI) were used for statistical analysis. Results A total of 5,173 subjects were included in 6 randomized control trials. The results showed that the incidence of MACE (RR: 0.63, 95% CI: 0.49-0.82, P < 0.001), cardiac death (RR: 0.61, 95% CI: 0.44-0.85, P = 0.004), target vessel revascularization (TVR) (P = 0.01), target lesion revascularization (TLR) (P = 0.03) and stent thrombosis (ST) (P = 0.002) in the experimental group (IVUS-guidance) was lower than that in the control group (non-IVUS-guidance). However, no statistical difference was observed between the both groups in the incidence of MI (P = 0.13) and all-cause death (P = 0.41). Conclusions Compared with the non-IVUS-guided group, IVUS-guided stent implantation may be more effective for patients with complex CAD.

标准号: GB/T 44945-2024

摘要： 本文件描述了采用化学分析方法测定纺织产品中桑蚕丝和柞蚕丝含量的试验方法。 本文件适用于含有桑蚕丝和柞蚕丝的纺织产品。 注：某些情况下，桑蚕丝无法充分溶解或柞蚕丝过度溶解，则本文件的方法不适用于该样品。

标准号: GB/T 44836-2024

摘要： 本文件描述了纺织品中草甘膦及其盐含量的液相色谱#8259;串联质谱测定方法。 本文件适用于各类纺织产品。