Load cycling enhances bioactivity at the resin–dentin interface

Objectives

The purpose of this study was to evaluate if mechanical loading promotes bioactivity at the resin interface after bonding with three different adhesive approaches.

Methods

Dentin surfaces were subjected to three different treatments: demineralisation by (1) 37% phosphoric acid (PA) followed by application of an etch-and-rinse dentin adhesive Single Bond (SB) (PA + SB), (2) by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA + SB), (3) application of a self-etch dentin adhesive: Clearfil SE Bond (SEB). Bonded interfaces were stored in simulated body fluid during 24 h or 3 w. One half of each tooth was submitted to mechanical loading. Remineralisation of the bonded interfaces was assessed by AFM imaging/nano-indentation, Raman spectroscopy/cluster analysis, dye assisted confocal microscopy evaluation (CLSM) and Masson's trichrome staining.

Results

Loading cycling for 3 w promoted an increase of mechanical properties at the resin–dentin interface. Cluster analysis demonstrated an augmentation of the mineral–matrix ratio in SB-loaded specimens. CLSM showed an absent micropermeability and nanoleakage after loading EDTA + SB and SEB specimens. Trichrome staining reflected a narrow demineralised dentin matrix after loading, almost not observable in EDTA + SB and SEB.

Significance

In vitro mechanical loading promoted mineralization in the resin–dentin interfaces, at 24 h and 3 w of storage.     

Banded structures in collagen vitrigels for corneal injury repair

There is a growing interest in using collagen vitrigels for corneal injury repair. We recently reported the synthesis and thermal denaturation behavior of these gels. In this paper, the banded structure in these vitrified gels is studied by small-angle X-ray scattering (SAXS) one-dimensional (1-D) correlation function analysis and transmission electron microscopy (TEM). Results demonstrate that the collagen vitrigel possess banded structures similar to those of the starting type I collagen, with an average D-spacing of 64 nm (by SAXS) or 57 nm (by TEM). A combination of SAXS 1-D correlation function analyses and TEM show that overlap and gap distances ranged from 30 to 33 nm and from 23 to 25 nm, respectively. Changing the vitrification condition does not impact on the banded structure significantly.     

Pathologic evidence of retinoblastoma seeds supported by field emission scanning electron microscopy and Raman spectroscopy

Purpose:The aim of this study was to examine the pathology of retinoblastoma (RB) seeds with supportive evidence by field emission scanning electron microscopy and Raman spectroscopy.Methods:This study was a laboratory-based observational study. Enucleated eyeballs received in the ocular pathology department of a tertiary eye care center in northeast India were included in the cohort after obtaining written informed consent during the surgery. The study was carried out for 6 years (2015–2020). Most of the eyeballs were Group-E RBs. Standard eyeballs sectioning were done by bread loaf techniques. Gross documentations included RB seeds seen in the smallest calotte done with utmost care. Seeds were documented also in permanent sections. Scanning electron microscopy and Raman spectroscopy were carried out in an index case.Results:Out of the total 59 cases, 35 RB cases had different seedings. The mean age at enucleation was 2.9 years. RB seeds were seen in vitreous (n = 19), subretinal plus vitreous (n = 7), anterior chamber (n = 1), over crystalline lens (n = 3), retinal surface (n = 1), retinal pigment epithelium (RPE; n = 2), subretinal (n = 1), calcified seeds (n = 2). Other characteristics were dusts (n = 7), clouds (n = 11), spheres (n = 4), and unspecified type (n = 13). Histopathological high-risk factors showed significant choroidal (n = 22) and optic nerve (n = 15) involvement. Few cases had extraocular spread. Undifferentiated tumor (n = 24) was seen with higher evidence of necrosis (n = 23). Raman spectra differentiated the seeds from the normal tissue on the basis of lipid and protein content.Conclusion:This study highlights the different types of RB seeds with high-risk factors. The morphology of those seeds showed the difference between vitreous and subretinal seeds under advanced microscopic observations.     

Metasurfaces for Far-Field Radiation Pattern Correction of Antennas under Dielectric Seamed-Radomes

A high-index dielectric radome seam is camouflaged with respect to a low-index dielectric radome panel by tuning the seam with carefully engineered metasurfaces. A transmission-line approach is used to model the metasurface-tuned seam and analytically retrieve the corresponding surface impedance, from which the unit-cell design is then tailored. Full-wave simulations and microwave antenna measurements performed on a proof-of-concept prototype validate the undesired scattering suppression effect in the case of normally and obliquely incident transverse electric and transverse magnetic wave illuminations. Robustness of the proposed solution to fabrication tolerances is also reported. The study presents metasurface-tuning as an easily implementable, frequency adjustable, and polarization insensitive solution to reduce the scattering of dielectric mechanical seams and improve the overall transparency performance of radome structures.     

Ⅲ~Ⅳ期糖尿病肾病不同中医证型的血清蛋白组学研究

目的:探索Ⅲ~Ⅳ期糖尿病肾病(DN)患者血清差异蛋白,同时筛选不同中医证型的血清差异蛋白。方法:收集Ⅲ~Ⅳ期DN患者70例(气阴两虚证19例,脾肾气虚证18例,血瘀证16例,湿热证17例),同时选择健康受试者35例(健康对照组),应用表面加强激光解吸电离-飞行时间-质谱(SELDI-TOF-MS)技术检测各组血清蛋白指纹图谱,并对差异蛋白峰进行对比分析。结果:1) DN组与健康对照组之间共有9个蛋白峰存在显著差异,质荷比(M/Z)分别为2042.57、3291.28、4986.15、5312.69、5564.09、9861.47、10786.53、13392.89、17395.27;2)气阴两虚证与脾肾气虚证之间共有4个蛋白峰存在显著差异,M/Z分别为2994.77、4986.15、7937.25、2758.91;3)气阴两虚证与血瘀证之间共有4个蛋白峰存在显著差异,M/Z分别为4986.15、16982.62、6819.69、9947.36;4)气阴两虚证与湿热证之间共有3个蛋白峰存在显著差异,M/Z分别为4986.15、11741.33、7001.54;5)脾肾气虚证与血瘀证之间共有3个蛋白峰存在显著差异,M/Z分别为3448.22、8063.43、9787.21;6)脾肾气虚证与湿热证之间共有5个蛋白峰存在显著差异,M/Z分别为2144.34、3992.01、8871.35、10568.32、14643.47;7)血瘀证与湿热证之间共有6个蛋白峰存在显著差异,M/Z分别为4233.15、5771.32、5987.18、8496.76、6651.25、13551.94。结论:Ⅲ~Ⅳ期DN组与健康对照组血清蛋白表达存在差异,该差异或可作为相关临床诊断的标志物,对探索DN的发病机制具有重要的参考价值;在不同中医证型之间能够找到差异血清蛋白,可能反映"证"的实质内涵,对今后建立诊断决策模型具有积极意义。     

Multi-Technique Diagnostic Analysis of Plasters and Mortars from the Church of the Annunciation (Tortorici,Sicily)

Plasters and mortars of the Church of the Annunciation (Tortorici, Sicily) were characterized, for the first time, both at the elemental and molecular levels, by means of portable X-ray fluorescence (XRF) and Raman spectroscopy, to achieve information on the “state of health” of the whole structure. The understanding of their degradation mechanisms and the identification of consequent degradation patterns can define the environmental factors responsible for interpreting the potential pathological forms that can impact the general building vulnerability. In this sense, the results obtained in this article provide relevant information to identify and address both the characterization of building materials and the fundamental causes of their deterioration. At the same time, if coupled with the attempt to supply a chronological order of the major restoration interventions carried out on the investigated site, they provide new insights to calibrate the models for building vulnerability studies.