Expression of lncRNA TGFB2-AS1 in the placenta of preeclampsia and its relationship with placental spiral artery recasting / 中华内分泌外科杂志

Objective:To investigate the relationship between the expression level of long non-coding RNA transforming growth factor β2-antisense RNA1 (lncRNA TGFB2-AS1) and placental spiral artery recasting in the placenta of preeclampsia.Methods:A total of 108 pregnant women with severe preeclampsia who were hospitalized in Zaozhuang Maternal and Child Health Hospital and delivered by cesarean section from Oct. 2019 to Jun. 2021 were selected as the research objects, and they were divided into the late-onset preeclampsia group (late-onset severe preeclampsia pregnant women, 56 cases) and early-onset preeclampsia group (early-onset severe preeclampsia pregnant women, 52 cases) ; at the same time, 58 normal pregnant women were selected as the normal pregnancy group. The general data of pregnant women were collected, such as age, systolic blood pressure and diastolic blood pressure. Real-time fluorescent quantitative PCR (qRT-PCR) method was used to detect the expression level of lncRNA TGFB2-AS1 in placental tissues, a scanning electron microscope was used to measure the lumen area and wall thickness of spiral arteries. Pearson correlation analysis method was used to analyze the correlation between the level of lncRNA TGFB2-AS1 in the placenta tissue and the thickness of the spiral artery wall and the area of the lumen of pregnant women with early-onset and late-onset severe preeclampsia.Results:The tube wall thickness [ (119.69±8.31) μm], systolic blood pressure [ (162.86±4.94) mmHg], diastolic blood pressure [ (103.09±2.35) mmHg], and 24-hour urine protein [ (2.17±0.31) g/24 h] in the early preeclampsia group were higher than those in the late preeclampsia group [ (101.04±5.78) μm, (146.95±6.43) mmHg, (92.13±4.74) mmHg, (1.62±0.23) g/24 h] and the normal pregnancy group [ (99.82±5.56) μm, (116.42±9.31) mmHg, (74.25±6.74) mmHg, (0.06±0.02) g/24 h], the placental tissue lncRNA TGFB2-AS1 level (0.62±0.16), lumen area [ (133.74±20.16) μm 2], gestational week of delivery [ (32.15±1.74) weeks], weight of the newborns [ (2.25±0.26) g] were lower than those in the late-onset preeclampsia group [ (0.99±0.21), (185.49±22.75) μm 2, (36.14±1.59) weeks, (3.37±0.32) g] and the normal pregnancy group [ (1.02±0.23), (186.42±23.71) μm 2, (38.19±1.56) weeks, (3.42±0.37) g] ( P<0.05). The systolic blood pressure, diastolic blood pressure, and 24-hour urine protein in the late preeclampsia group were higher than those in the normal pregnancy group, gestational week of delivery was lower than the normal pregnancy group ( P<0.05). Placental tissue lncRNA TGFB2-AS1 of pregnant women with early-onset severe preeclampsia was positively correlated with the lumen area, and negatively correlated with the thickness of the tube wall ( P<0.05). There was no correlation between lncRNA TGFB2-AS1 and the lumen area and wall thickness in the placental tissue of pregnant women with late-onset severe preeclampsia ( P>0.05) . Conclusion:The lncRNA TGFB2-AS1 expression in the placenta tissue of pregnant women with early-onset severe preeclampsia is abnormally low, which may be related to the insufficient recasting of the placental spiral artery.

Effects of recasting in vacuum with argon on the chemical composition of ceramic alloys / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to determine the effect of recasting in vacuum with argon on the chemical composition of cobalt-chromium (Co-Cr), commercially pure titanium (cpTi), palladium-based (Pd-based), and aurum-platinum (Au-
Pt) ceramic alloys.</p><p><b>METHODS</b>Without adding new alloys, Co-Cr, cpTi, Pd-based, and Au-Pt ceramic alloys were recast one to three times under the condition of vacuum compressive casting with argon. Before recasting, four previously cast ceramic alloys were treated with the corresponding method. After polishing, the chemical composition of the four ceramic alloys recasted one to three times were determined by energy-dispersive spectrometry.</p><p><b>RESULTS</b>No significant difference was observed in the chemical composition of the four ceramic alloys recast 1-3 times (P>0.05).</p><p><b>CONCLUSIONS</b>Under the condition of vacuum with argon, the recasting had no obvious influence on the chemical composition of Co-Cr, cpTi, Pd-based, and Au-Pt ceramic alloys.</p>

Evaluation of effect of recasting of nickel‑chromium alloy on its castability using different investment materials: An in vitro study.

Context: Castability has been found to be affected by many aspects of the entire casting system. Very few references in dental literature are available regarding recasting of the base metal alloys. Aims: To evaluate and compare the castability of fresh and reused nickel‑chromium alloy and to evaluate the effect of two brands of investment materials on castability of nickel‑chromium alloy. Subjects and Methods: For the experimental purpose of evaluation of the effect of recasting of nickel‑chromium alloy on its castability, different percentages of new and casted alloy (Nickel‑chromium alloy‑(Wirolloy NB, Type 4 (Ni‑67%; Cr‑25%; Mo‑5%; Si‑1.5%; Mn, Nb, B, C each <1%) and two commercial brands of investment materials namely, Deguvest Impact (Degudent; Dentsply Germany) and Bellavest SH (Degudent; Dentsply Germany) was used to obtain 30 samples. Castability value was obtained using Whitlock’s formula. Student t-test and one way ANOVA using SPSS 20.0 software was done. Results: The results of this study confirm earlier works that demonstrate that there is no significant difference in castability values of new and recast alloys. In addition, it also demonstrated, there was no difference in castability using Deguvest Impact and Bellavest SH investment materials. Conclusions: Within the limitations of the study, it was concluded that there was no significant difference found in castability of different percentage combinations of new and once casted alloy using two investment materials. The addition of new alloy during recasting to maintain the castability of nickel‑chromium alloy may therefore not be required.

Evaluation of flexural bond strength of porcelain to used nickel-chromium alloy in various percentages.

Aim: The aim of this in vitro study was to evaluate the flexural bond strength of porcelain to combinations of used and new nickel-chromium alloy in various proportions. Materials and Methods: Used and new nickel-chromium bonding alloys were combined in various proportions (groups I to V; 10 samples per group) and their flexural bond strengths with porcelain were compared. A three-point loading system was used for the application of load. Load was applied at a constant speed of 0.5 mm/minute and the load required to fracture the porcelain was recorded for each specimen. Statistical Analysis Used: (a) Analysis of variance (ANOVA) and (b) Duncan's multiple range tests. Results: The best bond strength values were seen when 100% new alloy was used. According to the findings of this study, there was no adverse effects noted with up to 75% recast metal, but serious changes were found in the bond strength values when 100% old metal was used. Conclusions: The following conclusions were drawn from the study Fresh nickel-chromium alloy shows the greatest porcelain adherence. There is no significant change in bond strength of ceramic to alloy with up to 75% of used nickel-chromium alloy. At least 25%- of new alloy should be added when recycled nickel-chromium alloy is being used for metal ceramic restorations.

Shear bond strength of porcelain veneer with fresh and recasting Ni-Cr alloy: a comparative in vitro study / Resistência de união ao cisalhamento entre porcelana de recobrimento e liga de Ni-Cr nova e refundida: estudo in vitro comparativo

Introduction: Dental alloys are routinely subjected to multiple casting procedures. Repeated casting of the same alloys may cause loss of trace elements (such as Sn, Si, Mn, etc.) that are essential for the metal ceramic bond. A common practice is to include a proportion of new metal with the previously cast metal that is thought to replenish the lost elements. Objective: The study was done to evaluate the effect of variation in percentage of recasted Ni-Cr alloy used and to compare the effects with the shear bond strength of porcelain to the fresh ingot Ni-Cr alloy. Materials and methods: Uniform patterns were fabricated, invested and casting was done in five different combinations of fresh and recast alloy. A hundred percent fresh alloy; 25% recast with 75% fresh alloy; 50% recast and 50% fresh alloy; 75% recast and 25% fresh alloy; 100% recast alloys. After uniform porcelain application and firing, the specimens were subjected to shear bond test using a universal testing machine. Data were statistically analyzed using Duncans’s multiple comparison test. Results: The results showed that the mean shear bond strength of the 100% fresh alloy was maximum and 100% recast alloy was least among the groups tested. The mean shear bond strength of castings obtained from 100% fresh, 25% recast, and 50% recast alloy were similar to each other and showed statistically significant difference when compared to the 100% recast group. Seventy five percent recast group did not show statistically significant difference with 100% recast alloy. Arch Oral Res. 2011 May/Aug.;7(2)177-82 Rajalbandi SK, Kumar V, Sajjan S. 178 Introduction The Development of “Taggarts” technique of casting by lost wax process into the Dentistry gave an impetus to use alloyed metals as a restoration (1). Most of the dental laboratories commonly use the sprue and button from a previous casting as a part of the melt for the new casting (2, 3). This practice is especially detrimental with ceramometal...

Introdução: Ligas dentárias são rotineiramente submetidas a procedimentos de fundição múltipla. Fundiçõesrepetidas da mesma liga podem causar perda de elementos-traço, tais como Sn, Si e Mn, os quais são essenciaispara a união entre metal e cerâmica. Uma prática comum é a de incluir uma proporção de liga nova com ometal anteriormente fundido visando repor esses elementos perdidos. Objetivo: O presente estudo avaliou oefeito da variação da porcentagem de liga de Ni-Cr refundida na resistência de união ao cisalhamento comporcelana, comparado a liga de Ni-Cr nova. Materials e métodos: Padrões uniformes foram confeccionados,incluídos e fundidos sob cinco diferentes combinações de liga nova e refundida: 100% liga nova; 25% ligarefundida + 75% liga nova; 50% liga refundida + 50% liga nova; 75% liga refundida + 25% liga nova; 100%liga refundida. Após a aplicação uniforme da porcelana e sua posterior cocção, as amostras foram submetidasao teste de cisalhamento utilizando uma máquina universal de ensaios. Os dados foram analisados estatisticamenteatravés do teste de comparações múltiplas de Duncan. Resultados: Os resultados mostraram que amaior resistência de união ao cisalhamento para a liga 100% nova, e a menor resistência para a liga 100%refundida. A resistência de união ao cisalhamento das fundições com 100% de liga nova, 25% e 50% de ligarefundida foi similar e estatisticamente diferente do grupo com 100% de liga refundida. O grupo com 75%de liga refundida não mostrou diferença estatisticamente significante com o grupo de liga 100% refundida.Conclusão: Pode-se concluir que o mínimo de 50% de liga nova para a fundição é uma margem de segurançapara a refundição de ligas de Ni-Cr.