Mediator activates RNA polymerase II (Pol II) function during transcription, but it remains unclear whether Mediator is able to travel with Pol II and regulate Pol II transcription beyond the initiation and early elon...
Mediator activates RNA polymerase II (Pol II) function during transcription, but it remains unclear whether Mediator is able to travel with Pol II and regulate Pol II transcription beyond the initiation and early elongation steps. By using in vitro and in vivo transcription recycling assays, we find that human Mediator 1 (MED1), when phosphorylated at the mammal-specific threonine 1032 by cyclin-dependent kinase 9 (CDK9), dynamically moves along with Pol II throughout the transcribed genes to drive Pol II recycling after the initial round of transcription. Mechanistically, MED31 mediates the recycling of phosphorylated MED1 and Pol II, enhancing mRNA output during the transcription recycling process. Importantly, MED1 phosphorylation increases during prostate cancer progression to the lethal phase, and pharmacological inhibition of CDK9 decreases prostate tumor growth by decreasing MED1 phosphorylation and Pol II recycling. Our results reveal a novel role of MED1 in Pol II transcription and identify phosphorylated MED1 as a targetable driver of dysregulated Pol II recycling in cancer.
目的:分析评价不同材料计算机辅助设计/制作(CAD/CAM)髓超嵌体修复根管治疗后牙体缺损的临床疗效。方法:前瞻性选取海南医学院第二附属医院2019年1月至2020年7月期间收治的120例根管治疗后牙体缺损患者作为研究对象,简单随机分为两组,A组60例,采用Lava Ultimate纳米复合瓷行髓超嵌体修复;B组60例,采用Vita Tri Luxe多层色长石质玻璃陶瓷行髓超嵌体修复。比较分析两组患者修复后6个月和修复后12个月的临床修复疗效(包括修复体边缘密合度、外形、边缘着色、颜色匹配、继发龋、表面质地、食物嵌塞及对颌牙磨耗)及患者对修复的满意度。结果:修复后6个月及修复后12个月,A组与B组的修复体边缘密合度、外形、边缘着色、颜色匹配、继发龋、表面质地及食物嵌塞比率比较,差异无统计学意义(P>0.05),但A组对颌牙磨耗显著优于B组,差异有统计学意义(P<0.05)。A组患者修复满意率(96.67%)明显高于B组(85.00%),差异有统计学意义(χ^(2)=4.092,P=0.043)。结论:Lava Ultimate纳米复合瓷与Vita Tri Luxe多层色长石质玻璃陶瓷用于CAD/CAM髓超嵌体修复根管治疗后牙体缺损,在边缘密合度、外形、边缘着色、颜色匹配、继发龋、表面质地及食物嵌塞方面的临床疗效无显著差异,但Lava Ultimate纳米复合瓷的对颌牙磨耗显著少于Vita Tri Luxe多层色长石质玻璃陶瓷,患者满意率明显更高,更值得推广。
In this paper, we investigated the microstructure evolution and the resulting change in mechanical properties in a Ag@Sn TLP bondline during reflow and thermal aging. A Ag@Sn high-remelting-point bondline was rapidly ...
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In this paper, we investigated the microstructure evolution and the resulting change in mechanical properties in a Ag@Sn TLP bondline during reflow and thermal aging. A Ag@Sn high-remelting-point bondline was rapidly achieved with thermocompression bonding of Ag@Sn powder in only 5 min at 250 A degrees C. After reducing the thickness of the Sn coating on the Ag particles, the main phases in the resulting bondlines changed from Ag/Ag3Sn to Ag/zeta-Ag, increasing the remelting temperatures to 480 A degrees C and above. The voids were effectively controlled by reducing the thickness of the Sn coating, thereby increasing the shear strength by 38%. The large surface area of the Ag/Sn interface, provided by a high density of core-shell Ag@Sn particles, enabled the rapid formation of an interconnection that is entirely composed of Ag and zeta-Ag. After thermal aging, the main phases transformed from Ag/zeta-Ag to Ag/Ag (Sn) solid solution/zeta-Ag, which causes an increase in the remelting temperature of aged interconnections up to 724 A degrees C. The thermal aged samples showed slight decreases in shear strength, but the morphology of the fracture surfaces indicated better ductility.
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