39 research outputs found
Survival and Clinicopathological Significance of SIRT1 Expression in Cancers: A Meta-Analysis
Background: Silent information regulator 2 homolog 1 (SIRT1) is an evolutionarily conserved enzymes with nicotinamide adenine dinucleotide (NAD)+-dependent deacetylase activity. SIRT1 is involved in a large variety of cellular processes, such as genomic stability, energy metabolism, senescence, gene transcription, and oxidative stress. SIRT1 has long been recognized as both a tumor promoter and tumor suppressor. Its prognostic role in cancers remains controversial.Methods: A meta-analysis of 13,138 subjects in 63 articles from PubMed, EMBASE, and Cochrane Library was performed to evaluate survival and clinicopathological significance of SIRT1 expression in various cancers.Results: The pooled results of meta-analysis showed that elevated expression of SIRT1 implies a poor overall survival (OS) of cancer patients [Hazard Ratio (HR) = 1.566, 95% CI: 1.293–1.895, P < 0.0001], disease free survival (DFS) (HR = 1.631, 95% CI: 1.250–2.130, P = 0.0003), event free survival (EFS) (HR = 2.534, 95% CI: 1.602–4.009, P = 0.0001), and progress-free survival (PFS) (HR = 3.325 95% CI: 2.762–4.003, P < 0.0001). Elevated SIRT1 level was associated with tumor stage [Relative Risk (RR) = 1.299, 95% CI: 1.114–1.514, P = 0.0008], lymph node metastasis (RR = 1.172, 95% CI: 1.010–1.360, P = 0.0363), and distant metastasis (RR = 1.562, 95% CI: 1.022–2.387, P = 0.0392). Meta-regression and subgroup analysis revealed that ethnic background has influence on the role of SIRT1 expression in predicting survival and clinicopathological characteristics of cancers. Overexpression of SIRT1 predicted a worse OS and higher TNM stage and lymphatic metastasis in Asian population especially in China.Conclusion: Our data suggested that elevated expression of SIRT1 predicted a poor OS, DFS, EFS, PFS, but not for recurrence-free survival (RFS) and cancer-specific survival (CCS). SIRT1 overexpression was associated with higher tumor stage, lymph node metastasis, and distant metastasis. SIRT1-mediated molecular events and biological processes could be an underlying mechanism for metastasis and SIRT1 is a therapeutic target for inhibiting metastasis, leading to good prognosis
3D-printed integrative probeheads for magnetic resonance
射频探头前端作为核磁共振设备的核心部件之一,极大程度的决定着系统实验性能的优劣。探头前端通常由射频线圈、射频电路及样品检测管道等部分组成。现有的射频线圈制作技术主要是通过手工或机械手段按照所需的线圈形状进行绕制。但是,当线圈结构较为复杂、不规则,或体积尺寸较小时,常规绕制方法便难以满足结构设计和制造的精度需求,因此造成线圈性能的劣化,增大检测区域的射频场不均匀性,对核磁共振检测产生负面影响。本研究中,利用3D打印熔融沉积制造或光敏树脂选择性固化技术精确加工出一体化磁共振探头前端,使用常温液态金属填充线圈模型管路形成射频线圈,搭建出稳定的一体化磁共振射频探头。利用高精度3D打印和液态金属灌注技术制备出包含有射频线圈和定制化样品管道结构在内的一体化磁共振射频探头前端,克服了传统磁共振三维微型线圈成型困难、与样品腔匹配程度差等问题,提高了探头的信噪比,为定制化的磁共振检测提供了新思路。
该工作由厦门大学电子科学与技术学院陈忠教授、游学秋副研究员和孙惠军高级工程师共同指导完成,博士研究生谢君尧为论文第一作者。厦门大学电子科学与技术学院黄玉清高级工程师、王忻昌副教授、倪祖荣助理教授、硕士研究生张德超,化学化工学院杨朝勇教授、博士研究生李星锐,萨本栋微米纳米科学技术研究院陈宏教授为合作作者。【Abstract】Magnetic resonance (MR) technology has been widely employed in scientific research, clinical diagnosis and geological survey. However, the fabrication of MR radio frequency probeheads still face difficulties in integration, customization and miniaturization. Here, we utilized 3D printing and liquid metal filling techniques to fabricate integrative radio frequency probeheads for MR experiments. The 3D-printed probehead with micrometer precision generally consists of liquid metal coils, customized sample chambers and radio frequency circuit interfaces. We screened different 3D printing materials and optimized the liquid metals by incorporating metal microparticles. The 3D-printed probeheads are capable of performing both routine and nonconventional MR experiments, including in situ electrochemical analysis, in situ reaction monitoring with continues-flow paramagnetic particles and ions separation, and small-sample MR imaging. Due to the flexibility and accuracy of 3D printing techniques, we can accurately obtain complicated coil geometries at the micrometer scale, shortening the fabrication timescale and extending the application scenarios.The work is supported by the National Natural Science Foundation of China (Grants U1632274, 11761141010, U1805261, 11475142, 22073078, and 61801411), and China Postdoctoral Science Foundation (2017M622075).研究工作得到国家自然科学基金、中国博士后科学基金等项目支持
Linearity-Enhanced Dual-Parallel Mach–Zehnder Modulators Based on a Thin-Film Lithium Niobate Platform
In this work, we report a linearity-enhanced dual-parallel Mach–Zehnder modulator (MZM) on a thin-film lithium niobate platform. By setting the optical and electrical splitting ratios at a specific condition, the third-order intermodulation distortions (IMD3) of the child MZMs cancel with each other, whereas the first-order harmonics (FH) reach the maximum. Passive devices instead of thermo-optical switches are used to control the optical power and phase of the child MZMs, which greatly improve the device stability and simplify the operation complexity. To the best of our knowledge, the experimental results show a record-high spurious-free dynamic range on a thin-film lithium niobate platform (110.7 dB·Hz2/3 at 1 GHz). The E-O response decayed about 1.9 dB from 10 MHz to 40 GHz, and the extrapolated E-O 3 dB bandwidth is expected to be 70 GHz. A half-wave voltage of 2.8 V was also achieved. The proposed modulator provides a promising solution for high-bandwidth and low-voltage analog optical links
Advanced Electrode Design for Low-Voltage High-Speed Thin-Film Lithium Niobate Modulators
Exploring a Band-Edge Bragg Grating Modulator on a Hybrid Thin-Film Lithium Niobate Platform
High-performance and compact integrated photonics platform based on silicon rich nitride–lithium niobate on insulator
40 GHz high-efficiency Michelson interferometer modulator on a silicon-rich nitride and thin-film lithium niobate hybrid platform
Shearer parameter optimization and low energy consumption mining based on 3D point cloud characterization of coal wall
Abstract To achieve efficient and low energy consumption mining under different cutting depths of a shearer, a multiparameter coupling optimization method for the shearer based on three‐dimensional (3D) characterization of the coal wall was proposed. First, a seven‐axis absolute articulated arm measuring machine was used to obtain 3D point cloud data of the coal wall, and then the 3D of the coal wall surface was reconstructed by using segmentation, filtering, and stitching processing, thereby obtaining the average thickness of different coal wall areas. Second, through the quadratic rotation regression orthogonal combination experiment, the optimal combination of drum speed, traction speed, and cutting depth was obtained, further obtaining the order of primary and secondary influences, and the regression model. Moreover, a particle swarm optimization algorithm was used to obtain the optimal drum speed and finally, the laboratory and field test experiments were conducted to verify the effectiveness of the proposed optimization algorithm in reducing the cutting energy consumption of shearer. The experiment results show that the given optimization algorithm can adaptively optimize the traction speed and drum speed based on the corresponding cutting depth, which significantly reduces the cutting specific energy consumption of the shearer. Thus, it provided an important technical means for the shearer to achieve low energy consumption and efficient mining