Tradeoff Control of Multi-exposure Lithography for SU-8 Photochemical Reaction Channel Formation

Qi-Ming Chen,Jin-Yun Zhou,Yi-Ming Hu,Qi Zheng 한국바이오칩학회 2020 BioChip Journal Vol.14 No.4

A method involving multi-exposure with low-power is presented to fabricate an SU-8 mold based on a digital micromirror device (DMD) maskless lithography with an LED source at a wavelength of 405 nm. The SU-8 mold is used for the fabrication of a PDMS concentration gradient generator (CGG). During a one-time exposure, it is easy to over-expose at the top and under-expose at the bottom of a thick SU-8, which then forms a T-shaped structure. This is more obvious for high-absorption coefficients such as 365 nm. We found that by taking advantage of the partially absorbed and partially transmissive characteristics of the 405-nm wavelength, multi-exposure can form an effective photochemical reaction channel in SU-8 and can solve the problem mentioned above. However, excessive exposure will cause the linewidth to increase, therefore, it is necessary to find a tradeoff for the number of multi-exposure times. For a 55-μm thick SU-8, the tradeoff threshold is found to be 25. Three types of SU-8 CGG molds were fabricated at this threshold. The results indicate that the actual profile of the SU-8 mold shows good agreement with the design profile without any T-shaped structures.

Genetic variations in the bitter taste receptor gene TAS2R38 are related to cigarette smoking behavior in Han Chinese smokers

Qi Fei-Yan,Zhu Zhou-Hai,Li Meng,Guan Ying,Peng Qi-Yuan,Lu She-Ming,Liu Zhi-Hua,Wang Ming-Feng,Miao Ming-Ming,Chen Zhang-Yu,Li Xue-Mei,Bai Jie,Yao Jian-Hua 한국유전학회 2022 Genes & Genomics Vol.44 No.11

Background: Smoking behavior is influenced by multiple genes, including the bitter taste gene TAS2R38. It has been reported that the correlation between TAS2R38 and smoking behavior has ethnicity-based differences. However, the TAS2R38 status in Chinese smokers is still unclear. Objective: This study aims to investigate the possible relationship between genetic variations in TAS2R38 (A49P, V262A and I296V) and smoking behaviors in the Han Chinese population. Methods: The haplotype analyses were performed and smoking behavior questionnaire was completed by 1271 individuals. Genetic association analyses for smoking behavior were analyzed using chi-square test. Further, for investigating the molecular mechanism of TAS2R38 variants effect on smoking behavior, we conducted TAS2R38-PAV and TAS2R38-AVI expression plasmids and tested the cellular calcium assay by cigarette smoke compounds stimulus in HEK293. Results: Significant associations of genetic variants within TAS2R38 were identified with smoking behavior. We found a higher PAV/PAV frequency than AVI/AVI in moderate and high nicotine dependence (FTND ≥ 4; X2 = 4.611, 1 df, p = 0.032) and strong cigarette smoke flavor intensity preference (X2 = 4.5383, 1 df, p = 0.033) in participants. Furthermore, in the in vitro cellular calcium assay, total particle matter (TPM), N-formylnornicotine and cotinine, existing in cigarette smoke, activated TAS2R38-PAV but not TAS2R38-AVI-transfected cells. Conclusion: Our data highlights that genetic variations in TAS2R38 are related to smoking behavior, especially nicotine dependence and cigarette smoke flavor intensity preference. Our findings may encourage further consideration of the taste process to identify individuals susceptible to nicotine dependence, particularly Han Chinese smokers.

Managerial Financial Education and the Valuation Effects of Seasoned Equity Offerings: Evidence from Taiwan

Xuan-Qi Su,Ching-Yen Chen,Chin-Ming Chen,Mei-Shih Chen 한국증권학회 2019 Asia-Pacific Journal of Financial Studies Vol.48 No.6

This paper tests how managerial financial education explains the valuation effects of seasoned equity offerings (SEOs). Using a sample of Taiwanese listed firms during 2007–2018, our results show that investors react more negatively to SEO announcements by firms with more financially educated managers (MFEMs). Such a negative effect is more pronounced for firms with a higher information asymmetry and more earnings management. Further evidence indicates that SEO firms with MFEMs are substantially overvalued and thus experience a significantly long-run post-SEO underperformance. MFEMs are also found to reduce their ownership prior to SEOs. Our overall results support the opportunism-based information advantage hypothesis.

LncRNA TMPO-AS1 promotes esophageal squamous cell carcinoma progression by forming biomolecular condensates with FUS and p300 to regulate TMPO transcription

Luo Xiao-Jing,He Ming-Ming,Liu Jia,Zheng Jia-Bo,Wu Qi-Nian,Chen Yan-Xing,Meng Qi,Luo Kong-Jia,Chen Dong-Liang,Xu Rui-Hua,Zeng Zhao-Lei,Liu Ze-Xian,Luo Hui-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Esophageal squamous cell carcinoma (ESCC) is one of the most life- and health-threatening malignant diseases worldwide, especially in China. Long noncoding RNAs (lncRNAs) have emerged as important regulators of tumorigenesis and tumor progression. However, the roles and mechanisms of lncRNAs in ESCC require further exploration. Here, in combination with a small interfering RNA (siRNA) library targeting specific lncRNAs, we performed MTS and Transwell assays to screen functional lncRNAs that were overexpressed in ESCC. TMPO-AS1 expression was significantly upregulated in ESCC tumor samples, with higher TMPOAS1 expression positively correlated with shorter overall survival times. In vitro and in vivo functional experiments revealed that TMPO-AS1 promotes the proliferation and metastasis of ESCC cells. Mechanistically, TMPO-AS1 bound to fused in sarcoma (FUS) and recruited p300 to the TMPO promoter, forming biomolecular condensates in situ to activate TMPO transcription in cis by increasing the acetylation of histone H3 lysine 27 (H3K27ac). Targeting TMPO-AS1 led to impaired ESCC tumor growth in a patient-derived xenograft (PDX) model. We found that TMPO-AS1 is required for cell proliferation and metastasis in ESCC by promoting the expression of TMPO, and both TMPO-AS1 and TMPO might be potential biomarkers and therapeutic targets in ESCC.

Evaluate Dry Deposition Velocity of the Nitrogen Oxides Using Noah-MP Physics Ensemble Simulations for the Dinghushan Forest, Southern China

Qi Zhang,Ming Chang,Shengzhen Zhou,Weihua Chen,Xuemei Wang,Wenhui Liao,Jianing Dai,ZhiYong Wu 한국기상학회 2017 Asia-Pacific Journal of Atmospheric Sciences Vol.53 No.4

There has been a rapid growth of reactive nitrogen (Nr) deposition over the world in the past decades. The Pearl River Delta region is one of the areas with high loading of nitrogen deposition. But there are still large uncertainties in the study of dry deposition because of its complex processes of physical chemistry and vegetation physiology. At present, the forest canopy parameterization scheme used in WRF-Chem model is a single-layer “big leaf” model, and the simulation of radiation transmission and energy balance in forest canopy is not detailed and accurate. Noah-MP land surface model (Noah-MP) is based on the Noah land surface model (Noah LSM) and has multiple parametric options to simulate the energy, momentum, and material interactions of the vegetation-soil-atmosphere system. Therefore, to investigate the improvement of the simulation results of WRF-Chem on the nitrogen deposition in forest area after coupled with Noah-MP model and to reduce the influence of meteorological simulation biases on the dry deposition velocity simulation, a dry deposition single-point model coupled by Noah- MP and the WRF-Chem dry deposition module (WDDM) was used to simulate the deposition velocity (Vd). The model was driven by the micro-meteorological observation of the Dinghushan Forest Ecosystem Location Station. And a series of numerical experiments were carried out to identify the key processes influencing the calculation of dry deposition velocity, and the effects of various surface physical and plant physiological processes on dry deposition were discussed. The model captured the observed Vd well, but still underestimated the Vd. The self-defect of Wesely scheme applied by WDDM, and the inaccuracy of built-in parameters in WDDM and input data for Noah-MP (e.g. LAI) were the key factors that cause the underestimation of Vd. Therefore, future work is needed to improve model mechanisms and parameterization.

Poly (dimethyl siloxane)/poly (2-hydroxyethyl methacrylate) interpenetrating polymer network beads as potential capsules for biomedical use

Qi Tang,Jun-Rong Yu,Lei Chen,Jing Zhu,Zu-Ming Hu 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Silicone hydrogels represent a series of novel materials designed for extensive applications especially in the biomedical field. In the current work, a method to obtain poly (dimethyl siloxane)/poly (2-hydroxyethyl methacrylate) (PDMS/PHEMA) interpenetrating polymer network (IPN) beads was developed. With further optimization, up to 43% PHEMA was incorporated into size controllable PDMS microspheres,offers an improved hydrophilicity and thus a reduced protein adsorption for long-term use. Furthermore, we found the PDMS/PHEMA IPN beads possess a hollow capsule-like structure, proposing their application as novel drug delivery vehicles. In vitro release studies have demonstrated two release patterns of these IPN beads for water-soluble drugs just by modulating the drug concentration, suggesting their possible applications in different delivery systems.

Preparation and properties of morphology controlled poly(2-hydroxyethyl methacrylate)/poly(N-vinyl pyrrolidone) double networks for biomedical use

Qi Tang,Jun-Rong Yu,Lei Chen,Jing Zhu,Zu-Ming Hu 한국물리학회 2010 Current Applied Physics Vol.10 No.3

Poly(2-hydroxyethyl methacrylate)/poly(N-vinyl pyrrolidone) (PHEMA/PVP) double networks (DN) were prepared using a sequential method by incorporating a second network of crosslinked PVP into PHEMA. We found that the distributions of the two networks can be regulated just by modulating the morphology of the first network, thus giving expected high water content of these gels. Fourier transform infrared (FTIR) spectroscopy and scanning electronic microscopy (SEM) were used to confirm the structure of the DN. The incorporation of more hydrophilic PVP enhanced swelling ability of these gels. Because of improved hydrophilicity, the PHEMA/PVP DN exhibited higher loading capability for water-soluble substance than that of pure PHEMA, while showed a slower release rate than corresponding HEMA/NVP copolymer hydrogel. It is suggested that the DN gels are potential biomaterials for wound dressing, medical implants and other drug delivery systems.

Multi-objective Optimization Strategy for Continuous Drilling Parameters of Superalloys

Qi Wang,Xi Chen,Qinglong An,Ming Chen,Hun Guo,Yafeng He 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.4

There are a large number of holes to be machined on aeroengine components such as blisks, casings, etc. In order to ensure position accuracy, these holes usually need to be drilled continuously in one process. To ensure the machining quality of holes, either replacing the cutting tools in advance leads to an increase in manufacturing costs, or adjusting process parameters leads to a decrease in production efficiency, which is difficult to meet the requirements of efficient and low-cost manufacturing. In response to this issue, this paper proposes a multi-objective optimization strategy for the process parameters of porous continuous drilling of superalloys alloys. A unified mathematical model for multi-objective optimization of drilling parameters has been established, and a tool life prediction model based on machining parameters and a machining process energy consumption model have been established as objective functions. The proposed optimization strategy can select different optimization strategies for different optimization objectives, including: maximum tool life, minimum machining energy consumption, and multi-objective drilling parameter optimization. Finally, experimental verification was conducted on the proposed strategy, and the results showed that the proposed optimization strategy can significantly reduce drilling processing energy consumption and increase the service life of drilling tools.

Influence of a Flexible Retaining Wall on Performance of an Adjacent Deep Excavation

Qi-Run Yang,Ming-Guang Li,Jin-Jian Chen 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

In urban areas with scarce land resources, many deep excavations are performed adjacent to flexible retaining walls. This study investigated the influence of a flexible retaining wall on the performance of an adjacent deep excavation through numerical modeling. The numerical method incorporating the hardening soil small-strain model and input parameters were primarily validated using a well-documented case. Hypothetical models with different spacings between the deep excavation and existing flexible retaining wall were established to study the deformation behavior of diaphragm walls and characteristics of lateral earth pressure. Parametric studies were carried out to investigated the influence of the excavation width, wall depth, and bending rigidity of retaining walls on the performance of the excavation. Finally, the mechanisms of the flexible retaining wall to influence the mobilization of the arching effect in confined soil were discussed. Results show that the adjacent flexible retaining wall aggravates maximum wall deformation and leads to the inclination of the excavation. The impact is mainly attributed to the redistribution of lateral earth pressure resulted from the mobilization of the arching effect. However, the influence of the flexible retaining wall on the magnitude of the resultant force of lateral earth pressure is insignificant. Both qualitative analysis and numerical results prove that the general shape of the major principal stress trace is a curve convex to stabilized soil when the arching effect is generated.

A heat shock protein 70 protects the green peach aphid (Myzus persicae) against high-temperature stress

Chen Nan,Tan Jia-Yu,Wang Ying,Qi Ming-Hui,Peng Jiang-Nan,Chen De-Xin,Liu Su,Li Mao-Ye 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Heat shock proteins (HSPs) are encoded by Hsp genes and are important in insect tolerance to heat stress. The green peach aphid, Myzus persicae, is an important agricultural pest. The functions of Hsp genes in the thermal tolerance of M. persicae are unknown. This study identified an Hsp70 gene (MpHsp70a) and analyzed its role in protection against high-temperature stress. MpHsp70a encoded a protein consisting of 659 amino acid residues. The protein had three signature motifs of the HSP70 family and was predicted to be localized in the cytoplasm. The highest expression level of MpHsp70a was in adults, and differences in the mRNA levels between apterous and alate adults were not significant. Exposure to high temperatures (30, 35 and 40 ◦ C) for one hour and treatment with 40 ◦ C for different times (0.5, 1 and 2 h) all resulted in a greatly elevated expression level of MpHsp70a, suggesting that the gene is heat-inducible. The transcriptional level of MpHsp70a was suppressed by injection with double-stranded RNA (dsRNA), and knockdown of MpHsp70a significantly increased the suscep tibility of apterous adults to 40 ◦ C. These results indicate that MpHsp70a is required for tolerance to hightemperature stress in M. persicae. Our findings highlight the molecular mechanism underlying Hsp70-mediated thermal adaptation in M. persicae.