Effects of Quenching Methods and Aging Processes on the Crushing Properties and Microstructure of Al–Zn–Mg Alloy Thin-Walled Square Extrusions

Hui Guo,Jin Zhang,Cheng Wang,Yun‑lai Deng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the effects of different (online quenching and offline quenching) quenching methods and aging processes (T6and T73) on the crashworthiness and microstructural evolution of three Al–Zn–Mg alloys (G1–G3) were studied by conductingtensile test and axial compression tests at room temperature, combined with optical metallography, electron back scattereddiffraction, and transmission electron microscopy microstructural observations. The obtained results revealed that thecrushing properties of three different Al–Zn–Mg alloys subjected to different quenching methods and aging processes weresignificantly different. Their crushing energy absorption of are ranked as follows: G1 > G3 > G2. The highest total energyabsorption gap (between T6 and T73) is the G1 alloy, and the lowest one is the G3 alloy. The largest total energy absorptiongap between the two quenching methods is the G3 alloy, and the smallest one is the G1 alloy. The G2 alloy with the largesttotal amount of Zn + Mg has the highest number density of matrix precipitates, the largest precipitate gap (between T6 andT73) and the smallest precipitate gap between the two quenching methods. The G3 alloy with the largest Zn/Mg ratio hasthe smallest number density of matrix precipitates, the minimum precipitation gap (between T6 and T73) and the maximumprecipitation gap between the two quenching methods. The G1 alloy with the lowest Zn/Mg ratio has the smallest size ofgrain boundary precipitates and PFZ width, while their largest values are obtained for the G3 alloy with the maximum Zn/Mg ratio. As a crushing resistant structural material, the crushing properties is improved without reducing the strength. Theratio of Zn/Mg should be controlled within the range of 4.57–6.15, while the total amount of Zn + Mg should be controlledwithin the range of 6.18–7.01.

MUC16 facilitates cervical cancer progression via JAK2/STAT3 phosphorylation‑mediated cyclooxygenase‑2 expression

Hui Shen,Meng Guo,Lu Wang,Xinyue Cui 한국유전학회 2020 Genes & Genomics Vol.42 No.2

Objectives MUC16 (mucin 16, also known as CA-125, cancer antigen 125, carcinoma antigen 125, or carbohydrate antigen 125) has been predicted as tumor biomarker for therapy. We determined to investigate effects and regulatory mechanism of MUC16 on cervical tumorigenesis. Methods Expression levels of MUC16 in cervical cancer cell lines was analyzed via qRT-PCR (quantitative real-time polymerase chain reaction). Knockdown of MUC16 was conducted via shRNA (Short hairpin RNA) transfection. MTT and colony formation assays were used to investigate effect of MUC16 on cell proliferation. Wound healing assay was utilized to detect migration and transwell assay to detect invasion. The underlying mechanism was demonstrated via western blot analysis. Results MUC16 was elevated in cervical cancer cell lines. MUC16 knockdown inhibited cell proliferation, invasion and migration. Gain- and loss-of functional assays revealed that over-expression of MUC16 activated Janus Kinase 2 (JAK2)/ signal transducer and activator of transcription 3 (STAT3) via phosphorylation, thus facilitating cyclooxygenase-2 (COX-2) expression, while knockdown of MUC16 demonstrated the reverse effect on JAK2/STAT3 activation and COX-2 expression. Moreover, inhibition of JAK2/STAT3 attenuated the regulation of MUC16 on COX-2. Conclusions MUC16 enhanced proliferation and invasion of cervical cancer cells via JAK2/STAT3 phosphorylation-mediated cyclooxygenase-2 expression, suggesting the potential therapeutic target ability of MUC16 to treat cervical cancer.

Production of a Recombinant Laccase from Pichia pastoris and Biodegradation of Chlorpyrifos in a Laccase/Vanillin System

( Hui fang Xie ),( Qi Li ),( Min Min Wang ),( Lin Guo Zhao ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was 60℃, but it was not stable at high temperature. The enzyme could remain stable at 30℃ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system (kobs = 0.151) than that in the buffer solution (kobs = 0.028).

Optimizing Imaging Quality and Radiation Dose by the Age-Dependent Setting of Tube Voltage in Pediatric Chest Digital Radiography

Hui Guo,Wen-Ya Liu,Xiao-Ye He,Xiao-Shan Zhou,Qun-Li Zeng,Bai-Yan Li 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.1

Objective: The quality and radiation dose of different tube voltage sets for chest digital radiography (DR) were compared in a series of pediatric age groups. Materials and Methods: Forty-five hundred children aged 0-14 years (yr) were randomly divided into four groups according to the tube voltage protocols for chest DR: lower kilovoltage potential (kVp) (A), intermediate kVp (B), and higher kVp (C)groups, and the fixed high kVp group (controls). The results were analyzed among five different age groups (0-1 yr, 1-3 yr, 3-7 yr, 7-11 yr and 11-14 yr). The dose area product (DAP) and visual grading analysis score (VGAS) were determined and compared by using one-way analysis of variance. Results: The mean DAP of protocol C was significantly lower as compared with protocols A, B and controls (p < 0.05). DAP was higher in protocol A than the controls (p <0.001), but it was not statistically significantly different between B and the controls (p = 0.976). Mean VGAS was lower in the controls than all three protocols (p < 0.001 for all). Mean VGAS did not differ between protocols A and B (p = 0.334), but was lower in protocol C than A (p = 0.008) and B (p = 0.049). Conclusion: Protocol C (higher kVp) may help optimize the trade-off between radiation dose and image quality, and it may be acceptable for use in a pediatric age group from these results.

Characterization and Expression Profile Analysis of a New cDNA Encoding Taxadiene Synthase from Taxus media

Guo Yin Kai,Ling Xia Zhao,Lei Zhang,Zhu Gang Li,Bin Hui Guo,Dong Li Zhao,Xiao Fen Sun,Zhi Qi Miao,Ke Xuan Tang 한국생활환경학회 2005 BMB Reports Vol.38 No.6

Chiral recognition of mandelic acid on quartz crystal microbalance by vapor diffused molecular assembly method.

Guo, Hui-Shi,Kim, Jong-Min,Chang, Sang-Mok,Kim, Woo-Sik American Scientific Publishers 2009 Journal of nanoscience and nanotechnology Vol.9 No.5

<P>This study presents a new approach for the highly selective recognition of chiral L/D-mandelic acid (MA) using a quartz crystal microbalance (QCM) with L-phenylalanine (L-Phe) as the selector. The immobilization of L-Phe on the gold surface of the QCM sensor was performed using a four steps layer-by-layer assembling procedure. The modification of the gold surface of the QCM sensor after each modification step was verified by the cyclic voltammetry, contact angle, FTIR, and QCM detection. The chiral recognition ability of L- and D-MA on the chiral surface was checked by sensing using the vapor diffused molecular assembly (VDMA) method with the QCM. The chiral discrimination factor between L- and D-MA, aplha(L-MA/D-MA), was found to be about 9. The L-Phe-modified QCM gold sensor also showed good stability and reusability. The high chiral discrimination ability of the modified surface might be the result of the different hydrogen bonding force between L- or D-MA and L-Phe.</P>

ACOS5 is Required for Primexine Formation and Exine Pattern Formation During Microsporogenesis in Arabidopsis

Hui-hui Xie,Lin Chen,Fa-qing Xu,Wan-sheng Guo,Shui Wang,Zhong-Nan Yang,Sen Zhang 한국식물학회 2017 Journal of Plant Biology Vol.60 No.4

Pollen exine, mainly composed of sporopollenin,plays important roles during microspore development. It hasbeen reported that Acyl-CoA Synthetase5 (ACOS5) is requiredfor sporopollenin biosynthesis in Arabidopsis. Here we showthat ACOS5 is essential for primexine formation duringArabidopsis microspore development. Through genetic screen,we identified a point mutation of ACOS5 allele, acos5-2,showing abnormal microspore development. Its microsporeswere degenerated and aborted after released from the tetrads. Transmission electron microscopy showed that primexineformation was reduced in acos5-2 mutant as compared tothat of the wild-type. Consequently, sporopollenin wasaggregated and randomly deposited on the microspores. Insitu hybridization indicated that the key regulators of tapetumdevelopment, DYT1 and TDF1, are required for the expressionof ACOS5 in tapetum. Furthermore, the GUS reporter showedthat the 593-bp promoter sequence was sufficient for theexpression of ACOS5 in the anther. Our data provide evidencethat ACOS5 is required for primexine formation andsporopollenin deposition during microspore development.

Simultaneous Single-Position Lateral Lumbar Interbody Fusion Surgery and Unilateral Percutaneous Pedicle Screw Fixation for Spondylolisthesis

Hui Lv,Yu Sheng Yang,Jian Hong Zhou,Yuan Guo,Hui Chen,Fei Luo,Jian Zhong Xu,Zhong Rong Zhang,Ze Hua Zhang 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: To evaluate the clinical and radiological efficacy of a combine of lateral single screw-rod and unilateral percutaneous pedicle screw fixation (LSUP) for lateral lumbar interbody fusion (LLIF) in the treatment of spondylolisthesis. Methods: Sixty-two consecutive patients with lumbar spondylolisthesis who underwent minimally invasive (MIS)-TLIF with bilateral pedicle screw (BPS) or LLIF-LSUP were retrospectively studied. Segmental lordosis angle (SLA), lumbar lordosis angle (LLA), disc height (DH), slipping percentage, the cross-sectional areas (CSA) of the thecal sac, screw placement accuracy, fusion rate and foraminal height (FH) were used to evaluate radiographic changes postoperatively. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy. Results: Patients who underwent LLIF-LSUP showed shorter operating time, less length of hospital stay and lower blood loss than MIS-TLIF. No statistical difference was found between the 2 groups in screw placement accuracy, overall complications, VAS, and ODI. Compared with MIS-TLIF-BPS, LLIF-LSUP had a significant improvement in sagittal parameters including DH, FH, LLA, and SLA. The CSA of MIS-TLIF-BPS was significantly increased than that of LLIF-LSUP. The fusion rate of LLIF-LSUP was significantly higher than that of MIS-TLIF-BPS at the follow-up of 3 months postoperatively, but there was no statistical difference between the 2 groups at the follow-up of 6 months, 9 months, and 12 months. Conclusion: The overall clinical outcomes and complications of LLIF-LSUP were comparable to that of MIS-TLIF-BPS in this series. Compared with MIS-TLIF-BPS, LLIF-LSUP for lumbar spondylolisthesis represents a significantly shorter operating time, hospital stay and lower blood loss, and demonstrates better radiological outcomes to maintain lumbar lordosis, and reveal an overwhelming superiority in the early fusion rate.

Highly Chemo- and Regioselective Reaction of Hydroxybenzenes in Acidic Ionic Liquid

Hui Guo,Yu Wei Zhuang,Jian Cao,Guo Bao Zhang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

Highly chemo- and regioselective reaction of hydroxybenzenes with α,β-unsaturated compounds in acidic ionic liquid l-butyl-3-methylimidazolium hydrogen sulphate ([BMIM]HSO4) was reported for the first time. A series of oxa-Michael adducts and Friedel-Crafts alkylated products were synthesized with good yields. The acidic ionic liquid could be easily recycled for at least 5 times with only minor loss in activity.

Prevalence, Risk Factors, and Psychological Effects of Primary Nocturnal Enuresis in Chinese Young Adults

Hui Jie Hu,Zhen Wei Zhang,Yu Liang,Yan Yan Luo,Qi Feng Dou,Cui Ping Song,Hui Min Zhang,Ying Zhao,Guang Run Tian,Ke Zhang,Qiu Fang Mao,Jing Gui Song,Soren Rittig,Jian Guo Wen 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.1

Purpose: This study aimed to investigate the prevalence, risk factors, and effects of primary nocturnal enuresis (PNE) on physical and mental health in young adults in mainland China. Methods: An anonymous questionnaire was used to collect information including the sociodemographic characteristics, history of PNE, family history, daytime voiding symptoms, Pittsburgh Sleep Quality Index (PSQI) scores, Self-Esteem Scale (SES), and Self-Rating Depression Scale (SDS). A total of 22,500 university students from 23 provinces and 368 cities in mainland China were included. Results: In total, 21,082 questionnaires were collected, and 20,345 of them qualified for statistical analysis. The PNE prevalence was 1.17%, and the distribution of monosymptomatic nocturnal enuresis (MNE) and nonmonosymptomatic nocturnal enuresis (NMNE) was 66.1% and 33.9%, respectively. In total, 28% of respondents with PNE reported bedwetting daily, 31.6% between 1 and 7 times weekly, and 40.4% between 1 and 4 times monthly; 80% of PNE cases had no history of treatment. The prevalence of PNE in patients with a family history, frequency, urgency, urinary incontinence, and recurrent urinary tract infections was significantly higher than in those without these conditions (P<0.001). PNE was significantly correlated with the PSQI total score (sleep quality) (P=0.011). The SES score was lower and the SDS was higher (P<0.001) in the PNE group than in those without PNE. Conclusions: In mainland China, the PNE prevalence among young adults was found to be high, and PNE had significant effects on physical and mental health. Risk factors included a family history, daytime voiding symptoms, and lack of treatment.