Characterization of Glycerol Dehydrogenase from Thermoanaerobacterium thermosaccharolyticum DSM 571 and GGG Motif Identification

( Liangliang Wang ),( Jiajun Wang ),( Hao Shi ),( Huaxiang Gu ),( Yu Zhang ),( Xun Li ),( Fei Wang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

Glycerol dehydrogenases (GlyDHs) are essential for glycerol metabolism in vivo, catalyzing its reversible reduction to 1,3-dihydroxypropranone (DHA). The gldA gene encoding a putative GlyDH was cloned from Thermoanaerobacterium thermosaccharolyticum DSM 571 (TtGlyDH) and expressed in Escherichia coli. The presence of Mn(2+) enhanced its enzymatic activity by 79.5%. Three highly conserved residues (Asp(171), His(254), and His(271)) in TtGlyDH were associated with metal ion binding. Based on an investigation of glycerol oxidation and DHA reduction, TtGlyDH showed maximum activity towards glycerol at 60°C and pH 8.0 and towards DHA at 60°C and pH 6.0. DHA reduction was the dominant reaction, with a lower Km(DHA) of 1.08 ± 0.13 mM and Vmax of 0.0053 ± 0.0001 mM/s, compared with glycerol oxidation, with a Km(glycerol) of 30.29 ± 3.42 mM and Vmax of 0.042 ± 0.002 mM/s. TtGlyDH had an apparent activation energy of 312.94 kJ/mol. The recombinant TtGlyDH was thermostable, maintaining 65% of its activity after a 2-h incubation at 60°C. Molecular modeling and site-directed mutagenesis analyses demonstrated that TtGlyDH had an atypical dinucleotide binding motif (GGG motif) and a basic residue Arg(43), both related to dinucleotide binding.

Effectiveness and safety of nab- paclitaxel and platinum as first-line chemotherapy for ovarian cancer: a retrospective study

Liangliang Wang,Shuangying Li,Da Zhu,Yu Qin,Xiaoli Wang,Zhenya Hong,Zhiqiang Han 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.4

Objective: To evaluate the effectiveness and safety of nab-paclitaxel plus platinum as first-line chemotherapy for ovarian cancer (OC). Methods: Patients administered platinum combined with nab-paclitaxel as first-line chemotherapy for epithelial OC, fallopian tube cancer, or primary peritoneal cancer from July 2018 to December 2021 were retrospectively evaluated. The primary outcome was progression-free survival (PFS). Adverse events (AEs) were examined. Subgroup analysis was performed. Results: Seventy-two patients (median age, 54.5 years; range, 20.0–79.0 years) were evaluated, including 12 and 60 administered neoadjuvant therapy and primary surgery with subsequent chemotherapy, respectively. The median follow-up duration was 25.6 months, and the median PFS was 26.7 (95% confidence interval [CI]=24.0–29.3) months in the whole patient population. In the neoadjuvant subgroup, the median PFS was 26.7 (95% CI=22.9–30.5) months vs. 30.1 (95% CI=23.1–37.1) months in the primary surgery subgroup. Twenty-seven patients were administered nab-paclitaxel plus carboplatin and had a median PFS of 30.3 (95% CI=not available [NA]–NA) months. The commonest grade 3–4 AEs included anemia (15.3%), white blood cell decreased (11.1%), and neutrophil count decreased (20.8%). No drug-related hypersensitivity reactions occurred. Conclusion: Nab-paclitaxel plus platinum as first-line treatment in OC was associated with a favorable prognosis and was tolerable in patients with OC.

Influence of In-Plane Simple Shear Strain on the Grain Orientation Regulation and Stretch Formability of Pre-twinned AZ31 Magnesium Alloy Sheet

Liangliang Xue,Lifei Wang,Pengbin Lu,Qiang Zhang,Hua Zhang,Guangsheng Huang,Liwei Lu,Liuwei Zheng,Hanuma Reddy Tiyyagura,Hongxia Wang,Shuyong Jiang,Kwang Seon Shin 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

Pre-twin is widely accepted as an efficient method for weakening the basal texture to improve the plasticity of magnesium alloys, particularly for formability. However, the enhancement is limited since the largest Schmid factor (SF) of basal slip cannot be achieved. In-plane simple shear strain is used to control the twin orientation in accordance with Schmid law to further decrease the basal texture and improve the formability of the Mg alloys sheet. Consequently, secondary regulation of initial twin orientation (SRITO) technology, a novel combination procedure, was developed. In this method, the AZ31 Mg alloys sheet is compressed to pre-twins with various volumes (1%, 3%, and 5%), then the twin orientation is regulated by in-plane simple shear strain for the second time. Compared with the as-received sample, the average fracture elongation of the annealed sample with the best properties improves from 15.3 to 28.8%, and the Erichsen value increases from 2.8 to 6.1 mm due to the regulation of twin orientation.

Rapid Detection of Streptococcus mutans Using an Integrated Microfluidic System with Loop-Mediated Isothermal Amplification

Wang Jingfu,Wang Jingyi,Chang Xin,Shang Jin,Wang Yuehui,Ma Qin,Shen Liangliang 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.8

Streptococcus mutans is the primary causative agent of caries, which is one of the most common human diseases. Thus, rapid and early detection of cariogenic bacteria is critical for its prevention. This study investigated the combination of loop-mediated isothermal amplification (LAMP) and microfluid technology to quantitatively detect S. mutans. A low-cost, rapid microfluidic chip using LAMP technology was developed to amplify and detect bacteria at 2.2–2.2 × 106 colony-forming units (CFU)/ml and its detection limits were compared to those of standard polymerase chain reaction. A visualization system was established to quantitatively determine the experimental results, and a functional relationship between the bacterial concentration and quantitative results was established. The detection limit of S. mutans using this microfluidic chip was 2.2 CFU/ml, which was lower than that of the standard approach. After quantification, the experimental results showed a good linear relationship with the concentration of S. mutans, thereby confirming the effectiveness and accuracy of the custom-made integrated LAMP microfluidic system for the detection of S. mutans. The microfluidic system described herein may represent a promising simple detection method for the specific and rapid testing of individuals at risk of caries.

Intrapuparial development and age estimation of Sarcophaga peregrina (Diptera: Sarcophagidae) for postmortem interval estimation

Li Liangliang,Zhang Yanan,Chen Yang,Guo Yi,Wang Yinghui,Hu Gengwang,Kang Chengtao,Jiangfeng Wang,Wang Yu 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

Sarcophaga peregrina Robineau-Desvoidy, 1830 (Diptera: Sarcophagidae) is a widely distributed species in the Palearctic, Oriental and Australian regions. Numerous studies and case reports have confirmed the value of this species in forensic investigations, but methods for estimating the age of the intrapuparial period of this species are lacking. In this study, S. peregrina pupae were sampled at 16 ◦ C, 19 ◦ C, 22 ◦ C, 25 ◦ C, 28 ◦ C, 31 ◦ C, and 34 ◦ C. Morphological changes within the puparium were observed under a stereomicroscope. The results of the study showed that S. peregrina could complete its intrapuparial development at each of the seven tested constant temperatures. As the temperature increased, the average minimum duration of the intrapuparial period of S. peregrina decreased from 706.7 ± 28.1 h at 16 ◦ C to 170.7 ± 4.6 h at 34 ◦ C. The intrapuparial morphological changes of S. peregrina can be divided into 12 sub-stages. While some structures such as the compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen can be used individually to estimate intrapuparial age, we observed all these structures with local magnification photographs and classified the developmental process of these structures into 6–11 stages. The time range for the appearance of each sub-stage or structure was recorded in detail. The results of this study provide important basic data for estimating the minimum postmortem interval using the intrapuparial morphology of S. peregrina.

Influence of oil pipe corrosion defects on the sealing performance of annular BOP

Liangliang Dong,Yuan Tang,Liuyang Wang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.3

Due to corrosion defects on the surface of the oil pipe, the sealing performance of the annular blowout preventer (BOP) decreases, and the leakage of toxic and harmful gases such as H2S and SO2 will threaten the safety of operators on the well. Therefore, this paper establishes the FE model for evaluating the sealing performance of BOP-oil pipe corrosion defects, which is based on the rubber large deformation theory and rubber core sealing mechanism, and designs the experiment of BOP sealing performance to verify the accuracy of the FE model. The sealing performance of BOP sealing oil pipe with corrosion defects is studied. The research results show that the sealing performance of BOP is more sensitive to the axial size of corrosion defects. With the increase of oil pipe outer diameter, the critical size of defects increases continuously. The sensitivity of radial and depth dimensions is low, When for 88.9 mm outer diameter oil pipe, the axial critical size of corrosion defect is 20 mm, the radial critical size is 16 mm and the critical depth is 2 mm. Fit the formula between the outer diameter of oil pipe and the piston increment. According to the formula, the operator can calculate the piston stroke increment required by the BOP to complete the sealing when the oil pipe is corroded.

Fabrication of Columnar NaNbO3‑Based Particles Through Topochemical Microcrystal Conversion

Liangliang Liu,Rui Lv,Zhuangzhuang Guo,Yongqiang Wang 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

The columnar NaNbO3-based particles with a perovskite structure were successfully synthesized through topochemical microcrystal conversion. First, the precursor was fabricated by facile MSS in the Nb2O5–KCl system. A good dispersion and high aspect ratio were satisfed simultaneously with a small amount of SrCO3 and KSr2Nb5O15 (KSN) seed. Then, columnar NaNbO3-based particles, 10 μm in length and 1 μm in diameter, were obtained via the simple molten salt reaction from the precursor. The results of NaNbO3-based ceramics suggested that the as-synthesized NaNbO3-based particles had the good mechanical properties and homogeneous chemical composition.

Novel Prognostic Nomograms for Hepatocellular Carcinoma Patients with Microvascular Invasion: Experience from a Single Center

Liangliang Xu,Lian Li,Peng Wang,Ming Zhang,Yanfang Zhang,Xiangyong Hao,Lvnan Yan,Bo Li,Tianfu Wen,Mingqing Xu 거트앤리버 소화기연관학회협의회 2019 Gut and Liver Vol.13 No.6

Background/Aims: Microvascular invasion (MVI) is an established risk factor for hepatocellular carcinoma (HCC). However, prediction models that specifically focus on the individual prognoses of HCC patients with MVI is lacking. Methods: A total of 385 HCC patients with MVI were randomly assigned to training and validation cohorts in a 2:1 ratio. The outcomes were disease-free survival (DFS) and overall survival (OS). Prognostic nomograms were established based on the results of multivariate analyses. The concordance index (C-index), calibration plots and Kaplan-Meier curves were employed to evaluate the accuracy, calibration and discriminatory ability of the models. Results: The independent risk factors for both DFS and OS included age, tumor size, tumor number, the presence of gross vascular invasion, and the presence of Glisson’s capsule invasion. The platelet-tolymphocyte ratio was another risk factor for OS. On the basis of these predictors, two nomograms for DFS and OS were constructed. The C-index values of the nomograms for DFS and OS were 0.712 (95% confidence interval [CI], 0.679 to 0.745; p<0.001) and 0.698 (95% CI, 0.657 to 0.739; p<0.001), respectively, in the training cohort and 0.704 (95% CI, 0.650 to 0.708; p<0.001) and 0.673 (95% CI, 0.607 to 0.739; p<0.001), respectively, in the validation cohort. The calibration curves showed optimal agreement between the predicted and observed survival rates. The Kaplan-Meier curves suggested that these two nomograms had satisfactory discriminatory abilities. Conclusions: These novel predictive models have satisfactory accuracy and discriminatory abilities in predicting the prognosis of HCC patients with MVI after hepatectomy.

Isolation and Identification of Lactic Acid Bacteria from Traditional Dairy Products in Baotou and Bayannur of Midwestern Inner Mongolia and q-PCR Analysis of Predominant Species

Wang, Dan,Liu, Wenjun,Ren, Yan,De, Liangliang,Zhang, Donglei,Yang, Yanrong,Bao, Qiuhua,Zhang, Heping,Menghe, Bilige Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.4

In this study, traditional culture method and 16S rRNA gene analysis were applied to reveal the composition and diversity of lactic acid bacteria (LAB) of fermented cow milk, huruud and urum from Baotou and Bayannur of midwestern Inner Mongolia. Also, the quantitative results of dominant LAB species in three different types of dairy products from Baotou and Bayannur were gained by quantitative polymerase chain reaction (q-PCR) technology. Two hundred and two LAB strains isolated from sixty-six samples were identified and classified into four genera, namely Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, and twenty-one species and subspecies. From these isolates, Lactococcus lactis subsp. lactis (32.18%), Lactobacillus plantarum (12.38%) and Leuconosto mesenteroides (11.39%) were considered as the dominated LAB species under the condition of cultivating in MRS and M17 medium. And the q-PCR results revealed that the number of dominant species varied from samples to samples and from region to region. This study clearly shows the composition and diversity of LAB existing in fermented cow milk, huruud and urum, which could be considered as valuable resources for LAB isolation and further probiotic selection.

Research of the Exciting Current Detection Method of MCR

Wang Jun,Wei Liangliang,Chen Feng,Nie Dexin,Lu Wenhua 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.5

Magnetic valve controllable reactor (MCR) is a kind of dynamic reactive power compensation device. The exciting current of MCR is one of the important indexes of operating condition of MCR. This paper firstly analyzed the principle of MCR, and deduced the relationship between the exciting current and the output current, verified by MATLAB/SIMULINK. And then an effective method to detect the exciting current was proposed by this paper. The method has the advantages of optical fiber isolation, high detection precision, strong anti-interference, etc. Finally, a 220v/1200var MCR was experimented in detail. The results demonstrate the accuracy of the theoretical analysis.