Biochemical Characterization of a GDSL-Motif Esterase from Bacillus sp. K91 with a New Putative Catalytic Mechanism

( Jun Mei Ding ),( Ting Ting Yu ),( Lian Ming Liang ),( Zhen Rong Xie ),( Yun Juan Yang ),( Jun Pei Zhou ),( Bo Xu ),( Jun Jun Li ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.11

The esterase gene Est8 from the thermophilic bacterium Bacillus sp. K91 was cloned and expressed in Escherichia coli. The monomeric enzyme exhibited a theoretical molecular mass of 24.5 kDa and an optimal activity around 50°C at pH 9.0. A model of Est8 was constructed using a hypothetical YxiM precursor structure (2O14_A) from Bacillus subtilis as template. The structure showed an α/β-hydrolase fold and indicated the presence of a typical catalytic triad consisting of Ser-11, Asp-182, and His-185, which were investigated by site directed replacements coupled with kinetic characterization. Asp-182 and His-185 residues were more critical than the Ser-11 residue in the catalytic activity of Est8. A comparison of the amino acid sequence showed that Est8 could be grouped into the GDSL family and further classified as an SGNH hydrolase. Est8 is a new member of the SGNH hydrolase subfamily and may employ a different catalytic mechanism.

Hong Kong Marine Insurance Law Update

( Lian Jun Li ) 고려대학교 법학연구원 2013 The Asian Business Lawyer Vol.12 No.-

This article seeks to offer an overview of the current law on marine insurance in Hong Kong. The article will begin with an introduction to the nature of marine insurance contracts which is based on the concept of indemnity. Marine insurance is also a contract of good faith which gives rise to the duty to disclose all material circumstances and the duty not to make misrepresentation on the part of the insured. The predominant piece of legislation concerning marine insurance is the Marine Insurance Ordinance (Cap. 329). The warranties implied by law together with the effect of the breach of such warranties will then be explored. Hong Kong, like the UK, adopts an absolute compliance regime towards marine warranties which means that any breaches to the warranty whether or not such breach is material or causative of the eventual loss, will completely discharge the insurer of its liabilities from the time of the breach. In relation to direct action, an injured third party will have to overcome a number of hurdles before it can institute a direct claim against the insurer (bypassing the insured). These hurdles include the need to establish and quantify liability against the insured and that the insured must be bankrupt, or wound up in the case of a company. When discussing marine warranties and direct action, the author will look into recent court decisions in Hong Kong and the UK and their respective implications to the shipping industry.

SPECIAL TOPICS IN MARITIME LAW : Marine Insurance Law -General Conditions in Hull, Cargo and P&I Covers

( Lian Jun Li ) 고려대학교 법학연구원 2014 The Asian Business Lawyer Vol.13 No.-

The marine insurance market can represent something of a maze to the un-initiated. Perhaps it is better described as a jigsaw of interlocking covers, often provided by hundreds of individuals or corporate, to make a marine adventure cover whole. The reason for this is largely historic, tracing its routes to the Lloyd’s coffee houses of London, through the American Civil War to the massive expansion of international trade . to this day still heavily reliant on the shipping industry. This article does not intend to provide a complete history of marine insurance, nor a line by line analysis of various hull, cargo and P&I cover. Instead, it will try to provide some historical context to each strand, before reviewing some of the more prevalent clauses and covers in today’s marine underwriting market. It is hoped that the reader will come away from the article with a clearer idea as to who insures what, for how much and why.

Lymph Node Ratio is More Predictive than Traditional Lymph Node Stratification in Lymph Node Positive Invasive Breast Cancer

Bai, Lian-Song,Chen, Chuang,Gong, Yi-Ping,Wei, Wen,Tu, Yi,Yao, Feng,Li, Juan-Juan,Wang, Li-Jun,Sun, Sheng-Rong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis. Methods and Patients: We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (${\leq}0.20$), intermediate-risk (> 0.20 but ${\leq}0.65$), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS. Results: A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P=0.002 in Group A, P<0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A. Conclusions: LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.

Effects of Preemptive Analgesia with Parecoxib Sodium on Haemodynamics and Plasma Stress Hormones in Surgical Patients with Thyroid Carcinoma

Wang, Lian-Dong,Gao, Xia,Li, Jun-Ying,Yu, Hong-Yan,Su, Hai-Wen,Liu, Lian-Zhong,Qi, Jun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Background: To investigate the effects of preemptive analgesia with parecoxib sodium on haemodynamics and plasma stress hormones in surgical patients with thyroid carcinoma. Materials and Methods: Fifty-seven patients with thyroid carcinoma who underwent thyroidectomy selectively in Laiwu Hospital Affiliated to Taishan Medical University and Binzhou People's Hospital were selected and randomly divided into three groups, 19 cases in each group. The control group was intravenously injected 0.9% sodium chloride injection before anesthesia induction; trial group I was intravenously injected with parecoxib sodium 20 min before anesthesia induction; based on trial group I, trial group II was injected with parecoxib sodium again 12 h after surgery. The levels of plasma norepinephrine (NE), cortisol (Cor) and blood glucose before, 12 and 24 h after surgery and changes of haemodynamics before surgery, at the end of surgery and 12, 24 and 48 h after surgery were compared in the three groups. Besides, visual analogue scale (VAS) scores were recorded 4, 8, 12 and 24 h after surgery. Results: 12 and 24 h after surgery, the levels of plasma NE and Cor in three groups rose dramatically (P<0.05 or (P<0.01); The levels of plasma NE and Cor in trial groups I and II were evidently lower than in control group (P<0.05 or P<0.01), and those in trial group II slightly lower than in trial group I. 12 h after surgery, the heart rates (HR) and systolic pressures (SBP) in trial groups I and II increased obviously by comparison to surgery before (P<0.05 or P<0.01), but gradually returned to the preoperative level. HR, SBP and diastolic pressures (DBP) in trial groups I and II at the end of surgery and 12 h after surgery were all lower than in the control group, and significant differences were present (P<0.05 or (P<0.01). At 4, 8, 12 and 24 h after surgery, VAS scores in trial groups I and II were markedly lower than in the control group (P<0.05 or (P<0.01), the scores in trial group II being the lowest. Conclusions: Combined application of parecoxib sodium for preemptive analgesia before anesthesia and after surgery can effectively reduce the levels of plasma stress hormones and improve analgesic effects in surgical patients with thyroid carcinoma, and without conspicuous impact on haemodynamics.

The Gender-Sensitive Social Risk Factors for Internet Addiction in College Undergraduate Students

Xia Lin,Jing-yan Gu,Wan-jun Guo,Ya-jing Meng,Hui-yao Wang,Xiao-jing Li,Wei Deng,Lian-sheng Zhao,Xiao-hong Ma,Ming-li Li,Ting Chen,S,K,Cheng,Tao Li 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.7

Objective The current study aims to explore precipitating and social risk factors for internet addiction (IA) in university undergraduate students, and to provide evidence for interventions and the early prevention of IA in different genders. Methods Four thousand eight hundred and fifty-eight college sophomores completed an online survey on their internet use-related behaviours and social risk factors. Results We found that more male (8.3%) than female students (5.4%) had moderate and severe IA. The main online activity in the moderate and severe IA groups was online gaming in males and online streaming in females. Roommates engaging in similar internetbased entertainment was a risk factor of IA only for males, while not being in a romantic relationship was a risk factor of IA for females only. Infatuation with the internet before college and adjustment problems for college life were shared risk factors for both genders in the mild and moderate IA groups. Conclusion IA was a common phenomenon in college students with shared and unique precipitating and social risk factors in males and females. The gender-sensitive risk factors for IA warranted earlier and individualized intervention and prevention strategies for IA in this population.

Blending of Soybean Oil with Selected Vegetable Oils: Impact on Oxidative Stability and Radical Scavenging Activity

Li, Yang,Ma, Wen-Jun,Qi, Bao-Kun,Rokayya, Sami,Li, Dan,Wang, Jing,Feng, Hong-Xia,Sui, Xiao-Nan,Jiang, Lian-Zhou Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Soybean oil may protect against cancer of the breast and prostate. It may also exert beneficial influence in combination with other oils. Here, blends (20%, v/v) of sea buckthorn oil (SEBO), camellia oil (CAO), rice bran oil (RBO), sesame oil (SEO) and peanut oil (PEO) with soybean oil (SBO) were formulated. Materials and Methods: Oxidative stability (OS) and radical scavenging activity (RSA) of SBO and blends stored under oxidative conditions ($60^{\circ}C$) for 24 days were studied. By blending with different kinds oils, levels of polyunsaturated fatty acids (PUFA) decreased, while monounsaturated fatty acid (MUFA) content increased. Progression of oxidation was followed by measuring peroxide value (PV), p-anisidine (PAV), conjugated dienes (CD) and conjugated trienes (CT). Results: Inverse relationships were noted between PV and OS at termination of storage. Levels of CD and CT in SBO, and blends, increased with increase in time. The impact of SEO as additives on SBO oxidation was the strongest followed by RBO, CAO, SEBO and PNO. Conclusions: Oxidative stability of oil blends was better than SBO, most likely as a consequence of changes in fatty acids and tocopherols' profile, and minor bioactive lipids found in selected oils. The results suggest that these oil blends could contribute as sources of important antioxidant related to the prevention of chronic diseases associated to oxidative stress, such as in cancer and coronary artery disease.

Preparation of High-density YAG/ZrB2 Multi-phase Ceramics by Spark Plasma Sintering

Lian-Meng Zhang,Jie-Guang Song,Jun-Guo Li,Jian-Rong Song 한양대학교 세라믹연구소 2007 Journal of Ceramic Processing Research Vol.8 No.5

ZrB2 and YAG are widely applied because of some excellent properties, but ZrB2 is difficult to prepare as a high-density ceramic, and it is easily oxidized in high temperature air, which limits the application of ZrB2 materials. To obtain high-density for better oxidation resistance ZrB2 ceramic materials, in this paper, Al2O3 and Y2O3 are added into ZrB2 raw material to prepare high-density YAG/ZrB2 multi-phase ceramics by spark plasma sintering. Through the above analysis, it is proposed that 1600oC is regarded as a critical sintering temperature (Tc) to fabricate YAG/ZrB2 multi-phase ceramics. Only if the sintering temperature is higher than Tc, can a nearly full density composite be achieved. The microstructure of sintered YAG/ ZrB2 multi-phase ceramics after 4 minutes at 1600oC is a better compact, the density and relative density are 5.5865 g/cm3 and 99.40% respectively, which indicates that high-density YAG/ZrB2 multi-phase ceramics have been fabricated successfully. ZrB2 and YAG are widely applied because of some excellent properties, but ZrB2 is difficult to prepare as a high-density ceramic, and it is easily oxidized in high temperature air, which limits the application of ZrB2 materials. To obtain high-density for better oxidation resistance ZrB2 ceramic materials, in this paper, Al2O3 and Y2O3 are added into ZrB2 raw material to prepare high-density YAG/ZrB2 multi-phase ceramics by spark plasma sintering. Through the above analysis, it is proposed that 1600oC is regarded as a critical sintering temperature (Tc) to fabricate YAG/ZrB2 multi-phase ceramics. Only if the sintering temperature is higher than Tc, can a nearly full density composite be achieved. The microstructure of sintered YAG/ ZrB2 multi-phase ceramics after 4 minutes at 1600oC is a better compact, the density and relative density are 5.5865 g/cm3 and 99.40% respectively, which indicates that high-density YAG/ZrB2 multi-phase ceramics have been fabricated successfully.

A practical method for simultaneous determination of Poisson’s ratio and Young’s modulus of elasticity of thin films

Jun-yi Sun,Jian-li Hu,Zhou-lian Zheng,Xiao-ting He,Huan-huan Geng 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.12

In this paper, based on the exact analytical solution of axisymmetric deformation of the circular membrane fixed at its edge under the action of uniformly-distributed loads, we propose a new method to be able to simultaneously determine Poisson's ratio and Young's modulus of elasticity for thin films. We also present a set of exact formulas used for simultaneously determining Poisson's ratio and Young's modulus of elasticity for free-standing thin films or coating thin films without residual stresses or pre-tension. This method has the advantages of simplicity and reliability, and it doesn’t involve the substrate effect.

Study on Synthesis of PAEKs Containing Triazole Units through Click Reaction and Their Properties

Lian-jun Wang,Jie Li,Le-yong Wang 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.9

A series of novel linear aromatic ether ketone polymers containing triazole units were synthesized by click chemistry and their structures and properties were characterized by FT-IR, ^1H NMR, GPC, TGA, DSC and WAXD. The results showed that these polymers exhibited relatively small molecular weights distributions,good thermal stability and solvent-repelling which could have potential applications as engineering thermoplastic.