Fracture behavior of cylindrical sandstone specimens with two pre-existing flaws: experimental investigation and PFC3D simulation

Yan-Hua Huang,Sheng-Qi Yang,Guo-Qing Chen,Bo Meng 한국지질과학협의회 2022 Geosciences Journal Vol.26 No.1

It is important to analyze the rock crack initiation, propagation and coalescence in fractured rock mass. At present, the 3D crack evolution process of pre-flawed rock has not been comprehensively studied during the deformation. In this study, uniaxial compression tests were carried out on cylindrical sandstone specimens with two pre-existing flaws with various ligament inclination angles. The crack evolution process at the front surface of the specimen was analyzed by photographic and AE monitoring. In addition, a 3D discrete element modelling was conducted to explore the spatial crack evolution behaviors during compressive loading. Both the numerical strength and final failure modes of specimens were consistent with those obtained in the laboratory experiment. The numerical simulation results revealed that the internal crack distribution was not always identical along the thickness direction. Two types of crack coalescence were identified. The experimental and numerical results enhance the understanding of 3D crack evolution mechanism of fractured rock under external loading.

Associations of Plasma Glucagon Levels with Estimated Glomerular Filtration Rate, Albuminuria and Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus

Hua-Xing Huang,Liang-Lan Shen,Hai-Yan Huang,Li-Hua Zhao,Feng Xu,Dong-Mei Zhang,Xiu-Lin Zhang,Tong Chen,Xue-Qin Wang,Yan Xie,Jian-Bin Su 대한당뇨병학회 2021 Diabetes and Metabolism Journal Vol.45 No.6

Background: Type 2 diabetes mellitus (T2DM) is characterized by elevated fasting glucagon and impaired suppression of postprandial glucagon secretion, which may participate in diabetic complications. Therefore, we investigated the associations of plasma glucagon with estimated glomerular filtration rate (eGFR), albuminuria and diabetic kidney disease (DKD) in T2DM patients.Methods: Fasting glucagon and postchallenge glucagon (assessed by area under the glucagon curve [AUCgla]) levels were determined during oral glucose tolerance tests. Patients with an eGFR <60 mL/min/1.73 m2 and/or a urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g who presented with diabetic retinopathy were identified as having DKD.Results: Of the 2,436 recruited patients, fasting glucagon was correlated with eGFR and UACR (r=–0.112 and r=0.157, respectively; P<0.001), and AUCgla was also correlated with eGFR and UACR (r=–0.267 and r=0.234, respectively; P<0.001). Moreover, 31.7% (n=771) presented with DKD; the prevalence of DKD was 27.3%, 27.6%, 32.5%, and 39.2% in the first (Q1), second (Q2), third (Q3), and fourth quartile (Q4) of fasting glucagon, respectively; and the corresponding prevalence for AUCgla was 25.9%, 22.7%, 33.7%, and 44.4%, respectively. Furthermore, after adjusting for other clinical covariates, the adjusted odds ratios (ORs; 95% confidence intervals) for DKD in Q2, Q3, and Q4 versus Q1 of fasting glucagon were 0.946 (0.697 to 1.284), 1.209 (0.895 to 1.634), and 1.521 (1.129 to 2.049), respectively; the corresponding ORs of AUCgla were 0.825 (0.611 to 1.114), 1.323 (0.989 to 1.769), and 2.066 (1.546 to 2.760), respectively. Additionally, when we restricted our analysis in patients with glycosylated hemoglobin <7.0% (n=471), we found fasting glucagon and AUCgla were still independently associated with DKD.Conclusion: Both increased fasting and postchallenge glucagon levels were independently associated with DKD in T2DM patients.

Strength failure behavior of granite containing two holes under Brazilian test

Huang, Yan-Hua,Yang, Sheng-Qi,Zhang, Chun-Shun Techno-Press 2017 Geomechanics & engineering Vol.12 No.6

A series of Brazilian tests under diameter compression for disc specimens was carried out to investigate the strength and failure behavior by using acoustic emission (AE) and photography monitoring technique. On the basis of experimental results, load-displacement curves, AE counts, real-time crack evolution process, failure modes and strength property of granite specimens containing two pre-existing holes were analyzed in detail. Two typical types of load-displacement curves are identified, i.e., sudden instability (type I) and progressive failure (type II). In accordance with the two types of load-displacement curves, the AE events also have different responses. The present experiments on disc specimens containing two pre-existing holes under Brazilian test reveal four distinct failure modes, including diametrical splitting failure mode (mode I), one crack coalescence failure mode (mode II), two crack coalescences failure mode (mode III) and no crack coalescence failure mode (mode IV). Compared with intact granite specimen, the disc specimen containing two holes fails with lower strength, which is closely related to the bridge angle. The failure strength of pre-holed specimen first decreases and then increases with the bridge angle. Finally, a preliminary interpretation was proposed to explain the strength evolution law of granite specimen containing two holes based on the microscopic observation of fracture plane.

The effi cacy of daily chlorhexidine bathing for preventing healthcare-associated infections in adult intensive care units

( Hua-ping Huang ),( Bin Chen ),( Hai-yan Wang ),( Me He ) 대한내과학회 2016 The Korean Journal of Internal Medicine Vol.31 No.6

Background/Aims: Healthcare-associated infections (HAIs) in critically ill patients with prolonged length of hospital stay and increased medical costs. The aim of this study is to assess whether daily chlorhexidine gluconate (CHG) bathing will significantly reduce the rates of HAIs in adult intensive care units (ICUs). Methods: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched until December 31, 2014 to identify relevant studies. Two authors independently reviewed and extracted data from included studies. All data was analyzed by Review Manager version 5.3. Results: Fifteen studies including three randomized controlled trials and 12 quasi- experimental studies were available in this study. The outcomes showed that daily CHG bathing were associated with significant reduction in the rates of primary outcomes: catheter-related bloodstream infection (risk ratio [RR], 0.44; 95% confidence interval [CI], 0.32 to 0.63; p < 0.00001), catheter-associated urinary tract infection (RR, 0.68; 95% CI, 0.52 to 0.88; p = 0.004), ventilator-associated pneumonia (RR, 0.73; 95% CI, 0.57 to 0.93; p = 0.01), acquisition of methicillin-resistant Staphylococcus aureus (RR, 0.78; 95% CI, 0.68 to 0.91; p = 0.001) and vancomycin-resistant Enterococcus (RR, 0.56; 95% CI, 0.31 to 0.99; p = 0.05). Conclusions: Our study suggests that the use of daily CHG bathing can signifi- cantly prevent HAIs in ICUs. However, more well-designed studies are needed to confirm these findings.

Optimal magnetoelectric coupling performance of Terfenol-D/PZT composites in resonance state under bias magnetic field

Huang Bin,Zhu Weihao,Hua Licheng,Wang Ji,Guo Yan 한국물리학회 2022 Current Applied Physics Vol.41 No.-

Laminated magnetoelectric (ME) composites with various thickness ratios were optimized, fabricated and experimentally investigated in this work. The Terfenal-D/PZT specimens with optimal thickness ratio between the magnetostrictive phase and piezoelectric phase, and two other values were tested for their ME coupling performance. The coupling voltage output increases linearly with the increase of DC bias magnetic field. The ME voltage coefficient increases more than 100 times in the resonance state for the optimal laminate. The DC bias magnetic field affects the ME voltage coefficient significantly, and also has little effect on the resonant frequency. The strength of AC magnetic field also slightly affects the ME voltage coefficient in resonance state, but does not affect the resonant state under which the same DC magnetic field is required. The experimental results can help understand the coupling performance of ME composite under bias magnetic field and prompt the application of ME devices.

Efficacy and Safety of the Safe Triangular Working Zone Approach in Percutaneous Vertebroplasty for Spinal Metastasis

Yan Bi Cong,Fan Yan Feng,Tian Qing Hua,Wang Tao,Huang Zhi Long,Song Hong Mei,Li Ying,Jiao Lei,Wu Chun Gen 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.9

Objective: This study aimed to assess the technical feasibility, efficacy, and safety of the safe triangular working zone (STWZ) approach applied in percutaneous vertebroplasty (PV) for spinal metastases involving the posterior part of the vertebral body. Materials and Methods: We prospectively enrolled 87 patients who underwent PV for spinal metastasis involving the posterior part of the vertebral body, with or without the STWZ approach, from January 2019 to April 2022. Forty-nine patients (27 females and 22 males; mean age ± standard deviation [SD], 57.2 ± 11.6 years; age range, 31–76 years) were included in group A (with STWZ approach), accounting for 54 vertebrae. Thirty-eight patients (18 females and 20 males; 59.1 ± 10.9 years; 29–81 years) were included in group B (without STWZ approach), accounting for 57 vertebrae. Patient demographics, procedure-related variables, and pain relief as assessed using the visual analog scale (VAS) were collected at different time points. Tumor recurrence in the vertebrae after PV was analyzed using Kaplan–Meier curves. Results: The STWZ approach was successful from T1 to L5 without severe complications. Cement filling was satisfactory in 47/54 (87.0%) and 25/57 (43.9%) vertebrae in groups A and B, respectively (p < 0.001). Cement leakage was not significantly different between groups A and B (p = 1.000). Mean VAS score ± SD before and 1 week and 1, 3, 6, 9, and 12 months after PV were 7.6 ± 1.8, 4.2 ± 2.0, 2.7 ± 1.9, 1.9 ± 1.5, 1.7 ± 1.4, 1.7 ± 1.1, and 1.6 ± 1.3, respectively, in group A and 7.2 ± 1.7, 4.0 ± 1.3, 3.4 ± 1.6, 2.4 ± 1.2, 1.8 ± 1.0, 1.4 ± 0.5, and 1.7 ± 0.9, respectively, in group B. Kaplan–Meier analysis showed a lower tumor recurrence rate in group A than in group B (p = 0.001). Conclusion: The STWZ approach may represent a new, safe, alternative/auxiliary approach to target the posterior part of the vertebral body in the PV for spinal metastases.

Two mitochondrial genomes of genus Megacampsomeris Betrem, 1928 (Hymenoptera: Scoliidae) with their phylogenetic implications

Huang Li-Sheng,Liu Zhen,Chen Hua-Yan,Chen Xue-Xin 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

We determined two mitochondrial genomes of genus Megacampsomeris Betrem, 1928, i.e., M. binghami (Betrem, 1928) with 16,461 bp and M. farrenwhitei (Betrem, 1928) with 15,834 bp in length respectively and anotated the sequence of M. prismatica (Smith, 1855). These sequence all possess 37 mitochondrial genes, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs) including one extra trnM gene while missing trnK gene, and two ribosomal RNA (rRNA) genes separately. Gene rearrangement showed inversion event involing protein-coding and tRNA genes. The protein-coding genes of 18 species representing seven superfamilies and 12 families from Aculeata were used for phylogenetic analysis by maximum likelihood (ML) analysis and Bayesian inference (BI), with Cotesia vestalis from Braconidae and Hyposoter sp. from Ichneumonidae was as outgroups. M. prismatica was more closer to M. binghami than M. farrenwhitei in our inferences. Consistent with previous studies, our results supported paraphyly of the superfamily Chrysidoidea and a sister group relationship between Formicoidea and Vespoidea, but failed to recover the monophyly of superfamilies Apoidea and Pompiloidea.

Micellization behavior of binary mixtures of amino sulfonate amphoteric surfactant with different octylphenol polyoxyethylene ethers in aqueous salt solution: Both cationic and hydrophilic effects

Zhao Hua Ren,Jing Huang,Yue Luo,Yan Cheng Zheng,Ping Mei,Lu Lai,Yan Ling Chang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

The effect of different valent inorganic cations and the hydrophilic group of surfactant on themicellization behavior of binary surfactant mixtures constituted by an amphoteric surfactant, sodium3-(N-dodecyl ethylenediamino)-2-hydropropyl sulfonate (C12AS), and three nonionic surfactantsoctylphenol polyoxyethylene ether (OP-n) with different numbers of oxyethylene glycol ethers (n),namely, OP-10, OP-7, and OP-4 was investigated in aqueous solution. These inorganic cations includeNa+, K+, Mg2+, Ca2+, Ba2+, Al3+ and Fe3+. Both the tensiometry and the UV–vis spectrophotometry usingpyrene as a probe were adopted to determine the critical micelle concentrations (cmc) of individual ormixed surfactants. Interaction parameters between two surfactants and other parameters were obtainedbased on the regular solution theory, the pseudophase separation model, Rubingh’s model, etc. Thermodynamic parameters including Gibbs energy of micellization and thermodynamic stability werealso calculated by both the equation proposed by Molyneux et al. and Maeda’s treatment, respectively. The effect of different valent cations on both the mixed cmc of surfactant mixtures and the molar fractionof C12AS in mixed micelle (X1) can be explained theoretically by the salting-out effect, electrostaticinteraction and steric effect. For three binary surfactant mixtures, the chain length of hydrophilic groupof surfactant results in different micellization behaviors. On adding salts, the interaction parametersshow that there exists a synergistic effect between two surfactants, and the effect increases withincreasing the ratio of valence (Z) and atom radius (R) of cation, especially, for the C12AS/OP-4 mixture. With increasing the Z/R value of cation, a deviation of X1 from the ideal value shows a divergence forthree binary surfactant mixtures because of different hydrophilicities of surfactant. Thermodynamicparameters indicate that the addition of cations with a large Z/R value can be contributive moreeffectively to the formation of stable mixed micelle than the case in the presence of cations with a smallZ/R value.

Rapid Detection of Ovarian Cancer from Immunized Serum Using a Quartz Crystal Microbalance Immunosensor

Chen, Yan,Huang, Xian-He,Shi, Hua-Shan,Mu, Bo,Lv, Qun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Background: The objective of this study was to measure the antibody content of NuTu-19 ovarian cancer cells in serum samples using a quartz crystal microbalance (QCM) immunosensor. Materials and Methods: NuTu-19 cells were first cultured onto the electrode surfaces of crystals in Dulbecco's modified Eagle medium, and then specified amounts of immunized serum samples of immunized rabbit were also added. The change in mass caused by specific adsorbtion of antibodies of NuTu-19 to the surfaces of the crystals was detected. Results: The change in resonance frequency of crystals caused by immobilization of NuTu-19 cells was from 83 to 429Hz. The antibody content of NuTu-19 detected was 341ng/ul. The frequency shifts were linearly dependent on the amount of antibody mass in the range of 69 to 340ng. The positive detection rate and the negative detection rate were 80% and 100%, respectively. Conclusion: This immunoassay provides a viable alternative to other early ovarian cancer detection methods and is particularly suited for health screening of the general population.

Association between Metabolic Syndrome and Microvascular Complications in Chinese Adults with Type 1 Diabetes Mellitus

Qianwen Huang,Daizhi Yang,Hongrong Deng,Hua Liang,Xueying Zheng,Jinhua Yan,Wen Xu,Xiangwen Liu,Bin Yao,Sihui Luo,Jianping Weng 대한당뇨병학회 2022 Diabetes and Metabolism Journal Vol.46 No.1

Background: Both type 1 diabetes mellitus (T1DM) and metabolic syndrome (MetS) are associated with an elevated risk of morbidity and mortality yet with increasing heterogeneity. This study primarily aimed to evaluate the prevalence of MetS among adult patients with T1DM in China and investigate its associated risk factors, and relationship with microvascular complications.Methods: We included adult patients who had been enrolled in the Guangdong T1DM Translational Medicine Study conducted from June 2010 to June 2015. MetS was defined according to the updated National Cholesterol Education Program criterion. Logistic regression models were used to estimate the odds ratio (OR) for the association between MetS and the risk of diabetic kidney disease (DKD) and diabetic retinopathy (DR).Results: Among the 569 eligible patients enrolled, the prevalence of MetS was 15.1%. While female gender, longer diabetes duration, higher body mass index, and glycosylated hemoglobin A1c (HbA1c) were risk factors associated with MetS (OR, 2.86, 1.04, 1.14, and 1.23, respectively), received nutrition therapy education was a protective factor (OR, 0.46). After adjustment for gender, age, diabetes duration, HbA1c, socioeconomic and lifestyle variables, MetS status was associated with an increased risk of DKD and DR (OR, 2.14 and 3.72, respectively; both P<0.05).Conclusion: Although the prevalence of MetS in adult patients with T1DM in China was relatively low, patients with MetS were more likely to have DKD and DR. A comprehensive management including lifestyle modification might reduce their risk of microvascular complications in adults with T1DM.