Dynamic characteristics and test analysis of a new drilling downhole tool with anti-stick-slip features

Jia-lin Tian,Tangjia Zhang,Liming Dai,Wenming Cheng,Lin Yang,Chang-fu Yuan 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.10

A key problem in drill string dynamics is the stick–slip in deep and large displacement horizontal wells that may lead to the decline in drilling performance or cause tool failure, which may eventually cause underground accidents. Therefore, the research on the production safety, ROP, and increased efficiency in relation to stick–slip theory and practical stick–slip reduction is highly relevant, especially in complex drilling conditions. On this basis, this study takes the new constant torque tool as the engineering background and establishes the working mechanism analytical model of stick–slip reduction and torque constant. A helical dynamic model is established to solve the core problem of the constant torque tool. Then, the differential equation of the helical spline drive motion is deduced. The motion of the helical spline mandrel is calculated, and its analytical results are compared with simulation results. Findings show that the laws of angular displacement, angular velocity, axial displacement, and axial velocity are consistent with the simulation results when the helical spline mandrel moves up or down. The established theoretical model can promote the development of drill string dynamics in new drilling conditions. Moreover, the proposed designing methods can provide new ideas for the development of a stick–slip reduction tool. The results can be further used as reference for key parameter determination and stick–slip reduction technology optimization.

Professionals’ experiences and attitudes toward use of Traditional Chinese Medicine in hospice palliative inpatient care units: A multicenter survey in Taiwan

Yu-Jia Lin,Hsiao-Ting Chang,Ming-Hwai Lin,Ru-Yih Chen,Ping-Jen Chen,Wen-Yuan Lin,Jyh-Gang Hsieh,Ying-Wei Wang,Chung-Chieh Hu,Yi-Sheng Liou,Tai-Yuan Chiu,Chun-Yi Tu,Yi-Jen Wang,Bo-Ren Cheng,Tzeng-Ji Ch 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.2

Background: Medical staff may have difficulties in using conventional medicine to manage symptoms among terminally ill patients, including adverse effects of the treatment. Traditional Chinese medicine (TCM) is regarded as a complementary or alternative medicine, and has been increasingly used in the field of palliative medicine in recent years. This study aimed to investigate the experiences of and attitudes toward using TCM among palliative care professionals, and to provide preliminary information about its use in palliative care. Methods: This was a cross-sectional survey study conducted in eight inpatient hospice wards in Taiwan between December 2014 and February 2016. The questionnaire was self-administered, and was analyzed with descriptive statistics including Pearson’s Chi-square test and Fisher’s exact test. Results: A total of 251 palliative care professionals responded to the questionnaire, of whom 89.7% and 88.9% believed that the use of TCM could improve the physical symptoms and quality of life in terminally ill patients, respectively. Overall, 59.8%, of respondents suggested that TCM had rare side effects, and 58.2% were worried that TCM could affect the liver and kidney function of patients. In total, 89.7% and 88.0% of professionals agreed there were no suitable clinical practice guidelines and educational programs, respectively, for TCM use in palliative care. Conclusions: Most of the respondents agreed there was insufficient knowledge, skills-training, and continuing education on the use of TCM in terminally ill patients in Taiwan. These results show that to address patient safety considerations, guidelines about use of TCM in palliative care should be established.

Associations of TNF-RII rs1061622 With Post-Traumatic Stress Disorder and Their Interplays on Serum Lipids Levels in Adolescents

Ji Cheng Zhang,Jin Hua Wang,Jun Yi Liu,Qi Wei Guo,Jia Lin,Yi Lin Shen,Ke Xin Jia,Jia Jing Cai,Guo Ming Su,Ding Zhi Fang 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.11

Objective To verify effects of rs1061622 at tumor necrosis factor-α receptor II (TNF-RII) gene (<i>TNF-RII</i>) on post-traumatic stress disorder (PTSD) and its interactive effects with PTSD on serum lipids levels in adolescents.Methods PTSD was measured by PTSD Checklist-Civilian Version (PCL-C) in 699 adolescent survivors at 6 months after Wenchuan earthquake in China. A polymerase chain reaction and restriction fragment length polymorphism assay were utilized for <i>TNF-RII</i> rs1061622 genotyping followed by verification using DNA sequencing. Serum triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol were tested using routine methods.Results G (deoxyguanine) allele carriers had higher PCL-C scores than TT (deoxythymidine) homozygotes in female subjects. Female adolescents had higher PCL-C scores than male subjects in TT homozygotes. Predictors of PTSD prevalence and severity were different between G allele carriers and TT homozygotes. Subjects with PTSD had lower TG, TG/HDL-C, TC/HDL-C, and higher HDL-C than adolescents without PTSD in male G allele carriers. G allele carriers had higher TG/HDL-C and TC/HDL-C than TT homozygotes in male adolescents without PTSD, and lower TG and TG/HDL-C in male PTSD patients. G allele carriers had higher TG than TT homozygotes only in female adolescents without PTSD.Conclusion These results suggest reciprocal actions of <i>TNF-RII</i> rs1061622 with other factors on PTSD severity, interplays of <i>TNF-RII</i> rs1061622 with PTSD on serum lipid levels, and novel treatment strategies for PTSD and comorbidities of PTSD with hyperlipidemia among adolescents with different genetic backgrounds of <i>TNF-RII</i> rs1061622 after experiencing traumatic events.

Antimycobacterial Activity of Fusaric Acid from a Mangrove Endophyte and its Metal Complexes

Jia-Hui Pan,Yi Chen,Yu-Hong Huang,Yi-Wen Tao,Jun Wang,Yan Li,Yi Peng,Tao Dong,Xiao-Min Lai,Yong-Cheng Lin 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.7

Due to the increasing prevalence of multidrug-resistant Mycobacterium tuberculosis, there is an urgent need for new antituberculosis drugs that have novel mechanisms of action. As part of our ongoing search for antimycobacterial metabolites from mangrove endophytes, chemical analysis of the active extract of a strain of Fusarium sp. was performed, which led to the isolation of fusaric acid as the predominant constituent. A variety of metal complexes of fusaric acid were prepared. Antimycobacterial assays showed that Cadmium (II) and Copper (II) complexes exhibited potent inhibitory activity against the M. bovis BCG strain [minimum inhibitory concentration (MIC) = 4 μg/mL] and the M. tuberculosis H37Rv strain (MIC = 10 μg/mL), respectively. This is the first report of the antimycobacterial activity of the mangrove Fusarium metabolite and its coordinating metal complexes.

Lightweight and Ultrastrong Polymer Foams with Unusually Superior Flame Retardancy

Xu, Linli,Xiao, Linhong,Jia, Pan,Goossens, Karel,Liu, Peng,Li, Hui,Cheng, Chungui,Huang, Yong,Bielawski, Christopher W.,Geng, Jianxin American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.31

<P>High-performance flame-retardant materials are urgently needed to address outstanding issues that pertain to safety. Traditional flame retardants are toxic to the environment and/or lack the physical properties required for use in many contemporary applications. Here, we show that isocyanate-based polyimide (PI) foam, a flammable material, can exhibit unusually superior flame retardancy as well as, other excellent properties, such as being lightweight and displaying high mechanical strength, by incorporating red phosphorus (RP)-hybridized graphene. The covalent bonds formed between the graphene platelets and the PI matrix provide the resultant PI foam with a specific Young's modulus (83 kNm kg(-1)) that is comparable to or even higher than those displayed by state-of-the-art foams, including silica aerogels, polystyrene foams, and polyurethane foams. In addition, even a low content of the RP -hybridized graphene (2.2 wt %) results in an exceptionally higher limiting oxygen index (39.4) than those of traditional flame-retardant polymer-based materials (typically 20-30). The resultant PI foam also exhibits thermal insulation properties that are similar to that of air. Moreover, the RP -hybridized graphene is prepared using a one-step ball milling process in 100% yield, and does not require solvent or produce waste. The preparation of the flame-retardant PI foams can be scaled as the starting materials are commercially available and the techniques employed are industrially compatible.</P>

Effects of Ginsenosides Rg1 on Osteoblasts Cultured with Ti Particles

( Yu Lin ),( Yin Sheng Wu ),( Jia Cheng He ),( Yun Mei Huang ),( Yan Ping Lin ) 한국응용약물학회 2012 Biomolecules & Therapeutics(구 응용약물학회지) Vol.20 No.1

The aim of this study was to explore the role and effect of ginsenosides Rg1 on osteoblasts cultured with Ti particles. Osteoblasts from neonatal rats were cultured with particles and different doses of Rg1, the main active ingredient in ginsenosides Rg1. We found that the COX-2, PGE2, TNF-α, IL-1, and IL -6 concentrations in the medium of cells cultured with Ti particles significantly increased as compared with that of the control cells (p<0.05 or p<0.01). In addition, cells cultured with Ti particles alone exhibited the highest concentrations of these molecules. The PGE2, TNF-α, IL-1, and IL-6 levels in the medium of cells cultured with Rg1 were in between those of the control cells and the cells cultured with Ti particles alone. The IL-1ra level in the group cultured with Ti and medium-dose Rg1 was the highest followed by the cells cultured with Ti and high-dose Rg1 and those cultured with Ti and low-dose Rg1 (p<0.05). In conclusion, ginsenosides can reduce the levels of inflammatory cytokines produced by osteoblasts on induction with Ti particles and can prevent prosthesis loosening.

Perioperative considerations for COVID-19 patients: lessons learned from the pandemic -a case series-

Yek Jia Lin Jacklyn,Kiew Sheng Chuu Anne,Ngu James Chi-Yong,Lim Jimmy Guan Cheng 대한마취통증의학회 2020 Korean Journal of Anesthesiology Vol.73 No.6

Background: As the coronavirus disease 2019 (COVID-19) pandemic spreads globally, hospitals are rushing to adapt their facilities, which were not designed to deal with infections adequately. Here, we present the management of a suspected COVID-19 patient. Case: A 66-year-old man with a recent travel history, infective symptoms, and chest X-ray was presented to our hospital. Considering his septic condition, we decided to perform an emergency surgery. The patient was given supplemental oxygen through a face mask and transported to an operating theatre on a plastic-covered trolley. An experienced anesthetist performed rapid sequence intubation using a video laryngoscope. Due to the initial presentation of respiratory distress, the patient remained intubated after surgery to avoid re-intubation. Precautions against droplet, contact, and airborne infection were instituted. Conclusions: Our objective was to facilitate surgical management of patients with known or suspected COVID-19 while minimizing the risk of nosocomial transmission to healthcare workers and other patients.

Fabrication of a Novel Core-Shell Gene Delivery System Based on a Brush-Like Polycation of α, β-Poly (L-Aspartate-Graft-PEI)

Yu, Jia-Hui,Quan, Ji-Shan,Kwon, Jung-Taek,Xu, Cheng-Xiong,Sun, Bo,Jiang, Hu-Lin,Nah, Jae-Woon,Kim, Eun-Mi,Jeong, Hwan-Jeong,Cho, Myung-Haing,Cho, Chong-Su Springer-Verlag 2009 Pharmaceutical research Vol.26 No.9

Molecular characterization of duck enteritis virus CHv strain UL49.5 protein and its colocalization with glycoprotein M

Meng Lin,Renyong Jia,Mingshu Wang,Xinghong Gao,Dekang Zhu,Shun Chen,Mafeng Liu,Zhongqiong Yin,Yin Wang,Xiaoyue Chen,Anchun Cheng 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.3

The UL49.5 gene of most herpesviruses is conserved andencodes glycoprotein N. However, the UL49.5 protein ofduck enteritis virus (DEV) (pUL49.5) has not been reported. In the current study, the DEV pUL49.5 gene was firstsubjected to molecular characterization. To verify thepredicted intracellular localization of gene expression, therecombinant plasmid pEGFP-C1/pUL49.5 was constructedand used to transfect duck embryo fibroblasts. Next, therecombinant plasmid pDsRed1-N1/ glycoprotein M (gM)was produced and used for co-transfection with thepEGFP-C1/pUL49.5 plasmid to determine whether DEVpUL49.5 and gM (a conserved protein in herpesviruses)colocalize. DEV pUL49.5 was thought to be an envelopeglycoprotein with a signal peptide and two transmembranedomains. This protein was also predicted to localize in thecytoplasm and endoplasmic reticulum with a probability of66.7%. Images taken by a fluorescence microscope atdifferent time points revealed that the DEV pUL49.5 andgM proteins were both expressed in the cytoplasm. Overlapof the two different fluorescence signals appeared 12 h aftertransfection and continued to persist until the end of theexperiment. These data indicate a possible interaction between DEV pUL49.5 and gM.

Naringin and Naringenin Relax Rat Tracheal Smooth by Regulating BKCa Activation

Rui Shi,Jia-Wen Xu,Zi-Ting Xiao,Ruo-Fei Chen,Yi-Lin Zhang,Jia-Bi Lin,Ke-Ling Cheng,Gu-Yi Wei,Pei-Bo Li,Wen-Liang Zhou,Wei-Wei Su 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.9

Naringin and its aglycone, naringenin, occur naturally in our regular diet and traditional Chinese medicines. This study aimed to detect an effective therapeutic approach for cough variant asthma (CVA) through evaluating the relaxant effect of these two bioactive herbal monomers as antitussive and antiasthmatic on rat tracheal smooth muscle. The relaxant effect was determined by measuring muscular tension with a mechanical recording system in rat tracheal rings. Cytosolic Ca2+ concentration was measured using a confocal imaging system in primary cultured tracheal smooth muscle cells. In rat tracheal rings, addition of both naringin and naringenin could concentration dependently relax carbachol (CCh)-evoked tonic contraction. This epithelium-independent relaxation could be suppressed by BaCl2, tetraethylammonium, and iberiotoxin (IbTX), but not by glibenclamide. After stimulating primary cultured tracheal smooth muscle cells by CCh or high KCl, the intracellular Ca2+ increase could be inhibited by both naringin and naringenin, respectively. This reaction was also suppressed by IbTX. These results demonstrate that both naringin and naringenin can relax tracheal smooth muscle through opening big conductance Ca2+-activated K+ channel, which mediates plasma membrane hyperpolarization and reduces Ca2+ influx. Our data indicate a potentially effective therapeutic approach of naringin and naringenin for CVA.