Uniaxial Compression Properties and Compression Fatigue Performance of Selective Laser Melted Ti–6Al–4V Cellular Structure

Ming‑Wei Wu,Jhewn‑Kuang Chen,Mo‑Kai Tsai,Pei Wang,Tien‑Lin Cheng,Bo‑Huan Lin,Po‑Hsing Chiang,Annadurai Dhinakar 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.1

The selective laser melted (SLM) Ti–6Al–4V cellular solid is a promising material in biomedical and other applications. The mechanical properties of the SLM Ti–6Al–4V cellular material are predominantly controlled by the design of the cellular structure. The objective of this study was to investigate the uniaxial compressive properties and compressive fatigueperformance of the SLM Ti–6Al–4V cellular solid with a new cuboctahedron unit cell reinforced by four diagonal strutsand two horizontal struts along the X and Y axes. The infuences of hot isostatic pressing (HIP) on the various mechanicalproperties were also examined. The results showed a smoother stress–strain curve and fewer stress oscillations in the HIPspecimen than in the SLM specimen. The HIP process slightly decreased the yield strength of the SLM sample from 55 to52 MPa. Under uniaxial compressive stress, the SLM and HIP specimens exhibited layer-by-layer fracture and diagonalshear fracture, respectively. Furthermore, the HIP treatment signifcantly increased the fatigue performance and improved thefatigue endurance ratio at 106cycles from 0.15 to 0.35. The HIP treatment contributed to several positive efects, includingphase transformation from brittle α′ to α + β, the elimination of strut porosity and residual stress, an increase in lath size,and a better combination of strength and ductility, thereby improving the fatigue performance. The efects of stress mode onthe fracture mechanism were also clarifed using in situ observation in combination with digital image correlation.

Blocking of Cell Proliferation, Cytokines Production and Genes Expression Following Administration of Cordyceps Sinensis in the Bronchoalveolar Lavage Fluids Cells

Kuo, Yuh-Chi,Wu, Chia-Lin,Tasi, Wei-Jern,Wang, Jir-Yenn,Chang, Shi-Chung,Lin, Ching-Yuang,Shiao, Ming-Shi 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Yuh-Chi Kuo¹,Chia-Lin Wn¹,Wei-jern Tasi¹,Jir-Yenn Wang²,Shi-Chung Chang₃,Ching-Yung Lin⁴,and Ming-Shi Shiao⁴¹National Research Institute of Chinese Medicine, ²Department of Biology,Fu Jen University, ³Department of Chest, ⁴Department of Pediatrics, □De[art,amt of Medical Research and Education. Taipei Veterans General Hospital, Taipei, Taiwan Yuh-Chi Kuo¹,Chia-Lin Wn¹,Wei-jern Tasi¹,Jir-Yenn Wang²,Shi-Chung Chang²,Ching-Yung Lin³,and Ming-Shi Shiao⁴.¹National Research Institute of Chinese Medicine, ²Department of Biology,Fu Jen University, ³Department of Chest, ⁴Department of Pediatrics, □De[art,amt of Medical Research and Education. Taipei Veterans General Hospital, Taipei, Taiwan. Blocking of Cell Proliferation, Cytokines Production and Genes Expression Following Administration of Cordyceps sinensis in the Bronchoalveolar Lavage Fluids Cells. Proceedings of international Symposium on East-West Medicine, Seoul. 44-64, 1999.-Cordyceps sinensis is a major parasitic fungus on larva of Lepidoptera. It is one of the well know fungi used in traditional Chinese medicine for treatment asthma, lung and kideney diseases. Many fungi belonging to the genus Cordyceps have been demonstrated to produce natural products with various biological activities. Reported biological activities of genus cordyceps include:(a)inhibition of DNA and RNA synthesis;(b)enhancement of cell differentiation;(c)restruction of cytoskeleton;(d)inhibition of protein kinase activity;(e)antitumor activity on bladder, colon, lung carcinoma as well as fibroblastoma;(f)inhibition of the infection and revers transciptase activity of human immunodeficiency virus type 1; and(g) inhibition of methylation of nucleic acid. Thus, it is suggested that the extracts of Cordyceps sp. Contain antitumor, antiviral, and many other biological activities. In our previous studies, we proved that C. sinensis contains the antitumor and immunomodulatory agents. In the present studies, effects of C. sinensis on bronchoalveolar lavage fluids(BAL)cells were demonstrated. The crude methanolic extracts of C. sinensis were fractionated into 15 fractions by silica gel column chromatography. Effects of various fraction on BAL cells proliferation and lipopolysaccharide(LPS) stimulated interleukin-1β(IL-8),platelet activating factor(PAF), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α),and interleukin-8(IL-8) production on BAL cells were determined. The result indicated that the CS-19-22 fraction suppressed BAL cells proliferation activated by LPS. The median inhibitory concentration(IC50) was 6㎍/ml. The CS-19-22 fraction also decreased IL-1β,PAF,IL-6, TNF-αand IL-8 production.The results of revers transcription-polymerase chain reaction(RT-PCR) demonstrated that the CS-19-22 fraction did not affect IL-1β,PAF,IL-6, TNF-α,and IL-8 mRNAs expression in BAL cells activated by LPS. By contrast, it inhibited the IL-10 mRNA expression but enhanced IFN-γand IL-12 mRNAs expression in activated BAL cells. Moreover, the CS-19-22 fraction blocked PAF-induced platelet aggregation. It is unlikely that cytotoxicity was involved. Because no cell deths were observable. We hypothesize that inhibitory mechanisms of CS-19-22 on BAL cells proliferation may be related to the impairments of gene expression and production of cytokines in BAL cells. The explanation of C. sinensis antiasthma function may involved the following(1)C.sinenesis contained immunomodulatory agents that stimulated IFN-γand IL-12 expression in TH1cells.(2)Enhanced secretion of IFN-γand IL-12 will inhibit the Tγcells immune responses Ex. Decreasing of IL-6 and IL-10 production.(3) The impairments of cytokines production in TH2 cells suppressed th BAL cells proliferation then more cytokines production Ex.IL-1β,PAF,IL-6,TNF-αand IL-8 in activated BAL cells were decreased. (4)The suppression of TH2cells immune responses will inhibit the growth and differentiation of B cells then IgE production will be decreased. (5)Reduced production of IgE will decreased asthma attack occurring in individuals. However, the results of the present study suggested that C. sinensis may also have acted to treat asthma in part by inhibiting BAL cells proliferation and cytokine gene expression and production. Future, experiments with treatment of animals with asthma with C. sinensis will be necessary to defined whether C. sinensis can reduce asthma injury. Plans are underway for the isolation of pure principal growth inhibitors and their mechanisms of action are subjected for further study.

Stratigraphic Sequence and Deposition-affected Compressibility of Fine-grained Sediments in the Ancient Yellow River Delta during the Late Pleistocene and Holocene

Ming-Zhi Zhao,Qiang Luo,Liang-Wei Jiang,Ming Wei 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.1

To investigate the stratigraphic sequence in the ancient Yellow River Delta and further discuss the correlation of compressibility of undisturbed soils with depositional environments, two boreholes were drilled at Liyao test site in Cangzhou, Hebei Province, China. Some basic tests regarding to index properties were performed on sediments from one borehole, and oedometer test was conducted for the “undisturbed samples” collected from the other. The stratigraphic sequence in the study area is classified into four depositional systems in terms of sedimentation environment. Evaluation of sample disturbance shows that the “undisturbed samples” for oedometer test are just slightly disturbed in the sampling process. Since overall compressibility can be divided into intrinsic compressibility and additional one, the environmental factors that can affect soil microstructure are closely correlated with additional compressibility. Thus, the influencing mechanism of depositional rate on additional void index ΔIv was investigated quantitatively. Moreover, the relationship between floating range of yield stress and buried depth is established. Then, the additional compressibility of undisturbed samples can be evaluated with depositional rate and buried depth. Finally, the predicted overall compression curve with the proposed method in this study is compared with the measured curve to verify the reasonability and feasibility.

Synthesis of PdP Nanoparticles as Electrocatalysts for Hydrogen Evolution Reaction in an Alkaline Medium

Ming Zhao,Ming Zhao,Bin Tong,Zinan Kang,Yanfang Wu,Wei Ding,Baoming Feng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

The synthesis of PdP nanoparticles (NPs) using triphenylphosphine as a phosphorus precursor was investigated. The electrocatalytic performance of PdP NPs in hydrogen evolution reaction in an alkaline medium was measured. It can be concluded that when the current density is 10 mA cm -2, the overpotential produced by Pd3P0.95 NPs is 75mV which is 185mV lower than that produced by commercial Pd/C. The mass activity of Pd3P0.95 NPs is more than twice as high as that of commercial Pd/C. The work indicates that PdP nanomaterials could be a potential catalyst for water splitting.

Microstructures, Mechanical Properties, and Fracture Behaviors of Metal-Injection Molded 17-4PH Stainless Steel

Ming-Wei Wu,Zeng-Kai Huang,Chun-Feng Tseng,Kuen-Shyang Hwang 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.3

Metal injection molding (MIM) is a versatile technique for economically manufacturing various metal parts with complicated shapes and excellent properties. The objective of this study was to clarify the effects of powder type (water-atomized and gas-atomized powders) and various heat treatments (sintering, solutioning, H900, and H1100) on the microstructures, mechanical properties, and fracture behaviors of MIM 17- 4PH stainless steels. The results showed that better mechanical properties of MIM 17-4PH can be achieved with gas-atomized powder than with water-atomized powder due mainly to the lower silicon and oxygen contents and fewer SiO2 inclusions in the steels. The presence of 10 vol% δ ferrite does not impair the UTS or elongation of MIM 17-4PH stainless steels. The δ ferrite did not fracture, even though the neighboring martensitic matrix was severely cracked. Moreover, H900 treatment produces the highest hardness and UTS, along with moderate elongation. H1100 treatment produces the best elongation, along with moderate hardness and UTS.

DECOMPOSITIONS OF IDEALS IN BCI-ALGEBRAS

Wei, Shi-Ming,Jun, Young-Bae Korean Mathematical Society 1994 대한수학회논문집 Vol.9 No.2

In 1966, Iseki [4] introduced the notion of BCI-algebras which is a generalization of BCK-algebras. The ideal theory plays an important role in studying BCK/BCI-algebras. In this paper we study decompositions of ideals in BCI-algebras, and give a characterization of closed ideals. Also we define ignorable ideals in BCI-algebras, and investigates its properties.(omitted)

Experimental Study on Sustained-release 5-Fluorouracil Implantation in Canine Peritoneum and Para-aortic Abdominalis

Wei, Guo,Nie, Ming-Ming,Shen, Xiao-Jun,Xue, Xu-Chao,Ma, Li-Ye,Du, Cheng-Hui,Wang, Shi-Liang,Bi, Jian-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Objective: To observe local and systemic toxicity after sustained-release 5-fluorouracil (5-Fu) implantation in canine peritoneum and para-aortic abdominalis and the changes of drug concentration in the local implanted tissue with time. Methods: 300 mg sustained-release 5-Fu was implanted into canine peritoneum and para-aorta abdominalis. Samples were taken 3, 5, 7 and 10 days after implantation for assessment of changes and systemic reactions. High performance liquid chromatography was applied to detect the drug concentrations of peritoneal tissue at different distances from the implanted site, lymphatic tissue of para-aortic abdominalis, peripheral blood and portal venous blood. Results: 10 days after implantation, the drug concentrations in the peritoneum, lymphatic tissue and portal vein remained relatively high within 5 cm of the implanted site. There appeared inflammatory reaction in the local implanted tissue, but no visible pathological changes such as cell degeneration and necrosis, and systemic reaction like anorexia, nausea, vomiting and fever. Conclusions: Sustained-release 5-Fu implantation in canine peritoneum and para-aortic abdominalis can maintain a relatively high tumour-inhibiting concentration for a longer time in the local implanted area and portal vein, and has mild local and systemic reactions. Besides, it is safe and effective to prevent or treat recurrence of gastrointestinal tumours and liver metastasis.

AFP, PIVKA-II, AFP-L3 alone and in combination for early detection of hepatocellular carcinoma in nonalcoholic fatty liver disease: A multicenter analysis

Ming-Cheng GUAN,Wei OUYANG,Si-Yu LIU,Li-Yang SUN,Wei-Yue CHEN,Xiang-Min TONG,Hong ZHU,Tian YANG 한국간담췌외과학회 2022 Annals of hepato-biliary-pancreatic surgery Vol.26 No.-

WEAKLY POSITIVE IMPLICATIVE BCI-ALGEBRAS

Wei, Shi-Ming,Jun, Young-Bae Korean Mathematical Society 1995 대한수학회논문집 Vol.10 No.4

We introduce the concept of weakly positive implicative ideals in BCI-algebras and give some characterization of weakly positive implicative BCI-algebras and weakly positive implicative ideals.

Increased Expression of EMMPRIN and VEGF in the Rat Brain after Gamma Irradiation

Ming Wei,Hong Li,Huiling Huang,Desheng Xu,Dashi Zhi,Dong Liu,Yipei Zhang 대한의학회 2012 Journal of Korean medical science Vol.27 No.3

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot,immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.