Effect of Different Cooling Rates in High Rheological Rate Forming Process on Mechanical Properties of Zr57Cu20Al10Ni8Ag5 Bulk Metallic Glass

Xiao‑Bo Mei,Bao‑Chuan Liu,Wei Jiang,Quan Xu,Qi‑Dong Zhang,Yu‑Bai Ma,Fang‑Qiu Zu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

The influence of cooling rates on the mechanical properties of a Zr-based bulk metallic glass prepared with high rheologicalrate forming (HRRF) was investigated and compared with traditional suction cast methods. Amorphous samples of Zr57Cu-20Ni8Al10Ag5 were prepared in copper molds with different sizes in order to obtain different cooling rates for both HRRFand traditional cast methods. These specimens were subjected to compression experiments, including microhardness testing,X-ray diffraction testing and differential scanning calorimetry analysis. The results indicate that the plasticity of the samplesformed by HRRF are higher than that of the as-cast ones at the same cooling rates, while the microhardness manifests theopposite principle. As the cooling rate increases further, the difference in plasticity further increases between two methods,indicating that the plasticity of metallic glasses is more sensitive to cooling rates during the HRRF process. At the core ofthis phenomenon is the fact that HRRF methods can introduce more free volume into glasses than traditional cast methodswith an elevated cooling rate are able to.

The treatment effect of novel hGHRH homodimer to male infertility hamster

Xu-Dong Zhang,Xiao-Yuan Guo,Jing-Xuan Tang,Lin-Na Yue,Juan-Hui Zhang,Tao Liu,Yu-Xia Dong,Song-Shan Tang 대한생리학회-대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.6

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in reproduction. To study the treatment effect of Grin (a novel hGHRH homodimer), the infertility models of 85 male Chinese hamsters were established by intraperitoneally injecting 20 mg/kg of cyclophosphamide once in a week for 5 weeks and the treatment with Grin or human menopausal gonadotropin (hMG) as positive control was evaluated by performing a 3-week mating experiment. 2-8 mg/kg of Grin and 200 U/kg of hMG showed similar effect and different pathological characteristics. Compared to the single cyclophosphamide group (0%), the pregnancy rates (H-, M-, L-Grin 26.7, 30.8, 31.3%, and hMG 31.3%) showed significant difference, but there was no difference between the hMG and Grin groups. The single cyclophosphamide group presented loose tubules with pathologic vacuoles and significant TUNEL positive cells. Grin induced less weight of body or testis, compactly aligned tubules with little intra-lumens, whereas hMG caused more weight of body or testis, enlarging tubules with annular clearance. Grin presented a dose-dependent manner or cell differentiation-dependentincrease in testicular GHRH receptor, and did not impact the levels of blood and testicular GH, testosterone. Grin promotes fertility by proliferating and differentiating primitive cells through up-regulating testicular GHRH receptor without triggering GH secretion, which might solve the etiology of oligoasthenozoospermia.

Statistical experimental design optimization of rhamsan gum production by Sphingomonas sp. CGMCC 6833

Xiao-Ying Xu,Shu-Hao Dong,Sha Li,Xiao-Ye Chen,Ding Wu,Hong Xu 한국미생물학회 2015 The journal of microbiology Vol.53 No.4

Rhamsan gum is a type of water-soluble exopolysaccharideproduced by species of Sphingomonas bacteria. The optimalfermentation medium for rhamsan gum production bySphingomonas sp. CGMCC 6833 was explored definition. Single-factor experiments indicate that glucose, soybean meal,K2HPO4 and MnSO4 compose the optimal medium alongwith and initial pH 7.5. To discover ideal cultural conditionsfor rhamsan gum production in a shake flask culture, responsesurface methodology was employed, from which thefollowing optimal ratio was derived: 5.38 g/L soybean meal,5.71 g/L K2HPO4 and 0.32 g/L MnSO4. Under ideal fermentationrhamsan gum yield reached 19.58 g/L ± 1.23 g/L,42.09% higher than that of the initial medium (13.78 g/L ±1.38 g/L). Optimizing the fermentation medium results inenhanced rhamsan gum production.

Autophagy in Tumorigenesis and Cancer Treatment

Xu, Dong-Wei,Zhang, Guan-Qing,Wang, Zong-Wei,Xu, Xiao-Yin,Liu, Tong-Xiang Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Autophagy is a self-digestion process, wrapping cytoplasmic proteins or organelles to form vesicles for degradation in lysosomes. The process plays an important role in the maintenance of intracellular homostasis. Here we overview articles on autophagy and cancer/tumors in Pubmed and found 327 articles. Autophagy exists in many tumors and is involved in cell malignant transformation and tumor cell growth. In early phases of tumorigenesis, autophagy clears the abnormally folded proteins and dysfunctional organelles such as mitochondria. Autophagy can also inhibit cell stress responses and prevent genetic damage. When a tumor develops, autophagy helps tumor cells survive nutritional deficiencies and hypoxic conditions. Studies of autophagy in the occurrence and progression of tumors should provide new therapeutic strategies for tumors.

The treatment effect of novel hGHRH homodimer to male infertility hamster

Zhang, Xu-Dong,Guo, Xiao-Yuan,Tang, Jing-Xuan,Yue, Lin-Na,Zhang, Juan-Hui,Liu, Tao,Dong, Yu-Xia,Tang, Song-Shan The Korean Society of Pharmacology 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.6

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in reproduction. To study the treatment effect of Grin (a novel hGHRH homodimer), the infertility models of 85 male Chinese hamsters were established by intraperitoneally injecting 20 mg/kg of cyclophosphamide once in a week for 5 weeks and the treatment with Grin or human menopausal gonadotropin (hMG) as positive control was evaluated by performing a 3-week mating experiment. 2-8 mg/kg of Grin and 200 U/kg of hMG showed similar effect and different pathological characteristics. Compared to the single cyclophosphamide group (0%), the pregnancy rates (H-, M-, L-Grin 26.7, 30.8, 31.3%, and hMG 31.3%) showed significant difference, but there was no difference between the hMG and Grin groups. The single cyclophosphamide group presented loose tubules with pathologic vacuoles and significant TUNEL positive cells. Grin induced less weight of body or testis, compactly aligned tubules with little intra-lumens, whereas hMG caused more weight of body or testis, enlarging tubules with annular clearance. Grin presented a dose-dependent manner or cell differentiation-dependentincrease in testicular GHRH receptor, and did not impact the levels of blood and testicular GH, testosterone. Grin promotes fertility by proliferating and differentiating primitive cells through up-regulating testicular GHRH receptor without triggering GH secretion, which might solve the etiology of oligoasthenozoospermia.

Erratum to: The treatment effect of novel hGHRH homodimer to male infertility hamster

Zhang, Xu-Dong,Guo, Xiao-Yuan,Tang, Jing-Xuan,Yue, Lin-Na,Zhang, Juan-Hui,Liu, Tao,Dong, Yu-Xia,Tang, Song-Shan The Korean Society of Pharmacology 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.1

8q24 rs4242382 Polymorphism is a Risk Factor for Prostate Cancer among Multi-Ethnic Populations: Evidence from Clinical Detection in China and a Meta-analysis

Zhao, Cheng-Xiao,Liu, Ming,Xu, Yong,Yang, Kuo,Wei, Dong,Shi, Xiao-Hong,Yang, Fan,Zhang, Yao-Guang,Wang, Xin,Liang, Si-Ying,Zhao, Fan,Zhang, Yu-Rong,Wang, Na-Na,Chen, Xin,Sun, Liang,Zhu, Xiao-Quan,Yuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: Evidence supporting an association between the 8q24 rs4242382-A polymorphism and prostate cancer (PCa) risk has been reported in North American and Europe populations, though data from Asian populations remain limited. We therefore investigated this association by clinical detection in China, and meta-analysis in Asian, Caucasian and African-American populations. Materials and Methods: Blood samples and clinical information were collected from ethnically Chinese men from Northern China with histologically-confirmed PCa (n=335) and from age-matched normal controls (n=347). The 8q24 (rs4242382) gene polymorphism was genotyped by polymerase chain reaction-high-resolution melting analysis. We initially analyzed the associations between the risk allele and PCa and clinical covariates. A meta-analysis was then performed using genotyping data from a total of 1,793 PCa cases and 1,864 controls from our study and previously published studies in American and European populations, to determine the association between PCa and risk genotype. Results: The incidence of the risk allele was higher in PCa cases than controls (0.222 vs 0.140, $P=7.3{\times}10^{-5}$), suggesting that the 8q24 rs4242382-A polymorphism was associated with PCa risk in Chinese men. The genotypes in subjects were in accordance with a dominant genetic model (ORadj=2.03, 95%CI: 1.42-2.91, $Padj=1.1{\times}10^{-4}$). Presence of the risk allele rs4242382-A at 8q24 was also associated with clinical covariates including age at diagnosis ${\geq}65$ years, prostate specific antigen >10 ng/ml, Gleason score <8, tumor stage and aggressive PCa, compared with the non-risk genotype ($P=4.6{\times}10^{-5}-3.0{\times}10^{-2}$). Meta-analysis confirmed the association between 8q24 rs4242382-A polymorphism and PCa risk (OR=1.62, 95%CI: 1.39-1.88, $P=1.0{\times}10^{-5}$) across Asian, Caucasian and African American populations. Conclusions: The replicated data suggest that the 8q24 rs4242382-A variation might be associated with increased PCa susceptibility in Asian, Caucasian and African American populations. These results imply that this polymorphism may be a useful risk biomarker for PCa in multi-ethnic populations.

Ordering connected graphs by their Kirchhoff indices

Xu, Kexiang,Das, Kinkar Ch.,Zhang, Xiao-Dong Informa UK (TaylorFrancis) 2016 International journal of computer mathematics Vol.93 No.10

<P>The Kirchhoff index Kf(G) of a graph G is the sum of resistance distances between all unordered pairs of vertices, which was introduced by Klein and Randi ' c. In this paper, we characterize all extremal graphs with respect to Kirchhoff index among all graphs obtained by deleting p edges from a complete graph K-n with p <= left perpendicular n/2 right perpendicular and obtain a sharp upper bound on the Kirchhoff index of these graphs. In addition, all the graphs with the first to ninth maximal Kirchhoff indices are completely determined among all connected graphs of order n > 27.</P>

Effect of SiCp size on wear behavior of SiCp/Cu matrix composite

Xiao-Jing Xu,Seock-Sam Kim,Young-Jun Jang,Dong-Woo Shin 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.38 No.-

SiC particulate reinforced copper (SiCp/Cu) matrix composites were fabricated by powder metallurgy, using SiCp of various grit sizes (a nominal diameter of 30㎚, 130㎚ and 14㎛, respectively) and micron Cu as the raw materials. The resulting composites specimens were hot extruded to get rid of the possible void and increase compactness. The friction and wear behaviors of various SiCp reinforced SiCp/Cu matrix composites sliding against a AISI5140 steel under the lubrication of 20<SUP>#</SUP> machinery oil were investigated on an MM-200 friction and wear tester in a block-on-ring configuration, using a pure copper fabricated by the above same manufacture method and a commercial bronze alloy (6.5-0.4 bronze) as a control. The microstructures and worn surface morphologies of the SiCp/Cu composites and the counterpart AISI5140 steel was observed on a scanning electron microscopy, while the elemental compositions on the worn surfaces of various SiCp/Cu matrix composites were determined by means of energy dispersive spectroscopy. As the results, the incorporation of the SiCp of various grit sizes contributed to increase the wear-resistance of the Cu-matrix materials considerably. The SiCp/Cu matrix composite reinforced with the SiCp of larger grit size showed better wear-resistance than that reinforced with the SiCp of smaller grit sizes. However, the SiCp/Cu matrix composite reinforced with larger SiCp lead to a more severe scuffing to the counterpart steel surface, which was characterized by more severe transfer and adhesion of the counterpart steel wear debris onto the SiCp/Cu matrix composites worn surface. Therefore, in terms of the comprehensive wear-resistance of the frictional pair, it was suggested to select the SiCp/Cu matrix composite reinforced with the SiCp size of 130㎚ to mate the AISI5140 steel.

Tim-3 Expression by Peripheral Natural Killer Cells and Natural Killer T Cells Increases in Patients with Lung Cancer - Reduction after Surgical Resection

Xu, Li-Yun,Chen, Dong-Dong,He, Jian-Ying,Lu, Chang-Chang,Liu, Xiao-Guang,Le, Han-Bo,Wang, Chao-Ye,Zhang, Yong-Kui Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: The purpose of this study was to investigate Tim-3 expression on peripheral CD3-CD56+ natural killer (NK) cells and CD3+CD56+ natural killer T (NKT) cells in lung cancer patients. Materials and Methods: We analyzed Tim-3+CD3-CD56+ cells, Tim-3+CD3-$CD56^{dim}$ cells, Tim-3+CD3-$CD56^{bright}$ cells, and Tim-3+CD3+CD56+ cells in fresh peripheral blood from 79 lung cancer cases preoperatively and 53 healthy controls by flow cytometry. Postoperative blood samples were also analyzed from 21 members of the lung cancer patient cohort. Results: It was showed that expression of Tim-3 was significantly increased on CD3-CD56+ cells, CD3-$CD56^{dim}$ cells and CD3+CD56+ cells in lung cancer patients as compared to healthy controls (p=0.03, p=0.03 and p=0.04, respectively). When analyzing Tim-3 expression with cancer progression, results revealed more elevated Tim-3 expression in CD3-CD56+ cells, CD3-$CD56^{dim}$ cells and CD3+CD56+ cells in cases with advanced stages (III/IV) than those with stage I and II (p=0.02, p=0.04 and p=0.01, respectively). In addition, Tim-3 expression was significantly reduced on after surgical resection of the primary tumor (p<0.01). Conclusions: Tim-3 expression in natural killer cells from fresh peripheral blood may provide a useful indicator of disease progression of lung cancer. Furthermore, it was indicated that Tim-3 might be as a therapeutic target.