Novel Water-Air Circulation Quenching Process for AISI 4140 Steel

Liyun Zheng,Dawei Zheng1,Lixin Zhao,Lihui Wang,Kai Zhang 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.6

AISI 4140 steel is usually used after quenching and tempering. During the heat treatment process in industry production, there are some problems, such as quenching cracks, related to water-cooling and low hardness due to oil quenching. A water-air circulation quenching process can solve the problems of quenching cracks with water and the high cost quenching with oil, which is flammable, unsafe and not enough to obtain the required hardness. The control of the water-cooling and air-cooling time is a key factor in the process. This paper focuses on the quenching temperature, water-air cycle time and cycle index to prevent cracking for AISI 4140 steel. The optimum heat treatment parameters to achieve a good match of the strength and toughness of AISI 4140 steel were obtained by repeated adjustment of the water-air circulation quenching process parameters. The tensile strength, Charpy impact energy at -10 °C and hardness of the heat treated AISI 4140 steel after quenching and tempering were approximately 1098 MPa, 67.5 J and 316 HB, respectively.

알록산 투여로 유발된 실험적 당뇨병에 대한 사인추출물의 치료 효과

노혜원,이지나,구본선,조정임,박진우,김형로 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.26 No.2

연구배경:사인추출물이 알록산에 의한 당뇨 유발을 억제하는 효과가 있음을 이미 확인하였던 바 사인 추출물이 췌장 베타세포가 손상되어 유발된 당뇨병의 치료에 사용할 수 있는지의 가능성을 알아보았다. 방법:실험적 당뇨는 알록산(60㎎/㎏)을 생쥐 꼬리 정맥을 통해 주사하여 유발시켰다. 당뇨에 미치는 사인추출물의 영향을 관찰하기 위하여 사인추출물의 영향을 관찰하기 위하여 사인추출물(2.5㎎/생쥐)을 하루에 두 번 생쥐 복강 내로 투여하였다. 당뇨에 미치는 사인추출물의 영향을 관찰하기 위하여 생쥐에 사인추출물을 처리한 다음 혈당 및 혈청 인슐린 농도 변화 및 조직학적인 소견으로 확인하였다. 결과:생쥐에 알록산을 투여하면 췌장 베타세포가 파괴되어 고혈당 및 hypoinsulinemia가 유발되었다. 사인추출물을 알록산 투여 전 2일 동안 전처리하면 알록산에 의한 고혈당이 완전히 억제되었다. 뿐만 아니라 알록산에 의해 유발된 췌장 베타세포의 손상은 사인추출물의 투여로 현저히 개선되어 혈당 및 혈청 인슐린 농도가 거의 정상 수준으로 회복되었다. 알록산을 투여한 생쥐의 췌장 소도는 정상군에 비해 수가 현저히 감소되었을 뿐 아니라 남아있는 소도의 크기도 현저히 줄어들어 있었으나, 사인추출물을 처리하면 모두 회복되어 정상군과 유사한 양상을 보였다. 결론:사인추출물은 알록산에 의해 유발되는 당뇨병을 억제하는 방어 작용 뿐만 아니라, 알록산 투여로 이미 손상된 췌장 베타세포를 개선시킬 수 있는 치료 효과작용도 가지고 있음을 확인하였다. 이를 토대로 사인의 당뇨 개선 기전을 규명하면 당뇨병 치료제로서 이용할 수 있으리라 사료된다. Background : During the screening of natural products for potential antidiabetogenic components, a strong protective effect of Amomum xanthoides extract on alloxan-induced β-cell damage and in a mice diabetic model. In this study, the therapeutic effect of Amomum xanthoides extract was investigated after induction of diabetes by alloxan. Methods : Experimental diabetes was induced by the injection of alloxan(60mg/kg) to the mouse via the tail vein. To examine the effect the of Amomum xanthoides extract on diabetes, Amomum xanthoides extract (2.5mg/mouse) was admini-strated intraperitoneally. The effect of the Amomum xanthoides extract on alloxan-induced diabetes was observed by measuring the blood glucose and serum insulin level, and a histological examination. Results : Alloxan caused hyperglycemia and hypoinsulinemia by a selectively destroying pancreatic β-cell. Pretreating the with an Amoumum xanthoides extract completely protected them from the hyperglycemia induced by alloxan. In addition, the Amomum xanthoides extract administe 3 days after the of alloxan injection significantly abolished the hyperglycemia and hypoinsulinemia induced by alloxan. The alloxan-treated mice showed a marked change of in the pancreatic islets: the number of islets was reduced and the size of the remaining islets also decreased. However these effects of alloxan were significantly recovered by a later administration of the Amomum xanthoides extract. Conclusion : The amomum xanthoides extract contains potentially effective components, which both protect and treat alloxan-induced diabetes. The identification and action mechanism of the effective components of the Amomum xanthoides extract requires further investigation and it is suggested that the Amomum xanthoides extract be used as a therapeutic drug for diabetes(J Kor Diabetes 26:126~133, 2002).

Effects of Aqueous Extract of Schizandra Chinensis Fruit on Cadmium-Induced Change of Monoamine Neurotransmitters in Rats

Zhao, Zheng Lin,Zhao, Guang Wen,Li, Li,Li, Meng Quan,Guan, Li Xin,Yang, Xu Dong,Li, Hou Zhong,Lin, Feng,Lee, Jong-Rok,Zhao, Rong Jie Korean Society of ToxicologyKorea Environmental Mu 2009 Toxicological Research Vol.26 No.1

The effects of aqueous extract of Schizandra Chinensis Fruit (AESC) on cadmium-induced changes of monoamine neurotransmitters in the different brain regions of adult rats were investigated. Male rats were received intraperitoneal (i.p.) administration of CdCl2 (0.6 mg/kg/d) for 21 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA) in striatum and serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in cortex were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Cd intoxicated rats (P < 0.05), while pretreatment with AESC (20 mg/kg/d or 60 mg/kg/d, p.o., 30 min before $CdCl_2$) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC significantly increased the reduction of glutathione contents and superoxide dismutase activities in cortex induced by $CdCl_2$. These results suggest that AESC ameliorates Cd-induced depletion of monoamine neurotransmitters in brain through its antioxidant activity.

Effects of Aqueous Extract of Schizandra Chinensis Fruit on Cadmium-Induced Change of Monoamine Neurotransmitters in Rats

Zheng Lin Zhao,Guang Wen Zhao,Li Li,Meng Quan Li,Li Xin Guan,Xu Dong Yang,Hou Zhong Li,Feng Lin,Jong Rok Lee,Rong Jie Zhao 한국독성학회 2009 Toxicological Research Vol.25 No.1

The effects of aqueous extract of Schizandra Chinensis Fruit (AESC) on cadmium-induced changes of monoamine neurotransmitters in the different brain regions of adult rats were investigated. Male rats were received intraperitoneal (i.p.) administration of CdCl₂ (0.6 ㎎/㎏/d) for 21 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA) in striatum and serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in cortex were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Cd intoxicated rats (P < 0.05), while pretreatment with AESC (20 ㎎/㎏/d or 60 mg/kg/d, p.o., 30 min before CdCl₂) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC significantly increased the reduction of glutathione contents and superoxide dismutase activities in cortex induced by CdCl₂. These results suggest that AESC ameliorates Cd-induced depletion of monoamine neurotransmitters in brain through its antioxidant activity.

Effects of Aqueous Extract of Schizandrae Fructus on Lead-Induced Change of Monoamine Neurotransmitters in Hippocampus

Zhao, Rong Jie,Zhao, Zheng Lin,Zhao, Xiu Feng,Zhao, Guang Wen,Li, Meng Quan,Wu, Yi Yan,Li, Jing Qiu,Guan, Li Xin,Kim, Sang-Chan The Korean Medicine Society for the Herbal Formula 2009 大韓韓醫學方劑學會誌 Vol.17 No.2

The effects of aqueous extract of Schizandrae Fructus (AESC) on lead (Pb)-induced changes of monoamine neurotransmitters in the hippocampus (HIP) of adult rats were investigated. Male Sprague-Dawley rats were received intraperitoneal (i.p.) administration of Pb acetate (5 mg/kg/d) for 28 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in HIP were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Pb treated rats (P < 0.05), while pretreatment with AESC (100 mg/kg/d or 300 mg/kg/d, p.o., 2 h before Pb) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC (300 mg/kg/d) significantly increased the reduction of glutathione contents and superoxide dismutase activities in HIP induced by chronic Pb. These results suggest that AESC ameliorates Pb-induced depletion of monoamine neurotransmitters in HIP through its antioxidant activity.

Radiotherapy combined with immunotherapy could improve the immune infiltration of melanoma in mice and enhance the abscopal effect

Yufeng Zheng(Yufeng Zheng),Xue Liu(Xue Liu),Na Li(Na Li),Aimei Zhao(Aimei Zhao),Zhiqiang Sun(Zhiqiang Sun),Meihua Wang(Meihua Wang),Judong Luo(Judong Luo) 대한방사선종양학회 2023 Radiation Oncology Journal Vol.41 No.2

Purpose: To analyze the gene mutation, immune infiltration and tumor growth of primary tumor and distant tumor under different treatment modes. Materials and Methods: Twenty B16 murine melanoma cells were injected subcutaneously into the of both sides of the thigh, simulating a primary tumor and a secondary tumor impacted by the abscopal effect, respectively. They were divided into blank control group, immunotherapy group, radiotherapy group, and radiotherapy combined immunotherapy group. During this period, tumor volume was measured, and RNA sequencing was performed on tumor samples after the test. R software was used to analyze differentially expressed genes, functional enrichment, and immune infiltration. Results: We found that any treatment mode could cause changes in differentially expressed genes, especially the combination treatment. The different therapeutic effects might be caused by gene expression. In addition, the proportions of infiltrating immune cells in the irradiated and abscopal tumors were different. In the combination treatment group, T-cell infiltration in the irradiated site was the most obvious. In the immunotherapy group, CD8+ T-cell infiltration in the abscopal tumor site was obvious, but immunotherapy alone might have a poor prognosis. Whether the irradiated or abscopal tumor was evaluated, radiotherapy combined with anti-programmed cell death protein 1 (anti-PD-1) therapy produced the most obvious tumor control and might have a positive impact on prognosis. Conclusion: Combination therapy not only improves the immune microenvironment but may also have a positive impact on prognosis.

Long Noncoding RNA MALAT1 Regulates Hepatocellular Carcinoma Growth Under Hypoxia via Sponging MicroRNA-200a

Zheng-Bin Zhao,Fei Chen,Xiao-Fang Bai 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.8

Purpose: Hepatocellular carcinoma (HCC) is a common cancer worldwide. Metastasis-associated lung adenocarcinoma transcript1 (MALAT1), a long noncoding RNA (lncRNA), has been reported to be aberrantly expressed in hypoxic cancer cells. MALAT1 playsa significant role in many malignancies, including HCC. The aim of this study was to explore the role of MALAT1 in hypoxic HCCcells and its underlying regulatory mechanism. Materials and Methods: Quantitative reverse transcription PCR (qRT-PCR) assay was performed to detect the mRNA levels ofMALAT1 and microRNA-200a (miR-200a) in HCC cells. Cell invasion and migration ability were evaluated by Transwell assay. Starbasev2.0 and luciferase reporter assay were employed to identify the association between MALAT1 and miR-200a. Cell proliferationand apoptosis were measured by MTT assay and flow cytometry, respectively. Results: MALAT1 levels were significantly upregulated in HCC cells under hypoxia. Hypoxia promoted proliferation, migration,and invasion, and blocked apoptosis in Hep3B cells, which were weakened by knockdown of MALAT1. Starbase v2.0 showed thatMALAT1 and miR-200a have a complementarity region, and luciferase reporter assay verified that MALAT1 interacted with miR-200a in Hep3B cells. Moreover, MALAT1 negatively regulated the expression of miR-200a. miR-200a levels were dramatically downregulatedin HCC cells under hypoxia. Upregulation of miR-200a inhibited proliferation, migration, and invasion, and inducedapoptosis in Hep3B cells under hypoxia. Interestingly, downregulation of miR-200a partially reversed the tumor-suppressive effectof knockdown of MALAT1 on Hep3B cells in hypoxic condition. Conclusion: LncRNA MALAT1 was involved in proliferation, migration, invasion, and apoptosis by interacting with miR-200a inhypoxic Hep3B cells, revealing a new mechanism of MALAT1 involved in hypoxic HCC progression.

Optimization of Reference Genes for Normalization of the Quantitative Polymerase Chain Reaction in Tissue Samples of Gastric Cancer

Zhao, Lian-Mei,Zheng, Zhao-Xu,Zhao, Xiwa,Shi, Juan,Bi, Jian-Jun,Pei, Wei,Feng, Qiang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

For an exact comparison of mRNA transcription in different samples or tissues with real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), it is crucial to select a suitable internal reference gene. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB) have been frequently considered as house-keeping genes to normalize for changes in specific gene expression. However, it has been reported that these genes are unsuitable references in some cases, because their transcription is significantly variable under particular experimental conditions and among tissues. The present study was aimed to investigate which reference genes are most suitable for the study of gastric cancer tissues using qRT-PCR. 50 pairs of gastric cancer and corresponding peritumoral tissues were obtained from patients with gastric cancer. Absolute qRT-PCR was employed to detect the expression of GAPDH, ACTB, RPII and 18sRNA in the gastric cancer samples. Comparing gastric cancer with corresponding peritumoral tissues, GAPDH, ACTB and RPII were obviously upregulated 6.49, 5.0 and 3.68 fold, respectively. Yet 18sRNA had no obvious expression change in gastric cancer tissues and the corresponding peritumoral tissues. The expression of GAPDH, ${\beta}$-actin, RPII and 18sRNA showed no obvious changes in normal gastric epithelial cells compared with gastric cancer cell lines. The carcinoembryonic antigen (CEA), a widely used clinical tumor marker, was used as a validation gene. Only when 18sRNA was used as the normalizing gene was CEA obviously elevated in gastric cancer tissues compared with peritumoral tissues. Our data show that 18sRNA is stably expressed in gastric cancer samples and corresponding peritumoral tissues. These observations confirm that there is no universal reference gene and underline the importance of specific optimization of potential reference genes for any experimental condition.

Amygdaloid Corticotropin-releasing Factor is Involved in the Anxiolytic Effect of Acupuncture during Ethanol Withdrawal in Rats

Zheng Lin Zhao,XiuDong Jin,Yi Yan Wu,Xu Dong Yang,YanJi Xu,James ZhongJian Jiang,김상찬,이봉효,양재하,조용걸 사단법인약침학회 2013 Journal of Acupuncture & Meridian Studies Vol.6 No.5

In a previous study, acupuncture at acupoint HT7 attenuated ethanol withdrawal-induced anxiety-like behavior in rats by normalizing amygdaloid catecholamines. In the present study, the involvement of amygdaloid corticotropin-releasing factor (CRF) in the anxiolytic effect of acupuncture was investigated during ethanol withdrawal. Rats were intraperitoneally treated with 3 g /kg/day of ethanol for 28 days, and the CRF mRNA levels in the central nucleus of the amygdala (CEA) were measured by using a RT-PCR analysis 72 hours after the last dose of ethanol. During ethanol withdrawal, the rats were bilaterally treated with acupuncture at acupoints HT7, PC6 or at a non-acupoint (Tail) for one min/day for three days. Also, rats were bilaterally injected with CRF into the CEA five minutes after the third acupuncture treatment , after which followed by the elevated-plus maze (EPM) test and the plasma corticosterone radioimmunoassay (RIA) were administered. The RT-PCR analysis showed a significant increase in the amygdaloid CRF mRNA levels in the ethanol-withdrawn rats compared with both the saline-treated rats and the rats treated with acupuncture at HT7, but neither acupuncture at PC6 nor acupuncture at a non-acupoint significantly inhibited the increased mRNA expression. The EPM test and the RIA also showed that the post-acupuncture infusion of CRF greatly reduced the anxiolytic effect of acupuncture at HT7. These results suggest that during ethanol withdrawal, the anxiolytic effect of acupuncture may be mediated through the modulation of amydaloid CRF during ethanol withdrawal.

Theoretical Studies on Nitramine Explosives with -NH₂ and -F Groups

Zhao, Guo Zheng,Lu, Ming Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.6

The nitramine explosives with $-NH_2$ and -F groups were optimized to obtain their molecular geometries and electronic structures at DFT-B3LYP/6-31+G(d) level. The theoretical molecular density (${\rho}$), heat of formation (HOF), detonation velocity ($D$) and detonation pressure ($P$), estimated using Kamlet-Jacobs equations, showed that the detonation properties of these compounds were excellent. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties were evaluated, which were respectively related with the temperature. The simulation results reveal that 1,3,5,7-tetranitro-1,3,5,7-tetrazocan-2-amine (molecule B1) performs similarly to the famous explosive HMX, and 2-fluoro-1,3,5-trinitro-1,3,5-triazinane (molecule C1) and 2-fluoro-1,3,5,7-tetranitro-1,3,5,7-tetrazocane (molecule D1) outperform HMX. According to the quantitative standard of energetics and stability as an HEDC (high energy density compound), molecules C1 and D1 essentially satisfy this requirement. These results provide basic information for molecular design of novel high energetic density compounds.