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The interface characteristics, bending and impact behavior, as well as fracture characteristics of stainless steel clad plates fabricated by vacuum hot rolling at different rolling temperatures of 1100°C, 1200°C and 1300°C are investigated in detail. The interface bonding strength is gradually increased with the increasing rolling temperature due to the sufficient diffusion behavior of alloy element. The bending toughness and impact toughness are gradually decreased, while the bending strength increase with the increase of the rolling temperature, which is attributed to mechanisms of matrix softening and interface strengthening at high rolling temperature. Due to the weak interface at 1100°C, the bending and impact crack propagation path was displaced by delamination cracks, which in turn lead to reduction in stress intensity of the main crack, playing an effective role in toughening the stainless steel clad plates. Moreover, the impact fracture morphologies of clad plates show a typical ductile-brittle transition phenomenon, which is attributed to the matrix softening behavior with the increasing rolling temperature. [ABSTRACT FROM AUTHOR]

This work aims to study the microstructure and mechanical properties of stainless steel/carbon steel clad plate joints with three welding types: welding without transition layer, welding with transition layer using tungsten inert gas arc welding and shielded metal arc welding, respectively. Both of transition layer-weld metals contain ferrite + austenite phases obtained by different solidification modes. The brittle martensite zone is formed in the stainless steel weld metal without the transition layer because of the excessive diffusion of Cr, Ni elements. The clad plate joints with transition layer welded by shielded metal arc welding achieved the best welding quality without excessive alloy element dilution or formation of brittle phase, which reveals a perfect welding joint without obvious hardness gradient and obtains outstanding mechanical properties. [ABSTRACT FROM AUTHOR]

MnCuNiFe damping alloy was prepared to characterise the dynamic mechanical behaviour under varied frequency by employing dynamic mechanical analyzer, optical microscopy and X-ray diffraction. The relationship of characteristic temperatures is disentangled by antiferromagnetic transition (AFT), the strain glass transition and reverse martensitic transformation. It is reported that although only f.c.c. (γ) phase exists in the alloy under solution state, twins are induced by AFT. The aged alloy shows an elevated damping capacity while the maximum internal friction decreases from 0.1 to 10 Hz and then increases to 150 Hz, demonstrating the system resonant frequency of about 10 Hz under the vibration mode of double cantilever beam. [ABSTRACT FROM AUTHOR]

This paper investigated the microstructure and mechanical properties of Q235/304 stainless steel clad plate welding seam produced by hybrid welding of tungsten inert gas welding (TIG) and metal active gas arc welding (MAG). The results showed that the dual phases containing ferrite and austenite appeared in the stainless steel covering welding (SSCW), while the partial martensite phases appeared in the carbon steel backing welding (CSBW), which is attributed to the dilution behavior of Ni and Cr elements from stainless steel to the Q235 steel results into the movement of the CCT curve to the right side and the decrease of critical martensite formation cooling rate. The CSBW possesses the highest microhardness value in the weld metal due to the existence of the martensite zone. The impact tests were carried out and the results showed that the Charpy absorbed energy of weldments (81 J) is almost equal to that of base clad plate (83 J). The SSCW layer possesses the ductile fracture characteristics accompanying many dimples. However, in the CSBW layer, some cleavage fracture characteristics are presented in the radiation zone while many dimples are located in the fibrous zone, revealing a complex combination of brittle and ductile fracture behavior, which is due to the existence of martensite zone, different stress states and crack propagation velocity. Hybrid (TIG, MAG) welding is suitable for welding stainless steel clad plate; The martensite formation in CSBW is related to dilution and diffusion of Cr and Ni; Partial martensite transformation can strengthen and toughen the welding seam. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the role of microRNA-212-5p (miR-212-5p) in clear cell renal cell carcinoma (ccRCC) and to explore the potential underlying mechanisms. MATERIALS AND METHODS: 32 pairs of ccRCC clinical samples were collected. Renal ccRCC cells (786-O) and embryonic kidney cells (293T) were cultured in vitro. The ability of cell proliferation was detected by 3-(4,5)-dimethylthiazol(- z-y1)-3,5-diphenyl tetrazolium bromide (MTT) assay. Transwell migration assay was used to detect the abilities of cell invasion and migration. The relative protein and mRNA expressions of miR-212-5p were detected by Western blot and quantitative Real-time polymerase chain reaction (qRT-PCR) analysis, respectively. Furthermore, bioinformatics online sites and luciferase reporter gene assay were performed to predict and verify the potential targets of miR-212-5p, respectively. RESULTS: The expression level of miR-212-5p in ccRCC tissues and cell lines was significantly inhibited. Bioinformatics online sites and luciferase reporter gene assay confirmed that T-box transcription factor TBX15 (TBX15) was the potential target gene of miR-212-5p. In vitro experiments demonstrated that the proliferation, cell cycle, cell invasion and migration of ccRCC cells were obviously restricted after up-regulation of miR-212-5p. However, the above functional effects were significantly abolished in ccRCC cells after co-transfection with miR-212-5p mimics and LV-TBX15. CONCLUSIONS: MiR-212-5p acted as a tumor suppressor gene in ccRCC. Through targeting TBX15, miR-212-5p significantly inhibited the malignant behavior of ccRCC cells. Our findings revealed that miR-212-5p/TBX15 axis might be a potential therapeutic target for the treatment of ccRCC. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Long noncoding RNAs (lncRNAs) have been reported to be vital in tumor progression. Hepatocellular carcinoma (HCC) is a common type of fatal primary liver cancers worldwide. This study aims to determine whether lncRNA SNHG7 (small nucleolar RNA host gene 7) functions in the metastasis of HCC. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was conducted to detect the SNHG7 expression in HCC cells and tissue samples. Moreover, function assays were performed in vitro to identify the role of SNHG7 in metastasis of HCC cells. Western blot assay was used to explore the possible mechanism. RESULTS: SNHG7 expression was remarkably higher in HCC tissues than that in adjacent tissues. Moreover, HCC migration and invasion were suppressed after silence of SNHG7 in HCC cells. Moreover, after silence of SNHG7, RBM5 was upregulated in HCC cells. Besides, the expression of RBM5 in tumor tissues was negatively correlated to the expression of SNHG7. CONCLUSIONS: Our study suggests that SNHG7 could promote cell invasion and migration in HCC cells through downregulating RBM5, which may offer a new therapeutic intervention for HCC patients. [ABSTRACT FROM AUTHOR]

To investigate the characteristics of the bubbles trapped in liquid cross flow, air was injected into flowing water circulated in a closed loop. High speed photography was used to record bubble images instantaneously. An image-processing code was specifically developed to identify bubbles in the images and to calculate bubble parameters. Effects of the water velocity and the flow rate of the injected air on bubble patterns were investigated. The results indicate that the inclination of bubble trajectory relative to the nozzle axis is enhanced as the water velocity rises. Meanwhile, bubble size varies inversely with the water velocity. The bubble profile tends to be rounded as the water velocity increases. Fluctuations of the bubble velocity are intensified as the water velocity decreases. As the balance between the external forces exerted on the bubble is reached, an approximately linear relationship between the velocities of the bubble and the water is manifested. For a given equivalent bubble diameter, the bubble terminal velocity is higher than that associated with quiescent water. At small Eötvös number, the consistency of the bubble aspect ratio in the liquid flow and quiescent water is revealed. The range of Eötvös number is extended considerably due to the flowing water. Values of Weber number are accumulated in a range within which high bubble aspect ratio is associated with relatively high water velocity. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To examine the expression level of microRNA-485-5p (miRNA-485-5p) in acute myeloid leukemia (AML) and its biological function in regulating the proliferative ability of AML through targeting SALL4. PATIENTS AND METHODS: Serum level of miRNA-485-5p in AML patients and healthy controls was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). MiRNA-485-5p level in AML cell lines was detected by qRT-PCR as well. Proliferative and apoptotic changes in AML5 and U937 cells overexpressing miRNA-485-5p were assessed. Subsequently, the regulatory effect of miRNA-485-5p on SALL4 level was evaluated. Rescue experiments were conducted to uncover the role of miRNA-485-5p/SALL4 regulatory loop in regulating cellular behaviors of AML. RESULTS: Compared with healthy controls, serum level of miRNA-485-5p was lower in AML patients. MiRNA-485-5p was similarly downregulated in AML cell lines. Overexpression of miRNA-485-5p stimulated proliferation and alleviated apoptosis in AML. SALL4 level was downregulated by transfection of miRNA-485-5p mimics in AML5 and U937 cells. Overexpression of SALL4 could reverse the regulatory effect of miRNA-485-5p on proliferative and apoptotic abilities of AML. CONCLUSIONS: MiRNA-485-5p is downregulated in AML. Overexpression of miRNA-485-5p alleviates the malignant progression of AML through downregulating SALL4. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to investigate the inhibitory role of microRNA- 1299 (miR-1299) in prostate cancer, and to explore the possible underlying mechanism. PATIENTS AND METHODS: The expression of miR-1299 in 35 PCa tissues and para-carcinoma tissues, as well as PCa cell lines (PC-3) and prostatic epithelial cell line (RWPE-1), was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Then, we explored the possible targets of miR-1299 by searching online databases. NIMA-related kinase 2 (NEK2) was identified as a direct target gene of miR-1299. Subsequently, qRT-PCR, Western blot (WB), and luciferase reporter gene assay were used to further verify the correlation between miR-1299 and NEK2. To better characterize the role of miR-1299 and NEK2 in PCa, we conducted functional experiments (MTT, flow cytometry, scratch-wound, and transwell assay) by transfecting PC-3 cells with miR-1299 mimics and si- NEK2 in different groups. RESULTS: The expression level of miR-1299 in PCa tissues was significantly lower than that of para-carcinoma tissues. Meanwhile, the expression of miR-1299 in PC-3 cells was also significantly downregulated when compared with RWPE-1 cells. Subsequent qRT-PCR, WB, and luciferase reporter gene assay verified that miR- 1299 transcriptionally repressed NEK2 by interacting with the essential binding sequence in 3'- UTR. Also, functional experiments demonstrated that decreased expression of NEK2 resulting from miR-1299 up-regulation could remarkably inhibit the proliferation, invasion, and migration of PCa cells. CONCLUSIONS: Our study indicated that miR-1299 was a novel suppressor in PCa through its negative regulation of NEK2. Moreover, our findings revealed that miR-1299/NEK2 axis might be a potential therapeutic target for the treatment of PCa. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To elucidate the biological functions of long non-coding RNA (lncRNA) SNHG7 in breast cancer (BC), and its underlying mechanism in the occurrence and progression of BC. PATIENTS AND METHODS: The expression of SNHG7 in 72 pairs of BC tissues and paracancerous tissues was detected by quantitative Real-time polymerase chain reaction (qRT-PCR). Correlation between SNHG7 expressions with pathological indicators of BC patients was analyzed. Similarly, SNHG7 expression in BC cell lines was determined by qRT-PCR as well. After constructing the small inference RNA of SNHG7, cell proliferation, migration and invasion were determined by cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) and transwell assay. MicroRNA-186 expression in BC tissues and cells was accessed. Dual-luciferase reporter gene assay was conducted to verify the binding condition between SNHG7 and microRNA-186. RESULTS: SNHG7 expression was higher in BC tissues than that of paracancerous tissues. High expression of SNHG7 was positively correlated to tumor stage, lymph node metastasis and distant metastasis, whereas not correlated to age, sex and tumor location of BC. Kaplan-Meier curves revealed that higher expression of SNHG7 is correlated to the worse prognosis of BC patients. SNHG7 was highly expressed in BC cells as well. Knockdown of SNHG7 inhibited proliferative, invasive and migratory abilities of BC cells. QRT-PCR data showed that microRNA-186 is lowly expressed in BC tissues compared with that of paracancerous tissues. MicroRNA-186 was lowly expressed in BC cells as well. Both mRNA and protein levels of microRNA-186 were negatively correlated to SNHG7 in BC tissues. Finally, the dual-luciferase reporter gene assay demonstrated that SNHG7 could be directly targeted by microRNA-186. CONCLUSIONS: SNHG7 is highly expressed in BC, which is correlated to tumor stage, lymph node metastasis and distant metastasis of BC patients. SNHG7 could promote malignant progression of BC by regulating microRNA-186. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Hepatocarcinoma is a great threat to global health. MicroRNA-23a was suggested to regulate growth and apoptosis in certain cell lines. Our study was focused on growth, proliferation, and apoptosis of hepatocarcinoma cell line MHCC97H under the influence of microRNA-23a, and explored the mechanism of pro-apoptosis microRNA-23a. MATERIALS AND METHODS: MicroRNA-23a and control microRNA (scramble miRNA, for short as miRNA) were synthesized with the routine protocol. Lipofection transfection was performed in hepatocarcinoma cell line MHCC97H. 3-(4,5-dimethyl- 2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, caspase-3 activity detection, and flow cytometry were performed to examine growth, proliferation, and apoptosis of hepatocarcinoma cell line MHCC97H, respectively. Kidney inhibitor of apoptosis protein (KIAP) and small interfere RNA (siRNA) was synthesized for inhibition of KIAP. KIAP plasmid was established for activation of KIAP. Western blot was performed to examine the protein expression of KIAP and caspase protein family after transfection of KIAP siRNA or KIAP plasmid. RESULTS: Compared with miRNA transfection, microRNA-23a transfection significantly reduced the growth of MHCC97H cells, and decreased the expression of KIAP (p < 0.05). Enhanced translocation of phosphatidylserine and activation of caspase-3 were observed in microRNA-23a transfection cells. Moreover, inhibition of KIAP enhanced the pro-apoptosis effect of microRNA-23a, while activation of KIAP abrogated pro-apoptosis effect of microRNA- 23a. CONCLUSIONS: MicroRNA-23a inhibits growth and proliferation of MHCC97H cells, and induces apoptosis of MHCC97H cells via down-regulating KIAP. KIAP could be a potential therapeutic target for hepatocarcinoma treatment. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the plaque distribution and composition pattern in the left main coronary artery (LMCA) disease using intracoronary ultrasound. PATIENTS AND METHODS: Intravascular ultrasound data of 50 patients from the January 2010 to December 2015 with significant LMCA bifurcation lesions, with angiographic diameter stenosis >50%, and requiring revascularization, were evaluated. Plaque burden and percentage of necrotic core (% NC) at the minimal lumen area site and maximal % NC site were measured in different segments. The segments that were included in the study are as follows: segment 1: proximal LMCA, segment 2: left anterior descending (LAD) ostium, segment 3: left circumflex branch (LCX) ostium, segment 4: proximal LAD, segment 5: proximal LCX. According to its relationship with the bifurcation ridge, the blood vessel wall was divided into the contralateral bifurcation ridge blood vessel wall and bifurcation ridge blood vessel wall. RESULTS: Plaque burden results showed that the plaque eccentricity index of segment 2 and segment 3 was significantly higher than that of the other segments at sites of the minimal lumen area and maximal % NC with a statistically significant difference (p<0.05). Plaque eccentricity index of contralateral bifurcation ridge was significantly higher than that of the bifurcation ridge, and the difference was statistically significant (p<0.05). Analysis of plaque composition showed the fibrous tissue percentage of segment 2 and segment 3 was significantly higher than the other segments that at the sites of minimal lumen area and the maximal % NC site. The fibrous percentage of the contralateral bifurcation ridge was significantly lower than that of the bifurcation ridge. CONCLUSIONS: Intravascular ultrasound is an effective way for detecting the distribution and composition of the atherosclerotic plaque at the left main coronary artery bifurcation and is of great significance to adjuvant interventional therapy. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Long noncoding RNA SNHG7 represses the expression of RBM5 to strengthen metastasis of hepatocellular carcinoma" which appeared in the 2020 issue.