Search

Nowadays quantum-dot cellular automata (QCA) as a nanoscale transistor-less device technology have attained major attention for their prominent features. The circuits constructed by QCA technology owning remarkable decreasing in size, fast switching speed and ultra-low energy consumption. These features can be more different in varied memory structures. Random access memory (RAM) is a kind of data storage devices that allows data to be read or written it's generally volatile, and used for data that change often. Due to the significance of memory in a digital system, designing and optimization of high-speed RAM in QCA nanotechnology is a substantial subject. So, this paper presents a new structure for QCA-based RAM cell by employing the 3-input rotated majority gate (RMG). Eventually, 1 × 4 RAM is designed by exerting the individual memory cell. The functionality of the proposed design is implemented and assessed using the QCADesigner simulator. The obtained results demonstrated that the designed QCA-based RAM cell is superior to previous structures in terms of delay and cell count. [ABSTRACT FROM AUTHOR]

We developed and tested a model linking safety innovation intention with safety innovation behavior and safety performance. Participants were 407 employees of blasting, chemical, mining, and other high-risk industries in China. The results indicated that safety innovation intention was positively associated with safety performance, and safety innovation behavior played a partial mediating role in this relationship. In addition, safety climate moderated the relationship between safety innovation intention and safety innovation behavior, which mediated the interaction of safety climate and safety innovation behavior in predicting safety performance. The results support the importance of the effect of organizations' subjective intention and climate on their innovation behavior and performance in the safety domain. [ABSTRACT FROM AUTHOR]

Using the systematic method of modern ship energy efficiency management, strict control and management of ship energy consumption, energy utilization and carbon dioxide emissions will be of great significance for achieving energy conservation and emission reduction of ships and promoting the green development of shipping. On the basis of summarizing the previous research results, this paper designs a ship energy efficiency management model based on data analysis through a large number of current industry data collection, manufacturing and operation data collection, collation and analysis. The model system can monitor and collect various dynamic and static parameters in real time, and calculate the ship energy efficiency design index (EEDI) and the ship energy efficiency operation index (EEOI). Combined with the ship's own and its energy consumption information, such as range, cargo capacity, speed, host power, the system can dynamically analyze the entire production and operation process of the ship. The final simulation experiment shows the feasibility and effectiveness of this model. [ABSTRACT FROM AUTHOR]

In this study we examined the importance of entrepreneurs' internal and external social capital in the relationship between entrepreneurial self-efficacy (ESE) and firms' innovation behavior. We analyzed the data from 193 entrepreneurs in China, and the results showed that ESE positively affected firms' innovation behavior, and the entrepreneur's internal social capital played a negative mediating role in the relationship between ESE and the firm's innovation behavior. The findings both empirically support propositions of previous researchers about the negative effect of social capital in the relationship between ESE and innovation, and offer deeper insight into this. Possible explanations for our findings and future direction are also discussed. [ABSTRACT FROM AUTHOR]

We examined the relationships among entrepreneurial passion, opportunity recognition, and entrepreneurial behaviors. Entrepreneurial passion includes the intense positive feelings originating from engagement in entrepreneurial activities and the centrality of these activities for entrepreneurs’ self-identity. The empirical study was conducted using data from 195 entrepreneurs in new Chinese companies. Results showed that entrepreneurial passion had a significant impact on opportunity recognition and entrepreneurial behaviors. Further, opportunity recognition partly mediated the relationship between entrepreneurial passion and entrepreneurial behaviors. Entrepreneurs with entrepreneurial passion are, therefore, more likely than others are to identify opportunities and start new ventures. Theoretical and practical implications for entrepreneurship are discussed. [ABSTRACT FROM AUTHOR]

Although findings reported in an increasing number of studies shed light on the relationship between optimism and entrepreneurial outcomes, little is known of the mechanisms by which entrepreneurial optimism influences new venture performance. Researchers have found that people who are highly optimistic build more extensive social networks than others do, which can influence the outcome of their efforts. In order to explore the relationships among entrepreneurial optimism, social networks, and new venture performance, we analyzed data obtained from 142 Chinese entrepreneurs. Results indicated that entrepreneurial optimism had a significant impact on social network size, social network heterogeneity, and new venture performance. Social network size fully mediated the relationship between entrepreneurial optimism and new venture performance, but social network heterogeneity did not have a mediating role. These findings support the application of a social network perspective to gain a better understanding of the mechanism by which entrepreneurial optimism influences new venture performance. [ABSTRACT FROM AUTHOR]

10-kV silicon carbide (SiC) MOSFETs are currently being developed by a number of organizations in the U.S. with prospective applications in high-voltage and high-frequency power-electronic systems. The aim of this paper is to demonstrate the high-frequency and high-temperature capability of 10-kV SiC MOSFETs in the application of a dc/dc boost converter. In this study, 10-kV SiC MOSFET and junction barrier Schottky (JBS) diode were characterized and modeled in SPICE. Following this, a dc/dc boost converter based on a 10-kV 10-A MOSFET and a 10-kV 5-A JBS diode was designed and tested under continuous operation for frequencies up to 25 kHz. The boost converter had an output voltage of 4 kV, an output power of 4 kW, and operated with a junction temperature of 174 °C for the SiC MOSFET. The fast-switching speed, low losses, and high-temperature operation capability of 10-kV SiC MOSFETs demonstrated in the dc/dc boost converter make them attractive for high-frequency and high-voltage power-conversion applications. [ABSTRACT FROM AUTHOR]

Alternating current field measurement (ACFM) is a technology for detecting magnetic flux leakage (MFL) using a magnetic sensor and is often used to detect welding defects. An alternating magnetic field was generated under the excitation of an alternating electric field. The magnetic field direction of an alternating magnetic field changes with time and the size and direction of the leakage magnetic field on the weldment also change periodically. In order to verify this rule, the distribution of the leakage magnetic field in different magnetisation directions was analysed through simulation and experiment. The simulation results show that when sinusoidal excitation is applied to the coil, the direction of magnetisation changes with time and the magnetic field density (B) gradually changes periodically on the weldment. This was verified through related experiments. When the surface of the weldment had welding defects, the dynamic magneto-optical image was captured in different magnetisation directions. Welding defects have different magneto-optical images in different frames, which can present more information for the same defect. In addition, in the experiment, the correlation between the grey-level co-occurrence matrix (GLCM) of magneto-optical images in different magnetisation directions and that of the leakage magnetic field in the corresponding direction was analysed. Simulations and experiments were performed on different types of welding defect. It was found that the trend of characteristics for the leakage magnetic fields was similar to that of the characteristics for the grey-level co-occurrence matrix of the magneto-optical images. The results show that the characteristics of the leakage magnetic field can reflect the texture features of the welding defect. [ABSTRACT FROM AUTHOR]

Background: This study aims to report the treatment process and results of the first officially published robotic peripheral vascular interventional surgery for lower extremity arterial occlusion in China. After a literature search, no domestic or foreign research reports have been found that share the same research content and innovation points. Methods: A 77-year-old female patient with intermittent claudication received drug balloon dilatation using a universal vascular interventional surgery robotic system on June 17, 2023, at Peking Union Medical College Hospital (PUMCH). Results: With the help of the vascular interventional robot, the operation successfully re-opened the patient's nearly occluded blood vessel, and the patient's discomfort symptoms were relieved. The total operation lasted 60 min, which time was similar to surgeries without robots. The postoperative hospital stay was 2 days. Conclusion: This case has preliminarily verified the effectiveness and safety of vascular interventional robotic surgery. The initial study fills in the gaps in related fields and lays a solid foundation for the future development of universal vascular interventional robots. Larger scale trials and more clinical trials are needed to test and support the clinical application of universal vascular interventional robots. [ABSTRACT FROM AUTHOR]

Background: The mitochondrial GTPase mitofusin-2 (MFN2) gene encodes a mitochondrial membrane protein that can induce apoptosis of hepatocellular carcinoma (HCC) via the mitochondrial apoptotic pathway, as validated in our previous research. However, little is known of the clinical significance of MFN2 expression and its signaling pathways in HCC. Methods: MFN2 mRNA expression in tumor and adjacent non-tumor tissues from 115 patients with HCC was investigated using quantitative real-time PCR. The association of the MFN2 mRNA expression level with clinical and pathological parameters was evaluated statistically, while a comparative microarray analysis was used to identify MFN2 signaling pathways in HepG2 cells. Results: MFN2 was significantly (p < 0.0001) downregulated in HCC tissues. Low MFN2 expression was significantly correlated with sex and preoperative alpha-fetoprotein (p < 0.05). Both a Kaplan--Meier survival curve and multivariate analyses showed that MFN2 was related to overall survival. A comparative gene expression microarray revealed 211 upregulated (58 %) and 153 downregulated (42 %) genes. Eighteen pathways were identified as the most significant pathways correlated with MFN2. Conclusions: Low MFN2 expression in HCC indicated a worse overall survival. Crucial signaling molecules such as PI3K-AKT, cytokine receptor, and focal adhesion may participate in MFN2-mediated signaling pathway changes in HCC. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is rapidly becoming one of the most prevalent cancers worldwide and is a prominent source of mortality. Ras-related associated with diabetes (RRAD), one of the first members of the 35-39 kDa class of novel Ras-related GTPases, is linked to several types of cancer, although its function in HCC remains unclear. In this study, we observed that RRAD was downregulated in HCC compared with adjacent normal tissues. This change was associated with a poor prognosis. Furthermore, knockdown of RRAD in SK-Hep-1 cells facilitated cell proliferation, accelerated the G1/S transition during the cell cycle, induced cell migration, and reduced apoptosis. In contrast, overexpression of RRAD in Huh7 cells had the opposite effects. Moreover, we demonstrated that RRAD induced cell proliferation through regulation of the cell cycle by downregulating cyclins and cyclin-dependent kinases. RRAD induced tumor cell apoptosis through the mitochondrial apoptosis pathway. In addition, we confirmed that knockdown of RRAD promoted aerobic glycolysis by upregulating glucose transporter 1, whereas overexpression of RRAD inhibited aerobic glycolysis. In conclusion, RRAD plays a pivotal role as a potential tumor suppressor in HCC. An improved understanding of the roles of RRAD in tumor metabolism may provide insights into its potential as a novel molecular target in HCC therapy. [ABSTRACT FROM AUTHOR]

The clinical importance of intraductal papillary mucinous neoplasms (IPMN) of the pancreas has been increasing due to the large number of newly diagnosed cases. A meta-analysis was used to assess the accuracy of serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) for the identification of malignant and invasive IPMN. A literature search of PubMed and Web of Knowledge was conducted. Studies included in the analysis addressed the diagnostic accuracy of serum CEA and CA19-9 and pooled estimates of sensitivity, specificity, positive- and negative-likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR) and receiver operating characteristic curves were calculated using random-effects models. Predefined subgroup analysis was performed. Fifteen studies (published between 2001 and 2013) were analyzed, including a total of 1,629 patients. Pooled estimates of CEA in malignant and invasive IPNM prediction were: Pooled sensitivity, 18 and 18%; pooled specificity, 93 and 95%; PLR, 2.83 and 3.54; NLR, 0.89 and 0.89; and DOR, 3.35 and 3.6, respectively. Pooled estimates of CA19-9 in malignant and invasive IPMN prediction were: Pooled sensitivity, 40 and 52%; pooled specificity, 89 and 88%; PLR, 2.93 and 3.78; NLR, 0.74 and 0.6; and DOR, 4.34 and 6.33, respectively. In conclusion, serum CEA has low sensitivity and high specificity for malignant and invasive IPMN. Serum CA19-9 is a useful non-invasive preoperative tool for differentiating between invasive and benign IPMN and should be taken into account in the decision to perform surgery. [ABSTRACT FROM AUTHOR]