238 research outputs found

    Terahertz Sources, Detectors, and Transceivers in Silicon Technologies

    Get PDF
    With active devices lingering on the brink of activity and every passive device and interconnection on chip acting as potential radiator, a paradigm shift from “top-down” to “bottom-up” approach in silicon terahertz (THz) circuit design is clearly evident as we witness orders-of-magnitude improvements of silicon THz circuits in terms of output power, phase noise, and sensitivity since their inception around 2010. That is, the once clear boundary between devices, circuits, and function blocks is getting blurrier as we push the devices toward their limits. And when all else fails to meet the system requirements, which is often the case, a logical step forward is to scale these THz circuits to arrays. This makes a lot of sense in the terahertz region considering the relatively efficient on-chip THz antennas and the reduced size of arrays with half-wavelength pitch. This chapter begins with the derivation of conditions for maximizing power gain of active devices. Discussions of circuit topologies for THz sources, detectors, and transceivers with emphasis on their efficacy and scalability ensue, and this chapter concludes with a brief survey of interface options for channeling THz energy out of the chip

    MiR-21 induced angiogenesis through AKT and ERK activation and HIF-1α expression.

    Get PDF
    MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated kinases (ERK) 1/2 are activated by miR-21. Inhibition of miR-21 by the antigomir blocked this process. Overexpression of the miR-21 target, PTEN, also inhibited tumor angiogenesis by partially inactivating AKT and ERK and decreasing the expression of HIF-1 and VEGF. The AKT and ERK inhibitors, LY294002 and U0126, suppressed HIF-1α and VEGF expression and angiogenesis. Moreover, inhibition of HIF-1α expression alone abolished miR-21-inducing tumor angiogenesis, indicating that HIF-1α is required for miR-21-upregulated angiogenesis. Therefore, we demonstrate that miR-21 induces tumor angiogenesis through targeting PTEN, leading to activate AKT and ERK1/2 signaling pathways, and thereby enhancing HIF-1α and VEGF expression; HIF-1α is a key downstream target of miR-21 in regulating tumor angiogenesis

    A Fast and Robust Ellipse-Detection Method Based on Sorted Merging

    Get PDF
    A fast and robust ellipse-detection method based on sorted merging is proposed in this paper. This method first represents the edge bitmap approximately with a set of line segments and then gradually merges the line segments into elliptical arcs and ellipses. To achieve high accuracy, a sorted merging strategy is proposed: the merging degrees of line segments/elliptical arcs are estimated, and line segments/elliptical arcs are merged in descending order of the merging degrees, which significantly improves the merging accuracy. During the merging process, multiple properties of ellipses are utilized to filter line segment/elliptical arc pairs, making the method very efficient. In addition, an ellipse-fitting method is proposed that restricts the maximum ratio of the semimajor axis and the semiminor axis, further improving the merging accuracy. Experimental results indicate that the proposed method is robust to outliers, noise, and partial occlusion and is fast enough for real-time applications

    ELISA for Aging Biomarkers Induced by Telomere Dysfunction in Human Plasma

    Get PDF
    Background. We identified cathelicidin related antimicrobial protein (CRAMP) secreted from telomere dysfunctional bone marrow cells of late generation telomerase knockout mice (G4mTerc−/−), increased in blood and various tissues. It can represented human aging and disease. The main aim of this study is to investigate the sensitive direct enzyme-linked immunosorbent assay (ELISA) method to analyze the human aging and disease in plasma and the detailed methods to quantify the direct ELISA of these aging biomarkers. Methods. Telomere lengths of 50 healthy persons are measured with real-time PCR in blood cells. Plasma samples from all subjects are analyzed using direct ELISA. Results. From 25 years old person to 78 years, the telomere length becomes shorter during aging. In blood plasma, the expression levels of CRAMP increases during human aging. There is the reverse correspondence between the telomere length and the plasma CRAMP level. We also find that the fresh plasma, the frozen plasma which thawed less than 3 times, and the plasma kept in the room temperature less than 3 hours are better for the ELISA analyze of CRAMP in the plasma. Conclusion. This CRAMP ELISA could become a powerful tool for investigating the relationship between human aging and telomere length shortening

    Promoting cellulase and hemicellulase production from Trichoderma orientalis EU7-22 by overexpression of transcription factors Xyr1 and Ace3.

    Get PDF
    The construction of hyper-production strains of cellulase is the prerequisite for the production of biofuels or biochemicals. Trichoderma orientalis EU7-22 with complete cellulase system shows the potential for cellulase production in industrial scale. To improve the cellulase production, two crucial transcription activators Xyr1 and Ace3 were constitutively overexpressed in EU7-22 strain. Cellulase, xylanase and protein secretion were significantly improved in the recombinant strain dxyA-8 under inducing culture, which were 2.34, 0.68 and 1.06 folds higher than those of EU7-22, respectively. Moreover, the FPase and CMCase activities were up to 2.55 IU/mL and 90.38 IU/mL with glucose as carbon source, which were 2.12 and 1.95 folds higher than those of EU7-22 under inducing condition, respectively. Reducing sugar released from pretreated spartina that hydrolyzed by crude enzyme from dxyA-8 had achieved 24% improvement. Therefore, overexpression of these transcription factors effectively promotes the production of cellulase and hemicellulase of Trichoderma orientalis EU7-22

    Promoting cellulase and hemicellulase production from Trichoderma orientalis EU7-22 by overexpression of transcription factors Xyr1 and Ace3

    Get PDF
    Abstract(#br)The construction of hyper-production strains of cellulase is the prerequisite for the production of biofuels or biochemicals. Trichoderma orientalis EU7-22 with complete cellulase system shows the potential for cellulase production in industrial scale. To improve the cellulase production, two crucial transcription activators Xyr1 and Ace3 were constitutively overexpressed in EU7-22 strain. Cellulase, xylanase and protein secretion were significantly improved in the recombinant strain dxyA-8 under inducing culture, which were 2.34, 0.68 and 1.06 folds higher than those of EU7-22, respectively. Moreover, the FPase and CMCase activities were up to 2.55 IU/mL and 90.38 IU/mL with glucose as carbon source, which were 2.12 and 1.95 folds higher than those of EU7-22 under inducing condition, respectively. Reducing sugar released from pretreated spartina that hydrolyzed by crude enzyme from dxyA-8 had achieved 24% improvement. Therefore, overexpression of these transcription factors effectively promotes the production of cellulase and hemicellulase of Trichoderma orientalis EU7-22

    Behavioral and eye movement study of attention bias to alcohol-related cues in male alcohol-dependent patients and correlation analysis of psychological factors

    Get PDF
    Objective·To investigate if male alcohol-dependent patients have attention bias to alcohol-related pictures, show the behavioral and eye movement characteristics of attention bias, and explore the correlation between attention bias and sleep, anxiety, depression, impulsion and other psychological factors.Methods·Twenty-nine subjects in the case group (alcohol-dependent patients who were hospitalized in Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, from August 2021 to February 2022) and 29 healthy subjects in the healthy control group participated in the study. The experimental design was a mixed experimental design of three-factor hybrid. The cue types were alcohol-related and emotion pictures. The probe was on the same side or on the opposite side of the alcohol or emotional picture. The characteristics of subjects' attentional bias to alcohol cues were investigated by using the classical dot detection paradigm and eye movement monitoring technique. Groups were inter-group variables, and clue types and relative locations of probe points were intra-group variables. The behavioral and eye movement data were collected while the study subjects viewed pairs of alcohol-related and neutral pictures, or pairs of emotional and neutral pictures in a dot-probe paradigm. Dependent variables included behavioral indicators and eye movement indicators. Pittsburgh Sleep Quality Index (PSQI), 7-tiem Generalized Anxiety Disorder Scale (GAD-7), Patien Health Questionnaire (PHQ-9), and Barratt Impulsiveness Scale (BIS-11) scales were used to assess psychosomatic conditions such as sleep, anxiety, depression, and impulsivity, respectively. Behavioral and eye movement characteristics of attention bias in the alcohol-dependent group were analyzed. In addition, the correlation with behavioral and eye movement characteristics of attention bias and scale scores was analyzed.Results·The behavioral results showed that the reaction time of the alcohol-dependent group was significantly longer than that of the healthy control group (P=0.006). The eye movement results showed that when the type of cue was alcohol-related picture, the alcohol-dependent group had slower attention detection (P=0.031) and longer attention maintenance (P=0.005) on alcohol-related cues. Moreover, the pupil size during the viewing of alcohol-related cues (P=0.001) and emotional cues (P=0.008) were significantly smaller than those of the healthy control group. It was also found that, there was a negative correlation between the correct rate of the alcohol-dependent group and the BIS-11 scale score (r=-0.437, P=0.032), and a positive correlation between reaction time and GAD-7 score (r=0.407, P=0.033). The time of the first visual fixation entry was positively correlated with GAD-7 score (r=0.414, P=0.045), and the PSQI score was positively correlated with PHQ-9 score (r=0.422, P=0.041) in the case group.Conclusion·Alcohol-dependent patients have attention bias towards alcohol-related cues according to the behavioral and eye movement result. Compared with the traditional behavioral regression of attention bias based on correct rate and reaction time results, eye movement provides more direct and multi indicator evidence for the evaluation of attention bias in alcohol-dependent patients
    • 

    corecore