Inhibition of thiol isomerase activity diminishes endothelial activation of plasminogen, but not of protein C

Highlights •A range of thiol isomerase enzymes were expressed by HMEC-1 endothelial cells. •Inhibition of thiol isomerases reduced plasminogen activation on HMEC-1 cells. •Exogenous bovine protein disulphide isomerase increased plasminogen activation in HMEC-1 cells. •Inhibition of thiol isomerases also reduced fibrin clot lysis, but not via direct effects on tPA. •HMEC-1 mediated protein C activation was unaffected by thiol isomerase inhibition. Abstract Introduction Cell surface thiol isomerase enzymes, principally protein disulphide isomerase (PDI), have emerged as important regulators of platelet function and tissue factor activation via their action on allosteric disulphide bonds. Allosteric disulphides are present in other haemostasis-related proteins, and we have therefore investigated whether thiol isomerase inhibition has any influence on two endothelial activities relevant to haemostatic regulation, namely activation of protein C and activation of plasminogen, with subsequent fibrinolysis. Materials and Methods The study was performed using the human microvascular endothelial cell line HMEC-1. Thiol isomerase gene expression was measured by RT-PCR and activation of protein C and plasminogen by cell-based assays using chromogenic substrates S2366 and S2251, respectively. Cell mediated fibrinolysis was measured by monitoring absorbance at 405 nm following fibrin clot formation on the surface of HMEC-1 monolayers. Results and Conclusions A variety of thiol isomerase enzymes, including PDI, were expressed by HMEC-1 cells and thiol reductase activity detectable on the cell surface was inhibited by both RL90 anti-PDI antibody and by the PDI inhibitor quercetin-3-rutinoside (rutin). In cell-based assays, activation of plasminogen, but not of protein C, was inhibited by RL90 antibody and, to a lesser extent, by rutin. Fibrin clot lysis occurring on a HMEC-1 monolayer was also significantly slowed by RL90 antibody and by rutin, but RL90-mediated inhibition was abolished in the presence of exogenous tissue plasminogen activator (tPA). We conclude that thiol isomerases, including PDI, are involved in fibrinolytic regulation at the endothelial surface, although not via a direct action on tPA. These findings broaden understanding of haemostatic regulation by PDI, and may aid in development of novel anti-thrombotic therapeutic strategies targeted via the fibrinolysis system

Kiprah dan pemikiran Usmar Ismail dalam perfilman nasional Indonesia tahun 1949-1971

Penelitian ini membahas mengenai kiprah dan pemikiran Usmar Ismail dalam sejarah film Indonesia. Usmar Ismail adalah tokoh yang dikenal sebagai Bapak Perfilman Nasional Indonesia yang memiliki banyak kontribusi selama kiprahnya dalam berkarir di dunia perfilman Indonesia dengan segala kemampuan yang dimilikinya. Sebagai seorang tokoh yang memiliki sikap nasionalis dan religius Usmar Ismail juga memiliki pemikiran tentang bagaimana film Indonesia seharusnya diciptakan dan mempunyai pemikiran bahwa film bisa dijadikan sebagai media dakwah. Tujuan penelitian ini adalah pertama untuk mengetahui kondisi perfilman Indonesia pada tahun 1949-1971, kedua untuk mengetahui kiprah Usmar Ismail dalam sejarah film Indonesia tahun 1949-1971, dan ketiga untuk mengetahui pemikiran Usmar Ismail tentang film Indonesia. Adapun metode yang digunakan dalam penelitian ini adalah metode penelitian sejarah, yaitu penelitian yang mempelajari peristiwa atau kejadian-kejadian masa lalu berdasarkan jejak-jejak yang dihasilkannya, melalui empat tahap yaitu: pertama heuristik (pengumpulan sumber), kedua kritik (kritik intern dan kritik ekstern), ketiga interpretasi dan keempat historiografi (penulisan sejarah). Berdasarkan hasil penelitian yang dilakukan, maka didapatkan kesimpulan yaitu kondisi perfilman Indonesia tahun 1949-1971 terbagi pada tiga periode yaitu masa pemulihan kondisi perfilman Indonesia tahun 1949-1960, masa masuknya pengaruh PKI dalam dunia perfilman Indonesia tahun 1960-1965, dan masa-masa sulit bagi film nasional Indonesia tahun 1965-1971. Kiprah Usmar Ismail dalam sejarah film Indonesia diawali tahun 1949 bersamaan dengan dimulainya masa pemulihan kondisi perfilman. Dalam kiprahnya Usmar Ismail berhasil mendirikan perusahaan film yaitu PERFINI tahun 1950, kemudian berhasil mencetak kader-kader baru dalam dunia perfilman, serta mempelopori pola baru dalam penciptaan film. Dalam kiprahnya Usmar Ismail juga mendapat hambatan saat berpengaruhnya orang-orang PKI dalam dunia perfilman Indonesia. Usmar Ismail mengakhiri karirnya dalam dunia perfilman bersamaan dengan masa sulit bagi perfilman nasional dan Usmar Ismail akhirnya meninggal pada tanggal 2 Januari 1971. Kemudian pemikiran Usmar Ismail tentang film Indonesia mencerminkan sikap nasionalisme dan religiusnya dalam kiprahnya di dunia perfilman Indonesia. Pemikiran Usmar Ismail ini terlihat dalam setiap karya yang telah dihasilkannya

An Early Drowning Detection System for Internet of Things (IoT) Applications

Drowning is the leading cause of injury or death for children and teenagers. Designing a drowning detection device by implementing an Internet of Thing (IoT) is needed. An Early Drowning Detection System (EDDS) is a system that gives an early alarm to the guardians (parents and lifeguard) if the detector triggered an abnormal heartbeat and the victims are submerged under the water for a long time. A microcontroller was used to control the signal received from a pulse sensor and time for the signal lost under the water before it is transmitted to the access point. The access point acts as a data forwarding to the database via an internet connection. Universal Asynchronous Receiver/Transmitter (UART) 433MHz radio frequency transceiver has been used to create the wireless communication between drowning detection device and monitoring hub. A triggered warning signal will be transmitted to the guardians via Android apps and web page

Energy detection based cooperative spectrum sensing system for emergency networks

During emergencies, a number of rescue teams come to the field and setup their own radio communication systems. If the deployed communication setup does not coordinate among themselves properly, they may interfere with each other when using the same RF channels known as co-channel interference. Spectrum sensing is the most important and complex job for cognitive radios. Cooperation among cognitive radio nodes is needed to enhance the sensing performance. In this paper, we present an experimental study of this solution. A Software Defined Radio comprising of GNU Radio and USRP were used to capture the signal samples to build a database profile of the spectrum condition. MATLAB communications toolbox was used to analyze the data and examine the spectrum pertaining to the condition in emergency networks. The benefits of cooperative spectrum sensing in avoiding co-channel interference during emergency situations are illustrated. Cooperation among cognitive spectrum sensing nodes operating at the same frequency improves the probability of detection, and the overall efficiency of the system. Results show that the cooperative sensing scheme outperforms the individual sensing approach. It can increases the probability of detection relative to the collected samples as the key performance indicator

Assessment of seismic scenario-structure based limit state criteria for a reinforced concrete high-rise building

Issues regarding reinforced concrete (RC) high-rise buildings involve different seismic scenarios, such as near- and far-field earthquakes, which can result in different levels and complex seismic scenario structures related to global damage. This study aims to evaluate the seismic scenario structures of a 23-storey RC high-rise building based on different damage measures and to develop a fragility curve with different limit state criteria. Six ground motions are selected to represent two seismic scenarios. Seismic scenario-based global response of the building at increasing earthquake intensity measures is adopted using incremental dynamic analysis (IDA). IDA curves and interstorey drift are used in the parametric study. The structural performance and damage measure of RC high-rise buildings are evaluated with performance-based seismic design limit state. The four performance levels proposed by ATC-43 are operational performance, immediate occupancy, life safety and collapse prevention. The IDA curves showed that near-field effect has a high frequency that gives impact at early intensity measures on building collapse compared with far-field effect. Meanwhile, interstorey drift result indicates that the near-field effect has a larger effect on building damages compared with the far-field effect. Based on the fragility curves, near-field earthquakes have a larger effect towards structural damages than far-field earthquakes

Spectrum occupancy measurement: a case for cognitive radio network in lagos, Nigeria

The proliferation in technologies and with the recent introduction of new paradigm for wireless communication, the demand for wireless devices has increased drastically in recent years. This therefore, posed a major threat on the available frequency spectrum and as a result, an efficient method for the utilisation of the limited frequency spectrum is required. As the scarcity of frequency spectrum is a major problem in the telecommunication field, cognitive radio technology has been identified as a promising solution to this problem. Cognitive radio allows the opportunistic access of licensed bands by unlicensed users without causing harmful interference to the licensed user. There is a need to evaluate the utilisation level of the licensed bands in order to identify which frequency bands can be used for cognitive radio implementation. Nevertheless, spectrum measurement campaigns have been conducted mostly in USA and a few other locations around the world. In this paper, the results of the measurement campaign conducted in Ikeja, the capital city of Lagos, Nigeria covering the range of frequency 700 MHz up to 2.2 GHz is presented. The measurement results are analysed and compared to the frequency allocation table published by the Nigerian Communications Commission. The results obtained show that the frequency spectrum is underutilised and therefore a significant amount of spectrum is available for the future implementation of cognitive radio networks

Interference temperature measurements and spectrum occupancy evaluation in the context of cognitive radio

This paper presents a refined radio spectrum measurement platform specifically designed for spectrum occupancy surveys in the context of Cognitive radio. Cognitive radio permits the opportunistic usage of licensed bands by unlicensed users without causing harmful interference to the licensed user. In this work, a study based on the measurement of the 800 MHz to 2.4 GHz frequency band at two different locations inside Universiti Teknologi Malaysia (UTM), Johor Bahru campus, Malaysia is presented. Two Tektronix RSA306B spectrum analyzer are set up to conduct simultaneous measurements at different locations for a 24 hours period. The analysis conducted in this work is based on the real spectrum data acquired from environment in the experimental set up. Busy and idle channels were identified. The channels subject to adjacent-channel interference were also identified, and the impact of the detection threshold used to detect channel activities was also discussed. The consistency of the observed channel occupation over a range of thresholds and a sudden drop has good characteristics in determining an appropriate threshold needed in order to avoid interference