443 research outputs found

    Evacuation Hazards in Crowded Subway Stations

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    Underground subway system is the key transportation means in dense urban areas such as Hong Kong. Subway stations are crowded with passengers on the platforms and they are observed to squeeze into the train carriages during rush hours. Putting in platform screen doors made the situation even worse. As reported in the local news, subway management claims that after following the change in maximum capacity from six passengers per meter square to four passengers per meter square, the capacity is only 70% full at rush hours. However, the capacity can be over 90% of full loading under the new calculation. Subway stations become more crowded with an average weekday patronage of nearly 5.3 million passengers.  Subway stations are mostly located in the basement or ground levels connecting the shopping mall, commercial or residential building in downtown areas. The occupancy density of passengers can be much higher than expected during festivals with fireworks show and during large-scale movements such as Occupy Central. Therefore, evacuation time in emergency situation will be prolonged. To have a better understanding of the safety issue in subway stations, evacuation time in emergency situations will be studied in this paper.  Two subway stations, Station A and Station B are selected in this paper to study the evacuation hazard of crowded stations when a fire occurs. Station A is an interchange station between two railway lines, being one of the most crowded stations with high occupancy density. Station B is the first station in the local rail network to feature a special design - ñ€ƓLift-only Entrancesñ€. This is a deep underground station which lies under 70 m of ground level, the passengers have to be evacuated by lift. The occupancy density in Station B is relatively much lower than Station A under normal conditions at the moment, though the station can be very crowded if there are train delays due to signal failure or other reasons.  In this paper, the evacuation effectiveness of Station A and Station B are estimated in terms of evacuation time in different scenarios by using Hydraulic Model Calculation. Moreover, the special evacuation feature of ñ€ƓLift-only Entrancesñ€ in Station B and the fire safety management strategies for emergency evacuation will be discussed.  Three scenarios will be studied in each station:  Scenario A: Assume that the passengers are evenly distributed in different exits in emergency situation. All the possible factors such as passenger behaviors and conditions are eliminated.  Scenario B: Passengers have a higher tendency to evacuate at the larger exit, this is one of the passenger behaviors in emergency situation. Therefore, the passenger distribution which depends on the exit width will be studied.  Scenario C: Assume that some of the exit routes are blocked.  The most important factor for the above study is the passenger behaviors. As in scenario B, passenger behaviors would affect the evacuation time. Therefore, fire safety management is identified to be a key part in keeping efficient evacuation. For example, a good fire action plan on crowd control is needed

    Identification of compounds with anti-human cytomegalovirus activity that inhibit production of IE2 proteins

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    Using a high throughput screening methodology we surveyed a collection of largely uncharacterized validated or suspected kinase inhibitors for anti-human cytomegalovirus (HCMV) activity. From this screen we identified three structurally related 5-aminopyrazine compounds (XMD7-1, -2 and -27) that inhibited HCMV replication in virus yield reduction assays at low micromolar concentrations. Kinase selectivity assays indicated that each compound was a kinase inhibitor capable of inhibiting a range of cellular protein kinases. Western blotting and RNA sequencing demonstrated that treatment of infected cells with XMD7 compounds resulted in a defect in the production of the major HCMV transcriptional transactivator IE2 proteins (IE2-86, IE2-60 and IE2-40) and an overall reduction in transcription from the viral genome. However, production of certain viral proteins was not compromised by treatment with XMD7 compounds. Thus, these novel anti-HCMV compounds likely inhibited transcription from the viral genome and suppressed production of a subset of viral proteins by inhibiting IE2 protein production

    Anti-tumour effects of all-trans retinoid acid on serous ovarian cancer

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    BACKGROUND:Annexin A2 is increased in serous ovarian cancer and plays an essential role in ovarian cancer invasion and metastasis. In combination with S100A10, annexin A2 plays an important role in the plasminogen activator system regulating plasmin production. The aim of this study was to investigate the potential utility of all-trans retinoid acid (ATRA), an inhibitor of the annexin A2-S100A10 signalling pathway, as a new therapeutic against serous ovarian cancer. METHODS:In this study we determined the effects of ATRA treatment (1-5 ΌM) on annexin A2 and S100A10 expression, plasmin activation, and the ability of ATRA to inhibit serous ovarian cancer cell survival, motility and invasion in vitro. We also employed an ex vivo tissue explant assay to assess response to ATRA treatment in serous ovarian cancers. Cryopreserved serous ovarian cancer tissues were cultured on gelatin sponges for 72 h with ATRA (1 ΌM). Effects on apoptosis and proliferation were assessed by immunohistochemistry using antibodies to cleaved caspase 3 or Ki67, respectively. RESULTS:Survival of serous ovarian cancer cells (OVCAR-3, OV-90, & OAW28) was significantly decreased by ATRA treatment (1-5 ΌM). ATRA (1 ΌM) also significantly decreased proliferation (Ki67 positivity, p = 0.0034), S100A10 protein levels (p = 0.0273), and increased cell apoptosis (cleaved caspase-3 positivity, p = 0.0024) in serous ovarian cancer tissues using the ex vivo tissue explant assay. In OAW28 cells, reduced cell survival following ATRA treatment was associated with a reduction of S100A10 mRNA and protein levels, S100A10 and annexin A2 membrane localization, plasmin generation, motility and invasion. In contrast, ATRA inhibited OV-90 cell survival and invasion but did not affect plasmin activation or S100A10 and annexin A2 expression or membrane localization. CONCLUSIONS:These findings suggest that ATRA inhibits serous ovarian cancer proliferation and invasion via both S100A10 dependant and S100A10 independent mechanisms. Our results show that ATRA has promising potential as a novel therapy against serous ovarian cancer that warrants further evaluation.Noor A. Lokman, Rachel Ho Kavyadharshini Gunasegaran, Wendy M. Bonner, Martin K. Oehler and Carmela Ricciardell

    Remarks on 't Hooft's Brick Wall Model

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    A semi-classical reasoning leads to the non-commutativity of the space and time coordinates near the horizon of Schwarzschild black hole. This non-commutativity in turn provides a mechanism to interpret the brick wall thickness hypothesis in 't Hooft's brick wall model as well as the boundary condition imposed for the field considered. For concreteness, we consider a noncommutative scalar field model near the horizon and derive the effective metric via the equation of motion of noncommutative scalar field. This metric displays a new horizon in addition to the original one associated with the Schwarzschild black hole. The infinite red-shifting of the scalar field on the new horizon determines the range of the noncommutativ space and explains the relevant boundary condition for the field. This range enables us to calculate the entropy of black hole as proportional to the area of its original horizon along the same line as in 't Hooft's model, and the thickness of the brick wall is found to be proportional to the thermal average of the noncommutative space-time range. The Hawking temperature has been derived in this formalism. The study here represents an attempt to reveal some physics beyond the brick wall model.Comment: RevTeX, 5 pages, no figure

    Center on Disability Studies eNewsletter, December 2023

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    As the year draws to a close and the holiday season is upon us, I want to extend my gratitude to our partners, collaborators, participants, students, and stakeholders on behalf of CDS. We genuinely appreciate the collective efforts that continually contribute to the success of our projects and initiatives. Looking ahead, we're gearing up for our Pac Rim Conference in February 2024, centered around the theme "Beyond Access: Building a Culture of Belonging," a concept we're deeply passionate about. This ethos guides our efforts within our unit and throughout our projects. Additionally, I encourage you to read about Dr. Steve Brown and his impactful legacy on CDS, within the AUCD network, and on Disability Culture. We celebrate his life and honor his memory

    Center on Disability Studies eNewsletter, June 2023

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    Welcome to our summer newsletter. In this issue we highlight many events and happenings sponsored by CDS during June and July that you don’t want to miss out on. Disability Pride Month is also celebrated each year in July. Disability Pride initially started as a day of celebration in 1990, the year that the Americans with Disabilities Act (ADA) was signed into law. It is also an opportunity to raise awareness about improving access and inclusion. The first official Disability Pride celebration occurred in 2015 to commemorate the ADA’s 25th anniversary and the Disability Pride Flag was originally designed in 2019 by Ann Magill, who with feedback within the disabled community, refined its visual elements in 2021 to be more accessible. You can read more about how the disability pride flag helps increase the community’s visibility at https://go.hawaii.edu/qEX

    Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

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    Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Fabrication, Modeling and Characterization of Multi-Crosslinked Methacrylate Copolymeric Nanoparticles for Oral Drug Delivery

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    Nanotechnology remains the field to explore in the quest to enhance therapeutic efficacies of existing drugs. Fabrication of a methacrylate copolymer-lipid nanoparticulate (MCN) system was explored in this study for oral drug delivery of levodopa. The nanoparticles were fabricated employing multicrosslinking technology and characterized for particle size, zeta potential, morphology, structural modification, drug entrapment efficiency and in vitro drug release. Chemometric Computational (CC) modeling was conducted to deduce the mechanism of nanoparticle synthesis as well as to corroborate the experimental findings. The CC modeling deduced that the nanoparticles synthesis may have followed the mixed triangular formations or the mixed patterns. They were found to be hollow nanocapsules with a size ranging from 152 nm (methacrylate copolymer) to 321 nm (methacrylate copolymer blend) and a zeta potential range of 15.8–43.3 mV. The nanoparticles were directly compressible and it was found that the desired rate of drug release could be achieved by formulating the nanoparticles as a nanosuspension, and then directly compressing them into tablet matrices or incorporating the nanoparticles directly into polymer tablet matrices. However, sustained release of MCNs was achieved only when it was incorporated into a polymer matrix. The experimental results were well corroborated by the CC modeling. The developed technology may be potentially useful for the fabrication of multi-crosslinked polymer blend nanoparticles for oral drug delivery
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