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    Quyen Nguyen

    Many institutions rely on open systems to provide services to the public via the Internet. Unanticipated software vulnerabilities expose such services to malicious actors, and make them susceptible to attacks. Therefore, security is... more
    Many institutions rely on open systems to provide services to the public via the Internet. Unanticipated software vulnerabilities expose such services to malicious actors, and make them susceptible to attacks. Therefore, security is critical in order to ensure confidentiality, integrity, and availability for system data and services. The fact that security attacks have become increasingly sophisticated makes the protection of
    Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern... more
    Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern patient survival. We find that TP53 mutation is frequently accompanied by loss of chromosome 3p and that the combination of these events is associated with a surprising decrease in survival time (1.9 years versus >5 years for TP53 mutation alone). The TP53-3p interaction is specific to chromosome 3p and validates in HNSCC and pan-cancer cohorts. In human papillomavirus (HPV)-positive tumors, in which HPV inactivates TP53, 3p deletion is also common and is associated with poor outcomes. The TP53-3p event is modified by mir-548k expression, which decreases survival further, and is mutually exclusive with mutations affecting RAS signaling. Together, the identified markers underscore the molecular heterogeneity of HNSCC and enable a new multi-tiered classification of this disease.
    A large body of evidence shows that molecular cues promote specific synapse formation by guiding axons and by mediating their association with targets, but much less is known about the contribution of physical cues (such as mechanical... more
    A large body of evidence shows that molecular cues promote specific synapse formation by guiding axons and by mediating their association with targets, but much less is known about the contribution of physical cues (such as mechanical constraints) to these processes. Here we used the peripheral motor system to investigate the latter issue. In living mice, we viewed individual motor axons bearing a fluorescent reporter, and mapped the cohort of muscle fibers that they innervated both before and after nerve damage. When gross trauma was minimized (by a nerve-crushing rather than nerve-cutting procedure), regenerating axons retraced their former pathways, bifurcated at original branch points, and formed neuromuscular junctions on the same fibers that they originally innervated. Axonal growth through tubes of non-neural cells seemed to account for this specificity, and specificity degraded when the tubes were cut. These results suggest that nonspecific guidance cues can be sufficient to...
    Nerve degeneration after transection injury decreases intraoperative visibility under white light (WL), complicating surgical repair. We show here that the use of fluorescently labeled nerve binding probe (F-NP41) can improve... more
    Nerve degeneration after transection injury decreases intraoperative visibility under white light (WL), complicating surgical repair. We show here that the use of fluorescently labeled nerve binding probe (F-NP41) can improve intraoperative visualization of chronically (up to 9 months) denervated nerves. In a mouse model for the repair of chronically denervated facial nerves, the intraoperative use of fluorescent labeling decreased time to nerve identification by 40% compared to surgeries performed under WL alone. Cumulative functional post-operative recovery was also significantly improved in the fluorescence guided group as determined by quantitatively tracking of the recovery of whisker movement at time intervals for 6 weeks post-repair. To our knowledge, this is the first description of an injectable probe that increases visibility of chronically denervated nerves during surgical repair in live animals. Future translation of this probe may improve functional outcome for patients...
    Intrinsic tumor resistance to radiotherapy limits the efficacy of ionizing radiation (IR). Sensitizing cancer cells specifically to IR would improve tumor control and decrease normal tissue toxicity. The development of tumor targeting... more
    Intrinsic tumor resistance to radiotherapy limits the efficacy of ionizing radiation (IR). Sensitizing cancer cells specifically to IR would improve tumor control and decrease normal tissue toxicity. The development of tumor targeting technologies allows for developing potent radiosensitizing drugs. We hypothesized that the anti-tubulin agent monomethyl auristatin E (MMAE), a component of a clinically approved antibody-directed conjugate, could function as a potent radiosensitizer and be selectively delivered to tumors using an activatable cell penetrating peptide targeting matrix metalloproteinases and RGD binding integrins (ACPP-cRGD-MMAE). We evaluated the ability of MMAE to radiosensitize both established cancer cells and a low passage cultured human pancreatic tumor cell line using clonogenic and DNA damage assays. MMAE sensitized colorectal and pancreatic cancer cells to IR in a schedule and dose dependent manner correlating with mitotic arrest. Radiosensitization was evidence...
    We present an optimized triple modality reporter construct combining a far-red fluorescent protein (E2-Crimson), enhanced firefly luciferase enzyme (Luc2), and truncated wild type herpes simplex virus I thymidine kinase (wttk) that allows... more
    We present an optimized triple modality reporter construct combining a far-red fluorescent protein (E2-Crimson), enhanced firefly luciferase enzyme (Luc2), and truncated wild type herpes simplex virus I thymidine kinase (wttk) that allows for sensitive, long-term tracking of tumor growth in vivo by fluorescence, bioluminescence, and positron emission tomography. Two human cancer cell lines (MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer) were successfully transduced to express this triple modality reporter. Fluorescence and bioluminescence imaging of the triple modality reporter were used to accurately quantify the therapeutic responses of MDA-MB-231 tumors to the chemotherapeutic agent monomethyl auristatin E in vivo in athymic nude mice. Positive correlation was observed between the fluorescence and bioluminescence signals, and these signals were also positively correlated with the ex vivo tumor weights. This is the first reported use of both fluorescence and bioluminescence signals from a multi-modality reporter construct to measure drug efficacy in vivo.
    Abstract Approaches to supporting real-time communication allocate network resources either to individual connections, or to aggregates of connections. Resource sharing is a new approach that exploits known relationships between related... more
    Abstract Approaches to supporting real-time communication allocate network resources either to individual connections, or to aggregates of connections. Resource sharing is a new approach that exploits known relationships between related connections to allow network ...
    Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern... more
    Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern patient survival. We find that TP53 mutation is frequently accompanied by loss of chromosome 3p and that the combination of these events is associated with a surprising decrease in survival time (1.9 years versus >5 years for TP53 mutation alone). The TP53-3p interaction is specific to chromosome 3p and validates in HNSCC and pan-cancer cohorts. In human papillomavirus (HPV)-positive tumors, in which HPV inactivates TP53, 3p deletion is also common and is associated with poor outcomes. The TP53-3p event is modified by mir-548k expression, which decreases survival further, and is mutually exclusive with mutations affecting RAS signaling. Together, the identified markers underscore the molecular heterogeneity of HNSCC and enable a new multi-tiered classification of this disease.
    Current approaches to supporting real-time communication allocate network re-sources either to individual connections, or to aggregates of connections, based on type of tra c, protocol, or performance requirements. The rst approach... more
    Current approaches to supporting real-time communication allocate network re-sources either to individual connections, or to aggregates of connections, based on type of tra c, protocol, or performance requirements. The rst approach provides well-de ned ...
    Abstract. There is considerable interest in the network community in supporting real-time multi-party applications, such as video conferenc-ing. The Tenet Group at UC Berkeley and ICSI has designed and im-plemented protocols that provide... more
    Abstract. There is considerable interest in the network community in supporting real-time multi-party applications, such as video conferenc-ing. The Tenet Group at UC Berkeley and ICSI has designed and im-plemented protocols that provide quality o] service (QoS) ...
    1. To correlate exostosis severity with ear canal evaporative cooling. 2. To assess hearing and complications after canalplasty. Retrospective chart review. A retrospective chart review from 1990 to 2007 at a university tertiary referral... more
    1. To correlate exostosis severity with ear canal evaporative cooling. 2. To assess hearing and complications after canalplasty. Retrospective chart review. A retrospective chart review from 1990 to 2007 at a university tertiary referral center. Surfers from the west coast of the United States were twice as likely to have severe exostoses in the right ear compared with the left. Evaporative cooling from a predominant northerly wind direction during the coldest water temperature months in this region may contribute to this lateral bias because surfers on this coast spend most of their time facing west. Few postoperative complications were identified. No cases of facial nerve injury or entry into the temporomandibular joint occurred. Differences in preoperative versus postoperative pure-tone hearing thresholds were not significant. Exostosis severity seems to correspond to the ear that is more exposed to the predominant coastal wind. We propose that evaporative cooling in a cold water environment contributes to greater progression of exostoses in the ear with more exposure to the predominant wind. Exostosis removal using the postauricular approach carries a low complication rate.