1,482 research outputs found

    PALS/PRISM Software Design Description (SDD): Ver. 0.51

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    This Software Design Description (SDD) provides detailed information on the architecture and coding for the PRISM C++ library (version 0.51). The PRISM C++ library supports consistent information sharing and in- teractions between distributed components of networked embedded systems, e.g. avionics. It is designed to reduce the complexity of the networked sys- tem by employing synchronous semantics provided by the architectural pat- tern called a Physically-Asynchronous Logically-Synchronous (PALS) system.unpublishednot peer reviewe

    Low complexity system architecture design for medical Cyber-Physical-Human Systems (CPHS)

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    Cyber-Physical-Human Systems (CHPS) are safety-critical systems, where the interaction between cyber components and physical components can be influenced by the human operator. Guaranteeing correctness and safety in these highly interactive computations is challenging. In particular, the interaction between these three components needs to be coordinated collectively in order to conduct safe and effective operations. The interaction nevertheless increases by orders of magnitude the levels of complexity and prevents formal verification techniques, such as model checking, from thoroughly verifying the safety and correctness properties of systems. In addition, the interactions could also significantly increase human operators' cognitive load and lead to human errors. In this thesis, we focus on medical CPHS and examine the complexity from a safety angle. Medical CPHS are both safety-critical and highly complex, because medical staff need to coordinate with distributed medical devices and supervisory controllers to monitor and control multiple aspects of the patient's physiology. Our goal is to reduce and control the complexity by introducing novel architectural patterns, coordination protocols and user-centric guidance system. This thesis makes three major contributions for improving safety of medical CPHS. Reducing verification complexity: Formal verification is a promising technique to guarantee correctness and safety, but the high complexity significantly increases the verification cost, which is known as state space explosion problems. We propose two architectural patterns: Interruptible Remote Procedure Call (RPC) and Consistent View Generation and Coordination (CVGC) protocol to properly handle asynchronous communication and exceptions with low complexity. Reducing cyber-medical treatment complexity: Cyber medical treatment complexity is defined as the number of steps and time to perform a treatment and monitor the corresponding physiological responses. We propose treatment and workflow adaptation and validation protocols to semi-autonomously validate the preconditions and adapt the workflows to patient conditions, which reduces the complexity of performing treatments and following best practice workflows. Reducing human cognitive load complexity: Cognitive load (also called mental workload) complexity measures human memory and mental computation demand for performing tasks. We first model individual medical staff's responsibility and team interactions in cardiac arrest resuscitation and decomposed their overall task into a set of distinct cognitive tasks that must be specifically supported to achieve successful human-centered system design. We then prototype a medical Best Practice Guidance (BPG) system to reduce medical staff's cognitive load and foster adherence to best practice workflows. Our BPG system transforms the implementation of best practice medical workflow

    In Situ Confocal Raman Mapping Study of a Single Ti-Assisted ZnO Nanowire

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    In this work, we succeeded in preparing in-plane zinc oxide nanowires using a Ti-grid assisted by the chemical vapor deposition method. Optical spatial mapping of the Confocal Raman spectra was used to investigate the phonon and geometric properties of a single ZnO nanowire. The local optical results reveal a red shift in the non-polar E2 high frequency mode and width broadening along the growth direction, reflecting quantum-confinement in the radial direction

    Langerhans cell hyperplasia in the tumor stage of mycosis fungoides: a mimic of Langerhans cell histiocytosis

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    AbstractMycosis fungoides is a form of cutaneous T-cell lymphoma (CTCL). Malignant CD4+ T cells have been found to adopt the T-regulatory (Treg) cell phenotype and function. We present the case of a 66-year-old man diagnosed with mycosis fungoides that was progressing from the plaque to the tumor stage. The histopathological examinations showed that the Langerhans cell (LC) infiltration in the skin lesion of the tumor stage was greater than that in the patch/plaque stage; the tumor stage lesions resembled LC histiocytosis pathologically. The associations among LCs, apoptotic tumor cells, Treg CTCL cells, and relevant cytokines are complex. Treg CTCL cells produce the immunosuppressive cytokines interleukin-10 and transforming growth factor beta, which facilitate continuous recruitment of LCs and maintenance of long-term dendritic cell immaturity, thereby explaining the remarkable LC infiltration in the tumor stage samples from our patient. This phenomenon indicates that LCs accompanied by Treg CTCL cells may play an important synergistic role in the tumor progression. The development of immunotherapy directed against Treg CTCL cells and LCs overproduction and other immunosuppressive cytokines may be a potent useful adjuvant and worthy of further investigation

    Fabrication of Wireless Micro Pressure Sensor Using the CMOS Process

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    In this study, we fabricated a wireless micro FET (field effect transistor) pressure sensor based on the commercial CMOS (complementary metal oxide semiconductor) process and a post-process. The wireless micro pressure sensor is composed of a FET pressure sensor, an oscillator, an amplifier and an antenna. The oscillator is adopted to generate an ac signal, and the amplifier is used to amplify the sensing signal of the pressure sensor. The antenna is utilized to transmit the output voltage of the pressure sensor to a receiver. The pressure sensor is constructed by 16 sensing cells in parallel. Each sensing cell contains an MOS (metal oxide semiconductor) and a suspended membrane, which the gate of the MOS is the suspended membrane. The post-process employs etchants to etch the sacrificial layers in the pressure sensor for releasing the suspended membranes, and a LPCVD (low pressure chemical vapor deposition) parylene is adopted to seal the etch holes in the pressure. Experimental results show that the pressure sensor has a sensitivity of 0.08 mV/kPa in the pressure range of 0ā€“500 kPa and a wireless transmission distance of 10 cm

    Dynamics of HBV cccDNA expression and transcription in different cell growth phase

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    <p>Abstract</p> <p>Background</p> <p>The covalently closed-circular DNA (cccDNA) of hepatitis B virus (HBV) is associated with viral persistence in HBV-infected hepatocytes. However, the regulation of cccDNA and its transcription in the host cells at different growth stages is not well understood.</p> <p>Methods</p> <p>We took advantages of a stably HBV-producing cell line, 1.3ES2, and examine the dynamic changes of HBV cccDNA, viral transcripts, and viral replication intermediates in different cellular growth stages.</p> <p>Results</p> <p>In this study, we showed that cccDNA increased suddenly in the initial proliferation phase of cell growth, probably attributable to its nuclear replenishment by intracellular nucleocapsids. The amount of cccDNA then decreased dramatically in the cells during their exponential proliferation similar to the loss of extrachromosomal plasmid DNA during cell division, after which it accumulated gradually while the host cells grew to confluency. We found that cccDNA was reduced in dividing cells and could be removed when proliferating cells were subjected to long term of lamivudine (3TC) treatment. The amounts of viral replicative intermediates were rapidly reduced in these proliferating cells and were significantly increased after cells reaching confluency. The expression levels of viral transcripts were increased in parallel with the elevated expression of hepatic transcription factors (HNF4Ī±, CEBPĪ±, PPARĪ±, etc.) during cell growth confluency. The HBV transcripts were transcribed from both integrated viral genome and cccDNA, however the transcriptional abilities of cccDNA was less efficient then that from integrated viral genome in all cell growth stages. We also noted increases in the accumulation of intracellular viral particles and the secretion of mature virions as the cells reached confluency and ceased to grow.</p> <p>Conclusions</p> <p>Based on the dynamics of HBV replication, we propose that HBV replication is modulated differently in the different stages of cell growth, and can be divided into three phases (initial proliferation phase, exponential proliferation phase and growth confluency phase) according to the cell growth curve. The regulation of cccDNA in different cell growth phase and its importance regarding HBV replication are discussed.</p
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