1,245 research outputs found
Notes on Two Deep-Water Calanoids (Aetideopsis rostrata and Neoscolecithrix farrani) from Lancaster Sound
Two unusual calanoid copepods were collected in deep-water samples from eastern Lancaster Sound. The hitherto unknown male of Aetideopsis rostrata is described and the first record of Neoscolecithrix farrani from the western North Atlantic is reported.Key words: Canadian Arctic, zooplankton, Calanoida, morphology, distributio
Concept and Feasibility of One-Embedded System Payload Including Baseband Communication
Traditional approach of payload design develops modules separately such as control, compression and communication. Due to increasing demand of shorter development cycles and lower cost, we shall develop a highly adaptive approach for payload implementation so that we can update it in a short time according to the need of a new mission. Besides, the optimization of payload performance and communication link together becomes possible. Based on these, we propose a âone-embedded systemâ payload approach. All the control, file management, processing such as compression, and communications are implemented in one built-in embedded system. In other words, after the sensor signal is converted as digital data (after ADC, analog-to-digital-converter), the data gets into the proposed embedded system. And the system âdoes everythingâ and then outputs data to DAC (digital-to-analog-converter) and then transmitted it in analog form. The proposed embedded system includes a FPGA implementing a processor IP. Due to the programmable characteristic of FPGA, hardware interfaces can be adjusted quickly according to various mission requirements. Besides, because of the flexibility and adaptability of software, code can be updated to optimize performance according to various tasks during flight. In this work, we provide concept, guideline of optimization, structure, feasibility, benefits and risks of one-embedded system payload approach. An example of implementation for optical remotes sensing payload including interfaces will be investigated
Nanometer gaps by feedback-controlled electromigration
Nanometer-sized gap (or nanogap) is one of the most fundamental devices in the nanotechnology field. Park et. al., first proposed the open-circuit electromigration method to fabricate nanogaps, but the process is only repeatable if Au film is thinner than 20 nm. To overcome these drawbacks, we develop the feedback-controlled electromigration process and find that not only repeatable nanogaps can be created in thicker film (up to 120 nm or thicker in our experiments), but superior gap size control and topology are obtained. Moreover, we develop two new approaches to make free-standing nanogaps. The tunneling current between the nanogap electrodes was used to demonstrate a sensitive pressure and/or temperature sensor. Finally, we also develop a simple thermal-expansion method to measure the gap size without needing delicate instrument
Characteristics of virtual unipolar electrograms for detecting isthmus block during radiofrequency ablation of typical atrial flutter
AbstractObjectivesThe purpose of this study was to investigate the characteristics of the second component of local virtual unipolar electrograms recorded at the ablation line during coronary sinus (CS) pacing after radiofrequency ablation (RFA) of the cavotricuspid isthmus (CTI) for typical atrial flutter (AFL).BackgroundRadiofrequency ablation of the CTI can produce local double potentials at the ablation line. The second component of unipolar electrograms represents the approaching wavefront in the right atrium opposite the pacing site. We hypothesized that the morphologic characteristics of the second component of double potentials would be useful in detecting complete CTI block.MethodsRadiofrequency ablation of the CTI was performed in 52 patients (males = 37, females = 15, 62 ± 12 years) with typical AFL. The noncontact mapping system (Ensite 3000, Endocardial Solutions, St. Paul, Minnesota) was used to guide RFA. Virtual unipolar electrograms along the ablation line during CS pacing after RFA were analyzed. Complete or incomplete CTI block was confirmed by the activation sequence on the halo catheter and noncontact mapping.ResultsThree groups were classified after ablation. Group I (n = 37) had complete bidirectional CTI block. During CS pacing, the second component of unipolar electrograms showed an R or Rs pattern. Group II (n = 12) had incomplete CTI block. The second component of unipolar electrograms showed an rS pattern. Group III (n = 3) had complete CTI block with transcristal conduction. The second component of unipolar electrograms showed an rSR pattern.ConclusionsA predominant R-wave pattern in the second component of unipolar double potentials at the ablation line indicates complete CTI block, even in the presence of transcristal conduction
Successful treatment of methemoglobinemia in an elderly couple with severe cyanosis: two case reports
INTRODUCTION: Methemoglobinemia should be considered in all cyanotic patients who remain unresponsive to oxygen therapy. Rapid diagnosis is very important in emergency cases. Here, we present the cases of two patients, a married couple, admitted to our hospital with methemoglobinemia after exposure to sodium nitrite. CASE PRESENTATION: Two patients, a married couple, presented with methemoglobinemia. The 72-year-old Taiwanese man and 68-year-old Taiwanese woman were referred to our hospital with dizziness and tachypnea. On examination, their mucous membranes were cyanotic, and their blood samples showed the classic âchocolate brownâ appearance. The man also reported having experienced twitching of his right arm for a few minutes before arrival at the hospital. The symptoms of both patients failed to improve in response to supplemental oxygen delivered via oxygen masks, although the arterial blood gas data of these patients were normal and their pulse oximetry showed oxyhemoglobin levels of approximately 85%. A carbon monoxide-oximeter showed that the manâs methemoglobin concentration was 48.3%, and the womanâs was 36.4%. Methylene blue (100mg) was administered intravenously to both patients, and their symptoms improved dramatically. They were admitted to the intensive care unit and discharged three days later, without neurological sequelae. CONCLUSION: Severe methemoglobinemia is a life-threatening condition and, if untreated, may result in death. Early diagnosis and appropriate antidotal treatment are crucial in treating this emergency situation
Nanometer gaps by feedback-controlled electromigration
Nanometer-sized gap (or nanogap) is one of the most fundamental devices in the nanotechnology field. Park et. al., first proposed the open-circuit electromigration method to fabricate nanogaps, but the process is only repeatable if Au film is thinner than 20 nm. To overcome these drawbacks, we develop the feedback-controlled electromigration process and find that not only repeatable nanogaps can be created in thicker film (up to 120 nm or thicker in our experiments), but superior gap size control and topology are obtained. Moreover, we develop two new approaches to make free-standing nanogaps. The tunneling current between the nanogap electrodes was used to demonstrate a sensitive pressure and/or temperature sensor. Finally, we also develop a simple thermal-expansion method to measure the gap size without needing delicate instrument
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Efficient Prodrug Activator Gene Therapy by Retroviral Replicating Vectors Prolongs Survival in an Immune-Competent Intracerebral Glioma Model.
Prodrug activator gene therapy mediated by murine leukemia virus (MLV)-based retroviral replicating vectors (RRV) was previously shown to be highly effective in killing glioma cells both in culture and in vivo. To avoid receptor interference and enable dual vector co-infection with MLV-RRV, we have developed another RRV based on gibbon ape leukemia virus (GALV) that also shows robust replicative spread in a wide variety of tumor cells. We evaluated the potential of GALV-based RRV as a cancer therapeutic agent by incorporating yeast cytosine deaminase (CD) and E. coli nitroreductase (NTR) prodrug activator genes into the vector. The expression of CD and NTR genes from GALV-RRV achieved highly efficient delivery of these prodrug activator genes to RG-2 glioma cells, resulting in enhanced cytotoxicity after administering their respective prodrugs 5-fluorocytosine and CB1954 in vitro. In an immune-competent intracerebral RG-2 glioma model, GALV-mediated CD and NTR gene therapy both significantly suppressed tumor growth with CB1954 administration after a single injection of vector supernatant. However, NTR showed greater potency than CD, with control animals receiving GALV-NTR vector alone (i.e., without CB1954 prodrug) showing extensive tumor growth with a median survival time of 17.5 days, while animals receiving GALV-NTR and CB1954 showed significantly prolonged survival with a median survival time of 30 days. In conclusion, GALV-RRV enabled high-efficiency gene transfer and persistent expression of NTR, resulting in efficient cell killing, suppression of tumor growth, and prolonged survival upon CB1954 administration. This validates the use of therapeutic strategies employing this prodrug activator gene to arm GALV-RRV, and opens the door to the possibility of future combination gene therapy with CD-armed MLV-RRV, as the latter vector is currently being evaluated in clinical trials
Implementing Coastal Inundation Data with an Integrated Wind Wave Model and Hydrological Watershed Simulations
Coastal inundation due to wave overtopping coastal structures and storm surges often causes serious damage and danger to the population of Taiwan. Ascertaining the areas that are prone to coastal inundation is essential to provide countermeasures for mitigating the problem. Simulations without precipitation are examined in this study since overtopping has been determined to be a controlling factor in coastal flooding. We present scenarios for the simulation of coastal flooding with a unified wind wave and hydrological watershed model. The eastern coastal areas in Taiwan are selected as the study area. Simulations show that the resulting waves and tidal levels, generated by the Rankin-Vortex model and wind wave calculations, can be successfully obtained from the input data during wave overtopping simulations. A watershed model, WASH123D, was then employed for surface routing. The simulations indicate that the low-lying Yilan River and Dezikou Stream drainage systems were among the primary areas subject to inundation. Extensive inundation along both sides of the river banks was obtained in the case of extreme overtopping events. Coastal inundation could occur between the estuary of the Meilun Stream and most of the Nan-Bai-Bin areas in Hualien City. Calculations showed that more croplands flooded than did residential regions. No further damage to the upland of Hualien City was identified. The remaining study sites, Sinchen Township, Taitung City and Taimali Township, would only be slightly affected by seawater run-ups. Inundations caused by overtopping under extreme circumstances only affected the coast with almost trifling influence inland
Acute Paraparesis Caused by a Giant Cell Tumor of the Thoracic Spine
AbstractGiant cell tumor (GCT) is a benign but locally aggressive skeletal neoplasm of young adults. GCT located in the spine is relatively rare and may need a combination of surgical and adjunctive therapies. Here we present a patient who had intermittent thoracic back pain for two weeks and experienced an acute episode of decreased muscle power of both lower limbs. Magnetic resonance (MR) imaging examinations of the thoracic spine revealed that the patient had severe spinal canal compression caused by pathological fracture due to a tumor within the seventh thoracic vertebra. She underwent an emergent surgical intervention for total removal of the tumor and spinal reconstruction with autologous rib grafts and instruments. Postoperatively, the patient made an uneventful recovery of muscle power of bilateral lower limbs. She subsequently received adjuvant radiotherapy. In a follow-up period of 36 months, the patient had no clinical or radiological evidence of tumor recurrence. Even though spinal location for GCT is a rare event, it should be included in the differential diagnosis in patients with osteolytic lesions or pathological fractures of the vertebra, especially in young female patients sustaining no trauma who had a clinical history of persistent low back pain
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