2,146 research outputs found

    A Patterned Single Layer Graphene Resistance Temperature Sensor

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    Micro-fabricated single-layer graphenes (SLGs) on a silicon dioxide (SiO2)/Si substrate, a silicon nitride (SiN) membrane, and a suspended architecture are presented for their use as temperature sensors. These graphene temperature sensors act as resistance temperature detectors, showing a quadratic dependence of resistance on the temperature in a range between 283 K and 303 K. The observed resistance change of the graphene temperature sensors are explained by the temperature dependent electron mobility relationship (~T−4) and electron-phonon scattering. By analyzing the transient response of the SLG temperature sensors on different substrates, it is found that the graphene sensor on the SiN membrane shows the highest sensitivity due to low thermal mass, while the sensor on SiO2/Si reveals the lowest one. Also, the graphene on the SiN membrane reveals not only the fastest response, but also better mechanical stability compared to the suspended graphene sensor. Therefore, the presented results show that the temperature sensors based on SLG with an extremely low thermal mass can be used in various applications requiring high sensitivity and fast operation

    Antibacterial and synergistic effects of Nardostachytis rhizoma extracts on methicillin-resistant Staphylococcus aureus

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    Methicillin-resistant Staphylococcus aureus (MRSA) is a serious clinical problem worldwide. Few new drugs are available against MRSA, because it has the ability to acquire resistance to most antibiotics which consequently increases the cost of medication. In the present study, the antibacterial activity of Nardostachytis rhizoma was investigated. The most effective method is to develop antibiotics from the natural products without having any toxic or side effects. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. The use of two drugs in combination is a good alternative to slow the process of developing drug resistance and to restore the effectiveness of drugs that are no longer prescribed. Combination therapy is the most commonly recommended empirical treatment for bacterial infections in intensive care units, where monotherapy may not be effective against all potential pathogens, and for preventing the emergence of resistant. Five clinical isolates (MRSA) were obtained from five different patients at Wonkwang University Hospital (Iksan, South Korea). The other two strains were S. aureus ATCC 33591 (methicillin-resistant strain) and S. aureus ATCC 25923 (methicillin-susceptible strain). Antibacterial activity (minimal inhibitory concentrations, MICs) was determined by broth dilution method, disc diffusion method, MTT test and checkerboard dilution test. Antimicrobial activity of n-hexane fraction of N. rhizoma was significant. Against the seven strains, the disc diffusion test was in the range of 14 to 18 mm and had a MICs ranging from 31.25 to 125 ìg/ml. FICI values for n-hexane fraction (HFL) of N. rhizome + ampicillin (AM) and HFL + oxacillin (OX) were 0.1875 and 0.078125-0.09375, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA and MSSA.Key words: Nardostachytis rhizoma, synergism, antibacterial, methicillin-resistant Staphylococcus aureus (MRSA)

    Enhancement of phase separation in the InGaN layer for self-assembled In-rich quantum dots

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    The enhancement of phase separation in the InGaN layer grown on a GaN layer with a rough surface was investigated for the formation of self-assembled In-rich quantum dots(QDs) in the InGaN layer. Transmission electron microscopy images showed that In-rich QDs with a size of 2–5 nm were formed even in an InGaN layer with a low indium content, and a layer thickness less than the critical thickness. The room-temperature photoluminescence(PL) spectrum of this layer showed emission peaks corresponding to In-rich QDs. The temperature-dependent PL spectra showed dominant peak shifts to the lower energy side, indicating that the self-assembled In-rich QDs are formed in the InGaN layer grown on a rough GaNsurface and that the carriers are localized in In-rich QDs

    Extracellular matrixes and neuroinflammation

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    The extracellular matrix is a critical component of every human tissue. ECM not only functions as a structural component but also regulates a variety of cellular processes such as cell migration, differentiation, proliferation, and cell death. In addition, current studies suggest that ECM is critical for the pathophysiology of various human diseases. ECM is composed of diverse components including several proteins and polysaccharide chains such as chondroitin sulfate, heparan sulfate, and hyaluronic acid. Each component of ECM exerts its own functions in cellular and pathophysiological processes. One of the interesting recent findings is that ECM is involved in inflammatory responses in various human tissues. In this review, we summarized the known functions of ECM in neuroinflammation after acute injury and chronic inflammatory diseases of the central nerve systems

    Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: A role in organ preservation

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    Background/Aims: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. Methods: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. Results: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). Conclusions: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.

    Safe and cost-effective method for application of liquid ethyl formate (FumateTM) as a methyl bromide alternative for perishable commodities: Poster

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    The cylinderized liquid ethyl formate (EF) formulated with CO2 is one of the great potential fumigants to replace methyl bromide (MeBr) for fresh fruit. However, it is too expensive to adapt commercial practices, and also involves work place safety issue including handling of heavy cylinders as well as restrict emission of CO2, particularly for use in large scale commercial fumigationw. Therefore, it is urgently needed to develop environmental friendly, safe for workers and cost-effective alternative method for application of liquid ethyl formate as a MeBr alternative for perishable commodities. Recently, the environmentally friendly, cost-effective and practically safe use of liquid EF (FumateTM, registered name) with nitrogen gas has been developed and commercialized in Republic of Korea and Australia. The new technology for application of liquid EF is 100 times safer than MeBr in terms of threshold values (EF, TLV = 100 ppm). Ethyl formate is known as food additive and naturally occurred substances as well as a non-ozone depletion chemical. In this report, we demonstrate the liquid EF application technology that offers a clean environment (no ozone depletions and CO2 emissions), safe to fumigators and related workers and practically cost-effective technology to fumigation industry.The cylinderized liquid ethyl formate (EF) formulated with CO2 is one of the great potential fumigants to replace methyl bromide (MeBr) for fresh fruit. However, it is too expensive to adapt commercial practices, and also involves work place safety issue including handling of heavy cylinders as well as restrict emission of CO2, particularly for use in large scale commercial fumigationw. Therefore, it is urgently needed to develop environmental friendly, safe for workers and cost-effective alternative method for application of liquid ethyl formate as a MeBr alternative for perishable commodities. Recently, the environmentally friendly, cost-effective and practically safe use of liquid EF (FumateTM, registered name) with nitrogen gas has been developed and commercialized in Republic of Korea and Australia. The new technology for application of liquid EF is 100 times safer than MeBr in terms of threshold values (EF, TLV = 100 ppm). Ethyl formate is known as food additive and naturally occurred substances as well as a non-ozone depletion chemical. In this report, we demonstrate the liquid EF application technology that offers a clean environment (no ozone depletions and CO2 emissions), safe to fumigators and related workers and practically cost-effective technology to fumigation industry

    GarlicESTdb: an online database and mining tool for garlic EST sequences

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    <p>Abstract</p> <p>Background</p> <p><it>Allium sativum</it>., commonly known as garlic, is a species in the onion genus (<it>Allium</it>), which is a large and diverse one containing over 1,250 species. Its close relatives include chives, onion, leek and shallot. Garlic has been used throughout recorded history for culinary, medicinal use and health benefits. Currently, the interest in garlic is highly increasing due to nutritional and pharmaceutical value including high blood pressure and cholesterol, atherosclerosis and cancer. For all that, there are no comprehensive databases available for Expressed Sequence Tags(EST) of garlic for gene discovery and future efforts of genome annotation. That is why we developed a new garlic database and applications to enable comprehensive analysis of garlic gene expression.</p> <p>Description</p> <p>GarlicESTdb is an integrated database and mining tool for large-scale garlic (<it>Allium sativum</it>) EST sequencing. A total of 21,595 ESTs collected from an in-house cDNA library were used to construct the database. The analysis pipeline is an automated system written in JAVA and consists of the following components: automatic preprocessing of EST reads, assembly of raw sequences, annotation of the assembled sequences, storage of the analyzed information into MySQL databases, and graphic display of all processed data. A web application was implemented with the latest J2EE (Java 2 Platform Enterprise Edition) software technology (JSP/EJB/JavaServlet) for browsing and querying the database, for creation of dynamic web pages on the client side, and for mapping annotated enzymes to KEGG pathways, the AJAX framework was also used partially. The online resources, such as putative annotation, single nucleotide polymorphisms (SNP) and tandem repeat data sets, can be searched by text, explored on the website, searched using BLAST, and downloaded. To archive more significant BLAST results, a curation system was introduced with which biologists can easily edit best-hit annotation information for others to view. The GarlicESTdb web application is freely available at <url>http://garlicdb.kribb.re.kr</url>.</p> <p>Conclusion</p> <p>GarlicESTdb is the first incorporated online information database of EST sequences isolated from garlic that can be freely accessed and downloaded. It has many useful features for interactive mining of EST contigs and datasets from each library, including curation of annotated information, expression profiling, information retrieval, and summary of statistics of functional annotation. Consequently, the development of GarlicESTdb will provide a crucial contribution to biologists for data-mining and more efficient experimental studies.</p

    Multiple cerebral infarction and paradoxical air embolism during hepatectomy using the Cavitron Ultrasonic Surgical Aspirator -A case report-

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    A venous air embolism and paradoxical air embolism (PAE) are serious complications in patients undergoing a hepatectomy. We report a case of PAE and cerebral infarctions in a patient undergoing a hepatic resection using a Cavitron Ultrasonic Surgical Aspirator (CUSA®). A 65-year-old woman underwent a left lobe hepatectomy. During the middle phase of the liver resection with CUSA®, there was a sudden decrease in arterial blood pressure, end-tidal carbon dioxide and SpO2. With resuscitation, intraoperative ultrasonography revealed massive air emboli in both her left and right heart, which lasted for 40 min. The hepatectomy was completed after the disappearance of the air emboli from her heart. After surgery, her mental status was stuporous. The brain CT and MRI revealed multiple acute cerebral infarctions. Finally, she died from septic shock. This case highlights the need for anesthetists and surgeons to be aware of the potential for CUSA®-related massive PAE
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