2,690 research outputs found

    Factors Affecting the Extrusion Rate of Ventilation Tubes

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    ObjectivesThe objective of this study was to determine the various factors that affect the extrusion rate of ventilation tubes (VTs), including the nature of the middle ear effusion.MethodsA retrospective chart review of 82 pediatric patients (177 ears) who received VT insertion surgery under general anesthesia was carried out to evaluate the relationship between various factors and the VT extrusion rate. The factors we analyzed included age, gender, the adenoid size, the amount and content of the middle ear effusion after myringotomy, bleeding events, associated adenoidectomy and the findings of the tympanic membrane status, the tympanometry and the audiometry of the air bone gap.ResultsThe mean extrusion time was 254 days (range, 11 to 809 days). The patients with no history of previous VT insertion had a longer extrusion time (mean, 279 days) than did the patients who had undergone previous VT insertion (mean, 203 days). The patients with serous effusion had the shortest extrusion time (mean, 190 days) as compared to those patients with glue (273 days) and pus (295 days) effusions. Other factors had no statistical significant relationship with the extrusion time.ConclusionThe mean VT extrusion time was 254 days. The VT extrusion time was significantly related to the characteristics of the middle ear effusion and a history of previous VT insertion. Thus, the nature of middle ear effusion can provide a clinical clue to predict the VT extrusion time

    Ultraviolet photodepletion spectroscopy of dibenzo-18-crown-6-ether complexes with alkali metal cations

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    Ultraviolet photodepletion spectra of dibenzo-18-crown-6-ether complexes with alkali metal cations (M+-DB18C6, M = Cs, Rb, K, Na, and Li) were obtained in the gas phase using electrospray ionization quadrupole ion-trap reflectron time-of-flight mass spectrometry. The spectra exhibited a few distinct absorption bands in the wavenumber region of 35450−37800 cm^(−1). The lowest-energy band was tentatively assigned to be the origin of the S_0-S_1 transition, and the second band to a vibronic transition arising from the “benzene breathing” mode in conjunction with symmetric or asymmetric stretching vibration of the bonds between the metal cation and the oxygen atoms in DB18C6. The red shifts of the origin bands were observed in the spectra as the size of the metal cation in M^+-DB18C6 increased from Li^+ to Cs^+. We suggested that these red shifts arose mainly from the decrease in the binding energies of larger-sized metal cations to DB18C6 at the electronic ground state. These size effects of the metal cations on the geometric and electronic structures, and the binding properties of the complexes at the S_0 and S_1 states were further elucidated by theoretical calculations using density functional and time-dependent density functional theories

    Phytosynthesis of Silver and Gold Nanoparticles Using the Hot Water Extract of Mixed Woodchip Powder and Their Antibacterial Efficacy

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    This study investigates the phytosynthesis, characterization, and antibacterial efficacy of silver and gold nanoparticles (NPs) produced using the hot water extract of mixed woodchip powder. The woodchip extract (WCE) was successfully used as both a reducing and stabilizing agent for the phytosynthesis of both crystalline metal NPs. The effects of different physicochemical factors affecting the formation of the metal NPs including reaction pH, concentration of the precursor metal salts, amount of WCE, and external energy input were evaluated. The characterization of the metal NPs was performed by transmission electron microscopy, selected area electron diffraction (SAED), energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) pattern analysis. In addition, the antibacterial efficacy of the phytosynthesized NPs was measured. The AgNPs showed clear antibacterial activity against four representative bacterial strains. However, the AuNPs did not exhibit bactericidal activity, probably due to their surface modifications and relatively large size. These results suggest that the phytosynthesis of the metal NPs using WCE is highly efficient, and its convenience makes it suitable for use in large-scale production

    New-type of Multi-purpose Standard Radon Chamber in South Korea

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    Radon is an inert and a radioactive gas which is colorless, tasteless and odorless. As the radon decay proceeds, and if DNA damage continues beyond repair capacity of cells in the human body, it can cause severe health problems such as lung cancer in the long-term. There is a tendency that those countries where legal restriction on radon is strict, various studies related to radon are under way. In South Korea, radon has been regulated under recommendation level. Even though there are about 3 standard radon chambers in Korea, they have not been in an active use because of lack of demand. Also, most of them are specialized in calibration of radon detectors only. Recently, Korean government started giving some attention to radon issue and supporting radon research fields. Thus, this study was carried out to develop a new type of radon chamber for multi-purpose such as 1) radon emission rate from natural and artificial radon sources; 2) calibration of radon detectors; 3) evaluation of radon mitigation efficiency. Keywords: Radon, Radon Chamber, Indoor Air Quality, Chamber Desig

    An Experiment of Game Promotion and Selling Using Twitter

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    — The combination of the internet, social media and mobile phones makes the social mobile game is becoming a huge market with high growth rates from year to year. This trend is attract the game developers/publisher vying to enter this game market including in Indonesia. In other hand, Twitter as one of social media has a major influence on consumer purchase decisions especially in social mobile games. Consumer seeking recommendation about game that they want to download based on their friend recommendation and content that their consume in social media before visit online store. As for Indonesia game developers most of their marketing activities were more to game gathering or events, there is little that effectively use social media as marketing channel. Social media adoption including twitter in Indonesia game developer is at stage of connectivity and proff of company existance. The purpose of this research is to know does using twitter as social media marketing have effect to influence consumer and download mobile game. In this research, experiment methodology was employed. Experiment was choosed because to have real insight about the effect of twitter as social media marketing in building games relationship with consumer and increase the number of game download. Stack The Stuff, game from PT. Nightspade was choosed as research object. The implementation using OASIS frawework as guidance. The results from the experiments in this research measured using Social Model Exposure-Engagement-Influence-Action from Don Bartholomew.Twitter as media marketing executed by carrying experiment 1 (15 August 2012 - 15 September 2012) with buzzing methods first, after it finish, followed by experiment 2 (22 September - 22 October 2012) with tweeting and offering method. Then, both experiment results compared to know which the better Twitter marketing method. The measurement using several tools, namely TweetLevel, Sprout Social, and downloads data. With confidence level 95%, our results suggested that twitter as media marketing with buzzing method have effect to increase game download and tweeting and offering method have effect to increase product engagement and influence in Twitter. Furthermore, in the end of research, there are recommendations to implement twitter as social media marketing for small-middle sized company like Indonesia game developer

    Impact of non-pharmaceutical interventions on the rate of respiratory viruses other than severe acute respiratory syndrome coronavirus 2 in the coronavirus disease 2019 pandemic

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    Purpose We aimed to evaluate the impact of non-pharmaceutical interventions (NPIs) on the transmission of respiratory viruses other than severe acute respiratory syndrome coronavirus 2 among children during the coronavirus disease 2019 pandemic. Methods We analyzed the clinical and polymerase chain reaction (PCR) findings using electronic medical records of children (< 18 years) with fever or respiratory symptoms who were hospitalized via the emergency department of Wonkwang University Hospital (Iksan, Korea), from March 2018 through December 2021. The children were divided into before and after groups based on the hospitalization date relative to February 2020, starting point of the implementation of NPIs. PCR was performed using nasopharyngeal swab samples. Between the 2 groups, we compared age, sex, length of hospital stay, and PCR findings. Results The before and after groups consisted of 3,160 and 989, respectively, showing a 68.7% decrease in the number of children undergoing PCRs after the implantation of NPIs. The after group showed higher median values of the age and length of hospital stay than the before group (Ps < 0.001). A 76.9% decrease was noted in the number of children having PCR positivities (from 1,101 [34.8%] to 254 [25.7%]; P < 0.001). Among detected viruses, an increase in the proportion was noted only in human bocavirus (from 81 [2.6%] to 54 [5.5%]; P < 0.001). In contrast, significant decreases in the proportions were found in adenovirus, enterovirus, influenza A and B, respiratory syncytial viruses A and B, human coronaviruses (229E, NL63, and OC43) and human metapneumovirus. Conclusion NPIs may be effective in reducing the transmission of respiratory viruses other than severe acute respiratory syndrome coronavirus 2 among children during the pandemic

    Iron, Iodine and Selenium Effects on Quality, Shelf Life and Microbial Activity of Cherry Tomatoes

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    Tomatoes have high nutritional and economical value and its deterioration start after harvest. They need proper treatments to increase and maintain quality as well as shelf life. The objective of this study was to determine the effect of iron, iodine and selenium on quality, shelf life and microbial activity of cherry tomatoes. Iron (1 mg/L), iodine (1 mg/L) and selenium (1 mg/L) were supplied with nutrient solution for five weeks prior to harvest. Then, cherry tomatoes were stored at  5 °C to assess quality, shelf life and microbial activity. The highest Ca content (p &lt; 0.05) revealed in selenium-treated cherry tomatoes. Lower respiration and ethylene production were showed in selenium-treated cherry tomatoes both harvest time and after storage compared with iron and iodine treatments. At harvest time and after storage, the respiration were 1.29 (p &lt; 0.05) and 0.62 mL/kg/hr (p &lt; 0.01), respectively in selenium-treated cherry tomatoes. Moreover at harvest time and after storage in selenium-treated cherry tomatoes, the ethylene production was 2.11 and 0.87 μL/kg/hr (p &lt; 0.01), respectively. The lowest fresh weight loss, the longest shelf life (p &lt; 0.01), the least fungal incidence rate and microbial activities were found in selenium-treated cherry tomatoes. The longest shelf life of selenium-treated cherry tomatoeswas 22 days. Selenium-treated cherry tomatoes’ firmness increased (16.82N) at harvest time (p &lt; 0.05) and it was significantly retained (12.70N) after storage (p &lt; 0.01). Color development and lycopene content were more suppressed by selenium treatment after storage than iron and iodine treatments. Titratable acidity, vitamin C and soluble solids increased in selenium-treated cherry tomatoes after storage. Based on results, selenium-treated cherry tomatoes have significant potential to increase and maintain quality and shelf life
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