928 research outputs found

    The Effect of Feedback Types on Academic Achievement in Learning with Computerized Tests

    Get PDF
    An earlier version of this article was presented at the Pacific Rim Objective Measurement Symposium (PROMS 2006), The Hong Kong Institute of Education, Tai Po, Hong Kong, June 27th-29th, 2006The purpose of this study was to show the effect of back types (standardized type vs. differentiated type) on academic achievement in learning with computerized tests. For this study, two computerized learning programs with different feedback types were developed with HTML, PHP, and SQL computer languages, and a science achievement test was developed by two high school science teachers. The science achievement tests content and face validity were examined by 5 high school science teachers and its Cronbach's alpha coefficient was 0.82. The research subjects were 137 10th graders from 4 classrooms within 2 high schools in Korea. They were divided into two groups. One group took a 3-weeks learning program with computerized a test using standardized type feedbacks. The other group also took a 3-week learning program with a computerized test using differentiated type feedbacks. After learning with computerized tests was implemented, a science achievement test was administered to all students belonging to both groups. The result of data analysis with ANCOVA was that differentiated type feedback was more effective than the standardized type feedback for learning with computerized test (F=8.98, p<0.01)

    Identification of replicative senescence-associated genes in human umbilical vein endothelial cells by an annealing control primer system

    Get PDF
    Cellular senescence is regulated by specific genes in many organisms. The identification and functional analysis of senescence-associated genes could provide valuable insights into the senescence process. Here, we employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method that involves annealing control primers (ACPs) to identify genes that are differentially expressed in human umbilical endothelial cells during replicative senescence. Using 120 ACPs, we identified 31 differentially expressed genes (DEGs). Basic local alignment search tool (BLAST) search revealed 29 known genes and two unknown genes. Expression levels of the 29 known genes were confirmed by real-time quantitative RT-RCR and by Western blotting for eight of these genes. CD9 antigen, MHC class I chain-related sequence A (MICA) and cell division cycle 37 homolog (CDC37) were up-regulated, and bone morphogenetic protein 4 (BMP4), dickkopf-1 (DKK1), and transcription factor 7-like 1 (TCF7L1) were down-regulated in old cells. Treatment with recombinant human MICA caused a decrease in cell proliferation and an increase in senescence-associated beta-galactosidase staining. Further analysis of differentially expressed genes may provide insights into the molecular basis of replicative senescence and vascular diseases associated with cellular senescence

    Large clusters and hollow microfibers by multicomponent self-assembly of citrate stabilized gold nanoparticles with temperature-responsive amphiphilic dendrimers

    Get PDF
    Gold clusters with controlled sizes have been prepared by controlled self-assembly of citrate stabilized gold nanoparticles (AuNPs) with temperature-responsive luminescent amphiphilic dendrimers (Den 40) of oligo(p-phenylene vinylene) core branches and oligo(ethylene oxide) terminal chains. The shape and size of the resultant gold clusters depend strongly on the molar ratio of Den 40 to AuNPs. These gold clusters can further assemble into hollow microfibers decorated with AuNPs, which can be used as a promising substrate for surface enhanced Raman spectroscopy (SERS). The formation of spherical gold clusters and hollow microfibers simply by self-assembly of AuNPs and luminescent amphiphilic dendrimers (Den 40) could not only provide some useful insights for producing multifunctional materials via multicomponent self-assembly but also offer promise for potential applications of the self-assemblies in many systems, such as SERS and stimuli-responsive sensors.close2

    Cause and Management of Patients With Failed Endonasal Dacryocystorhinostomy

    Get PDF
    Objectives Endonasal dacryocystorhinostomy (DCR) is a well-established treatment method in patients with nasolacrimal duct obstruction. However, there are a few reports about the overall management of failed endonasal DCR. We investigated the causes and management strategies of failed endonasal DCR. Methods This retrospective review included 61 patients (61 eyes) who had undergone revision surgery by the same surgeon after failed endonasal DCR between January 2008 and December 2012. The appropriate revision method was determined after analysis of the etiology of failure by the fluorescein dye disappearance test, nasal endoscopy, lacrimal irrigation, and probing. The criteria for success of the revision surgery were defined by the passage of fluid without resistance upon lacrimal irrigation and normalization of the tear meniscus height. Results The mean duration between the primary endonasal DCR and revision surgery was 15.3 months. The average follow-up period after revision surgery was 12.2 months. The most common cause of endoscopic revision surgery was membranous obstruction. Endoscopic revision surgery was performed in 48 patients, while lacrimal silicone tube intubation under endoscopy was performed in 13 patients. The most common indication for lacrimal silicone tube intubation was functional epiphora. The overall success rate of the revision surgery was 89%. Conclusion The most common cause of failed endonasal DCR was membranous obstruction. When patients with failed endonasal DCR presented at the clinic, it is important to identify the cause of the failure. Revision surgery could increase the final success rate of endonasal DCR

    Tin doped indium oxide core-TiO <inf>2</inf> shell nanowires on stainless steel mesh for flexible photoelectrochemical cells

    Get PDF
    Photoanode architecture is built on highly conductive tin doped indium oxide (ITO) nanowires (NWs) on a flexible stainless steel mesh (SSM). ITO nanowires were coated with the atomic layer deposition grown TiO 2 layer and the photoelectrochemical performance of the stainless steel mesh based photoanode were examined as a function of wire-length and shell-thickness. The photoanode consisting of 20 m-long nanowire core and 36 nm thick shell increased the photocurrent of the testing cell by 4 times, compared to a reference cell. This enhanced photochemical activity is attributed to higher light harvesting efficiency of nanowire arrays and suppressed charge recombination of core-shell structure. © 2012 American Institute of Physics

    Patterns of inflammatory immune responses in patients with septic shock receiving vitamin C, hydrocortisone, and thiamine: clustering analysis in Korea

    Get PDF
    Background Sepsis is characterized by heterogeneous immune responses that may evolve during the course of illness. This study identified inflammatory immune responses in septic patients receiving vitamin C, hydrocortisone, and thiamine. Methods This was a single-center, post-hoc analysis of 95 patients with septic shock who received the vitamin C protocol. Blood samples were drawn on days 1–2, 3–4, and 6–8 after shock onset. Group-based multi-trajectory modeling was used to identify immune trajectory groups. Results The median age was 78 years (interquartile range, 70–84 years), and 56% were male. Clustering analysis identified group 1 (n=41), which was characterized by lower interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-10 levels, and these levels remained stationary or mildly increased until day 7. Conversely, group 2 (n=54) expressed initially higher IL-6, TNF-α, and IL-10 levels that decreased rapidly by day 4. There was a nonsignificant increase in lymphocyte count and a decrease in C-reactive protein level until day 7 in group 2. The intensive care unit mortality rate was significantly lower in group 2 (39.0% vs. 18.5%, P=0.03). Group 2 also had a significantly higher decrease in the mean (standard deviation) vasopressor dose (norepinephrine equivalent: –0.09±0.16 μg/kg/min vs. –0.23±0.31 μg/kg/min, P<0.001) and Sequential Organ Failure Assessment score (0±5 vs. –4±3, P=0.002) between days 1 and 4. Conclusions There may be different subphenotypes in septic patients receiving the vitamin C protocol

    The Effects of Changing from Isoflurane to Desflurane on the Recovery Profile during the Latter Part of Anesthesia

    Get PDF
    It is not known whether changing from isoflurane to desflurane during the latter part of anesthesia shows early emergence and recovery in long surgery. We therefore evaluated the effects of changing isoflurane to desflurane on emergence and recovery. Eighty-two patients were randomly assigned to receive isoflurane (Group I) or desflurane (Group D) or to change from isoflurane to desflurane anesthesia (Group X). At the point when there was an hour until the operation would end, isoflurane was replaced with 1 MAC of desflurane in Group X, and isoflurane and desflurane were maintained at 1 MAC in Groups I and D. When the operation ended, we compared the emergence and recovery characteristics among the 3 groups. Compared with Group I, Group X showed faster emergence and recovery. Group X and Group D showed similar emergence and recovery. In conclusion, changing isoflurane to desflurane during the latter part of anesthesia improves emergence and recovery

    Radiofrequency Ablation of Benign Thyroid Nodules and Recurrent Thyroid Cancers: Consensus Statement and Recommendations

    Get PDF
    Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus
    corecore