1,050 research outputs found

    The Psychology of Rewards in Digital Game-Based Learning: A Comprehensive Review

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    A significantly accelerated speed in the growth and acceptance of new technology has been observed in recent decades. This rapid technological transition has affected almost every economy, environment, culture, and education. The rapid technological evolution has led to the frequent use of Digital Game-Based Learning (DGBL), where users learn and play simultaneously. DGBL has been implemented to supplement formal classroom lessons. Despite the extensive use of DGBL and other implementation methodologies, no study has yet synthesised the use of the "reward system" and its associated components. This study reviewed over fifty scientific publications on the forms of rewards in DGBL and their effects on learners, published between 2000 and 2021

    Severe Paradoxical Reaction Requiring Tracheostomy in a Human Immunodeficiency Virus (HIV)-negative Patient with Cervical Lymph Node Tuberculosis

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    During drug treatment of tuberculous lymphadenitis, paradoxical response (PR) may occasionally occur. Continued treatment or lymph node aspiration improves PR without severe sequelae. However, we report a case of severe PR in a patient with cervical lymph node tuberculosis causing airway obstruction due to retropharyngeal lymph node swelling during antituberculous treatment. Tracheostomy and drainage of the node were performed to secure the airway. Possible airway obstruction due to PR must be suspected when cervical lymph node tuberculosis involves the retropharyngeal lymph node

    Seizure After Local Anesthesia for Nasopharyngeal Angiofibroma

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    We report a young male patient who experienced seizure after local injection of 3 mL 2% lidocaine with epinephrine 1:200,000 around a recurrent nasal angiofibroma. After receiving 100% oxygen via mask and thiamylal sodium, the patient had no residual neurologic sequelae. Seizure immediately following the injection of local anesthetics in the nasal cavity is probably due to injection into venous or arterial circulation with retrograde flow to the brain circulation. Further imaging study or angiography should be done before head and neck surgeries, especially in such highly vascular neoplasm

    Merkel Cell Polyomavirus Small T Antigen Promotes Pro-Glycolytic Metabolic Perturbations Required for Transformation

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    An accurate analytic model describing the microscopic mechanism of high-harmonic generation (HHG) in solids is derived. Extensive first-principles simulations within a time-dependent density-functional framework corroborate the conclusions of the model. Our results reveal that (i) the emitted HHG spectra are highly anisotropic and laser-polarization dependent even for cubic crystals; (ii) the harmonic emission is enhanced by the inhomogeneity of the electron-nuclei potential; the yield is increased for heavier atoms; and (iii) the cutoff photon energy is driver-wavelength independent. Moreover, we show that it is possible to predict the laser polarization for optimal HHG in bulk crystals solely from the knowledge of their electronic band structure. Our results pave the way to better control and optimize HHG in solids by engineering their band structure

    Effects of Celecoxib and Nordihydroguaiaretic Acid on Puromycin Aminonucleoside-Induced Nephrosis in the Rat

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    The selective cyclooxygenase-2 (COX-2) and 5-lipoxygenase (LOX) inhibitors might inhibit prostaglandin synthesis and reduce proteinuria. The present study was designed to investigate the anti-proteinuric effects of nordihydroguaiaretic acid (NDGA) as compared with celecoxib in puromycin aminonucleoside (PAN) nephrosis rats. Fifty five male Sprague-Dawley rats were divided into 4 groups; A, normal control; B, PAN group; C, PAN+COX-2 inhibitor (celecoxib) group; and D, PAN+5-LOX inhibitor (NDGA) group. After induction of PAN nephrosis through repeated injections of PAN (7.5 and 15 mg/100 g body weight), rats were treated with celecoxib, NDGA, or vehicle for 2 weeks. Twenty four hour urine protein excretions were significantly lower in PAN+celecoxib and PAN+NDGA groups than in PAN group. Serum creatinine (SCr) concentrations and 24 hr urine creatinine clearances (CCr) were not significantly different in the four groups. Electron microscopy showed that podocyte morphology was changed after the induction of PAN nephrosis and was recovered after celecoxib or NDGA administration. Celecoxib significantly recovered the expressions of nephrin, CD2AP, COX-2, and TGF-β. NDGA also recovered TGF-β expression, but did not alter the expressions of nephrin, CD2AP and COX-2. The present study suggested that celecoxib and NDGA might effectively reduce proteinuria in nephrotic syndrome without impairing renal function

    Hypokalemia Promotes Late Phase 3 Early Afterdepolarization and Recurrent Ventricular Fibrillation During Isoproterenol Infusion in Langendorff Perfused Rabbit Ventricles

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    BACKGROUND Hypokalemia and sympathetic activation are commonly associated with electrical storm (ES) in normal and diseased hearts. The mechanisms remain unclear. OBJECTIVE To test the hypothesis that late phase 3 early afterdepolarization (EAD) induced by IKATP activation underlies the mechanisms of ES during isoproterenol infusion and hypokalemia. METHODS Intracellular calcium (Cai) and membrane voltage were optically mapped in 32 Langendorff-perfused normal rabbit hearts. RESULTS Repeated episodes of electrically-induced VF at baseline did not result in spontaneous VF (SVF). During isoproterenol infusion, SVF occurred in 1 of 15 hearts (7%) studied in normal extracellular potassium ([K+]o) (4.5 mmol/L), 3 of 8 hearts (38%) in 2.0 mmol/L [K+]o, 9 of 10 hearts (90%) in 1.5 mmol/L [K+]o, and 7 of 7 hearts (100%) in 1.0 mmol/L [K+]o (P<0.001). Optical mapping showed isoproterenol and hypokalemia enhanced Cai transient duration (CaiTD) and heterogeneously shortened action potential duration (APD) after defibrillation, leading to late phase 3 EAD and SVF. IKATP blocker (glibenclamide, 5 μmol/L) reversed the post-defibrillation APD shortening and suppressed recurrent SVF in all hearts studied despite no evidence of ischemia. Nifedipine reliably prevented recurrent VF when given before, but not after, the development of VF. IKr blocker (E-4031) and small conductance calcium activated potassium channel blocker (apamin) failed to prevent recurrent SVF. CONCLUSION Beta-adrenergic stimulation and concomitant hypokalemia could cause non-ischemic activation of IKATP, heterogeneous APD shortening and prolongation of CaiTD to provoke late phase 3 EAD, triggered activity and recurrent SVF. IKATP inhibition may be useful in managing ES during resistant hypokalemia

    Apamin-Sensitive Calcium-Activated Potassium Currents in Rabbit Ventricles with Chronic Myocardial Infarction

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    Introduction Apamin-sensitive small-conductance calcium-activated potassium current (IKAS) is increased in heart failure. It is unknown if myocardial infarction (MI) is also associated with an increase of IKAS. Methods and Results We performed Langendorff perfusion and optical mapping in 6 normal hearts and 10 hearts with chronic (5 weeks) MI. An additional 6 normal and 10 MI hearts were used for patch clamp studies. The infarct size was 25% [95% confidence interval, 20 to 31] and the left ventricular ejection fraction was 0.5 [0.46 to 0.54]. The rabbits did not have symptoms of heart failure. The action potential duration measured to 80% repolarization (APD80) in the peri-infarct zone (PZ) was150 [142 to 159] ms, significantly (p=0.01) shorter than in the normal ventricles (158 to 177] ms). The intracellular Ca transient duration was also shorter in the PZ (148 [139 to 157] ms) than in normal ventricles (168 [157 to 180] ms; P=0.017). Apamin prolonged the APD80 in PZ by 9.8 [5.5 to 14.1] %, which is greater than in normal ventricles (2.8 [1.3 to 4.3] %, p=0.006). Significant shortening of APD80 was observed at the cessation of rapid pacing in MI but not in normal ventricles. Apamin prevented postpacing APD80 shortening. Patch clamp studies showed that IKAS was significantly higher in the PZ cells (2.51 [1.55 to 3.47] pA/pF, N=17) than in the normal cells (1.08 [0.36 to 1.80] pA/pF, N=15, p=0.019). Conclusion We conclude that IKAS is increased in MI ventricles and contributes significantly to ventricular repolarization especially during tachycardia

    Silicon-containing dendritic tris-cyclometalated Ir(III) complex and its electrophosphorescence in a polymer host

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    In this paper, we present the synthesis and characterization of a new highly phosphorescent cyclometalated Ir(III) complex with a silane-based dendritic substituent. The Ir(III) complex showed 74 ± 3% of absolute phosphorescence quantum efficiency in the film state. In addition, efficient electrophosphorescence (32.8 cd A–1) employing an Ir(III) complex–poly(N-vinylcarbazole) system device is observed. Study of a series of electroluminescent, spectroscopic, and electrochemical data of the Ir(III) complex and the reference Ir(ppy)3 reveals superior performance of the new Ir(III) complex.This work was supported in parts by the Ministry of Science and Technology of Korea through a National Research Laboratory (NRL) program awarded to Prof. Soo Young Park and by Dongwoo FineChem Co., Ltd. Prof. J.-J Kim acknowledges the Ministry of Commerce, Industry and Energy of Korea through the OLED center, Center for Electro- and Photo-Responsive Molecules, and Samsung SDI Corporation for financial support

    The Modified Chimney Technique With a Thoracic Aortic Stent Graft to Preserve the Blood Flow of the Left Common Carotid Artery for Treating Descending Thoracic Aortic Aneurysm and Dissection

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    While thoracic endovascular aortic repair is an effective treatment option for descending thoracic aorta pathology, it does have limitations. The main limitation is related to the anatomical difficulties when disease involves the aortic arch. A fenestrated, branched aortic stent graft and hybrid operation has been introduced to overcome this limitation, but it is a custom-made device and is time consuming to manufacture. Furthermore, these devices cannot be used in an emergency setting. We report two patients with massive descending thoracic aortic aneurysm and ruptured aortic dissection very near the aortic arch who underwent a procedure which we named the modified chimney technique. The modified chimney technique can be used as a treatment option in such an emergency situation or as a rescue procedure when aortic pathology is involved near the supra-aortic vessels

    Sacral Intraspinal Bronchogenic Cyst: A Case Report

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    Intraspinal bronchogenic cysts are rare congenital cystic lesions. In all the reported cases, the cysts have been located in the cervical, upper thoracic or thoracolumbar segments. We report the case of an intraspinal bronchogenic cyst in the sacral location. We present the case of a 5-month-old female with a skin dimple in the midline over the sacral vertebra. Magnetic resonance image of the lumbar and sacral vertebra revealed a dermal sinus tract and an epidural cystic mass at the S2 level. The patient underwent the removal of the dermal sinus tract and the cyst. The cystic mass was shown to be connected to the subarachnoid space through a slender pedicle from the dura. The cyst was diagnosed to be a bronchogenic cyst based on the results of the histopathological examination. We conclude that intraspinal bronchogenic cysts may appear in the sacral location
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