AN INVESTIGATION INTO THE GAP BETWEEN KOREAN UNIVERSITY STUDENTS’ GRAMMATICAL AWARENESS AND PERCEPTION

Despite the consistent emphasis on grammar instruction in English classrooms in South Korea, studies regarding grammar instruction have not yet been extensively conducted. The present study aims to discover the gap between learners’ grammatical awareness and their perception of major grammatical items. A total of 60 EFL learners from two local universities in South Korea participated in the study and were divided into two groups, a high-level and a low-level group. A set of tests was utilized to examine learners’ grammatical awareness and their perception of six major grammatical items—tense, prepositions, articles, voices, morphology, and vocabulary. The results demonstrated that there was a significant difference in the scores of tense, article, and voice for grammatical awareness between the high-level and the low-level group. Also, both groups scored high for the category of voice while they received low scores for vocabulary and morphology. In addition, they showed a significant difference in the scores for the perceived difficulty of articles and voice. The high-level group perceived voice as the most difficult, whereas the low-level group perceived articles as the most difficult. These findings demonstrate a gap between the learners’ grammar awareness and perception and highlight a need to design an individualized curriculum for the effectiveness of teaching as well as self-initiated studying

Compact and cross-linked nanoparticles: nano- platform for highly stable, versatile conjugation and its bio-application

Department of Chemical EngineeringIron oxide nanoparticles (IONPs) have been investigated enormously in bio-application field including MRI contrast image, cancer cell targeting, biological sensing, and drug delivery. All these bio applicable IONPs require highly monodisperse size, biocompatibility, and long term colloidal stability in aqueous media. The synthesis of high quality IONPs was reported in the previous study. However, these uniform sizes of IONPs are constructed with hydrophobic ligand because they are synthesized in oil phase. In addition, IONPs for bio application, the surface modification step is essential. There are two main surface modification methods, ligand exchange and encapsulation with amphiphilic polymers, have been employed to produce water dispersible and biocompatible IONPs. Although encapsulation process is easy, rapid, and reproducible, there are limitations of poor purification of polymer micelle structure and increase in hydrodynamic diameter size. In this research, to overcome these limitations, ligand exchange with random copolymer which was synthesized by RAFT polymerization was used to synthesize highly compact and robust water dispersible IONPs. After 12 nm of IONPs were ligand exchanged with optimized ligand, these were maintained compact HD size about ~15??4 nm with high yield and reproducibility. Although their colloidal stability was established, functionalization of IONPs and stability in further reactions to conjugate bio molecules were required. To achieve these requirements, ???cross-linking??? using various length of diamine was investigated in this research. Cross-linking reaction proceeded by EDC coupling of diamine and carboxyl group of IONPs surface ligand. From this process, highly enhanced colloidal stability of IONPs and functionalization of amine group were expected. To confirm the cross-linked nanoparticles (CLNPs), XPS spectra and visualization with TEM analysis were performed. CLNPs enhanced stability was compared with PEG dominant ligand (IONPs-PEG) and acid included ligand (IONPs-AA) composed IONPs by broad range of pHs, NaCl solution, temperature, purification effects and ???click chemistry??? condition. These were evaluated by changes of each conditions of IONPs sizes with DLS analysis. Furthermore, as available functionalized amines of CLNPs were observed by RITC conjugation, tried to conjugate two different bio molecules. One is mannose carbohydrate conjugation was proceeded and confirmed with HR-MAS analysis and FT-IR. Also, MR relaxivity was measured by concanavalin A (Con A) mannose selective binding lectin to confirm conjugated mannose was retained their property. The other approach was folic acid conjugation. With folic acid conjugated CLNPs (CLNPs-FA), in vitro test was performed. HeLa cell which have lots of folate receptor on their surface was used to evaluate CLNPs-FA targeting ability. The result of targeting was observed with Prussian blue staining of HeLa cell. Through this research, compact and robust ligand and cross-linking conditions were optimized and confirmed various tool. At the same time, amine functionalization of IONPs were accomplished with facile method simultaneously. This ligand and cross-linking methods have great potential to be applied to the other nanoparticles for improvements of various bio applications.ope

Nanocomposite hydrogel actuators hybridized with various dimensional nanomaterials for stimuli responsiveness enhancement

Hydrogel actuators, that convert external energy, such as pH, light, heat, magnetic field, and ion strength, into mechanical motion, have been utilized in sensors, artificial muscles, and soft robotics. For a practicality of the hydrogel actuators in a wide range of fields, an establishment of robust mechanical properties and rapid response are required. Several solutions have been proposed, for example, setting porous and anisotropy structures to hydrogels with nanocomposite materials to improve the response speed and deformation efficiency. In this review paper, we focused on hydrogel actuators including various nanocomposite by categorizing the dimensional aspects of additive materials. Moreover, we described the role of diverse additive materials in terms of the improvement of mechanical property and deformation efficiency of the hydrogel actuators. We assumed that this review will provide a beneficial guidance for strategies of developing nanocomposite hydrogel actuators and outlooks for the future research directions.11Ysciescopu

Computed Tomography in Pulmonary Tuberculosis

CT scans in patients with primary tuberculosis commonly show findings of Iympho-hematogeneous spread of the disease, while those of reactivation tuberculosis commonly show findings of bronchogenic spread. Typical CT findings of primary tuberculosis are airspace consolidation of the middle and lower lobes with mediastinal and hilar lymphadenopathy showing central lower attenuation and peripheral rim en- . hancement. Typical CT findings of reactivation tuberculosis are nodular and linear pulmonary lesions at the apex without lymphadenopathy. High-resolution CT is extremely helpful in understanding the patho-morphologic changes, mode of spread of the disease, sequential morphologic change after antituberculous chemotherapy, and possibly in diagnosing activity of the disease. Centrilobular small nodule or branching linear lesions are the most common findings of fresh active pulmonary tuberculosis, which represent intra- and peri-bronchiolar caseation necrosis. CT is also useful in the evaluation of longstanding destructive pulmonary lesions and tracheobronchial tuberculosis. The importance of the role of CT scan in patients with pulmonary tuberculosis is increasing

Genomic profile of metastatic breast cancer patient-derived xenografts established using percutaneous biopsy.

BACKGROUND: Metastatic breast cancer (mBC) is a complex and life-threatening disease and although it is difficult to cure, patients can benefit from sequential anticancer treatment, including endocrine therapy, targeted therapy and cytotoxic chemotherapy. The patient-derived xenograft (PDX) model is suggested as a practical tool to predict the clinical outcome of this disease as well as to screen novel drugs. This study aimed to establish PDX models in Korean patients and analyze their genomic profiles and utility for translational research. METHODS: Percutaneous core needle biopsy or punch biopsy samples were used for xenotransplantation. Whole exome sequencing and transcriptome analysis were performed to assess the genomic and RNA expression profiles, respectively. Copy number variation and mutational burden were analyzed and compared with other metastatic breast cancer genomic results. Mutational signatures were also analyzed. The antitumor effect of an ATR inhibitor was tested in the relevant PDX model. RESULTS: Of the 151 cases studied, 40 (26%) PDX models were established. Notably, the take rate of all subtypes, including the hormone receptor-positive (HR +) subtype, exceeded 20%. The PDX model had genomic fidelity and copy number variation that represented the pattern of its donor sample. TP53, PIK3CA, ESR1, and GATA3 mutations were frequently found in our samples, with TP53 being the most frequently mutated, and the somatic mutations in these genes strengthened their frequency in the PDX model. The ESR1 mutation, CCND1 amplification, and the APOBEC signature were significant features in our HR + HER2- PDX model. Fulvestrant in combination with palbociclib showed a partial response to the relevant patient\u27s tumor harboring the ESR1 mutation, and CCND1 amplification was found in the PDX model. AZD6738, an ATR inhibitor, delayed tumor growth in a relevant PDX model. CONCLUSIONS: Our PDX model was established using core needle biopsy samples from primary and metastatic tissues. Genomic profiles of the samples reflected their original tissue characteristics and could be used for the interpretation of clinical outcomes

Effect of Combination Therapy with Sodium Ozagrel and Panax Ginseng on Transient Cerebral Ischemia Model in Rats

Sodium ozagrel (SO) prevents platelet aggregation and vasoconstriction in the cerebral ischemia. It plays an important role in the prevention of brain damage induced by cerebral ischemia/reperfusion. Recently, many animal studies have suggested that the Panax ginseng (PG) has neuroprotective effects in the ischemic brain. In this study, we assessed the neuroprotective effects that come from a combination therapy of SO and PG in rat models with middle cerebral artery occlusion (MCAO). Animals with MCAO were assigned randomly to one of the following four groups: (1) control (Con) group, (2) SO group (3 mg/kg, intravenously), (3) PG group (200 mg/kg, oral feeding), and (4) SO + PG group. The rats were subjected to a neurobehavior test including adhesive removal test and rotarod test at 1, 3, 7, 10, and 15 days after MCAO. The cerebral ischemic volume was quantified by Metamorph imaging software after 2-3-5-triphenyltetrazolium (TTC) staining. The neuronal cell survival and astrocytes expansion were assessed by immunohistofluorescence staining. In the adhesive removal test, the rats of PG or SO + PG group showed significantly better performance than those of the control group (Con: 88.1 ± 24.8, PG: 43.6 ± 11, SO + PG: 11.8 ± 7, P < .05). Notably, the combination therapy group (SO + PG) showed better performance than the SO group alone (SO: 56 ± 12, SO + PG: 11.8 ± 7, P < .05). In TTC staining for infarct volume, cerebral ischemic areas were also significantly reduced in the PG group and SO + PG group (Con: 219 ± 32, PG: 117 ± 8, SO + PG: 99 ± 11, P < .05). Immunohistofluorescence staining results showed that the group which received SO + PG group therapy had neuron cells in the normal range. They also had a low number of astrocytes and apoptotic cells compared with the control or SO group in the peri-infarction area. During astrocytes staining, compared to the SO + PG group, the PG group showed only minor differences in the number of NeuN-positive cells and quantitative analysis of infarct volume. In conclusion, these studies showed that in MCAO rat models, the combination therapy with SO and PG may provide better neuroprotective effects such as higher neuronal cell survival and inhibition of astrocytes expansion than monotherapy with SO alone

Clinical Significance of Age at the Time of Diagnosis among Young Breast Cancer Patients

PURPOSE: The aims of this study were to investigate outcomes corresponding to age at diagnosis as categorized into 5-year intervals and to explore whether endocrine-responsive tumors display clinical benefits from endocrine therapy after chemotherapy among young breast cancer patients. METHODS: A total of 1,171 patients who were under 40 years old at diagnosis between 1985 and 2007 were divided into 3 subgroups: ≤30 years (Group I, 13.3%), 31-35 years (Group II, 30.5%), and 36-40 years (Control group, 56.2%). Clinicopathological factors and outcomes were compared using a chi-square test, the Kaplan-Meier method, and Cox's hazards models. RESULTS: There were no significant differences in the characteristics and treatment patterns between the 3 groups, except for the grade, hormone receptors expression, and use of endocrine therap. Group I showed the worst survival and subsequently Group II presented worse outcomes than the Control group, mainly among hormone receptors-positive patients. Groups I and II showed increased risks of recurrence and death in multivariate analyses. Among 529 hormone receptors-positive patients who received chemotherapy, favorable outcomes for patients who were treated with endocrine agents were demonstrated, mainly in patients aged 35 years or less. However, interaction tests between the use of endocrine therapy and age at diagnosis were not significant. CONCLUSION: Age at diagnosis is an independent prognostic factor and the age of 35 years is a rational cut-off among young patients. Our subgroup analysis suggests that endocrine therapy may provide additional benefits even in young breast cancers. Therefore, further researches should be directed towards improving outcomes for this population.ope