GIC

W hen I began teaching English in Korea, standard practice was to introduce new words by writing them on the blackboard (yes, they were black), saying the new lexical item several times, then explaining its meaning and using it in a sentence. Th e teacher might follow up by asking a student or two to make their own sentence using the new lexical item before handing out a worksheet to everyone. Th e worksheet might include a matching exercise, where students were to match the words in one column with their defi nitions in the other. A second exercise might be to write each of the new words in a sentence. And with this exposure, the student was expected to "learn" the new word, which in most cases required memorization. Th e banking model of education was trending. Th e term was coined by Paulo Freire (1970) as a metaphor of students as containers to be fi lled with knowledge by the teacher, that is, to receive, fi le, and store the deposits. Th e transfer of knowledge was thought of as being unidirectional, from the teacher to the student, much like an online bank transfer is now made. Freire was the fi rst to criticize this traditional banking model, but in time, many would follow. Th e banking model is a teacher-centered approach to learning. In this conventional approach, the teacher functions as the presenter of information to students, who are expected to passively receive it. It is still quite commonly found in Korea in many university lecture halls and in even more high school classrooms, whether it is an English classroom or that of another subject. Th e relative ineffi ciencies associated with teacher-centered learning have led to the development of student-centered learning, where the focus is on the student in the learning process rather than constantly on the teacher.

In design of analog circuits not only the gain and speed are important but power dissipation, supply voltage, linearity, noise and maximum voltage swing are also important. Noise limits the minimum signal level that a circuit can process with acceptable quality. Today analog designers constantly deal with the problem of noise because it trades with power dissipation, speed, and linearity.  So in this paper a biquad GIC notch filter is design which provides low noise linearity. In this research, the design and VLSI implementation of active analog filter, based on the Generalized Impedance Converter (GIC) circuit, are presented. The analog features include the filter type (band pass, high pass, low pass or notch), the centre or cut off frequency, and the quality factor. The circuit is then modeled and simulated using the Cadence Design Tools software package. Active filters are implemented using a combination of passive and active (amplifying) components, and require an outside power source. Operational amplifiers are frequently used in active filter designs. These can have high Q factor, and can achieve resonance without the use of inductors.  This paper presents a new biquad GIC notch filter topology for image rejection in heterodyne receivers and Front End receiver applications. The circuit contains two op-amp, resistors, and capacitor topology for testing purposes. It is implemented with standard CMOS 0.18μm technology. The circuit consumes 0.54 mW of power with a open loop gain 0dB, 1 dB compression point the linear gain obtained +7.5dBm at 1.1 kHz and 105 degree phase response , from a 1.8V power supply optimum.

Third order low-pass filters are analyzed. Two different configuration of General Impedance Converter (GIC) based filters are compared to two Sallen and Key (SAK) based structures. For GIC based third-order filters realization procedures are given. The transfer functions and the component values for the third-order filters with Butterworth response are presented. The sensitivity analysis is done, and the results of Monte Carlo runs, as well as Schoeffler sensitivities are shown. The best results are obtained with the GIC based filter, which use four capacitances for the realization.

The objective of this paper is to provide a discussion of the surface impedance applicable in connection with studies of geomagnetically induced currents (GIC) in technological systems. This viewpoint means that the surface impedance is regarded as a tool to determine the horizontal (geo)electric field at the Earth’s surface, which is the key quantity for GIC. Thus the approach is different from the traditional magnetotelluric viewpoint. The definition of the surface impedance usually involves wavenumber-frequency-domain fields, so inverse Fourier transforming the expression of the electric field in terms of the surface impedance and the geomagnetic field results in convolution integrals in the time and space domains. The frequency-dependent surface impedance has a high-pass filter character whereas the corresponding transfer function between the electric field and the time derivative of the magnetic field is of a low-pass filter type. The relative change of the latter transfer func...

In this paper, the thermal decomposition of air-stable Cs-ethylene-ternary graphite intercalation compounds (GICs) is discussed. The air stability of Cs-GICs is improved remarkably after the absorption of ethylene into their interlayer nanospace, because the ethylene molecules oligomerize and block the movement of Cs atoms. In addition, the evaporation of Cs atoms from the Cs-ethylene-ternary GICs is observed above 400 • C under a N 2 atmosphere of 100 Pa by ion attachment mass spectrometry. Although the results indicate that Cs-ethylene-ternary GICs remain stable up to approximately 400 • C, their thermal stability is not very high as compared to that of Cs-GICs.

Spring is coming to Gwangju and to the Gwangju International Center (GIC). Spring always signals change-a change in the seasons but also a new beginning in human activity for the year and, of course, for the GIC. This spring has an additional change: My three-year term as chairman of the GIC Board of Directors ends and a new chairman will be beginning a new term. At this juncture, I would like to look back over the past three years of serving the community by the GIC and comment on the good work that the center has accomplished. The energy and the work ethic in the GIC office never ceases to amaze me. The office buzzes like a bee hive: The staff is always busy at their desks, attending meetings, or working on projects in and outside the office. I am sure that the work ethic exemplified by the GIC director and executive secretary have a very positive influence on the rest of the GIC staff.

Hyperbaric oxygen culture (HOC) prolongs endocrine graft survival and decreases major histocompatibility complex (MHC) class I surface expression. If graft prolongation were the result of passenger cell inactivation and decreased class I expression, then simultaneous transplantation of both a nontreated and a HOCtreated graft should result in rejection of the nontreated graft and acceptance of the HOC-treated graft. Simultaneous transplant of a nontreated and a HOC-treated thyroid allograft beneath the kidney capsule of recipient mice resulted in prolonged survival of both rafts in three Q strain combinations differing at class I (K , Dd, Db). In vitro analysis of the recipient splenic population revealed the presence of primed donor-specific cytotoxic T cells. These results suggest that recipient tolerance was not because of anergy or clonal deletion. Splenectomy at the time of transplant, revealed that both graft prolongation and the induction of recipient tolerance were dependent on the spleen. Finally, analysis of graft infiltrating cells reveals the presence of CD8' cells but no CD4' cells in tolerant recipients, whereas graft infiltrating cells from rejecting recipients contained both populations. The results suggest that active peripheral tolerance can be generated following transplantation of a HOC-treated allograft and that tolerance results from redirection of the recipients immune response. Hzlman Immunology 52, 127-l 3 7 (I 9971. 0 American Society for Histocompatibility and Immunogenetics, 1997 ABBREVIATIONS APC antigen presenting cell GIC graft infiltrating cells LDA limiting dilution analysis TcR T-cell receptor CTL HOC MHC Th cytotoxic T lymphocyte hyperbaric oxygen culture major histocompatibility complex 'I helper cell

Aims: The purpose of this study was to compare the sealing ability of Mineral Trioxide Aggregate (MTA) and Glass Ionomer
Cement (GIC) when used over gutta-percha as intracanal sealing materials. The study also evaluated the sealing ability of Zinc
oxide eugenol (ZOE) cement and Acroseal sealer.
Materials and Methods: Teeth were obturated with gutta-percha using sealer ZOE (group A, C, D) and Acroseal (group B).
The groups were further divided into 2 subgroups (15 premolars each) on the basis of intracanal sealing material used: GIC
subgroups (A1, B1) and MTA in subgroups (A2, B2). The clearing technique was used in this study for leakage evaluation.
Seventy mandibular premolars were prepared using step-back technique and divided into experimental groups A and B (30
premolars each) and the positive and negative control groups C and D (5 premolars each).
Statistical analysis used: Coronal microleakage was determined under stereomicroscope using 15X magnification. Data was
statistically analyzed using one-way ANOVA followed by Post-Hoc Multiple comparison (Bonferroni).
Results: MTA group leaked significantly less than GIC group (P < 0.05). Acroseal exhibited better sealing ability than ZOE
sealer. Teeth with no intracanal barrier showed almost complete leakage.
Conclusions: MTA may be preferred over GIC as an intracanal barrier.
Keywords: Acroseal sealer; clearing technique; GIC; intracanal barrier; intracanal sealing; MTA

January is ushering in a new year -just as it did last year. The now-naked ginkgo trees lining the city streets seem to shiver as the mercury drops below 0 degrees -this too, is the same as last year. I start my day with breakfast, before going to my computer to spend the day writing, editing, answering email, and whatnot -again, much like I did last winter. But there is one thing that is not the same as last year -not the same for me, nor for Gwangju, nor Korea, nor the world -and that is the global presence of the COVID-19 pandemic.

MiRNA-34a is considered as a potential prognostic marker for glioma, as studies suggest that its expression negatively correlates with patient survival in grade III and IV glial tumors. Here, we show that expression of miR-34a was decreased in a graded manner in glioma and glioma stem cell-lines as compared to normal brain tissues. Ectopic expression of miR-34a in glioma stem cell-lines HNGC-2 and NSG-K16 decreased the proliferative and migratory potential of these cells, induced cell cycle arrest and caused apoptosis. Notably, the miR-34a glioma cells formed significantly smaller xenografts in immuno-deficient mice as compared with control glioma stem cell-lines. Here, using a bioinformatics approach and various biological assays, we identify Rictor, as a novel target for miR-34a in glioma stem cells. Rictor, a defining component of mTORC2 complex, is involved in cell survival signaling. mTORC2 lays downstream of Akt, and thus is a direct activator of Akt. Our earlier studies have ...

Aim: To determine the effect of incorporating Casein Phosphopeptide-amorphous calciu m phosphate (CPP-ACP) into self-cured g lass-ionomer cement (GIC) and to compare the shear-peel band strength. Materials and method:1) Ion Measurements and CPP Detection: Discs of 6 mm d iam x 2 mm thick was prepared for following groups: Group I-GIC & Group II-GIC +1.56% w/ w CPP-ACP. The discs incubated at 37°C in 2mL of deionized water (pH 6.9) and 2mL of 50mM sodiu m lactate buffer at pH 5.0. The release of calciu m, inorganic phosphate, and fluoride ions was measured in each solution.2) Shear-Peel band strength: 60 Non carious human molars collected, stored in distilled water after decontamination in 0.5% ch loramine. Ext racted molars divided into 2 g roups each group containing 30 molars. Group Ibands were cemented with GIC & Group II-bands were cemented with GIC +1.56% w/w CPP-A CP. With the use of an Instron universal testing machine, a shear-peel load was applied to each cemented band. SEM analysis was done with each group. Results: Incorporation of 1.56% w/w CPP-A CP into the GIC resulted in an increase in shear peel band strength. Fluoride, Calciu m & Phosphate ions release was significantly h igher in Group II as co mpare to Group I. Conclusion: Incorporation of 1.56% w/w CPP-A CP into the GIC significantly increased shear-peel band strength and significantly enhanced the release of fluoride, calciu m and phosphate ions at neutral and acidic pH. Thus incorporation of CPP-ACP phosphate can prevent demineralization and promotes remineralization of enamel subsurface lesions.