• The Pure and Applied Mathematics
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• v.29 no.1
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• pp.59-68
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• 2022

For a finite group G ⊂ GL(n, ℂ), the G-Hilbert scheme is a fine moduli space of G-clusters, which are 0-dimensional G-invariant subschemes Z with H⁰(𝒪_Z ) isomorphic to ℂ[G]. In many cases, the G-Hilbert scheme provides a good resolution of the quotient singularity ℂⁿ/G, but in general it can be very singular. In this note, we prove that for a cyclic group A ⊂ GL(n, ℂ) of type ${\frac{1}{r}}$(1, …, 1, a) with r coprime to a, A-Hilbert Scheme is smooth and irreducible.

• Journal of the Korean Chemical Society
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• v.58 no.2
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• pp.153-159
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• 2014

Herein, the cyclic voltammetric (CV) investigations of structurally similar bisnitrocompounds (N3, N4, N5, N6, having different-$CH_2$-spacer length) is presented. CV study offered interesting interactional possibilities of bisnitrocompounds with chicken blood ds.DNA at physiological pH 4.7 and human body temperature, 310 K. The results indicated strong interaction by these symmetric molecules with ds.DNA and strength of binding is found to depend on length of $CH_2$ spacer group in their molecular structure. Thermodynamics derived from electrochemical binding parameters also favored the irreversible interactions. Moreover, threading intercalation mode of binding is suggested based on thermodynamic and kinetic binding parameters extracted from CV studies.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.243-248
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• 2004

As diverse synthetic precursors of cyclic adenosine diphosphate ribose (cADPR), several adenosine derivatives in which azido or amino group is introduced at 2'- or 3'-position of the sugar moiety of adenosine were prepared from readily available adenosine via conventional protocols. These synthetic sequence employs very efficient reactions conditions that proceed at or below ambient temperature with actual yields of >80% for each individual step.

• Steel and Composite Structures
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• v.15 no.5
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• pp.507-518
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• 2013

The seismic performance of six types of weak-axis steel moment connections was investigated through cyclic testing of six full-scale specimens. These weak-axis moment connections were the column-tree type, WUF-B type, FF-W type, WFP type, BFP-B type and DST type weak-axis connections. The testing results showed that each of these weak-axis connection types achieved excellent seismic performance, except the WFP and the WUF-B types. The WFP and WUF-B connections displayed poor seismic performance because a fracture appeared prematurely at the weld joint due to stress concentrations. The column-tree type connection showed the best seismic behavior such that the story drift ratio could reach 5%.

• Journal of the Korean Magnetic Resonance Society
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• v.17 no.1
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• pp.47-53
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• 2013

Four new cyclic peroxide compounds (1~4) were isolated from the marine sponge Plakortis simplex. Their structures including relative stereochemistry were determined by MS and NMR analysis. All compounds, a side carbon chain with 10 carbons, were very unstable. After transformation into methyl ester analogues, the structure determination was conducted. Compounds 1a and 2a are stereoisomers, assigned as $3S^*$, $4S^*$, $6R^*$ and $3R^*$, $4S^*$, $6R^*$, respectively. Similarly, compounds 3a and 4a, replaced the methoxy group with an aliphatic methyl, are also stereoisomers. Compounds 1a and 2a exhibited the strong antifungal effect against the fungus Candida albicans.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.194-199
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• 2000

The creep rate is affected by the temperature and in fact. if the temperature above $T_M/2(T_M:melting\;point)$. The aim of the present investigation is to study the relationship of static creep and cyclic creep behavior of pure copper and the formulation of these phenomena with the special attention to the instantaneous strain. strain rate from time and number of cycles have the same inclination Steady state creep rate depend upon maximum stress and can be expressed as linear function according to Power law creep equations Creep rupture time has relation with creep rate. and it make a group represented as the same direct line regardless of max stress, stress ratio and the temperature. Initial strain effect on continuous creep deformation. and have guantitative relationship between elastic and Plastic strain. LMP have similar tendency than OSDP and MHP according to temperature

• Journal of Ginseng Research
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• v.41 no.4
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• pp.556-565
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• 2017

Background: Recent studies have revealed that the properties Traditional Chinese Medicine is mostly associated with are substance and energy metabolism. Our study aimed to compare the effect of red ginseng (RG) (warm property) and ginseng leaves (GL; cold property) on the substance and energy metabolism of rats with hypothyroidism. Materials and methods: Rats were administered propylthiouracil intraperitoneally for 20 d to cause hypothyroidism. The reference group was orally administered Aconiti Lateralis Radix Praeparaia [FZ (Fuzi in Chinese)], while both the RG and GL groups were orally administrated crude drugs. The rectal, tail, toe, and axilla temperature of the rats were assayed every 3 d. Oxygen consumption, carbon dioxide production, heat production, and energy expenditure were measured via TSE phenoMaster/LabMaster animal monitoring system. Adenosine monophosphate-activated protein kinase, $Na^+-K^+$-ATPase, fumarase, pyruvic acid and cyclic adenosine monophosphate/cyclic guanosine monophosphate were determined. Results: The lower levels of triiodothyronine, tetraiodothyronine, and thyrotropin-releasing hormone and the higher level of thyroid stimulating hormone revealed the successful establishment of a hypothyroidism model. Oxygen consumption, carbon dioxide production, heat production, and energy expenditure in the FZ and RG groups were obviously increased. The activity of $Na^+-K^+$-ATPase and fumarase in the FZ and RG groups was significantly increased. The cyclic adenosine monophosphate/cyclic guanosine monophosphate level in the FZ and RG groups was increased, while the GL group showed the opposite. Conclusion: Our research provides a new way to explore the efficiency of Chinese medicine on the basis of the relationship between drug property and effects on substance and energy metabolism.

• The Journal of Advanced Prosthodontics
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• v.8 no.1
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• pp.62-69
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• 2016

PURPOSE. The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS. Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS. The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION. Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.54-65
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• 2008

The purpose of this study was to determine the effect of sodium hypochlorite and steam autoclaving on the cyclic fatigue of nickel-titanium endodontic files. Two types of files with a .06 taper and #30 were used, $K3^{(R)}$ (SybronEndo, Glendora, California, USA) and Hero $642^{(R)}$(Micro-Mega, BesanCon, France). The files were divided into 6 experimental groups containing 10 files each group depending the soaking time in 6% sodium hypochlorite solution and number of cycles of steam autoclave. After sterilization, a cyclic fatigue test was performed on each file, and the fracture time was recorded in seconds. The control group underwent the cyclic fatigue test only. After the test, the surface characteristics of the files were observed using scanning electron microscopy (SEM). All groups containing the Hero 64~ files showed a similar cyclic fatigue fracture time. However, the cyclic fatigue fracture time with the $K3^{(R)}$ files was significantly shorter in groups which were treated with sodium hypochlorite than in the control group (P < 0.05), SEM revealed both Hero $642^{(R)}$ and $K3^{(R)}$ files to have significant corrosion on the file surface in groups treated with sodium hypochlorite, compared with the sharp and regular blades of the control group. $K3^{(R)}$ files showed more corrosion than the Hero $642^{(R)}$ files. Bluntness of the blades of the $K3^{(R)}$ file was observed in groups treated with steam autoclave. Although there was no obvious destruction on the surface of steam autoclaved Hero $642^{(R)}$ files, slight bluntness was observed. Sterilizing with a steam autoclave is much less destructive to $K3^{(R)}$ files than sodium hypochlorite. The longer time exposed to sodium hypochlorite, the more destructive pattern was shown on the blades of the files. Therefore, when using sodium hypochlorite solution, the exposure time should be as short as possible in order to prevent corrosion and increase the cyclic fatigue fracture time.

• Journal of the Chungcheong Mathematical Society
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• v.18 no.1
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• pp.23-31
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• 2005

In this paper, we observe the relation between the concept of generalized Gottlieb groups and the Hurewicz homomorphism.