• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.76-88
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• 1995

The purpose of this was to evaluate the in vitro effects of different application modes of tetracycline HCI on dentin root surfaces. The study group was comprised of 30 teeth with advanced periodontal disease extracted before the start of periodontal therapy. The diseased root surface was vigorously root planed to expose dentin. The teeth were sectioned and cotton pellets. soaked in a saturated solution of tetracycline HCI, were either "placed" or "burnished" on the prepared root surface for 3, 5 min. respectively. Control surfaces were similarly treated with root planing only. Following the various treatments, teeth were fixed. dehydrated, critical point dried, and coated for scanning electron microscopic(SEM) evaluation. The surfaces of tetracycline HCI treated specimens considerably differed from specimens treated with root planing only. Results demonstrated that root-planed, no-tetracycline HCI specimens had amorphous, irregular surface which corresponded to a smear layer. Tetracycline HCI specimens exhibited collagen fibers and dentinal tubules exposed by the removal of the smear layer. Although some differences were seen in surface structures among some specimens. "burnished" application causes more extensive change than "placed" application, and application time of the tetracycline HCl did not seem to have any major impact on the surface morphology.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.635-644
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• 2023

Due to the rapid development of the livestock industry, particularly due to residual pharmaceutical antibiotics, environmental populations have been negatively affected. Herein, we report a ZnO/melamine-functionalized carboxylic-rich graphene oxide (ZFG) photocatalyst for visible light-driven photocatalytic degradation of tetracycline hydrochloride in aqueous solutions. The properties of the photocatalysts were evaluated by XRD, FTIR, XPS, Fe-SEM, HR-TEM, TGA, Raman spectroscopy, UV-Vis spectroscopy, zeta potential, and electrochemical measurements. The photocatalytic activity was measured using high-performance liquid chromatography. The photocatalytic properties of the ZFG photocatalyst evaluated against the tetracycline hydrochloride (TCH) antibiotic under visible light irradiation showed superior photodegradation of 96.27% within 60 min at an initial pH of 11. The enhancement of photocatalytic degradation was due to the introduction of functionalized graphene, which increases the light-harvesting capability and molecular adsorption capability in addition to minimizing the recombination rate of photogenerated charge carriers due to its role as an electron acceptor and mediator.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.370-375
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• 2005

The objective of this study was to develop a new reverse micelle-based microencapsulation technique to load tetracycline hydrochloride into PLGA microspheres. To do so, a reverse micellar system was formulated to dissolve tetracycline hydrochloride and water in ethyl formate with the aid of cetyltrimethylammonium bromide. The resultant micellar solution was used to dissolve 0.3 to 0.75 g of PLGA, and microspheres were prepared following a modified solvent quenching technique. As a control experiment, the drug was encapsulated into PLGA microspheres via a conventional methylene chloride-based emulsion procedure. The micro­spheres were then characterized with regard to drug loading efficiency, their size distribution and morphology. The reverse micellar procedure led to the formation of free-flowing, spherical microspheres with the size mode of 88 ~m. When PLGA microspheres were prepared follow­ing the conventional methylene chloride-based procedure, most of tetracycline hydrochloride leached to the aqueous external phase: A maximal loading efficiency observed our experimental conditions was below $5\%$. Their surfaces had numerous pores, while their internal architecture was honey-combed. In sharp contrast, the new reverse micellar encapsulation technique permitted the attainment of a maximal loading efficiency of 63.19 $\pm$$0.64\%$. Also, the microspheres had smooth and pore-free surfaces, and hollow cavities were absent from their internal matrices. The results of this study demonstrated that PLGA microspheres could be successfully prepared following the new reverse micellar encapsulation technique.

• Nanomaterials
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• v.12 no.17
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• pp.2945-2957
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• 2022

In this work, the growth of extended tri-s-triazine units (melem units) on g-C₃N₄ (CN) by hydrothermal treatment and its effect on the photodegradation efficiency of tetracycline hydrochloride (TC) is investigated. The CN-180-x and CN-200-6 samples were prepared using different hydrolysis times and temperatures, and they were characterized by multiple physicochemical techniques. In addition, their photodegradation performance was evaluated under visible light irradiation. Compared to the CN, CN-180-6 possesses remarkable photocatalytic degradation efficiency at 97.17% towards TC removal in an aqueous solution. The high visible-light-induced photo-reactivity of CN-180-6 directly correlates to charge transfer efficiency, numerous structural defects with a high specific surface area (75.0 m² g^-1), and sufficient O-functional groups over g-C₃N₄. However, hydrothermal treatment at a higher temperature or during a longer time additionally induces the growth of extended melem units on the surface of g-C₃N₄, resulting in the inhibition of the charge transfer. In addition, the superoxide radical is proven to be generated from photoexcited reaction and plays a key role in the TC degradation.

• Journal of Ginseng Research
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• v.24 no.2
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• pp.94-98
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• 2000

Tetracycline hydrochloride (TC) caused 100%, 50% and 20% mortality rates among rats injected with 40 mg, 30 mg and 20 mg/100g. b.w. respectively; while the morta]ity rates were decreased to 50%, 20% and 10% when Panax ginseng (2 mg/100g. b.w.) injected with TC during 72 hrs. post-injection. Subacute-toxicity study demonstrated that TC caused severe hepato-nephrotoxicity (demonstrated by biochemical analysis of serum including: transferases , alkaline phosphatase, total protein, glucose, cholesterol urea and creatinine) in rats injected i.p. with 10 mg and 5 mg/100g. b.w. for 7 days of daily injection . These signes of toxicity were greatly diminished by P. ginseng addition to TC doses.

• Journal of Periodontal and Implant Science
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• v.19 no.2
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• pp.139.1-139.1
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• 1989

• 대한치주과학회:학술대회논문집
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• 2004.11a
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• pp.103-103
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• 2004

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.333-336
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• 2005

The objective of this study was to investigate the stability of tetracycline HCl on encapsulation into and inside reverse micelles. To do so, tetracycline HCl was first mixed with cetyltrimethylammonium bromide, water and ethyl formate to make reverse micelles. The degradation kinetics of tetracycline HCl inside the reverse micelles was then assessed by scrutinizing its stability data. Under our experimental conditions, the reverse micelles formed spontaneously in absence of any mixing devices. During the preparation of the reverse micelles, however, considerable portions of tetracycline HCl underwent a chemical reaction (e.g., epimerization). For instance, $51.4{\pm}0.6%$ of an initial concentration of tetracycline HCl was transformed into a degradation product. Once dissolved inside the reverse micelles, the degradation of tetracycline HCl followed an exponential decay pattern. The plot of log{the degradation rate of tetracycline HCl} versus log{tetracycline HCl concentration} made it possible to determine the order of degradation reaction and rate constant. It was proven that the degradation of tetracycline HCl inside the reverse micelles followed a first order kinetics with a rate constant of 0.0027 $hour^{-1}$. Meriting further investigation might be formulation studies to stabilize tetracycline HCl on encapsulation into and inside the reverse micelles.

• 대한치주과학회:학술대회논문집
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• 1994.12a
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• pp.54-54
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• 1994

• Korean Journal of Materials Research
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• v.31 no.6
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• pp.325-330
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• 2021

Bi₂MoO₆ (BMO) via the structure-directing role of CO(NH₂)₂ is successfully prepared via a facile solvothermal route. The structure, morphology, and photocatalytic performance of the nanoflake BMO are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence spectrum analysis (PL), UV-vis spectroscopy (UV-vis) and electrochemical test. SEM images show that the size of nanoflake BMO is about 50 ~ 200 nm. PL and electrochemical analysis show that the nanoflake BMO has a lower recombination rate of photogenerated carriers than particle BMO. The photocatalytic degradation of tetracycline hydrochloride (TC) by nanoflake BMO under visible light is investigated. The results show that the nanoflake BMO-3 has the highest degradation efficiency under visible light, and the degradation efficiency reached 75 % within 120 min, attributed to the unique hierarchical structure, efficient carrier separation and sufficient free radicals to generate active center synergies. The photocatalytic reaction mechanism of TC degradation on the nanoflake BMO is proposed.