Microscopic Features of Fractured Fragment of Nickel-Titanium Endodontic Instruments by Two Different Modes of Torsional Loading

This study compared the microscopic features of the fractured endodontic nickel-titanium (NiTi) rotary instruments by two different torsional loadings: repetitive torsional loading (RTL) and single torsional loading (STL) based on the International Organization for Standardization (ISO). ProTaper Next, HyFlex EDM, and V-Taper 2 were compared in this study. In the STL method, the torsional load was applied after fixing the 3 mm tip of the file, by continuous clockwise rotation (2 rpm) until fracture. In the RTL method, a preset rotational loading (0.5 N·cm) was applied and the clockwise loading to the preset torque and counterclockwise unloading to original position were repeated at 50 rpm until the file fractured. Fractured fragments by two methods were compared under a scanning electron microscope (SEM) to examine the topographic features of the fractured surfaces and longitudinal aspects. SEM examinations showed significantly different features according to the loading methods. Specimens from the RTL method showed ruptured aspects on cross sections, with multiple areas of initiated cracks while the STL method showed the typical features of torsional failure, such as circular abrasion marks and fatigue dimples. This study suggested a new repetitive torsional loading method which is much more clinically relevant and may result in a different fracture feature from STL method

Analysis of triterpenoids, carotenoids, and phenylpropanoids in the flowers, leaves, roots, and stems of white bitter melon (Cucurbitaceae, Momordica charantia)

Purpose: To evaluate the contents of carotenoids, triterpenoids, and phenylpropanoids in different parts of white bitter melon.Methods: We evaluated the accumulation of 2 triterpenoids, 10 carotenoids, and 11 phenylpropanoids in different parts of white bitter melon, including fruits at four different developmental stages using HPLC.Results: Charantin, lutein, and rutin were the main triterpenoids, carotenoids, and phenylpropanoids, respectively. The accumulation of triterpenoids (momordicine and charantin), carotenoids (antheraxanthin, lutein, violaxanthin, α-carotene, and β-carotene), and phenylpropanoids (caffeic acid, chlorogenic acid, epicatechin, gallic acid, p-coumaric acid, rutin, and trans-cinnamic acid) was high inthe leaves and/or flowers, which are exposed to direct sunlight, but low in the roots.Conclusion: Most of the analyzed components were accumulated at high levels in the leaves and/or flowers. These results will help exploit the compounds in various parts of white bitter melon that are beneficial for human health. Keywords: Momordica charantia, Bitter melon, Triterpenoid, Carotenoid, Phenylpropanoi

Influence of pectin on phenylpropanoid accumulation in buckwheat (Fagopyrum esculentum) sprout

Buckwheat (Fagopyrum esculentum Monech) contains several secondary metabolites like phenolic chemicals. Pectin has been demonstrated to be an efficient elicitor from the biotic group for triggering the defensive response, which enhances the production of secondary metabolites. In this study, the effect of pectin on the growth of buckwheat sprouts and the production of phenylpropanoid compounds in common buckwheat sprouts was investigated by using high-performance liquid chromatography (HPLC). Pectin treatments of 0, 2, 4, 6, and 8 mg/L were administered on buckwheat sprouts for ten days to assess the growth characteristics and optimum concentrations. In comparison to the control treatment, 2 mg/L pectin enhances the shoot length by 24%. But when pectin concentration continued to rise, a tendency toward shorter shoots was seen. Pectin treatment decreased the fresh weight of the sprout as compared to the control treatment. The phenylpropanoid accumulation in buckwheat sprouts varied depending on the amount of pectin utilized. Pectin treatment at 6 mg/L resulted in a 15.10% increase in total phenylpropanoid accumulation. The findings of this study indicate that pectin is a possible elicitor, however, more research on how pectin affects the buildup of phenylpropanoids in buckwheat sprouts would be more intriguing to examine the implications of this work

Clinical Experiences of Cardiac Myxoma

Although cardiac myxoma is rare, it is the most common primary cardiac tumor. Seventy-four cases of cardiac myxoma that were surgically treated in our center between August 1980 and February 2005 were retrospectively reviewed. The mean patient age was 50.4 ± 15.0 (range 7-80) years, and 53 patients (71.6%) were female. The most common preoperative symptom, occurring in 44 patients, was dyspnea. The interval from onset of symptoms to surgery was 9 months. Seventy cases were located in the left atrium, 3 in the right atrium and 1 in the right ventricle. The myxoma in the right ventricle could not be resected completely, due to severe infiltration. Cardiopulmonary bypass and aortic cross clamp times were 100.4 ± 37.1 and 64.8 ± 29.8 minutes, respectively. There were no hospital deaths, and 7 patients suffered from postoperative complications including atrial fibrillation in 2 cases. During the follow up period (mean 105.7 ± 73.6 months), there was no tumor recurrence and 6 late deaths that were not related to the underlying tumor. There was no evidence of tumor growth in the cases with incomplete resection during the 14-month follow-up. In conclusion, in this study there was no recurrence of tumors after complete resection and surgical resection is considered to be the curative method of treatment for cardiac myxoma

A Novel Application of Amniotic Membrane in Patients with Bullous Keratopathy

To evaluate the efficacy of amniotic membrane in the management of painful bullous keratopathy secondary to the intractable glaucoma and in preventing exposure of drainage devices, we inserted Ahmed valve with amniotic membrane patch graft over the implant itself, and debrided corneal epithelium with amniotic membrane graft over the exposed stroma as a single operation. During the follow-up periods, we monitored vision, intraocular pressure (IOP), presence of ocular pain, and postoperative complications associated with the implants. The mean follow up period was 8.4±3.2 months. IOP was well controlled after the intervention. The preoperative mean IOP was measured as 43.9±9.0 mmHg and lowered to 16.1±1.8 mmHg at the last visit and no complications associated with the implants were noted. Even though the improvement in vision was not prominent, the ocular surface stabilized rapidly and ocular pain associated with bullous keratopathy disappeared soon after surgery. Conclusively the use of amniotic membrane in conjunction with Ahmed valve implantation is an effective way to relieve ocular pain and lessen the chances of complications associated with the implant in patients with intractable glaucoma and bullous keratopathy

Electrically tunable slow light using graphene metamaterials

Metamaterials with classical analogues of electromagnetically induced transparency open new avenues in photonics for realizing smaller, more efficient slow light devices without quantum approaches. However, most of the metamaterial-based slow light devices are passive, which limits their practical applications. Here, by combining diatomic metamaterials with a gated single-layer graphene, we demonstrate that the group delay of terahertz light can be dynamically controlled under a small gate voltage. Using a two coupled harmonic oscillators model, we show that this active control of group delay is made possible by an effective control of the dissipative loss of the radiative dark resonator by varying the graphene’s optical conductivity. Our work may provide opportunities in the design of various applications such as compact slow light devices and ultrasensitive sensors and switches

Suppressive Effect on Lipopolysaccharide-Induced Proinflammatory Mediators by Citrus aurantium L. in Macrophage RAW 264.7 Cells via NF-κB Signal Pathway

Citrus fruits have been used as an edible fruit and a traditional medicine since ancient times. In particular, the peels of immature citrus fruits are used widely in traditional herbal medicine in Korea, as they are believed to contain bioactive components exerting anti-inflammatory activity. This study examined whether the crude methanol extract of Citrus aurantium L. (CME) has a suppressive effect on inducible enzymes and proinflammatory cytokines by inhibiting the NF-κB pathway in LPS-stimulated macrophage RAW 264.7 cells. The cells were pretreated with the indicated concentrations of CME (5, 10, 20, and 50 μg/mL) and then treated with LPS (1 μg/mL). The results showed that CME (10, 20, and 50 μg/mL) inhibited the LPS- (1 μg/mL) induced mRNA and protein expression of iNOS in macrophage Raw 264.7 cells. In addition, the expression of COX-2 was inhibited at the mRNA and protein levels by CME in a dose-dependent manner. The mRNA expression of proinflammatory cytokines, such as TNF-α and IL-6, were markedly reduced by CME (10, 20, and 50 μg/mL). Moreover, CME clearly suppressed the nuclear translocation of the NF-κB p65 subunits, which was correlated with its inhibitory effect on I-κB phosphorylation. These results suggest that CME has anti-inflammatory properties by modulating the expression of COX-2, iNOS, and proinflammatory cytokines, such as TNF-α and IL-6, in macrophage RAW 264.7 cells via the NF-κB pathway