Hesperidin Shows Protective Effects on Renal Function in Ischemia-induced Acute Kidney Injury (Sprague-Dawley Rats).

OBJECTIVE: Hesperidin is a well-known flavanone glycoside copiously found in sweet orange and lemon, which was recently reported to possess significant anti-inflammatory, analgesic, antifungal, antiviral, antioxidant, and anticancer activities. Ischemia-reperfusion (I/R) injury is a major problem after renal transplantation. Furthermore, inflammatory responses to I/R exacerbate the resultant renal injury. In the present study, we investigated whether hesperidin exhibits renoprotective effects against I/R-induced acute kidney injury in a rat model. METHODS: We fed Sprague-Dawley rats either hesperidin (100 mg/kg/d) or saline. One week later, ischemia was induced by bilateral renal pedicle occlusion for 30 minutes followed by reperfusion. The rats were randomly divided into 3 groups, which were treated as follows: 1. the sham operated group; 2. the I/R group; 3. the I/R-hesperidin group RESULTS: Compared to the sham group, the I/R group had higher expression of blood urea nitrogen and serum creatinine and lower expression of catalase, superoxide dismutase, glutathione peroxidase, antioxidants, and nitric oxide. Compared to the I/R group, the I/R-hesperidin group had higher expression of catalase, superoxide dismutase, glutathione peroxidase, antioxidant, and nitric oxide and lower expression of blood urea nitrogen and serum creatinine. CONCLUSIONS: Hesperidin improved acute renal I/R injury through its antioxidant effects. These findings suggest that hesperidin is a potential therapeutic agent for acute ischemia-induced renal damage.

Investigation of SF6 injection during cyclic C2H2/SF6 flow for the formation of geometrically controlled carbon coils.

Carbon coils could be synthesized using C2H2/H2 as source gases along with SF6 as an incorporated additive gas using a thermal chemical vapor deposition (CVD) system. To obtain geometrically controlled carbon coils, a cyclic process, namely the turning on and off of C2H2 or SF6 flow during the initial reaction stage, was carried out. According to the different reaction processes, different interruption/injection times of C2H2 or SF6 flow and different injection sequences of the gas flow were investigated while maintaining the identical overall injection time of C2H2 and/or SF6 flow. The formation of carbon microcoils (CMCs) is favored by the lowest interruption/injection time ratio of SF6 flow within one cycle. In addition, the injection of SF6 flow prior to the injection of C2H2 flow promotes the formation of CMCs. Based on these results we revealed the role of the SF6 flow injection for the enhanced formation of geometrically controlled CMCs. The etching of materials, thereby promoting an increase in the number of nucleation sites for the survived growth species to form CMCs, by the increased fluorine concentration, originating from the dominant SF6 influx, is understood to be the main cause for the exclusive CMCs formation.

Developing aspect of carbon coils formation during the beginning stage of the process.

Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition system. The surface morphologies of samples were investigated step by step during the beginning stage of the process. After finishing the substrate temperature set to 750 degrees C, the formation of circular-type nickel clusters were observed in places. By setting the total pressure to 100 Torr, most of the circular-type clusters were disappeared, whereas a few number of big-sized circular-type clusters having several micrometer-sized diameters were infrequently observed. After 0.5 minutes deposition reaction, carbon nanofilaments could be observed on a specific point of the sample. Further deposition reaction gave rise to the increase in the density of carbon nanofilaments as a form of two similar shaped carbon nanofilaments sticked together. After 10 minutes deposition reaction, the nanosized wave-like carbon coils was formed first and then the formation of the microsized carbon coils would be initiated from the nanosized wave-like carbon coils.

Dominant formation of the microsized carbon coils by a short time SF6 flow incorporation during the initial deposition stage.

By SF6 gas incorporation for relatively short time during the initial deposition stage, carbon coils could be formed on nickel catalyst layer-deposited silicon oxide substrate using C2H2 and H2 as source gases under thermal chemical vapor deposition system. The characteristics (formation density and morphology) of as-grown carbon coils were investigated as a function of SF6 flow injection time. 5-min SF6 flow injection time is appropriate to produce the dominant microsized geometry for carbon coils without the appearance of the nanosized carbon coils. The geometry for the microsized carbon coils follows a typical double-helix structure and the shape of the rings constituting the coils is a flat-type. Fluorine's intrinsic etching characteristics for the nanosized carbon coils during the initial deposition stage seems to be the cause for the dominant formation of the microsized carbon coils in the case of 5-min SF6 flow injection time.

Formation of the geometrically controlled carbon coils by manipulating the additive gas (SF6) flow rate.

Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under the thermal chemical vapor deposition system. The nickel catalyst layer deposition and then hydrogen plasma pretreatment were performed prior to the carbon coils deposition reaction. The flow rate and the injection time of SF6 varied according to the different reaction processes. Geometries of carbon coils developed from embryos to nanosized coils with increasing SF, flow rate from 5 to 35 sccm under the short SF6 flow injection time (5 minutes) condition. The gradual development of carbon coils geometries from nanosized to microsized types could be observed with increasing SF6 flow rate under the full time (90 minutes) SF6 flow injection condition. The flow rate of SF6 for the coil-type geometry formation should be more than or at least equal to the flow rate of carbon source gas (C2H2). A longer injection time of SF6 flow would increase the size of coils diameters from nanometer to micrometer.

Effect of gas phase composition cycling on/off modulation numbers of C2H2/SF6 flows on the formation of geometrically controlled carbon coils.

Carbon coils can be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under a thermal chemical vapor deposition system. In this study, nickel catalyst layer deposition and then hydrogen plasma pretreatment were performed prior to the carbon coils deposition reaction. To obtain geometrically controlled carbon coils, source gases and SF6 were manipulated as the cycling on/off modulation numbers of C2H2/SF6 flows. The cycling numbers were varied according to the different reaction processes. The increased cycling numbers could develop the wave-like nano-sized carbon coils. By further increasing the cycling numbers, however, the nanostructured carbon coils seemed to deteriorate. As a result, the maximum formation of geometrically controlled carbon coils was achieved by adjusting the cycling numbers. The enhanced etching capability of the fluorine-related species in SF6 additive gas was considered for the main objective of controlling the geometry of carbon coils.