Tuning the electronic band structure of PCBM by electron irradiation

Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that the lowest unoccupied molecular orbital (LUMO) level of PCBM up-shifts toward the vacuum energy level, while the highest occupied molecular orbital (HOMO) level down-shifts when PCBM is electron-irradiated. The shift of the HOMO and the LUMO levels increases as the irradiated electron fluence increases. Accordingly, the band-edge position and the bandgap of PCBM can be controlled by adjusting the electron fluence. Characterization of electron-irradiated PCBM reveals that the variation of the band structure is attributed to the molecular structural change of PCBM by electron irradiation

Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti

We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices

Improvement in the photoelectrochemical responses of PCBM/TiO2 electrode by electron irradiation

The photoelectrochemical (PEC) responses of electron-irradiated [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/TiO2 electrodes were evaluated in a PEC cell. By coating PCBM on TiO2 nanoparticle film, the light absorption of PCBM/TiO2 electrode has expanded to the visible light region and improved the PEC responses compared to bare TiO2 electrode. The PEC responses were further improved by irradiating an electron beam on PCBM/TiO2 electrodes. Compared to non-irradiated PCBM/TiO2 electrodes, electron irradiation increased the photocurrent density and the open-circuit potential of PEC cells by approximately 90% and approximately 36%, respectively at an optimum electron irradiation condition. The PEC responses are carefully evaluated correlating with the optical and electronic properties of electron-irradiated PCBM/TiO2 electrodes

Accuracy and Efficacy of Ultrasound-Guided Pes Anserinus Bursa Injection

The term “pes anserinus tendinobursitis (PATB)” is generally used to describe the inflammatory condition of pes anserinus bursa (PAB). Ultrasound (US) is widely used as a diagnostic and therapeutic tool to improve the assessment and management of joints and soft tissues. We performed the study to prove the accuracy and efficacy of US-guided injections in patients with PATB by comparing blind interventions. Forty-seven patients were randomly assigned to an US-guided and a blind injection group. The patients in the US-guided group were given injections under sonographic visualization. Otherwise, in the blind group, injections were provided in the conventional technique without any sonographic guidance. After the management, the accuracy of the injections was assessed by identifying the injectate location using the US. Treatment efficacy was evaluated using the visual analog scale (VAS) of knee tenderness. The US-guided group showed that the injectates were located at the PAB accurately in all participants, whereas the blind group revealed that the materials were found to be at the bursa side only in 4 out of 22 patients. VAS scores of the US-guided group significantly improved compared to the blind group. In conclusion, US-guided PAB injections are more accurate and efficacious than blind approaches

A New On-The-Move Integer Ambiguity Determination Method for Precise Positioning of Highly Maneuvering Ground Vehicles

In the conventional RTK (Real Time Kinematics), carrier phase measurements should be collected for several minutes in stationary state in order to determine the IA (Integer Ambiguity) in carrier phase to get the precise position. To determine the IA in motion, several OTM-RTK (On-The-Move RTK) methods have been proposed using vehicle dynamics or augmenting additional sensors. This paper presents a new OTM-RTK technique to determine the IA without aids of external sensors for precise positioning of highly maneuvering ground vehicles. In the proposed technique, the initial IA is determined fast by estimating precise position change during epochs using dual frequency carrier phase measurements. Therefore, IA determination of the proposed method is not influence by vehicle dynamics. By field experiment, performance of the proposed technique is analyzed including IA determination time according to vehicle dynamics and the number of visible SV

Cordycepin promotes apoptosis by modulating the ERK-JNK signaling pathway via DUSP5 in renal cancer cells

Constitutive activation of extracellular signal regulated kinase (ERK)-Jun NH2-terminal kinase (JNK) signaling commonly occurs in tumors. The activation of ERK promotes cell proliferation, whereas that of JNK induces cell apoptosis. However, the apoptotic mechanism of ERK-JNK signaling in cancer is not well understood. Recently, we identified that apoptosis and activation of the JNK signaling pathway were induced after cordycepin treatment in human renal cancer, suggesting that JNK signaling might contribute to TK-10 cell apoptosis. We investigated the apoptotic effects of cordycepin by evaluating the activation of the ERK-JNK signaling pathway in renal cancer TK-10 cells. We found that cordycepin downregulated ERK and DUSP5, upregulated phosphorylated-JNK (p-JNK), and induced apoptosis. Moreover, we showed that siRNA-mediated inhibition of ERK downregulated DUSP5, whereas ERK overexpression upregulated DUSP5, and that DUSP5 knockdown by siRNA upregulated p-JNK. The JNK-specific inhibitor SP600125 upregulated nuclear translocation of β-catenin, and downregulated Dickkopf-1 (Dkk1), which has been shown to be a potent inhibitor of Wnt signaling. Dkk1 knockdown by siRNA upregulated nuclear β-catenin, suggesting the involvement of the Wnt/β-catenin signaling pathway. DUSP5 overexpression in TK-10 cells decreased p-JNK and increased nuclear β-catenin. The decreased Bax activation markedly protected against cordycepin-induced apoptosis. Bax subfamily proteins induced apoptosis through caspase-3. Taken together, we show that JNK signaling activation by cordycepin mediated ERK inhibition, which might have induced Bax translocation and caspase-3 activation via regulation of DUSP5 in TK-10 cells, thereby promoting the apoptosis of TK-10 cells. Targeting ERK-JNK signaling via the apoptotic effects of cordycepin could be a potential therapeutic strategy to treat renal cancer