Conductance of a single molecule anchored by an isocyanide substituent to gold electrodes

The effect of anchoring group on the electrical conductance of a single molecule bridging two Au electrodes was studied using di-substituted (isocyanide (CN-), thiol (S-) or cyanide (NC-)) benzene. The conductance of a single Au/1,4-diisocyanobenzene/Au junction anchored by isocyanide via a C atom (junction with the Au-CN bond) was $3 \times 10 ^{-3} G_{0}$ ($2e^{2}/h$). The value was comparable to $4 \times 10 ^{-3} G_{0}$ of a single Au/1,4-benzenedithiol/Au junction with the Au-S bond. The Au/1,4-dicyanobenzene/Au molecular junction with the Au-NC bond did not show well-defined conductance values. The metal-molecule bond strength was estimated by the distance over which the molecular junction was stretched before breakdown. The stretched length of the molecular junction with the Au-CN bond was comparable to that of the Au junction, indicating that the Au-CN bond was stronger than the Au-Au bond.Comment: 3 figures, to be appear in Appl. Phys. Let

Camptothecin induces urokinase-type plasminogen activator gene-expression in human RC-K8 malignant lymphoma and H69 small cell lung cancer cells.

We previously reported that anthracyclines, which could generate reactive oxygen species (ROS), could induce the urokinase-type plasminogen activator (uPA) gene expression in human RC-K8 malignant lymphoma cells and in H69 small cell lung cancer (SCLC) cells. In screening other uPA-inducible anti-cancer agents, we found that camptothecin (CPT) and its derivative, SN38, could induce uPA in RC-K8 and H69 cells. CPT and SN38, which are also used for the treatment of lymphoma and SCLC, significantly increased the uPA accumulation in the conditioned media of both cells in a dose-dependent manner. The maximum induction of uPA mRNA levels was observed 24 h after stimulation. Pretreatment with pyrrolidine dithiocarbamate (PDTC), an anti-oxidant, inhibited the CPT-induced uPA mRNA expression. Thus, CPT induces uPA through gene expression, and, therefore, CPT may influence the tumor-cell biology by up-regulating the uPA/plasmin system.</p

Application of the powder of porous titanium carbide ceramics to a reusable adsorbent for environmental pollutants

The aim of this study is to investigate the utilization of the powder of porous titanium carbide (TiC) ceramics as a novel adsorbent or a material for solid-phase extraction (SPE). The adsorption and elution of inorganic and organic pollutants, Pb(II), 2,4,6-trichlorophenol (TCP), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), to the material were evaluated. The cartridge packed with TiC ceramics powder was used for the extraction test of pollutants. The solution containing pollutants at 1.0 mu g mL(-1) was passed through the TiC cartridge, and the substances were almost quantitatively removed. Furthermore, the pollutants retained in the cartridge were eluted with 3 N HCl for Pb(II) and with methanol for organic pollutants. The recoveries of pollutants were over 80%. In addition, we used the TiC cartridge for the solid-phase extraction of water samples (500 mL each of the distilled water and the river water) by adding pollutants at determined concentrations. Every pollutant was adsorbed almost quantitatively, and eluted by 3 N HCl or methanol. From these results, we concluded that the powder of porous TiC ceramics is a useful reusable adsorbent for the water cleanup and solid-phase extraction.ArticleJOURNAL OF HAZARDOUS MATERIALS. 185(2-3):725-731 (2011)journal articl

Risk factors for perioperative venous thromboembolism: A retrospective study in Japanese women with gynecologic diseases

BACKGROUND: Patients with gynecologic cancer have a high risk of venous thromboembolism (VTE) like patients with other cancers. However, there is little information on risk factors for VTE during gynecologic surgery and no uniform preventive strategy. Our objectives were to identify risk factors for perioperative VTE in gynecologic patients and establish methods for prevention. METHODS: We analyzed 1,232 patients who underwent surgery at the Department of Obstetrics and Gynecology of St. Marianna University School of Medicine between January 2005 and June 2008. We investigated (1) risk factors for preoperative VTE, (2) use of an inferior vena cava (IVC) filter, and (3) risk factors for postoperative VTE. RESULTS: There were 39 confirmed cases of perioperative VTE (3.17%), including 25 patients with preoperative VTE and 14 with postoperative VTE. Thirty-two patients had cancer and seven patients had benign diseases. Twenty-two of the 32 cancer patients (68.7%) had preoperative VTE, while postoperative VTE occurred in 10 cancer patients. Multivariate analysis indicated that ovarian cancer, tumor diameter ≥10 cm, and previous of VTE were independent risk factors for preoperative VTE. Among ovarian cancer patients, multivariate analysis showed that an age ≥50 years, the presence of heart disease, clear cell adenocarcinoma, and tumor diameter ≥20 cm were independent risk factors for preoperative VTE. The factors significantly related to preoperative VTE in patients with benign disease included previous VTE, age ≥55 years, tumor diameter ≥20 cm, and a history of allergic-immunologic disease. Thirteen of the 25 patients (52%) with preoperative VTE had an IVC filter inserted preoperatively. Postoperative screening (interview and D-dimer measurement) revealed VTE in 14/1,232 patients (1.14%). Multivariate analysis indicated that cancer surgery, a history of allergic-immunologic disease, and blood transfusion ≥2,000 ml were independent risk factors for postoperative VTE. CONCLUSIONS: Perioperative VTE is often fatal and preventive measures should be taken in the gynecologic field, especially when patients have the risk factors identified in this study. Since VTE is often present before surgery, preoperative screening is important and use of an IVC filter should be considered

The Sweet Potato Hornworm, Agrius convolvuli, as a New Experimental Insect : Continuous Rearing Using Artificial Diets

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Conductance of single 1,4-disubstituted benzene molecules anchored to Pt electrodes

The authors have studied the conductance of a 1,4-disubstituted isocyanide(–NC) or thiol(–SH) benzene molecule anchored to two Pt electrodes. A single molecular junction showing a well-defined conductance value (~3×10−2G0, G0=2e2/h) was fabricated with the Pt electrodes. The conductance of the molecular junction was one order higher than the previously documented value using Au electrodes. These observations could be explained by differences in the local density of states of the contact metal atom at the Fermi level and the extent of the hybridization and energy difference between the molecular and metal orbitals. Further insight into the binding strengths of the metal-anchoring group bond was obtained by statistically analyzing the stretching length of the molecular junction. ©2007 American Institute of Physic