Graphene nanosheet-grafted double-walled carbon nanotube hybrid nanostructures by two-step chemical vapor deposition and their application for ethanol detection.

Here, we present a facile technique for synthesis of graphene nanosheet (GNS)-grafted double-walled carbon nanotube (DWCNT) hybrid carbon nanostructures (here after referred to as G-DWCNTs) by directly growing GNSs along the sidewalls of DWCNTs using a two-step chemical vapor deposition (CVD). DWCNTs were synthesized by floating catalyst CVD at 1300 °C using ferrocene and thiophene dissolved in ethanol. Then, GNSs were grafted onto the synthesized DWCNT bundles by thermal CVD at 1300 °C using ethanol. The sharp-edged petal-like structure of GNSs were grown along the sidewalls of DWCNT bundles while maintaining the one-dimensional structure of DWCNT. Next, DWCNTs and G-DWCNTs were dispersed in ethanol, then deposited on the paper using vacuum filtration method and used for ethanol detection. G-DWCNTs sensor exhibited a 3-fold improvement in the response to ethanol vapor compared to the DWCNTs sensor. The sensing mechanism of DWCNTs and G-DWCNTs can be described in terms of charge transfer between the gas molecules and sensing material. These results demonstrate that the facile technique by two-step CVD method provides a promising approach for simple and low-cost technique to synthesize the hybrid nanostructure of GNSs and DWCNTs. The new hybrid carbon nanostructures are attractive for gas sensing application.

Graphite Whiskers Derived from Waste Coffee Grounds Treated at High Temperature.

Graphite whiskers (GWs) are obtained from coffee grounds (CGs) treated at 2500 °C for 1 h in the presence of Ar gas at 1 atm. The majority of the GWs formed inside the CGs shell are rod-like with a conical tip with diameter and length in the range between 1 to 3 µm and 4 to 10 µm, respectively. At first, the carbon layer might be grown in a turbostratic manner, and then progressively graphitized at higher temperature. The strong G' peak intensity might be induced by the disclination of graphitized carbon layers.

Corrigendum: Nitrogen-doped porous carbon monoliths from polyacrylonitrile (PAN) and carbon nanotubes as electrodes for supercapacitors.

This corrects the article DOI: 10.1038/srep40259.

Nitrogen-doped porous carbon monoliths from polyacrylonitrile (PAN) and carbon nanotubes as electrodes for supercapacitors.

Nitrogen-doped porous activated carbon monoliths (NDP-ACMs) have long been the most desirable materials for supercapacitors. Unique to the conventional template based Lewis acid/base activation methods, herein, we report on a simple yet practicable novel approach to production of the three-dimensional NDP-ACMs (3D-NDP-ACMs). Polyacrylonitrile (PAN) contained carbon nanotubes (CNTs), being pre-dispersed into a tubular level of dispersions, were used as the starting material and the 3D-NDP-ACMs were obtained via a template-free process. First, a continuous mesoporous PAN/CNT based 3D monolith was established by using a template-free temperature-induced phase separation (TTPS). Second, a nitrogen-doped 3D-ACM with a surface area of 613.8 m2/g and a pore volume 0.366 cm3/g was obtained. A typical supercapacitor with our 3D-NDP-ACMs as the functioning electrodes gave a specific capacitance stabilized at 216 F/g even after 3000 cycles, demonstrating the advantageous performance of the PAN/CNT based 3D-NDP-ACMs.

[Successful pain control by continuous epidural infusion of ropivacaine for a pregnant woman with biliary colic].

This report describes a pregnant woman with common bile duct stones whose colic was successfully treated by prolonged continuous epidural infusion of ropivacaine. A 32-year-old woman in the 26th week pregnancy complained of severe abdominal pain due to common bile duct stones. We adopted ropivacaine for infusion into the epidural space using patient controlled analgesia system considering fetoplacental circulation. We administered the solution successfully for 3 weeks, but we observed that the effectiveness of ropivacaine became reduced. This suggests that tachyphilaxis to ropivacaine might have developed by its long-term infusion.

The combination of serum trefoil factor 3 and pepsinogen testing is a valid non-endoscopic biomarker for predicting the presence of gastric cancer: a new marker for gastric cancer risk.

BACKGROUND: A valid biomarker for predicting the presence of gastric cancer may contribute to reducing deaths from this disease. Although pepsinogen (PG) testing has been introduced as a predictor, its predictive power is not satisfactory. We examined whether serum trefoil factor (TFF) could be a non-endoscopic predictor of the presence of gastric cancer. METHODS: Gastric cancer patients who underwent preoperative endoscopy were sequentially recruited. Individuals who underwent a thorough medical checkup were enrolled as non-cancer controls. Serum levels of TFF1, TFF2, TFF3, Helicobacter pylori antibody, PG I, and PG II were examined. RESULTS: We studied 192 gastric cancer patients aged 64.3 ± 9.7 years and 1254 non-cancer controls aged 52.3 ± 12.4 years. In the age/gender-matched analysis (187 cases and 561 controls), significant relationships were demonstrated between gastric cancer presence and TFF3 (P < 0.0001), the PGI/II ratio (P < 0.0001), H. pylori antibody (P = 0.001), TFF1 (P = 0.012), and TFF2 (P = 0.020). The area under the receiver-operating characteristic curve for predicting gastric cancer presence was comparably high for all factors (0.893) and for the combination of TFF3 and the PG test (0.883), but was significantly (P < 0.0001) lower for the PG test alone (0.823). A positive PG test showed a sensitivity of 67% and specificity of 82%, whereas a combination of TFF3 and PG testing showed a sensitivity of 80% and specificity of 80% in predicting the presence of gastric cancer. CONCLUSION: The combination of serum TFF3 and PG testing might be a valid non-endoscopic biomarker for predicting the presence of gastric cancer.