Electroactive polymer actuator with high response speed through anisotropic surface roughening by plasma etching

Plasma etching was performed to improve displacement and response speed of IPMC actuator through homogeneous roughening and anisotropic surface treatment. We found that the anisotropic surface treatment by plasma etching of Nafion in the pre-treatment process gave the response speed and displacement of resulting IPMC which was 2 times faster and 1.5 times larger than those manufactured by the sandblasting, respectively.

Temporal evolution of urban wet weather pollution: analysis of PCB and PAH in sediment cores from Lake Bourget, France

In order to evaluate the historical impact of urban stormwater runoff on a lacustrine environment, eight sediment cores were collected in October 2006 in Lake Bourget (Savoie, France). Sediment samples were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorobyphenyls (PCB) in order to correlate the vertical profiles of contamination and the evolution of the urbanisation on the watershed for the last 100 years. Overall, we observe that vertical profiles of PCB and PAH concentrations in Lake Bourget are showing a downward trend, probably resulting from the pollution control measures. Concentrations of PCB and PAH measured in surface sediments are approximately 5-10 fold less than maximal concentrations found in the cores. Maximal PAH concentrations were found at the bottom of the cores ( approximately 40 cm) which approximately correspond to the beginning of the 20th century. Maximal PCB concentrations measured in cores L5 and L6 are respectively 850 and 790 microg/g dw (dryweight). The peak of PCB corresponds to the maximum of PCB production and consumption in the 1970s. In surface sediments total PCB concentrations range between 47 and 79 microg/kg dw. Those concentrations are particularly high compared to other values measured in lake sediments and highlight the problem of a local source of PCB contamination in the watershed. General trends were observed, yet the part of urban stormwater runoff in the total contamination could not be determined.

Spinor dynamics in an antiferromagnetic spin-1 condensate

We observe coherent spin oscillations in an antiferromagnetic spin-1 Bose-Einstein condensate of sodium. The variation of the spin oscillations with magnetic field shows a clear signature of nonlinearity, in agreement with theory, which also predicts anharmonic oscillations near a critical magnetic field. Measurements of the magnetic phase diagram agree with predictions made in the approximation of a single spatial mode. The oscillation period yields the best measurement to date of the sodium spin-dependent interaction coefficient, determining that the difference between the sodium spin-dependent s-wave scattering lengths a(f=2) - a(f=0) is 2.47+/-0.27 Bohr radii.

Comparing study of positron emission tomography and ultrasonography in the detection of axillary lymph node metastasis in patients with early stage breast cancer

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Background: The current status of axillary lymph node is the most important prognostic factor in breast cancer. Axillary lymph node dissection (ALND) is currently the standard option for assessment of axillary lymph nodes. Positron emission tomography - computerized tomography (PET-CT) imaging and breast sonography are a noninvasive imaging modality that can detect malignant lymph node. The purpose of this study was to evaluate the clinical usefulness of axillary lymph node staging by means of PET-CT imaging compare with breast sonography in breast cancer. Methods: This study involves 129 breast cancer patients and clinically negative axillary node. All patients had whole body PET-CT imaging and breast sonography before SLN biopsy. After SLN biopsy, all patients underwent complete ALND. Axillary lymph nodes were evaluated by standard hematoxylin and eosin staining techniques, while sentinel nodes were further examined for micrometastatic disease. The findings of PET-CT imaging and breast sonography of 129 patients were compared with pathologic findings after operation. Diagnostic accuracy was evaluated applying ROC curve areas. Results: The sensitivity of PET-CT imaging was 60.0%; specificity and accuracy were 83.6% and 73.4%, respectively. The sensitivity, specificity and accuracy of breast sonography were 61.8%, 89.0%, and 77.3% respectively. The SUVs of axillary lymph node ranged from 0.0 to 7.01. Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For involvement of axillary lymph node, PET-CT imaging had the area under the curve of 0.735, breast sonography one of 0.769. Conclusions: Axillary lymph node staging using PET-CT imaging is inferior to the breast sonography in early stage of breast cancer patients. Our study reveals the value of PET-CT imaging is not good compare to the breast sonography in the detection of axillary lymph nodes metastasis in patients with early breast cancer.

No significant financial relationships to disclose.

Synergistic tumoricidal effect between celecoxib and gabexate mesilate on the human breast cancer cells

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Background: Selective cyclooxygenase 2 (COX2) inhibitors, including celecoxib, has shown its antitumor effects against various cancers including breast cancer. Gabexate mesilate (GM) can be found to have anti-cancer activities against tumors such as colon cancer. We tried to determine whether synergism can exist between GM and celecoxib against human breast cancer cells. Methods: MCF7/Her18 (estrogen receptor positive) and MDA-MB-436 (estrogen receptor negative) human breast cancer cells were used. Celecoxib and GM were added into the culture media at a dose of 30 and 50 μM for estrogen receptor (ER) (+) cells and 50 and 75 μM for ER (-) cells. Cellular proliferation assays wer performed and trypan blue exclusion method was adopted to count the viable cells after culture. Cell cycle analysis and fluorescein-assorted cell sortings were done to check the cell cycle changes after treatment. Immunoblotting using Akt, phosphorylated Akt (p- Akt), β-catenin, COX2 and VEGF was done to evaluate changes in expression of these proteins. Results: Combination treatment group showed significantly enhanced tumoricidal effect than either mono-treatment group on cellular proliferation study. Combined treatment yielded more G1 phase population and G2-M phase cells. (p<0.05) The level of Akt, p-Akt, VEGF, COX2 expression were decreased more significantly than either mono-treatment group. (p<0.05) Conclusions: We think that there could be synergistic effect between GM and celecoxib on the human breast cancer cells. Either drug has been used for many cases without significant problem, and can be tried for further ex vivo studies to determine synergistic effects between them. Possible antiangiogenentic actions after the combination should be evaluated thoroughly in other cell lines to get more preclinical data.

No significant financial relationships to disclose.

Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system as used for surgery of distal anterior cerebral artery (DACA) aneurysm.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3-10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5-1.5 mm (mean: 0.88 mm). The neuronavigation system provided real-time presentation of the DACA and the aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system used for surgery of distal anterior cerebral artery (DACA) aneurysms.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision2 neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3 to 10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5 to 1.5 mm (mean: 0.88). The neuronavigation system provided real-time presentation of the DACA aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.