PME (Palm oil methyl ester) is a promising alternative fuel among biodiesels, because palm oil is the most produced feedstock and its yield is the highest among vegetable oil crops. However, PME has ...a serious drawback in its relatively high pour point. The aim of this investigation is to extend the range of utilization of PME by improving its low temperature fluidity. The present study used three kinds of blended fuels composed of PME/gas oil/1-butanol to show the effect of lower pour points. Neat PME has a pour point of 19 °C, for a PME blend with 20% PME (PME20) the pour point is −5 °C, and with 40 mass% 1-butanol blended into the PME20 the pour point is −10 °C. Using four kinds of PME/gas oil blends as the base fuels the influence of 1-butanol addition on the engine performance, combustion characteristics, and exhaust emissions of a small single cylinder DI (direct injection) diesel engine was examined. The brake thermal efficiency of the base fuels changed little when 1-butanol was added up to 40 mass%. The results also showed that at the rated output condition the smoke emissions decreased considerably with increasing 1-butanol addition ratios.
The mechanism of biomaterial-associated thrombosis has not been fully elucidated. It is believed that surface roughness of biomaterials is a key factor in influencing thrombogenicity. Diamond-like ...carbon (DLC) is being considered for widespread clinical use as a surface coating for cardiovascular devices. We previously reported that fluorine doping in DLC films (F-DLC) markedly inhibits platelet adhesion and activation in human blood. To evaluate the effects of surface roughness of coatings on thrombus formation, DLC and F-DLC films were deposited on the three different roughness-controlled polycarbonate (PC) substrates, and platelet adhesion and activation was investigated on each substrate. The surface roughness of DLC-coated PC and F-DLC-coated PC ranged from 4.1 nm to 97 nm. In this range, there were no significant differences in the platelet-covered area among the three grades of differing surface roughness for each coated surface. However, evaluation of the F-DLC films showed significant reductions in platelet adhesion and activation when compared with DLC films for every grade of roughness, suggesting that the inherent chemical characteristics of the surface, such as wettability, interfacial free energy and higher ratios of albumin/fibrinogen adsorption, might be more important in the mechanism of F-DLC non-thrombogenicity.
Intratumoral hemorrhage occurs frequently in pituitary macroadenoma and manifests as pituitary apoplexy and recent or old silent hemorrhage. T2*-weighted gradient-echo (GE) MR imaging is the most ...sensitive sequence for the detection of acute and old intracranial hemorrhage. T2*-weighted GE MR imaging was used to investigate intratumoral hemorrhage in pituitary macroadenomas.
Twenty-five consecutive patients who underwent total or subtotal resection of pituitary macroadenoma with heights from 17 to 53 mm, including 1 patient with classic pituitary apoplexy, underwent MR imaging before surgery, including T2*-weighted GE MR imaging. For histologic assessment of the hemorrhage in whole surgical specimens, we used hematoxylin-eosin staining.
T2*-weighted GE MR imaging detected various types of dark lesions, such as "rim," "mass," "spot," and "diffuse" and combinations, indicating clinical and subclinical intratumoral hemorrhage in 12 of the 25 patients. The presence of intratumoral dark lesions on T2*-weighted GE MR imaging correlated significantly with the hemorrhagic findings on T1- and T2-weighted MR imaging (P < .02 and <.01, respectively), and the surgical and histologic hemorrhagic findings (P < .001 and <.001, respectively).
T2*-weighted GE MR imaging could detect intratumoral hemorrhage in pituitary adenomas as various dark appearances. Therefore, this technique might be useful for the assessment of recent and old intratumoral hemorrhagic events in patients with pituitary macroadenomas.
The non-thrombogenicity of oxygen-plasma-treated DLC films was investigated as surface coatings for medical devices. DLC films were deposited on polycarbonate substrates by a radio frequency plasma ...enhanced chemical vapor deposition method using acetylene gas. The deposited DLC films were then treated with plasma of oxygen gas at powers of 15
W, 50
W, and 200
W. Wettability was evaluated by water contact angle measurements and the changes in surface chemistry and roughness were examined by X-ray photoelectron spectroscopy and atomic force microscope analysis, respectively. Each oxygen-plasma-treated DLC film exhibited a hydrophilic nature with water contact angles of 11.1°, 17.7° and 36.8°. The non-thrombogenicity of the samples was evaluated through the incubation with platelet-rich plasma isolated from human whole blood. Non-thrombogenic properties dramatically improved for both 15
W- and 50
W-oxygen-plasma-treated DLC films. These results demonstrate that the oxygen plasma treatment at lower powers promotes the non-thrombogenicity of DLC films with highly hydrophilic surfaces.
Bias favouring publication of research with "positive" results over studies with "negative" results is widely suspected. The present investigation addressed this problem in the field of neurosurgery ...through a review of recent literature concerning outcome of surgery for unruptured intracranial aneurysms.
A Medline search was performed seeking case series of surgical treatment for unruptured intracranial aneurysms that analyzed 50 or more patients. Ten type I studies (retrospective studies from a single institution; 1457 patients) met these entry criteria. In general, type I studies reported excellent surgical outcome, with mean combined mortality and morbidity of 7.8% (95% confidence interval (CI), 6.4% to 9.2%). We found 4 multicenter or community-based studies (type II studies; 5401 patients). Mean combined mortality and morbidity in the type II studies was 20.3% (95% CI, 19.2% to 21.4%), much higher than in type I studies. Relative risk was 2.6 (95% CI, 2.2 to 3.1) for patients in type II studies compared with those in type I studies. Two meta-analyses (type III studies) described combined mortality and morbidity of 5.0% and 12.7%, essentially corresponding to results of type I studies.
Publication bias is present in the neurosurgical literature. Studies with an excellent surgical outcome are more likely to be published than those with an average outcome. Conclusions of literature reviews or meta-analyses based on published work therefore may be misleading. The solution to the problem would be community-based prospective registration of all patients who underwent surgery, providing a sampling frame free from publication bias.
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