This paper describes two topics. One is a decrease in the fraction of methyl oleate ester in biodiesel fuel. study of the effects of biodiesel fuel physical properties on injection characteristics and spray behaviour. The study was done via numerical simulation of the injecKey words: biodiesel fuel, DI-CI engine, injection, combustion, emission tion system and via laser-sheet imaging of the spray. The second topic is a study of the effects of the constituents of biodiesel fuel on combustion and exhaust emis-
The current paper describes two topics. The first is a study of the effect of fatty acid methyl ester content in biodiesel on characteristics of oxidation stability as quality parameters, including peroxide value, acid value, kinematic viscosity, and induction period obtained from a Rancimat test. The second is a study of the effect of biodiesel oxidation on diesel combustion and emission characteristics. An accelerated oxidation stability test was conducted by the Rancimat test method on methyl esters with different unsaturated fatty acid components. The unsaturated fatty acid components exert a large influence on oxidation deterioration as well as thermal and auto-oxidation stability. In addition, characteristics of oxidation were obtained from a thermal oxidation test using a tank equipped with an injection system test rig. These experiments clarified relationships between oxidation quality parameters. The autoignition characteristics of deliberately oxidized biodiesel were analysed by means of the constant-volume combustion method. Engine bench tests were also conducted on a single-cylinder engine. These experiments employed methyl ester made from soya bean oil as biodiesel. Use of an oxidized biodiesel was found to increase combustion pressure and temperatures, resulting in increased NO x emission; however, CO emission and smoke are decreased without any loss in fuel consumption rate.
With the aging of the population in developed countries, spine surgeons have recently been more likely to encounter elderly patients in need of treatment. This study investigated whether decompression surgery for cervical spondylotic myelopathy (CSM) in elderly patients aged 80 years or older would likely be a reasonable treatment. We retrospectively reviewed 605 consecutive patients with cervical myelopathy who underwent decompression surgery between 2004 and 2008. Patients with other conditions that could affect functional status or compression factors other than spondylosis were excluded from this study. Of the remaining 189 patients, 161 with CSM whose condition could be evaluated 6 months after surgery were analyzed. The patients were divided into two age groups: 80 years or older (Group A, 37 patients) and younger than 80 years of age (Group B, 124 patients). We evaluated the differences in symptom duration, clinical data, involved levels, surgical outcome, comorbidities, and postoperative complications between the two groups. The symptom duration was significantly shorter in Group A. The average JOA scores preoperatively and 6 months postoperatively were significantly lower in Group A; however, there was no significant difference in the recovery ratio. There were no significant differences in the percentages of patients with comorbidities or those with postoperative complications. Elderly patients aged 80 years or older regained approximately 40% of their function postoperatively, and the incidence of postoperative complication was similar to that in younger patients. Since this age group shows a rapid deterioration after onset, prompt decompression surgery is required.
There have been few reports describing cytokines in the cerebrospinal fluid (CSF) of patients with spinal degenerative disorders. This study investigated whether interleukin-1b (IL-1b), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-a) could be detected in CSF of patients with cervical myelopathy or lumbar radiculopathy and whether the concentrations of those cytokines correlated with the severity of disease conditions. CSF samples were obtained from 21 patients with cervical myelopathy (Group M) and 19 patients with lumbar radiculopathy (Group R), and six volunteers (control). The concentration of IL-6 was significantly higher in Groups M and R than in the control, possibly demonstrating spinal cord and nerve root damage, respectively. However, TNF-a was lower than the detection limit. IL-1b was detected in only five samples from three patients in Group M and two volunteers in the control. The concentrations of IL-6 did not show any correlation with symptom duration, the scoring system by the Japanese Orthopaedic Association, or the duration of nerve root block. There is a possibility that the concentration of inflammatory cytokines in CSF can indicate certain pathological aspects of cervical myelopathy or lumbar radiculopathy.
We retrospectively reviewed the medical charts of 210 consecutive patients treated for spinal infection in Tottori University Hospital in Japan between 1956 and 2005. Until 1995, spinal infection was under control in this series; however, during the last decade, it has been on the rise. Male predominance had been gradually progressing, and 69% of the patients were male during the last decade. Patients with spinal infection were aging, and the ratio of immunocompromised hosts dramatically increased to 53%. Until 1995, the percentage of patients with tuberculous spondylitis had been declining; however, the incidence has been on the rise during the last ten years. The organism was detected in 64% of patients treated between 1996 and 2005, of which Staphylococcus aureus was detected in 49%. Moreover, methicillin-resistant S. aureus was detected in 61% of patients with S. aureus. There were no immigrants or cases with human immunodeficiency virus in this series.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.