Hydroupgrading of Bio-Oil Over PtMg/KIT-6 Catalysts.

The objective of this study is to evaluate the catalytic potential of PtMg/Al-KIT-6 during the hydroupgrading of a mixture composed of C15-C18 alkane as a model compound of bio-oil obtained by a hydrodeoxygenation of palm oil. Al-KIT-6 was prepared through a post-alumination method using KIT-6, after which platinum and magnesium precursors were impregnated onto the synthesized Al-KIT-6. PtMg/Al-KIT-6 catalysts were shown to have a well-arranged mesoporous structure, a large surface area, and a large pore size. The jet-fuel yield (55-59%) in the hydroupgrading of the long-chain n-alkane mixture over PtMg/Al-KIT-6 catalysts was much higher than that over the PtMg/KIT-6 catalyst, which could be ascribed to the higher number of acid sites of the PtMg/Al-KIT-6 catalysts. The highest isomer selectivity of the PtMg/Al-KIT-6(20) catalyst can be attributed to the strong acidity as well as the abundance of acid sites. PtMg/Al-KIT-6 catalysts can be effective catalysts for producing jet fuel through the hydroupgrading of bio-oil.

Relationship between New Osteoporotic Vertebral Fracture and Instrumented Lumbar Arthrodesis.

STUDY DESIGN: Retrospective study. PURPOSE: To evaluate the relationship between a new osteoporotic vertebral fracture and instrumented lumbar arthrodesis. OVERVIEW OF LITERATURE: In contrast to the growing recognition of the importance of adjacent segment disease after lumbar arthrodesis, relatively little attention has been paid to the relationship between osteoporotic vertebral fractures and instrumented lumbar arthrodesis. METHODS: Twenty five patients with a thoracolumbar vertebral fracture following instrumented arthrodesis for degenerative lumbar disorders (study group) were investigated. The influence of instrumented lumbar arthrodesis was examined by comparing the bone mineral density (BMD) of the femoral neck in the study group with that of 28 patients (control group) who had sustained a simple osteoporotic vertebral fracture. The fracture after instrumented arthrodesis was diagnosed at a mean 47 months (range, 7 to 100 months) after the surgery. RESULTS: There was a relatively better BMD in the study group, 0.67 ± 0.12 g/cm(2) compared to the control group, 0.60 ± 0.13 g/cm(2) (p = 0.013). The level of back pain improved from a mean of 7.5 ± 1.0 at the time of the fracture to a mean of 4.9 ± 2.0 at 1 year after the fracture (p = 0.001). However, 12 (48%) patients complained of severe back pain 1 year after the fracture. There was negative correlation between the BMD of the femoral neck and back pain at the last follow up (r = - 0.455, p = 0.022). CONCLUSIONS: Osteoporotic vertebral fractures after instrumented arthrodesis contribute to the aggravation of back pain and the final outcome of degenerative lumbar disorders. Therefore, it is important to examine the possibility of new osteoporotic vertebral fractures for new-onset back pain after lumbar instrumented arthrodesis.