Hokkaido University

About: Hokkaido University is a education organization based out in Sapporo, Hokkaidô, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 53925 authors who have published 115403 publications receiving 2651647 citations. The organization is also known as: Hokudai & Hokkaidō daigaku.

Synthesis of dimethyl carbonate and glycols from carbon dioxide, epoxides, and methanol using heterogeneous basic metal oxide catalysts with high activity and selectivity

Abstract: This paper gives a comprehensive report on a two-step synthesis of dimethyl carbonate (DMC) from epoxides, carbon dioxide and methanol using various basic metal oxide catalysts. The first step is the reaction of ethylene oxide or propylene oxide with CO 2 to form the corresponding cyclic carbonates, and the second step is the transesterification reaction of the cyclic carbonates with methanol to DMC and glycols. Among the catalysts examined, MgO is the most active and selective for both these reactions. Other alcohols can be used for the second step, but the activity decreases as the carbon number of the alcohol increases. Although a one-pot synthesis of DMC, i.e. the sequential reaction of the epoxide, CO 2 and methanol, is also possible with MgO, the selectivity is low because of the alcoholysis of the epoxide. In contrast with the reactions of ethylene oxide and propylene oxide, when styrene oxide is used for the first reaction and for the one-pot synthesis, mandelic acid is produced. Basic properties of the metal oxide catalysts were measured by temperature programmed desorption of CO 2 . The relationship between the catalytic performance and the basic property is discussed.

Mouse model of Prinzmetal angina by disruption of the inward rectifier Kir6.1.

Abstract: The inwardly rectifying K(+) channel Kir6.1 forms K(+) channels by coupling with a sulfonylurea receptor in reconstituted systems, but the physiological roles of Kir6.1-containing K(+) channels have not been determined. We report here that mice lacking the gene encoding Kir6.1 (known as Kcnj8) have a high rate of sudden death associated with spontaneous ST elevation followed by atrioventricular block as seen on an electrocardiogram. The K(+) channel opener pinacidil did not induce K(+) currents in vascular smooth-muscle cells of Kir6.1-null mice, and there was no vasodilation response to pinacidil. The administration of methylergometrine, a vasoconstrictive agent, elicited ST elevation followed by cardiac death in Kir6.1-null mice but not in wild-type mice, indicating a phenotype characterized by hypercontractility of coronary arteries and resembling Prinzmetal (or variant) angina in humans. The Kir6.1-containing K(+) channel is critical in the regulation of vascular tonus, especially in the coronary arteries, and its disruption may cause Prinzmetal angina.

Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy

Abstract: Study design This retrospective study analyzed the effects of cervical alignment on surgical results of expansive laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM). Objective To determine the limitation of posterior decompression by ELAP for CSM in the presence of local kyphosis. Summary of background data Several studies have reported that cervical malalignment affected surgical outcomes of ELAP. However, there has been no report to demonstrate crucial determinants of surgical outcomes of ELAP for CSM in relation to cervical sagittal alignment. Methods The study group comprised 114 patients who underwent ELAP for CSM. All were followed up for more than 2 years. The Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy (full score, 17 points) was used to evaluate surgical outcomes for each patient 2 years after surgery. Statistical analysis with multivariate logistic regression models was used to ascertain the risk factors affecting postoperative surgical outcomes. Results The average JOA scores were 9.9 points before surgery and 14 points 2 years after surgery. The recovery rate was 60.2%. Statistical analysis showed that signal intensity change on MRI and local kyphosis were the most crucial risk factors for poor surgical outcomes. Calculated with the logistic regression model, the highest risk of poor recovery was local kyphosis exceeding 13 degrees. Conclusions The influence of cervical malalignment on neurologic recovery after ELAP for CSM was shown. When patients have local kyphosis exceeding 13 degrees, anterior decompression or posterior correction of kyphosis as well as ELAP should be considered. Expansive laminoplasty for CSM is best indicated for patients with local kyphosis less than 13 degrees.

IKKα controls formation of the epidermis independently of NF-κB

Abstract: The IKKalpha and IKKbeta catalytic subunits of IkappaB kinase (IKK) share 51% amino-acid identity and similar biochemical activities: they both phosphorylate IkappaB proteins at serines that trigger their degradation. IKKalpha and IKKbeta differ, however, in their physiological functions. IKKbeta and the IKKgamma/NEMO regulatory subunit are required for activating NF-kappaB by pro-inflammatory stimuli and preventing apoptosis induced by tumour necrosis factor-alpha (refs 5,6,7,8,9,10,11). IKKalpha is dispensable for these functions, but is essential for developing the epidermis and its derivatives. The mammalian epidermis is composed of the basal, spinous, granular and cornified layers. Only basal keratinocytes can proliferate and give rise to differentiated derivatives, which on full maturation undergo enucleation to generate the cornified layer. Curiously, keratinocyte-specific inhibition of NF-kappaB, as in Ikkalpha-/- mice, results in epidermal thickening but does not block terminal differentiation. It has been proposed that the epidermal defect in Ikkalpha-/- mice may be due to the failed activation of NF-kappaB. Here we show that the unique function of IKKalpha in control of keratinocyte differentiation is not exerted through its IkappaB kinase activity or through NF-kappaB. Instead, IKKalpha controls production of a soluble factor that induces keratinocyte differentiation.

Anterior decompression and stabilization with the Kaneda device for thoracolumbar burst fractures associated with neurological deficits.

Abstract: One hundred and fifty consecutive patients who had a burst fracture of the thoracolumbar spine and associated neurological deficits were managed with a single-stage anterior spinal decompression, strut-grafting, and Kaneda spinal instrumentation. At a mean of eight years (range, five years to twelve years and eleven months) after the operation, radiographs showed successful fusion of the injured spinal segment in 140 patients (93 per cent). Ten patients had a pseudarthrosis, and all were managed successfully with posterior spinal instrumentation and a posterolateral arthrodesis. The percentage of the canal that was obstructed, as measured on computed tomography, improved from a preoperative mean of 47 per cent (range, 24 to 92 per cent) to a postoperative mean of 2 per cent (range, 0 to 8 per cent). Despite breakage of the Kaneda device in nine patients, removal of the implant was not necessary in any patient. None of the patients had iatrogenic neurological deficits. After the anterior decompression, the neurological function of 142 (95 per cent) of the 150 patients improved by at least one grade, as measured with a modification of the grading scale of Frankel et al. Fifty-six (72 per cent) of the seventy-eight patients who had preoperative paralysis or dysfunction of the bladder recovered completely. One hundred and twenty-five (96 per cent) of the 130 patients who were employed before the injury returned to work after the operation, and 112 (86 per cent) of them returned to their previous job without restrictions. We concluded that anterior decompression, strut- grafting, and fixation with the Kaneda device in patients who had a burst fracture of the thoracolumbar spine and associated neurological deficits yielded good radiographic and functional results.