Study on preparation and characterization of monolithic silica capillary columns for high separation efficiency in high performance liquid chromatography

This thesis addresses the preparation and characterization of monolithic silica capillary columns to examine column performance in high performance liquid chromatography. The monolithic silica capillaries and monolithic silica rods, prepared under similar preparation conditions, were evaluated. The most important findings in this thesis are as follows: First, it was successful to control retention ability and retention selectivity of solutes in reversed-phase liquid chromatography by changing the composition of the preparation feed solution. The hybrid columns prepared with tetramethoxysilane and methyltrimethoxysilane under the present preparation conditions were able to show higher column efficiency than the hybrid columns reported previously, while maintaining the retention factors in a similar range by reducing the concentration of methyltrimethoxysilane and increasing the total silane concentration in the feed solution. Second, the effects of hydrothermal treatments at 80 °C and 120 °C on mesoporosity of monolithic silica were investigated. The results of pore characterization of the capillary columns by inverse size exclusion chromatography were compatible with those of the nitrogen physisorption measurements performed on the silica rods regarding pore size distribution. The effect of hydrothermal treatment or silica precursor on mesopore size and surface area could be detected. In reversed-phase liquid chromatography, the hybrid column treated at 80 °C showed low column efficiency for large molecules (e.g. insulin), but not for small molecules (alkylbenzenes), because of the absence of the additional hydrothermal treatment at 120 °C. In contrast, for pure silica columns produced with tetramethoxysilane only, no significant difference in column efficiency was observable. The aforementioned difference supported the results of the examination by inverse size exclusion chromatography and the nitrogen physisorption measurement performed on the hybrid silica, treated at 80 °C only, showing the presence of a large volume of small pores below 60 Å. Consequently, it was suggested that the hydrothermal treatment at 120 °C has a stronger influence on the hybrid column in comparison with the pure silica column, to provide higher column efficiency with an increase in molecular size of solute

Japanese Monetary Policy during the Collapse of the Bubble Economy: A View of Policymaking under Uncertainty

Focusing on policymaking under uncertainty, we analyze the monetary policy of the Bank of Japan (BOJ) in the early 1990s, when the bubble economy collapsed. Conducting stochastic simulations with a large- scale macroeconomic model of the Japanese economy, we find that the BOJf s monetary policy at that time was essentially optimal under uncertainty about the policy multiplier. On the other hand, we also find that the BOJ's policy was not optimal under uncertainty about inflation dynamics, and that a more aggressive policy response than actually implemented would have been needed. Thus, optimal monetary policy differs greatly depending upon which type of uncertainty is emphasized. Taking into account the fact that overcoming deflation became an important issue from the latter 1990s, it is possible to argue that during the early 1990s the BOJ should have placed greater emphasis on uncertainty about inflation dynamics and implemented a more aggressive monetary policy. The result from a counterfactual simulation indicates that the inflation rate and the real growth rate would have been higher to some extent if the BOJ had implemented a more accommodative policy during the early 1990s. However, the simulation result also suggests that the effects would have been limited, and that an accommodative monetary policy itself would not have changed the overall image of the prolonged stagnation of the Japanese economy during the 1990s.Collapse of the bubble economy; Monetary policy; Uncertainty

Nappe structure of the Asaji metamorphic rocks, with special reference to geological structure of the basement complexes in Kyushu

The Asaji metamorphic rocks in the Notsuharu area, Oita Prefecture are composed mainly of pelitic rock, psammitic rock, chert, basic rock and serpentinite. Thelast forms serpentinite melange zone, including many blocks of metamorphic rocks, and shows an overturned fold of SE vergence with the NE plunging fold axis and NNW dipping axial plane. The metamorphic rocks are divided into two groups, separated from each other by the melange zone. One occupies the horizon below the melange zone and the other above. Carbonaceous materials from 32 pelitic rock samples were examined by TAGIRI'S (1981) X-ray diffraction method in order to compare their metamorphic grade. The results show the distinct discontinuity of metamorphic grade between two groups of both sides of the melange zone. It is concluded that the sequence above the melange zone is a nappe (Hikata nappe), and the SE vergenced overturned fold has been formed during the formation of the nappe structure. The Asaji metamorphic rocks are considered to be long to the Ryoke metamorphic rocks. In Kyushu, apparent continuity of the Sambagawa belt terminate at the Saga-noseki Peninsula just to the east of the Notsuharu area. It appears from the above that the nappe of the Ryoke metamophic rocks such as the Hikata nappe overlies the Sambagawa belt in Kyushu. Incidentally, the Nagasaki metamophic rocks would blong to the Sambagawa metamorphic rocks

Perioperative Management for Full-Endoscopic Lumbar Discectomy: Consideration From the Perspective of Preventing Complication

In recent years, full-endoscopic discectomy (FED) has expanded its range of indications with the development of devices and various techniques. The advantage of FED over conventional surgery is that it is a minimally invasive procedure. However, intraoperative and postoperative precautions must be taken to prevent complications. It is necessary to avoid complications that could compromise the outcome of the procedure. Effective perioperative management is necessary to avoid complications; however, there is no set view for perioperative management in FED. In this study, we perform a literature review to examine the effectiveness of perioperative management methods for FED. The key to ensuring the efficacy and minimal invasiveness of FED is prevention of complications. Based on the result and literature review, we believe that the most manageable postoperative management after FED is prevention of recurrent disc herniation and hematoma formation. A drain should be placed to prevent postoperative hematoma formation. It is advisable to evaluate the patient’s symptoms and monitor C-reactive protein and erythrocyte sedimentation rate levels during the first week after surgery. Postoperative antibiotics were administered for 1 day

A new nail-plate for treatment of fracture of the neck of the femur

Operative treatment of fractures of the neck and trochanter of the femur does not always produce a satisfactory result. This is usually due to biomechanical problems with the available internal fixation methods. We studied the anatomy of the neck of the femur by roentgenograms and sectional specimens from 70 cadavers. In addition, various nail-plates were subjected to buckling tests and, by simultaneously attaching a strain-gauge, stress distribution was calculated. The results of these preliminary studies were then used to design a new nail-plate better than those available at present. Testing of this new nail-plate confirmed that it had a strength equal to that of the Holt nail-plate (the strongest of the available nail-plates).</p

Assessing patterns of T2/T1rho change in grade 1 cartilage lesions of the distal femur using an angle/layer dependent approach.

PURPOSE:To assess changes in the patterns of T2 and T1rho values within grade 1 cartilage lesions of osteoarthritis (OA) patients compared to healthy controls. MATERIALS AND METHODS:Twenty healthy knees and 25 OA knees were examined on a 3 T scanner. Areas of signal heterogeneity within the cartilage of the distal femur were identified using fat suppressed proton density-weighted imagines. T2 and T1rho values in each OA patient with grade 1 lesions were compared to average T2 and T1rho values of the corresponding areas in healthy subjects. RESULTS:A total of 28 areas including grade 1 lesion were identified. Compared to normal cartilage, the majority of grade 1 cartilage lesions demonstrated either no significant change or a statistically significant increase in both T2 values (18/28, 64%) and T1rho values (23/28, 82%). Compared to T2, T1rho demonstrated a greater proportion of statistically significantly higher values in OA patients than those from the normal controls. However, T2 and T1rho values in grade 1 lesions can be decreased, or demonstrate mixed patterns compared to those in healthy cartilage. CONCLUSION:Our results suggest that early degenerative cartilage lesions can demonstrate various patterns of T2 and T1rho changes

Development of detection device for dugong calls

December 15-17, 2007, Royal Phuket City Hotel, Phuket, ThailandAn acoustical approach for research on marine mammals has been a very active research method in recent years. Dugong (Dugong dugon) is one of the highly endangered species, which are strictly-marine herbivorous and mainly inhabit coastal areas. In order to detect dugong calls from recorded data, several algorithms have been adapted by researchers in the analyzing process. However, the number of misses in the detection is still non-zero. The sound of snapping shrimp recorded in a wide range (2-300 kHz) is one of the main background noises that makes the detection of dugong calls difficult in warm shallow waters. Impulse elimination was employed in the system to get rid of the snapping shrimp noise. In order to improve the performance of the detection system by increasing the detection rate and decreasing the number of misses, two new algorithms were tested in the experiment. The experimental results for the new algorithms including impulse elimination and the cepstrum method are presented in this paper

Quantitative Evaluation of Liver Function with Use of Gadoxetate Disodium-enhanced MR Imaging

Purpose: To determine whether liver function correlating with indocyanine green (ICG) clearance could be estimated quantitatively from gadoxetate disodium-enhanced magnetic resonance (MR) images. Materials and Methods: This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Twenty-three consecutive patients who underwent an ICG clearance test and gadoxetate disodium-enhanced MR imaging with the same parameters as were used for a preoperative examination were chosen. The hepatocellular uptake index (HUI) from liver volume (V(L)) and mean signal intensity of the liver on contrastenhanced T1-weighted images with fat suppression (L(20)) and mean signal intensity of the spleen on contrastenhanced T1-weighted images with fat suppression (S(20)) on 3D gradient-echo T1-weighted images with fat suppression obtained at 20 minutes after gadoxetate disodium (0.025 mmol per kilogram of body weight) administration was determined with the following equation: V(L)[(L(20)/S(20)) 2 1]. The correlation of the plasma disappearance rate of ICG (ICG-PDR) and various factors derived from MR imaging, including HUI, iron and fat deposition in the liver and spleen, and spleen volume (V(S)), were evaluated with stepwise multiple regression analysis. The difference between the ratio of the remnant HUI to the HUI of the total liver (rHUI/HUI) and ratio of the liver remnant V(L) to the total V(L)(rV(L)/V(L)) was evaluated in four patients who had segmental heterogeneity of liver function. Results: HUI and V(S) were the factors significantly correlated with ICG-PDR (R = 0.87). The mean value and its 95% confidence interval were 0.18 and 0.01 to 0.34, respectively, for the following calculation: (rHUI/HUI) 2 (rV(L)/V(L)). Conclusion: The liver function correlating with ICG-PDR can be estimated quantitatively from the signal intensities and the volumes of the liver and spleen on gadoxetate disodium-enhanced MR images, which may improve the estimation of segmental liver function. (C) RSNA, 2011ArticleRADIOLOGY. 260(3):727-733 (2011)journal articl