Fast and precise method for HPLC-size exclusion chromatography with UV and TOC (NDIR) detection: importance of multiple detectors to evaluate the characteristics of dissolved organic matter

A new type of high-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) system with ultraviolet (UV) absorbance detection and non-dispersive infrared (NDIR) detection of total organic carbon is described. The introduction of an online degassing tube and a low-volume HPLC column helped to reduce the analytical time and increase the sensitivity of the SEC system. This study is the first in which linear calibration curves (R² > 0.99) were obtained for both UV absorbance and NDIR data for polystyrene sulfonate standards, which are the most suitable standards for molecular size analysis of aquatic humic substances as well as dissolved organic matter (DOM). Using the calibration curves, the molecular size distribution of DOM in water collected from Lake Kasumigaura and in pore water from lake sediments was estimated. Most of the DOM had a molecular weight less than 4000 Daltons (Da), and the amount of low-molecular-weight DOM (∼2000 Da) with low UV absorbance increased with depth in the sediment pore water. This result shows the importance of combining quantitative analysis by NDIR detection with qualitative analysis by UV detection to determine the chemical and physical properties of DOM. The possible sources and reactivity of DOM in Lake Kasumigaura and its sediment pore water are also discussed.     

Reaction of coal with quinoline during extraction

Yubari coal vitrite was extracted with quinoline at 420° C for 0–4 h and the products were separated into several fractions. Quinoline solubles (QS) and insolubles (QI) increased with time and the total recovered weight became nearly 200% of the original weight of the coal. A large part of this weight increase was due to the contribution of the formation of biquinoline and to quinoline addition to coal. Depolymerization to smaller molecules and polymerization to QI took place simultaneously via the addition of quinoline and the production of biquinoline.     

Syntheses and preventive effects of analogues related to 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy)vitamin D3 (ED-71) on bone mineral loss in ovariectomized rats

Analogues related to 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy)vitamin D3 (ED-71) (2), 26,27-dimethyl ED-71 (3) and 26,27-diethyl ED-71 (4), were synthesized from lithocholic acid (5). In the study of the preventive effects of these analogues and ED-71 (2) on bone mineral loss in ovariectomized rats, 26,27-dimethyl ED-71 (3) showed the most potent activity.     

Polarization-insensitive optical amplifier withtensile-strained-barrier MQW structure

A new approach to achieving a polarization-insensitive semiconductor optical amplifier is presented. The active layer consists of a tensile-strained-barrier MQW structure that enhances TM mode gain. Polarization sensitivity below 0.5 dB is realized at a wavelength of 1.56 μm. A signal gain of 27.5 dB is obtained along with a saturation output power of 14 dBm. Deriving the refractive indices of well and barrier layers from both experiment and theory, we succeed in separation of the effect of the confinement factor and the gain coefficient. It is determined that TM mode gain enhancement in this structure is primarily due to the increase in the confinement factor     

Acoustic measurement of the respiratory system-an acoustic pneumograph

Gangrenous bowel most often results from hernia, adhesions and mesenteric insufficiency. The overall mortality rate for 151 cases was 37%. This figure was 20% for hernia, 23% for adhesions and 74% for mesenteric insufficiency. In the latter category where bowel resection was feasable the mortality rate was 40%. Other causes of bowel gangrene had a mortality rate of 28%. In many instances the pathophysiologic processes were of such a nature that current medical expertise has not reached a level of development to effectively cope with the situation. There were, however, a significant number of cases where survival may have been achieved had it not been for deficiences on the part of the patient, the primary health care personnel or those in attendence at the referral center. The basic keystone for a successful outcome in the management of patients with the gangrenous bowel problem is early surgical intervention. All will be lost if patient exposure to this source of lethal toxins is allowed to proceed to an irreversible stage. Liberal antibiotic administration probably postpones the arrival of intractable hypotension. Other factors which can be expected to improve the survival rate include minimization of technical errors, repair of incidental hernias, elemination of dependence upon nasogastric tubes for the definitive management of patients with complete bowel obstruction (with one or two exceptions), and a firm commitment to the diligent pursuit and early definitive management of postoperative complications.     

Crystal structure of a major seed storage protein, 11S proglobulin, from Amaranthus hypochondriacus: insight into its physico-chemical properties

Amaranth is a crop known for its high quality proteins. 11S Globulin is one of the most abundant and important storage proteins of the amaranth grain. Here, we report the crystal structure of amaranth 11S proglobulin at a final resolution of 2.28 Å. It belonged to the space group P6₃ with cell dimensions a = b = 96.6, c = 75.0 Å. It contains one asymmetric unit consisting of 372 residues and 100 water molecules. Disordered regions in the model approximately correspond to the variable regions of the 11S globulins. The structure has an extended α-helix and β-barrel domains at both N-terminal and C-terminal regions, which are characteristic of the 11S and 7S globulins. The three dimensional structure suggests that its high thermal stability is due to the cumulative effects of many factors and its good emulsifying property depended on the balance between its surface hydrophobicity and hydrophilicity.     

Experimental study of low-cycle fatigue of pipe elbows with local wall thinning and life estimation using finite element analysis

Low-cycle fatigue tests were conducted using elbow specimens with local wall thinning. Local wall thinning was machined on the inside of the elbow in order to simulate metal loss from erosion corrosion. The local wall thinning was located in three different areas known as the extrados, crown and intrados. The elbow specimens were subjected to cyclic in-plane bending under displacement control without internal pressure. In addition, three-dimensional elastic-plastic analyses were also carried out using the finite element method. As a result, the crack penetration area and the crack growth direction were successfully predicted by the analyses. The fatigue lives estimated by the analyses were close to those obtained by the experiments.