Pathogenesis of hyponatremia following subarachnoid hemorrhage due to ruptured cerebral aneurysm

BACKGROUND: Hyponatremia following subarachnoid hemorrhage (SAH) occurs due to the inappropriate secretion of antidiuretic hormone (SIADH). However, this condition is also sometimes associated with certain dehydration states. METHODS: To clarify the pathogenesis, daily values of urine volume, water balance, and sodium balance (Na Bal) were correlated with plasma levels of atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), and plasma renin activity (PRA) in 31 cases of SAH. RESULTS: Na Bal was markedly negative on days 2 and 3. Cumulative Na Bal showed continuous negative values until day 10 following SAH. ANP values showed a consistent elevation, while ADH showed only an initial surge. PRA, as the gross indicator of circulatory volume, showed a lack of suppression, indicating no increase in the circulatory volume. CONCLUSION: Hyponatremia following SAH therefore appears to be the result of increased natriuresis, due to the inappropriate elevation of ANP rather than SIADH. In this situation, water restriction should not be recommended, since the circulatory volume is decreased.     

Dependence of process characteristics on atomic-step density in catalyst-referred etching of 4H-SiC(0001) surface

Catalyst-referred etching (CARE) is a novel abrasive-free planarization method. CARE-processed 4H-SiC(0001) surfaces are extremely flat and undamaged over the whole wafer. They consist of single-bilayer-height atomic steps and atomically flat terraces. This suggests that the etching properties depend principally on the atomic-step density of the substrate surface. We used on-axis and 8 degrees off-axis substrates to investigate the processing characteristics that affect the atomic-step density of these substrates. We found a strong correlation between the removal rate and the atomic-step density of the two substrates. For the on-axis substrate, the removal rate increased with increasing surface roughness, which increases with an increasing atomic-step density. The removal rate ratio is approximately the same as the atomic-step density ratio of the two substrates.     

Efficient wet etching of GaN (0001) substrate with subsurface damage layer

Photoenhanced chemical (PEC) etching is applicable for processing an n-GaN (0001) surface rapidly. In this process, the surface oxidation is enhanced by photo-generated holes and the resulting oxide can dissolve into solutions. In current work, we conduct bias-assisted PEC etching in a KOH solution with a positively biased wafer, to remove the crystallographically highly damaged layer. The employed substrate was mechanically polished with diamond slurry of sub-micrometer particle size. Without the positive bias, the rate of PEC etching was quite low because the photogenerated holes were quickly depleted by the recombination process at the crystallographic defects and they could not contribute to the oxidation. On the other hand, in the case where the bias was applied, the photogenerated holes and electrons are separated forcibly in the band-bended surface, which effectively contributed to surface oxidation. As a result, a high removal rate was realized even on the damaged surface.     

Natural tubule clay template synthesis of silver nanorods for antibacterial composite coating

Halloysite is naturally available clay mineral with hollow cylindrical geometry and it is available in thousands of tons. Silver nanorods were synthesized inside the lumen of the halloysite by thermal decomposition of the silver acetate, which was loaded into halloysite from an aqueous solution by vacuum cycling. Images of individual ca. 15 nm diameter silver nanorods and nanoparticles were observed with TEM. The presence of silver inside the tubes was also verified with STEM-EDX elemental mapping. Nanorods had crystalline nature with [111] axis oriented ~68° from the halloysite tubule main axis. The composite of silver nanorods encased in clay tubes with the polymer paint was prepared, and the coating antimicrobial activity combined with tensile strength increase was demonstrated. Coating containing up 5% silver loaded halloysite did not change color after light exposure contrary to the sample prepared with loading with unshelled silver nanoparticles. Halloysite tube templates have a potential for scalable manufacturing of ceramic encapsulated metal nanorods for composite materials.     

Production of recombinant human lysosomal acid lipase in Schizosaccharomyces pombe: development of a fed-batch fermentation and purification process

A fed-batch fermentation process has been developed to enable the production of large quantities of recombinant human lysosomal acid lipase (hLAL; EC 3.1.1.13), in Schizosaccharomyces pombe, for preclinical studies as a potential enzyme therapy drug. Recombinant S. pombe, clone ASP397-21, expressed enzymatically active hLAL in the secreted form. A feedback fed-batch system was used to determine the optimal feed rate of a 50% glucose solution used as the carbon source. The feed rate of the glucose solution was calculated by a computer-aided system according to the equation; F=q(sf)(VX)/S(in) (q(sf), specific substrate feed rate [gram substrate/gram dry cell weight/h]; V, volume of culture broth [l]; X, cell density [gram dry cell weight/l]; S(in), concentration of growth limiting substrate in feed solution [gram substrate/gram feed solution]). At the time of the initial consumption of glucose in the batch-phase culture, the nutrient supply was automatically initiated by means of monitoring the respiratory quotient change. The obtained profile of the feed rate was applied to the feed forward control fermentation. Finally, the cells were grown up to >50 g dry cell weight/l, and the hLAL expression level was approximately 16,000 U/l. Expressed hLAL protein was purified in a two-step process by hydrophobic interaction and anion exchange chromatographies. Purified recombinant hLAL exhibited a 90-150 kDa broad band upon SDS-PAGE with specific activity of about 300 U/mg. After endoglycosidase H treatment, the band converged to 45 kDa, equal to the calculated molecular weight, suggesting that hLAL produced in S. pombe was hyper-glycosylated. N-terminal analysis of de-glycosylated hLAL revealed that the signal sequence of hLAL was correctly processed in S. pombe.     

0.25?μm 1.2?MHz BOOST-PFM-CONTINUOUS triple mode LED driver integrated in analog front end IC for portable application

This paper proposes a triple mode LED driver integrated with 16bit level sensitive analog front end by 0.25???m CMOS process for portable application. The LED driver needs to regulate single LED current with 0.9?C3.6 V_input voltage to support several types of battery. The output range is 2.5?C4?V which requires voltage step-up and step-down. A step-up/step-down converter can do this with a lot complexity, more components, lower efficiency and requirement of high voltage switches which adds extra manufacture cost. Our proposed topology avoids complicated step-up/step-down topology. It has triple modes: Boost PWM mode, PFM mode, LDO mode to cover different input voltage range. The mode control is implemented by simple circuit and gives smooth mode transition and very stable LED current. The simple topology makes it possible to use two stack 3?V IO devices as internal power switch to tolerate max to 5.7?V. By careful design and layout, LED switching activity only degrades the 16bit level analog front end SNR by 1?dB.     

Photoreduction of Carbondioxide on Surface Functionalized Nanoporous Catalysts

Nanoporous photocatalysts have been designed to exhibit unique photocatalytic activities through framework substitution of titanium species or surface immobilization of rhenium complex onto mesoporous silica. This article summarizes recent work on the synthesis, characterization and photocatalytic activities of the designed porous photocatalysts performed by the present authors. Various spectroscopic investigations revealed that the photo-excited states of these catalysts play a vital role in the photocatalytic reactions and their photocatalytic reactivities are strongly dependent on structures of active sites, which are confined and immobilized in the restricted framework structure of the mesoporous silica. Highly dispersed titanium oxide species incorporated in the framework of mesoporous silica exhibited high and unique photocatalytic reactivity for the reduction of CO₂ with H₂O to produce CH₄ and CH₃OH under UV irradiation, its reactivity being much higher than bulk TiO₂. The cationic rhenium(I) complex was encapsulated into a mesoporous AlMCM-41 material by ion-exchange method, yielding a visible light photocatalyst to be active for photocatalytic reduction of CO₂.     

Fatty acids in must prepared from 11 grapes grown in Japan: Comparison with wine and effect on fatty acid ethyl ester formation

FA components of 11 mustsmade from grape cultivars grown for making red wine in various regions of Japan and of wines made from the musts were compared to elucidate variety-dependent characteristics and to clarify their effect on FA ethyl ester (FAEE) formation in wine. Sixteen FA with carbon chain lengths from 12 to 26 were detected in all musts, with palmitic, linoleic, and linolenic acids generally predominating. Higher levels of linoleic acid were found in musts from a cold region (Hokkaido), and higher levels of oleic acid occurred in musts from a warm region (Honshu). Moreover, the unsaturation indexes (1.31–1.56) of five grape musts from the cold region showed significant differences among varieties, corresponding to the grapevines’ degree of cryotolerance. The FA levels (610–6,610 nmol/100 mL) of all wines were extremely low (1.2–12.8%) compared with those of must, but the FA compositions were similar to those of must. Additionally, significant amounts of FAEE, possibly derived from yeast activity, were found in wines by using a solid-phase extraction method. The amounts of FAEE in wine significantly differed among samples (245–904 nmol/100 mL) and were inversely correlated with the percentage of linoleic acid in musts (R=−0.883). Thus, higher linoleic acid levels in must may be related to lower FAEE formation by yeast.     

Improvements in time resolution and signal-to-noise ratio in a compact pico-second pulse radiolysis system

A compact pico-second pulse radiolysis system has been developing at Waseda University for studying primary processes in radiation chemistry. The system is composed of a photo-injector system and a pico-second all-solid-state laser system. An infrared (IR) and an ultraviolet (UV) laser pulses are obtained from mode-locked Nd:YLF laser system and used for generation of the white light continuum as a probe light and the irradiation to the Cu cathode of a photo-cathode RF-gun, respectively. To improve signal-to-noise (S/N) ratio and time resolution of this pulse radiolysis system, we optimized both probe light and pump electron beam. As a result, our pico-second pulse radiolysis system has been enough to study the primary processes of radiation chemistry. The experimental results and the improvements of our system are described in this paper.