Note: direct measurement of the point-to-point resolution for microns-thick specimens in the ultrahigh-voltage electron microscope

We report on a direct measurement method and results of the point-to-point resolution for microns-thick amorphous specimens in the ultrahigh-voltage electron microscope (ultra-HVEM). We first obtain the ultra-HVEM images of nanometer gold particles with different sizes on the top surfaces of the thick epoxy-resin specimens. Based on the Rayleigh criterion, the point-to-point resolution is then determined as the minimum distance between centers of two resolvable tangent gold particles. Some values of resolution are accordingly acquired for the specimens with different thicknesses at the accelerating voltage of 2 MV, for example, 18.5 nm and 28.4 nm for the 5 μm and 8 μm thick epoxy-resin specimens, respectively. The presented method and results provide a reliable and useful approach to quantifying and comparing the achievable spatial resolution for the thick specimens imaged in the mode of transmission electron including the scanning transmission electron microscope.     

Flow impact of an air conditioner to portable air cleaning

In order to reduce indoor pollutant exposure, people become increasingly interested in portable air cleaning devices, which can be positioned with flexibility. Such purification devices usually discharge cleaned air with strong momentum, which can interrupt indoor airflow created by air-conditioning units. If a well-organized air circulation to a portable air cleaner is not achieved, indoor air purification cannot be fully ensured. This study has used both measurement and computational fluid dynamics (CFD) modeling to investigate the flow interaction between an air conditioner and a portable air cleaner to purify indoor gaseous pollutants. A workshop environment conditioned by an air conditioner and cleaned by a portable air cleaner was mimicked in an environmental chamber to obtain data for validation of a CFD program. Then CFD was applied to evaluate factors that may affect air purification including: positioning of the air conditioner and air cleaner, air conditioner diffuser types, air-conditioning cooling or heating running mode, and location of pollutant sources. The study finds the simulation results are in good agreement with the corresponding experimental data. The positioning coordination of an air conditioner and an air cleaner, and selection of air conditioner diffuser types shall assure a good air circulation cycle to the air cleaner to improve air purification efficacy. In addition to the cleaner effectiveness, it is also recommended to evaluate an air cleaning device in terms of the absolute pollutant concentration, if the portable air cleaner is under the interaction of an air conditioner and the local performance data are interested.     

PET fiber fabrics modified with bioactive titanium oxide for bone substitutes

A rectangular specimen of polyethylene terephthalate (PET) was soaked in a titania solution composed of titanium isopropoxide, water, ethanol and nitric acid at 25 °C for 1 h. An amorphous titanium oxide was formed uniformly on the surface of PET specimen, but did not form an apatite on its surface in a simulated body fluid (SBF) within 3 d. The PET plate formed with the amorphous titanium oxide was subsequently soaked in water or HCl solutions with different concentrations at 80 °C for different periods of time. The titanium oxide on PET was transformed into nano-sized anatase by the water treatment and into nano-sized brookite by 0.10 M HCl treatment at 80 °C for 8 d. The former did not form the apatite on its surface in SBF within 3 d, whereas the latter formed the apatite uniformly on its surface. Adhesive strength of the titanium oxide and apatite layers to PET plate was increased by pre-treatment of PET with 2 wt% NaOH solution at 40 °C for 2 h. A two-dimensional fabric of PET fibers 24 μm in diameter was subjected to the NaOH pre-treatment at 40 °C, titania solution treatment at 25 °C and subsequent 0.10 M HCl treatment at 80 °C. Thus treated PET fabric formed the apatite uniformly on surfaces of individual fibers constituting the fabric in SBF within 3 d. Two or three dimensional PET fabrics modified with the nano-sized brookite on surfaces of the individual fibers constituting the fabric by the present method are believed to be useful as flexible bone substitutes, since they could be integrated with living bone through the apatite formed on their constituent fibers.     

Glycine antagonism does not block ischemic spontaneous depolarization in the rat

Two enzyme-linked immunoassay (ELISA) systems for rapid screening of Listeria spp. were compared for their use in analysis of spiked foods regulated by the U.S. Food and Drug Administration. The Tecra Listeria kit is a 48 h visual ELISA that detects Listeria spp. through colorimetry. It has been approved for first action by AOAC INTERNATIONAL. The Vitek immunodiagnostic assay system for Listeria (VIDAS LIS) is a fully automated 48 h ELISA that detects Listeria spp. by immunofluorescence. Fifty-two food samples were artificially contaminated with high (11-42 colony-forming units [cfu]/25 g food) and low (2-8 cfu/25 g food) levels of L. monocytogenes and screened by the 2 protocols. Unspiked samples were also assayed as negative controls. Six unspiked samples were found positive for Listeria spp. by both methods: 3 were identified as L. monocytogenes and 3 as L. innocua by official methods. Both ELISA methods detected all spiked samples. One unspiked sample was assayed positive by Tecra and negative by VIDAS LIS. No Listeria spp. were recovered when the sample was tested by the conventional method. No interference due to background fluorescence of food matrixes was observed in the VIDAS LIS method. Results suggest a modified VIDAS LIS preenrichment medium may be used in place of the VIDAS standard medium in the protocol.     

Comparison of amyloid deposition in two lines of transgenic mouse that model familial amyloidotic polyneuropathy, type I

Aortic disease frequently requires extended and multiple resections. Occasionally, resection of the entire aorta may be indicated. At our Institution, from 1982 to 1994, 34 patients were operated upon for extended and total simultaneous aortic replacement. In seven patients, the aorta was replaced from valve to bifurcation; in 27, the aortic valve was included. Operations were performed with circulatory arrest under profound hypothermia. As the first step, the aortic valve and ascending aorta are replaced and the coronary arteries are reconnected, following which the aortic arch is reconstructed. Meanwhile, a second surgical team proceeds to open the thoracoabdominal aorta and tie up the intercostal orifices. If circulatory arrest is likely to exceed 60 minutes, the aortic graft is clamped and upper body perfusion (1000 cc/min) is begun. Finally, the thoracoabdominal aorta is fully replaced. Cardiopulmonary bypass (CPB) with rewarming is resumed only after the operation has been completed. Thirty-four patients survived operation; five died within 1 month for an overall mortality of 14.7%. No mortality occurred in the most recent nine operations. No permanent spinal neurological deficits occurred. Total simultaneous aortic replacement for treatment of extended aortic disease may be reasonable using our approach.     

Size distribution measurement and separation of ethanol cluster ion beams

The distributions of the number of molecules per cluster (cluster size) of ethanol cluster ion beams were measured by the time-of-flight method. The cluster sizes at the peak and minimum tail (minimum size) of the distribution increased with increase of the retarding voltage. A difference appeared between the measured minimum size and the calculated values using a formula based on the early measurements on the velocity distributions of gas clusters.     

Fluid resuscitation and systemic complications in crush syndrome: 14 Hanshin-Awaji earthquake patients

BACKGROUND: Crush syndrome is a form of traumatic rhabdomyolysis characterized by systemic involvement, in which acute renal failure is potentially life-threatening. METHODS: Clinical and laboratory data of 14 crush-syndrome patients transferred to a tertiary emergency department after the Hanshin-Awaji earthquake were analyzed. The patients were buried under collapsed houses for the average of 6.7 +/- 5.7 (SD) hours (range, 1 to 24 hours). They were referred to us 6 to 250 hours after the earthquake. RESULTS: Of those who arrived at our institution within 40 hours, 25% (two of eight) developed renal failure, whereas all six patients who arrived after 40 hours developed renal failure. Peak serum creatine kinase ranged from 6,677 to 134,200 U/L (51,674 +/- 41,776). Renal failure was highly associated with massive muscle damage (serum creatine kinase above 25,000 U/L) and insufficient initial fluid resuscitation (below 10,000 mL/2 days). CONCLUSIONS: Prompt and adequate, if not massive, fluid resuscitation is the key to preventing renal failure after such injury.     

Association of an acute reduction in lipoprotein(a) with coronary artery restenosis after percutaneous transluminal coronary angioplasty

BACKGROUND: Lipoprotein(a) [Lp(a)], which structurally resembles-tissue-type plasminogen, is reported to be associated with coronary atherosclerosis. We examined whether the acute change in Lp(a) by percutaneous transluminal coronary angioplasty (PTCA) is related to restenosis after PTCA. METHODS AND RESULTS: We measured serum Lp(a) and other lipid parameters (triglycerides and total, LDL, and HDL cholesterol) before and 1 day after PTCA in 143 procedures and 3 days after and 4 months after PTCA in 62 procedures. Quantitative coronary angiography was performed, and restenosis was defined according to three criteria: (1) clinical recurrence of ischemic symptoms, (2) a final stenosis > 50%, and (3) an absolute decrease in minimal lumen diameter > 1/2 of the acute gain in the dilated segment. Restenosis was recognized in 25.9%, 35.7%, and 38.5% of the cases 4 months after PTCA for each criterion, respectively. Although triglyceride and LDL, HDL, and total cholesterol levels were similar in the restenosis and no-restenosis groups before PTCA, Lp(a) was significantly higher in the restenosis group. We found a significant reduction in Lp(a) in the restenosis but not the no-restenosis group 1 day after PTCA. At 3 days after and 4 months after PTCA, Lp(a) was similar in the two groups. A multivariate-analysis revealed that the absolute change in Lp(a) (before versus 1 day after PTCA) to be the sole significant predictor of restenosis among the clinical, angiographic, and plasma lipid parameters examined. CONCLUSIONS: Lp(a) levels were significantly higher in the restenosis group, and they fell significantly after PTCA in the restenosis group.