2,915 research outputs found
Cytotoxic activity of aminoderivatized cationic chitosan derivatives
No full textChitosan derivatives were prepared by dialkylaminoalkylation and reductive amination followed by quaternization. In this study, the cytotoxic activity of the chitosan derivatives was investigated and a relationship between structure and activity is suggested. The cationic chitosan derivatives elicited dose-dependent inhibitory effects on the proliferation of tumor cell lines. (C) 2002 Elsevier Science Ltd. All rights reserved.This work was supported by the Ministry of Education of Korea
The Electrical, Optical and Structural Characteristics of N-type Microcrystalline Silicon Thin Films Deposited by TCP-CVD
No full textBlue light-emitting polymer/dielectric nanolayer nanocomposites: Impediment of excimer formation and enhancement of photostability
No full textBlue light-emitting polymer/dielectric nanolayer nanocomposites were fabricated by solution intercalation method and the photoluminescence data showed that these nanolayers act as sepaxation layers to isolate polymer chains. Furthermore the dielectric nanolayers whose aspect ratio is about 500, also acted as efficient barriers to oxygen resulting in low keto-type emission and photo-oxidation
Optical and Electrical Properties of Boron Doped Amorphous Silicon-Carbon Thin Films by TCP-CVD
No full textA STEREOSELECTIVE SYNTHETIC ROUTE TO CIS-2,5-DISUBSTITUTED TETRAHYDROFURANS
No full textAn efficient stereocontrolled synthesis of cis-2,5-disubstituted tetrahydrofurans from triethylsilyl ethers of trans-4-phenyl-3-buten-1-ol derivatives 19-24 was developed by using phenylselenyl chloride in the presence of potassium carbonate in acetonitrile
Long-term ultrasonographic features of the Achilles tendon after rupture.
No full textPURPOSE:
To assess the long-term ultrasonographic appearance of rupture of the Achilles tendon.
SUBJECTS AND METHODS:
We examined 70 patients at an average of 63 months (range 10-120 months) after rupture of the Achilles tendon. We assessed the patient's contralateral tendon and also performed ultrasonography on the Achilles tendon of 70 age- and sex-matched controls. We recorded the maximum transverse anteroposterior diameter, the presence of intratendinous alterations, and the presence of intratendinous calcification.
RESULTS:
The average maximum anteroposterior diameter of the ruptured tendon was 11.7 mm (SD = 2.10). The patients' normal tendons measured an average of 5.4 mm (SD = 0.9), and there was an average measure of 4.9 mm (SD = 0.5) (p = 0.0001) in the controls. There was no difference in the maximum anteroposterior diameter of the ruptured tendon depending on the method of treatment (conservative, open repair, percutaneous repair). Seventeen patients exhibited areas of hypoechogenicity in their ruptured tendon, two patients had areas of hypoechogenicity in their unruptured contralateral tendon, and 10 patients had calcification in their ruptured tendon.
CONCLUSION:
The anteroposterior diameter of the ruptured tendon was significantly greater than the nonruptured contralateral. However, when compared with a group of individually age- and sex-matched controls, the patients' contralateral tendons had significantly greater maximum anteroposterior diameter and had a greater prevalence of intratendinous alterations. This difference may represent a background of subclinical tendinopathy that may predispose to rupture
Evaluation of porous ceramic as microbial carrier of biofilter to remove toluene vapor
No full textThree kinds of porous ceramic microbe media are fabricated from fly ash, diatomite and a mixture of fly ash and diatomite powders. Water holding capacity, density, porosity, pore size and distribution, compressive strength and micro-structure of each of the fabricated media are measured and compared. The fly ash and diatomite mixture ceramic is evaluated as the best biofilter medium among the three media because of its high compressive strength. It is selected as an experimental biofilter medium inoculated with thickened activated sludge. The laboratory scale biofilter was operated for 42 days under various experimental conditions varying in inlet toluene concentration and flow rate of contaminated air stream. The experimental result shows that the removal efficiency reaches up to 96.6% after 4 days from the start-up. Nutrient limitation is considered as a major factor limiting biofilter efficiency. Biofilter efficiency decreases substantially at the build-up of backpressure, which is largely due to the accumulation of excess VSS within the media. Periodic backwashing of the biofilter is necessary to remove excess biomass and attain stable long-term high removal efficiency. The bed needs to be backwashed when the overall pressure drop becomes greater than 460.6Pa at space velocity of 100h(-1). A maximum flow rate of 444.858 m(-3)hr(-1) of toluene elimination by the mixture ceramic biofilter, which is higher than the previously reported values. This indicates that the fly ash and diatomite mixture ceramic biofilter can be effectively applied for removing toluene vapor
Author Lili Mendoza discusses intellectual freedom in her work
No full textHear Lili Mendoza describe how intellectual freedom motivates her creative endeavors. Lili Mendoza is a fiction writer, poet, translator and was born in Panama. She is the author of the short story collection Corazón de charol a-go-gó (2009). Her stories and poetry have been anthologized in Panama, Costa Rica, Spain, Peru, and the U.S., and showcased at literary events in Europe. An active member of the Theater Guild of Ancon, Mendoza also collaborates in musical and dance performances.
Interviewer Brian JK Mille
On an error term related to the Jordan totient function Jk(n)
No full textAbstractWe investigate the error terms Ek(x)=∑n⩽xJk(n)−xk+1(k+1)ζ(k+1) for k⩾2, where Jk(n) = nkΠp|n(1 − 1pk) for k ≥ 1. For k ≥ 2, we prove ∑n⩽xEk(n)∼xk+12(k+1)ζ(k+1). Also, lim infn→∞Ek(x)xk⩽Dζ(k+1), where D = .7159 when k = 2, .6063 when k ≥ 3. On the other hand, even though lim infn→∞Ek(x)xk⩽−12ζ(k+1), Ek(n) > 0 for integers n sufficiently large
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