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Biomedical subjects

S T Yu

Publications and source records attributed to S T Yu.

9 recordsLinked to original sources
PubMed2006

A batch study on the bio-fixation of carbon dioxide in the absorbed solution from a chemical wet scrubber by hot spring and marine algae.

Carbon dioxide mass transfer is a key factor in cultivating micro-algae except for the light limitation of photosynthesis. It is a novel idea to enhance mass transfer with the cyclic procedure of absorbing CO(2) with a high performance alkaline abosorber such as a packed tower and regenerating the alkaline solution with algal photosynthesis. Hence, the algae with high affinity for alkaline condition must be purified. In this study, a hot spring alga (HSA) was purified from an alkaline hot spring (pH 9.3, 62 degrees C) in Taiwan and grows well over pH 11.5 and 50 degrees C. For performance of HSA, CO(2) removal efficiencies in the packed tower increase about 5-fold in a suitable growth condition compared to that without adding any potassium hydroxide. But ammonia solution was not a good choice for this system with regard to carbon dioxide removal efficiency because of its toxicity on HSA. In addition, HSA also exhibits a high growth rate under the controlled pHs from 7 to 11. Besides, a well mass balance of carbon and nitrogen made sure that less other byproducts formed in the procedure of carboxylation. For analysis of some metals in HSA, such as Mg, Mn, Fe, Zn, related to the photosynthesis increased by a rising cultivated pH and revealed that those metals might be accumulated under alkaline conditions but the growth rate was still limited by the ratio of bicarbonate (useful carbon source) and carbonate. Meanwhile, Nannochlopsis oculta (NAO) was also tested under different additional carbon sources. The results revealed that solutions of sodium/potassium carbonate are better carbon sources than ammonia carbonate/bicarbonate for the growth of NAO. However, pH 9.6 of growth limitation based on sodium was lower than one of HSA. The integrated system is, therefore, more feasible to treat CO(2) in the flue gases using the algae with higher alkaline affinity such as HSA in small volume bioreactors.

Air Pollutants↗
PubMed1993

Prevalence of human papillomaviruses 16 and 18 in transitional cell carcinoma of bladder.

It has been speculated that human papillomaviruses (HPV) might be a causative agent of transitional cell carcinoma of the bladder. With the polymerase chain reaction technic, fresh specimens of 53 transitional cell carcinomas of the bladder were examined, and bladder epithelium from 12 patients with hyperplasia of prostate and peripheral blood lymphocytes of 8 normal individuals served as controls. The primers set for HPV-16 and 18 were selected from E6/E7 regions of open reading frames. HPV-16 was positive in 52.8% of the specimens examined, whereas HPV-18 positive in only 3.7%. No controls showed either HPV-16 or 18. Reports on the role of HPVs in carcinogenesis of bladder are scanty and yet there exist conspicuous discrepancies among them. There is a diversity of opinions on the contamination and variation of technical procedures. More work should be done before the relationship between HPV-16 and development of bladder carcinoma can be clarified.

Base Sequence↗
PubMed1993

[The bioavailability of transdermal therapeutic system of timolol].

A matrix-type transdermal therapeutic system of timolol (TTS-timolol) was well prepared. The patch consisted of backing membrane layer, timolol reservoir layer, pressure sensitive adhesive layer and protective layer. A sensitive and reliable HPLC-UV method for the determination of plasma level of timolol in healthy volunteers was developed. Effective therapeutic plasma level of timolol (4 ng/ml) was attained 4 h after application of the timolol patches and was maintained within 32 h while the patch was removed at 24 h. The pharmacokinetic behavior of this transdermal therapeutic system (TTS)-timolol in human showed zero order absorption and well fitted to a one compartment model. The pharmacokinetic parameters are: Tmax = 18.8 h; Cmax = 11.2 ng/ml; AUC = 265.7 ng/ml.h; Vss = 120.0 L; K = 0.084 h-1. In comparison with the results of oral administration of timolol tablets, TTS-timolol possesses some advantages: stable plasma level, long effective time and convenient administration.

Administration, Cutaneous↗
PubMed1991

Effect of endothelin-1 on the vascular smooth muscle cell cycle.

Rabbit vascular smooth muscle cells were cultured in various concentrations of endothelin-1 (ET-1) at 37 degrees C for 24 h. The vascular smooth muscle cell cycle distribution was determined by flow cytometry according to DNA content. In the control group, the mitotically active phase (S + G2 + M phase) of vascular smooth muscle cells was 11.94%. In ET-1-cultured smooth muscle cells, the mitotically active phase was 11.69% at a concentration of 1 pM ET-1, whereas the mitotically active phases were 18.98 and 26.91% at concentrations of 0.1 and 10 nM ET-1, respectively. The findings show that ET-1 significantly increased mitotic activity of cultured vascular smooth muscle cells.

Animals↗
PubMed1989

[Determination of flecainide concentration in blood plasma by HPLC and pharmacokinetic parameters in volunteers].

A high performance liquid chromatographic method (ultraviolet detection) for the determination of flecainide concentration in human plasma was reported. Flurazepam (dalmadorm) was used as the internal standard. A mixture of methanol and deionized water containing ion paired reagent served as the mobile phase. The regression equation of flecainide was: y = 0.0017x + 0.0131, r = 0.9975. The extraction recoveries exceeded 94%, and the coefficients of variation (both within the same day and in different days) were less than 5%. The pharmacokinetic parameters in Chinese volunteers after taking flecainide were: Ka = 0.908h-1, T1/2 = 8.131h, peats time = 3.487h, AUC = 441.8ng.h/ml. The mean plasma concentration of flecainide in cases responded well to this drug was 423.6 +/- 227.4ng/ml.

Adult↗
PubMedDate not supplied

Synthesis of a 10,000 member 1,5-benzodiazepine-2-one library by the directed sorting method.

The solid-phase synthesis of a 10,000 member combinatorial library of 1,5-benzodiazepine-2-one derivatives is reported. The 3-amino-1,5-benzodiazepine-2-one scaffold was prepared in solution, and the benzamide nitrogen was used as a point of attachment to the resin. The 5-aniline and 3-amine were then used as points of diversity. A 10,000 member library was synthesized using the Irori directed sorting system, and after analysis of a representative sample from the library, the Irori system was used to remove the compounds of lower purity.

Amines↗