Trace determination of fifteen free amino acids in drinking source water via solid-phase extraction coupled with liquid chromatography tandem mass spectrometry.

Amino acids (AAs) are important nitrogen-containing organics in water, and a large number of reports have proven that they were the precursors of many nitrogen-containing disinfection by-products, some of which have cytotoxicity and carcinogenicity. However, little has been done on their occurrence in drinking source water. Therefore, a trace determination method via solid-phase extraction coupled with ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for 15 free AAs (FAAs) was developed, which was successfully applied for drinking source water samples.

[Study of symbolic element in roasting slag of pyrite by inductively coupled plasma mass spectrometry].

In the present paper, the correlations between sixteen elements from the dry method roasted dust-slag of pyrite and sixteen elements from the soil layer near and far from the store area were studied by ICP-MS. Similar radio and outstanding different radio of the elements between the dust-slag and the soil were studied too. It was discovered that in the pollution soil layer Tl, Cd, Cs, Cu, Zn, Mn, Pb and Ni were easy to be identified and had similar radio with the elements in the dust-slag.

Study on oxidation of pyrite by in situ absorption spectroscopy.

Pyrite is one of the common natural mineral. It is easily oxidized and brings heavy metal contaminations, therefore it is the main source of acidity mine drainage. The study on the dynamics of pyrite is helpful to comprehending the mechanism of its pollution.

[Application of ICP-MS in evaluating element contamination in soils].

The Yunfu pyrite was the second biggest pyrite bed in the world. Plants using industrial ore of the Yunfu pyrite are distributed in many sections across the country. In the present paper, elements V, Cr, Co, Cu, Zn, Mo, Cd, Sb, Rb and Cs in soil profiles in slag disposing area of a sulfuric acid plant using industrial ore of theYunfu pyrite were studied.

[Determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry].

A method for determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry under normal or high temperature and high humidity condition was described. The ways of samples pretreatment, analysis and rapid clearing up bad memory were researched. The results showed: that the effect of instability of mercury can be cushioned under high temperature and high humidity condition by choosing much negative high pressure and control long the fluorescence intensity of standard blank.

Characteristics of basal cell carcinoma amongst Asians in Singapore and a comparison between completely and incompletely excised tumors.

Background: Most published series of basal cell carcinomas (BCCs) are based on Caucasian populations. Very little is known about the characteristics of incompletely excised BCCs in Asians.

Objectives: This study examines the characteristics of BCCs in Asian residents in Singapore, and compares incompletely with completely excised tumors after conventional surgical excision.

A randomized, placebo-controlled trial of thymosin-alpha1 and lymphoblastoid interferon for HBeAg-positive chronic hepatitis B.

Combination therapy between two immunomodulators used for treatment of chronic hepatitis B was explored based on reported therapeutic efficacy of interferon-alpha, and thymosin-alpha1 as monotherapeutic agents to determine if combination therapy was superior to interferon alone. This double-blinded, randomized, placebo-controlled trial compares the addition of thymosin-alpha1, 1.6 microg taken three times per week (combination therapy) or thymosin placebo (monotherapy) to lymphoblastoid interferon (Wellferon), 5 million international units (MIU) taken three times per week, for 24 weeks.

Acute primary angle closure: configuration of the drainage angle in the first year after laser peripheral iridotomy.

Purpose: To evaluate the changes in the configuration of the drainage angle in the first year after acute primary angle closure (APAC).

Design: Prospective observational case series.

Participants: Forty-four Asian subjects with APAC.