Acid-stable amperometric soybean peroxidase biosensor based on a self-gelatinizable grafting copolymer of polyvinyl alcohol and 4-vinylpyridine

A peroxidase was extracted from Chinese soybean seed coat, and its thermostability and acid-stability were characterized. This peroxidase was immobilized into a self-gelatinizable grafting copolymer of polyvinyl alcohol with 4-vinylpyridine(PVA-g-PVP) to construct an acid-stable hydrogen peroxide biosensor. The effect of pH was studied for optimum analytical performances by amperometric and spectro-photometric methods, also the K-m(app) and the stability of the soybean peroxidase-based biosensor are discussed. At pH 3.0, the soybean peroxidase maintained its bioactivity and the enzyme electrode had a linear range from 0.01 to 6.2 mM with a detection limit of 1.0 x 10(-7) M. In addition, the main characteristics of different hydrogen peroxide sensors were compared.

Studies of non-covalent protein complexes by MALDI methods

Several specific non-covalent protein complexes were successfully observed by matrix assisted desorption ionization mass spectrometry(MALDI MS). The methods described in this paper include the matrixes use of sinapinic acid(SA) and 6-aza-2-thiothymine (ATT) in neutral pH solution, as well as the improvement of two-layer sample preparation method to achieve a high sensitivity detection of stable non-covalent complexes, Myoglobin-heme complex was found simultaneously with the sinapinic acid matrix in the various pH solution(pH=2 or pH=5), The RNase S complex showed a striking intensity at the first shot, which was decreased with more laser shots. Most importantly, the observation of specific non-covalent complex in the brome mosaic virus(BMV) coat proteins would open up a new possibility to investigate the assembly and disassembly of viral capsids.

Artificial neural network applied to diagnosis of lung cancer

Artificial neural network(ANN) approach was applied to classification of normal persons and lung cancer patients based on the metal content of hair and serum samples obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) for the two groups. This method was verified with independent prediction samples and can be used as an aiding means of the diagnosis of lung cancer. The case of predictive classification with one element missing in the prediction samples was studied in details, The significance of elements in hair and serum samples for classification prediction was also investigated.

Insulin-like growth factor-binding protein-3 plays an important role in regulating pharyngeal skeleton and inner ear formation and differentiation

Insulin-like growth factor-binding protein (IGFBP)-3 is the major insulin-like growth factor (IGF) carrier protein in the bloodstream. IGFBP-3 prolongs the half-life of circulating IGFs and prevents their potential hypo-glycemic effect. IGFBP-3 is also expressed in many peripheral tissues in fetal and adult stages. In vitro, IGFBP-3 can inhibit or potentiate IGF actions and even possesses IGF-independent activities, suggesting that local IGFBP-3 may also have paracrine/autocrine function(s). The in vivo function of IGFBP-3, however, is unclear. In this study, we elucidate the developmental role of IGFBP-3 using the zebrafish model. IGFBP-3 mRNA expression is first detected in the migrating cranial neural crest cells and subsequently in pharyngeal arches in zebrafish embryos. IGFBP-3 mRNA is also persistently expressed in the developing inner ears. To determine the role of IGFBP-3 in these tissues, we ablated the IGFBP-3 gene product using morpholino-modified antisense oligonucleotides (MOs). The IGFBP-3 knocked down embryos had delayed pharyngeal skeleton morphogenesis and greatly reduced pharyngeal cartilage differentiation. Knockdown of IGFBP-3 also significantly decreased inner ear size and disrupted hair cell differentiation and semicircular canal formation. Furthermore, reintroduction of a MO-resistant form of IGFBP-3 "rescued" the MO-induced defects. These findings suggest that IGFBP-3 plays an important role in regulating pharyngeal cartilage and inner car development and growth in zebrafish.

Corrosion resistance of steel with hot-dipped galvanized zinc and zinc alloy coatings in seawater

Hot-dipped galvanized zinc and zinc alloy coatings were used as the hot-dipped low alloy zinc coatings (aluminum content less than protective metallic coatings for steel structures in seawater in Chi- or equal to 10 wt%) is equal to or even lower than that of the pure na. Corrosion of the two coatings immersed in sea water in Qingdao zinc sheet, while the performance of the hot-dipped high alloy zinc and Xiamen for 6 years were introduced and analyzed, which pro-coatings is higher than that of the pure zinc sheet. The hot-dipped vides a basis for further development and applications of these coat- high alloy zinc coatings can be further developed for optimal tings in China. Tests proved that the anti-corrosion performance of formance in the future.

Effect of urea multinutritional molasses block supplementation on liveweight change of yak calves and productive and reproductive performances of yak cows

Using three different types of yaks, 30 head of 1-yr-old calves (liveweight 60.7 +/- 6.3 kg), 30 head of 2-yr-old calves (97.7 +/- 10.2 kg) and 30 head of yak cows (160.2 +/- 15.1 kg) were randomly selected from the same yak herds. Each type of yak herd was divided into control (C) and trial (T) groups using a completely randomized design, with 10 and 20 animals in the C and T groups, respectively. The animals in the C group were grazed on natural rangeland, and the animals in the T group were supplemented with urea multinutritional molasses blocks (UMMB), together with grazing on natural rangeland from January to May of 1998. The objective was to determine the effect of UMMB on productive performance of yak calves and yak cows in the cold season. Live weight loss of 1-yr-old calves, 2-yr-old calves and yak cows was reduced by 1.2, 8.3 and 7.9 kg after UMMB supplementation (P < 0.01). The 1-yr-old calves gained the most in the first month of supplementation, but the 2-yr-old calves and yak cows gained the most both in the first and last supplementation months. Daily milk yield of yak cows increased by 0.21 kg d(-1) when the lactating animals were supplemented with UMMB (P < 0.01), although there was no effect (P < 0.01) of UMMB supplementation on hair and downy hair production. Supplementation with UMMB also improved reproductive performance of yak cows, with 8.8 and 30.9% increments in pregnancy rate and newborn weight, respectively. We conclude that the benefit of UMMB supplementation the 1-yr-old calves was not economical, with only 0.3:1 output to input ratio, but supplementation of the 2-yr-old calves and yak cows may be economical, with 1.8:1 and 1.4:1 output to input ratios, respectively.