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Twenty-four 21-d-old Arbor Acres (AA) broilers with similar BW were randomly assigned into 4 groups to investigate the effects of stress on the absorption of glucose in the intestine of broilers and its mechanisms. In this study, dexamethasone (DEX), an analog to glucocorticoid secreted when animals suffer from stress, was chosen to simulate the effects of glucocorticoid. Broilers were injected subcutaneously with 0, 0.1, 1, or 5 mg of DEX/kg of BW into the abdomen for 7 d. To explain the nonspecific regulation of glucocorticoid on glucose transport of the jejunum in broilers, the effects of DEX on the jejunum mucosa morphology and disaccharidase activities in broilers were investigated. The results showed that DEX restrained the growth of broilers, and the extent of restraint increased with the increase of the dose of DEX (P0.05). However, the activities of sucrase and maltase in the jejunum of the broilers injected with DEX were not different from those of the control broilers (P0.05). In addition, DEX increased the crypt depth of jejunum in broilers, and decreased the villus height, absorption area, and villus height/crypt depth ratio significantly (P0.05), whereas DEX had no significant effect on villus width and the thickness of mucosa lamina propria (P0.05). To clarify the specific regulation of glucocorticoid on the glucose transport of jejunum in broilers, the absorption of glucose by jejunum brush border membrane vesicles (BBMV) was investigated, and the expression of Na+-dependent glucose transporter (SGLT1) mRNA was detected by real-time PCR. The results showed that DEX significantly inhibited the glucose absorption of jejunum BBMV (P0.05), and the extent of inhibition depended on the dose of DEX. In addition, DEX decreased the expression of SGLT1 mRNA significantly (P0.05). According to these data, we concluded that DEX restrains the glucose transport of jejunum in broilers through nonspecific and specific regulations.

Glass formation and glass-forming ability (GFA) in the La(100−x)[Al0.412(Cu,Ni)0.588]x (x = 30–44.6 at.%) system were studied in detail, and effectiveness of the phenomenological GFA indicator γ, defined as Tx/(Tg + Tl) (Tx onset crystallization temperature, Tg glass transition temperature and Tl liquidus temperature), is also discussed. Our experimental data indicate that γ is generally reliable in estimating the GFA of the current alloy system. Based on the framework of phase competition and crystallization kinetics, composition effects on GFA and its indicator γ in both simple regular and irregular eutectic systems were further analyzed. It was confirmed that γ is capable of representing the GFA of most alloys in both eutectic systems but might be less accurate in assessing the GFA of the compositions whose decisive competing crystalline phase during cooling is different from that upon devitrification. In the latter cases, the measured Tx value upon devitrification is not sufficient to indicate the crystallization resistance of the real competing phase during cooling.

Criteria for evaluating the glass forming ability of La–Al–(Cu,Ni) alloys, e.g., the extent of the supercooled liquid region ΔTx (ΔTx = Tx − Tg, Tg is glass transition temperature, and Tx is the onset temperature of the first crystallization event), the reduced glass transition temperature Trg (Trg = Tg/Tl, Tl is the liquidus temperature), the apparent activation energy of the first crystallization peak Ep1, and γ ( γ = T x / ( T g + T l ) ) etc., were studied. The criteria were categorized into Tl related and Tl not related ones. The Tl related criteria, such as Trg and γ, etc., generally use the values of Tl measured by DSC (or DTA) heating. They will be depressed to different extent with varying compositions during non-equilibrium cooling, especially for bulk glass forming alloys. This paper suggests to use the solidification temperature Ts instead of Tl.

The effects of intrinsic saturation magnetization σ s on media magnetic properties and recording performance in Co–Cr–(Pt)–Ta alloy films were studied. Correlation between cobalt content and σ s and between σ s and media signal-to-noise ratio (SNR), has been revealed. Additions of Cr and Ta strongly reduce the film saturation magnetization; the addition of Pt makes the reduction of saturation magnetization less pronounced. It is found that higher σ s degrades media SNR. The mechanism for this decrease in SNR is believed to be an increase in the strength of magnetostatic interaction. It is concluded that for very low noise recording media low saturation magnetization alloys are preferred.

We present the application of a self-aligned sidewall gating technique in the fabrication of gated resonant tunneling devices with active mesa areas in the sub-micron regime. This technique should prove useful for the fabrication of variable area, vertical quasi one- and two-dimensional structures. We present current-voltage curves of gated devices at room temperature and liquid nitrogen temperatures for conduction in both directions through the double barrier structure. An analysis demonstrating the vertical uniformity of the gate field around the double barrier structure, a discussion on the possible extension of the technique to low-dimensional structures and the limits of application are presented.