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This paper presents a high‐precision, successive approximation register (SAR) analog‐to‐digital converter (ADC) with resistive analog front‐end for low‐voltage and wide input range applications. To suppress the serious nonlinearity brought by the voltage coefficients of analog front‐end without deteriorating differential nonlinearity performance, a mixed‐signal calibration scheme based on piecewise‐linear method with calibration digital‐to‐analog converter is proposed. A compensation current is designed to sink or source from the reference to keep it independent of input signal, which greatly improves the linearity performance. Fabricated in a 0.5‐μm CMOS process, the proposed ADC achieves 88‐dB signal‐to‐noise‐and‐distortion ratio and 103‐dB spurious free dynamic range with 5‐V supply voltage and 2.5‐V reference voltage, and the total power consumption is 37.5 mW.

This study investigates the effects of soybean lecithin (SL) on the growth, fatty acid composition, lipid metabolism, and gonadal development of rice field eels. Fourteen-month-old eels were fed either fish oil diets or varying levels of dietary soybean lecithin (0%, 1.4%, and 2.8%) for 10 weeks. Dietary SL had no significant impact on growth, whereas 1.4% SL led to a significant decrease in moisture content and an increase in crude protein content in eels. The content of both saturated and polyunsaturated fatty acids increased in muscles fed the higher SL diet, with a concurrent decline in saturated fatty acids and an increase in polyunsaturated fatty acids detected in the liver. The expression levels of genes related to lipid synthesis, including accαand PPARγ, and genes related to polyunsaturated fatty acid synthesis, such as pla2g4a, fad2and scd, were significantly increased in the liver of eels fed with 1.4% SL diet. SL supplementation enhances lipid transport and antioxidant capacity in the liver, reduces fat deposition, and protects the liver from damage. Hepatosomatic index of fish in the SL1.4% and SL2.8% groups decreased. Supplementation of the diet with 1.4% SL led to a significant decrease in the content of saturated fatty acids and an increase in the content of polyunsaturated fatty acids in the gonads, with a significant increase in arachidonic acid levels. The gonadosomatic index also increased with increasing dietary SL content. Rice field eels fed diets containing SL exhibited elevated serum levels of E2, delayed ovary-to-testis transition, and a preference for retaining the female state. In conclusion, dietary supplementation with SL increased the proportion of highly unsaturated fatty acids in the tissues, enhanced lipid metabolism in the liver, and improved antioxidant capacity. Furthermore, SL supplementation has been demonstrated to promote ovarian development and delay sex reversal in rice field eels.

10-week dietary arachidonic acid (ARA) feeding trials were conducted in 14-month-old swamp eel (Monopterus albus) to evaluate the effects on growth performance, gonadal development, tissue fatty acid profile, and gene expression related to lipid metabolism. The results showed that swamp eels fed diets supplemented with 1.4% or 2.8% ARA had a significantly higher weight gain rate (WGR) and specific growth rate (SGR) than those fed the control diet. Dietary supplementation with ARA improved oocyte development and maturation. Higher gonadosomatic index (GSI) was detected in 1.4% and 2.8% ARA groups. ARA supplementation delayed sexual reversal in females. The ARA content in the muscle, liver and gonads increased with increasing dietary ARA concentration; however, ARA supplementation significantly reduced the transcriptional expression of lipid metabolism-related genes in the gonads, such as fad2, pla2g4a, and elovl5. Serum alanine aminotransferase (ALT) levels in the ARA 1.4% group were significantly lower than those in the control and ARA 2.8% groups. Total cholesterol (T-CHO) and triglyceride (TG) levels were significantly lower in the 1.4% and 2.8% ARA groups than in the control group. Catalase (CAT) and high-density lipoprotein cholesterol (HDL-C) increased with dietary ARA concentrations. This study found that dietary ARA is important for improving growth, Ovarian development, and antioxidant capacity in swamp eels.