大荔县铁镰山区农业集雨水窖建造技术及应用

水资源是制约铁镰山区农业生产的主要因素。本文对铁镰山区集雨水窖工程建设技术、运行管理及推广应用等进行了论述。     

New angiotensin-converting enzyme inhibitory peptide from Coix prolamin and its influence on the gene expression of renin-angiotensin system in vein endothelial cells

Coix seed, which is a traditional Chinese medicine, has been used to treat hypertension for thousands of years. It has been shown that Coix prolamin peptides display high levels of angiotensin I converting enzyme (ACE) inhibitory activity. Hence, we purified the ACE inhibitory peptides from Coix prolamin hydrolysates and evaluated the influence of the most potent peptide on the renin-angiotensin system (RAS) genes expression in human umbilical vein endothelial cells (HUVECs). In this study, Coix prolamin peptides were sequentially separated by ultrafiltration, ion exchange chromatography, gel filtration chromatography and RP-HPLC, while the peptide structure was analyzed by mass spectrometry. Next, in silico proteolysis, pharmacophore and molecular docking were further applied to screen and optimize the structure of peptides. Finally, a novel ACE inhibitory peptide VDMF was obtained, in which its influence on the gene expression of RAS signaling pathway in AngⅡ-injury HUVECs was evaluated by quantitative real-time PCR. VDMF significantly down-regulated ACE, AngII type 1 receptor (AT1R) and ACE2 mRNA expression in comparation with model group, while up-regulating Mas gene expression. Hence, we obtained a novel antihypertensive candidate that was derived from the Coix peptides, which could involve a multi-modulation mechanism that regulates blood pressure.     

沙棘属植物资源概况及其培育技术研究进展

沙棘属植物具有很强的抗逆性和生态适应性,被广泛地应用到水土保持和生态建设事业中。在此分析了沙棘属植物资源现状,总结了我国近年来沙棘属植物的良种引进、繁殖和栽培技术等方面的研究进展,指出了沙棘属植物资源调查和培育实践中需要重点解决的问题,为今后我国沙棘属植物研究提供方向。     

江西地方鸡品种资源的屠宰性能测定研究

对江西省9个地方鸡品种资源的屠宰性能进行了测定。结果表明:江西地方鸡品种资源具有良好的肉用性能,具有广阔的开发利用前景。     

不同西兰花品种与硒肥浓度对硒富集的影响

为了研究不同西兰花品种、硒肥浓度对硒富集的影响,对硒富集量较高的西兰花品种进行了筛选,并在不同西兰花品种、不同硒肥浓度条件下,测定了不同处理的硒元素含量。结果表明:绿天使2号品种较其他品种具有优质、高产、硒元素含量高的特点,应用富硒叶力肥较不施肥的品种硒元素含量高,667 m~2喷施浓度以0.140%最佳,喷施硒肥后产量、硒元素含量较高。     

Characterization and bioactivities of young rice protein hydrolysates

Immature rice was reported to contain higher quantities of bioactive compounds than mature rice. Young rice protein is easy to digest and has hypoallergenic potential, with protein content of 7.2–11.5% compared to rice bran at 9.8%. Few studies have reported on bioactivities and characterization of young rice proteins and their hydrolysates. Bioactivities of native protein and protein hydrolysates of two rice varieties (white rice and colored rice) were characterized and investigated for four development stages (flowery, milky, dough, and mature). Degree of hydrolysis of young rice protein was considerably higher than at the mature stage. Highest DPPH and iron chelating activity were found in alcalase® protein hydrolysate during the flowery-to-milky stage. Iron chelating activity was constant in all development stages because of the low polar amino acid content in rice. The ACE activity of alcalase® protein hydrolysate was higher than native protein at the same development stage, as observed in the milky and dough stages. Inhibitory activity of young rice hydrolysate HepG2 cells was concentration-dependent and not correlated with protein molecular size.     

Analysis of sinking death using video images of the swimming performance of Pacific Bluefin tuna (Thunnus orientalis) larvae

In this study, we aimed to clarify the mechanism of sinking death during the larval stage of Pacific Bluefin tuna Thunnus orientalis by investigating the effects of swimming performance on sinking death, using a behavioral approach. Swimming performance was examined 3–9 days after hatching (DAH) under day and night light conditions in cuboid experimental tanks. Swimming behavior variables such as swimming speed and swimming angle were measured under both light conditions. Larvae in the daytime experiment and larvae with inflated swim bladders at night were distributed on the surface layer of the water column. In contrast, larvae with uninflated swim bladders at night were frequently observed swimming vertically or sinking to the bottom of the tank. Larvae with inflated swim bladders at night were always distributed beneath the surface until the next morning (survival rates were 100 %). However, larvae with uninflated swim bladders at night swam upward repeatedly and later sank to the bottom of the tank (survival rates were 60 % and 38 % at 5 and 9 DAH, respectively). Larvae with uninflated swim bladders were not always able to maintain their swimming depth by swimming until the next morning. Additionally, their swimming speed and vertical swimming frequency (ratio) depended on the illumination and swim bladder conditions. Our findings show that larvae with uninflated swim bladders at night were associated with a higher risk of sinking death. The swimming energy capacity of Pacific Bluefin tuna larvae, which indicates the total amount of the energy that enables individuals to swim throughout the night without feeding, was found to be linked to sinking death.     

Development of a reverse-transcription loop-mediated isothermal amplification assay to detect avian influenza viruses in clinical specimens

In recent years, the avian influenza has brought not only serious economic loss to the poultry industry in China but also a serious threat to human health because of the avian influenza virus(AIV) gene recombination and reassortment. Until now, traditional RT-PCR, fluorescence RT-PCR and virus isolation identification have been developed and utilized to detect AIV, but these methods require high-level instruments and experimental conditions, not suitable for the rapid detection in field and farms. In order to develop a rapid, sensitive and practical method to detect and identify AIV subtypes, 4 specific primers to the conserved region of AIV M gene were designed and a loop-mediated isothermal amplification(RT-LAMP) method was established. Using this method, the M gene of H1–H16 subtypes of AIV were amplified in 30 min with a water bath and all 16 H subtypes of AIV were able to be visually identified in presence of fluorescein, without cross reaction with other susceptible avian viruses. In addition, the detection limit of the common H1, H5, H7, and H9 AIV subtypes with the RT-LAMP method was 0.1 PFU(plaque-forming unit), which was 10 times more sensitive than that using the routine RT-PCR. Further comparative tests found that the positivity rate of RT-LAMP on detecting clinical samples was 4.18%(14/335) comparing with 3.58%(12/335) from real-time RT-PCR. All these results suggested that the RT-LAMP method can specifically detect and identify AIV with high sensitivity and can be considered as a fast, convenient and practical method for the clinic test and epidemiological investigation of AIV.     

Steam explosion of crop straws improves the characteristics of biochar as a soil amendment

Five crop straws(wheat, rice, maize, oil-rape, and cotton) were first steam-exploded for 2 min at 210°C, 2.5 MPa and then pyrolyzed at 500°C for 2 h. Steam explosion(SE) induced 47–95% and 5–16% reduction of hemicellulose and cellulose, respectively, in the crop straws. The biochars derived from SE-treated feedstocks had a lower specific surface area(SSA) and pore volume, compared to those from pristine feedstocks, with one exception that SE enhanced SSA of oil-rape straw biochar by approximately 16 times. After SE, biochars had significant higher anion exchange capacity(AEC)(6.88–11.44 cmol kg~(–1)) and point of zero net charges(PZNC)(pH 3.61–5.32) values. It can thus be speculated that these biochars may have higher potential for anions adsorption. In addition, oil-rape straw might be suitable to SE pretreatment for preparing biochar as a soil amendment and sorbent as well. Further work is required for testing its application in soil.     

Localization of amino acids in germinated rice grain: Gamma-aminobutyric acid and essential amino acids production approach

Germinated rice is popularly consumed for its high gamma-aminobutyric acid (GABA) and bioactive compounds. Supporting information on how to germinate rice with high GABA content and essential amino acids is lacking. White and colored rough rice were germinated for 0, 24, 48, 72, 96, 120 and 144 h. GABA, GABA substrates and essential amino acids were also investigated using GC-MS and MALDI-MSI. GABA was more concentrated after germination and shifted into the coleoptile. High correlation was recorded between germination time and GABA (0.79–0.83, p ≤ 0.01) and glutamic acid (0.88–0.89, p ≤ 0.01). Highest rates of GABA and glutamic production were observed within 48 h of germination in both rice varieties (26.12 and 34.28 mg/100g) and reached maximum value at 96 h (31.36 and 38.75 mg/100g). Colored rice germination showed higher GABA, GABA substrates and deficient amino acids than white rice. GABA and essential amino acids drastically increased after germination, supporting the consumption of germinated rice as a functional food.