bta-miR-33b对牛前体脂肪细胞体外分化的抑制作用研究

【目的】探究bta-miR-33b对牛前体脂肪细胞分化的作用,并对此过程中潜在的靶基因进行验证。【方法】分离培养秦川牛前体脂肪细胞并进行诱导分化,PCR检测bta-miR-33b在前体脂肪细胞分化过程中的时序表达。对牛前体脂肪细胞体外转染bta-miR-33b的mimic、mimic negative control(mimic NC)、inhibitor、inhibitor negative control(inhibitor NC)进行诱导分化培养,于分化培养的不同时间取样,检测脂肪细胞分化标志基因(过氧化物酶体增殖物激活受体γ(PPARγ)基因、CCAAT/增强子结合蛋白α(C/EBPα)基因、脂肪酸结合蛋白4(FABP4)基因)的mRNA表达量及甘油三酯和脂滴含量。预测bta-miR-33b的靶基因,并通过双荧光素酶报告系统验证靶向关系、Western Blot检测靶蛋白的表达量。【结果】在秦川牛前体脂肪细胞分化过程中,bta-miR-33b的表达量呈下降趋势。在前体脂肪细胞分化过程中,bta-miR-33b mimic可抑制脂肪分化标志基因的表达,降低细胞中甘油三酯和脂滴的含量;bta-miR-33b inhibitor可促进脂肪分化标志基因的表达,提高甘油三酯和脂滴的含量。高迁移率族蛋白A2(High mobility group AT-hook 2,HMGA2)基因、扭曲相关蛋白(Twist family bHLH transcription factor 1,TWIST1)基因是bta-miR-33b的靶基因;脂肪细胞分化过程中,bta-miR-33b能够调控HMGA2和TWIST1蛋白水平的表达。【结论】bta-miR-33b对秦川牛前体脂肪细胞体外分化具有抑制作用;HMGA2和TWIST1是bta-miR-33b的靶基因。

Quantum critical behavior in an antiferromagnetic heavy-fermion Kondo lattice system(Ce(1-x)Lax)2Ir3Ge5

The measurements on temperature dependences of magnetic susceptibility χ（T）, specific heat C（T）, and electrical resistivity ρ（T） were carried out for the antiferromagnetic（AFM）（Ce（1-x）Lax）2Ir3Ge5（0 ≤ x ≤ 0.66） system. It was found that the Neel temperature TNdecreases with increasing La content x, and reaches 0 K near a critical content xcr =0.6. A new phase diagram was constructed based on these measurements. A non-Fermi liquid behavior in ρ（T） and a log T relationship in C（T） were found in the samples near xcr, indicating them to be near an AFM quantum critical point（QCP） with strong spin fluctuation. Our finding indicates that（Ce（1-x）Lax）2Ir3Ge5 may be a new platform to search for unconventional superconductivity.

Performance, Immune, and Carcass Characteristics of Broiler Chickens as Affected by Thyme and Licorice or Enzyme Supplemented Diets

Numbers of 300 day-old broiler chickens through a CRD design with 5 treatments, 3 replicates and 20 chicks in each pen were used to evaluate the effect of thyme (T), licorice (L), thyme + licorice (TL), and enzyme supplemented (E) diets on performance, immune and carcass characteristics. According to the results, performance traits, immune indices, and carcass traits in herbal medicine and enzyme supplemented diets were improved significantly than control diet (P < 0.05). Weight gain and FCR in T and E groups were significantly higher and lower than other groups respectively (P < 0.05). Internal organs such as abdominal fat and liver weight as indicators of lipogenesis rate were decreased in T, L, and TL diets than control or E diet significantly (P < 0.05). Immune organs such as burse and spleen weight as indicators of immune situation were increased in TL diet than other treatments significantly (P < 0.05). These findings indicated that thyme and licorice singly or in combination as organic herbal medicine can affect performance, carcass and immune characteristics. Also an improved immune organ such as burse or spleen in this study indicates that this herbal medicine can promote the immune situation and efficacy of health and livability.

Dielectric and magnetic properties of(Zn, Co) co-doped SnO_2 nanoparticles

Polycrystalline samples of（Zn, Co） co-doped SnO2 nanoparticles were prepared using a co-precipitation method. The influence of（Zn, Co） co-doping on electrical, dielectric, and magnetic properties was studied. All of the（Zn, Co） co-doped SnO2 powder samples have the same tetragonal structure of SnO2. A decrease in the dielectric constant was observed with the increase of Co doping concentration. It was found that the dielectric constant and dielectric loss values decrease, while AC electrical conductivity increases with doping concentration and frequency. Magnetization measurements revealed that the Co doping SnO2 samples exhibits room temperature ferromagnetism. Our results illustrate that（Zn, Co） co-doped SnO2 nanoparticles have an excellent dielectric, magnetic properties, and high electrical conductivity than those reported previously, indicating that these（Zn, Co） co-doped SnO2 materials can be used in the field of the ultrahigh dielectric material, high frequency device, and spintronics.

Optimizing the utilization of maize silage in forage blends-based rations to improve production performance and reduce methane emissions from fattening calves

This research investigated the effect of various mixtures of maize silage and ryegrass fodder on nutrient digestibility,production performance,and methane(CH4)emission of fattening calves.Twenty-four fattening calves((228±10)kg body weight(BW),(280±5)d of age)were allocated to 8 diets for 84 d,according to a randomized complete block design,and the blocks were balanced for BW,age,and sex.The diets consisted of 4 levels of maize silages,i.e.,40%(MS40),50%(MS50),60%(MS60),and 70%(MS70)in the maize silage and ryegrass fodder mixture on a dry matter(DM)basis,and each of the mixture was supplemented with either low(LC,1.0%BW)or high(HC,1.5%BW)levels of fattening concentrate.The results revealed greater(p<0.05)intakes of DM(8.35 kg/d),organic matter(OM,7.85 kg/d),and metabolizable energy(ME,12.00 Mcal/d)in calves fed with MS70-LC diet.The highest(p<0.05)digestibility(g/100 g)of DM(65.2),OM(67.3),crude protein(69.1),and neutral detergent fibre(56.3)was recorded for MS40-HC diet.The maximum(p<0.05)average daily gain(ADG,571 g/d)was recorded for diet MS70-LC.The lowest value(p<0.05)of CH4 emission was recorded in MS70-LC,MS70-HC,and MS60-HC as compared to other diets.Including 70%maize silage in the ryegrass-maize silage based diet improved ADG by 174 g/d with LC feeding.It is concluded that the optimum inclusion level of maize silage and ryegrass in the fattening ration can improve animal production performance and reduces CH4 production and concentrate requirements of fattening calves.

Large unsaturated positive and negative magnetoresistance in Weyl semimetal TaP

After successfully growing single-crystal TaP, we measured its longitudinal resistivity （Pxx） and Hall resistivity （Pyx） at magnetic fields up to 9 T in the temperature range of 2-300 K. At 8 T, the magnetoresistance （MR） reached 3.28 ×10^5% at 2 K, 176% at 300 K. Neither value appeared saturated. We confirmed that TaP is a hole-electron compensated semimetal with a low carrier concentration and high hole mobility ofμh=3.71 × 105 cm2/V s, and found that a magnetic-field-induced metal-insulator transition occurs at room temperature. Remarkably, because a magnetic field （H） was applied in parallel to the electric field （E）, a negative MR due to a chiral anomaly was observed and reached -3000% at 9 T without any sign of saturation, either, which is in contrast to other Weyl semimetals （WSMs）. The analysis of the Shubnikov-de Haas （SdH） oscillations superimposed on the MR revealed that a nontrivial Berry＇s phase with a strong offset of 0.3958, which is the characteristic feature of charge carriers enclosing a Weyl node. These results indicate that TaP is a promising candidate not only for revealing fundamental physics of the WSM state but also for some novel applications.