An optimal dietary non-phytate phosphorus level of broilers fed a conventional corn–soybean meal diet from 4 to 6 weeks of age

It is imperative to evaluate precise nutrient requirements of animals in order to optimize productivity and minimize feed cost and nutrient excretions. The current non-phytate phosphorus (NPP) recommendation for broilers is based on the papers published 30 years ago. However, today’s commercial birds are quite different from those before 30 years. Therefore, the present experiment was conducted with growing male broiler chickens to evaluate an optimal dietary NPP level of broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age. The 1-day-old chicks were fed corn–soybean meal diet containing 0.39% NPP from 1 to 3 weeks of age. At 22 days of age, 360 birds were selected and randomly allotted by BW to one of 10 dietary treatments with six replicate cages of six birds per cage for each treatment. Birds were fed the P-unsupplemented corn–soybean meal basal diet and the basal diet supplemented with inorganic P as CaHPO₄·H₂O ranging from 0.00% to 0.45% with 0.05% increment from 4 to 6 weeks of age. The dietary NPP levels were 0.09%, 0.14%, 0.20%, 0.24%, 0.30%, 0.34%, 0.38%, 0.45%, 0.49% and 0.54%, respectively, and the dietary Ca level was fixed at 0.90% for all treatments. The results showed that average daily gain, serum inorganic P concentration, tibia bone strength, tibia ash percentage and P percentage, tibia bone mineral content (BMC) and density (BMD), middle toe ash percentage and P percentage, middle toe BMC, total body BMC and BMD were affected (P<0.0001) by dietary NPP level, and increased linearly (P<0.0001) and quadratically (P<0.003) as dietary NPP levels increased. Optimal dietary NPP levels estimated based on fitted broken-line models (P<0.0001) of the above indices are 0.21%, 0.29%, 0.29%, 0.29%, 0.29%, 0.31%, 0.29%, 0.30%, 0.27%, 0.29% and 0.28%, respectively. It is suggested that the total body BMC and BMD, and middle toe ash P and BMC might be new, sensitive and non-invasive criteria to evaluate the dietary NPP requirements of broilers. The optimal dietary NPP level would be 0.31% for broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age.     

Combined effect of glycerol concentration and cooling velocity on motility and acrosomal integrity of boar spermatozoa frozen in 0.5 ml straws

The interaction of glycerol concentrations of 0-10% and cooling rates from 1 to 1,500 degrees C/min with boar spermatozoa motility and acrosomal integrity (proportion of spermatozoa with normal apical ridge) was studied after thawing 0.5 ml straws at a constant rate. While increasing the glycerol concentration from 0 to 4% progressively improved motility, the percentage of spermatozoa with a normal apical ridge gradually decreased. The magnitudes of the respective changes depended on cooling rate. A peak value of 48.1% and rating 3.8 were obtained in semen protected with 4% glycerol, frozen at 30 degrees C/min. Increasing the glycerol levels above 6% resulted in a gradual decrease in motility. The proportion of spermatozoa with normal apical ridge was highest in semen protected with 0-1% glycerol after cooling at 30 degrees C/min (64.4% and 66.1%, respectively), but at these glycerol concentrations the percentage of motile spermatozoa was low. At the 30 degrees C/min cooling rate, the decline in the proportion of cells with normal apical ridge due to increasing the glycerol levels to 3 and 4% was relatively slow (57.3% and 49.4%, respectively). Cooling at 1 degrees C/min was detrimental to acrosomal integrity, which decreased with increasing glycerol concentration, in contrast to increasing motility, which even at its maximum, remained low. The direct plunging of straws into liquid nitrogen (1,500 degrees C/min) resulted in damaged acrosomes in all spermatozoa with the total loss of motility. Balancing motility and acrosomal integrity, freezing boar semen protected with 3% glycerol by cooling at 30 degrees C/min resulted in optimal survival for boar semen frozen in 0.5 ml French straws.     

漆酶同工酶基因在斑玉蕈生长发育过程中的表达分析

为了探明漆酶在斑玉蕈生长发育过程中的功能,对斑玉蕈转录测序预测的13个漆酶基因序列进行分析、鉴定和构建分子系统发育树;检测了不同生长发育时期漆酶的活性和漆酶基因表达水平。研究结果显示：13个基因片段中有10个是漆酶基因。不同的漆酶同工酶之间进化关系存在明显差异,大多数漆酶与木腐菌（金针菇Flammulina filiformis和侧耳属Pleurotus）进化关系较近。对斑玉蕈不同生长发育时期的酶活检测结果显示,从斑玉蕈的菌丝恢复期到钉头期,漆酶活性逐渐升高,而在子实体形成后期酶活逐渐降低。对培养40d、60d和80d的菌丝样品以及不同生长发育时期的样品进RT-qPCR检测,结果显示在菌丝营养生长时期,大多数漆酶基因在第40-60天表达量持续增加1-3倍,而在第60-80天时表达量出现降低的情况。而在生殖生长时期,大多数漆酶基因在转色期或者原基期相对表达量达到最大值,并在子实体期出现降低,这与漆酶活性的检测具有一致性。lcc3、lcc7、lcc8和lcc9在斑玉蕈生殖生长过程中相对表达量出现了10-100倍的上调。这说明从菌丝培养到菌丝扭结形成子实体和子实体发育的过程中,不同的漆酶可能发挥着不同的作用,表达量较高的漆酶基因可能对基质降解和子实体形成起主要作用。     

Elucidating the Role of a Tetrafluoroborate‐Based Ionic Liquid at the n‐Type Oxide/Perovskite Interface

Halide perovskites are currently one of the most heavily researched emerging photovoltaic materials. Despite achieving remarkable power conversion efficiencies, perovskite solar cells have not yet achieved their full potential, with the interfaces between the perovskite and the charge‐selective layers being where most recombination losses occur. In this study, a fluorinated ionic liquid (IL) is employed to modify the perovskite/SnO₂ interface. Using Kelvin probe and photoelectron spectroscopy measurements, it is shown that depositing the perovskite onto an IL‐treated substrate results in the crystallization of a perovskite film which has a more n‐type character, evidenced by a decrease of the work function and a shift of the Fermi level toward the conduction band. Photoluminescence spectroscopy and time‐resolved microwave conductivity are used to investigate the optoelectronic properties of the perovskite grown on neat and IL‐modified surfaces and it is found that the modified substrate yields a perovskite film which exhibits an order of magnitude lower trap density than the control. When incorporated into solar cells, this interface modification results in a reduction in the current–voltage hysteresis and an improvement in device performance, with the best performing devices achieving steady‐state PCEs exceeding 20%.     

A Review on Additives for Halide Perovskite Solar Cells

Additives are widely adopted for efficient, stable, and hysteresis‐free perovskite solar cells and play an important role in various breakthroughs of perovskite solar cells (PSCs). Herein the various additives adopted for PSCs are reviewed and their functioning mechanism and influence on device performance is described. The main roles of additives, modulating morphology of perovskite films, stabilizing phase of formamidinium (FA) and cesium (Cs)‐based perovskites, adjusting energy level alignment in PSCs, suppressing nonradiative recombination in perovskites, eliminating hysteresis, enhancing operational stability of PSCs, are summarized.     

PPARγ与c/EBPα基因在苏太猪不同组织中的表达水平探究

为探究PPARγ与c/EBPα基因在苏太猪不同组织中的表达与脂肪沉积的关系,本实验以10月龄苏太猪为研究对象,运用实时荧光定量PCR (q RT-PCR)技术检测PPARγ与c/EBPα基因mRNA在苏太猪心、肝、脾、肺、肾、胃、背最长肌和皮下脂肪8个组织中的表达水平。结果表明,PPARγ与c/EBPα基因在苏太猪的8个组织中均有不同程度的表达,其中,PPARγ基因在苏太猪脾脏组织中的表达量最高,皮下脂肪中的表达水平仅次于脾;以背最长肌中PPARγ基因的相对表达量作对比,背最长肌与脾、肺和皮下脂肪的相对表达差异极显著(p<0.01),其余为差异不显著(p>0.05),表达量高低顺序为脾>皮下脂肪>肺>心>胃>肾>肝>背最长肌;c/EBPα基因在苏太猪的皮下脂肪的表达量最高,以背最长肌中c/EBPα基因的相对表达量作对比,在肝、脾、皮下脂肪组织中表达差异极显著(p<0.01),肺的相对表达差异显著(p<0.05),其余组织中差异不显著(p>0.05),表达量的高低顺序为皮下脂肪>肝>脾>肺>肾>心>胃>背最长肌。两基因在各组织中表达趋势趋于一致。试验结果表明PPARγ和c/EBPα基因可能对猪脂肪沉积有重要影响。