Pharmacokinetics and Pharmacodynamics of a Depolymerized Glycosaminoglycan from Holothuria fuscopunctata,a Novel Anticoagulant Candidate,in Rats by Bioanalytical Methods

dHG-5 (Mw 5.3 kD) is a depolymerized glycosaminoglycan from sea cucumber Holothuria fuscopunctata. As a selective inhibitor of intrinsic Xase (iXase), preclinical study showed it was a promising anticoagulant candidate without obvious bleeding risk. In this work, two bioanalytical methods based on the anti-iXase and activated partial thromboplastin time (APTT) prolongation activities were established and validated to determine dHG-5 concentrations in plasma and urine samples. After single subcutaneous administration of dHG-5 at 5, 9, and 16.2 mg/kg to rats, the time to peak concentration (T_max) was at about 1 h, and the peak concentration (C_max) was 2.70, 6.50, and 10.11 μg/mL, respectively. The plasma elimination half-life(T_1/2β) was also about 1 h and dHG-5 could be almost completely absorbed after s.c. administration. Additionally, the pharmacodynamics of dHG-5 was positively correlated with its pharmacokinetics, as determined by rat plasma APTT and anti-iXase method, respectively. dHG-5 was mainly excreted by urine as the unchanged parent drug and about 60% was excreted within 48 h. The results suggested that dHG-5 could be almost completely absorbed after subcutaneous injection and the pharmacokinetics of dHG-5 are predictable. Studying pharmacokinetics of dHG-5 could provide valuable information for future clinical studies.     

川西北地区上二叠统吴家坪组凝灰岩分布地震预测

通过对川西北地区的老井进行复查,发现多口井在上二叠统吴家坪组存在大套的凝灰岩,对上述井的地质、测井、地震资料综合分析发现,凝灰岩的岩性以凝灰质泥岩、凝灰质粉砂岩、凝灰质灰岩、沉凝灰岩、凝灰岩、凝灰质白云岩为主,次生溶蚀孔隙发育;凝灰岩在测井曲线和地震剖面上均有明显的响应特征:在测井曲线上表现为明显的低纵波速度、高自然伽马特征,凝灰岩底界在地震剖面上均表现为波峰反射特征.为此,采用模型正演分析技术及波阻抗反演技术,首次对四川盆地川西北地区晚二叠世吴家坪组凝灰岩的分布进行了地震预测:双鱼石构造-剑阁区块的北部地区凝灰岩分布最厚,南部减薄;双鱼石构造东部凝灰岩分布较厚,西部减薄,直至不发育.研究结果表明,晚二叠世吴家坪组在川西北地区沉积了一套凝灰岩,从西北至东南方向减薄;由于凝灰岩物性好,孔隙度高,可成为四川盆地火山岩气藏勘探全新的后备领域,为川西北地区下一步新的勘探领域开发提供了重要研究基础.     

土壤管理措施对坡耕地侵蚀退化耕层的恢复作用

【目的】紫色土坡耕地土壤侵蚀严重,研究土壤管理措施对不同侵蚀程度坡耕地耕层侵蚀恢复作用,为紫色土坡耕地耕层质量调控和坡耕地持续利用提供理论及实践依据。【方法】采用单因素方差分析（One-way ANOVA）检验各指标的差异显著性,研究不施肥（CK）、施化肥（F）、施生物炭+化肥（BF）3种土壤管理措施对侵蚀0 cm（S_-0）、侵蚀5 cm（S_-5）、侵蚀10 cm（S_-10）、侵蚀15 cm（S_-15）、侵蚀20 cm（S_-20） 5个不同侵蚀程度坡耕地耕层土壤属性的恢复作用。【结果】（1）随侵蚀程度增加,土壤砂粒含量由38.1%—42.4%逐渐增至44.2%—46.4%,土壤黏粒含量由12.6%—14.8%逐渐减少至9.6%—11.0%;与S_-0、S_-5、S_-10相比,S_-15、S_-20土壤容重显著增大;S_-10侵蚀程度下,土壤抗剪强度最大,在8.71—9.56 kg·cm^-2之间;F、BF处理下S_-15侵蚀程度的土壤稳定入渗率、平均入渗率降幅均最大。（2）不同管理措施下坡耕地耕层土壤属性差异显著,BF处理下土壤砂粒含量小、黏粒含量最大,0—10 cm、10—20 cm土层土壤容重显著低于CK（P<0.05）,土壤总孔隙度、毛管孔隙度均显著高于CK、F处理;BF处理下土壤初始入渗率、稳定入渗率、平均入渗率均最大,CK处理最小;与CK处理相比,BF处理土壤抗剪强度显著增大。（3）随侵蚀程度增加,土壤可蚀性K值显著下降,与S_-0相比,S_-20侵蚀程度下土壤可蚀性K值下降0.1960%—0.2192%;BF处理下土壤可蚀性K值最大,F处理次之,CK最小;S_-10侵蚀程度下F、BF处理的K值均较CK增加幅度最大,分别增加0.0684%、0.1404%。【结论】施加生物炭+化肥在改善土壤物质组成、结构特征、提高土壤蓄渗性能等方面较单施化肥效果更为显著,可有效减轻紫色土坡耕地耕层土壤侵蚀,对侵蚀10 cm条件下的坡耕地耕作层（0—20 cm）土壤的改良效果最佳。     

Intestinal Microbiota in Large Yellow Croaker,Larimichthys crocea,at Different Ages

The polymerase chain reaction–denaturing gradient gel electrophoresis (PCR‐DGGE) of 16S ribosomal RNA gene was used to investigate bacterial communities in the intestines of large yellow croaker at six different ages (12 d, 18 d, 26 d, 40 d, 3 mo, and 1 yr old) as well as within the corresponding feed and culture water. In addition, Illumina Miseq sequencing was utilized to compare intestinal microbiota between 12‐d‐old and 1‐yr‐old individuals. PCR‐DGGE results revealed that the culture water had the highest bacterial diversity, followed by the feed, while the intestines had the lowest diversity. The intestinal microbiota at six ages changed severely; however, the change did not follow any trend. The large yellow croaker intestines harbored specific bacterial communities that differed from those in both feed and water. Illumina Miseq sequencing results revealed that the diversity of intestinal bacteria in 12‐d‐old fish was higher than that in 1‐yr‐old fish, and the bacterial composition differed significantly between them. γ‐Proteobacteria and Pseudoalteromonas supplied the most abundant phylum and genus in the 12‐d‐old fish intestine. However, in the 1‐yr‐old fish intestine, Firmicutes and Clostridium were the most dominant, respectively. The study may contribute to a better understanding of gut microbiota and dynamics of the large yellow croaker and the relationship with their surrounding environment.     

桑植县茶产业现状及发展对策

通过对桑植县茶产业现状进行实地考察调研,剖析桑植县茶产业发展的优势与不足,提出桑植县茶产业发展的对策措施。     

Nitrogen removal characteristics of <Emphasis Type="Italic">Pseudomonas stutzeri</Emphasis> F11 and its application in grass carp culture

This study was designed to investigate the denitrification characteristics of Pseudomonas stutzeri F11 under different environmental conditions and to evaluate the effect of these characteristics on nitrogen removal and the water microbiome in an experimental grass carp aquaculture system. The results showed that the optimal growth conditions of strain F11 were (1) ammonia-nitrogen (N), nitrite-N, or nitrate-N as sole N source; (2) initial ammonia-N concentration of 10–30 mg N/l; (3), initial nitrite-N concentration of 200 mg N/l; (4) sodium citrate as carbon source; (5) rotation (r) speed of 200 r/min; a C:N ratio of between 2 and 10; (6) culture at 32–37 °C. The addition of P. stutzeri F11 to the experimental grass carp aquaculture system reduced the levels of ammonia-N, nitrite-N, and total N in the water over an extended range, but had no effect on nitrate-N level. Results of the 454 pyrosequencing analysis indicated that the structure of the microbial community in the aquaculture water changed significantly after the addition of P. stutzeri F11 preparations. The addition of P. stutzeri F11 to the aquaculture system also altered the microbiome metabolism in the water, especially the bacteria involved in nitrogen metabolism. These results suggest that the addition of P. stutzeri F11 to an experimental grass carp aquaculture system decrease nitrogen levels and alter the microbial community structure of the water; as such, this bacterial strain could be a potential candidate for the regulation of water quality in aquaculture systems.     

乡村振兴人才队伍建设存在的问题与对策研究

党的十九大提出了乡村振兴战略，人才振兴是乡村振兴的关键。目前乡村人才队伍存在总体规模偏少、整体素质偏低、后备力量不足等问题。文章结合这些实际问题，提出相应的对策建议，以期助力乡村振兴人才队伍建设。     

早春低温之前喷施外源调控物质对冬小麦的干物质转运、产量和品质的影响

为明确外源调控物质对冬小麦早春低温抵御能力的调控效应，以济麦22为试验材料，在拔节期倒春寒来临前以喷施清水为对照（CK），设喷施氨基酸水溶肥（200倍液，T1）、蔗糖（500倍液，T2）、0.004%芸苔素内酯（800倍液，T3）及其等倍混合液（200倍液氨基酸水溶肥+500倍液蔗糖+800倍液芸苔素内酯，T4）4个调控处理，分析了拔节期发生倒春寒条件下不同调控处理间冬小麦干物质积累、转运、分配、产量及其构成和籽粒品质的差异。结果表明，T4处理下冬小麦开花期、成熟期干物质积累量较CK显著增加，且成熟期籽粒、穗轴及颖壳、茎鞘及叶的干物质积累量均高于其他处理；T2、T3、T4处理使小麦结实率均显著提高；T4处理在不降低穗粒数和穗数的前提下，显著提高千粒重和籽粒产量；T1处理有利于提高小麦籽粒蛋白质含量。由此得出，在冬小麦拔节期倒春寒来临前，喷施氨基酸水溶肥+蔗糖+0.004%芸苔素内酯混合液有助于提高小麦抵御低温逆境的能力，实现抗逆稳产。