航道整治期间长江江豚临时庇护所建设及效果评估

航道整治期间为受扰动江豚提供临时庇护所,是在就地保护和迁地保护之外的一种尝试。2020年1月至2021年12月,在长江干线武汉至安庆段6 m水深航道整治过程中,选取马当圆水道建设长江江豚临时庇护所,通过禁止渔业捕捞,增殖放流和通航引导等措施来提升庇护所质量。监测结果表明,庇护所设立后其作为长江江豚栖息地的质量得到提高:夏季鱼类密度从(3361.2±1991.7)条/hm²上升到(12439.1±10734.5)条/hm²,冬季鱼类密度从(501.3±381.8)条/hm²上升至(1684.4±3770.9)条/hm²。通航船舶显著减少,水下噪声低于长江干流的平均水平。长江江豚临时庇护所建立后,枯水期庇护所水域内长江江豚的平均目击次数(4.3±0.6)、观察头次(6)和群体大小(1.4±0.5)都要显著高于庇护所建设前(P<0.05),丰水期则无显著性差异(P>0.05),说明庇护所在枯水期发挥了对长江江豚的保护作用。但长江江豚对庇护所的利用主要集中在进出水道两端,可能是枯水期部分水域过浅限制了江豚对庇护所的利用。分析认为,航道整治等涉水工程施工期间为江豚提供临时庇护所是一项可行措施,但要充分发挥庇护所对江豚的保护作用,必须全面考虑江豚对各项生态因子的需求,防止因关键因子带来的"木桶效应"制约庇护所的整体适合度。     

杉木连栽土壤对其幼树生长的影响

在会同林区采用３种不同连栽杉木次数的土壤,进行杉木幼树盆栽试验．结果表明,杉木连栽不利其幼树生长．连裁使幼树高生长下降３７—４０％,基径下降１９—２８％,冠幅下降２１—２９％,总生物量减少４５—５０％．杉木连栽还造成土壤养分递减,即腐殖质减少７—２８％,速效养分下降２３—２８％,土壤微生物数量和活性也大大降低．因此,杉木纯林连栽经营方式应尽快改变．     

Near Neutral pH Redox Flow Battery with Low Permeability and Long‐Lifetime Phosphonated Viologen Active Species

A highly stable phosphonate‐functionalized viologen is introduced as the redox‐active material in a negative potential electrolyte for aqueous redox flow batteries (ARFBs) operating at nearly neutral pH. The solubility is 1.23 m and the reduction potential is the lowest of any substituted viologen utilized in a flow battery, reaching ?0.462 V versus SHE at pH = 9. The negative charges in both the oxidized and the reduced states of 1,1′‐bis(3‐phosphonopropyl)‐[4,4′‐bipyridine]‐1,1′‐diium dibromide ( BPP?Vi ) effect low permeability in cation exchange membranes and suppress a bimolecular mechanism of viologen decomposition. A flow battery pairing BPP?Vi with a ferrocyanide‐based positive potential electrolyte across an inexpensive, non‐fluorinated cation exchange membrane at pH = 9 exhibits an open‐circuit voltage of 0.9 V and a capacity fade rate of 0.016% per day or 0.00069% per cycle. Overcharging leads to viologen decomposition, causing irreversible capacity fade. This work introduces extremely stable, extremely low‐permeating and low reduction potential redox active materials into near neutral ARFBs.     

Ceramide Production Mediates Aldosterone-Induced Human Umbilical Vein Endothelial Cell (HUVEC) Damages

Here, we studied the underlying mechanism of aldosterone (Aldo)-induced vascular endothelial cell damages by focusing on ceramide. We confirmed that Aldo (at nmol/L) inhibited human umbilical vein endothelial cells (HUVEC) survival, and induced considerable cell apoptosis. We propose that ceramide (mainly C18) production might be responsible for Aldo-mediated damages in HUVECs. Sphingosine-1-phosphate (S1P), an anti-ceramide lipid, attenuated Aldo-induced ceramide production and following HUVEC damages. On the other hand, the glucosylceramide synthase (GCS) inhibitor PDMP or the ceramide (C6) potentiated Aldo-induced HUVEC apoptosis. Eplerenone, a mineralocorticoid receptor (MR) antagonist, almost completely blocked Aldo-induced C18 ceramide production and HUVEC damages. Molecularly, ceramide synthase 1 (CerS-1) is required for C18 ceramide production by Aldo. Knockdown of CerS-1 by targeted-shRNA inhibited Aldo-induced C18 ceramide production, and protected HUVECs from Aldo. Reversely, CerS-1 overexpression facilitated Aldo-induced C18 ceramide production, and potentiated HUVEC damages. Together, these results suggest that C18 ceramide production mediates Aldo-mediated HUVEC damages. MR and CerS-1 could be the two signaling molecule regulating C18 ceramide production by Aldo.     

原生质体融合技术选育分解草酸乳酸菌菌株的研究

将具有草酸分解能力的乳双歧杆菌和具有耐氧特性的嗜酸乳杆菌进行原生质体融合,其最佳条件为:50%的PEG6000,融合温度30℃,融合时间为7 min,CaCl2浓度为0.02 mol/L,MgCl2浓度为0.5 mol/L,在此条件下融合率可达7.6%。从中筛选出同时具有耐氧特性和草酸分解能力的融合子,草酸分解率为13.4%。     

杉楠混交与人工杉木林自养机制的恢复

自养机制的形成是人工林可持续经营的目标之一。本研究通过混交模拟杉木人工林不同恢复阶段林分,观察比较发现从退化的杉木林阶段到地带性树种比例较低的混交林、地带性树种比例较高的混交林和地带性树种纯林阶段凋落量、Ｎ、Ｐ、Ｋ、Ｃａ和Ｍｇ５种元素的归还量逐渐增加,特别是５种养分元素的循环速率也不断增大,其中Ｎ、Ｍｇ的循环速率由杉木纯林的０．１左右增大到火力楠纯林的０．５以上,与此同时林分土壤有机质含量和养分含     

湖南会同红栲-青冈-刨花楠群落生物生产力的研究

用回归分析方法 ,对我国亚热带湖南会同红栲 青冈 刨花楠群落的生物生产力进行了研究 ,结果表明 ,林分总生物量为 45 1.0 2t·hm-2 ,其中乔木层、灌木层和藤本生物量分别为 42 6 .76、17.76和 1.80t·hm-2 ,枯枝落叶层现存量为 4.70t·hm-2 ,乔木层净生产量和平均生产量分别为 34.46t·hm-2 ·年 -1、13 .32t·hm-2 ·年 -1.     

Plant regeneration of Chorispora bungeana via somatic embryogenesis

Summary A method was developed for in vitro regeneration of plants via somatic embryogenesis in Chorispora bungeana, an alpine plant with freeze-tolerance, using cell suspensions initiated from leaf-derived callus. Primary calli were induced from leaves of C. bungeana grown on Murashige and Skoog (MS) media supplemented with 4.0 mg l⁻¹ gibberellic acid (GA₃), 0.2 mgl⁻¹ α-naphthaleneacetic acid (NAA) and 0.2 mgl⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D). Suspension culture was initiated by incubating the callus particulates in liquid MS medium supplemented with 1.0 mgl⁻¹ kinetin (KT) and 0.2 mgl⁻¹ NAA. Individual early cotyledonary-stage somatic embryos isolated from cell suspension developed into whole plants on medium containing high levels of sucrose (60 and 90 gl⁻¹), whereas lower sucrose concentrations (0 and 30 gl⁻¹) were inhibitory to main root development. On the MS medium with 90 gl⁻¹ sucrose, one regenerated plant exhibited hetero-morphologic leaves, while other plants grown on different media showed a transformation from stem to root.