声学指数在城市森林鸟类多样性评估中的应用

鸣声是鸟类之间进行沟通和传递信息的重要方式,这为通过声学监测评估鸟类多样性提供了独特的机会。利用声学指数快速评估生物多样性是一种新兴的调查方法,但城市森林中的复杂声环境可能会导致声学指数的指示结果出现偏差。为了解声学指数在城市森林中应用的可行性,本研究在北京市东郊森林公园设置了50个矩阵式调查样点,于2021年4–6月每月进行1次鸟类传统观测和同步鸣声采集,通过比较两种方法的结果来探究声学监测的有效性。采用Spearman相关分析和广义线性混合模型评估6个常用声学指数与鸟类丰富度和多度的关系,并衡量了每个指数的性能。结果表明:(1)本研究共记录到鸟类10目23科35种,通过声学监听识别的总物种数与传统鸟类观测相等,但具体鸟种存在差异;(2)不同月份间声学指数与鸟类丰富度和多度的相关性有明显差别,声学复杂度指数(ACI)和标准化声景差异指数(NDSI)优于其他指数,是评估鸟类多样性的关键变量;(3)声学指数对鸟类多度的预测能力(R²m=0.32,R2c=0.80)要高于丰富度(R²m=0.12,R2c=0.18)。声学指数为快速评估生物多样性提...     

新一代植物志的起点——读《中国维管植物科属词典》《中国维管植物科属志》的几点思考

<正>中国是全球生物多样性大国,也是世界上植物种类最多的国家之一。据《中国生物物种名录》(2022版)(http://www.sp2000.org.cn/Co LChina)记载,中国产高等植物物种总计483科4,275属38,287种及7,506个种下类群,其中维管植物占绝对优势,共有323科3,643属35,179种及7,258个种下类群,且仍以平均每年220个新分类群及32个国家级分布新记录的速度持续增长(Du et al,2020)。     

经济杀菌灭藻剂OACL控制工业循环水中有害微生物的研究

研究了经济杀菌灭藻剂OACL对异氧菌、硫酸盐还原菌和铁细菌的杀菌作用。结果表明,在实验室条件下,其杀菌率平均为99％以上,在pH5和pH7时分别为97.8％和88％。而在现场投药试验条件下为92％以上。可以认为,OACL是一种新型的、经济的高效杀菌灭藻剂。     

广椭牛齿兰，中国兰科一新记录种

报道了在海南热带雨林国家公园内发现的兰科牛齿兰属中国一新记录种：广椭牛齿兰[Appendicula ovalis(Schltr.) J.J.Sm. ex Mansf.]。该种原分布于马来半岛、苏门答腊岛、爪哇岛、婆罗洲、苏拉威西岛,在形态上与国内记录的4种牛齿兰属植物均有较大差别,如茎中部具分枝、叶广椭圆形、单个花序仅着生1朵花、且唇瓣扭转具粉紫色斑块等特征。对产自海南的该种形态和生境进行了详细描述,并提供高清解剖照片。凭证标本保存于海南大学林学院教学标本馆(HUFB)。     

N-Heterocyclic Carbene-Palladium Polymers Network: Recyclable Pre-catalyst for Effective Suzuki–Miyaura Coupling Reaction in Water

Rational design of high-efficiency N-heterocyclic carbene (NHC) palladium catalyst is of great importance to modern organic synthesis, especially in chemical and pharmaceutical industries. Herein, we fabricate a polymer network containing N-heterocyclic carbene palladium (PNNHC-Pd) catalytic active sites via an immobilization process. The N-heterocyclic carbene palladium can serve as a promising linkage of polymer network as well as an effective catalytic active site owing to its structural preference and strong σ-donating ability with palladium species. The results display that N-heterocyclic carbene palladium disperses homogeneously in polymer network, thus rendering PNNHC-Pd excellent catalytic activity, high stability and superior reusability in palladium-catalyzed Suzuki–Miyaura coupling reaction in aqueous medium. This work provides a new insight into the development of heterogenization of homogeneous catalysts based on polymer network.     

山西蕨类植物区系及分布特点的初步研究

本文对山西省蕨类植物区系成分进行了初步分析并总结了其区系特征,同时对其生态分布特点也进行了归纳,而且还对蕨类植物资源的开发利用提出了建议。     

Preparation and Characterization of a Silk Fibroin/Polyurethane Fiber Blend Membrane Containing Actinomycin X2 with Excellent Mechanical Properties and Enhanced Antibacterial Activities

Development of suitable antimicrobial biomaterials for hygienic wound dressing and healing is an important requirement for medical application. Durable mechanical properties increase the application range of biomaterial in different environmental and biological conditions. Due to the inherent brittleness of silk fibroin (SF), polyurethane fiber (PUF) was used to modify SF containing actinomycin X2 (Ac.X2) to prepare silk fibroin@actinomycin X₂/polyurethane fiber (ASF/PUF) blend membranes. The ASF/PUF blend membrane was developed by solution casting method. Incorporation of PUF improved the flexibility of material and introduction of Ac.X2 has increased antibacterial activity of materials. Excellent mechanical properties (tensile strength up to 25.7 MPa and elongation at break up to 946.5 %) of 50 % SF+50 % PUF blend membrane were proved by tensile testing machine. FT-IR spectra, TGA, contact angle and DMA were tested to prove the blend membrane's physico-chemical characteristics. ASF/PUF blend membrane displayed satisfactory antibacterial activity against S. aureus, and the cytotoxicity tests showed that the blend membrane has better biosafety compared to directly applied Ac.X2 in soluble form. These results suggest that the modification of SF through PUF for development of flexible antibacterial membranes has great potential application value in the field of silk-like material fabrication.     

相关遗传力抽样方差的估计

本文给出了单因子组和系统模型下有关相关传力及相关环境力抽样方差的估计方法。有关该参数在育种中的潜在应用其它与遗传相关之产间的相互关系也给予了一定的讨论。概括地来讲,相关遗传力具有遗传力和遗传相关的双重特征。遗传力是相关遗传力的一个特例而相关遗传力则是遗传力概念本身的扩展。用相关遗传力来表达性状间的相关遗传变异要比通常所用的遗传相关更准确一些。     

Phytoconstituents of Selaginella effusa Alston and Their α-Glucosidase as well as Urease Inhibitory Activities

Three new compounds ( 1 – 2 , 14 ), as well as 22 known compounds ( 3 – 13 , 15 – 25 ), were extracted for the first time from the Selaginella effusa Alston (S. effusa). For the unknown compounds, the planar configurations were determined via NMR and by high-resolution mass spectrometry, while their absolute configurations were determined by calculated electronic circular dichroism (ECD), and the configuration of the stereogenic center of biflavones 4 – 5 were established for the first time. The pure compounds ( 1 – 25 ) were tested in vitro to determine the inhibitory activity of the enzyme-catalyzed reactions. Compounds 1 – 9 inhibited α-glucosidase with IC₅₀ values ranging from 0.30±0.02 to 4.65±0.04 μM and kinetic analysis of enzyme inhibition indicated that biflavones 1 – 3 were mixed-type α-glucosidase inhibitors. Compounds 12 – 13 showed excellent inhibitory activity against urease, with compound 12 (IC₅₀=4.38±0.31 μM) showing better inhibitory activity than the positive control drug AHA (IC₅₀13.52±0.61 μM). In addition, molecular docking techniques were used to simulate inhibitor-enzyme binding and to estimate the binding posture of the α-glucosidase and urease catalytic sites.     

Design,Synthesis, and Cytotoxic Activities of Indole and Indazole-Based Stilbenes

To develop new highly effective anticancer agents derived from naturally occurring stilbene scaffold, in total of 24 indole and indazole-based stilbenes including 17 new compounds were designed according to molecular hybridization strategy and synthesized via Witting reaction. The cytotoxic screening results against human tumor cell lines (K562 cells and MDA-MB-231 cells) showed that indole and indazole-based stilbenes are of great interest for developing anticancer agents as eight derivatives possessed strong antiproliferative activities with IC₅₀ values less than 10 μM, and those synthetic derivatives displayed more higher cytotoxicities against K562 cells than MDA-MB-231 cells. In particular, indole-based stilbene bearing piperidine exhibited the most potent cytotoxicities against both K562 and MDA-MB-231 cells with IC₅₀ values 2.4 μM and 2.18 μM, respectively, along with a remarkable selectivity towards human normal L-02 cells. Together, the results suggested that indole and indazole-based stilbenes are promising anticancer scaffolds worthy of further investigation.