添加生物质炭对桉树人工林土壤磷组分及转化的影响

为改善我国亚热带桉树人工林土壤磷(P)供应不足的状况,该研究利用生物质炭(BC)作为土壤改良剂,以桉树人工林(林龄为15年)土壤为研究对象,通过室内培养试验,分别加入不同用量 [0(CK)、2%、5%、10%和20%]的BC,重点探究不同用量BC对土壤P组分及转化的影响及其与土壤理化性质之间的关系。结果表明:(1)与CK相比,20%的BC添加量显著提高了土壤硝态氮(NO₃^--N)、全磷(TP)、微生物生物量磷(MBP)含量和pH值(P<0.05),而2%、5%和10%的BC添加量仅显著提高了MBP和pH值(P<0.05),对其他土壤理化指标无显著影响。(2)与CK相比,2%的BC添加量显著提高了易利用性磷(LP)(P<0.05),5%和10%的BC添加量显著提高了速效磷(AP)和LP(P<0.05),20%的BC添加量显著提高了AP、LP和难利用性磷(OP)(P<0.05),但中等程度利用性磷(MP)在4种BC添加量下均无显著变化。(3)与C、N和P转化相关的β-葡萄糖苷酶(BG)、β-N-乙酰氨基葡萄糖苷酶(NAG)、蛋白酶(LAP)和酸性磷酸酶(ACP)活性均在10%和20%的BC添加量下显著高于CK(P<0.05)。(4)相关分析结果表明,ln(BG)和ln(NAG+LAP)均与ln(ACP)呈显著正相关(P<0.05); 冗余分析(redundancy analysis,RDA)表明,pH、TN和TP是驱动桉树人工林土壤P组分变化的最主要因素; 结构方程模型(structural equation model,SEM)进一步表明,pH、C:P和N:P是驱动土壤P转化的最关键因子。综上所述,不同用量BC主要通过影响土壤理化性质提高与C、N循环相关的酶活性,并在一定程度上改善桉树人工林土壤的P供应潜力,其中以高浓度BC添加量(20%)的效果最佳。该研究对指导我国桉树人工林土壤养分管理及促进林业可持续发展具有重要意义。     

访花昆虫红腹毛蚊触角感器扫描电镜观察

【目的】本研究旨在明确访花昆虫红腹毛蚊Bibio rufiventris触角感器的类型和分布。【方法】通过扫描电镜(scanning electron microscope, SEM)观察红腹毛蚊雌、雄成虫触角感器的种类、数量和形态,比较雌雄个体间的差异。【结果】红腹毛蚊雌、雄成虫触角均包含3部分,分别为柄节、梗节和鞭节,其中鞭节由8个亚节组成。雌成虫触角平均总长度为862.556±78.662μm,雄成虫触角平均总长度为880.361±83.253μm,雌、雄成虫触角各亚节的长度几乎相似,只有鞭节第8亚节长度有显著差异。红腹毛蚊的触角感器共有4大类,即刺形感器、锥形感器、毛形感器和B?hm氏鬃毛。其中,雌性红腹毛蚊触角感器共有6种亚型,即刺形感器、毛形感器2型、锥形感器(1, 2和4型)和B?hm氏鬃毛;雄性红腹毛蚊触角感器共有5种亚型,即刺形感器、毛形感器1型、锥形感器(2和3型)和B?hm氏鬃毛。【结论】红腹毛蚊雌、雄成虫触角感器在种类、数量以及形态特征方面存在一定差异。本研究为进一步探究红腹毛蚊触角感器的生理功能及其行为活动的分子机制提供了形态学基础。     

云南禄丰川街盆地早侏罗世早期分化蜥脚型类恐龙新材料研究*

目前中国早期分化的蜥脚型类恐龙化石主要发现于云南省禄丰市早侏罗世地层。本文描述的是一件产自禄丰川街盆地禄丰组的早期分化蜥脚型类恐龙新材料, 包括较完整的颈椎、背椎以及破碎的肩胛骨、耻骨和脚趾骨骼。本文对其进行了详细的骨骼形态学描述, 并与其他早期分化蜥脚型类进行了对比。结果表明, 在禄丰组发现的所有早期分化蜥脚型类中, 该标本与禄丰龙(Lufengosaurus)在形态上相似程度较高。系统发育分析结果显示, 该标本与Coloradisaurus和Glacialisaurus构成一个多分支, 该分支又和禄丰龙一起被归入大椎龙科。由于颈椎和背椎的椎体与椎弓未完全愈合, 推测该标本的个体发育阶段为幼年—亚成年。该标本的发现提高了大椎龙科在亚洲的属种分异度, 进一步扩充了对禄丰早侏罗世恐龙动物群的认识。     

Clinical and Prognostic Significance of Preoperative Plasma Fibrinogen Levels in Patients with Operable Breast Cancer

Purpose

Elevated plasma fibrinogen levels are associated with tumor progression and poor outcomes in different cancer patients. The objective of this study was to investigate the clinical and prognostic value of preoperative plasma fibrinogen levels in patients with operable breast cancer.

Methods

Two hundred and twenty-three patients diagnosed with breast cancer were retrospectively evaluated in this study. Plasma fibrinogen levels were examined before treatment and analyzed along with patient clinicopathological parameters, disease-free survival (DFS) and overall survival(OS). Both univariate and multivariate analyses were performed to identify the clinicopathological parameters associated with DFS and OS.

Results

Elevated preoperative plasma fibrinogen levels were directly associated with age of diagnose (≤47 vs. >47, p<0.001), menopause (yes vs. no, p<0.001), tumor size (T1&T2 vs.T3&T4, p = 0.033), tumor stage (Ⅰvs.Ⅱvs.Ⅲ, p = 0.034) and lymph node involvement (N = 0 vs. 1≤N≤3 vs. N≥4, p<0.001), but not with histological grade, molecular type and other Immunohistochemical parameters(ER, PR, HER2 and Ki-67). In a univariate survival analysis, tumor stage, tumor size, lymph node involvement (p<0.001/ p<0.001)and plasma fibrinogen (p<0.001/ p<0.001) levels were associated with disease-free and overall survival, but just lymph nodes involvement (p<0.001, hazard ratio [HR] = 2.9, 95% confidence interval [CI] = 1.6–5.3/ p = 0.006, HR = 3.2, 95% CI = 1.4–7.3) and plasma fibrinogen levels (p = 0.006, HR = 3.4, 95% CI = 1.4–8.3/ p = 0.002, HR = 10.1, 95% CI = 2.3–44.6) were associated with disease-free and overall survival in a multivariate survival analysis, respectively.

Conclusions

This study demonstrates that elevated preoperative plasma fibrinogen levels are associated with breast cancer progression and are independently associated with a poor prognosis in patients with operable breast cancer.     

中国桥弯藻科(硅藻门)的新记录植物

本文报道了采自新疆维吾尔自治区的桥弯藻科(硅藻门)中国新记录植物11种3变种,分别为Amphora mexi-canavar.major(Cleve)A.Cleve,Amphora twenteanaKrammer,Encyonema cespitosumK櫣tzing,Encyonema silesiacumvar.ventriformisKrammer,Cymbopleura albanicaKrammer et Miho,Cymbopleura apiculataKrammer,Cymbopleura schwe-ickerdtiiCholoky,Cymbella compacta strup,Cymbella diversaKrammer,Cymbella excisavar.subcapitataKrammer,Cymbella hantzschianaKrammer,Cymbella scutarianaKrammer,Cymbella subhelveticaKrammer,Cymbella vulgataKram-mer。对其分类学特征进行了详细的描述,并给出了它们的生境特征。       

Optimization of nutrient components for enhanced phenazine-1-carboxylic acid production by <Emphasis Type="Italic">gacA</Emphasis>-inactivated <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. M18G using response surface method

The nutritional requirements for phenazine-1-carboxylic acid (PCA) production using Pseudomonas sp. M18G, a gacA chromosomal-inactivated mutant of the strain M18, with a high PCA yield, were optimized statistically in shake flask experiments. Based on a single-factor experiment design, we implemented the two-level Plackett–Burman (PB) design with 11 variables to screen medium components that significantly influence PCA production. Soybean meal, glucose, soy peptone, and ethanol were identified as the most important significant factors (P < 0.05). Response surface methodology based on the Center Composite Design (CCD) was applied to determine these factors’ optimal levels and their mutual interactions between components for PCA production. The predicted results showed that 1.89 g l⁻¹ of PCA production was obtained after a 60-h fermentation period, with optimal concentrations of soybean meal powder (33.4 g l⁻¹), glucose (12.7 g l⁻¹), soy peptone (10.9 g l⁻¹), and ethanol (13.8 ml l⁻¹) in the flask fermentations. The validity of the model developed was verified, and the optimum medium led to a maximum PCA concentration of 2.0 g l⁻¹, a nearly threefold increase compared to that in the basal medium. Furthermore, the experiment was scaled up in the 10 l fermentor and 2 g l⁻¹ PCA productions were achieved in 48 h based on optimization mediums which further verified the practicability of this optimum strategy.     

局灶性脑缺血后海马齿状回神经发生及其与血管内皮生长因子关系的研究

目的研究成年大鼠局灶性脑缺血后海马齿状回（DG）神经发生的情况及其与血管内皮生长因子（VEGF）的关系,探讨脑缺血后神经发生及其调控机制。方法通过大脑中动脉阻断法（MCAO）建立大鼠局灶性脑缺血模型,以5-溴-2-脱氧尿核苷（BrdU）标记增殖的神经前体细胞（NPCs）,用免疫组化及免疫荧光双标记法动态检测脑缺血后不同时间DG神经细胞增殖及其分化,同时观察增殖细胞表达VEGF及其受体情况。结果与对照组相比,缺血侧DG的BrdU阳性细胞数在脑缺血后1d开始增加,7d达高峰,28d接近正常水平;BrdU/TuJ1、BrdU/MAP-2阳性双标细胞数在脑缺血后14d开始增加,28d达高峰;BrdU/GFAP阳性双标细胞数则无明显变化;增殖的BrdU阳性细胞同时表达VEGF及其受体FLK-1。结论大鼠局灶性脑缺血可激活DG自体NPCs原位增殖、分化,增殖的细胞同时表达VEGF及其受体可能是脑缺血后神经发生增强的调节机制之一。     

九龙江西陂库区沉积物甲藻孢囊的分布

孢囊在甲藻的生活史中发挥重要作用,福建省九龙江从2009年起,暴发多次拟多甲藻水华事件。采用显微镜观察和单细胞PCR技术,对九龙江西陂库区2012—2013年不同月份沉积物中的甲藻孢囊进行种属判定,并对甲藻孢囊的分布及其影响因素进行分析。结果表明,西陂库区沉积物中的甲藻孢囊主要为拟多甲藻属,约占80%,其次为裸甲藻属,发现了2009年水华的优势种佩式拟多甲藻(Peridiniopsis penardii)孢囊。库区沉积物中甲藻孢囊的丰度在(13.7±1.2)—(105.2±8.3)个/g干重之间。多元相关分析结果显示甲藻孢囊的丰度与含水率呈现显著正相关性(P0.05),反映了甲藻孢囊沿水流方向逐渐积累。本研究结果填补了国内水库甲藻孢囊鉴定和萌发的研究空白,为九龙江甲藻水华的防治提供科学参考。     

亚热带森林凋落叶分解过程土壤节肢动物群落的变化特征

土壤动物群落结构和多样性可能随凋落物分解进程和基质质量的变化不断改变。为了解亚热带森林凋落叶分解过程中土壤节肢动物群落变化特征,以四川盆地亚热带森林麻栎（Quercus acutissima）和柳杉（Cryptomeria fortunei）凋落叶为对象,于2011-2015年采用分解袋法研究了2种凋落叶分解过程中土壤节肢动物组成、结构和多样性动态变化。整个研究期间,柳杉和麻栎凋落叶分解袋中共捕获土壤节肢动物3855只,分属于16目51科,且均以等节跳科和棘跳科为优势类群;麻栎凋落叶中土壤节肢动物的个体密度随分解进程呈现增加趋势,在分解的1079天达最高值后降低,而柳杉凋落叶则在分解的156天急剧增加后快速降低,2种凋落叶中土壤节肢动物类群数量具有相似的动态变化过程;2种凋落叶中土壤节肢动物总体以菌食性数量比例最高,腐食性最低,且随凋落叶分解进程,植食性土壤节肢动物占比明显下降,菌食性则上升;非度量多维尺度（NMDS）分析显示,2种凋落叶中土壤节肢动物群落组成具有显著差异,聚类分析表明,2种凋落叶土壤节肢动物群落结构相似性随分解进程不断降低。亚热带森林凋落叶分解过程中土壤节肢动物群落组成、结构和多样性受凋落叶类型影响。     

3种检测吡咯喹啉醌的方法比较

目的:研究和比较3种检测吡咯喹啉醌(PQQ)的方法,确定各种方法的特点和适用范围。方法:设计和改进了3种检测PQQ的方法,分别为活性电泳法、光谱法和NBT-Gly法,探讨其检测限和线性范围、精密度、样品检测和加样回收率。结果:活性电泳法专一性好,具有很高的灵敏度,可检测到12.6 ng/mL PQQ,可靠但准确性较差;NBT-Gly法操作简便,可用于大量样品的检测,但重复性不佳;光谱法精密度较好,但样品中存在吸光物质时对检测结果影响较大。结论:活性电泳法、光谱法和NBT-Gly法均可用于PQQ的检测,活性电泳法适于培养上清等复杂样品的粗略定量,NBT-Gly法适于大量样品的检测,光谱法适于纯度较高的PQQ的定量。