Genome-Wide Association Study for Certain Carcass Traits and Organ Weights in a Large White×Minzhu Intercross Porcine Population

Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.

Effects of Aroclor 1254 on reproductive organ weight,sperm quality and testicular mitochondria oxidative stress of Boleophthalmus pectinirostris

Boleophthalmus pectinirostris is an amphibious economic fish and wildly distributed in the southeast coast of China. In this study, Aroclor 1254 was intraperitoneally injected into B. pectinirostris with 1, 2 and 4 μg/（g · d） for 28 d to assay the reproductive organ weight, the sperm quality （sperm concentration and motility）, and the testicular mitochondrial testicular mitochondria oxidative stress. The results show that the sperm number and motility in seminal vesicles, the absolute weight of testes and seminal vesicles of B. pectinirostris treated with 2 and 4 μg/（g · d） Aroclor 1254 decreased significantly as compared to the controls （p 0.05）, while those treated with 1 μg/（g · d） Aroclor 1254 had no significant effects on these indictors. For the relative weight of reproductive organs, significant reduction （p 0.05） was only observed in the seminal vesicles of B. pectinirostris treated with 4 μg/（g · d）. SOD activities and GSH levels in all the Aroclor 1254 treatments were significantly lower than those of the controls （p 0.05）. The activities of CAT, GPx, GR and the levels of Vit C also decreased significantly in comparison with the controls （p 0.05） at the higher dose of 2 and 4 μg/（g · d） Aroclor 1254 treatments. In addition, both H 2 O 2 level and MDA content in testicular mitochondria of B. pectinirostris had a close correlation with Aroclor 1254 dosage, and were significantly higher than the controls （p 0.05）. Those indicate that Aroclor 1254 can induce the oxidative stress of testicular mitochondria, and impair the reproductive function of male B. pectinirostris.

Effects of n-3 Fatty Acids Supplementation on Performance, Relative Organ Weight and Fatty Acid Composition of Thigh Meat in Broiler Chickens

This study was conducted to evaluate the effects of dietary supplementation with marine microbe accumulating n-3 fatty acids on growth performance, relative organ weight and fatty acid composition of thigh meat in broilers. A total of 480 broilers were randomly allotted to three treat-ments with eight replications per treatment and 20 chicks per pen. A corn-soybean meal-based diet was formulated as a control diet and the broilers were then provided with one of the following dietary treatments:(1) CON(basal diet);(2) N0.1(basal diet+0.10% marine microbe accumulating n-3 fatty acids);(3) N0.2(basal diet+0.20% marine microbe accumulating n-3 fatty acids). No significant differences were observed in the growth performance or the relative organ weight among treatments. However, the levels of saturated fatty acids(SFA) and monounsaturated fatty acids(MUFA)were significantly lower(P<0.05) in groups that received the n-3 fatty acids treatments, whereas polyunsaturated fatty acids(PUFA) were increased(P<0.05) significantly in these groups. Overall, these results indicate that dietary supplementation with marine microbe accumulating n-3 fatty acids can increase PUFA and decrease SFA and MUFA in thigh meat.

Characteristics and distribution of low molecular weight organic acids in the sediment porewaters in Bosten Lake, China

The composition and vertical profiles of low molecular-weight organic acids （LMWOAs） and the contribution of them to dissolved organic matter （DOM） in sediment porewaters in Bosten Lake, Xinjiang, China were investigated. The results showed that total concentration of LMWOAs was up to 94.5 μmol/L and their proportion in DOM was 5.6%, suggesting that LMWOAs were important chemical components in DOM in lake sediment porewaters. Among the seven LMWOAs, pyruvic and acetic acid had the highest concentrations with 26.30 and 8.31 μmol/L, accounting for 51.4% and 14.92% of LMWOAs, respectively. Trifluoroacetic and sorbic acid had the lowest concentrations, indicating that the compositions of LMWOAs in relative reducing environments were largely different from those reported in glacier, atmosphere and soils. The concentrations of lactic, acetic, formic, sorbic and oxalic acid decreased with increasing depth, probably relating to stronger microbial activities in the initial stage of early diagenesis. Trifluoroacetic acid was mainly anthropogenic with its concentration, showing a diusive trend from the surface to bottom sediments. The concentrations of lactic acid and nitrate generally showed a consistent profile. The increasing concentration of pyruvic acid in the vertical profile was just opposite to that of sulfate, revealing a significant negative relationship between them. Oxalic acid remained constant except for an obvious peak at 6 cm depth. The results indicated the diversities in sources and behaviors for various LMWOAs during early diagenesis in sediments.

Dissolution of Aluminum in Variably Charged Soils as Affected by Low-Molecular-Weight Organic Acids

Low-molecular-weight (LMW) organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and Al detoxification. In this research, a batch experiment was conducted to examine the effects of LMW organic acids on dissolution of aluminum in two variably charged soils, an Ultisol and an Oxisol. The results showed that the LMW organic acids enhanced the dissolution of Al in the two investigated soils in the following order: citric > oxalic > malonic > malic > tartaric > salicylic > lactic > maleic. This was generally in agreement with the magnitude of the stability constants for the Al-organic complexes. The effects of LMW organic acids on Al dissolution were greater in the Ultisol than in the Oxisol as compared to their controls. Also, the accelerating effects of citric and oxalic acids on dissolution of Al increased with an increase in pH, while the effects of lactic and salicylic acids decreased. Additionally, when the organic acid concentration was less than 0.2 mmol L-1, the dissolution of Al changed little with increase in acid concentration. However, when the organic acid concentration was greater than 0.2 mmol L-1, the dissolution of Al increased with increase in acid concentration. In addition to the acid first dissociation constant and stability constant of Al-organic complexes, the promoting effects of LMW organic acids on dissolution of Al were also related to their sorption-desorption equilibrium in the soils.

Effect of Dissolved Organic Matter on Titanium Dioxide Nanoparticles in Aquatic Environment:Molecular Weight Fractions

At present,a growing number of consumer products contain engineered nanoparticle TiO2(nano⁃TiO2),which has resulted in the consequences of nano⁃TiO2 entering the aquatic environment directly or indirectly at some stage.The fate of nano⁃TiO2 in the aquatic environment has become the key factor which affects its safety application and nanoecotoxicology.This paper aims to investigate how the dissolved organic matters(DOM),especially the molecular weight fractions in the aquatic environment,affect the aggregation,stability,and fate of nano⁃TiO2,and the interaction mechanism of DOM and nano⁃TiO2.Results of dynamic light scattering(DLS)showed that the molecular weight of DOM molecules caused different aggregation rates of nano⁃TiO2 in aqueous solution.Fourier Transform infrared spectroscopy(FTIR)results indicated the molecular structure is characteristics of DOM fractions and the mechanisms of bonds formation between DOM and nano⁃TiO2.Results of three⁃dimensional excitation⁃emission matrices(3D⁃EEM)confirmed the FTIR results and implied the increase of the stability of theπ-πconjugated system in the presence of DOM.In addition,low molecular weight of DOM fractions appeared to show more affinity with nano⁃TiO2 than high molecular weight fractions.

Molecular Weight Distribution of Dissolved Organic Matter in Lake Hongfeng Determined by High Performance Size Exclusion Chromatography (HPSEC) With On-Line UV-Vis Absorbance and Fluorescence Detection

The molecular weight distribution (MWD) of dissolved organic matter (DOM) in lake waters from Lake Hongfeng was examined using high performance size exclusion chromatography (HPSEC) with UV-vis absorbance and fluorescence detection. The elution curves obtained by absorbance and fluorescence techniques expressed similar patterns, with the exception of diminishing of large fraction and the peaks behind several seconds in fluorescence chromatograms. According to its molecular weight (MW), DOM in water samples is divided into several fractions: large ({>3.5} kDa); medium-large ({3.5}-{2.0} kDa); medium ({2.0}-{1.0} kDa) and small ({<1.0} kDa). The average molecular weight was calculated using the elution curve detected by UV-vis absorbance and fluorescence detection techniques. The results showed that the weight-average molecular weight (Mw) and number-average molecular weight (Mn) calculated by UV-vis absorbance techniques range from 1750 to 2050 Dalton and from 1450 to 1850 Dalton, respectively. And the Mw and Mn obtained by fluorescence detection are lower by 50 to 400 Dalton. As a reference, the molecular weight of Fluka humic acid (FHA) is larger than that of water samples by about 200 Dalton. The average molecular weight of DOM for water samples collected in March and July was compared. The results revealed that the molecular weight is lower for water samples obtained in July than that obtained in March, indicating the ambient environment has an influence on the molecular weight, including photo-degradation and biological activity.

Utilizing Water Treatment Residuals for Phosphorus Removal:Batch Trials,Column Trials and Effects of Three Low-Molecular-Weight Organic Acids

Phosphorus( P) has been recognized as a major limited nutrient responsible for the eutrophication of surface waters. Water treatment residuals( WTRs) are safe by-products of water treatment plants and are cost-efficient adsorbents. In this study, batch experiments and column experiments based on WTRs were employed to study the characteristics of P adsorption and the effects of lowmolecular-weight organic acids( LMWOAs)( citric acid, oxalic acid,and tartaric acid) on P adsorption. Different models of adsorption were used to describe equilibrium and kinetic data. The adsorption data were fitted well by a pseudo-second order kinetic model. The adsorption process was determined to be controlled by three steps of diffusion mechanisms through the intra-particle model.The adsorption equilibrium was well described by the Langmuir,Freundlich,Redlich-Peterson,and Sips isotherm models. Batch and continuous flow experiments indicated that the LMWOAs exhibited inhibitory action,and as pH increased,the inhibitory action became weaker for all the three acids. The effect of LMWOAs concentration was not significant on inhibition. The effects of LMWOAs were closely related to reaction time.

Effects of Vertex Activity and Self-organized Criticality Behavior on a Weighted Evolving Network

Effects of vertex activity have been analyzed on a weighted evolving network.The network is characterized by the probability distribution of vertex strength,each edge weight and evolution of the strength of vertices with different vertex activities.The model exhibits self-organized criticality behavior.The probability distribution of avalanche size for different network sizes is also shown.In addition,there is a power law relation between the size and the duration of an avalanche and the average of avalanche size has been studied for different vertex activities.

低分子量有机酸对亚热带地区典型土壤磷吸附的影响

为探索低分子量有机酸对亚热带地区典型土壤磷吸附的影响,采用批处理法研究了柠檬酸和草酸对旱地土、水稻土磷素吸附特征的作用,重点探讨了不同浓度有机酸和柠檬酸钠、有机酸加入顺序等对土壤磷吸附的影响。结果表明:柠檬酸和草酸显著降低了土壤磷吸附动力学的颗粒内扩散模型拟合度,减弱了磷素在土壤颗粒内部扩散过程。Langmuir和Freundlich方程对有机酸存在下土壤磷吸附等温数据均有较好的拟合效果(R2=0.863~0.996)。有机酸降低了土壤磷素最大理论吸附量。土壤磷吸附量与有机酸浓度呈指数函数关系,0.1~5 mmol/L有机酸对土壤磷吸附的影响最大。有机酸浓度小于1 mmol/L时,柠檬酸对土壤磷素吸附的抑制程度大于草酸;而当浓度大于5 mmol/L时,草酸的抑制程度更大。在相同浓度时,0.1~5 mmol/L的柠檬酸钠比柠檬酸对土壤磷吸附能力抑制程度更大,先加入有机酸进一步降低了土壤对磷素吸附量,说明阴离子竞争吸附是低浓度柠檬酸降低土壤磷吸附能力的主要原因,而柠檬酸浓度为5~50 mmol/L时,有机酸与土壤铁铝等金属离子的络合作用占主导。

饲粮中添加芦丁对努比亚山羊体尺指标、瘤胃发酵和器官发育的影响

为研究饲粮中添加芦丁对努比亚山羊体尺指标、瘤胃发酵和器官发育的影响,试验选择2月龄健康、体重相近的努比亚山羊母羊36只,随机分为3组,每组12只羊。分别饲喂基础饲粮(对照组)、基础饲粮+25 mg/kg芦丁(试验Ⅰ组)和基础饲粮+50 mg/kg芦丁(试验Ⅱ组)。试验预饲期10 d,正试期60 d。饲养结束后进行屠宰。结果表明:(1)与对照组相比,正试期第10天试验Ⅰ组和Ⅱ组山羊管围分别显著提高5.57%(P<0.05)、6.93%(P<0.05),正试期第60天试验Ⅱ组管围和体高分别显著降低6.54%(P<0.05)、8.23%(P<0.05),试验Ⅱ组体长相对于Ⅰ组显著提高3.69%(P<0.05)。(2)与对照组相比,试验Ⅰ组山羊丙酸和总挥发性脂肪酸浓度分别显著降低42.14%(P<0.05)、21.62%(P<0.05)。试验Ⅱ组乙酸和总挥发性脂肪酸浓度分别显著降低29.23%(P<0.05)、29.43%(P<0.05)。(3)与对照组相比,试验Ⅰ组山羊瘤胃产琥珀酸丝状杆菌、溶纤维丁酸弧菌、乳酸菌和黄色瘤胃球菌基因相对表达量分别提高271.57%(P<0.01)、1686.09%(P<0.05)、280.00%(P<0.01)和16226.73%(P<0.01),试验Ⅱ组白色瘤胃球菌、溶纤维丁酸弧菌、栖瘤胃普雷沃菌、乳酸菌和黄色瘤胃球菌基因相对表达量分别提高130.56%(P<0.01)、381.74%(P<0.05)、188.00%(P<0.01)、546.00%(P<0.01)、25624.75%(P<0.01),嗜淀粉瘤胃杆菌基因相对表达量降低57.89%(P<0.05)。试验Ⅰ组与试验Ⅱ组嗜淀粉瘤胃杆菌、产琥珀酸丝状杆菌、白色瘤胃球菌、溶纤维丁酸弧菌、栖瘤胃普雷沃菌和乳酸菌基因相对表达量对比差异极显著(P<0.01)或显著(P<0.05),黄色瘤胃球菌基因相对表达量对比差异不显著(P>0.05)。(4)与对照组相比,试验Ⅰ组山羊心脏重量、瓣胃重量和指数分别显著降低14.50%(P<0.05)、24.00%(P<0.05)、20.00%(P<0.05),试验Ⅱ组肝脏重量和指数分别提高12.54%(P<0.01)、14.95%(P<0.01),瓣胃重量和指数分别显著降低29.41%(P<0.05)、28.57%(P<0.05)。(5)与对照组相比,试验Ⅰ组山羊十二指肠VH/CD和回肠VH分别显著降低0.13%(P<0.05)、15.42%(P<0.05),试验Ⅱ组十二指肠VH、CD、回肠VH、VH/CD分别显著降低29.19%(P<0.05)、20.92%(P<0.05)、18.23%(P<0.05)、26.14%(P<0.05),空肠CD显著提高15.63%(P<0.05)。综上所述,本试验条件下,饲粮中添加高剂量芦丁可以增加努比亚山羊部分瘤胃菌群的数量,影响瘤胃发酵,对胃肠道发育产生负面影响。

好氧堆肥污泥农用后溶解性有机质释放特征

研究污泥农用后溶解有机质(DOM)的释放特征,有助于评价和预测土壤中共存污染物的环境行为和效应。以河南省洛阳市某污泥处理厂好氧堆肥后的市政污泥作为样本,利用扫描电子显微镜(SEM)、总有机碳分析仪、紫外-可见吸收光谱(UV-Vis)、凝胶渗透色谱(GPC)、三维荧光光谱(3D-EEM)、傅里叶变换红外光谱(FTIR)和核磁共振波谱(NMR)等表征技术,研究污泥农用后释放DOM的浓度、分子量、组成和结构等性质的演变特征。结果表明,污泥还田60 d内,释放的DOM微观形貌上存在较大变化,由致密块状物变为不规则松散物质;污泥农用后释放溶解性有机碳(DOC)量在4.25~6.22 mg·g^(-1)污泥范围,呈现先上升后稳步下降的趋势;释放过程中,污泥DOM的分子量和芳香性等性质也存在显著的变化:污泥DOM重均分子量由0.5 d时2674 g·mol^(-1)的逐渐升高为60 d的129026 g·mol^(-1);污泥还田后释放的DOM分子中芳香性物质逐渐积累;3D-EEM结合平行因子分析(PARAFAC)模型分析污泥释放DOM中的荧光物质,发现DOM中荧光物质主要为类富里酸和类腐殖质,释放过程中,类腐殖质逐渐积累,DOM整体上呈现腐殖化趋势;FTIR图谱表征污泥DOM脂肪族烷烃类物质的减少和芳香烃物质生成。污泥还田后释放DOM数量和性质变化,显著改变土壤中共存污染物环境行为和生态效应。该研究可为评估和预测污泥农用后产生的环境影响提供理论依据,也对市政污泥的资源化利用具有一定指导意义。

冶炼厂周边农用地土壤重金属非致癌健康风险评估及修正

为科学量化重金属复合暴露产生的非致癌健康风险,引入靶器官毒性剂量(TTD)模型和证据权重分析模型(WOE)对传统评估模型(HRA)的非致癌健康风险进行修正,并以华中某冶炼厂周边农用地土壤重金属为例,探究3种模型对非致癌健康风险评估结果的影响。结果表明:土壤重金属镉(Cd)、铅(Pb)、铬(Cr)和砷(As)的浓度均值分别为0.37、36.65、69.06和7.66mg/kg,其中Cd、Pb和Cr不同程度超出研究区土壤背景值,4种重金属传统非致癌健康风险值(HI_(HRA))为2.27×10^(-3)~3.35×10^(-1)。经TTD模型和WOE模型修正后4种重金属HI_(TTD)和HI_(WOE)分别为1.64×10^(-2)~5.50×10^(-1)和1.08×10^(-2)~6.09×10^(-1),其中HI_(TTD)、HI_(WOE)均值分别为HI_(HRA)均值的1.88倍和1.17倍。研究显示,对多种重金属复合污染的农用地开展人体非致癌健康风险评估时,需考虑多靶器官效应及重金属间的交互作用,避免传统风险评估方法低估或高估土壤污染对暴露人群产生的实际健康损害。

新生儿序贯器官衰竭评分对极低出生体重儿晚发败血症死亡的预测价值

目的评价新生儿序贯器官衰竭评分(nSOFA)对极低出生体重儿晚发败血症死亡风险的预测价值。方法采用单中心、回顾性病例对照性研究。收集2018—2021年于南京医科大学附属苏州医院(苏州市立医院)新生儿科重症监护室住院的首次患有晚发败血症的95例极低出生体重儿确诊感染时及感染6 h后的nSOFA评分,上述患者以持续使用抗生素后发生的临床结局分为死亡组和存活组。采用受试者工作特征(ROC)曲线评估nSOFA评分对极低出生体重儿晚发败血症死亡风险的预测价值。结果感染后6 h晚发败血症死亡组nSOFA与存活组相比,差异有统计学意义(P<0.01),而在确诊感染时差异无统计学意义(P>0.05)。感染后6 h nSOFA评分预测模型ROC的AUC=0.873(95%CI 0.729~1.00,P=0.000),而确诊感染时AUC=0.541(95%CI 0.32~0.77,P=0.69)。感染后6 h nSOFA评分约登指数最大值为0.687,最佳截断值为6.5分。结论确诊败血症后6 h nSOFA能较好地预测极低出生体重儿的死亡风险。监测nSOFA对改善新生儿脓毒症预后有一定的临床价值。

蘑菇渣和稻秸堆肥中不同分子量水溶性有机物含量分布和光谱特征

分子量(MW)是影响堆肥溶解性有机物(DOM)化学性质和环境行为等的重要因素,目前关于堆肥DOM的MW分布等认识仍不清晰。以蘑菇渣堆肥(MRC)和水稻秸秆堆肥(RSC)中DOM为研究对象,采用超滤分级技术对堆肥DOM中不同MW组分进行分级定量和化学表征,进而探究不同堆肥DOM中MW组分的分布和光谱特征。DOC结果显示,MRC和RSC中DOM均以>10 kDa的高分子量(HMW)组分组成为主,分别富集有80%和71%的DOC(溶解性有机碳),而中等分子量(5~10 kDa,MMW)和低分子量(<5 kDa,LMW)组分分别占总DOC的12%~15%和9%~15%,表明HMW是决定腐熟堆肥DOM的化学组成和分子结构的关键物质。光谱特征参数(如SUVA_(254)、E_(2)/E_(3)和HIX)结果显示,不同MW的DOM的芳香化程度和腐殖化程度均呈现相同的趋势,即HMW>MMW>LMW;而BIX和FI值则呈现与之相反的分布规律。结果表明堆肥DOM中HMW(高分子组分)组分富集了较多的芳香环等不饱和共轭结构,而MMW和LMW组分具有更高的自生源贡献。三维荧光-平行因子分析结果显示,堆肥DOM及其MW组分主要由3种类腐殖质(C1—C3)和1种类蛋白质(C4)构成。其中,MRC和RSC中的HMW组分均以长波类腐殖酸(C3)组成为主,其含量分别占HMW组分总荧光强度的34%和85%;而两类堆肥中MMW和LMW组分则以类富里酸(C1,41%~53%)和短波类腐殖酸(C2,25%~36%)组成为主。红外光谱(FTIR)结果表明,堆肥DOM中HMW组分含有更多的疏水性苯环结构,而MMW和LMW组分则具有较多的亲水性含氧官能团(如羰基、羧基等)。研究结果促进了对堆肥DOM化学组成和分子结构的认识,为进一步评价堆肥腐熟和稳定化程度及其环境行为等提供了重要的数据参考。

不同有机酸对石灰性土壤磷的活化效应及机理

【目的】添加低分子量有机酸是活化土壤难溶性磷有效途径。比较研究几种低分子量有机酸及其组合对土壤磷的活化性能,为土壤磷的高效利用提供依据。【方法】低磷和高磷石灰性土壤选自新疆石河子,设置5个低分子有机酸添加处理:草酸、柠檬酸、黄腐酸、柠檬酸+草酸、草酸+柠檬酸+黄腐酸处理,和一个0.01mmol/L KCl对照。采用吸附平衡实验法测定土壤磷的吸附量;采用土壤吸附动力学实验法测定土壤磷的解吸动力学。采用常规和灭菌土壤培养方法,通过连续浸提法研究低分子有机酸及其组合对磷组分动态转化的影响和pH对磷的活化效应。【结果】Langmuir与Elovich模型均可较好地拟合土壤对磷的吸附热力学(R^(2)=0.852~0.994)与吸附动力学过程(R^(2)=0.882~0.975)。低磷土壤的最大吸附量(Q_(max))、最大缓冲容量(MBC)、吸附力常数(K_L)和吸附速率(b)均高于高磷土壤,表明低磷土壤对磷的吸附更强。低分子量有机酸添加均降低了Q_(max)、MBC和b。草酸对Q_(max)和MBC的降幅最大,低磷土壤降幅分别为28.5%和74.9%,高磷土壤分别为14.7%和73.3%。柠檬酸对低磷土壤的b值降幅最大(80.9%),草酸对高磷土壤的b值降幅最大(22.0%)。与CK相比,草酸添加显著提高了Olsen-P含量,草酸+柠檬酸效果次之,黄腐酸对磷的活化效果最差。不灭菌培养条件下,草酸和草酸+柠檬酸处理低磷土壤的Olsen-P含量分别增加了42.6%和18.5%,高磷土壤分别增加了27.3%和1.01%;草酸和草酸+柠檬酸处理的活性磷组分Resin-P在低磷土壤中分别增加了80.9%和77.4%,在高磷土壤中分别增加了79.5%和72.8%;非活性磷组分Di HCl-P在低磷土壤中分别降低了8.87%和5.89%,在高磷土壤中分别降低了8.83%和5.54%;Con HCl-P在低磷土壤中分别降低了25.1%和12.9%,在高磷土壤中分别降低了16.9%和5.30%。柠檬酸处理的Resin-P在低磷和高磷土壤中分别增加了70.2%和79.5%,而NaOH-P则分别降低了14.8%、26.3%,说明草酸、草酸+柠檬酸促进了非活性磷向活性磷组分的转化,柠檬酸则促进了中活性磷向活性磷组分的转化。土壤灭菌培养各处理磷组分含量与不灭菌培养无显著差异,说明微生物对有机酸活化土壤磷的效应无显著影响。不论是否灭菌,土壤Olsen-P含量的增加与pH降低呈负相关,因此致酸效应不是小分子有机酸活化土壤难溶性磷的主要机制。【结论】小分子有机酸通过与磷竞争吸附位点或进行螯合反应活化土壤磷,而不是通过致酸效应或激发磷活化相关的微生物。3种小分子有机酸相比,草酸活化磷的效果最大,其次是柠檬酸、黄腐酸,单一有机酸的活化效果大于有机酸组合。

Study of Volume,Weight and Size of Normal Pancreas,Spleen and Kidney in Adults Autopsies

Aims: 1) To establish the volume, weight and size of a normal pancreas, spleen and kidney in 114 adult male autopsies;2) To investigate the relationship between the volume, weight, and size of the pancreas, spleen, and kidney with body mass index (BMI), body surface area (BSA), age, height, and weight. Methods: The normal pancreas, spleen, and kidney volume, weight, and size retrospectively gathered from 114 forensic autopsy cases between the ages of 25 and 88 years. The pancreas, spleen, and kidney volume, weight, and size were available. The parameters used for statistical correlation were the age, height, body weight, BMI, and BSA of the deceased. Results: The volume, weight, and size of all the organs were shown in correlation with the deceased’s height, body weight, BMI, and BSA but not age. The organ volume, weight, and size showed a better statistical correlation with the BSA, BMI, and body weight than the height. Conclusions: The normal reference ranges for organ volume, weight, and size given in this study can serve as a standard to judge atrophy or hypertrophy of organs in post-mortem diagnosis.

蛋重对雏鸡初生重和器官发育的影响

试验旨在研究不同蛋重对雏鸡初生重和器官发育的影响。选取90枚种鸡蛋按蛋重分为5组,每组18枚:Ⅰ组(59~62 g)、Ⅱ组(62~65 g)、Ⅲ组(65~68 g)、Ⅳ组(68~71 g)、Ⅴ组(71~74 g)进行为期21 d的孵化。出雏后对雏鸡进行称重、采血和屠宰,记录并分析数据。结果表明:①雏鸡初生重与蛋重呈显著正相关;②雏鸡的心脏、肝脏、脾脏、肺脏、肾脏、小肠、肌胃重量与蛋重呈正相关,Ⅴ组的腺胃指数显著低于Ⅰ组(P<0.05),其余器官指数各组间无显著差异(P>0.05);③Ⅴ组雏鸡血清中三酰甘油的含量显著高于Ⅰ、Ⅱ组(P<0.05),Ⅴ组高密度脂蛋白含量显著低于Ⅰ、Ⅱ组(P<0.05),Ⅴ组胆固醇的含量显著高于Ⅰ、Ⅱ、Ⅲ组(P<0.05)。综上,蛋重与雏鸡的健康水平相关,且蛋重较大不利于雏鸡的健康。

Effects of maize root exudates and organic acids on the desorption of phenanthrene from soils

The effects of maize root exudates and low-molecular-weight-organic anions （LMWOAs） on the desorption of phenanthrene from eight artificially contaminated soils were evaluated. A significant negative correlation was observed between the amounts of phenanthrene desorbed and the soil organic carbon （SOC） contents （P 〈 0.01）, and the influences of soil pH and clay content on phenanthrene desorption were insignificant （P 〉 0.1）. Neither maize root exudates nor oxalate and citrate anions influenced desorption of phenanthrene with the addition of NaN3. A faster phenanthrene desorption occurred without the addition of NaN3 in the presence of maize root exudates than oxalate or citrate due to the enhanced degradation by root exudates. Without the addition of NAN3, oxalate or citrate at different concentrations could inhibit phenanthrene desorption to different extents and the inhibiting effect by citrate was more significant than by oxalate. This study leads to the conclusion that maize root exudates can not enhance the desorption under abiotic condition with the addition of NaN3 and can promote the desorption of phenanthrene in soils without the addition of NaN3.