河流致突变致畸致癌有机污染物的控制对策

目前在我国工业发达地区，河流水体中致突变性、致畸性、致癌性有机物污染较为严重，针对这一状况，本文综合国内外关于水体中“三致”有机物的研究，从行政、科技两个方面对河水中致突变致畸致癌有机污染物的控制对策提出合理建议。     

镉致鸡脾淋巴细胞凋亡及对p53mRNA表达的影响

应用吖啶橙/溴化乙锭荧光染色(AO/EB)法、DNA琼脂糖凝胶电泳及半定量RT-PCR法检测了氯化镉在浓度0～30mol/L范围内对体外培养的鸡脾脏淋巴细胞凋亡及对p53mRNA表达的影响.结果表明,浓度为0～30mol/L的镉能引起鸡脾脏淋巴细胞凋亡及干扰p53mRNA的表达,低浓度镉引起的细胞凋亡与p53mRNA的表达密切相关,而高浓度的镉能够导致鸡脾脏淋巴细胞坏死.     

鸡粪热裂解对重金属Mn、Cu、Zn和Cr生物有效性的影响

畜禽粪便直接农用引起的重金属污染是社会普遍关注的问题,探索如何有效降低畜禽粪便重金属生物有效性的技术是急需解决的难题.本文通过分析鸡粪(CM)裂解前后Mn、Cu、Zn和Cr等4种重金属形态分布变化,并采用林地大型盆栽试验研究添加CM和鸡粪炭(CMB)处理对湿地松地上部分重金属吸收状况的影响.结果表明,与CM直接还田相比,添加CMB(400℃)处理降低Mn、Cu和Zn在湿地松地上部分的吸收量和富集系数,而处理之间植株Cr元素的吸收量和富集系数差异不显著. Tessier连续提取结果表明, Mn、Cu和Zn的交换态含量分别由CM的94.8、10.0和34.9 mg·kg~(-1)显著降为CMB的16.6 mg·kg~(-1)、未检测出和1.8 mg·kg~(-1). CM裂解成CMB后, Cr元素残渣态含量显著提高.从元素质量守恒来看, CM制成CMB后Mn、Cu、Zn和Cr损失率分别为29.3%、35.6%、33.5%和3.3%.裂解油中Mn、Cu、Zn和Cr的金属总量分别占CM金属损失量的51.7%、53.0%、32.9%和13.1%. CM裂解成CMB后,91.7%的交换态Mn、几乎100%交换态Cu和97.5%的交换态Zn会随裂解转化为铁锰氧化态、有机结合态和残渣态形式或挥发而降低有效性. 1年盆栽试验结果表明,在CMB处理中,土壤Mn、Cu和Zn交换态含量显著低于CM处理.相关性分析发现,植物体内重金属吸收量与土壤金属有效态含量显著相关,而与总量相关性不明显.由此可见,将鸡粪制成鸡粪炭是一种有效降低Mn、Cu和Zn生物有效性的途径.     

硒,砷联合致畸作用的体外全胚胎培养实验研究

用体外全胚胎培养模型探讨在硒和砷共存环境下，对旋转培养４８ｈ的大鼠胚胎（９．５ｄ）的生长发育和器官形态分化所产生的联合作用。结果表明，硒，砷联合毒性的主效应呈相互相拮抗的（Ｐ＝０．０００１）。除细胞干重指标外，其它反映胚胎生长发育和器官形态分化的各项指标均有明显好转，与正常对照组比较没有显著性差异（Ｐ〈０．０５），砷在高剂量在（３．０μｇ／ｍＬ０，硒（０．５￣２．０μｇ／ｍＬ）对砷的毒性无明显缓解     

Reduced lysine uptake by bean rust haustoria in a resistant reaction

The Science of Nature -     

鸡粪腐解过程中不同溶性腐殖质结合铜的变化

以鸡粪为材料,添加不同比例的铜锌进行腐解试验,研究了腐解过程中不同溶性腐殖质结合态铜(水溶性、氢氧化钠溶性、氢氧化钠-焦磷酸钠混合液溶性)浓度的动态变化、受锌含量的影响及其与有效铜的关系.结果表明,粪肥原样H2O-Cu(水溶性腐殖质结合态铜)占其全铜量的10.97%,在腐解过程中先上升后下降;随着粪肥中添加铜量的增加(1:1、2:1、3:1处理),H2O-Cu占其全铜的比例相应减少了(平均分别占其全铜的比例的7.10%、5.18%和3.74%);H2O-Cu随着腐解时间延长呈增加趋势;在腐解的后期(45、60d),粪肥中锌含量的增加会降低H2O-Cu含量.腐解初期粪肥原样NaOH浸提腐殖质-铜(NaOH-Cu)占其全铜量的70.87%,随腐解进行其比例大幅度下降;NaOH-Cu占其全铜的比例随着加入铜的增大而有所下降,分别为55.59%、46.04%和38.08%,且随着腐解时间延长呈下降趋势;粪肥中锌含量的增加对NaOH-Cu含量变化影响较小.粪肥原样中NaOH-Na4P2O7提取腐殖质结合态铜(NaOH-Na4P2O7-Cu)占其全铜量的24.29%,随腐解过程呈增加趋势,NaOH-Na4P2O7-Cu量随着加入铜量的增加而增加,占其全铜比例的15%～25%;粪肥中锌含量增加对NaOH-Na4P2O7-Cu有促进作用.粪肥添加铜锌后,3种浸提剂提取的可溶性腐殖质结合态铜有55%～80%分配在NaOH的溶液中,10%～30%分配在NaOH-Na4P2O7碱性混合液中,0～10%在水溶液中;随加入铜含量和锌含量的增加,NaOH-Na4P2O7-Cu平均分配比(占3种町浸提性腐殖质-Cu的比例)增加,NaOH-Cu和H2O-Cu的分配比减少.相关性分析结果表明:H2O-Cu、NaOH-Cu和NaOH-Na4P2O7-Cu之间显著正相关,它们与有效铜之间呈显著正相关关系(p<0.01).     

Biosorption of phenol by chicken feathers

This work aimed at exploring the potential use of chicken feathers as a biosorbent for the removal of phenol from aqueous solutions. Batch kinetics and isotherm studies were performed to evaluate the effects of process parameters such as pH, temperature, initial phenol concentration, and sorbent concentration. Complete adsorption of phenol was noticed under certain process conditions. The adsorption of phenol increased with increasing initial phenol concentration, solution pH, temperature, and sorbent concentration. The adsorption equilibrium was well represented by the Freundlich and Langmuir adsorption isotherm models. The thermodynamic parameters obtained by means of the Langmuir model showed that the adsorption process was endothermic.     

不同发酵方式对鸡粪重金属及有机质影响

以鸡粪和稻草秸秆为原料,研究了一次堆肥发酵（包括液体菌剂发酵,L;固体菌剂发酵,S;高温酵素发酵,E）,以及连续二次堆肥发酵（高温酵素发酵+液体菌剂发酵,EL;高温酵素发酵+固体菌剂发酵,ES）下有机肥中重金属含量和形态分布规律、理化性质以及有机质变化特征.结果表明,与堆肥前相比,堆肥后鸡粪有机肥pH值显著增加（P < 0.05）,而EC值和含水率均显著减少（P < 0.05）.小白菜种子发芽率由堆肥前的高达58.1%下降到堆肥后小于20%.堆肥后重金属由可溶态向难降解残渣态转化,有机肥中Cu、Zn、Cr、Cd、Pb和As钝化率分别达到27.2%~69.3%、17.1%~50.7%、24.0%~68.7%、16.9%~46.3%、33.1%~54.3%和0.4%~29.5%.腐殖物质和胡敏酸含量显著增加（P < 0.05）,胡敏酸/富里酸（HA/FA）比值均上升.堆肥中多糖类和脂肪族化合物含量均有所增加,但香族类化合物有所降低.从重金属钝化率、有机肥腐熟度等有机肥无害化指标来看,连续二次发酵效果优于一次发酵,其中EL效果最佳.     

基于RF-LSTM的鸡舍恶臭气体预测研究

以鸡舍氨气为研究对象,对鸡舍氨气预测模型进行了研究.首先,利用随机森林算法（RF）对影响鸡舍氨气浓度的环境变量进行重要性排序,选取温度、湿度、光照、气象温度、降雨量作为模型的输入变量;在此基础上,构建了基于长短时记忆神经网络（LSTM）的鸡舍氨气浓度预测模型,并将提出的预测模型应用于江苏省宜兴市某养鸡场的氨气浓度预测中,并与LSTM模型、RF-Elman模型和RF-BP模型进行了对比实验,结果表明,基于RF-LSTM模型的预测效果最好,其平均绝对误差（MAE）、平均绝对百分误差（MAPE）和均方根误差（RMSE）分别为0.9183、4.9637%和1.4262;同时,为了验证该模型的性能,本文还实现了不同时间尺度的鸡舍氨气浓度预测,提前2h、3h、4h、5h氨气预测的平均绝对误差（MAE）分别为1.6218、2.1991、2.8553和3.0677.本文提出的预测模型提高了鸡舍氨气浓度的预测精度,可为减少鸡舍恶臭气体排放提供科学依据.     

Perturbations in the antioxidant metabolism during Newcastle disease virus (NDV) infection in chicken

The aim of the present study was to investigate the effect of vitamin E on pro/anti-oxidant status in the liver, brain and heart of Newcastle disease virus (NDV) infected chickens. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and the levels of reduced glutathione and malonaldehyde were estimated in selected tissues of uninfected, NDV-infected and NDV + vit. E-treated chickens. A significant increase in MDA levels in brain and liver (p < 0.05) was observed in NDV-infected chickens when compared to controls. The activities of SOD, CAT, GPx, GR, GST and levels of GSH were significantly (p < 0.05) decreased in brain and liver of NDV-infected chickens over controls. On the other hand, a significant decreased MDA levels and enhanced antioxidant enzyme activity levels were observed in NDV + vit. E-treated animals compared to NDV-infected chickens. Histopathological studies revealed that liver of NDV infected chicken shows focal coagulation and infiltration of hepatocytes, whereas neuronal necrosis and degeneration of Purkinje cells were observed in brain and moderate infiltration of inflammatory cells was observed in heart. However such histological alterations were not observed in NDV + vit. E-treated animals. The results of the present study, thus demonstrated that antioxidant defense mechanism is impaired after the induction of NDV, suggesting its critical role in cellular injury in brain and liver. Further, the results also suggest that vitamin E treatment will ameliorate the antioxidant status in the infected animals. The findings could be beneficial to understand the role of oxidative stress in the pathogenesis of NDV and therapeutic interventions of antioxidants.     

镉对鸡垂体Fas和caspase-3 mRNA表达的影响

探讨氯化镉(CdCl2)诱导鸡脑垂体细胞凋亡的发生情况及对凋亡相关基因Fas和caspase-3表达的影响.选择健康50日龄海兰白蛋鸡90只,分为3组,每组30只,以CdCl2含量为0、140、210 mg·kg -1的拌料饲喂,分别于染毒20d、40d和60d时取垂体,用原位末端标记(Tunel)和RT-PCR方法检测细胞凋亡和基因表达情况.实验结果表明,CdCl2作用后可致鸡腺垂体细胞呈现明显的凋亡征象,并可诱导垂体细胞Fas和caspase-3 mRNA表达的增加;在整个试验期的各个时间点2个剂量组的凋亡率和基因表达量与对照组相比差异显著(p<0.01),且随着染镉时间的延长,低剂量组的凋亡率以及Fas、caspase-3 mRNA表达增加较明显.这表明,一定剂量的CdCl2可诱导鸡垂体细胞凋亡,在此过程中Fas和caspase-3 mRNA表达呈现出与凋亡较为一致的趋势.     

Beneficial reuse of chicken feathers in removal of heavy metals from wastewater

Natural and chemically treated chicken feathers (CF) were tested for their ability, as adsorbents, to remove copper and zinc from wastewater. Alkaline solutions of 0.2 N NaOH were found to be the best for the sorption process and a 0.6 wt% solution of dodecyl sulfate, as anionic surfactant, also gave best adsorption results. Treatment of CF with alkaline solutions adsorb more metal ions than those treated with the anionic surfactant followed by the untreated CF. Generally, the kinetics of the removal process by all tested sorbents was fast. The Freundlich isotherm model was found to represent the equilibrium results, of all adsorbents toward copper and zinc, reasonably well.     

生物炭介导鸡粪厌氧消化性能研究

为探究生物炭介导的鸡粪厌氧消化产甲烷的较优添加比例,在发酵温度[（35±1）℃]、接种率30%的条件下,进行了以鸡粪为底物,生物炭为外源添加剂的厌氧消化试验,研究生物炭不同添加量（20%、15%、10%、5%和不添加）对鸡粪厌氧消化产气特性的影响,确定了生物炭介导的鸡粪厌氧消化的较优添加比例;同时,用扫描电子显微镜对厌氧消化前后生物炭颗粒和附着在生物炭颗粒上的微生物进行了观察.结果表明：生物炭的添加提高了鸡粪单位VS产甲烷量,添加20%、15%、10%和5%生物炭的处理鸡粪VS产甲烷量分别为223mL/g、228mL/g、230mL/g和281mL/g,均高于对照组的202mL/g;添加生物炭提高了产气中的甲烷含量,降低了二氧化碳和硫化氢含量,提高了沼气品质;电镜扫描结果表明,厌氧消化后生物炭表面及内部附着了大量厌氧微生物,主要为杆菌、微粒菌和球菌;本研究中,生物炭介导鸡粪厌氧消化最优的添加比例约为5%.     

鸡粪与麦秆混合厌氧发酵环境中各因子响应关系研究

为了探究发酵过程中各因子之间的相互响应关系,以鸡粪和麦秆为发酵原料,利用Canoco4.5软件对鸡粪/麦秆不同比例混合发酵条件下不同发酵阶段内各因子进行分析,以阐明各发酵阶段内因子间的相互影响关系.结果表明:当鸡粪/麦秆以5∶5的比例混合时,能获得最佳单位甲烷产量(90.56 m L·g-1,以VS计).在整个发酵过程中甲烷产气速率表现为先升高再降低的趋势,将其根据产气速率的大小划分为3个阶段,分别为第Ⅰ阶段(预备期)、第Ⅱ阶段(高峰期)、第Ⅲ阶段(消退期).不同发酵阶段影响单位甲烷产量的主效因子有一定的差异性,其中,第Ⅱ阶段的主效因子为发酵基质的C/N,第Ⅲ阶段为p H值.各发酵阶段因子间相关性各异,第一阶段因子间相关性最强,此后相关性逐渐降低.因此,针对不同阶段各主效因子分别进行控制,能够有效提高发酵效率.     

Biological treatment of chicken feather waste for improved biogas production

A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers (4%, W/V) were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm³/kg dry feathers (i.e., 0.4 Nm³/kg volatile solids of feathers), corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre-hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm³/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm³ CH₄/kg dry feathers as maximum yield.     

电子拆解区家禽中溴代阻燃剂的污染特征

对某电子废物拆解区散养草鸡进行了12种多溴联苯醚(PBDEs)和十溴二苯乙烷(DBDPE)的污染水平分析.结果显示,草鸡中PBDEs和DBDPE主要通过土壤途径摄入,各个组织中PBDEs均被检出,肾脏中PBDEs含量最高(2071 ng·g~(-1),以脂重计),肝脏中PBDEs平均含量(550ng·g~(-1),以脂重计)远高于肌肉组织(131 ng·g~(-1)(腿肉)和76 ng·g~(-1)(胸肉),以脂重计),DBDPE主要在肾脏和卵组织中检出.同时,本文对电子拆解区居民通过食用草鸡摄入溴代阻燃剂(BFRs)的健康风险进行了初步评价.结果显示,尽管拆解区居民通过食用草鸡暴露PBDEs和DBDPE的风险处于可接受水平,但综合饮用水、大气呼吸和灰尘摄入等其他暴露途径,BFRs健康风险仍不容忽视.     

鸡粪中3种四环素类抗生素在棕壤中的动态变化及原因分析

采用室内模拟培养试验,研究了鸡粪中3种四环素类抗生素在棕壤中含量的动态变化规律及消解途径.结果表明鸡粪中所含的3种四环素类抗生素在棕壤中的含量均表现为前期迅速下降,中后期逐渐平稳的规律,但不同种类和用量处理的变化速率和降解率有显著差异(p＜0.05);180 d时,3种抗生素在棕壤中的降解率为金霉素＞土霉索＞四环素,相...