污泥堆肥混合基质对香彩雀生长开花的影响及植物适应性评价

采用盆栽试验,研究了以城市污泥堆肥为主要原料的基质对观花植物香彩雀(Angelonia salicariifolia Humb.)生长和开花特性的影响,并采用熵权系数与TOPSIS集成评价法综合评价了不同基质对香彩雀的生长适应性。结果表明,经过60 d高温好氧堆制的污泥堆肥,以不同体积比与泥炭、河沙混配成的栽培基质容重和EC值比研究区的林地赤红壤低,pH值和养分含量更高。污泥堆肥混合基质栽培的香彩雀营养生长和生殖生长均优于土壤栽培,其中株高比后者增加29%~61%,分枝数增加27%~67%,鲜重增加17%~88%,干重增加4%~50%,开花时间提前2~16 d,花朵数增加49%~220%,花期延长8~22 d,花朵畸形率降低1%~5%,对氮、磷、钾的吸收能力显著提高。试验中各种污泥堆肥混合基质均适合香彩雀生长,熵权系数与TOPSIS集成评价结果显示,在所研究的污泥堆肥基质中,污泥堆肥:泥炭:河沙体积比为5∶3∶2的基质植物适应性最强,纯污泥堆肥植物适应性相对较差,但优于土壤。将污泥堆肥作为基质主要成分用于花卉生产,既可提高花卉质量,降低成本,又能消耗大量污泥,是城市污泥资源化处置和利用的重要方向。     

餐厨垃圾和市政污泥配料比对厌氧产甲烷特性及微生物多样性的影响

在(38±0.5)℃的温度下,研究不同配料比对餐厨垃圾和市政污泥混合厌氧消化过程中系统参数及微生物群落多样性的影响,设定餐厨垃圾和市政污泥的挥发性固体的质量比为1∶0、0∶1、1∶1、1∶2和2∶1,并采用高通量测序技术分析厌氧消化过程中微生物组成的多样性。结果表明:质量比为1∶1的体系混合厌氧消化时,产甲烷效果最佳,单位质量的挥发性固体含量的产甲烷量可达到232.86 L/kg,挥发性固体含量的去除率达46.09%。各个混合比例体系中的优势物种为拟杆菌门(Bacteroidetes)和甲烷八叠球菌属(Methanosarcina)。在餐厨垃圾中添加市政污泥混合厌氧消化能够提高微生物群落的多样性,促进菌种间的协同作用,进而提升产气效率。     

城市污泥好氧堆肥过程中积温规律的探讨

对城市污泥好氧堆肥稳定化过程的温热条件进行了探讨 ,将物候学中的积温概念应用于堆肥稳定化 (腐熟 )过程。它同时兼顾到堆肥过程中的温度强度和持续时间两个参数。对于采用的强制通风静态垛堆肥工艺 ( CTB自动控制堆肥工艺 ) ,建议以 1 5℃作为生物学零度 ,积温指标为 1 0 0 0 0℃· h左右。堆肥原料的性质、堆肥工艺、微生物种群、生物学零度、外界环境等因素可能会对积温产生一定影响     

沼渣与污泥混合高温堆肥效果及氮素控制

以锯木屑为调理剂,以Mg(OH)2与H3PO4的混合液为高温堆肥过程中的氮素抑制剂,研究沼渣与啤酒厂污泥混合堆肥效果。结果表明:混合物经好氧发酵处理后,均达到腐熟。添加氮素固定剂处理和对照处理的最高温度都可达65℃以上,在堆肥过程中添加氮素固定剂处理可提高堆体中有机物质的转化速率,对氮素的固定率达18%以上,添加固氮剂处理的堆肥结束后P元素增加了51%,堆肥品质得到了大幅度提高。堆肥过程中的物料的种子发芽指数不断提高,达到0.9;添加固氮剂的处理堆肥的种子发芽指数为1.0,明显高于对照。可见采用高温堆肥和氮素固定技术可有效地实现沼渣及啤酒厂污泥的混合资源化,该研究为后期沼渣和啤酒厂污泥堆肥的规模化应用提供了技术参数。     

城市污泥与园林废弃物堆肥的混合施用对高羊茅萌发与生长的影响

以北京市城市污泥与园林废弃物为研究对象,采用盆栽方法,将污泥产品与园林废弃物堆肥按不同体积配比(1∶0、1∶3、1∶1和0∶1)混合,设置不同混合物施加量(0%、25%、50%、75%和100%混合物),比较其对高羊茅(Festuca arundinacea L.)的发芽以及生长的影响。结果表明:混合物添加对早期发芽率有负面影响,发芽率最高值出现在污泥与堆肥1∶1的25%混合物施加处理中;在整个观测周期内,加入混合物后株高均显著(P0.05)高于对照,且在后期表现更加明显;单株地上部生物量随着时间的延长各处理均呈现显著增加的趋势,而除了纯污泥处理外,随着施用量的增加,单株地上生物量均呈现降低的趋势;累积地上生物量和地下生物量在各处理下均显著高于对照,最大值出现在污泥与堆肥1∶1的25%混合物施加处理中;污泥与园林废弃物堆肥以不同比例混合后,比对照和仅园林废弃物堆肥对高羊茅的生长影响更明显,但混合物施用量较低时起促进作用,较高时会产生一定的抑制作用,且当两者的配比为1∶1的低施用量条件下高羊茅的生长指标最高。     

城市污泥资源化利用研究

城市污水污泥产量巨大且成分复杂 ,如何对它进行合理利用已越来越受人们关注。文章系统地综述了我国城市污泥处置与利用的现状和趋势 ,并重点讨论了污泥土地利用的可行性以及我国近年来的研究进展。认为将污泥进行稳定化、无害化、资源化处理并作为有机肥料或土壤改良剂等进行资源化利用是符合我国国情的 ,并将成为我国污泥处置与利用的一种有效途径     

基于热水解的高效污泥厌氧消化技术研究进展

污水处理厂产生的大量剩余污泥,是目前困扰市政工程的主要问题之一,对其进行减量化、稳定化、无害化和资源化是污泥处理处置的核心任务。厌氧消化技术是目前最广泛使用的污泥处理工艺之一,但厌氧消化技术受到污泥低水解速率的制约。基于热水解的高效污泥厌氧消化技术不仅打破传统厌氧消化的水解限速,还在改善污泥流变特性和化学特性、提高污泥厌氧消化效率和新兴污染物的去除等方面有着明显的优势。综述了热水解预处理对污泥特性和对系统中新兴污染物去除特性的影响,总结了目前的研究成果并展望了发展前景,指出工艺运行条件的进一步优化和经济可行性的系统评价是其推广使用的重要支撑。     

污泥与园林废弃物混合堆肥对波斯菊生长及重金属积累的影响

随着城镇人口增加和城市化的快速发展,每天产生大量的污泥和园林废弃物,而厌氧消化的污泥与园林废弃物的混合堆肥产品应用于林地土壤改良,是城市废弃物循环利用的一种经济有效的方式。本研究在北京平原造林区开展试验,探讨混合堆肥对波斯菊的生长及对重金属元素吸收的影响。结果表明:施用堆肥对土壤全氮和有机质含量无显著影响; Cu、Zn、Cd三种重金属元素在土壤中主要以残渣态的形态存在;施用堆肥提高了土壤Cu、Zn含量,但Zn总量未超过土壤环境质量标准(GB 15618—2018)中的土壤污染风险筛选值300 mg·kg-1,Cu在施肥量较高时超过土壤污染风险筛选值100 mg·kg-1;土壤背景值中Cd含量已经高于土壤污染风险管制值4.0 mg·kg-1,施用堆肥对Cd含量的影响无明显规律;波斯菊株高、生物量和花数均随着堆肥施用量的增加而增加;波斯菊对重金属元素的富集性表现为CuCdZn。本研究表明,北京平原造林区的人工林生态系统可以忍受一定浓度的污泥和园林废弃物混合堆肥,并利用其中的营养物质,提高土壤肥力,促进植物生长。     

城市污泥堆肥对栽培基质保水能力和有效关效养分的影响

盆栽试验表明,城市污泥堆肥不仅可以明显提高栽培基质的有效氮、磷含量,而且可以增强栽培基质的保水性能和植物的抗旱能力,但是栽培基质的萎焉点也随着其用量的增加而增高,因此,从保证植物水分供应的角度考虑,虽然可以大量地使用城市污泥堆肥,但是其用量并不是越多越好;当用量超过75％时,继续增加城市污泥堆肥的比例,则植物的吸水能力反而会略有下降,从养分供应和保水性能等角度综合考虑,采用经过堆肥处理的城市污泥作为植物栽培基质,是城市污泥资源化和无害化的可行途径。     

不同微生物菌剂处理对猪粪堆肥中氨挥发的影响

研究不同微生物复合菌剂及添加比例对猪粪与木屑混合(鲜重比为鲜猪粪∶木屑9∶1)堆肥过程中NH₃挥发的影响.结果表明,在堆肥过程中,NH₃挥发主要产生在堆肥前期15 d的升温和高温期,添加3‰的微生物复合菌剂1、2和3对猪粪堆肥中NH₃挥发都有一定的抑制作用,减轻氮素损失与堆肥恶臭,添加5‰复合菌剂1有显著抑制作用（P＜0.05）.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.