Association of DNA methylation/demethylation with the functional outcome of stroke in a hyperinflammatory state

Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effect of DNA methylation on stroke at high levels of inflammation is unclear. In this study, we constructed a hyperinflammatory cerebral ischemia mouse model and investigated the effect of hypomethylation and hypermethylation on the functional outcome. We constructed a mouse model of transient middle cerebral artery occlusion and treated the mice with lipopolysaccharide to induce a hyperinflammatory state. To investigate the effect of DNA methylation on stroke, we used small molecule inhibitors to restrain the function of key DNA methylation and demethylation enzymes. 2,3,5-Triphenyltetrazolium chloride staining, neurological function scores, neurobehavioral tests, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR and western blot assay were used to evaluate the effects after stroke in mice. We assessed changes in the global methylation status by measuring DNA 5-mc and DNA 5-hmc levels in peripheral blood after the use of the inhibitor. In the group treated with the DNA methylation inhibitor, brain tissue 2,3,5-triphenyltetrazolium chloride staining showed an increase in infarct volume, which was accompanied by a decrease in neurological scores and worsening of neurobehavioral performance. The levels of inflammatory factors interleukin 6 and interleukin-1 beta in ischemic brain tissue and plasma were elevated, indicating increased inflammation. Related inflammatory pathway exploration showed significant overactivation of nuclear factor kappa B. These results suggested that inhibiting DNA methylation led to poor functional outcome in mice with high inflammation following stroke. Further, the effects were reversed by inhibition of DNA demethylation. Our findings suggest that DNA methylation regulates the inflammatory response in stroke and has an important role in the functional outcome of hyperinflammatory stroke.

Punicalagin prevents obesity-related cardiac dysfunction through promoting DNA demethylation in mice

The aim of this study was to investigate whether punicalagin(PU)could prevent obesity-related cardiac dysfunction by promoting DNA demethy lation,and to explore its possible mechanism.C57BL/6J mice were fed with standard diet,high-fat diet(HFD),HFD supplemented with resveratrol,low-dose PU(LPU)and high-dose PU(HPU)for 8 weeks.Compared with HFD group,body weight was significantly lower in PU treatment groups,number of cardionwocytes and the protein level of myosin heavy chain 7B were significantly higher in PU treatment groups.Levels of 5-hydroxymethylcytosine and 5-formylcytosine were significantly lower in HFD group than in other groups.Compared with the HFD group,the protein level of ten-eleven translocation enzyme(TET)2 was significantly higher in PU treatment groups,p-AMP-activated protein kinase(AMPK)was significantly higher in LPU group.Levels of total antioxidant capacity and the protein levels of complexesⅡ/Ⅲ/Ⅴ,oxoglutarate dehydrogenase,succinate dehydrogenase B and fumarate hdrolase were significantly lower in HFD group than PU treatment group.The ratio of(succinic acid+fumaric acid)/a-ketoglutarate was significantly higher in HFD group than other groups.In conclusion,PU up-regulated TETs enzyme activities and TET2 protein stability through alleviating mitochondrial dysfunction and activating AMPK,so as to promote DNA demethylation,thus preventing obesity-related cardiac dysfunction.

Observation on the Clinical Effect of Applying Venetoclax Combined with Demethylation Drug Therapy in Patients with Acute Myeloid Leukemia

Objective: To investigate the therapeutic effect of applying venetoclax combined with demethylating drugs in treating patients with acute myeloid leukemia (AML). Methods: Eighty cases of AML patients treated with venetoclax combined with demethylating drugs in our hospital were selected from March 2021 to March 2024, including 40 cases of primary treatment patients and 40 cases of relapsed and refractory patients. The efficacy and safety of the combined drug therapy was analyzed. Results: The primary treatment group was presented with a complete remission (CR) rate of 40.5%, partial remission (PR) rate of 47.50%, no response (NR) rate of 12.50%, and a remission rate of 87.50%. The relapsed- refractory group was presented with a CR rate of 37.50%, PR rate of 42.50%, NR rate of 17.50%, and a remission rate of 87.50%. There was no statistical significance between the groups (P > 0.05). The hematological adverse reactions of the combined treatment for AML were leukopenia and the non-hematological adverse reactions were mainly infections, with an incidence rate of 87.50%. Conclusion: The efficacy of venetoclax combined with demethylating drugs in AML was remarkable and the treatment regimen can be adjusted according to the treatment-resistant response.

Dynamic changes in DNA demethylation in the tree shrew (Tupaia belangeri chinensis) brain during postnatal development and aging

Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5- hydroxymethylcytosine （5hmC） ten-eleven transtocation （TET） enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews （Tupaia belangeri chinensis）. The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.

Impact of GFRA1 gene reactivation by DNA demethylation on prognosis of patients with metastatic colon cancer

BACKGROUND The expression of the membrane receptor protein GFRA1 is frequently upregulated in many cancers,which can promote cancer development by activating the classic RET-RAS-ERK and RET-RAS-PI3K-AKT pathways.Several therapeutic anti-GFRA1 antibody-drug conjugates are under development.Demethylation(or hypomethylation)of GFRA1 CpG islands(dmGFRA1)is associated with increased gene expression and metastasis risk of gastric cancer.However,it is unknown whether dmGFRA1 affects the metastasis of other cancers,including colon cancer(CC).AIM To study whether dmGFRA1 is a driver for CC metastasis and GFRA1 is a potential therapeutic target.METHODS CC and paired surgical margin tissue samples from 144 inpatients and normal colon mucosal biopsies from 21 noncancer patients were included in this study.The methylation status of GFRA1 islands was determined by MethyLight and denaturing high-performance liquid chromatography and bisulfite-sequencing.Kaplan-Meier analysis was used to explore the effect of dmGFRA1 on the survival of CC patients.Impacts of GFRA1 on CC cell proliferation and migration were evaluated by a battery of biological assays in vitro and in vivo.The phosphorylation of AKT and ERK proteins was examined by Western blot analysis.RESULTS The proportion of dmGFRA1 in CC,surgical margin,and normal colon tissues by MethyLight was 68.4%,73.4%,and 35.9%(median;nonparametric test,P=0.001 and<0.001),respectively.Using the median value of dmGFRA1 peak area proportion as the cutoff,the proportion of dmGFRA1-high samples was much higher in poorly differentiated CC samples than in moderately or welldifferentiated samples(92.3%%vs 55.8%,Chi-square test,P=0.002)and significantly higher in CC samples with distant metastasis than in samples without(77.8%vs 46.0%,P=0.021).The overall survival of patients with dmGFRA1-low CC was significantly longer than that of patients with dmGFRA1-high CC(adjusted hazard ratio=0.49,95%confidence interval:0.24-0.98),especially for 89 CC patients with metastatic CC(adjusted hazard ratio=0.41,95%confidence interval:0.18-0.91).These data were confirmed by the mining results from TCGA datasets.Furthermore,GFRA1 overexpression significantly promoted the proliferation/invasion of RKO and HCT116 cells and the growth of RKO cells in nude mice but did not affect their migration.GFRA1 overexpression markedly increased the phosphorylation levels of AKT and ERK proteins,two key molecules in two classic GFRA1 downstream pathways.CONCLUSION GFRA1 expression is frequently reactivated by DNA demethylation in CC tissues and is significantly associated with a poor prognosis in patients with CC,especially those with metastatic CC.GFRA1 can promote the proliferation/growth of CC cells,probably by the activation of AKT and ERK pathways.GFRA1 might be a therapeutic target for CC patients,especially those with metastatic potential.

DNA methylation and demethylation link the properties of mesenchymal stem cells: Regeneration and immunomodulation

Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial tissue.MSCs have attracted increasingly more attention over the years due to their regenerative capacity and function in immunomodulation.The foundation of tissue regeneration is the potential of cells to differentiate into multiple cell lineages and give rise to multiple tissue types.In addition,the immunoregulatory function of MSCs has provided insights into therapeutic treatments for immune-mediated diseases.DNA methylation and demethylation are important epigenetic mechanisms that have been shown to modulate embryonic stem cell maintenance,proliferation,differentiation and apoptosis by activating or suppressing a number of genes.In most studies,DNA hypermethylation is associated with gene suppression,while hypomethylation or demethylation is associated with gene activation.The dynamic balance of DNA methylation and demethylation is required for normal mammalian development and inhibits the onset of abnormal phenotypes.However,the exact role of DNA methylation and demethylation in MSC-based tissue regeneration and immunomodulation requires further investigation.In this review,we discuss how DNA methylation and demethylation function in multi-lineage cell differentiation and immunomodulation of MSCs based on previously published work.Furthermore,we discuss the implications of the role of DNA methylation and demethylation in MSCs for the treatment of metabolic or immune-related diseases.

Properties of Bark Particleboard Bonded with Demethylated Lignin Adhesives Derived from Leucaena leucocephala Bark

Lignin extraction from bark can maximize the utilization of biomass waste,offer cost-effectiveness,and promote environmental friendliness when employed as an adhesive material in bark particleboard production.Particles of fine(0.2 to 1.0 mm),medium(1.0 to 2.5 mm),and coarse(2.5 to 12.0 mm)sizes,derived from the bark of Leucaena leucocephala,were hot-pressed using a heating plate at 175℃for 7 min to create single-layer particleboards measuring 320 mm×320 mm×10 mm,targeting a density of 700 kg/m^(3).Subsequently,the samples were trimmed and conditioned at 20℃and 65%relative humidity.In this study,we compared bark particleboard bonded with urea formaldehyde(UF)adhesive to fine-sized particleboard bonded with demethylated lignin adhesive.The results indicated that bark particleboards utilizing demethylated lignin and UF adhesives exhibited similar qualities.Coarse particleboard showed differences in modulus of elasticity(MOE)and modulus of rupture(MOR),while medium-sized particles exhibited significant variations in moisture content(MC)and water absorption(WA).Furthermore,the thickness swelling of coarse and medium-sized particles under wet and oven-dried conditions exhibited notable distinctions.Overall,the demethylated lignin adhesive extracted from L.leucocephala bark demonstrated similar quality to UF adhesive,with particle size correlating inversely to the strength of the bark particleboard.

CuCl-catalyzed Oxidative N-Demethylation of Arylamines with tButyl Hydroperoxide

CuCl-catalyzed oxidative N-demethylation of arylamines proceeded in the presence of tert-butyl hydroperoxide. The one-electron transfer route of oxidative N-demethylation competed favorably with the H-atom abstraction route.

Demethoxylation and O-Demethylation of Pseudaconine and Isotalatizidine

Demethoxylation and O-demethylation of the norditerpenoid alkaloids pseudaconine and isolatatizidine were described.

Mechanoresponsive Gene Upregulation by Force Depends on H3K9Demethylation

All living cells in a human body are made of the same DNA molecule but cells in different tissues express different genes and proteins.How the transcription process is controlled and regulated is largely unknown.Specifically,mechanical forces are increasingly recognized to play critical roles in cell and tissue functions.However,what controls force-induced gene transcription is elusive.Recently we have reported that a local surface force transfers from integrins to the cytoskeleton and the link of nucleoskeleton and the cytoskeleton(LINC)into the nucleus and deforms chromatin directly to induce rapid activation of transgene DHFR.Here we show that endogenous mechanoresponsive genes egr-1 and Cav1 are rapidly upregulated and their upregulation depends on stress angles relative to the cell long axis,suggesting direct impact of these genes by force.Demethylation of histone 3 at lysine 9(H3K9)trimethylation(H3K9me3)at nuclear interiors(euchromatin)is necessary for force-induced transcription upregulation.Our findings suggest that force-rapid upregulation of mechanoresponsive genes by force depends on H3K9me3 demethylation.

经“O”点穿刺与传统单侧入路治疗L_(5)椎体骨质疏松性压缩性骨折

背景:单侧穿刺入路经皮穿刺球囊扩张椎体后凸成形治疗骨质疏松性椎体压缩骨折优于双侧穿刺入路,由于L_(5)特殊解剖形态和位置特殊,传统单侧穿刺入路治疗L_(5)椎体骨质疏松性椎体压缩骨折适用性差,因此提出“O”点穿刺入路来解决该问题。目的:比较经横突基底部-椎弓根后上部-关节突外侧交点(“O”点)入路与传统单侧入路经皮穿刺球囊扩张椎体后凸成形治疗L_(5)椎体骨质疏松性压缩骨折的疗效差异。方法:回顾性分析西南医科大学附属医院2020年1月至2022年12月收治的54例L_(5)椎体骨质疏松性压缩骨折行经“O”点入路或传统经皮穿刺球囊扩张椎体后凸成形治疗的患者,根据手术方式分为2组,“O”点入路组(A组)29例,传统入路组(B组)25例。术前在X射线正位片测量A组“O”点与髂棘位置及穿刺角度;比较两组术前与术后第2天、末次随访的局部Cobb角、椎体前缘、中部高度及骨水泥分布情况;术前、术后第2天及末次随访采用疼痛目测类比评分、Oswestry功能障碍指数评估患者疼痛缓解情况与日常生活能力,记录手术相关并发症。结果与结论:①A组手术时间、术中透视次数均少于B组,差异有显著性意义(P<0.05);两组术中出血量及骨水泥注射量差异无显著性意义;②两组患者术后第2天及末次随访疼痛目测类比评分、Oswestry功能障碍指数较术前明显降低,且A组降低比B组更明显(P<0.05);③“O”点位于双侧髂棘最高点连线之下平均距离1.23 cm;“O”点到髂棘平均横向距离2.89 cm;④两组患者末次随访Cobb角较术前明显改善(P<0.05),但两组间比较差异无显著性意义(P>0.05);⑤术后骨水泥分布,A组分布良好占97%(28/29),B组分布良好占88%(22/25),A组明显优于B组(P<0.05);⑥提示经“O”点穿刺入路与传统入路经皮穿刺球囊扩张椎体后凸成形治疗L_(5)椎体骨质疏松性压缩骨折疗效满意,但“O”点穿刺入路经皮穿刺球囊扩张椎体后凸成形治疗骨水泥分布更满意,还可避免高髂棘对L_(5)椎体穿刺入路的影响。

O臂导航在椎弓根发育性狭窄胸腰椎骨折中的精准应用

背景:传统透视辅助治疗椎弓根发育性狭窄的胸腰椎骨折时精准置钉存在困难,O臂导航辅助系统在普通的椎弓根置钉中精准性更高,但关于O臂导航辅助置钉在椎弓根发育狭窄胸腰椎骨折中的应用国内外鲜有报道。目的:探讨O臂导航辅助经皮椎弓根置钉在椎弓根发育性狭窄的胸腰椎骨折患者中的准确性。方法:回顾性分析2021年1月至2023年3月中部战区总医院骨科行经皮椎弓根螺钉内固定的53例椎弓根发育性狭窄的胸腰椎骨折患者,其中出现发育性狭窄的椎弓根共208个(患者多处椎弓根发育狭窄的分开统计)。依据手术方式分为2组:O臂导航组98个椎弓根,C臂透视组110个椎弓根。比较两组患者解剖学穿孔评分、功能性穿孔评分、实际与预期钉道的水平面、矢状面角度差等术后影像资料。结果与结论:①两组患者在椎弓根最窄宽度(pow)上没有显著差异(P>0.05);两组患者在不同程度的狭窄分组中(轻度狭窄组:6 mm≤pow<7 mm,中度狭窄组:5 mm≤pow<6 mm,重度狭窄组:pow<5 mm)的比例也没有显著差异(P>0.05);②O臂组在解剖学穿孔和功能性穿孔上的整体等级及评分低于C臂组,差异有显著性意义(P<0.001);在实际钉道与预期钉道夹角差方面,O臂组实际与预期钉道的角度偏差更小,差异有显著性意义(P<0.05);③在轻度及中度狭窄组中,O臂组在解剖学穿孔、功能性穿孔以及实际钉道与预期钉道夹角差方面表现出明显的优势,差异有显著性意义(P<0.001);④O臂组在解剖学穿孔和功能性穿孔方面整体表现更佳,尤其在T12-L2节段,其优势更加显著;此外,O臂组在各节段的实际钉道与预期钉道夹角差方面均优于C臂组;⑤因此采用O臂导航辅助经皮置钉治疗椎弓根发育性狭窄的胸腰椎骨折,经皮置钉精准度及安全性更高。

Cornel iridoid glycoside inhibits PP2Ac demethylation by regulationg PME-1

OBJECTIVE PP2Ac demethyl⁃ation is regulated by LCMT(a specific leucine carboxyl methyltransferase catalyzing methyla⁃tion of PP2A)and PME(a specific methylester⁃ase catalyzing demethylation of PP2A.This study was to investigate the mechanism of Cor⁃nel iridoid glycoside(CIG)on PP2A catalytic sub⁃unit C(PP2Ac).METHODS Recombined lentivi⁃rus vector was used to deliver PME-1 genetic materials into N2a cells or transfected LCMT-1 siRNA into N2a cells to block the expression of LCMT-1.Twenty-four hours later,cells were rinsed twice with cold PBS(pH 7.4)and CIG at different concentrations(50,100 and 200 g·L^(-1),respectively)were added for 24 h.Western blotting was used to PP2Ac,demethylaion/methylation PP2Ac,LCMT-1 and PME-1.The ac⁃tivity of PP2A was detected by a biochemical as⁃say.RESULTS①Lentivirus transferred PME-1 was expressed at high level in the N2a cells after transduction.Correspondingly,the demethylation of PP2Ac was increasing and PP2A activity was decreasing after transduction.Treatment with CIG for 24 h reversed the increase of PME-1 and demethylation of PP2Ac without influencing LCMT-1 expression.PP2A activity was also sig⁃nificantly enhanced in CIG treatment group,compared with the cells after PME-1 transduc⁃tion.②LCMT-1 siRNA significantly decreased LCMT-1 expression.CIG did not affect LCMT-1expression.however,demethylation of PP2Ac is increased in siRNA-transfected cells and CIG could reversed the high demethylation of PP2Ac and PP2A activity.CONLUSION CIG increases methylation of PP2A subunit C by inhibiting PME-1.

Demethylation of FANCF gene may be a potential treatment through inhibiting the proliferation of cervical cancer

Objective: The aim of the study was to explore the effect of demethylating agent 5-Aza-2'-deoxycytidine (5-ADC) on expression of Fanconi anemia complementation group F (FANCF) gene and the proliferation of cervical cancer cells, to observe cell's sensitivity to chemotherapeutic drug taxol, and to explore the antitumor effect of 5-ADC as well as the new treatment of cervical cancer. Methods: Cervical cancer cell lines SiHa (FANCF gene full-methylated) and Hela (unmethylated) were treated with 5-ADC. We used the methylation-specific PCR (MSP), reverse transcription-polymerase chain reaction (RT-PCR) and Western blot to detect the FANCF methylation, mRNA and protein respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect the proliferation of cells. The cytotoxicity of taxol was measured by flow cytometer. The nude mice bearing SiHa was used to observe the effect of 5-ADC in vivo. Results: Inhibition of DNA promoter methylation by 5-ADC reactivated the expression of FANCF mRNA and protein in SiHa cells, consistent with decreased growth speed and increased taxol resistance. These results were proven in experiments in vivo. Conclusion: The 5-ADC probably become a potential treatment drug through inhibiting the proliferation of cervical cancer cells in taxol-resistant patients.

A Novel Oxidative N-Demethylation of 12-Membered Macrolide with Lead Tetraacetate

Reaction of 12-membered macrolide 1 with lead tetraacetate in dichloromethane afforded an unexpected, novel oxidative N-demethyl product 3.

（±）－Demethyl Salvicanol的首次全合成研究

（±）－ＤｅｍｅｔｈｙｌＳａｌｖｉｃａｎｏｌ的首次全合成研究王学超，潘鑫复，崔育新，陈耀祖（兰州大学化学系，应用有机化学国家重点实验室，兰州，７３００００）关键词ＤｅｍｅｔｈｙｌＳａｌｖｉｃａｎｏｌ，全合成，选择性还原，锌促偶联反应９（１０→２０）重...

胶东盘子涧金矿床成矿流体特征--来自包裹体、H-O同位素证据

盘子涧金矿床地处华北板块胶辽隆起区,栖霞—蓬莱金成矿带上。金矿的形成主要与区内控矿断裂——盘子涧断裂和中生代岩浆岩有关。为研究该矿床成矿流体性质及演化,并控讨矿床成因,对该矿床不同阶段的包裹体进行岩相学、显微测温、包裹体激光拉曼及H—O同位素分析研究。盘子涧金矿床成矿热液期可划分为4个成矿阶段,从早到晚分别是黄铁矿—石英阶段(Ⅰ阶段)、石英—黄铁矿(绢云母)阶段(Ⅱ阶段)、金—石英—多金属硫化物阶段(Ⅲ阶段)和石英—碳酸盐阶段(Ⅳ阶段)。其中Ⅱ、III阶段为主成矿阶段。不同成矿阶段的流体包裹体有3种类型,分别是富液气液两相盐水包裹体、含CO_(2)三相包裹体和纯液相包裹体。显微测温结果显示,成矿流体的完全均一温度介于142~348℃,主要集中于200~300℃,盐度介于4.44%~10.98%NaCl_(eqv)。石英的δD_(V-SMOW)值为-74.6‰~-68.5‰,δ^(18)O_(V-SMOW)值为+11.65‰~+13.92‰。显示成矿流体为中低温、低盐度的CO_(2)—H_(2)O—NaCl体系,来源于地幔,以岩浆热液为主,并伴有部分大气降水加入。矿床成因类型属石英脉型金矿。

丛枝菌根真菌对褐土玉米氮素吸收和土壤N_(2)O排放的影响

探究不同氮肥水平下丛枝菌根(AM)真菌对褐土玉米土壤N_(2)O排放和氮转化功能基因的影响,为阐明AM真菌在褐土N_(2)O排放中的作用和效应提供理论依据。设置氮肥用量(NⅠ:105 mg/kg;NⅡ:210 mg/kg)、AM真菌(M0:不接种AM真菌;M1:接种根内根孢囊霉(Rhizophagus intraradices);M2:接种摩西斗管囊霉(Funneliformis mosseae);M3:接种Rhizophagus intraradices+Funneliformis mosseae等比例混合)双因素盆栽试验。测定植株地上部全氮含量、土壤铵态氮、硝态氮含量和N_(2)O排放量,采用实时荧光定量聚合酶链式反应(PCR)法分析土壤硝化功能基因(amoA-AOA和amoA-AOB)和反硝化功能基因(nirS、nirK和nosZ)的丰度。结果表明,两种施氮水平下,接种AM真菌均可显著降低土壤N_(2)O排放通量和累积排放量,不同AM真菌处理下N_(2)O累积排放量表现为:M0>M2>M1>M3。相同AM真菌处理的土壤N_(2)O排放通量和累积排放量在NⅡ施氮水平高于NⅠ施氮水平;相同AM真菌处理的玉米菌根侵染率在NⅡ施氮水平低于NⅠ施氮水平。与M0相比,NⅠ条件下M1、M2和M3处理土壤铵态氮含量分别降低24.5%、20.8%和45.3%,硝态氮含量分别降低19.7%、14.9%和30.2%,植株地上部全氮含量分别增加16.3%、35.2%和59.6%;与M0相比,NⅡ条件下M1、M2和M3处理土壤铵态氮含量分别降低20.9%、24.8%和40.0%,硝态氮含量分别降低36.3%、25.6%和45.2%,植株地上部全氮含量分别增加33.2%、43.9%和95.4%。两种施氮水平下,AM真菌可显著降低土壤硝化功能基因(amoA-AOA和amoA-AOB)丰度,增加反硝化功能基因(nirS、nirK和nosZ)丰度。AM真菌与N_(2)O排放通量呈极显著负相关。本盆栽试验条件下,接种AM真菌均可增强两种氮肥用量玉米植株氮素吸收能力,调节硝化、反硝化相关功能基因的丰度,减少土壤N_(2)O气体的排放,且两种AM真菌混合处理的N_(2)O减排效应强于单一AM真菌接种。

理气舒心片中染色剂金胺O检测方法研究

目的:建立理气舒心片中染色剂金胺O的检测方法。方法:色谱柱为OMNI-C_(18)柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.033 mol·L^(-1)磷酸二氢钾溶液(30∶70),流速为1.0 mL·min^(-1),柱温为30℃,检测波长为436 nm。结果:金胺O在0.967~8.703μg·mL^(-1)范围内与峰面积线性关系良好(r=0.9995),加样回收率为95.01%(RSD=2.3%,n=6),精密度、重复性和溶液稳定性良好,方法检出限为0.092μg·g^(-1)。6家生产企业共38批样品中发现有1家企业的5批样品中检出金胺O,含量在1.06~4.63μg·g^(-1)。结论:该方法操作简便、灵敏度好、准确度高,可用于理气舒心片中金胺O的检测。

臭氧氧化+A/O+臭氧氧化工艺在化工园区污水处理厂中的运用

化工园区废水成分复杂,难降解物质多。某化工园区污水处理厂选用分质强化混凝沉淀+臭氧氧化作为预处理工艺,同时采用水解酸化+厌氧好氧(Anaerobic/Oxic,A/O)的二级处理工艺和混凝沉淀+臭氧氧化的深度处理工艺。实际运行结果表明,该组合工艺对化学需氧量(Chemical Oxygen Demand,COD)的平均去除率为85.7%,COD去除效果良好,出水水质优于《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准。