Blood glucose-lowering activity of protocatechuic acid is mediated by inhibiting a-glucosidase

α-Glucosidase inhibitors are effective in controlling postprandial hyperglycemia,which play crucial roles in the management of type 2 diabetes.Protocatechuic acid(PCA)is one of phenolic acids existing not only in various plant foods but also as a major microbial metabolite of dietary anthocyanins in the large colon.The present study investigated the inhibitory mechanism of PCA on a-glucosidase in vitro and examined its effect on postprandial blood glucose levels in vivo.Results from in vitro experiments demonstrated that PCA was a mix-type inhibitor of a-glucosidase.Driven by hydrogen bonds and van der Waals interactions,PCA reversibly bound withα-glucosidase to form a stable a-glucosidase-PCA complex in a spontaneous manner.The computational simulation found that PCA could insert into the active cavity of a-glucosidase and establish hydrogen bonds with catalytic amino acid residues.PCA binding aroused the steric hindrance for substrates to enter active sites and caused the structural changes of interacted catalytic amino acid residues.PCA also exhibited postprandial hypoglycemic capacity in diabetic mice.This study may provide the theoretical basis for the application of PCA as an active ingredient of functional foods in dietary management of diabetes.

Sensitivity of Commercial Enzyme Inhibition Colorimetric Pesticide Residue Rapid Test Kit to a Variety of Pesticides

[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural products.[Methods]The sensitivity of 28 kinds of pesticides was determined by using the commercially available enzyme inhibition colorimetric rapid detection kit with Hendu brand.[Results]There was a significant difference in the sensitivity of the kit to each pesticide,and the kit was more sensitive to dichlorvos among the 28 pesticides tested.The sensitivity to methyl isosalifos,dimethoate,isocarbophos,fenthion and phorate was poor,and the sensitivity to quinalphos was different between 3.0 and 2.5 mL.[Conclusions]The large difference of the sensitivity of the enzyme inhibition-colorimetric rapid detection kit for pesticide residues to different kits is a reason for the false positive and false negative test results of the kit,which needs to be considered by relevant personnel.

Enzyme Inhibition Rate Method for Rapid Detection of Organophosphorus and Carbamate Pesticides in Cowpea

[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, to determine the inhibition rate of extract against enzyme. The influences of different sampiing methods and sampling parts on detection results were compared. [ Results] The positive rate of standard sampling was 18.18% higher than that of non-stand- ard sampling, and the positive rate of samples collected from cowpea tail was 16.67% higher than that collected from other parts. [ Condmions] Enzyme inhibi- tion rate method is suitable for rapid detection of organophosphorus and carbamate pesticides in cowpea.

Study on the Guidance of Platelet Inhibition Rate Detected with Thrombelastogram in Antiplatelet Therapy for Acute Non-Cardiogenic Stroke

Objective:To investigate the application value of thrombelastogram(TEG)in the detection of platelet inhibition rate for antiplatelet therapy for acute non-cardiogenic stroke.Methods:A total of 100 patients with ischemic non-cardiogenic stroke were selected for this study from September 2020 to October 2021.Patients were randomly divided into experimental group and control group,with 50 cases for each group.Before and after 1 week of antiplatelet drug treatment,the platelet inhibition rate in the experimental group was measured with arachidonic acid(AA)and adenosine diphosphate(ADP)by TEG;no platelet inhibition rates detection was conducted for the control group.The dose and type of drugs were adjusted for the experimental group according to the platelet functions and medication based on the clinical experience conducted for the control group.The neurological deficits of the discharged patients were scored with NIHSS score,mRS score,stroke recurrence,hemorrhage,and other events were followed up at the 3rd month of discharge.Results:In the experimental group,the inhibition rates of AA and ADP were significantly higher than those before treatment(both P<0.05).After treatment,the inhibition rates of AA and ADP in dual antiplatelet patients were higher than those of monoclonal antiplatelets(both P<0.05).The NIHSS score at discharge and the mRS score at the 3rd-month-follow-up in the experimental group were lower than those in the control group(both P<0.05).The incidences of stroke recurrence and hemorrhage events in the experimental group were lower than those in the control group(P<0.05).Conclusion:The application of a thrombelastogram in the detection of platelet inhibition rate to guide antiplatelet therapy in patients with acute non-cardiogenic stroke reduces the recurrences of cerebral infarction and the risk of hemorrhage and improves patients’clinical prognosis.

New flavanone-monoterpene hybrids as α-glucosidase inhibitors from the root bark of Morus alba

Objective The Morus alba root bark is a well-known Chinese herbal medicine called Sang-Bai-Pi and has often been used to relieve the hyperglycemic symptom of diabetes patients.The current work aims to further explore its bioactive constituents with α-glucosidase inhibitory activity for the potential treatment of diabetes.Methods A combination of different separating techniques including routine column chromatograph and HPLC especially on chiral columns were applied for the isolation of target molecules,while comprehensive spectroscopic experiments comprising MS,NMR,ECD,etc.were carried out to complete the structural assignment.The anti-hyperglycemic property of the isolates was evaluated by an in vitro α-glucosidase inhibitory bioassay.Results Two pairs of new flavanone-monoterpene hybrid enantiomers were isolated and identified,and an interesting phenomenon of mutual transformation between these cometabolites were detected,which resulted in their regio-isomerization and enantiomerization.The bioassay results revealed remarkable α-glucosidase inhibitory activity for these fascinating molecules.Conclusions The Morus alba root bark is a rich source of bioactive flavonoid derivatives and deserves further investigations to develop new potential chemotherapies for diabetes control and treatment.

Fluorescence microscopic morphology and inhibition ratestudies on apoptosis of osteosarcoma cells induced by ^(153)Sm

The apoptosis of osteosarcoma cells treated with irradiation by 153Sm-EDTMP was studied. The morphological changes in osteosarcoma cells were observed by fluorescence microscopy. It was found that osteosarcoma cells exposed with 153Sm-EDTMP displayed significant nuclear fragmentation and marked pyknosis. With the prolongation of observing period, the membrane bound apoptotic bodies formation was observed. It should be noted, that with the lengthening of irradiation time by 153Sm-EDTMP, the inhibition rate of proliferation of osteosarcoma cells increased progressively.

THE INHIBITION EFFECT OF ^(211)At-Te COLLOID AND Na^(211) At INJECTIONS ON MURINE EHRLICH ASCITES TUMOR CELLS

Na211 At and 211 At-Te colloid injections are prepared. It has been demonstrated that the 211 At-Te colloid is stable in vivo and vitro, and can be applied in the study of biology and medicine. In the report, the model of Murine Ehrlich Ascites Cells cultured in vivo and vitro is elected for a series of experiments. It has been proved that Na 211At and 211At-Te colloid injections possess an inhibition effect on tumor cells. The inhibition effect was expressed in surviving of the mice and inhibiting growth of tumor as well as the changes of enzyme activity. Meanwhile, it was also noticed that Na 211 At and 211 At-Te colloid injections of various dose inhibited the absorb of pyrimidine nucleosides in Murine Ehrlich Ascites Cells. And the effect isn’t reversible. It is closely related to the dose administratered and 50% inhibition rate needs about 1.48×105 Bq/ml culture.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective:To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum.Methods:The effects of oral treatment with hydro-ethanolic extract(125,250 and 500 mg/kg)of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level,serum enzyme markers for liver function,lipid profile,total protein,serum urea,serum creatinine,and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin.In vitro assays including glucose uptake in C2 C12 cells and 3 T3-L1 adipose tissues,α-glucosidase andα-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract.DPPH and nitric oxide radical antioxidant activity of the extract was also measured.Results:The increased levels of blood glucose,triglycerides,lowdensity lipoprotein,total cholesterol,serum aspartate,and alanine transaminases,creatinine,and urea in the diabetic animals were reduced significantly(P<0.01)after treatment with Chrysophyllum albidum extract.The decreased total protein and high-density lipoprotein concentrations were normalized after treatment.In addition,the extract significantly(P<0.01)increased the transport of glucose in 3 T3-L1 cells and C2 C12 myotubes and exhibited considerable potential to inhibitα-amylase andα-glucosidase.It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals.Conclusions:Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2 C12 myotubes and 3 T3-L1 adipocytes as well as inhibiting the activities ofα-amylase andα-glucosidase.

Correlation between Hemagglutination Inhibition Titer and Protection against Infectious Bronchitis Virus Challenge in SPF Layers

[ Objective] To study the correlation between HI titer and protection against IBV challenge in SPF layers. [ Method ] SPF layers were randomly divided into four groups, namely group A1, A2, B1 and B2. The group A1 was immunized with H120 live vaccine. The group A2 was first immunized with H120 live vaccine and later boosted with ND-IB-EDS trivalent inactivated vaccine. The group B1 was used as unimmunized chal- lenge control. The group B2 was kept as unimmunized unchallenged control. The blood samples were taken prior and post-vaccination at intervals and HI tests were conducted. At the laying peak, the group A1, A2 and B1 were challenged with IBV M4t virulent strain. The clinical features and egg production of layers were monitored and recorded. [Result] After 30 d post vaccination with H120 live vaccine, the HI titer reached 4.45 log2; after 30 days boosting with ND-IB-EDS trivalent inactivated vaccine, the HI titer reached to 7.35 log2. Before challenge, HI antibody titer in group A1, A2, B1 and B2 were respectively 4.24 log2, 7.40 Iog2, 2.10 log2 and 2.10 log2. After challenge, chickens in unimmunized challenge control group B1 showed respiratory symptoms, egg production dropped by 30.9%, and they produced more soft-shelled, no-shelled or abnormal eggs. In the group A1, some chickens had light respiratory symptoms and egg production dropped by 11.7%. In the group A2, the egg production of all chickens was as normal as the group B2. [ Conclusion] When the HI titer was over 6 log2, challenge by virulent virus had no impact on egg produc- tion; when the HI titer was 5 log2, 4 log2 and less 3 log2, egg production dropped by 6.0%, 11.3% and 29.6%, respectively. Thus, the HI anti- body level in chickens has close correlation with protection against IBV challenge.

新疆难解吸煤可溶有机质对瓦斯吸附解吸特征的影响研究

新疆焦煤公司煤层瓦斯难解吸,导致抽采难度增大。而煤中可溶有机质对瓦斯的吸附解吸有重要影响。为了研究其影响,使用四氢呋喃对煤中的可溶有机质进行抽提,采用低温氮吸附测试抽提前后煤的孔隙结构,利用煤岩高压瓦斯吸附装置进行抽提前后煤样的吸附解吸实验。研究结果表明:经过四氢呋喃抽提后,发现所有煤样的平均孔径、孔体积和比表面积均有不同程度的增大,认为煤中的可溶有机质被溶解,形成了新的微孔,同时原孔隙被扩大;4^(#)煤、5^(#)煤和6^(#)煤的吸附常数a分别减小了2.73%、16.09%、14.57%,4^(#)煤和5^(#)煤吸附常数b分别增大了12.18%、2.58%,6^(#)煤的吸附常数b减小了8.59%,煤的吸附能力降低,解吸速度增大,可溶有机质促进了煤对瓦斯的吸附。

AA抑制率和ADP抑制率对脑出血后再出血及预后的预测价值分析

目的 本研究的目的是评估血栓弹力图(thrombelasto graphy,TEG)测试中AA抑制率和ADP抑制率在预测脑出血(ICH)后再出血和不良功能预后方面的有效性。方法 选取苏州市立医院2019年4月至2022年6月之间114例出现症状6 h内接受CT检查的原发性脑出血患者作为研究对象,评估两组患者入院后TEG指标中花生四烯酸(AA)抑制率、二磷酸腺苷(ADP)抑制率等与脑出血后再出血及病残率、病死率等结局的关系,以及与格拉斯哥昏迷量表评分的相关性。结果 未再出血组AA抑制率和ADP抑制率均明显低于再出血组(P<0.05);再出血组中死亡患者AA抑制率和ADP抑制率均明显高于康复组及病残组(P<0.05);AA抑制率和ADP抑制率与GCS评分呈负相关(r=-0.702,P=0.008)。结论在脑出血后再出血及预后的评估中,AA抑制率和ADP抑制率具有较好的预测价值,值得临床推广。

不同药剂与施药时期对辣椒炭疽病防治效果的影响

【目的】探明贵州辣椒炭疽病的适宜防治药剂和防治时期,为辣椒炭疽病化学防控提供依据。【方法】选取已登记的15种辣椒炭疽病防治药剂单剂(25%咪鲜胺EC、80%波尔多液WP、50%肟菌酯WG、22.7%二氰蒽醌SC、70%代森锰锌WP、40%百菌清SC、30%琥胶肥酸铜WP、80%克菌丹WG、22.5%啶氧菌酯SC、85%三氯异氰尿酸SPX、40%苯醚甲环唑SC、500 g/L氟啶胺SC、50%咪鲜胺锰盐WP、250 g/L嘧菌酯SC和25%吡唑醚菌酯SC)和1个混剂(40%苯甲•吡唑酯SC)为药剂处理,选取贵州辣椒炭疽病的3个主要致病菌菌株(C.scovillei GL 17-25、C.gloeosporioides GL 17-42和C.fructicola GL 17-147)为防治对象,采用菌丝生长抑制法和离体果实接种法对药剂进行初筛,通过田间试验进一步验证适宜的药剂和防治时期。【结果】25%咪鲜胺EC、50%咪鲜胺锰盐WP、70%代森锰锌WP对3种辣椒炭疽病菌的菌丝生长抑制率均为100.00%;离体果实接种试验表明,除70%代森锰锌WP外,各药剂的平均预防效果均高于治疗效果,25%咪鲜胺EC对3个菌株的预防和治疗效果最好,平均值分别为72.48%和60.01%,其次为25%吡唑醚菌酯SC(43.53%和30.36%)。相比发病中期用药,发病初期用药的病情指数低、防效高,25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC的防效显著(P<0.05)高于25%咪鲜胺EC,前两者发病初期用药的防效分别为86.99%和88.59%,发病中期用药防效分别为50.87%和45.48%。【结论】25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC能有效防治辣椒炭疽病,防治时期以发病初期为佳。

BD-77雾化吸入给药对肺炎支原体感染小鼠的治疗作用

目的评价BD-77雾化吸入给药对肺炎支原体肺炎小鼠模型的治疗作用。方法Balb/c小鼠按照体质量随机分为正常对照组、模型对照组、阿奇霉素对照组(42 mg·kg^(-1)·d^(-1))、BD-77高剂量组(75 mg·mL^(-1),雾化15 min)、BD-77低剂量组(37.5 mg·mL^(-1),雾化15 min)。以肺炎支原体滴鼻感染建立小鼠支原体肺炎模型,雾化给药4 d后,通过小鼠体重及肺重计算肺指数和肺指数抑制率,酶联免疫吸附试验(ELISA)检测肺组织中白介素-6(IL-6)、白介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)含量及血清中C反应蛋白(CRP)水平,苏木精-伊红(HE)染色评估小鼠肺组织病理学变化,全面评价BD-77对小鼠支原体肺炎的治疗作用。结果BD-772个剂量组雾化吸入给药15 min均可显著降低小鼠肺指数,减轻肺部炎症病变,降低肺组织中IL-6、IL-1β、TNF-α含量及血清CRP水平。结论BD-77雾化吸入可治疗支原体感染小鼠肺炎,本研究为BD-77开发作为防治肺炎支原体肺炎的药物提供了实验室数据支持。

鳖甲煎丸对肝癌大鼠黏着斑激酶/雷帕霉素靶蛋白通路的影响

目的:探讨鳖甲煎丸对肝癌模型大鼠肝组织病理特征及FAK/mTORC1通路的影响。方法:HepG2(1×10^(7))细胞注射于大鼠右腋皮下,建立肝癌模型,分为模型组、5-氟尿嘧啶组、鳖甲煎丸低剂量组、鳖甲煎丸高剂量组,另设正常组。各药物组给予相应药物灌胃,持续给药4周,正常组、模型组给予等体积的0.9%氯化钠溶液。实验结束后,测定肝癌组织重量、肝癌组织体积、肝癌组织抑瘤率、肝癌FAK、mTORC1水平、肝癌VEGFR-2、VEGF、IL-4、IL-8、TNF-α蛋白水平。结果:与正常组比较,模型组肝癌组织重量、肝癌组织体积、肝癌组织抑瘤率、VEGFR-2、VEGF、IL-4、IL-8、TNF-α蛋白、肝癌FAK、mTORC1 mRNA和蛋白表达升高(均P<0.05)。与模型组比较,5-氟尿嘧啶组、鳖甲煎丸低剂量组、鳖甲煎丸高剂量组肝癌组织重量、肝癌组织体积、肝癌组织抑瘤率、VEGFR-2、VEGF、IL-4、IL-8、TNF-α蛋白、肝癌FAK、mTORC1 mRNA和蛋白表达降低(均P<0.05)。鳖甲煎丸高剂量组肝癌组织重量、肝癌组织体积、肝癌组织抑瘤率、VEGFR-2、VEGF、IL-4、IL-8、TNF-α蛋白、肝癌FAK、mTORC1 mRNA和蛋白表达低于鳖甲煎丸低剂量组(均P<0.05)。结论:鳖甲煎丸对大鼠肝癌具有明显抑制作用,能减轻大鼠肝癌所致的病理损伤,其机制可能与鳖甲煎丸抑制肝癌FAK、mTORC1表达,诱导肝癌细胞凋亡,降低炎症反应有关。

盐碱胁迫对水稻生长特性及产量的影响

为了有效利用并改良盐碱地及改善生态环境,以8份水稻种质资源为材料,设置轻度盐碱胁迫、中度盐碱胁迫、重度盐碱胁迫进行田间耐盐碱性分析,对植株存活率、株高、分蘖、叶绿素相对含量、每穗粒数、结实率以及千粒重等指标进行了比较,分析不同程度盐碱胁迫对水稻生长发育特性及产量的影响。结果表明,水稻品种间耐盐碱特性存在差异,水稻存活率表现为轻度盐碱胁迫>中度盐碱胁迫>重度盐碱胁迫,水稻品种从返青期至成熟期植株存活率呈下降趋势。盐碱胁迫导致水稻株高变矮、穗长变短,随着盐碱胁迫程度增加株高和穗长受到的抑制作用变强,同一品种株高和穗长数值表现为轻度盐碱胁迫>中度盐碱胁迫>重度盐碱胁迫,且3种盐碱胁迫处理间差异显著(P<0.05)。齐穗期SPAD值范围为42.5~55.6,各处理与对照间差异不显著。重度盐碱胁迫下水稻产量抑制率高达81.0%~93.7%,中度盐碱胁迫下产量抑制率为10.4%~81.3%,轻度盐碱胁迫下为5.6%~77.9%,产量及产量构成因素相对抑制率主要表现为重度盐碱胁迫>中度盐碱胁迫>轻度盐碱胁迫,盐碱化程度越高对水稻产量及产量构成因素造成的损失也越大。相关分析表明,产量相对抑制率与单位面积穗数相对抑制率极显著相关,与实粒数相对抑制率和结实率相对抑制率正相关。说明,盐碱胁迫抑制水稻生长发育,导致产量降低,但合理开发和利用中度、轻度盐碱化土地可以扩大水稻种植面积。

球毛壳菌小麦秸秆发酵产物抑制辣椒疫霉的稳定性及机制

【目的】由辣椒疫霉(Phytophthora capsici)侵染引起的疫病给辣椒等作物产业带来了巨大的经济损失。论文旨在明确球毛壳菌(Chaetomium globosum)代谢产物抑制辣椒疫霉的稳定性和抑菌机制,为研究与开发辣椒疫霉的微生物源抑菌剂提供参考。【方法】将球毛壳菌发酵粗提物分别在不同温度(40—121℃)、pH(1—13)、光照时间(0—12 d)和储存时间(0—60 d)条件下进行处理,采用菌丝生长抑制法测定经不同处理后粗提物对辣椒疫霉的抑制率,以探究粗提物抑制辣椒疫霉的热、酸碱、光和时间稳定性。利用光学显微镜观察粗提物对辣椒疫霉菌丝形态的影响,通过多种生理生化试验探究粗提物作用于辣椒疫霉12—72 h后,对辣椒疫霉细胞壁、细胞膜、活性氧代谢、蛋白质含量、还原糖含量和致病力的影响。【结果】在所设置的处理范围内,球毛壳菌发酵粗提物(1 mg·mL^(-1))经不同光照时间和储存时间处理后对辣椒疫霉的抑制率没有显著降低,抑制率维持在93%左右;粗提物在40—70℃的热处理范围内对辣椒疫霉的抑制率没有显著降低,70℃以上的热处理会显著降低粗提物对辣椒疫霉的抑制率,但抑制率不低于70%;粗提物在pH 1—5和9—13的酸碱处理范围内会显著降低对辣椒疫霉的抑制率,但抑制率也不低于70%。粗提物处理影响辣椒疫霉菌丝形态,使菌丝发生严重的扭曲皱缩现象,并影响活性氧代谢,使菌丝中的活性氧大量积累。辣椒疫霉经粗提物处理12—72 h后,其培养液中的碱性磷酸酶活性、β-葡萄糖苷酶活性、核酸和蛋白质含量均显著升高,且其菌丝中的丙二醛和过氧化氢含量显著增加。辣椒疫霉菌丝中的过氧化氢酶活性、可溶性蛋白和还原糖含量则在粗提物处理12—72 h内显著降低,而超氧化物歧化酶、过氧化物酶、多聚半乳糖醛酸酶和β-葡萄糖苷酶活性则仅在一定时间显著降低。【结论】在本试验所设置的处理范围内,球毛壳菌的小麦秸秆发酵粗提物抑制辣椒疫霉的效果不受光照及储存时间的影响,但超过70℃的热处理和pH 1—5和9—13的酸碱处理会显著降低粗提物对辣椒疫霉的抑制效果。此外,该粗提物通过改变菌丝形态,破坏细胞壁和细胞膜,引发细胞内物质泄漏,降低菌丝中蛋白质和还原糖含量,抑制抗氧化酶活性,干扰活性氧代谢使活性氧大量积累从而抑制辣椒疫霉。

抗肿瘤药效研究中疗效与安全性综合评价指标的选择

目的传统抗肿瘤药效评价指标中体质量、肿瘤体积和抑瘤率可以分别体现制剂的安全性和疗效,但是单一指标并不能兼顾这两点。为此,新的抗肿瘤药效评价指标被提出,其中抑瘤指数可以全面地呈现药物的治疗效果。方法以表柔比星相关制剂的药效学实验数据为例,对“新”和“旧”抗肿瘤评价指标的统计结果进行分析。结果聚乙二醇修饰脂质体组内小鼠的抑瘤率(0.80±0.05)与唾液酸修饰脂质体组内小鼠的抑瘤率(0.89±0.01)无显著性差异(P≥0.05),但是聚乙二醇修饰脂质体组内小鼠的抑瘤指数(40±9)显著低于唾液酸修饰脂质体组内小鼠的抑瘤指数(82±7,P<0.001)。结论“新”抗肿瘤评价指标更适合用于抗肿瘤研究的数据分析。

不同药剂对高粱炭疽病菌的室内毒力与复配增效研究

【目的】探明对高粱炭疽病菌具有良好抑制作用的杀菌剂及增效作用明显的复配药剂组合,为高粱炭疽病的田间防治提供科学依据。【方法】采用菌丝生长速率法测定戊唑醇、咪鲜胺、吡唑醚菌酯、肟菌酯、异菌脲和噻呋酰胺6种药剂在不同浓度下对高粱炭疽病菌的抑制率及EC_(50);根据测定结果,选取活性较高的2种药剂按不同比例复配,测定复配剂对高粱炭疽病菌的抑制率、EC_(50)、共毒系数(CTC)及联合毒力,以评价其增效作用,确定最佳复配比例。【结果】6种供试药剂对高粱炭疽病菌均有不同程度的抑制作用,其中,97%咪鲜胺TC的毒力最强,EC_(50)为0.0021 mg/L;98%吡唑醚菌酯TC次之,EC_(50)为0.6103 mg/L。97%咪酰胺TC与98%吡唑醚菌酯TC复配比例为9︰1时,抑制效果最佳,EC_(50)为0.0015 mg/L,CTC为155.49;复配比例为1︰3时,增效作用最佳,EC_(50)为0.0036 mg/L,CTC为230.95。【结论】97%咪酰胺TC与98%吡唑醚菌酯TC复配比例为1︰3的增效作用最佳,具有良好的抑菌活性,可推广应用于田间防控高粱炭疽病。

不同玉米自交系对环磺酮的敏感性差异研究

环磺酮是2021年在中国登记上市的玉米田对羟基苯基丙酮酸双氧化酶(HPPD)抑制剂类除草剂。为明确环磺酮对不同玉米自交系的安全性,以玉米自交系HB05(‘Mo17’)、HB09(‘PH6WC’)、HB39(‘J525’)和HB82(‘’KH8’)为研究对象,进行了环磺酮胁迫对不同玉米自交系幼苗生长及体内生理生化指标的影响研究。结果表明:环磺酮按有效成分120 g/hm^(2)处理,敏感型玉米HB82和HB39表现出叶片失绿白化,直至干枯死亡,严重影响玉米的生长发育;而耐药型玉米HB05和HB09叶片没有出现受害症状,对生长发育无明显影响。环磺酮按有效成分240 g/hm^(2)处理14 d后,对敏感型玉米HB82和HB39株高抑制率分别为64.63%和63.79%,鲜重抑制率分别为70.06%和66.02%。环磺酮按有效成分720 g/hm^(2)处理14 d后,对耐药型玉米HB05和HB09株高抑制率分别为48.61%和38.05%,鲜重抑制率分别为21.93%和43.63%。环磺酮对耐药型玉米HB05和HB09的IC50值分别为223.50和37.42 mg/L,明显高于敏感型玉米HB82和HB39(对的IC50值分别为13.48和16.13 mg/L)。对叶绿素含量测定结果表明:叶绿素a、叶绿素b和叶绿素总含量的变化趋势一致,即随着处理时间的延长,不同玉米自交系体内叶绿素含量呈不同程度的下降趋势,且敏感型玉米下降趋势明显大于耐药型玉米。环磺酮按有效成分120 g/hm^(2)处理7 d后,与0 d相比,敏感型玉米HB82、HB39体内叶绿素总含量较0 d分别下降87.76%和70.55%,而耐药型玉米HB05和HB09分别下降49.86%和33.65%;敏感型玉米HB82和HB39体内类胡萝卜素含量分别下降83.72%和74.02%,耐药型玉米HB05和HB09分别下降40.83%和33.33%。对超氧化物歧化酶(SOD)和过氧化物酶(POD)酶活性的测定结果表明:环磺酮胁迫诱导了不同玉米自交系体内SOD和POD酶活性的增加,呈先上升后下降的趋势,其变化幅度为敏感型玉米高于耐药型玉米。综上所述,不同玉米自交系对环磺酮的敏感性存在显著差异,明确不同玉米自交系对环磺酮的耐药性,在生产中可避免环磺酮对玉米产生药害,减少不必要的损失。

马来酸酐与烯丙基磺酸钠共聚物的聚合过程及阻垢性能

为了分析马来酸酐(MA)与烯丙基磺酸钠(SAS)聚合过程的影响因素,在配方和工艺基本不变的情况下,设计了两种变量:中和度和引发剂加量。通过改变其中一个变量,合成了一系列MA/SAS共聚物,采用核磁共振波谱仪和凝胶渗透色谱仪对产物进行了表征。结果表明,MA与SAS共聚活性良好,中和度不超过100%时(相对于MA的物质的量分数),少量引发剂加量(2.4 g过硫酸钠)下就有较高的单体转化率,但仍有6%~8%的单体未聚合。剩余单体的种类和数量与中和度以及引发剂加量息息相关。MA在水溶液中部分水解成了马来酸,尽管马来酸数量较少,但其聚合活性相对较差,导致共聚物的分子量呈双峰分布。添加碱可以中和马来酸,当中和度不超过100%时,马来酸主要变为具有较好聚合活性的马来酸单钠盐,间接促进了MA类单体的聚合;当中和度为200%时,马来酸主要变为马来酸二钠盐,其聚合活性相对较差,严重阻碍了聚合;未中和以及中和度为100%时,需7.0~7.2 g引发剂才能将单体全部转化,而在适当的中和度(约20%)下,用少量引发剂(4.0~4.2 g)就可以获得聚合较完全的共聚物,节约了大约40%的引发剂用量。用较佳条件下合成的MA/SAS共聚物对碳酸钙、磷酸钙和硫酸钙的静态阻垢性能进行了研究,共聚物表现出良好的阻磷酸钙垢和阻硫酸钙垢、较好的阻碳酸钙垢性能,对应的最大阻垢率分别为94.38%、100.00%、59.03%。