我国车用代用燃料研发与应用现状

根据我国能源生产和消费的现状，论述了开发车用代用燃料的必要性和紧迫性；介绍了代用燃料的概念及对车用代用燃料的要求；分析了天然气、生物柴油、醇类及二甲醚等适合我国国情的代用燃料的特性、应用现状、发展前景。同时，提出了在推广应用中应注意的问题及其建议。     

A potential calcium antagonist and its antihypertensive effects

Imperatorin (Imp) as a hypotensive active ingredient, its hypotensive effect was evaluated in the SHRs, its calcium antagonism and affinity to L-type calcium channel was also confirmed. The results showed that the blood pressure was decreased in the SHRs treated with Imp, the aortic ring was relaxed with Imp, L-type calcium channel currents and intracellular calcium free ion rise was nearly disappeared when adding Imp. In addition, Imp displayed a chromatographic peak similar to nitrendipine and verapamil by the cell membrane chromatography, same results from protein–drug docking approaches. Hence, Imp target the L-type calcium channel, and may be used as a novel antihypertensive drug.     

大气环境中二甲基硫的研究进展

二甲基硫(DMS)作为大气环境中较为活跃的有机硫气体,是全球硫循环的主要驱动成分,并在气候变化中产生重要的负温室效应。本研究整理、归纳了大气环境中DMS的国内外研究进展,并以Web of Science为数据库,分别以“dimethyl sulfide”和“air”,“dimethyl sulfide”和“atmosphere”,“dimethyl sulfide”和“atmospheric”为关键词,搜索1900—2020年国内外发表的文献,并运用文献计量学的方法对1 997篇文献进行研究动态分析,结果表明:1)已有研究主要集中在海洋浮游植物和细菌产DMS的过程、全球DMS海、气通量的模型估算、大气中DMS的消除途径及其氧化产物的辐射效应等问题上;2)全球变暖的趋势下,对DMS海洋源响应过程的关注度逐渐提高;3)非海洋地区DMS的来源及排放量认识尚不全面,且随着社会经济的发展,以往的研究有可能低估DMS非海洋源的贡献及其环境影响。探究全球气候变暖对DMS释放过程的影响及量化分析DMS非海洋源的贡献,是未来深入探究的方向。     

山东桔梗多倍体诱导与鉴定

在离体培养条件下,比较了单用不同浓度秋水仙素和0．2％秋水仙素与不同浓度二甲基亚砜（DMSO）混用对山东桔梗愈伤组织诱导多倍体的效果。结果表明：用0．2％秋水仙素和2％DMSO浸泡山东桔梗愈伤组织16h,多倍体诱导率最高,达43．3％。桔梗多倍体植株叶颜色深、有皱褶,叶片大且厚,茎秆粗壮,节间距长。经显微鉴定,多倍体叶气孔增大,但单位面积气孔数目减少。     

丙硫咪唑在鸡体内的药代动力学及组织残留的研究

给鸡单剂量口服丙硫咪唑(15mg/kg),用HPLC法测定不同时间的鸡体内药物及其代谢物的浓度.结果,在血浆和组织中均未发现丙硫咪唑,而其两个代谢物丙硫咪唑亚砜(亚砜)和丙硫咪唑砜(砜)在血浆中的药代动力学行为符合方程:C(亚砜)=22.3581(e~(-0.142(t-0.6053))-e~(-0.4505(t-0.8053)));C(砜)=4951.7774(e~(-0.2769(t-0.9111))-e~(0.278(t-0.9111)))。亚砜和砜的主要药动学参数分别为:消除相半衰期(t1/2ke)为4.87和2.57h,表观分布容积(Vd)为0.98和0.76L/kg,峰时间(Tm)为4.34和4.52h,峰浓度(Cm)为8.98和7.22μg/mL。亚砜在心、肝、胰、肺、肾等组织中的残留量:给药后3d分别为1.14、5.35、2.42、1.78、2.45μg/g;5d分别为0.281.79、2.34、1.13、1.16μg/g;7d分别为0.12、0.68、1.69、0.48、0.69μg/g.砜在上述组织中的残留量:给药后3d分别为3.15、10.44、8.16、0.99、2.83μg/g;5d分别为1.53、1.04、4.11、0.86、0 89μg/g;7d分别为:0.77、0.67、2.09、0.53、0.12μg/g。     

新型水产诱食剂氯化羧甲基二甲基锍的合成

运用无溶剂合成方法,利用较低成本的氯乙酸为原料与二甲硫醚反应,合成新型水产动物诱食剂——氯化羧甲基二甲基锍。该化合物通过1HNMR、13CNMR、MS和元素分析证实了其结构。通过正交实验法,获得较佳反应条件:反应温度为75℃,反应时间12h,n氯乙酸:n二甲基硫醚=1:1.18,收率达到72.2%。     

Topical Dexamethasone and Dimethyl Sulfoxide Solutions Do Not Result in Detectable Blood Levels of Dexamethasone

Dexamethasone is a potent corticosteroid anti-inflammatory agent, and in most jurisdictions it is not legal to administer to any horse on the day of a race. This study was conducted to determine whether topical combination of dexamethasone and dimethyl sulfoxide (DMSO) solutions would result in detectable dexamethasone in the blood or urine in horses. Five different concentrations of dexamethasone/DMSO were used to replicate the combinations used on race horses. Serum cortisol concentrations were determined to detect an alteration in the hypothalamus-pituitary-adrenal axis. Dexamethasone/DMSO mixtures were applied topically to the distal limbs in five Standardbred mares. Blood and urine samples were collected at 0, 8, 24, and 32 hours. Samples were originally screened by a commercially available enzyme-linked immunosorbent assay (ELISA) test for dexamethasone. Any samples that were deemed suspect were then analyzed by liquid chromatography/mass spectrometry (LC/MS). Blood cortisol was assayed using a solid-phase chemiluminescence enzyme immunoassay. There was no detectable dexamethasone in either the urine or serum of any horse at any time point. The serum cortisol concentrations were within our laboratory's normal range at all time points. It appears doubtful that detectable blood and urine concentrations of dexamethasone are attributable to absorption from a topical application through intact skin.     

完全不渗透膜对熏蒸剂防治土传病虫害的影响

完全不渗透膜(TIF膜)对熏蒸剂具有很好的阻隔性,但对熏蒸剂防治土传病虫害的影响还不明确。测定了TIF膜对二甲基二硫、棉隆及1,3-二氯丙烯防治黄瓜土传病害、黄瓜长势、产量及收入的影响,结果表明,在熏蒸剂低用量时,覆盖TIF膜相对PE膜能显著提高熏蒸剂对土壤根结线虫(Meloidogyne spp.)、疫霉菌(Phytophthora spp.)和镰刀菌(Fusarium spp.)的防治效果;并且熏蒸剂低用量时覆盖TIF膜后的产量与熏蒸剂高剂量时覆盖PE膜的产量无显著差异。应用TIF膜可以显著降低熏蒸剂用量,且不影响防治效果,同时也降低了熏蒸剂挥发对施药人员造成的危害,所以TIF膜是有前景的土壤消毒专用膜。     

二甲基硫醚氧化菌的分离鉴定及其对猪粪堆肥的影响

从污水处理厂活性污泥中分离得到一株二甲基硫醚(DMS)氧化菌AM2,经16S rDNA检测鉴定其为那不勒斯硫杆菌(Thiobcillus neapolitanus)。AM2的最适生长温度为30℃最适pH为7.0。以猪粪和秸秆粉为原料进行肥料堆肥试验,通过检验菌株AM2对堆肥过程中DMS排放量、堆肥温度、可培养微生物和酶活性的影响,来探究菌株AM2对堆肥的影响。结果表明:接入菌株AM2的实验组DMS释放量显著(P0.05)少于对照组,在30 d的实验中有20 d减少60%以上;显著提高了(P0.05)可培养微生物数量,同时将物料温度高于50℃的天数延长至13 d;实验各组的脲酶、脱氢酶、过氧化氢酶、蛋白酶和纤维素酶酶活都显著高于对照组。综合判断,菌株AM2能够有效降低堆肥过程中DMS的排放量并促进肥料腐熟。     

硫酸二甲酯对白花泡桐丛枝病幼苗形态变化及DNA碱基序列的影响

利用巢式PCR和SSR技术研究了0,15,25,50,75,100,125,150 mg·L-1的硫酸二甲酯(DMS)对白花泡桐幼苗形态、植原体和DNA碱基序列的影响.结果表明,15 mg· L-1DMS处理3h可使丛枝病幼苗转变为形态上健康幼苗,但其幼苗内仍有丛枝病植原体的存在;25～125 mg· L-1 DMS处...