蔬菜中有机磷农药残留的高效液相色谱分析

应用高效液相色谱法测定蔬菜中有机磷农药残留量。采用高效液相色谱法,C18色谱柱、流动相为甲醇：水(V：V)=70：30,用紫外检测器检测。测定了蔬菜中甲1605和久效磷两种常用有机磷农药的残留量。该法相关性好,线性范围广,精密度高,准确度好。     

广州地区农产品中有机磷农药残留调查

采用国家标准方法气相色谱(GC)法进行分析,通过对蔬菜、水果、粮食中16种有机磷农药残留量的检测,了解有机磷农药在广州地区农产品中的残留及其分布情况.50份农产品样品中有机磷农药各组分总的检出率为96.0%,其中蔬菜、水果、粮食检出率分别为96.8%、100%、80.0%.50份农产品样品中有机磷农药各组分总的超标率为36.0%,其中蔬菜、水果、粮食超标率分别为41.9%、21.4%、40.0%,16种有机磷农药中以马拉硫磷的超标率最高,为32.0%.不同组分有机磷农药在农产品中的残留量,以杀螟磷的平均含量最高,为1308.7μg·kg^-1,其次是辛硫磷和甲胺磷,分别为970.1μg·kg^-1和737.6μg·kg^-1;因此应提倡合理使用农药,加强农药使用的引导和监管.     

八种石斛中苯丙醇类和香豆素类化合物含量测定与分析

新建HPLC双波长同时测定松柏苷、紫丁香苷、东莨菪内酯、滨蒿内酯及香豆素含量的分析方法。采用Shiseido CAPCELL PAK MGⅡC₁₈柱(250 mm×4.6 mm,5μm)分析柱;使用乙腈-水为流动相,梯度洗脱;流速为0.8 mL/min;紫外检测器260 nm,315 nm双波长检测。结果显示,五种成分在测定范围内有良好的线(r^2>0.999);在三个加标浓度下方法回收率为98.7%～102.5%之间,相对标准偏差(RSD)小于2.5%。该方法用于8种石斛品种含量的测定。     

茶叶上拟除虫菊酯类农药降解菌的分离及其特性

生物修复对降解污染基质中的农药是一种对环境有益的方法。目标是要寻找能够降解在茶叶生产中使用的拟除虫菊酯类农药的降解菌。最终在福州某茶园经农药处理过的茶叶中分离降解菌。首先在富集培养基中筛选,接着在以农药为唯一碳源的基础培养基中连续筛选。结果发现,其中一株标号为c1f6的菌株生长的特别良好,经AMS-VITEK120全自动微生物分析系统鉴定,为假单胞菌属的一个未知种。采用HP6890气相色谱仪测定菌株对拟除虫菊酯类农药联苯菊酯、甲氰菊酯和氯氰菊酯的降解率。在pH7.0的基础培养基发酵液中,以各加100mg·L-1这3种农药为唯一碳源,30℃振荡培养,接种c1f6后3d,这3种农药的降解率分别为55.64%、44.56%和52.19%。采用光密度测定的菌株生长值和农药降解率的关系曲线表明,在基础培养基中,农药降解和菌株生长成正相关,说明菌株能以拟除虫菊酯类农药为唯一碳源和能源进行生长。采用同样的方法测定表明,菌株c1f6对有机磷农药也有一定的降解力,3d对甲胺磷和毒死蜱的降解率分别为27.67%和12.35%。因此,假单胞菌c1f6是一株较广谱的农药降解菌,有望用于生物修复过程,以减少茶叶栽培过程中的产品和环境污染。     

用鱼脑胆碱酯酶活力监测有机磷农药对水体的污染

本文报道了6种有机磷农药(马拉硫磷、敌敌畏、对硫磷、敌百虫、乐果和杀螟松),6种非有机磷毒物(西维因、氯化高汞、滴滴涕、六六六、三硝基甲苯和苯酚)分别对我国淡水养殖鲤科鱼类的急性致毒试验,以及不同水体中不同种类和年龄的鱼的脑胆碱酯酶活力的测定,证实有机磷农药可以特异地抑制鱼脑胆碱酯酶活力,其抑制程度与农药浓度相关。在有机磷农药对鱼类慢性致毒试验中发现:水中有机磷农药浓度和水温对鱼脑胆碱酯酶活力的恢复和鱼体残毒释放的速度有影响。六六六和对硫磷联合致毒对鱼脑胆碱酯酶活力的影响也进行了初步探讨。       

急性有机磷农药中毒患者急救研究进展

<正>急性有机磷农药中毒是我国临床中常见的危急重症之一,尤以农村地区较为常见。急性有机磷农药经口与呼吸道吸入后经血液迅速分布至全身重要器官,具有较高病死率,据报道在5%~50%之间[1]。目前,有机磷农药是我国应用范围最广、应用量最大的杀虫剂,在有机磷农药生产、运输和应用过程中,稍有不慎即可发生急性中毒[2]。因此,提高对     

气相色谱法测定银杏内酯衍生物中有机溶剂残留量

建立了气相色谱法测定银杏内酯衍生物中甲醇、丙酮、乙腈、乙酸乙酯等有机溶剂残留量的方法.以苯为内标,样品经溶解直接进样测定,色谱柱为CP-SIL 24CB 毛细管柱(30 m×0.25 mm×0.25 μm).有机溶剂添加回收率在96.9%～99.6%之间,有机溶剂的最小检出限在0.29～0.48 μg /mL之间.该方法快速、准确、操作简便,能满足银杏内酯酯衍生物中甲醇等有机溶剂残留的定量检测.     

用鱼脑胆碱酯酶活力监测有机磷农药对水体的污染

本文报道了6种有机磷农药(马拉硫磷、敌敌畏、对硫磷、敌百虫、乐果和杀螟松),6种非有机磷毒物(西维因、氯化高汞、滴滴涕、六六六、三硝基甲苯和苯酚)分别对我国淡水养殖鲤科鱼类的急性致毒试验,以及不同水体中不同种类和年龄的鱼的脑胆碱酯酶活力的测定,证实有机磷农药可以特异地抑制鱼脑胆碱酯酶活力,其抑制程度与农药浓度相关。在有机磷农药对鱼类慢性致毒试验中发现：水中有机磷农药浓度和水温对鱼脑胆碱酯酶活力的恢复和鱼体残毒释放的速度有影响。六六六和对硫磷联合致毒对鱼脑胆碱酯酶活力的影响也进行了初步探讨。     

AccQ·Tag法测定绿豆蛋白酶解液中氨基酸含量

采用柱前衍生高效液相色谱法(AccQ·Tag法)同时测定17种氨基酸,氨基酸浓度在10～100μmol·L-1(胱氨酸浓度在5～50μmol·L-1)时,其峰面积和氨基酸浓度的线性相关系数均在0.99以上,17种氨基酸的加标回收率在92.1%～103.7%之间,用此法测定了绿豆蛋白酶解液氨基酸的含量,取得了满意的结果。     

浙江省商品竹林土壤有机农药污染评价

选取浙江省主要产竹区4县(市)商品竹林27个样地,对土壤主要有机农药残留进行检测分析.结果表明:残留的有机农药种类为有机氯(organochlorine pesticides,OCP)、有机磷(organophosphorus pesticides,OPP)和拟除虫菊农药(pyrethroid,PY),未检测出氨基甲酸酯类农药残留.有机氯农药残留种类为HCH、DDT、百菌清、五氯硝基苯、三氯杀螨醇,其中,HCH、DDT检出率分别为100%和70.37%.有机磷农药残留种类为甲基对硫磷、对硫磷、甲胺磷和乐果,其中,甲基对硫磷检出率96.30%.拟除虫菊酯类农药残留种类为氯氰菊酯、顺-氰戊菊酯,检出率分别为18.52%和62.90%;顺-氰戊菊酯残留量达1 227.14μg·kg-1,其他种类农药残留量低于150 μg·kg-1;这说明,试验取样区商品竹林土壤普遍存在有机农药污染:有机氯、有机磷残留量较低,拟除虫菊酯类农药残留较高.竹林经营类型、经营水平、土地利用方式对竹林土壤有机农药残留有一定的影响,集约经营竹林显著高于粗放经营竹林,笋用竹林较毛竹笋材两用林高,山地竹林较原农业耕作地改种为竹林的低.     

User perceptions on coastal resource state and management options in Curaçao

Public environmental awareness and support for management measures are key determinants of the scope for successful implementation of natural resource management. To assess user perceptions and opinions on resource state and potential management options for the coastal zone of Cura?ao, we queried 250 coastal resource users from around the island (sport divers, part-time artisanal fishermen and recreational boaters) using questionnaires. There is wide awareness of a long-term decline in coastal resource condition as measured by various indicators. Even among fishermen there was wide awareness of anthropogenic contributors to the decline, broad agreement of management measures required and a general willingness to contribute to management by means of annual license fees. Some of the more salient findings include the endorsement by fishermen of the current ban on spearfishing (81%), the regulation of the beach seine fishery for scad (77%), the introduction of fish reserves (72%), special protection for sea turtles (90%), conch (82%), and lobsters (72%), and notable support for gradual elimination of trap fisheries (45%). Also, both divers (65%) and boaters (92%) expressed the importance to them of an attractive coastline, with both groups expressing preference for natural (un-built) coastline (>74%) above other categories. Management based on the concept "user pays", as already implemented in the Netherlands Antilles on Saba and Bonaire, is well supported by the resource user public. A review of other main constraints such as finances and institutional capacity, shows that conditions are quite favorable for implementation of new legislation. Modem coral reef management is urgently needed in Cura?ao to safeguard a key natural resource and concerted action is called for on the part of government agencies, legislators and elected officials.     

In house reverse membrane hybridisation assay versus GenoType MTBDRplus and their performance to detect mutations in the genes rpoB,katG and inhA

Drug-resistant tuberculosis (TB) threatens global TB control and is a major public health concern in several countries. We therefore developed a multiplex assay (LINE-TB/MDR) that is able to identify the most frequent mutations related to rifampicin (RMP) and isoniazid (INH) resistance. The assay is based on multiplex polymerase chain reaction, membrane hybridisation and colorimetric detection targeting of rpoB and katG genes, as well as the inhA promoter, which are all known to carry specific mutations associated with multidrug-resistant TB (MDR-TB). The assay was validated on a reference panel of 108 M. tuberculosis isolates that were characterised by the proportion method and by DNA sequencing of the targets. When comparing the performance of LINE-TB/MDR with DNA sequencing, the sensitivity, specificity and agreement were 100%, 100% and 100%, respectively, for RMP and 77.6%, 90.6% and 88.9%, respectively, for INH. Using drug sensibility testing as a reference standard, the performance of LINE-TB/MDR regarding sensitivity, specificity and agreement was 100%, 100% and 100% (95%), respectively, for RMP and 77%, 100% and 88.7% (82.2-95.1), respectively, for INH. LINE-TB/MDR was compared with GenoType MTBDRplus for 65 isolates, resulting in an agreement of 93.6% (86.7-97.5) for RIF and 87.4% (84.3-96.2) for INH. LINE-TB/MDR warrants further clinical validation and may be an affordable alternative for MDR-TB diagnosis.     

Vertebrate invaders and their ecological impacts in Chile

The South American country of Chile has been subjected to relatively few invasions in historic times. In comparison to the ca 610 vertebrate species found in continental Chile, only 24 species (3.9%) have invaded the country. Except for two bird and two or three mammal species that expanded their range and crossed the Andean Ranges from Argentina, the remaining 20 species were all introduced, or aided, by humans. Of the 24 invader species that currently occur in Chile, 11 (46%) were first introduced in central Chile, two (8%) in the northern part of the country, nine (38%) in the southern part, and two (8%) in Juan Fernández Archipelago. For ten (42%) of those species there is no information about their effects on the native flora, vegetation, or fauna. For eight species (33%), the information regarding the effects of the invaders is anecdotal. For six species (25%), there is adequate quantitative documentation available on their effects. Of a total of seven convincingly repo rted cases, two involve positive effects (increase in the prey base for native predators) and five have negative effects, of which three are on native vegetation and the remaining two on native fauna.     

The role of phadiatop in the screening of respiratory allergy

Phadiatop is a new in vitro screening test for respiratory allergy. This test, based on the RAST procedure, detects in serum, the presence of specific IgE to a mixture of common inhalent allergens. Among 70 patients (26 children and 44 adults) consulting for respiratory syndrome, Phadiatop was positive in 31 cases. There were a good correlation between this new test and skin tests (59% for adults and 92% for children), total IgE (70% for adults and 65% for children) and RAST (93% for adults and 96% for children). Phadiatop, with a specificity of 100%, a sensitivity of 82% (76% for adults and 92% for children) and an efficiency of 90% (86% for adults and 96% for children), is a more accurate test than total IgE and could be an excellent in vitro screening test for respiratory allergy.     

Mapping quantitative trait loci associated with selenate tolerance in Arabidopsis thaliana

Selenium is essential for many organisms, but is toxic at higher levels. To investigate the genetic basis of selenate tolerance in Arabidopsis thaliana, quantitative trait loci (QTL) associated with selenate tolerance in accessions Landsberg erecta and Columbia were mapped using recombinant inbred lines (RILs). The selenate tolerance index (TI(D10) = root growth + 30 microm selenate/root growth control x 100%) was fourfold higher for parental line Col-4 (59%) than for parent Ler-0 (15%). Among the 96 F8 RILs, TI(D10) ranged from 11 to 75% (mean 37%). Using composite interval mapping, three QTL were found on chromosomes 1, 3 and 5, which together explained 24% of variation in TI(D10) and 32% of the phenotypic variation for the difference in root length +/- Se (RL(D10)). Highly significant epistatic interactions between the QTL and markers on chromosome 2 explained additional variation for both traits. Potential candidate genes for Se tolerance in each of the QTL regions are discussed. These results offer insight into the genetic basis of selenate tolerance, and may be useful for identification of selenate-tolerance genes.     

Achieving 80% ten-fold cross-validated accuracy for secondary structure prediction by large-scale training

An integrated system of neural networks, called SPINE, is established and optimized for predicting structural properties of proteins. SPINE is applied to three-state secondary-structure and residue-solvent-accessibility (RSA) prediction in this paper. The integrated neural networks are carefully trained with a large dataset of 2640 chains, sequence profiles generated from multiple sequence alignment, representative amino acid properties, a slow learning rate, overfitting protection, and an optimized sliding-widow size. More than 200,000 weights in SPINE are optimized by maximizing the accuracy measured by Q(3) (the percentage of correctly classified residues). SPINE yields a 10-fold cross-validated accuracy of 79.5% (80.0% for chains of length between 50 and 300) in secondary-structure prediction after one-month (CPU time) training on 22 processors. An accuracy of 87.5% is achieved for exposed residues (RSA >95%). The latter approaches the theoretical upper limit of 88-90% accuracy in assigning secondary structures. An accuracy of 73% for three-state solvent-accessibility prediction (25%/75% cutoff) and 79.3% for two-state prediction (25% cutoff) is also obtained.     

Diaminonaphtalene, a new highly specific reagent for HPLC-UV measurement of total and free malondialdehyde in human plasma or serum.

We describe a new method to measure free and total malondialdehyde (MDA) in human plasma or serum, which is based on the derivatization of MDA with diaminonaphtalene (DAN) in an acidic medium at 37 degrees C. Derivatization is complete after 180 min at room temperature. By HPLC separation on a C18 column and diode array detection, the diazepinium thus formed exhibits a highly specific UV spectrum with a sharp maximum at 311 nm, which clearly distinguishes MDA from other short-chain aldehydes. Direct injection of deproteinized plasma avoids the use of an internal standard. The between-run imprecision is 9.1% (141 +/- 13 nM) for plasma and 6.6% (658 +/- 44 nM) for a commercial control. Typical within-day imprecision is 8% (93 +/- 7.5 nM) for total MDA, 3.2% (16 +/- 0.5 nM) for free MDA in plasma, and 1.6% (630 +/- 10 nM) for a commercial control. The recovery of MDA added to 10 different plasmas is 93-108% (mean = 100%). Plasma levels in healthy women (n = 79, 45-51 years) are 162 +/- 51 and 24 +/- 15 nM for total and free MDA, respectively. In younger men (n = 19, 21-37 years) total and free MDA are, respectively, 138 +/- 28 and 19 +/- 9 nM.     

Carbon and Water Footprints and Energy Use of Greenhouse Tomato Production in Northern Italy

This study reports on the carbon, water, and energy footprints of tomatoes grown in a greenhouse in Northern Italy and two possible future variations of heating and carbon dioxide (CO₂) fertilization on the current setup. The heat supply in place, consisting of natural gas (NG) and canola oil combustion, is compared to cogeneration and incineration of municipal solid waste for heating and CO₂ from industrial exhaust for fertilization. As a benchmark, the current system is also compared to a conventional system, in which heat is delivered solely based on NG. Each kilogram (kg) of fresh tomatoes (“Cuore di Bue” variety) produced in the current greenhouse emits 2.28 kg CO₂ equivalents (eq) and uses 95.5 megajoules (MJ) eq energy and 122 liters (L) of water. Relative to the system in place, the carbon footprint (CF) is 57.5% and 18% higher with conventional NG heating and cogeneration and is 40% lower with waste valorization. Further, 33%, 55%, and 63% less energy and 9%, 96%, and 14% less water are used in the conventional, cogeneration, and waste valorization scenarios, respectively. This confirms that there are multiple strategies to reduce the impact of the tomato production under consideration.     

Ovulation pattern in successive cycles in the baboon

The purpose of this study was to determine if the selection of the side on which ovulation occurs in successive cycles is a random event. Forty-seven baboons were observed for four consecutive cycles and 37 for two to three consecutive cycles. Side of ovulation was determined by laparoscopic examination. Of the 286 cycles studied, 146 cycles (51 %) showed ovulations on the left side and 140 cycles (49 %) on the right. Analysis of the data using two consecutive ovulations in 286 cycles revealed that the selection of the side of ovulation is a random event. However, when four consecutive ovulations observed in 47 baboons were analyzed, it was found that the observed pattern of ovulation was different from that expected from random chance (p>0.05). There are 16 possible combinations in a sequence of four ovulations. Eight of 47 baboons (17 %) ovulated on the same side for four consecutive cycles, 15 baboons (32 %) ovulated three times on the same side for four ovulations, and 24 baboons (51 %) showed two ovulations on each side. Alternation of ovulation in a sequence of four consecutive ovulations was observed 48 times (25.5 %) and alternation of ovulation in two consecutive cycles was observed 106 times (51 %).     

中国人肱骨滑车上孔的调查

本文应用Martin方法,对在西安地区坟墓中收集的213副(男122,女91)中国成人肱骨滑车上孔的出现率、形状、数目和径线进行了调查。结果表明:滑车上孔出现率为11％,女性大于男性,其出现率女性与男性之比为2.29:1。通过比较得知,中国人滑车上孔出现率与日本人、朝鲜人相近,较白种人为高,而比黑种人低。滑车上孔之形状大部分(78.72％)为横椭圆形;在一个肱骨上出现一个滑车上孔者占97.87％。本文还对该孔出现的原因进行了探讨。