快速检测法在蔬菜农药残留含量调查分析中的应用

为了调查河源市夏秋季市售蔬菜农药残留状况,验证快速检测法测定农药残留样品的适用性,应用食品安全快速检测技术,采用多通道农药残留快速测试仪,对蔬菜进行农药残留取样检测,并对快检超标样品进行色谱检测复检。总取样量354个,包括生菜、苦瓜、茄子、上海青、蒜苗、西芹菜、菜心等蔬菜。结果显示:农药残留快速检测法总检出率93.50%(331/354),快速检测总超标率12.15%(43/354),实际总超标率5.93%(21/354);仅蒜苗和西芹菜出现假阳性,假阳性率分别为90.48%(19/21)和75.00%(3/4),其余蔬菜农药残留快速检测结果准确。市售蔬菜中存在农药超标:从不同种类来看,瓜菜类农残超标率最高,为9.80%;在7—11月中,11月蔬菜农残超标率最高,为18.29%;从不同取样点来看,农产品商店超标率最高,为12.00%。除部分蔬菜种类,快速检测结果快速且准确。     

如东县蔬菜农药残留例行监测结果与分析

如东县连续3年例行监测蔬菜农药残留情况,共定量检测蔬菜样本1200份,分析研究蔬菜农药残留的状况和农药污染的主要原因。数据分析结果表明,蔬菜样本中农药残留的检出率为14.83%,超标率为4.30%;不合格蔬菜样本主要为韭菜和豇豆,引起蔬菜农残超标的农药主要是有机磷类农药,各类蔬菜农药残留的合格率在每年第3季度最高,合格率有逐年上升趋势。     

近十年内蒙古产地蔬 菜农药残留状况及规律 性分析

对近十年内蒙古主产的6 800 份蔬菜样品的农药残留超标状况进行数理统计分析。结果表明：
内蒙古产地蔬菜主要以绿叶菜类、茄果类和瓜类为主,其产量占蔬菜产量的70%;随着2003 年以来蔬菜
检测数量的逐年增加,内蒙古产地蔬菜质量安全状态从快速下降期、规律波动期进入到了持续稳定阶段,
各种类蔬菜的质量安全水平差异化明显。其中占主产蔬菜55% 的茄果类蔬菜、瓜类和豆类蔬菜农药残留
超标率多年变幅低于2%,平均超标率为1.1%、1.6% 和3.1%,属于质量稳定型蔬菜;占主产蔬菜30% 的
绿叶菜类和白菜类蔬菜农药残留超标率虽呈年度降低趋势,但多年徘徊在7%～10%,属风险主体型蔬菜;
根菜类和甘蓝类蔬菜（占主产蔬菜15%）农药残留超标时间不可预见,超标率在某些年份大于5%,变幅
超过15 个百分点,这部分蔬菜为随机风险型蔬菜。超标的农药相对集中并表现出超标概率风险的种类间
差异。70% 的农药间歇性超标,超标概率低于5%;20% 的传统农药经常超标,超标概率大于30%。有机
磷类和氨基甲酸酯类农药残留超标风险整体呈年度降低趋势,而一些新型含氮类农药、高效拟除虫菊酯类
农药残留超标风险逐年增加。     

蔬菜中拟除虫菊酯类农药残留调查

2011年11月对哈尔滨市的17家超市134份样品进行抽检,分析了三氟氯氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯4种农药在不同种类蔬菜上的残留情况。结果表明:15份蔬菜样品检测出不同种类的菊酯类农药,总检出率为12.67%,超标率为2.98%,检测出问题蔬菜品种主要为绿叶菜类。绿叶菜类氯氰菊酯检出率最高,为16.07%,其次为三氟氯氰菊酯检出率为12.5%。     

蔬菜中农药残留状况调查

对石家庄地区20个蔬菜生产基地和市区4大蔬菜批发市场、20家超市随机抽取的240个蔬菜样品进行农药残留分析。结果表明,所检240份蔬菜中,有机磷的检出率为5.42%,超标率为0%;有机氯和拟除虫菊酯检出率为6.25%,其中2份样品超标,超标率为0.83%。通过调查石家庄地区蔬菜中农药残留情况,表明石家庄地区蔬菜样品的超标率较低,但应加强农药使用管理,确保市民食用蔬菜的安全。     

钦州市蔬菜中有机磷农药毒死蜱残留分析

为了解钦州蔬菜中毒死蜱的残留情况,2011—2017年随机抽检2 968批次蔬菜样品,进行有机磷农药毒死蜱定性、定量残留监测。结果显示:样品中毒死蜱检出229批次,占总体的7.72%,超标41批次,占总体的1.38%。4个季度蔬菜中毒死蜱残留情况相似,但一、四季度毒死蜱超标率明显高于二、三季度。叶菜类蔬菜毒死蜱检出率和超标率均最高,分别为9.97%、2.19%;其次为豆类,其检出率和超标率分别为4.49%、0.56%。在县区基地、批发市场、农贸市场随机抽取的蔬菜样品中,其毒死蜱超标率相近,而超市随机抽取的蔬菜样品情况良好,100%合格。     

利用速测仪与气相色谱对蔬菜中有机磷农药残留检测与分析

利用速测仪RP-420及气相色谱7890A-FPD对一定数量的蔬菜样品进行检测.结果表明:经速测仪检测农药残留超标的20份蔬菜,再经气相色谱检测后有17份蔬菜有农药残留检出,检出率达85％,其中有3份超标,超标率达15％.说明利用速测仪对农贸市场或蔬菜批发市场蔬菜进行初步检测,是很必要的,既可以节省检测时间又可以节省检测费用.同时,相同的蔬菜品种虽经速测仪检测均属农药残留超标品种,但经气相色谱检测后发现其检测结果差异很大,说明利用气相色谱对农药残留超标蔬菜进行再次检测,对保证检测结果的准确性是很重要的.     

上海市松江区蔬菜中有机磷农药残留的现状研究

利用气相色谱法测定了上海市松江区22种蔬菜453份样品中有机磷农药残留量。结果表明,上海市松江区蔬菜中超标率最高的有机磷农药是毒死蜱,超标率为1.8%,主要集中在叶菜类。蔬菜中有机磷农药超标集中在种植散户和农贸市场,蔬菜园艺场和种植大户的蔬菜合格率达100%。     

上海市松江区蔬菜中有机磷农药残留的现状研究

利用气相色谱法测定了上海市松江区22种蔬菜453份样品中有机磷农药残留量.结果表明,上海市松江区蔬菜中超标率最高的有机磷农药是毒死蜱,超标率为1.8%,主要集中在叶菜类.蔬菜中有机磷农药超标集中在种植散户和农贸市场,蔬菜园艺场和种植大户的蔬菜合格率达100%.     

2018年定西市蔬菜中农药残留监测结果分析

为了解定西市蔬菜中农药残留情况以及为食品安全风险性评估提供参考依据，2018年对定西市生产基地、批发市场、农贸市场和超市销售的蔬菜中有机磷类、有机氯、氨基甲酸醋类、拟除虫菊酯类共35种农药残留开展监测。结果显示：在检测的220个蔬菜样品中，基地抽取样品130个，合格率为99.2%；超市抽取样品59个，批发市场抽取样品27个，农贸市场抽取样品4个，合格率均为100%；总体合格率为99.5%，同比提高0.8个百分点。以茄果类蔬菜农药检出率及检出农药种类最高，叶菜类次之。共检出禁限用农药10种、非禁限用农药16种，检出率最高的分别为毒死蜱（3.30%）和氯氰菊酯（8.33%）。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.     

The effect of exposure on landscape scale soil surface temperatures and species distribution models

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r ²) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.