新昌县蔬菜农药残留监测分析

对新昌县生产基地和农贸市场随机采集的共246份蔬菜样本进行了农药残留检测,检测有机磷类、有机氯类、拟除虫菊酯类和氨基甲酸酯类农药残留22项。结果表明,检出农药残留样本36份,总检出率为14.6%,农药超标样本4份,总超标率为1.6%。第三季度蔬菜的农药残留全年最高,检出率和超标率分别为22.1%和4.4%。不同种类的蔬菜农药残留检出率排序为叶菜类豆类芸薹属类根茎类茄果类瓜菜类薯芋类葱蒜类,仅叶菜类、瓜菜类和茄果类农药残留超标。由此表明,新昌县蔬菜农药残留依然存在,少数蔬菜中农药残留超标,应加大监测管理力度,确保市民食用蔬菜安全。     

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%）。     

分光光度法快速检测蔬菜、水果中的拟除虫菊酯类农药总量

严格控制蔬菜、水果中的农药残留含量是保障人们身体健康的重要手段。目前,国内对毒害性较大的有机磷、氨基甲酸酯类农药的测定已经有了成熟的快速检测方法（酶抑制率法）,而拟除虫菊酯类农药由于对酶的活性不敏感,所以还没有出现这类农药的速测方法。拟除虫菊酯类农药的毒性虽然没有有机磷、氨基甲酸酯类农药大,     

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。     

钦州市散户种植叶菜类蔬菜农药残留调查分析

利用气相色谱仪对钦州市散户生产的198份叶菜类蔬菜中的30种有机磷、有机氯及拟除虫菊酯类农药残留情况进行了定性定量检测。结果表明:检测的30种农药中有16种在蔬菜中不同程度被检出,其中,毒死蜱的检出次数最多,其次是三唑酮和百菌清;还检出了禁用农药水胺硫磷。因此,钦州市散户叶菜类蔬菜农药残留仍然较为普遍;散户科学合理用药意识还有待进一步提高。     

安全使用“敌杀死”

<正> 敌杀死是2.5％溴氰菊酯乳剂的商品名称。是拟除虫菊酯类农药中的一种,它具有杀虫活性强、杀虫谱广、低残留、在环境中分解较快等特点,是一种高效低毒较为先进的农药品种。近二年来,已在棉花、果树、蔬菜以及其他特种经济作物上广泛使用。     

陕西苹果主产区果实农药残留水平及其评价

2003～2005年连续3年对陕西20个苹果基地县的农药残留状况采用GC和HPLC方法进行了监测,并以国家规定的苹果农药最大残留限量进行了评价。结果表明,陕西苹果的农药检出率为48.6％,样品农药检出率为93.6％。检出率2%以上的农药依次为多菌灵（89.5％）、甲氰菊酯（18.7％）、六六六（16.7％）、氯氰菊酯（15.7％）、氰戊菊酯（13.4％）、乐果（11.5％）、溴氰菊酯（11.2％）、滴滴涕（9.0％）、三氟氯氰菊酯（6.7％）、百菌清（5.8％）、异菌脲（5.3％）、毒死蜱（3.8％）、敌敌畏（2.3％）、氟氯氰菊酯（2.2％）和克菌丹（2.1％）。超标的农药有多菌灵（9.50％）、敌敌畏（1.54％）、辛硫磷（0.77％）和氰戊菊酯（0.75％）;经单项农药污染指数、污染指数≥0.5的样品比率、检出率、超标率的综合评价发现,陕西苹果主要污染农药为杀菌剂中的多菌灵,拟除虫菊酯类的甲氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯和有机磷农药中的敌敌畏。     

蔬菜农药残留监测结果与发展对策

蔬菜作为人们每天必不可少的食用农产品,其农药残留超标问题,直接影响到人民的身体健康,已引起了各级政府的高度重视和全社会的广泛关注.温岭市农产品质量检验监督站从2002年开始在蔬菜病虫害发生比较普遍、用药比较频繁的5～11月份,对全市主要无公害蔬菜生产基地以及太平街道菜市场的蔬菜开展了全面、系统的农药残留监测工作.2002～2003年对抽检的样品先通过速测筛选,对速测不合格的样品再进行气相色谱定量检测,确定其残留超标的农药品种和残留量;2004年,针对速测仪器只能检测蔬菜中氨基甲酸酯类和有机磷农药是否超标,而难于检测蔬菜生产上使用比较普遍的拟除虫菊酯类农药的残留量是否超标的问题,在对所有抽检的蔬菜样品通过速测的同时,均进行气相色谱定量检测.本文现就我市蔬菜农药残留的检测状况、存在问题与发展对策进行剖析,供参考.     

蔬菜农药残留的危害性及超标原因分析

文章主要探讨蔬菜中机磷类、有机氯类、氨基甲酸酯类及拟除虫酯类等常见4类代表性农药残留的危害性,并分析引起蔬菜农药残留超标的主要原因。     

龙湾屯苹果质优价高

<正>日前,由北京市顺义区农药管理站利用现代安捷伦气相色谱仪对龙湾屯镇的两个果品合作社和部分采摘园的梨、苹果等96份抽样果品进行的检测结果显示:有机磷、拟除虫菊酯类农药等残留均未超标,合格率为100%。     

Ergebnisse der Leistungsprüfungen der Süßkirschensorte ‚Stella‘ auf Gisela- und Weiroot-Unterlagen in Bulgarien

Zusammenfassung Die Leistungsprüfungen wurden im Zeitraum 1997 bis 2003 mit den Unterlagen Gisela 4 und 5, den Klonnummern 195/20 und 497/8 aus der Gisela-Serie sowie Weiroot 10, 13, 53, 72 und 158 durchgeführt. Dabei dienten Sämlinge von P1 (bulgarische Selektion aus Prunus mahaleb) als Kontrolle. Alle Unterlagen waren mit der Sorte Stella veredelt und im Dezember 1996 in der Versuchsanlage der Agraruniversität in Plovdiv, Bulgarien, im Abstand von 6 m×4,5 m gepflanzt worden. Dabei erfolgte ein Pflanzschnitt. Nach Abschluss der natürlichen Kronenentwicklung wurde jedes Jahr ein Winterschnitt vorgenommen. Der Boden wurde durch mechanische Bearbeitung offen gehalten und nach dem 4. Standjahr wurden die Baumstreifen mit Herbiziden behandelt. Die Wasserversorgung erfolgte durch eine dem natürlichen Gefälle folgende Überflutung, allerdings nicht immer zum optimalen Zeitpunkt, da keine eigene Wasserquelle zur Verfügung stand.Basierend auf den Ergebnissen bis zum Anfang des 7. Standjahres können die untersuchten Unterlagen in zwei Gruppen differenziert werden: starkwüchsig—Weiroot 10, P1 und Weiroot 13; mittelstarkwachsend bis schwachwüchsig—Gi 497/8, Gisela 4, Weiroot 53, Weiroot 158, Gi 195/20, Weiroot 72 und Gisela 5. Letztere zeichnete sich durch besondere Schwachwüchsigkeit aus. Die meisten Wurzelschosser bildeten Gisela 4, Weiroot 10 und Weiroot 13. Weiroot 53, Weiroot 72 und Weiroot 158 entwickelten deutlich weniger und P1, Gisela 5, Gi 195/20 sowie Gi 497/8 keine Wurzelschosser. Den frühesten Blühbeginn induzierte Gisela 4. Die anderen Unterlagen führten, in Abhängigkeit von den Temperaturbedingungen des jeweiligen Jahres, zu einer Verspätung der Blüte: P1 und Weiroot 10 um 1–2 Tage; Gi 497/8, Weiroot 13 und Weiroot 158 um 2–4 Tage; Weiroot 72 um 2–7 Tage; Gi 195/20 um 3–6 Tage; Weiroot 53 um 3–8 Tage und Gisela 5 um 3–10 Tage. Die Reifezeit der Früchte war bei den Bäumen auf Gisela 5 im Vergleich zu den anderen Varianten um 2–3 Tage verspätet. Gisela 5, Weiroot 72 und Gisela 4 induzierten bei der aufveredelten Sorte die höchsten Ertragsleistungen, P1 die geringsten. Bei den Bäumen auf Gisela 5 war die Fruchtgröße geringer als bei den anderen Unterlagen. Bäume auf Gisela 5 brauchen intensive Pflege. Nur wenn alle Produktionsfaktoren und kulturtechnischen Maßnahmen optimiert werden, kann das hohe Ertragspotenzial dieser Unterlage ausgeschöpft werden.     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

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.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

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.     

Effect of puerarin on pulmonary arterioles wall collagen metabolism of chronic hypoxia hypercapnia rats

AIM:To investigate the effect of puerarin on pulmonary vessel collagen metabolism in pulmonary hypertension rats induced by chronic hypoxia and hypercapnia.METHODS:Collagen Ⅰ, Ⅲ and their mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization.RESULTS:① Light microscopy showed media thickness of pulmonary arterioles was much higher in HH(hypoxic-hypercapnia) group than that of NC(normal control) group, and, vessel cavity turned more straiter in HH group than that of NC group.However, the damage of pulmonary arterioles in HP(hypoxic-pueratin) group was much slighter than that of HH group. ② The levels of plasma ET-1 and lung homogenates Hyr were much higher in HH group than those of NC group(P＜0.01), and lower in HP group than HH groups(P＜0.01).Plasma NO content in group HH was lower than that of group NC(P＜0.01), it was higher in group HP than that of group HH(P＜0.01).③Expression of collagen Ⅰ and collagen Ⅰ mRNA in pulmonary arterioles were significantly higher in HH groups than those of NC group (P＜0.01), and they were lower in HP group than those of HH group (P＜0.01).Expression of collagen Ⅲ and collagen Ⅲ mRNA showed no difference among three groups(P＞0.05).CONCLUSION:Puerarin inhibited the deposition of collagen and improved pulmonary vessel remodeling.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

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.     

Multi-scale landscape and seascape patterns associated with marbled murrelet nesting areas on the U.S. west coast

Habitat for wide-ranging species should be addressed at multiple scales to fully understand factors that limit populations. The marbled murrelet (Brachyramphus marmoratus), a threatened seabird, forages on the ocean and nests inland in large trees. We developed statistical relationships between murrelet use (occupancy and abundance) and habitat variables quantified across many spatial scales (statewide to local) and two time periods in California and southern Oregon, USA. We also addressed (1) if old-growth forest fragmentation was negatively associated with murrelet use, and (2) if some nesting areas are more important than others due to their proximity to high quality marine habitat. Most landscapes used for nesting were restricted to low elevation areas with frequent fog. Birds were most abundant in unfragmented old-growth forests located within a matrix of mature second-growth forest. Murrelets were less likely to occupy old-growth habitat if it was isolated (> 5 km) from other nesting murrelets. We found a time lag in response to fragmentation, where at least a few years were required before birds abandoned fragmented forests. Compared to landscapes with little tono murrelet use, landscapes with many murrelets were closer to the ocean's bays, river mouths, sandy shores, submarine canyons, and marine waters with consistently high primary productivity. Within local landscapes (≤ 800ha), inland factors limited bird abundance, but at the broadest landscape scale studied (3200 ha), proximity to marine habitat was most limiting. Management should focus on protecting or creating large, contiguous old-growth forest stands, especially in low-elevation areas near productive marine habitat. This revised version was published online in July 2006 with corrections to the Cover Date.