全膜双垄沟播玉米密度对产量及植株性状的影响研究

通过在全膜双垄沟播技术模式下6个耐密型玉米杂交种不同密度(4.5、5.25、6.0、6.75、7.5万株·hm^-2)的试验,研究了玉米产量及其性状与种植密度的关系。在本文研究密度范围内,玉米的产量随着密度的增加而增高;当密度达到一定程度之后,随着密度的增加,产量反而下降,二者呈二次曲线模式变化Y=-6417.314+5501.842X-396.330X²。结果表明,6个耐密型玉米杂交种在双垄全膜沟播技术模式下最佳密度为6.941万株·hm^-2。此密度下各植株性状指标为：穗粒数为499.9粒、百粒重为38.63 g、出籽率为83.71%、穗长为17.5 cm、株高194 cm、茎粗2.14 cm、秃顶长1 cm。株高与密度之间为正相关,函数曲线是幂模型Y=140.607X^0.16602,穗粒数、穗粗、茎粗、出籽率4个性状与密度之间为负相关,函数模型均为性状指标随密度的增加而减少的三次曲线。秃顶长、穗长、百粒重与密度的关系呈二次曲线模式变化。密度与秃顶长之间为正相关,与穗长、百粒重之间为负相关。秃顶长随着密度的增大而增加;穗长、百粒重随密度的增加而呈单边下降的变化趋势。穗位高与密度的相关不显著。     

中度盐碱地氮、磷肥对蓖麻生育特性和产量的影响

以淄蓖8号为试验品种,研究了中度盐碱地蓖麻在不同施氮量和施磷量条件下的生长特性、干物质积累、产量构成和产量。结果表明,氮肥、磷肥和两者互作对各时期主茎真叶数的影响不显著,氮肥、磷肥和两者互作从蕾期开始对株高和地上部干重的影响达显著或极显著水平,从苗期开始对叶干重和茎干重的影响达显著或极显著水平,对花序干重的影响达显著或极显著水平;氮肥对每株穗数的影响达到显著水平,磷肥及二者互作的影响未达到显著水平;氮肥、磷肥及二者互作对每穗粒数、百粒重和籽粒产量的影响达到显著或极显著水平;开花期、花后和灌浆成熟期群体地上部干物质积累与籽粒产量均呈显著线性正相关关系,提高开花后干物质的积累有利于籽粒产量的提高。在本试验条件下,施氮量225 kg·hm^-2、施磷量90 kg·hm^-2,苗期和蕾期各施用氮、磷肥的50%获得的籽粒产量最高,达3　568.4 kg·hm^-2。     

北疆春播、麦后复播青贮玉米物质生产和温光生态效应利用的比较--测试文章

以新玉15号为供试品种，研究了春播和麦后复播青贮玉米（复播1期，6月30日播种；复播2期，7月10日播种）在产量、干物质积累和光温气候资源利用等方面的差异。结果表明：春播、复播1期、复播2期的群体干物质产量分别为15 615、17 615、14 671 kg·hm^-2，春播、复播1期、复播2期鲜重产量53 988、67 251、68 327 kg·hm^-2；复播青贮玉米生育期明显缩短，光合有效辐射和≥10℃积温较春播少；复播1期苗期、穗期、灌浆期均处于最适温度范围之内；春播、复播1期、复播2期的LAI峰值为5.01、5.72、6.36，总光合势分别为2.45×10⁶、2.84×10⁶、3.37×10⁶ m²·d^-1·hm^-2。复播青贮玉米的产量潜力主要在于大口期之前生育期优越的光温资源条件，且大口期之前干物质积累速率较春播快。     

屠宰场废弃物堆肥对苜蓿生长和碱化土壤肥力指标的影响

对屠宰场猪、牛、羊废弃物堆肥施入退化土壤后作物生理指标、土壤肥力指标和微生物区系变化进行系统研究。结果表明：施用废弃物堆肥明显提高了苜蓿出苗率，并缩短了出苗时间，但不同种类、不同施用量（22.5 t·hm^-2、30.0 t·hm^-2和37.5 t·hm^-2）废弃物提高的幅度不同。苜蓿鲜生物量随着废弃物施用量的增大而增加，其中羊废弃物施用量为37.5 t·hm^-2的处理最大，为11.95 g·plant^-1，不施用废弃物的处理鲜生物量最小，其最大值为10.26 g·plant^-1；施用猪废弃物30.0 t·hm^-2的处理其干生物量最高（3.91 g·plant^-1）。施用屠宰场废弃物堆肥后土壤有机质及养分都有不同程度的增加，如10月中旬土壤有机质和速效钾含量增幅略低，分别为9.92%～27.12%和5.77%～34.03%，碱解氮和速效磷增幅分别为11.79%～47.66%和16.92%～44.97%。猪废弃物施用量为37.5 t·hm^-2的处理细菌数量在8月底达到3.98×10⁷ cfu·g^-1，羊和牛废弃物相同时期相同用量条件下细菌数量相近，一般废弃物施用量越大土壤中细菌、真菌和放线菌数量也越多。     

磷钾肥对云南旱作马铃薯产量和养分吸收的影响--测试文章

在云南省曲靖地区的低肥力和中高肥力试验地分别开展旱作马铃薯的田间小区试验,研究磷钾施用量对马铃薯生物量、养分利用、产量和经济效益的影响。结果表明：相同施肥量的条件下,中高肥力试验地的东山组马铃薯产量远高于低肥力的越州组,产量相差10 305.00～20 140.20 kg·hm^-2;越州组NP2K3(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 405 kg·hm^-2)处理产量产值最高,NP2K1(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 135 kg·hm^-2)处理净收益最高; 东山组NP2K2(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 270 kg·hm^-2)处理产量、产值及净收益均是最高; 两组试验的马铃薯干重变化趋势相似,NP2K2处理的干重积累量较多,无钾无磷处理干重积累少;马铃薯体内累积K最多,其次为N,最后为P, NPK养分吸收积累的高峰期在马铃薯块茎膨大期到淀粉积累期; 东山组的马铃薯PK利用效率明显高于越州组。NP1K2(N,150 kg·hm^-2; P₂O₅,45 kg·hm^-2; K₂O, 270 kg·hm^-2)处理的P肥利用率和P素农学效率较高,P肥利用率和P素农学效率都有随施P量增加而降低的趋势。NP2K1处理的K肥利用率和K素农学效率最高,K肥利用率和K素农学效率均有随施K量增加而降低的趋势。     

秸秆还田下减量施氮对作物产量及养分吸收利用的影响--测试文章

秸秆还田条件下,采用多年田间定位试验研究了N肥减量施用对作物产量、养分吸收利用以及土壤表观N平衡的影响,旨在为关中小麦/玉米一年二熟轮作区合理施用N肥提供依据。结果表明：与常规施N处理(玉米季施氮187.5 kg·hm^-2,小麦季施氮150 kg·hm^-2)相比,2008—2011年三年中,15%减N、30%减N两个处理均未显著降低作物籽粒与秸秆产量;2010—2011年生长季中,15%减N处理降低了作物秸秆N、P、K周年总吸收量,增加了籽粒N、P、K周年总吸收量,其中籽粒P周年总吸收量增加达显著性水平;30%减N处理显著降低了籽粒N和秸秆N、K周年总吸收量,降幅分别为12.9%、41.9%、18.5%,在小麦收获后,30%减N处理的N素盈余量只有11.3 kg·hm^-2,有潜在缺N危险。综合考虑产量、养分吸收利用及土壤表观N平衡,在秸秆还田条件下,15%减N处理的施N量（即玉米季施氮159 kg·hm^-2,小麦季施氮127.5 kg·hm^-2）为本地区最佳N肥用量。     

施用硅肥对田间春小麦花后源库关系的影响

以两个黑龙江春小麦品种即龙麦26（不耐密）和克旱16（耐密）为材,在田间机播条件下进行不同硅肥用量基施试验,通过测定不同生育期的光合性能、籽粒灌浆速率及产量构成因素,以探明基施硅肥对春小麦源库特性及产量的影响。结果表明,基施硅肥可协调小麦源库关系,使小麦源足、库大。两个春小麦品种施入硅肥后穗长和小穗数增加,千粒重未达到显著水平,硅肥提高了不耐密品种的穗粒数和穗粒重,增加了耐密品种的穗数。不耐密品种龙麦26、耐密品种克旱16的最优硅肥施用量分别为30 kg·hm^-2、60 kg·hm^-2,过多施入硅肥反倒有不利影响。     

不同基因型啤酒大麦品种（系）籽粒灌浆特征及产量性状--测试文章

以9个不同基因型啤酒大麦品种（系）为供试材料，比较了籽粒灌浆特性及产量性状等指标。结果表明：不同基因型啤酒大麦品种（系）籽粒灌浆过程均呈“S”型曲线变化，开花后天数与千粒重的关系均符合Logistic方程，籽粒灌浆速率变化均呈“慢—快—慢”规律；高秆、旗叶宽大的品种（系）粒重增加时间较早；分蘖能力强或旗叶宽大的品种（系）灌浆速率峰值显现较早，且为单峰，其他品种（系）则为双峰；株高、分蘖能力、旗叶适中的品种（系）保持较高灌浆速率的持续时间较长；在各灌浆特征参数中，最大灌浆速率(R_max)与产量的灰色关联度最大，平均灌浆速率(R)与千粒重的灰色关联度最大，起始生长势(C₀)对前期贡献率的灰色关联度最大。旗叶宽大、分蘖能力和抗旱性较强的品种（系）穗长和穗粒重最大，穗粒数最多，具有一定的产量优势，可作为育种选择目标。0110-16和甘啤7号品种（系）单位面积产量较高，可在生产上推广应用。     

不同耕作覆盖措施下延收对春玉米产量及籽粒品质的影响

选用5种耕作覆盖方式和7个采收时期研究延收对籽粒产量、千粒重、籽粒蛋白质、脂肪、淀粉含量及其对应的产出量的影响，为玉米获得高产优质提供依据。结果表明：适时延收可使玉米产量及主要营养成分产出量明显增加，延收15 d，产量增幅为10.19%～15.62%，千粒重增幅为14.70%～20.39%；籽粒蛋白质含量增加0.26%～1.29%，产出量增加117～230 kg·hm^-2；脂肪含量增加0.05%～0.40%，产出量增加54～78 kg·hm^-2；淀粉含量虽然降低0.5%～4.9%，但产出量仍然增加340～773 kg·hm^-2。黄土高原地区春玉米延收15 d具有明显的增产和提高籽粒品质产量的效果，但增幅因耕作和覆盖方式不同而存在差异。     

地膜覆盖对杂交谷子光合特性、产量及水分利用效率的影响

试验在河北省张家口市农科院宣化试验站（115°3′N, 40°63′E）进行,研究了露地平地种植、全膜平铺平地种植、沟植不覆盖地膜、垄膜覆盖膜侧沟植4种种植方式下地膜覆盖对张杂谷3号光合作用等生理特征、产量及水分利用的影响。试验结果表明,地膜覆盖使平播及沟植条件下的籽粒产量分别增加13.25%和6.64%,叶片水势提高0.16 MPa和0.09 MPa,叶片光合速率提高10.87%和15.69%,蒸腾速率提高8.5%和15.95%,气孔导度提高0.0092 mol·m^-2·s^-1和0.0284 mol·m^-2·s^-1,叶片水分利用效率提高13.80%和1.80%。从以上结果得出：(1) 地膜覆盖改善了植株水分状态,叶片水势和叶绿素含量均提高,植株生长旺盛;使叶片的光合等生理活动维持较高水平;植株水分利用效率提升,从而促进了籽粒产量的显著提高; (2) 平播条件下覆膜的增产效果较平地播种、无膜沟植、垄膜沟植更加明显。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.