Viviparous leaves produced by somatic activation of an inactive cytokinin-synthesizing gene

Tobacco plants that are somatic mosaics for expression of a cytokinin-synthesizing gene have viviparous leaves. Such a formation of shoots in an abnormal position represents a significant deviation from the usual organization of the plant body where a central axis produces shoots only in the axils of lateral leaf appendages and according to a precise phyllotactic pattern. This report links vivipary to the expression of a gene whose product is involved in the synthesis of the phytohormone cytokinin.     

Fixation produced by conflict

All rats given a choice between a rewarded alternative and a conflict alternative (rewarded and punished) developed position fixations when the position of the alternatives was reversed. In contrast, all animals given one rewarded alternative and another nonrewarded (or punished and nonrewarded) alternative learned to choose the rewarded side during 25 successive reversals.     

栀子红的生物转化

研究了以栀子黄生产副产物京尼平苷洗脱液生物转化栀子红的反应过程,研究表明反应过程伴随着葡萄糖的水解游离,当葡萄糖不再增加,反应即告结束。在10L的发酵罐中进行栀子红的酶转化,工艺条件为：反应温度50℃,灭酶温度100℃;反应时间18h;搅拌转速80r/min;溶氧控制在低的水平;反应过程伴随栀子红的生成pH由初始的4.50上升到4.68。10L发酵罐中生成的栀子红用大孔吸附树脂精制,得到色价为62.8（E1cm1%,532nm）的栀子红粉末。     

Esters produced by Chalaropsis thielavioides

Chalaropsis thielavioides, a filamnentous fungus. produces a characteristic ester-like aroma on potato dextrose broth. By gas-liquid chromatographic techniques, the major aroma-producing substances have been identified as isobutyl and ethyl acetate. Lesser amounts of isoamyl acetate, ethanol, and methanol were also present.     

Leukotactic factor produced by sensitized lymphocytes

Lymph node lymphocytes obtained from guinea pigs exhibiting delayed hypersensitivity are stimulated in vitro by specific antigen to produce a soluble factor that is chemotactic in vitro for mononuclear macrophages. The material is nondialyzable, relatively heat stable, and elutes from Sephadex G-100 in the fraction containing molecules smaller than immunoglobulins.     

Cataracts produced in rats by yogurt

Rats kept on an exclusive diet of yogurt avidly ate the yogurt, grew at a normal rate, were normally active, mated, conceived, and gave birth to normal, healthy litters. However, all of the rats developed cataracts. Cataracts appeared in young rats 2 to 3 months, and in adult rats 4 to 6 months, after initiation of the yogurt diet. Cataracts first manifested themselves in small vacuoles at the periphery of the lens and then in small striae extending toward the center of the lens. These striae progressively became longer, more coarse, and numerous until they coalesced, finally forming a mature white lens. The high content of galactose in commercially available yogurt could account in full for appearance of cataracts in 100 percent of the experimental animals. The cataracts appear to be the same as those produced by diets with a high content of galactose.     

改性氧化石墨烯对水中亚甲基蓝的吸附特性

为了解决氧化石墨烯(GO)吸附污染物后难以从水溶液中分离的问题,采用聚乙烯亚胺(PEI)对GO进行改性,制备PEI-GO复合材料,并采用红外光谱仪、拉曼、扫描电镜和能谱仪等对复合材料进行结构和形貌表征。分析不同吸附时间、吸附剂用量对亚甲基蓝(MB)吸附性能的影响,并对其采用动力学及温线模型进行拟合,记录GO吸附MB与PEI-GO吸附MB后从溶液中的分离时间。结果表明,PEI-GO复合材料具有良好的二维纳米结构,纳米片层中的含氧官能团与PEI中的氨基反应生成O=C-NH共价键。复合材料PEI-GO对MB具有良好的吸附性能。在MB初始质量浓度为25 mg/L,PEI-GO投入量为30 mg的条件下,PEI-GO的吸附量可达204.87 mg/g;吸附规律符合准二级动力学模型以及Freundlich等温模型;吸附后,分离速率较GO吸附后快4~5倍。     

萼状粒毛盘菌多糖的生物活性

研究萼状粒毛盘菌YM-262胞内、胞外多糖对亚硝基的清除作用、对丙二醛生成的抑制作用、对线粒体的保护作用和抗炎作用。结果表明:胞内、胞外多糖质量浓度为1.2g·L-1时对亚硝酸盐的清除率可达最大,分别为63.21%和52.43%;胞内、胞外多糖均能显著抑制肝匀浆在自氧化和诱导氧化中丙二醛的生成,抑制率分别为32.81%和36.46%;此外,YM-262多糖可抑制.OH所致的氧化损伤,减轻线粒体膜肿胀度,且胞内多糖的抑制率大于胞外多糖;胞内多糖和胞外多糖均可显著抑制二甲苯所致的小鼠耳廓肿胀,减少左右耳质量差,且具有一定的剂量-效应关系,胞内多糖和胞外多糖剂量为400mg.kg-1时,抑制率分别为56.68%和51.87%。     

Retrograde amnesia produced by intraperitoneal injection of physostigmine

Intraperitoneal injection of physostigmine in rats produced a retrograde amnesia of a trained task of escaping shock. This amnesic effect was a U-shaped function of the length of the interval between initial training and injection. In all cases, retraining Occurred 30 minutes after injection. A substantial effect was produced by physostigmine if its application was made 30 minutes after training; there was no effect if application and tests were made 1, 2, or 3 days after the original training. When the substance was injected and the rats were retrained 5, 7, or 14 days after the original training, a substantial effect again appeared. These results are similar to those reported in experiments in which another anticholinesterase, diisopropyl fluorophosphate, was applied intracerebrally. The data demonstrate a similar pattern of change of the amnesia with time, and they substantiate the view that neither the place of application nor the brain lesions caused the reported amnesia.     

Evidence of sea spray produced by bursting bubbles

Measurements of air bubbles and sea spray are compared, showing that bubble bursting is the major mechanism for producing spray.     

Permanence of retrograde amnesia produced by electroconvulsive shock

The permanence of retrograde amnesia produced for a single training trial by a single electroconvulsive shock was studied. No recovery from amnesia was found with either single or repeated retention tests. Amnesic effects were found to be permanent with retention intervals as long as 1 month.     

Retrograde amnesia produced by hippocampal spreading depression

Injection of potassium chloride into the hippocampus produces a disruption of electrical activity; a concomitant of this disruption is a deficit in retention of conditioned suppression learned 24 hours before injection.     

Crystallographic orientation of clinoenstatite produced by deformation of orthoenstatite

Uniaxial compression at 800 degrees C and 5 kilobars confining pressure of a specimen cored from a single crystal of orthoenstatite [(Mg,Fe)SiO(3)] produced fine lamellae 100 to 1000 angstroms thick of untwinned clinoenstatite. The two phases are joined along (100) planes and have b and c axes in common. The orientation of the clinoenstatite a axis contradicts several previously suggested transformation mechanisms and reduces the set of possible mechanisms by a factor of 2.     

Restoration of photographs by neutron activation

Badly faded or stained photographs or radiographs, negative or positive, can be restored by use of neutron activation and autoradiography, provided that at least a trace of image silver is present and that the picture is relatively free of halogens and other silver.     

Effects of serotonin on memory impairments produced by ethanol

Subjects treated with low or high doses of ethanol demonstrated impaired memory, particularly in tests involving the recall of poorly learned information. Zimelidine, an inhibitor of serotonin reuptake, reversed this ethanol-induced impairment. The serotonin neurotransmitter system may mediate learning and memory in humans and may determine some of the effects of alcohol on higher mental functions.     

ATM activation by oxidative stress

The ataxia-telangiectasia mutated (ATM) protein kinase is activated by DNA double-strand breaks (DSBs) through the Mre11-Rad50-Nbs1 (MRN) DNA repair complex and orchestrates signaling cascades that initiate the DNA damage response. Cells lacking ATM are also hypersensitive to insults other than DSBs, particularly oxidative stress. We show that oxidation of ATM directly induces ATM activation in the absence of DNA DSBs and the MRN complex. The oxidized form of ATM is a disulfide-cross-linked dimer, and mutation of a critical cysteine residue involved in disulfide bond formation specifically blocked activation through the oxidation pathway. Identification of this pathway explains observations of ATM activation under conditions of oxidative stress and shows that ATM is an important sensor of reactive oxygen species in human cells.