腐植酸是具有中国特色的生物刺激剂

讨论生物刺激剂的定义及技术内涵;以大量事实论证腐植酸是一种具有中国特色的生物刺激剂;并通过大量实践进一步梳理腐植酸对农作物增产提质、对化肥减量增效、对土壤改良修复的作用机制。     

Oviposition stimulants and deterrents regulating differential acceptance ofIberis amara byPieris rapae andP. napi oleracea

Iberis amara (Cruciferae) contains both stimulants and deterrents that are involved in regulating oviposition byPieris rapae andP. napi oleracea. The most active deterrents toP. rapae isolated from butanol extracts of the plant were found to be 2-O--d-glucosyl cucurbitacin I and 2-O--d-glucosyl cucurbitacin E. However,P. napi oleracea was behaviorally insensitive to these compounds and was only weakly deterred by other individual fractions of the butanol extract. Stimulant activity of the postbutanol water extract ofI. amara was associated with glucosinolates. The most abundant of these was identified as sinigrin, and a relatively minor component was shown to be glucoiberin. The isolated sinigrin was more stimulatory toP. rapae than was the glucoiberin-containing fraction, butP. napi oleracea was stimulated as strongly by the glucoiberin fraction, even though the concentration of this compound was much lower. The contrasting responses of the twoPieris species to the deterrents and stimulants inI. amara can explain the differential acceptance of the plant by these butterflies.     

A chemical basis for differential acceptance ofErysimum cheiranthoides by twoPieris species

Wormseed mustard,Erysimum cheiranthoides, is unacceptable as a host for the cabbage butterfly,Pieris rapae. However, it is preferred for oviposition byPieris napi oleracea in the greenhouse. Isolation and identification of the oviposition stimulants toP. napi oleracea were accomplished by C₁₈ open-column chromatography, TLC, ion-exchange chromatography, HPLC, UV, and NMR spectroscopy. Glucoiberin and glucocheirolin were identified as the most active stimulants. The extracted glucoiberin was as stimulatory as glucocheirolin, although its concentration in theErysimum plants was about 10 times lower than that of glucocheirolin. These glucosinolates were only weak stimulants toP. rapae. Furthermore,P. rapae was strongly deterred by the cardenolides, erysimoside and erychroside, fromE. cheiranthoides, andP. napi oleracea was less sensitive to these compounds. No other deterrent toP. napi oleracea was detected in this plant species. The results explain the differential acceptance ofE. cheiranthoides by these twoPieris species.     

A role for affect in context-dependent sensitization to amphetamine.

Repeated exposure to stimulant drugs, such as amphetamine, induces sensitization to their behavioral activating effects. It is commonly assumed that behavioral sensitization is expressed in the environment explicitly paired with the drug but not in a different environment explicitly unpaired with the drug. The experiments reported here show that this assumption is incorrect. It was found that sensitization was expressed in an environment explicitly unpaired with amphetamine, but imbued with positive affective valence by its association with a natural reward, oral sucrose. These results suggest that the affective valence of the environment in which the drug is administered plays a decisive role in the expression of drug effects, regardless of any previous association of that environment with the drug. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of organic solvent extracts from herbage on feeding behavior in goats

The effects of organic solvent extracts from perennial ryegrass (Lolium perenne L. cv. Friend), orchardgrass (Dactylis glomerata L. cv. Akimidori) andLolium ×Festuca hybrid on the hay consumption of goats were measured by simple two-choice feeding assays. Orchardgrass hay treated with methanol extracts (resuspended in water) of perennial ryegrass showed an increased intake by goats compared to untreated hay (P < 0.01). The palatability of hay tended to be slightly decreased by spraying it with pentane extract of perennial ryegrass and orchardgrass. Furthermore, extracts of hybrid with pentane inhibited goats from feeding (P < 0.05). Methanol extract stimulated hay consumption whereas the pentane extracts did not change or reduce intake.     

Pharmacological cognitive enhancers: Comment on Smith and Farah (2011).

Smith and Farah (2011) provided a thought-provoking and perhaps deliberately provocative literature review of the use of stimulants to improve cognitive functioning in humans. They addressed the apparently increasing willingness of individuals mostly in the United States to use stimulants for this purpose and then summarized published literature that explores whether stimulants actually improve specific aspects of neurocognitive function. Although calling for more research, they tentatively concluded that stimulants indeed may be “smart pills” for some people under certain circumstances. This comment emphasizes that they never actually defined the desired qualities of a smart pill, seemed to accept the unproven axiom that slight improvements in specific tests constitute meaningful enhancement of intelligence, and failed to consider the possible costs to individuals and to society of promoting the use of this class of medications for such a purpose. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Behavioral evaluation of modafinil and the abuse-related effects of cocaine in rhesus monkeys.

Modafinil is a central nervous system stimulant used to promote wakefulness, and it is being evaluated clinically as an agonist medication for treating stimulant abuse. This is the first report of the effects of modafinil on the abuse-related effects of cocaine in nonhuman primates. The behavioral effects of modafinil were examined in three studies. First, the discriminative stimulus effects of modafinil (3.2–32 mg/kg) were evaluated in rhesus monkeys (Macaca mulatta) trained to discriminate either low (0.18 mg/kg, IM) or high (0.4 mg/kg, IM) doses of cocaine from saline. Modafinil dose-dependently substituted for cocaine in 6 of 7 monkeys. In the second study, the effects of chronically administered modafinil (32–56 mg/kg/day, IV) on food- and cocaine-maintained (0.001–0.1 mg/kg/inj) operant responding were examined. Modafinil was administered 3 times/hr for 23 hr/day to ensure stable drug levels. Chronic treatment with 32 mg/kg/day modafinil selectively reduced responding maintained by intermediate and peak reinforcing doses of cocaine, but responding maintained by higher doses of cocaine was unaffected. Food-maintained behavior did not change during chronic modafinil treatment. In a third study, modafinil (32 and 56 mg/kg/day, IV) was examined in a reinstatement model. Modafinil transiently increased responding during extinction. These findings indicate that modafinil shares discriminative stimulus effects with cocaine and selectively reduces responding maintained by reinforcing doses of cocaine. In addition, modafinil reinstated cocaine-seeking behavior, which may reflect its cocaine-like discriminative stimulus effects. These data support clinical findings and indicate that these preclinical models may be useful for predicting the effectiveness of agonist medications for drug abuse treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of estradiol and progesterone in modulating the subjective effects of stimulants in humans.

Although stimulant abuse is a growing problem among women, few studies have focused on factors that may be implicated in potential sex differences. Numerous preclinical studies have indicated that female rodents are more sensitive than male rodents to the behavioral effects of stimulants and that the hormone estradiol is involved in these sex differences. In humans, the subjective response to stimulants is greater in the follicular phase (characterized by moderate estradiol levels and minimal progesterone levels) than in the luteal phase (characterized by elevated estradiol levels and elevated progesterone levels). Differences between men and women emerge only when men are compared with women in the luteal phase; the subjective response to stimulants is similar in men and women in the follicular phase. In contrast to rodents, there is minimal evidence that estradiol enhances the subjective response to stimulants in humans. Rather, the hormone progesterone has been shown to attenuate the subjective response to stimulants, particularly in women. Recent preclinical data confirm that progesterone reduces the behavioral response to stimulants. In summary, there is converging evidence from studies in humans that (a) men and women do differ in their subjective response to stimulants; (b) these sex differences are evident when women are in the luteal phase, when progesterone levels are elevated; and (c) progesterone administration attenuates the subjective response to stimulants. Therefore, the menstrual cycle should be addressed in mixed-gender studies. Moreover, the modulatory effects of progesterone on reducing the positive effects of cocaine may have some clinical utility in treating stimulant abusers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Research Advances in Alcohol and Drug Problems.

Reviews the book, Research Advances in Alcohol and Drug Problems edited by Yedy Israel, Frederick B. Glaser, Harold Kalant, Robert E. Popham, Wolfgang Schmidt, and Reginald G. Smart (1981). This book is the sixth volume of the series, Research Advances in Alcohol and Drug Problems. The purpose of this series, as stated by the editors, is not to provide an annual review each year on a fixed selection of topics but rather "to present each year evaluative papers on topics in which enough recent progress has been made to alter the general scope in a particular area." In Volume 6 several chapters deal with highly specialized topics such as: Tolerance to sensitization to central stimulants, brain peptides, liver functions, and mutagenicity of alcohol and tobacco smoke. The prohibitive price $59.50 (U.S. dollars) and highly specialized and diverse nature of many of the chapters in this book, will likely prevent this book from finding its way into many personal libraries. This work would, however, be a worthwhile acquisition for any university or alcohol treatment library. (PsycINFO Database Record (c) 2010 APA, all rights reserved)