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1.
Amniotic fluid from smokers and non-smokers was tested by the Salmonella/mammalian microsome test. Concentrated amniotic fluid from heavy smokers at term showed an increase in the number of revertants with increasing exposure to tar. However, some of the non-smokers had a higher number of revertants than the smokers. No significant differences were found between second-trimester samples from smokers and non-smokers, but the limited volumes available at this stage of pregnancy may be a source of error.  相似文献   
2.
The present study examines the feasibility of using the Salmonella typhimurium plate-incorporation assay of Ames for detecting target-organ specificity with N-nitroso-N-methylaniline (NMA), a compound for which the target site for tumour formation in the rat is the oesophagus. Thus it was anticipated that the oesophagus would bioactivate this compound. The compound has been investigated using S9 from Aroclor- and NMA-induced rat oesophagus, salivary gland and liver in the presence and absence of the co-mutagen, norharman. No response to NMA was seen with oesophageal S9 even though benzo[a]pyrene produced a dose-related increase in revertants in strain TA98 and TA100. No response to NMA was seen with salivary-gland S9. However, a response was produced with Aroclor-induced rat-liver S9 in the presence of norharman and with NMA-induced rat-liver S9 in the absence of norharman.  相似文献   
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The identification of a highly selective D2 partial agonist, D3 antagonist tool molecule which demonstrates high levels of brain exposure and selectivity against an extensive range of dopamine, serotonin, adrenergic, histamine, and muscarinic receptors is described.  相似文献   
5.
This report describes the cloning of recombinant human Bcl-2, in which the putative disordered loop region has been replaced with a flexible linker and the hydrophobic C-terminus has been replaced with a 6xHis tag (Bcl-2(6-32)-AAAA-Bcl-2(86-206)-HHHHHH, abbreviation rhBcl-2; amino acid numbering excludes the initiating methionine). This protein was expressed in Escherichia coli where it accumulated in insoluble form in inclusion bodies. After lysis the washed inclusion bodies were solubilized and an l-arginine assisted protein refolding route was employed to obtain biologically active protein. rhBcl-2 was purified further by nickel chelate chromatography to give protein of >95% purity, with an overall yield of 5 mg per g of E. coli cell paste. Edman sequencing showed that approximately 90% of the rhBcl-2 retained the initiating methionine residue. Analytical size exclusion chromatography suggested that the refolded and purified rhBcl-2 was monomeric in nondenaturing solution. Purified protein had an affinity for a Bax BH3 domain peptide comparable to that for in vivo folded recombinant human Bcl-2 and suppressed caspase activation in a cell-free assay for apoptosis. 1H NMR spectroscopy of rhBcl-2, both free and complexed with the Bax BH3 domain peptide, provided further evidence for the structural and functional integrity of the refolded protein. These findings parallel and extend those of Muchmore et al., who found that a loop deletion mutant of human Bcl-XL retained anti-apoptotic function.  相似文献   
6.
To determine whether large DNA molecules could be transferred and integrated intact into the genome of plant cells, we bombarded tobacco suspension cells with yeast DNA containing artificial chromosomes (YACs) having sizes of 80, 150, 210, or 550 kilobases (kb). Plant selectable markers were retrofitted on both YAC arms so that recovery of each arm in transgenic calli could be monitored. Stably transformed calli resistant to kanamycin (300 mg/L) were recovered for each size of YAC tested. Two of 12 kanamycin-resistant transformants for the 80 kb YAC and 8 of 29 kanamycin-resistant transformants for the 150 kb YAC also contained a functional hygromycin gene derived from the opposite YAC arm. Southern analyses using probes that spanned the entire 55 kb insert region of the 80 kb YAC confirmed that one of the two double-resistant lines had integrated a fully intact single copy of the YAC DNA while the other contained a major portion of the insert. Transgenic lines that contained only one selectable marker gene from the 80 kb YAC incorporated relatively small portions of the YAC insert DNA distal to the selectable marker. Our data suggest genomic DNA cloned in artificial chromosomes up to 150 kb in size have a reasonable likelihood of being transferred by biolistic methods and integrated intact into the genome of plant cells. Biolistic transfer of YAC DNA may accelerate the isolation of agronomically useful plant genes using map-based cloning strategies.  相似文献   
7.
The identification and subsequent optimisation of a selective non-peptidic NPY Y2 antagonist series is described. This led to the development of amine 2, a selective, soluble NPY Y2 receptor antagonist with enhanced CNS exposure.  相似文献   
8.
Two C4 plants, Miscanthus x giganteus and Cyperus longus L., were grown at suboptimal growth temperatures and the relationships between the quantum efficiencies of photosynthetic electron transport through photosystem II (PSII) (PSII operating efficiency; Fq'/Fm') and CO2 assimilation (phiCO2) in leaves were examined. When M. x giganteus was grown at 10 degrees C, the ratio of the PSII operating efficiency to phiCO2 increased relative to that found in leaves grown at 14 and 25 degrees C. Similar increases in the Fq'/Fm': phiCO2 occurred in the leaves of two C. longus ecotypes when the plants were grown at 17 degrees C, compared to 25 degrees C. These elevations of Fq'/Fm': phiCO2 at low growth temperatures were not attributable to the development of anthocyanins, as has been suggested for maize, and were indicative of the operation of an alternative sink to CO2 assimilation for photosynthetic reducing equivalents, possibly oxygen reduction via a Mehler reaction, which would act as a mechanism for protection of PSII from photoinactivation and damage. Furthermore, in M. x giganteus grown at 10 degrees C, further protection of PSII was effected by a 20-fold increase in zeaxanthin content in dark-adapted leaves, which was associated with much higher levels of non-photochemical quenching of excitation energy, compared to that observed in leaves grown at 14 and 25 degrees C. These differences may explain the long growing season and remarkable productivity of this C4 plant in cool climates, even in comparison to other C4 species such as C. longus, which occur naturally in such climates.  相似文献   
9.
Large flying foxes (Pteropus vampyrus) are a socially complex species. In situ colonies typically comprise thousands of individuals in small harems of one male to many females. In ex situ environments, all‐male colonies are becoming more common due to a surplus of males in the population. There is limited information describing the hormonal and behavioral patterns of all‐male colonies during the breeding season. We assessed seasonal changes in hormones and behavior in an all‐male colony of 12 large flying foxes at Disney's Animal Kingdom®. We validated hormone assays using morning urine and fecal samples to assess seasonal changes in excreted immunoreactive testosterone and glucocorticoid metabolites. We collected behavior data using an all‐occurrence method, recording agonistic behaviors related to territorial defense (hooking, biting, wing flexing, vocalizing, and wrestling), and sexual behavior (mounting and frontal grabbing). Results indicated that (i) we could reliably measure testosterone and glucocorticoid metabolites concentrations from fecal and urine samples collected from individual bats; (ii) there were distinct relationships between changes in levels of agonism and hormone concentrations throughout the year; and (iii) three agonistic behaviors (chasing, wrestling, and open‐mouth threat) peaked prior to the increase in testosterone and glucocorticoid hormones measured during the breeding season. These three behaviors could potentially be used as early indicators to signal the onset of the breeding season and allow time to implement ex situ management changes to reduce the incidence of agonism between individuals.  相似文献   
10.

Purpose

In 2012 and 2013, the University of Arizona’s Office of Sustainability conducted environmental life cycle assessments of two Homecoming events that drew 60,000 attendees each. Based on reviews of published literature, this is the first time that a process-based life cycle assessment has been conducted for an event of this size. This study contributes to the small but growing field of research using life cycle assessment to track the environmental impacts of events.

Methods

The assessments at The University of Arizona considered the environmental impact of food, materials, waste, travel, and lodging. The effects of these components of Homecoming weekend were evaluated in terms of nine different categories. However, this paper focuses on greenhouse gas emissions. The data collection process for these assessments was completed by student observers and supplemented with information provided by university departments, event organizers, and survey responses from attendees. Data were analyzed using SimaPro Life Cycle Assessment software and using data from the EcoInvent database. Based on the results of the 2012 study, initiatives were put into place for 2013 that were designed to reduce the environmental impact of the subsequent Homecoming event.

Results and discussion

The results show that the total impact of Homecoming 2012 was an estimated 2400 metric tons of CO2-eq, whereas the impact of Homecoming 2013 was an estimated 1900 metric tons of CO2-eq, a 19 % decrease year over year. Data were analyzed in terms of carbon dioxide emissions in both years. Travel made up the majority of the environmental impact (82.04 % in 2012 and 77.77 % in 2013), followed by accommodations (17.5 % in 2012 and 19.31 % in 2013), with energy, materials, and food having almost negligible impacts (0.46 % in 2012 and 2.92 % in 2013). While there had been noticeable changes in the measured impact of food and energy between 2012 and 2013, the significant impact of travel overshadowed all other impact categories in terms of greenhouse gas emissions, making these changes less noticeable. Analysis of each of these categories of impact helped to establish best practices for mitigating the impact of events on a category-by-category basis.

Conclusions

This study introduces a framework for assessing impacts of a large university event while also highlighting ways to reduce impacts. The initiatives implemented in 2013 to reduce impacts of large-scale events can be informative to others working to reduce emissions at large events. Additional recommendations to reduce impacts of large events are provided.
  相似文献   
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