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61.
62.
The aim of this study was to investigate the development of microcells in the human sarcoma cell line HT-1080 after interference with thiophosphamidum. We found that damaged interphase macrocells located at the projection of the nucleolus may form one or several microcells. The micronuclei of the microcells intensively incorporate the thymidine analogue 5-bromo-2'-deoxyuridine and strongly express argyrophilic nucleolar organiser region proteins. At an early phase of the development, the micronuclei contain fragmented DNA, but in subsequent phases, the micronuclei accumulate polymeric DNA, simultaneously with an increase in their size. After desintegration of the damaged macrocell, the microcells appear in the intercellular space. The microcells can enter mitosis and they strongly express the lung resistance protein. Electron microscopic observations suggest that coiled bodies are involved in the development of the microcells. Since the observed path of microcell formation differs from apoptotic cell fragmentation into apoptotic bodies, we propose a new term for this microcell development: sporosis. We suggest that self-renewal of the tumour stem cells is likely based on sporosis.  相似文献   
63.
Animal populations are becoming increasingly exposed to human activity as human populations expand and demand for energy resources (e.g., coal, oil and natural gas) increases. We initiated this study to document survival and cause-specific mortality patterns of female Rocky Mountain elk (Cervus elaphus) exposed to increasing levels of human activity. We fitted 184 females with VHF or GPS collars over 4 years and used the Kaplan–Meier survival estimator to calculate annual survival rates. We used multinomial logistic regression to assess differences in cause-specific mortality and generalized linear mixed models to determine how probability of survival was structured during hunting season; both analyses examined a suite of 5 covariates (i.e., age, year, extent of space use, cover, and human footprint) as potentially influencing cause-specific mortality and survival probability. Annual probability of survival averaged 0.8 (±0.02 SE) over 4 years but averaged 0.91 (±0.03 SE) when harvest mortality was excluded, which was the most significant source of mortality in most years ( [`(x)] = 0.13 ±0.02 \textSE \bar{x} = 0.13 \pm 0.02\,{\text{SE}} ). We found no difference between cause-specific mortality sources relative to elk that survived during the hunting season (χ 102 = 5.79, P = 0.832). The probability of a female surviving during hunting season was negatively influenced by age, year, extent of space use, cover, and human footprint. We found evidence that human activity may have influenced annual rates of natural survival (i.e., exclusive of hunting mortality) and probability of survival during the hunting season. We note that this study occurred largely on privately owned and managed residential and ranch land and focused on female elk; we acknowledge that survival rate and cause-specific patterns of mortality may vary as a function of land ownership (private vs. public), demographic status, and management and harvest practices. While temporal and spatial scales of 1 week may be sufficient to describe patterns of direct mortality during hunting season, broad temporal or spatial scale analyses may be needed to address natural mortality during other seasons.  相似文献   
64.
65.
High-dose chemotherapy of patients with haematological malignancies results in extracellular iron accumulation and appearance of non-transferrin-bound iron, which is thought to predispose the patients to septic infections and contribute to organ toxicity. We describe the development of a human plasma-derived apotransferrin product for iron binding therapy. The product is purified from Cohn fraction IV of human plasma by two ion exchange chromatography steps and ultrafiltration. The process comprises solvent detergent treatment as the main virus inactivation step and 15 nm virus filtration and polyethylene glycol precipitation as removal steps for physico-chemically resistant infectious agents. Product characterization by electrospray and MALDI-TOF mass spectrometry indicated no other chemical modifications than N-linked glycan chains and disulphide bonds, except minor oxidation. The purity of the product was more than 98%, main impurities being IgG, IgA and hemopexin. The product had intact iron binding capacity and native conformation. A stable liquid formulation for the finished product was developed. The product has proved safe and well tolerated in early clinical trials in iron binding therapy.  相似文献   
66.

Background

The major contribution to oxidant related lung damage in COPD is from the oxidant/antioxidant imbalance and possibly impaired antioxidant defence. Glutathione (GSH) is one of the most important antioxidants in human lung and lung secretions, but the mechanisms participating in its homeostasis are partly unclear. Glutathione-S-transferase omega (GSTO) is a recently characterized cysteine containing enzyme with the capability to bind and release GSH in vitro. GSTO has not been investigated in human lung or lung diseases.

Methods

GSTO1-1 was investigated by immunohistochemistry and Western blot analysis in 72 lung tissue specimens and 40 sputum specimens from non-smokers, smokers and COPD, in bronchoalveolar lavage fluid and in plasma from healthy non-smokers and smokers. It was also examined in human monocytes and bronchial epithelial cells and their culture mediums in vitro.

Results

GSTO1-1 was mainly expressed in alveolar macrophages, but it was also found in airway and alveolar epithelium and in extracellular fluids including sputum supernatants, bronchoalveolar lavage fluid, plasma and cell culture mediums. The levels of GSTO1-1 were significantly lower in the sputum supernatants (p = 0.023) and lung homogenates (p = 0.003) of COPD patients than in non-smokers.

Conclusion

GSTO1-1 is abundant in the alveolar macrophages, but it is also present in extracellular fluids and in airway secretions, the levels being decreased in COPD. The clinical significance of GSTO1-1 and its role in regulating GSH homeostasis in airway secretions, however, needs further investigations.  相似文献   
67.
The formerly endangered Kirtland's warbler (Setophaga kirtlandii) is among a growing number of conservation-reliant species that depend on active management to avoid reverting to endangered status. Because the Kirtland's warbler is a habitat specialist of young, even-aged jack pine (Pinus banksiana), managers of the recovery effort stressed creating new jack pine stands and monitoring numbers of singing males through an annual census using single visits to individual stands. Kirtland's warbler will occupy and breed in red pine (P. resinosa), but red pine has not been surveyed for Kirtland's warblers in the annual population census. Furthermore, the current monitoring approach cannot determine their species detection probability or individual detection probability, which is essential to evaluate both red pine use and the accuracy of the census. From 2016–2018 we estimated density and detection probabilities in jack pine and red pine stands through repeated visits to a limited number of stands rather than single visits to many stands. Estimates of species detection probability indicated that ≥1 male Kirtland's warbler would be detected on most sites when any were present, but individual detection probabilities were less and varied by stand type, indicating that single visits to sites would underestimate numbers and that accurate estimation of detection probability was important for estimation of density in different stand types. We offer quantitative estimates of detection probabilities for determination of Kirtland's warbler population size in jack pine versus red pine stands in the same areas and breeding seasons. Managers of Kirtland's warblers should incorporate detection probabilities into population surveys to achieve more accurate estimates of population size.  相似文献   
68.
The content of assimilable organic carbon has been proposed to control the growth of microbes in drinking water. However, recent results have shown that there are regions where it is predominantly phosphorus which determines the extent of microbial growth in drinking waters. Even a very low concentration of phosphorus (below 1 μg of P liter−1) can promote extensive microbial growth. We present here a new sensitive method to determine microbially available phosphorus concentrations in water down to 0.08 μg of P liter−1. The method is a bioassay in which the analysis of phosphorus in a water sample is based on maximum growth of Pseudomonas fluorescens P17 when the energy supply and inorganic nutrients, with the exception of phosphorus, do not limit bacterial growth. Maximum growth (CFU) in the water sample is related to the concentration of phosphorus with the factor 373,200 ± 9,400 CFU/μg of PO4-P. A linear relationship was found between cell growth and phosphorus concentration between 0.05 to 10 μg of PO4-P liter−1. The content of microbially available phosphorus in Finnish drinking waters varied from 0.1 to 10.2 μg of P liter−1 (median, 0.60 μg of P liter−1).  相似文献   
69.
Compost windrows for bioremediation of soil were built at a wood-preserving site contaminated with chlorophenols, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). Sampling of airborne particles during the mixing of the compost windrows found concentrations of PCDDs and PCDFs in different particle sizes. The congener distribution of PCDDs and PCDFs in the collected air particle fractions was similar to that in the compost windrows, and the level of PCDDs and PCDFs was 1000-fold higher than the atmospheric background values reported previously. Viable particle-sizing samplers and several selective growth media were used to enumerate bacteria and fungi in the airborne particles. From the collected air samples, 40 bacteria were isolated and identified. Among the isolated bacteria, 80% were Gram-positive and spore-forming. Two of the identified airborne bacteria, Pseudomonas aeruginosa and Bacillus cereus, may cause human disease and are classified in biological agent hazard group 2. The amounts of airborne fungi, molds, and yeasts were 1000 to 2000 colony-forming units (CFUs) per m3. The number of actinomycetes was up to 6-fold, and the number of bacteria was 2- to 20-fold compared to background values. The overall level of airborne bacteria (200 to 3500 CFUs per m3) was low compared to the level of bacteria (105 to 108 CFUs per m3) found when composting municipal waste.  相似文献   
70.
Fluorescent lanthanide chelates with long decay times allow the suppression of the fast decaying autofluorescence in biological specimens. This property makes lanthanide chelates attractive as labels for fluorescence microscopy. As a consequence of the suppression of the background fluorescence the sensitivity can be increased. We modified a standard epifluorescence microscope for time-resolved fluorescence imaging by adding a pulsed light source and a chopper in the narrow aperture plane. A cooled CCD-camera was used for detection and the images were digitally processed. A fluorescent europium chelate was conjugated to antisera and to streptavidin. These conjugates were used for the localization of tumor associated antigen C242 in the malignant mucosa of human colon, for the localization of type II collagen mRNA in developing human cartilaginary growth plates, and for the detection of HPV type specific gene sequences in the squamous epithelium of human cervix. The specific slowly decaying fluorescence of the europium label could be effectively separated from the fast decaying background fluorescence. It was possible to use the europium label at the cell and tissue level and the autofluorescence was effectively suppressed in in situ hybridization and immunohistochemical reactions in both frozen and formaldehyde-fixed, wax-embedded specimens.  相似文献   
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