全文获取类型
收费全文 | 173篇 |
免费 | 11篇 |
出版年
2023年 | 2篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 11篇 |
2012年 | 19篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有184条查询结果,搜索用时 218 毫秒
41.
Emilia R. Franklin Piers D. Mitchell John Robb 《American journal of physical anthropology》2023,182(3):452-466
Objectives
This study explores the paleoepidemiology of the Black Death (1348–52 AD) mass graves from Hereford, England, via osteological analysis. Hereford plague mortality is evaluated in the local context of the medieval city and examined alongside other Black Death burials.Methods
The Hereford Cathedral site includes mass graves relating to the Black Death and a 12th-16th century parish cemetery. In total, 177 adult skeletons were analyzed macroscopically: 73 from the mass graves and 104 from the parish cemetery. Skeletal age-at-death was assessed using transition analysis, and sex and stress markers were analyzed.Results
The age-at-death distributions for the mass graves and parish cemetery were significantly different (p = 0.0496). Within the mass graves, young adults (15–24 years) were substantially over-represented, and mortality peaked at 25–34 years. From 35 years of age onwards, there was little variation in the mortality profiles for the mass graves and parish cemetery. Males and females had similar representation across burial types. Linear enamel hypoplasia was more prevalent within the mass graves (p = 0.0340) whereas cribra orbitalia and tibial periostitis were underrepresented.Conclusions
Mortality within the Hereford mass graves peaked at a slightly older age than is seen within plague burials from London, but the overall profiles are similar. This demonstrates that young adults were disproportionately at risk of dying from plague compared with other age groups. Our findings regarding stress markers may indicate that enamel hypoplasia is more strongly associated with vulnerability to plague than cribra orbitalia or tibial periostitis. 相似文献42.
Calreticulin: not just another calcium-binding protein 总被引:15,自引:0,他引:15
In this paper we review some of the rapidly expanding information about calreticulin, a Ca2+-binding/storage protein of the endoplasmic reticulum. The emphasis is placed on the structure and function of calreticulin. We believe that calreticulin is a multifunctional Ca2+-binding protein and that distinct functional properties of the protein may be localized to each of the three structural domains of calreticulin. Most evidence indicates that calreticulin is a resident endoplasmic reticulum protein. However, it can also be found outside of the endoplasmic reticulum compartment, i.e. in the nuclear envelope, in the nucleus, in the cytotoxic granules in T-lymphocytes and in acrosomal vesicles of sperm cells. The evidence reviewed here clearly suggests that calreticulin has other functions in addition to its role as a Ca2+ storage protein in the endoplasmic reticulum.Abbreviations SR
sarcoplasmic reticulum
- ER
endoplasmic reticulum 相似文献
43.
Psoriatic arthritis is a greatly underreported seronegative erosive arthropathy, due to the ambiguous lesions it leaves on bone in all but the most severe cases. For a confident diagnosis of psoriatic arthritis to be made, sacroiliac and intervertebral joint fusion must be present together with erosive lesions of the peripheral skeleton including most especially the terminal interphalangeal joints. In modern times it is only a small percentage of cases who experience such debilitating disease, which may explain who so few cases of psoriatic arthritis can confidently be identified from past populations. This report describes this pathological condition as observed in the comingled skeletal remains of nine males and one female from the tomb of Paulus in the Byzantine Monastery of Martyrius, in the Judean Desert. Visual study was complemented using radiographic techniques along with scanning electron microscopy. Two adult males show characteristic lesions of psoriatic arthritis, demonstrating the form known as arthritis mutilans. A third individual shows less widespread erosive lesions which may signify a pauciarticular example of psoriatic arthritis, as is true of most cases in modern times, or the remains may represent Reiter's disease. During the Byzantine period the earlier practise of expelling those with disfiguring diseases (biblical leprosy) evolved into a philanthropic, caring philosophy where the sick were housed and fed out of charity, often within monasteries. The presence of these cases of psoriatic arthritis within such a Judean Desert monastery confirms earlier suggestions that psoriasis was one of the diseases included by those in the ancient eastern Mediterranean under the umbrella term of biblical leprosy. © 1996 Wiley-Liss, Inc. 相似文献
44.
Cromheecke M Piers BA Beekhuis H ter Veen H Sluiter WJ Grond AK Hoekstra HJ 《Radiation research》2000,154(5):537-546
To establish the tolerance of liver tissue to single high-dose intraoperative irradiation, the histopathological changes in the canine liver after single high-dose intraoperative irradiation were investigated by means of radionuclide imaging and light microscopy. Intraoperative irradiation at doses of 0, 10, 20, 25 or 30 Gy was applied to a part of the liver of 25 beagles. Radionuclide imaging using (99m)Tc-sulfur colloid was performed at several times during follow-up. Elective humane killing was done 3 months and 1, 2, 3 and 5 years after irradiation. Light microscopy was used to identify histopathological alterations. There was no morbidity or mortality during a maximal follow-up of 5 years. In 40% of the animals, a region of diminished uptake was observed at the irradiation site. The regions of diminished uptake of the radiopharmaceutical agent became smaller with time. Light microscopic examination revealed severe parenchymal fibrosis, liver cell atrophy, and bile duct proliferation at the irradiated area 1 to 2 years after irradiation. At 3 and 5 years, vascular changes with endothelial proliferation and focal arteriolar hyalinosis were observed. This study demonstrates that intraoperative irradiation of a part of the liver in the canine model can be applied safely. Light microscopy confirmed that histological damage was not always accompanied by diminished uptake of the radiopharmaceutical agent at the irradiation site. 相似文献
45.
The basidiomycete Coprinopsis cinerea (Coprinus cinereus) expresses two fruiting body-specific isolectins (CGL1 and CGL2) that belong to the family of galectins. Understanding the role of these beta-galactoside binding lectins is still in the beginning. Even though the prerequisites for substrate binding are well understood, it is not known how discrimination between potential substrates is achieved and what kind of influence this has on the function in a distinct cellular context. Precise knowledge of the expression of galectins and their ligands will aid in elucidating their function. In Coprinopsis, the developmentally regulated ligands for galectins co-localise with galectin expression in the veil surrounding the developing primordium and the outer cells of the young stipe. In addition, galectin ligands are observed in the hymenium. The subcellular localisation of the galectin ligands suggests these to be present in cellular compartments distinct from galectin transport. The sensitivity of the in situ interactions with exogenous galectin towards detergents and organic solvents infers that these ligands are lipid-borne. Accordingly, lipid fractions from primordia are shown to contain galectin-binding compounds. Based on these results and the determined binding specificity towards substituted beta-galactosides we hypothesise that beta-galactoside-containing lipids (basidiolipids) found in mushrooms are physiological ligands for the galectins in C. cinerea. 相似文献
46.
47.
Matthew J. Larcombe Joaquim S. Silva René E. Vaillancourt Brad M. Potts 《Biological invasions》2013,15(12):2763-2781
Eucalyptus globulus is one of the most widely planted temperate hardwood species in the world, and in Australia there are 538,000 hectares growing in plantations. Although it has been reported as invasive, quantification of E. globulus invasion is rare. We conducted surveys at two geographic scales to assess the level of, and factors influencing, wildling establishment from industrial E. globulus plantations in Australian. We surveyed 290 km of plantation boundary, both within (22 %) and outside (78 %) the species native range. In areas of relatively high establishment, a density triggered paired plot approach (plots with and without wildlings) was used to assess fine-scale factors influencing establishment. We recorded 4,939 wildlings (17/km), 98 % of which occurred within 10 m of the plantation edge (maximum 175 m). Establishment varied between regions, ranging from 1.2 to 39.6 wildlings/km. Generalized linear models showed that the probability of a wildling being present increased with plantation age, that wildling abundance was higher along burnt transects, as well as sites that received regular, relatively high rainfall and had lower mean annual temperatures. The only fine-scale/local factor influencing wildling presence was the reproductive output of the plantation. The current level of E. globulus establishment in Australia is low in comparison to other invasive forestry trees. However, given the relatively young age of the Australian estate, local and regional variation in establishment, and potential future changes in plantation management, monitoring is warranted. Implications for assessing the general invasiveness of Eucalyptus and possibilities for E. globulus wildling control are discussed. 相似文献
48.
49.
Piletska EV Stavroulakis G Larcombe LD Whitcombe MJ Sharma A Primrose S Robinson GK Piletsky SA 《Biomacromolecules》2011,12(4):1067-1071
Here we present the first molecular imprinted polymer (MIP) that is able to attenuate the biofilm formation of the opportunistic human pathogen Pseudomonas aeruginosa through specific sequestration of its signal molecule N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C(12)-AHL). The MIP was rationally designed using computational modeling, and its capacity and specificity and that of a corresponding blank polymer toward signal molecule of P. aeruginosa (3-oxo-C(12)-AHL) and its analogue were tested. The biofilm formation in the presence of polymers and without polymers was studied using scanning confocal laser microscopy. Staining with crystal violet dye was used for the quantification of the biofilm formation. A significant reduction of the biofilm growth was observed in the presence of MIP (>80%), which was superior to that of the resin prepared without template, which showed a reduction of 40% in comparison with biofilm, which was grown without polymer addition. It was shown that 3-oxo-C(12)-AHL-specific MIP prevented the development of quorum-sensing-controlled phenotypes (in this case, biofilm formation) from being up-regulated. The developed MIP could be considered as a new tool for the elimination of life-threatening infections in a multitude of practical applications; it could, for example, be grafted on the surface of medical devices such as catheters and lenses, be a component of paints, or be used as a wound adsorbent. 相似文献
50.
Signal transduction from G-protein coupled receptors to MAPK cascades through heterotrimeric G-proteins has been described for many eukaryotic systems. One of the best-characterised examples is the yeast pheromone response pathway, which is negatively regulated by AKR1. AKR1-like proteins are present in all eukaryotes and contain a DHHC domain and six ankyrin repeats. Whilst the DHHC domain dependant S-acyl transferase (palmitoyl transferase) function of AKR1 is well documented it is not known whether the ankyrin repeats are also required for this activity. Here we show that the ankyrin repeats of AKR1 are required for full suppression of the yeast pheromone response pathway, by sequestration of the Gβγ dimer, and act independently of AKR1 S-acylation function. Importantly, the functions provided by the AKR1 ankyrin repeats and DHHC domain are not required on the same molecule to fully restore WT phenotypes and function. We also show that AKR1 molecules are S-acylated at locations other than the DHHC cysteine, increasing the abundance of AKR1 in the cell. Our results have important consequences for studies of AKR1 function, including recent attempts to characterise S-acylation enzymology and kinetics. Proteins similar to AKR1 are found in all eukaryotes and our results have broad implications for future work on these proteins and the control of switching between Gβγ regulated pathways. 相似文献