全文获取类型
收费全文 | 252篇 |
免费 | 17篇 |
出版年
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 19篇 |
2012年 | 17篇 |
2011年 | 15篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 14篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 9篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 9篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 15 毫秒
31.
E. Chiarpotto F. Biasi M. Aragno A. Scavazza O. Danni E. Albano G. Poli 《Cell biochemistry and function》1993,11(1):71-75
The combination of carbon tetrachloride (CCl4) and 1,2-dibromoethane (DBE) in isolated rat hepatocytes led to a significant potentiation of both lipid peroxidation and of plasma membrane damage observed after a single treatment with CCl4. Such a synergistic effect appeared to be related to the CCl4-induced shift of DBE metabolism from the cytosolic conjugation with glutathione towards the microsomal transformation into toxic intermediates. In fact, CCl4 significantly inactivated hepatocyte total GSH-transferase, i.e. the DBE detoxification pathway. Furthermore, while the microsomal metabolism of CCl4 was not affected by the simultaneous presence of DBE, the amount of DBE reactive metabolities covalently bound to hepatocyte protein was significantly enhanced in the presence of CCl4. 相似文献
32.
Marcin Górecki Maria Annunziata M. Capozzi Gianluigi Albano Cosimo Cardellicchio Lorenzo Di Bari Gennaro Pescitelli 《Chirality》2018,30(1):29-42
Three β‐keto sulfoxides ( 1–3 ) were synthesized in enantiopure form and investigated by means of circular dichroism (CD) spectroscopy, both in electronic and vibrational range (ECD, VCD), in combination with quantum chemical calculations. For compound 2 , the X‐ray structure was available; thus, the ECD in the solid state was also considered to reveal the differences between the molecular species in both states. Despite the simplicity of all β‐keto sulfoxides under investigation (29 atoms), reproducing even the major spectral VCD features failed for two compounds, making the use of VCD not ideal to assign their absolute configuration in a reliable way. We demonstrated, however, that the use of ECD spectroscopy, both in solution and solid state, can easily, unambiguously, and without any complication simulate all bands by applying the standard protocol for calculations. This study may stimulate the debate on the need of the use of two chiroptical methods simultaneously in the determination of absolute configurations. 相似文献
33.
An updated checklist of the vascular flora native to Italy 总被引:1,自引:0,他引:1
F. Bartolucci L. Peruzzi G. Galasso A. Albano A. Alessandrini N. M. G. Ardenghi 《Plant biosystems》2018,152(2):179-303
An updated inventory of the native vascular flora of Italy, providing details on the occurrence at regional level, is presented. The checklist includes 8195 taxa (6417 species and 1778 subspecies), distributed in 1092 genera and 152 families; 23 taxa are lycophytes, 108 ferns and fern allies, 30 gymnosperms and 8034 angiosperms. The taxa currently occurring in Italy are 7483, while 568 taxa have not been confirmed in recent times, 99 are doubtfully occurring in the country and 19 are data deficient. Out of the 568 not confirmed taxa, 26 are considered extinct or possibly extinct. 相似文献
34.
Brodfuehrer PD McCormick K Tapyrik L Albano AM Graybeal C 《Invertebrate neuroscience : IN》2008,8(1):31-39
Higher-order projection interneurons that function in more than one behavior have been identified in a number of preparations.
In this study, we document that stimulation of cell Tr1, a previously identified trigger interneuron for swimming in the medicinal
leech, can also elicit the motor program for crawling in isolated nerve cords. We also show that motor choice is independent
of the firing frequency of Tr1 and amount of spiking activity recorded extracellularly at three locations along the ventral
nerve cord prior to Tr1 stimulation. On the other hand, during Tr1 stimulation there is a significant difference in the amount
of activity elicited in the ventral nerve cord that correlates with the motor program activated. On average, Tr1 stimulation
trials that lead to crawling elicit greater amounts of activity than in trials that lead to swimming. 相似文献
35.
Relationships between bacterial diversity and environmental variables in a tropical marine environment, Rio de Janeiro 总被引:6,自引:0,他引:6
Vieira RP Gonzalez AM Cardoso AM Oliveira DN Albano RM Clementino MM Martins OB Paranhos R 《Environmental microbiology》2008,10(1):189-199
This study is the first to apply a comparative analysis of environmental chemistry, microbiological parameters and bacterioplankton 16S rRNA clone libraries from different areas of a 50 km transect along a trophic gradient in the tropical Guanabara Bay ecosystem. Higher bacterial diversity was found in the coastal area, whereas lower richness was observed in the more polluted inner bay water. The significance of differences between clone libraries was examined with libshuff statistics. Paired reciprocal comparisons indicated that each of the libraries differs significantly from the others, and this is in agreement with direct interpretation of the phylogenetic tree. Furthermore, correspondence analyses showed that some taxa are related to specific abiotic, trophic and microbiological parameters in Guanabara Bay estuarine system. 相似文献
36.
Tiago Antao Ana Lopes Ricardo J Lopes Albano Beja-Pereira Gordon Luikart 《BMC bioinformatics》2008,9(1):323
Background
Testing for selection is becoming one of the most important steps in the analysis of multilocus population genetics data sets. Existing applications are difficult to use, leaving many non-trivial, error-prone tasks to the user. 相似文献37.
Platteau P.; Desmet B.; Odoma G.; Albano C.; Devroey P.; Sali E. Tamale 《ESHRE Monographs》2008,2008(1):90-92
4Correspondence address. Zonlaan 49, 1700 Dilbeek, Belgium. E-mail: peterplatteau{at}telenet.be We all know that starting and running an ART clinic is not soeasy as some people might perceive from outside. Doing the samething in the middle of Africa is even more challenging as someevidences in the Western world are not so obvious in this partof the world. We started our clinic in Kampala in 2004. Theclinic was a converted apartment from a four flat building.In the beginning, we had difficulties with importing drugs,culture media and consumables; we had the feeling everybodywas against us. We overcame multiple power failures, night intrudersand a 20% masturbation failure, but once the first IVF/ICSIbabies were born, people started to believe in the project.At present, 250 IVF/ICSI cycles a year are done in batches,we have a successful embryo freezing programme, offer IUI/ICSIfor sero discordant HIV couples and have the first babies afterIVF, ICSI, testicular biopsy, embryo freezing, oocyte donationand surrogacy in Central Africa. The results are comparableto the ones in the Western world. 相似文献
38.
Dé E Saint N Glinel K Meli AC Lévy D Jacob-Dubuisson F 《Molecular membrane biology》2008,25(3):192-202
Autotransporters are a superfamily of proteins secreted by Gram-negative bacteria including many virulence factors. They are modular proteins composed of an N-terminal signal peptide, a surface-exposed 'passenger' domain carrying the activity of the protein, and a C-terminal 'translocator' domain composed of an alpha-helical linker region and a transmembrane beta-barrel. The translocator domain plays an essential role for the secretion of the passenger domain across the outer membrane; however, the mechanism of autotransport remains poorly understood. The whooping cough agent Bordetella pertussis produces an autotransporter serine-protease, SphB1, which is involved in the maturation of an adhesin at the bacterial surface. SphB1 also mediates the proteolytic maturation of its own precursor. We used SphB1 as a model autotransporter and performed the first comparisons of the biochemical and biophysical properties of an isolated translocator domain with those of the same domain preceded by the C-terminal moiety of its natural passenger. By using cross-linking and dynamic light scattering, we provide evidence that the passenger domain promotes the auto-association of SphB1, although these interactions appear rather labile. Electrophysiological studies revealed that the passenger domain of the autotransporter appears to maintain the translocator channel in a low-conductance conformation, most likely by stabilizing the alpha-helix inside the pore. That the passenger may significantly influence AT physicochemical properties is likely to be relevant for the in vivo maturation and stability of AT proteins. 相似文献
39.
There is a major need to understand the historical condition and chemical/biological functions of the ecosystems following a conversion of wetlands to agricultural functions. To better understand the dynamics of soil total organic carbon (TOC) and phosphorus (P) during beef cattle pastures to wetland reconversion, soil core samples were collected from the beef cattle pasture and from the natural wetland at Plant City, FL, during five summer seasons (2002–2007). The levels of TOC and soil P were significantly affected by changing land use and hydrology. Draining natural wetlands to grazed pastures resulted in very pronounced reduction of TOC from 180.1 to 5.4 g g?1. Cumulative concentrations of total phosphorus (TP) in soils (1134 mg kg?1) under drained condition are two to three times lower than those in soils (2752 mg kg?1) under flooded condition over the periods of land use reconversion. There was a declining trend (r = 0.82**; p ≤ 0.01) in total soil P from natural wetland (763 mg kg?1) to altered pastures (340 mg kg?1), largely as organic-bound P (natural wetland, 48%; grazed pastures, 44%; altered pastures, 29%). These results are important in establishing baseline information on soil properties in pasture and wetland prior to restoring and reconverting pasture back to wetland conditions. The results further suggest that changes in soil properties due to changing land use and hydrologic conditions (drying and re-wetting) could be long lasting. 相似文献
40.
Albano C. Meli Maria Kondratova Virginie Molle Laurent Coquet Andrey V. Kajava Nathalie Saint 《The Journal of membrane biology》2009,230(3):143-154
Attachment to host tissues is a critical step in the pathogenesis of most bacterial infections. Enterotoxigenic Escherichia coli (ETEC) remains one of the principal causes of infectious diarrhea in humans. The recent identification of additional ETEC
surface molecules suggests that new targets may be exploited in vaccine development. The EtpA protein identified in ETEC H10407
is a large glycosylated adhesin secreted via the two-partner secretion system. EtpA requires its putative partner EtpB for
translocation across the outer membrane (OM). We investigated the biochemical and electrophysiological properties of purified
EtpB. We showed that EtpB is 65-kDa heat-modifiable protein localized to the OM. Electrophysiological experiments indicated
that EtpB is able to form pores in planar lipid bilayer membranes with an asymmetric current, suggesting its functional asymmetry.
The pore of EtpB frequently assumes an opened conformation and fluctuates between three well-defined conductance states. In
silico analysis of the EtpB amino acid sequence and molecular modeling suggest that EtpB is similar to the well-known TpsB
protein FhaC from Bordetella pertussis and has a C-terminal transmembrane β-barrel domain that is occluded by an N-terminal α-helix, an extracellular loop, and
two periplasmic polypeptide-transport-associated (POTRA) domains. Together, these data confirm that EtpB is a pore-forming
protein mainly folded into a β-barrel conformation and indicate that EtpB presents typical features of the OM TpsB proteins. 相似文献