全文获取类型
收费全文 | 303篇 |
免费 | 15篇 |
专业分类
318篇 |
出版年
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 14篇 |
2014年 | 12篇 |
2013年 | 13篇 |
2012年 | 20篇 |
2011年 | 18篇 |
2010年 | 11篇 |
2009年 | 13篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 18篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 14篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有318条查询结果,搜索用时 15 毫秒
71.
Marianna Rossetti Rosa Merlo Neda Bagheri Danila Moscone Anna Valenti Aakash Saha Pablo
R Arantes Rudy Ippodrino Francesco Ricci Ida Treglia Elisabetta Delibato John van
der
Oost Giulia Palermo Giuseppe Perugino Alessandro Porchetta 《Nucleic acids research》2022,50(14):8377
The RNA programmed non-specific (trans) nuclease activity of CRISPR-Cas Type V and VI systems has opened a new era in the field of nucleic acid-based detection. Here, we report on the enhancement of trans-cleavage activity of Cas12a enzymes using hairpin DNA sequences as FRET-based reporters. We discover faster rate of trans-cleavage activity of Cas12a due to its improved affinity (Km) for hairpin DNA structures, and provide mechanistic insights of our findings through Molecular Dynamics simulations. Using hairpin DNA probes we significantly enhance FRET-based signal transduction compared to the widely used linear single stranded DNA reporters. Our signal transduction enables faster detection of clinically relevant double stranded DNA targets with improved sensitivity and specificity either in the presence or in the absence of an upstream pre-amplification step. 相似文献
72.
Sabio y García JV Farber M Carrica M Cravero S Macedo GC Bigi F Oliveira SC Rossetti O Campos E 《Microbes and infection / Institut Pasteur》2008,10(6):635-641
Brucella abortus strain 19 (live vaccine) induces a strong humoral and cellular immune response and therefore, it is an attractive vector for the delivery of heterologous antigens. The objective of the present study was to express the rhoptry-associated protein (RAP1) of Babesia bovis in B. abortus S19, as a model for heterologous expression of immunostimulatory antigens from veterinary pathogens. A plasmid for the expression of recombinant proteins fused to the aminoterminal of the outer membrane lipoprotein OMP19 was created, pursuing the objective of increasing the immunogenicity of the recombinant antigen being expressed by its association to a lipid moiety. Recombinant strains of B. abortus S19 expressing RAP1 as a fusion protein either with the first amino acids of beta-galactosidase (S19pBB-RAP1) or B. abortus OMP19 (S19pBB19-RAP1) were generated. Plasmid stability and the immunogenicity of the heterologous proteins were analyzed. Mice immunized with S19pBB-RAP1 or S19pBB19-RAP1 developed specific humoral immune response to RAP1, IgG2a being the predominant antibody isotype. Furthermore, a specific cellular immune response to recombinant RAP1 was elicited in vitro by lymphocytes from mice immunized with both strains. Therefore, we concluded that B. abortus S19 expressing RAP1 is immunostimulatory and may provide the basis for combined heterologous vaccines for babesiosis and brucellosis. 相似文献
73.
Motomu Tanaka Murat Tutus Stefan Kaufmann Fernanda F. Rossetti Emanuel Schneck Ingrid M. Weiss 《Journal of structural biology》2009,168(1):137
To bridge soft biological materials and hard inorganic materials is an interdisciplinary scientific challenge. Despite of experimental difficulties, the deposition of native biological membranes on supports is a straightforward strategy. This review provides an overview of advances in the fabrication and characterization of native biological membranes on planar polymer supports and micro-particles. 相似文献
74.
Reference proteome of highly purified human Th1 cells reveals strong effects on metabolism and protein ubiquitination upon differentiation 下载免费PDF全文
Massimiliano Pagani Maxie Rockstroh Maj Schuster Grazisa Rossetti Monica Moro Mariacristina Crosti Janina M. Tomm 《Proteomics》2015,15(21):3644-3647
The differentiation of human CD4+ T cells into T helper cell subtypes and regulatory T cells is crucial to the immune response. Among subtypes, Th1 cells are dominant, representing approximately 50% of all lymphocytes. Thus far, most global proteomic studies have used only partially purified T helper cell subpopulations and/or have employed artificial protocols for inducing specific T helper cell subtypes and/or used gel‐based approaches. These studies have shed light on molecular details of certain aspects of the proteome; nevertheless a global analysis of high purity primary naïve and Th1 cells by LC‐MS/MS is required to provide a reference dataset for proteome‐based T cell subtype characterization. The utilization of highly purified Th1 cells for a global proteome assessment and the bioinformatic comparison to naïve cells reveals changes in cell metabolism and the ubiquitination pathway upon T cell differentiation. All MS data have been deposited in the ProteomeXchange with identifier PXD001066 ( http://proteomecentral.proteomexchange.org/dataset/PXD001066 ). 相似文献
75.
76.
77.
Federico Aulenta Andrea Canosa Priscilla Reale Simona Rossetti Stefania Panero Mauro Majone 《Biotechnology and bioengineering》2009,103(1):85-91
In situ bioremediation of industrial chlorinated solvents, such as trichloroethene (TCE), is typically accomplished by providing an organic electron donor to naturally occurring dechlorinating populations. In the present study, we show that TCE dechlorinating bacteria can access the electrons required for TCE dechlorination directly from a negatively polarized (?450 mV vs. SHE) carbon paper electrode. In replicated batch experiments, a mixed dechlorinating culture, also containing Dehalococcoides spp., dechlorinated TCE to cis‐dichloroethene (cis‐DCE) and lower amounts of vinyl chloride (VC) and ethene using the polarized electrode as the sole electron donor. Conversely, neither VC nor ethene formation occurred when a pure culture of the electro‐active microorganism Geobacter lovleyi was used, under identical experimental conditions. Cyclic voltammetry tests, carried out on the filter‐sterilized supernatant of the mixed culture revealed the presence of a self‐produced redox mediator, exhibiting a midpoint potential of around ?400 mV (vs. SHE). This yet unidentified redox‐active molecule appeared to be involved in the extracellular electron transfer from the electrode to the dechlorinating bacteria. The ability of dechlorinating bacteria to use electrodes as electron donors opens new perspectives for the development of clean, versatile, and efficient bioremediation systems based on a controlled subsurface delivery of electrons in support of biodegradative metabolisms and provides further evidence on the possibility of using conductive materials to manipulate and control a range of microbial bioprocesses. Biotechnol. Bioeng. 2009;103: 85–91. © 2008 Wiley Periodicals, Inc. 相似文献
78.
Inzitari R Cabras T Rossetti DV Fanali C Vitali A Pellegrini M Paludetti G Manni A Giardina B Messana I Castagnola M 《Proteomics》2006,6(23):6370-6379
Statherin is a multifunctional polypeptide specific of human saliva involved in oral calcium homeostasis, phosphate buffering and formation of protein networks. Salivary P-B peptide is usually included into the basic proline-rich protein family but it shows some similarities with statherin and its specific biological role is still undefined. In this study, various fragments and derivatives of statherin and P-B peptide were consistently detected by RP-HPLC ESI-IT MS in 23 samples of human saliva. They were: statherin mono- and non-phosphorylated, statherin Des-Phe(43) (statherin SV1), statherin Des-Thr(42),Phe(43), statherin Des-Asp(1), statherin Des(6-15) (statherin SV2), statherin Des(1-9), statherin Des(1-10), statherin Des(1-13) and P-B Des(1-5). Statherin SV3 (statherin Des(6-15), Phe(43)) was detected only in one sample. Identity of the fragments was confirmed either by MS/MS experiments or by enzymatic digestion or by Edman sequencing. Detection of the fragments suggests that statherin and P-B peptide are submitted to post-translational proteolytic cleavages that are common to other classes of salivary proteins. 相似文献
79.
Cristina Bondavalli Antonio Bodini Giampaolo Rossetti Stefano Allesina 《Ecosystems》2006,9(5):768-787
Detecting the early signs of stress is imperative for the conservation of natural ecosystems. They may, however, go unrecognized
because ecosystems, when disturbed, may act as sinks that absorb the external impact without showing any evident changes.
This seems to be the case for Lake Santo, a small water body located in a mountainous area of northern Italy. Tourism activity
in this area began to develop in the early 1970s and grew continuously over the following 20 years. This activity caused a
continually increasing nutrient load into the waters, but surprisingly the lake has remained oligo-mesotrophic, as it was
before human pressure became a stressor to the lake. To anticipate possible severe damage to the ecosystem, we searched for
early signs of stress by carrying out a retrospective analysis based on a whole-ecosystem approach using trophic flow networks.
Ecosystem properties of the lake as calculated from network analysis for the disturbed (year 1991) and unimpacted (year 1973)
configurations were compared, with the support of sensitivity analysis and statistical tests. We found evidence that in the
period 1970–90 nutrient enrichment did change the course of normal development as the observed increase in system throughput
was accompanied by a drop in the level of mutual organization of flows, which instead would be expected to increase during
the natural progression of the ecosystem. The scenario that emerged from the comparison of system-level indices, cycling activity,
trophic structure, and trophic efficiency indicates that the ecosystem has been subjected to stress. In particular, the type
of disturbance corresponds to a quantitative definition of eutrophication. 相似文献
80.
Castagnola M Inzitari R Rossetti DV Olmi C Cabras T Piras V Nicolussi P Sanna MT Pellegrini M Giardina B Messana I 《The Journal of biological chemistry》2004,279(40):41436-41443
The systematic search by tandem mass spectrometry of human saliva from four different subjects, of 136 possible fragments originated from histatin 3, allowed the detection of 24 different peptides. They include, with the exception of histatin 4, all the known histatin 3 fragments, namely histatins 5-12 and the peptides corresponding to 15-24, 26-32, 29-32 residues, and 13 new fragments corresponding to 1-11, 1-12, 1-13, 5-13, 6-11, 6-13, 7-11, 7-12, 7-13, 14-24, 14-25, 15-25, and 28-32 residues of histatin 3. On the contrary, none of 119 possible fragments of histatin 1, including histatin 2, was detected. The results suggest that the genesis of histatin 3-related peptides, being under the principal action of trypsin-like activities, is probably not a random process but rather follows a sequential fragmentation pathway. Lack of detection of C-terminal fragments, with the exception of 26-32, 28-32, and 29-32 fragments, suggested that arginine 25 should be the first cleavage site, generating histatin 6 and 26-32 fragments. The genesis of 28-32 and 29-32 fragments and histatin 5 should implicate a subsequent exo-protease action. Similarly, lack of detection of fragments having Lys-5 and Arg-6 at the N terminus and Arg-25 at the C terminus strongly suggested that sequences KRKF (11-14 residues) and AKR (4-6 residues) should be the second and the third cleavage sites, respectively. Lys-17 and Arg-22 are not cleaved at all. 相似文献