全文获取类型
收费全文 | 256篇 |
免费 | 19篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 12篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 18篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1967年 | 2篇 |
1960年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 234 毫秒
121.
Gerhard E. Overbeck Eduardo Vlez‐Martin Fabio R. Scarano Thomas M. Lewinsohn Carlos R. Fonseca Sebastian T. Meyer Sandra C. Müller Paula Ceotto Letícia Dadalt Giselda Durigan Gislene Ganade Martin M. Gossner Demetrio L. Guadagnin Katrin Lorenzen Claudia M. Jacobi Wolfgang W. Weisser Valrio D. Pillar 《Diversity & distributions》2015,21(12):1455-1460
122.
Antonio Cascio Mario Barone Vincenzo Micali Chiara Iaria Demetrio Delfino Antonio David Maurizio Monaco Francesco Monaco 《Mycopathologia》2010,169(6):451-455
Introduction
Candida empyema thoracis can be a consequence of operation, gastropleural fistula, and esophageal perforation. Case report and review of the literature. A fatal case of a 45-year-old pregnant woman with Candida krusei empyema thoracis secondary to spontaneous esophagus perforation associated with candida esophagitis is reported. The case is contextualized among similar cases found through a PubMed search. 相似文献123.
Franco Andreone Luca Bartolozzi Giovanni Boano Ferdinando Boero Marco?A. Bologna Mauro Bon Nicola Bressi Massimo Capula Achille Casale Maurizio Casiraghi Giorgio Chiozzi Massimo Delfino Giuliano Doria Antonio Durante Marco Ferrari Spartaco Gippoliti Michele Lanzinger Leonardo Latella Nicola Maio Carla Marangoni Stefano Mazzotti Alessandro Minelli Giuseppe Muscio Paola Nicolosi Telmo Pievani Edoardo Razzetti Giorgio Sabella Marco Valle Vincenzo Vomero Alberto Zilli 《ZooKeys》2014,(456):139-146
The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities. 相似文献
124.
The aim of this study was to assess genetic polymorphism at two loci in the exon 1 of the CSN3 gene in Murgese horse breed by PCR-RFLP analysis. The overall frequencies of alleles A and G at c.-66A?>?G locus were 0.80 and 0.20, respectively, and no GG animals were found in the population. At the c.-36C?>?A locus allelic frequencies were 0.74 and 0.26 for allele C and A, respectively, and no AA animals were detected. Population genetic indexes, namely gene heterozygosity, gene homozygosity, effective allele numbers, fixation index, and polymorphism information index were calculated. Combined genotypic frequencies and possible haplotypes frequencies were also reported. Only three out of nine possible genotypic combinations were found in the studied population. The most frequent genotype was AACC (0.49) while the frequency of AGCA was 0.40. Only five animals were genotyped as AACA (11%). Consequently, the most frequent haplotype in the population was AC (0.744), followed by GA (0.200) and AA (0.056). 相似文献
125.
Massimo Delfino Marcelo R. Sánchez-Villagra 《Seminars in cell & developmental biology》2010,21(4):432-440
Given the large diversity and long stratigraphical range of fossil reptiles, their development is a fundamental aspect of the evolution of ontogeny in vertebrates. Eggs, juveniles, embryos and growth series document different aspects of fossilized ontogenies. About three-fifths of the more than 850 available publications on these topics concern dinosaurs. Non-invasive imaging techniques have facilitated the study of embryos in ovo. Examination of ontogenetic trajectories is used to establish criteria to identify fossil growth series and solve taxonomic issues. Many morphological innovations in reptilian skeletal structures are associated with growth heterochronic changes, whereas sequence heterochronic changes remain largely unstudied but are a potential avenue of research. Relative age assessments via not only palaeohistology but also comparative anatomy have been used to reconstruct life history patterns in fossil archosaurs. Several fossil marine reptiles evolved viviparity convergently. Extinct adult phenotypes can reveal information on development, as in the discovery of polydactyly in diapsids, the examination of vertebral number evolution, and its relation to somitgenesis and Hox-gene boundaries, and signs of tissue regeneration provided by anatomical peculiarities following caudal autotomy. 相似文献
126.
The human c-fes locus encodes a non-receptor protein-tyrosine kinase implicated in myeloid, vascular endothelial, and neuronal cell differentiation. A recent analysis of the tyrosine kinome in colorectal cancer identified c-fes as one of only seven genes with consistent kinase domain mutations. Although four mutations were identified (M704V, R706Q, V743M, S759F), the consequences of these mutations on Fes kinase activity were not explored. To address this issue, Fes mutants with these substitutions were co-expressed with STAT3 in human 293T cells. Surprisingly, the M704V, R706Q, and V743M mutations substantially reduced Fes autophosphorylation and STAT3 Tyr-705 phosphorylation compared with wild-type Fes, whereas S759F had little effect. These mutations had a similar impact on Fes kinase activity in a yeast expression system, suggesting that they inhibit Fes by affecting kinase domain structure. We have also demonstrated for the first time that endogenous Fes is strongly expressed at the base of colonic crypts where it co-localizes with epithelial cells positive for the progenitor cell marker Musashi-1. In contrast to normal colonic epithelium, Fes expression was reduced or absent in colon tumor sections from most individuals. Fes protein levels were also low or absent in a panel of human colorectal cancer cell lines, including HT-29 and HCT 116 cells. Introduction of Fes into these lines with a recombinant retrovirus suppressed their growth in soft agar. Together, our findings strongly implicate the c-Fes protein-tyrosine kinase as a tumor suppressor rather than a dominant oncogene in colorectal cancer. 相似文献
127.
The transmission of Passion fruit woodiness virus (PWV) by Aphis gossypii (Glover) was evaluated. In two independent experiments, A. gossypii transmitted PWV to passion fruit plants at the rates of 75% and 100%, when eight and twelve viruliferous aphids were deposited by plant, respectively. At the end of the tests, nymphs of A. gossypii were observed in some of the passion fruit plants, suggesting that the aphid species was colonizing the plants. This seems to be the first report of Passiflora edulis f. flavicarpa (Deneger) colonization by a species of aphid. 相似文献
128.
Gómez GE Cauerhff A Craig PO Goldbaum FA Delfino JM 《Protein science : a publication of the Protein Society》2006,15(4):744-752
Protein folding, natural conformational changes, or interaction between partners involved in recognition phenomena brings about differences in the solvent-accessible surface area (SASA) of the polypeptide chain. This primary event can be monitored by the differential chemical reactivity of functional groups along the protein sequence. Diazirine (DZN), a photoreactive gas similar in size to water, generates methylene carbene (:CH(2)). The extreme chemical reactivity of this species allows the almost instantaneous and indiscriminate modification of its immediate molecular cage. (3)H-DZN was successfully used in our laboratory for studying protein structure and folding. Here we address for the first time the usefulness of this probe to examine the area of interaction in protein-protein complexes. For this purpose we chose the complex formed between hen egg white lysozyme (HEWL) and the monoclonal antibody IgG(1) D1.3. :CH(2) labeling of free HEWL or complexed with IgG(1) D1.3 yields 2.76 and 2.32 mmol CH(2) per mole protein at 1 mM DZN concentration, respectively. This reduction (15%) becomes consistent with the expected decrement in the SASA of HEWL occurring upon complexation derived from crystallographic data (11%), in agreement with the known unspecific surface labeling reaction of :CH(2). Further comparative analysis at the level of tryptic peptides led to the identification of the sites involved in the interaction. Remarkably, those peptides implicated in the contact area show the highest differential labeling: H(15)GLDNYR(21), G(117)TDVQAWIR(125), andG(22)YSLGNWVCAAK(33). Thus, protein footprinting with DZN emerges as a feasible methodology useful for mapping contact regions of protein domains involved in macromolecular assemblies. 相似文献
129.
130.