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61.
Structure and organization of the bovine beta-globin genes 总被引:1,自引:0,他引:1
Genomic clones spanning the entire cow beta-globin gene locus have been
isolated and characterized. These clones demonstrate that the linkage of
embryonic-like (epsilon) genes and pseudogenes (psi) to the previously
described fetal (gamma) and adult (beta) genes is as follows: 5'-epsilon
3-epsilon 4-psi 3-beta-epsilon 1-epsilon 2-psi 1- psi 2-gamma-3'. Present
data indicate that, like that of the goat, the fetal and adult genes arose
via block duplication of an ancestral four- gene set:
epsilon-epsilon-psi-beta. This duplication event preceded the divergence of
cows and goats, which occurred greater than or equal to 18-20 Myr ago.
However, cows do not have the additional four-gene block containing a
preadult/stress globin gene (beta C). Furthermore, the cow fetal cluster
contains an extra beta-like pseudogene, which apparently arose by a
small-scale duplication. The fixation of this duplication may indicate a
possible evolutionary role for pseudogenes.
相似文献
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64.
Ndom JC Mbafor JT Azebaze AG Vardamides JC Kakam Z Kamdem AF Deville A Ngando TM Fomum ZT 《Phytochemistry》2006,67(8):838-842
A cacalolide derivative named 4alpha-[2'-hydroxymethylacryloxy]-1beta-hydroxy-14-(5-->6) abeo eremophilan-12,8-olide and a shikimic acid derivative named (3'E)-(1alpha)-3-hydroxymethyl-4beta,5alpha-dimethoxycyclohex-2-enyloctadec-3'-enoate along with three known compounds, octacosan-1-ol, 3beta-hydroxyolean-12-en-28-oic acid and 3beta-acetoxyolean-12-en-28-oic acid were isolated from Senecio burtonii. Their structures and relative configurations were established on the basis of spectroscopic analysis. 相似文献
65.
JC de Mauroy HR Weiss AG Aulisa L Aulisa JI Brox J Durmala C Fusco TB Grivas J Hermus T Kotwicki G Le Blay A Lebel L Marcotte S Negrini L Neuhaus T Neuhaus P Pizzetti L Revzina B Torres PJM Van Loon E Vasiliadis M Villagrasa M Werkman M Wernicka MS Wong F Zaina 《Scoliosis》2010,5(1):1-15
Abstract
Thoracic hyperkyphosis is a frequent problem and can impact greatly on patient's quality of life during adolescence. This condition can be idiopathic or secondary to Scheuermann disease, a disease disturbing vertebral growth. To date, there is no sound scientific data available on the management of this condition. Some studies discuss the effects of bracing, however no guidelines, protocols or indication's of treatment for this condition were found. The aim of this paper was to develop and verify the consensus on managing thoracic hyperkyphosis patients treated with braces and/or physiotherapy.Methods
The Delphi process was utilised in four steps gradually modified according to the results of a set of recommendations: we involved the SOSORT Board twice, then all SOSORT members twice, with a Pre-Meeting Questionnaire (PMQ), and during a Consensus Session at the SOSORT Lyon Meeting with a Meeting Questionnaire (MQ).Results
There was an unanimous agreement on the general efficacy of bracing and physiotherapy for this condition. Most experts suggested the use of 4-5 point bracing systems, however there was some controversy with regards to physiotherapeutic aims and modalities.Conclusion
The SOSORT panel of experts suggest the use of rigid braces and physiotherapy to correct thoracic hyperkyphosis during adolescence. The evaluation of specific braces and physiotherapy techniques has been recommended. 相似文献66.
Tan JC Miller BA Tan A Patel JJ Cheeseman IH Anderson TJ Manske M Maslen G Kwiatkowski DP Ferdig MT 《Genome biology》2011,12(4):R35
We present an optimized probe design for copy number variation (CNV) and SNP genotyping in the Plasmodium falciparum genome. We demonstrate that variable length and isothermal probes are superior to static length probes. We show that sample
preparation and hybridization conditions mitigate the effects of host DNA contamination in field samples. The microarray and
workflow presented can be used to identify CNVs and SNPs with 95% accuracy in a single hybridization, in field samples containing
up to 92% human DNA contamination. 相似文献
67.
The Glutaraldehyde test (GT), a rapid and inexpensive test, has been utilized empirically for many years in bovine practice
for diagnosing inflammatory diseases. GT is used primarily to demonstrate increased serum concentrations of fibrinogen and
globulin. Glutaraldehyde binds with free amino groups in fibrinogen and immunoglobulin to create a clot in a first degree
chemical reaction. The clotting time of the GT estimates the content of proteins produced in response to inflammation. The
applicability of GT for diagnosing inflammation in the horse has never been investigated. The objective of this study was
to determine the ability of GT to distinguish between acute and chronic inflammatory disease in horses. Thirty-seven horses
with suspected inflammatory diseases were evaluated using the GT, history, complete clinical examination and routine blood
analysis. GT-times, laboratory results and clinical outcome were compared statistically. Horses that were determined to be
acutely affected (based on history, clinical examination and routine blood analysis) tended to have a negative GT (75%). Results
of the GT did not correlate with blood fibrinogen concentration. Positive GT also predicted a fatal outcome in 69% of the
clinical cases. The results of this trial indicate that GT can be a useful screening test to distinguish between acute and
chronic inflammatory disease in horses. 相似文献
68.
69.
REL Paul T Lafond CDM Müller-Graf S Nithiuthai PT Brey JC Koella 《BMC evolutionary biology》2004,4(1):30
Background
Evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. Establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. In this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by mortality. The majority of natural infections, however, result in sub-lethal virulent effects (e.g. anaemia) and are often composed of many strains. Both sub-lethal effects and pathogen population structure have been theoretically shown to have important consequences for virulence evolution. Thus, we additionally examine the relationship between anaemia and transmission in single and mixed clone infections. 相似文献70.
S S Metkar M Marchioretto V Antonini L Lunelli B Wang R JC Gilbert G Anderluh R Roth M Pooga J Pardo J E Heuser M D Serra C J Froelich 《Cell death and differentiation》2015,22(1):74-85
Perforin-mediated cytotoxicity is an essential host defense, in which defects contribute to tumor development and pathogenic disorders including autoimmunity and autoinflammation. How perforin (PFN) facilitates intracellular delivery of pro-apoptotic and inflammatory granzymes across the bilayer of targets remains unresolved. Here we show that cellular susceptibility to granzyme B (GzmB) correlates with rapid PFN-induced phosphatidylserine externalization, suggesting that pores are formed at a protein-lipid interface by incomplete membrane oligomers (or arcs). Supporting a role for these oligomers in protease delivery, an anti-PFN antibody (pf-80) suppresses necrosis but increases phosphatidylserine flip-flop and GzmB-induced apoptosis. As shown by atomic force microscopy on planar bilayers and deep-etch electron microscopy on mammalian cells, pf-80 increases the proportion of arcs which correlates with the presence of smaller electrical conductances, while large cylindrical pores decline. PFN appears to form arc structures on target membranes that serve as minimally disrupting conduits for GzmB translocation. The role of these arcs in PFN-mediated pathology warrants evaluation where they may serve as novel therapeutic targets.The cytotoxic cell granule-secretory pathway depends on perforin (PFN) to deliver granzyme (Gzm) proteases to the cytosol of target cells where they induce apoptosis and other biological effects, such as inflammation.1 Ring-shaped transmembrane PFN pores hereafter called ‘cylindrical pores'', are presumed to act as the gateway for cytosolic entry, either at the plasma membrane or after endocytosis.2, 3, 4 In either case the highly cationic Gzms are thought to diffuse through these cylindrical pores formed by poly-PFN. Nevertheless, a mechanistic understanding of the phenomenon (how the cationic globular protein exchanges from its carrier proteoglycan, serglycin, to the pore and crosses the plasma and/or vesicular membranes) has been lacking due to limitations in imaging technology and in our detailed understanding of the molecular forms that PFN may adopt following interaction with a target cell plasma membrane.Here we show under conditions where cylindrical pore formation is minimal,5 that granzyme B (GzmB) translocation readily occurs. We previously demonstrated that a prelude to granzyme translocation is PFN-mediated, Ca-independent phosphatidylserine (PS) externalization (flip-flop) measured by annexin-V and lactadherin binding.6 This rapid PS flip-flop also occurs when mouse CD8 cells contact antigen-pulsed target cells. Inasmuch as the proteinaceous cylinders offer a formidable barrier to lipid flow, we have speculated that the observed movement of anionic phospholipids to the external leaflet is due to the formation of proteo-lipidic structures, which consists of oligomerized PFN monomers bearing an arc morphology and plasma membrane lipids.6, 7, 8In the work reported here, the topology of PFN embedded into homogeneous planar bilayers and tumor cell plasma membranes was imaged by atomic force microscopy (AFM) and deep etch electron microscopy (DEEM), respectively. Further, the influence of an anti-human PFN mAb (pf-80) that rescues target cells from necrosis,9 was examined. The AFM data show that PFN forms arcs as well as rings in planar bilayers, while conductance measurements across equivalent membranes in parallel experiments measured functional pore sizes consistent with these varied structures. The pf-80 mAb increased the frequency of arc formation and reduced conductance values. Interestingly, PS flip-flop and granzyme delivery were both increased in target cells after PFN oligomerization was interrupted by the pf-80 mAb. A similar effect was seen in T24 bladder carcinoma cells imaged by DEEM. Treatment with PFN leads to deposition of rings (barrel stave pores) and arcs and the pf-80 mAb increased the ratio of arcs to rings on the surface of these cells. We suggest that the observed protein arcs function as toroidal pores in whole cells, explaining PS flip-flop, and act as focal points for granzyme translocation across lipid bilayer. 相似文献