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Use of the open rhinoplasty technique (ORT) in certain nasal and septal deformities has proven to be an invaluable asset in the rhinoplasty armamentarium of the authors. Primarily owing to the markedly increased exposure with this technique, more accurate assessment of the deformities is possible and additional or improved surgical maneuvers become available, particularly in the tip. Sculpting the entire cartilaginous and/or bony vault, as well as correcting difficult septal malalignments, can be carried out under better direct vision with greater precision, accuracy, and predictability. This has led to improved and more consistent final results. Previous criticisms of unsightly columellar scars have been virtually eliminated through the use of improved surgical techniques and simple magnification. Overall, open rhinoplasty technique can provide many distinct advantages in certain nasal deformities with no real disadvantages over conventional closed techniques.  相似文献   

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Gitlin L  Colonna M 《Cell research》2007,17(11):898-900
In order to survive, all organisms must guard against viral infections. Recognition of viruses is accomplished via multiple sensors. Many mammalian proteins can recognize viral products, such as double-stranded RNA (dsRNA), yet few of them are known to induce interferon, the central antiviral messenger. Since interferon is indispensable for successful antiviral defense [1], the interferon-inducing sensors have been of particular interest. However, a clear understanding of such sensors has been elusive, and the first well-established sensor family, the toll-like receptors (TLRs), was described relatively recently [2]. Antiviral TLRs are positioned in the endosomes, where they report the appearance of viral genetic material (DNA, single-and double-stranded RNA). However, the question of potential virus sensors in the cytoplasm was left open. Given the particular effectiveness ofintracellular dsRNA at inducing interferon, it was suspected that dsRNA-binding sensor molecules would be found in the cytoplasm.[第一段]  相似文献   

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A fresh look at the temporal dynamics of binocular rivalry   总被引:3,自引:0,他引:3  
Human observers viewed dichoptic orthogonal sine-wave gratings and indicated when exclusive visibility occurred in either eye. Contrast was held constant in one eye and was increased or decreased in the other eye for a number of alternation cycles (continuous presentation) or for only the duration of a single period of exclusive visibility (synchronous presentation). The synchronous presentation condition allowed us to identify the differing effects of contrast during the suppressed and during the dominant periods. Mixed phases were recorded as distinct from suppressed and dominant phases, and new classifications of compound-dominant and compound-suppressed phases are defined. The results indicate that binocular rivalry responds to stimulus contrast in two ways. 1) The duty-cycle of dominance and suppression is determined by the relative image contrast between the two eyes, with dominance of the higher contrast image being favored, and 2) the overall rate of alternation is driven by monocular image contrast during the suppressed phase (increased monocular contrast increases the alternation rate) and to a lesser extent by monocular contrast during the dominant phase (increased monocular contrast decreases the rate). A model is developed to reflect these ideas. These results support a reciprocal inhibition oscillator as the underlying mechanism of binocular rivalry.  相似文献   

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Schulze A 《EMBO reports》2011,12(4):289-291
The Institute for Research in Biomedicine (IRB) Barcelona meeting on Cancer Metabolism took place in November 2010. It was organized with the support of the Banco Bilbao Vizcaya Argentaria Foundation and offered an outstanding line-up of acclaimed speakers within an intimate setting that allowed plenty of opportunity for informal interactions.  相似文献   

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The rock record provides us with unique evidence for testing models as to when and where cellular life first appeared on Earth. Its study, however, requires caution. The biogenicity of stromatolites and 'microfossils' older than 3.0 Gyr should not be accepted without critical analysis of morphospace and context, using multiple modern techniques, plus rejection of alternative non-biological (null) hypotheses. The previous view that the co-occurrence of biology-like morphology and carbonaceous chemistry in ancient, microfossil-like objects is a presumptive indicator of biogenicity is not enough. As with the famous Martian microfossils, we need to ask not 'what do these structures remind us of?', but 'what are these structures?' Earth's oldest putative 'microfossil' assemblages within 3.4-3.5 Gyr carbonaceous cherts, such as the Apex Chert, are likewise self-organizing structures that do not pass tests for biogenicity. There is a preservational paradox in the fossil record prior to ca 2.7 Gyr: suitable rocks (e.g. isotopically light carbonaceous cherts) are widely present, but signals of life are enigmatic and hard to decipher. One new approach includes detailed mapping of well-preserved sandstone grains in the ca 3.4 Gyr Strelley Pool Chert. These can contain endolithic microtubes showing syngenicity, grain selectivity and several levels of geochemical processing. Preliminary studies invite comparison with a class of ambient inclusion trails of putative microbial origin and with the activities of modern anaerobic proteobacteria and volcanic glass euendoliths.  相似文献   

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From which host did the most malignant human malaria come: birds, primates, or rodents? When did the transfer occur? Over the last half century, these have been some of the questions up for debate about the origin of Plasmodium falciparum, the most common and deadliest human malaria parasite, which is responsible for at least one million deaths every year. Recent findings bring elements in favor of a transfer from great apes, but are these evidences really solid? What are the grey areas that remain to be clarified? Here, we examine in depth these new elements and discuss how they modify our perception of the origin and evolution of P. falciparum. We also discuss the perspectives these new discoveries open.  相似文献   

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Bioturbation: a fresh look at Darwin's last idea   总被引:13,自引:0,他引:13  
Bioturbation refers to the biological reworking of soils and sediments, and its importance for soil processes and geomorphology was first realised by Charles Darwin, who devoted his last scientific book to the subject. Here, we review some new insights into the evolutionary and ecological role of bioturbation that would have probably amazed Darwin. In modern ecological theory, bioturbation is now recognised as an archetypal example of 'ecosystem engineering', modifying geochemical gradients, redistributing food resources, viruses, bacteria, resting stages and eggs. From an evolutionary perspective, recent investigations provide evidence that bioturbation had a key role in the evolution of metazoan life at the end of the Precambrian Era.  相似文献   

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Alpha-actinin revisited: a fresh look at an old player   总被引:14,自引:0,他引:14  
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