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141.
142.
Immunolocalization of beta‐proteins and alpha‐keratin in the epidermis of the soft‐shelled turtle explains the lack of formation of hard corneous material
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Lorenzo Alibardi 《Acta zoologica》2015,96(2):218-224
Immunolocalization of beta‐proteins in the epidermis of the soft‐shelled turtle explains the lack of formation of hard corneous material, Acta Zoologica, Stockholm. The corneous layer of soft‐shelled turtles derives from the accumulation of higher ratio of alpha‐keratins versus beta‐proteins as indicated by gene expression, microscopic, immunocytochemical and Western blotting analysis. Type I and II beta‐proteins of 14–16 kDa, indicated as Tu2 and Tu17, accumulate in the thick and hard corneous layer of the hard‐shelled turtle, but only type II is present in the thinner corneous layer of the soft‐shelled turtle. The presence of proline–proline and proline–cysteine–hinge dipeptides in the beta‐sheet region of all type II beta‐proteins so far isolated from the epidermis of soft‐shelled turtles might impede the formation of beta‐filaments and of the hard corneous material. Western blot analysis suggests that beta‐proteins are low to absent in the corneous layer. The ultrastructural immunolocalization of Tu2 and Tu17 beta‐proteins shows indeed that a diffuse labelling is seen among the numerous alpha‐keratin filaments present in the precorneous and corneous layers of the soft epidermis and that no dense corneous material is formed. Double‐labelling experiments confirm that alpha‐keratin prevails on beta‐proteins. The present observations support the hypothesis that the soft material detected in soft‐shelled turtles derives from the prevalent activation of genes producing type II beta‐proteins and high levels of alpha‐keratins. 相似文献
143.
《L'Anthropologie》2015,119(3):303-348
One hundred and forty-eight human remains have been discovered during excavations carried out between 1964 and 2014 in la Caune de l’Arago, in Tautavel, in the Eastern Pyrenees. They come from a detailed stratigraphic context comprising 15 archaeostratigraphic units with human presence, with ages ranging from 550 ka for unit Q at the base, to 400 ka for unit C at the top (OIS 14 to 10). During this long period of time, Man experienced two cold and dry climatic periods (stratigraphic complexes I and III), separated by a humid-temperate period (stratigraphic complex II). Most of the human remains come from units F and G, in stratigraphic complex III, associated with a cold and windy steppic environment. The human remains were mixed with the archaeological material and waste from hunted and consumed fauna. The inventory of human remains comprises a majority of cranial elements, and in particular, the anterior portion of a skull, Arago XXI, discovered on 22 July 1971, which revealed the physical aspect of the first Europeans for the first time. The remains are made up of 5 mandibles, 123 teeth (isolated or still on the alveolar arch), several post-cranial skeletal fragments: 9 upper limb elements, 19 lower limb elements, representing 30 deceased individuals, comprising 18 adults and 12 children. The study of these fossils relates them to Asian and African forms of Homo erectus, as they display common characteristics. This observation raises questions as to the existence of this group in Europe. The contribution of the collection of human fossils from Arago thus presents a threefold interest; paleontological, population-based and behavioural. The multiple remains allow us to assess the biodiversity and the composition of this small population. These remains present original features in comparison to Mauer, the classical Homo heidelbergensis European ancestor. The Arago fossils display archaic characteristics not observed on the Mauer mandible; in particular, the great anteroposterior extension of the convex arch toward the fore, the large proportions of the premolars and of the M2, the high robusticity index of the mandible body, the sub-horizontal alveolar planum and the slightly inclined prominent mylohyoidian line. The face of the skull is not yet reduced to allow for the expansion of the brain, a process which develops at a later stage. The skull is low, with an extended frontal, very marked facial prognathism and a powerful masticatory apparatus with temporal crests and a prominent torus angularis, conveying a pantagonal coronal cross-section, contrasting with the regular convexity observed on the skulls from La Sima de los Huesos and Neanderthals. A comparative analysis with the well-documented population discovered in La Sima de los Huesos shows that the latter fossils are more evolved and are more similar to the Neanderthal shape, and at the same time, not very different from the Mauer mandible. The currently known European human fossils point to the following scenario: Homo georgicus, a similar form to the habilis-rudolfensis group, bearing pre-Oldowan and Oldowan technology, was present at the gateways of Europe approximately 1.8 Ma ago. From 1.2–0.8 Ma onwards, the somewhat fragmentary records from Atapuerca, Elefante, Gran Dolina-TD6, could be related to this first lineage. The first Homo erectus with biface cultures to leave Africa arrived at the gateways of Europe some 1.2 Ma ago, as shown by the discovery of the Kocabaş skull cap in Anatolia, similar to the fossils from Buia in Eritrea and Daka in Ethiopia, dated to about 1 Ma. From 0.55 Ma, the set of 148 human remains, and in particular the skull Arago XXI, point to the presence of a new, well-documented form (distinct from Mauer). We propose to relate these remains to Homo erectus tautavelensis, thereby giving this subspecies a geographic connotation. The morphofunctional and cultural characteristics of Homo erectus tautavelensis represent the stock of a long European lineage, leading to the emergence of Neanderthals. 相似文献
144.
Foliar Extrafloral Nectar of Humboldtia brunonis (Fabaceae), a Paleotropic Ant‐plant,is Richer than Phloem Sap and More Attractive than Honeydew
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Joyshree Chanam Srinivasan Kasinathan Gautam K. Pramanik Amaraja Jagdeesh Kanchan A. Joshi Renee M. Borges 《Biotropica》2015,47(1):1-5
The ant‐plant Humboldtia brunonis secretes extrafloral nectar (EFN) despite the lack of antiherbivore protection from most ants. EFN was richer in composition than phloem sap and honeydew from untended Hemiptera on the plant, suggesting that EFN could potentially distract ants from honeydew, since ants rarely tended Hemiptera on this plant. 相似文献
145.
In polyandrous insect species, males may transfer substances to reduce sperm competition by affecting female sexual receptivity. In this study, we determined the incidence of polyandry in females of Western bean cutworm (WBC), Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), and investigated the influence of both previous female and male mating history on the duration of mating, the female refractory period, and subsequent calling behavior of females under controlled laboratory conditions. The mating status of WBC males influenced mating duration, with copulations involving previously mated males taking longer, possibly related to the time required to produce an ejaculate. The duration of the female refractory period and the onset time of recalling during the scotophase were both affected by female mating history, but not by that of the males. Females had a shorter refractory period and resumed calling activity earlier after their second and third matings than after their first mating. The earlier onset of calling by previously mated females could reduce competition with virgin females and their shorter refractory period could explain the high incidence of polyandry observed in nature. 相似文献
146.
Vazhaikkurichi M. Rajendran Navalpur S. Nanda Kumar Chung M. Tse Henry J. Binder 《The Journal of biological chemistry》2015,290(42):25487-25496
Diarrhea associated with ulcerative colitis (UC) occurs primarily as a result of reduced Na+ absorption. Although colonic Na+ absorption is mediated by both epithelial Na+ channels (ENaC) and Na-H exchangers (NHE), inhibition of NHE-mediated Na+ absorption is the primary cause of diarrhea in UC. As there are conflicting observations reported on NHE expression in human UC, the present study was initiated to identify whether NHE isoforms (NHE2 and NHE3) expression is altered and how Na+ absorption is regulated in DSS-induced inflammation in rat colon, a model that has been used to study UC. Western blot analyses indicate that neither NHE2 nor NHE3 expression is altered in apical membranes of inflamed colon. Na+ fluxes measured in vitro under voltage clamp conditions in controls demonstrate that both HCO3−-dependent and butyrate-dependent Na+ absorption are inhibited by S3226 (NHE3-inhibitor), but not by HOE694 (NHE2-inhibitor) in normal animals. In contrast, in DSS-induced inflammation, butyrate-, but not HCO3−-dependent Na+ absorption is present and is inhibited by HOE694, but not by S3226. These observations indicate that in normal colon NHE3 mediates both HCO3−-dependent and butyrate-dependent Na+ absorption, whereas DSS-induced inflammation activates NHE2, which mediates butyrate-dependent (but not HCO3−-dependent) Na+ absorption. In in vivo loop studies HCO3−-Ringer and butyrate-Ringer exhibit similar rates of water absorption in normal rats, whereas in DSS-induced inflammation luminal butyrate-Ringer reversed water secretion observed with HCO3−-Ringer to fluid absorption. Lumen butyrate-Ringer incubation activated NHE3-mediated Na+ absorption in DSS-induced colitis. These observations suggest that the butyrate activation of NHE2 would be a potential target to control UC-associated diarrhea. 相似文献
147.
Alain Migeon 《ZooKeys》2015,(489):15-24
The family Tetranychidae (spider mites) currently comprises 1,275 species and represents one of the most important agricultural pest families among the Acari with approximately one hundred pest species, ten of which considered major pests. The dataset presented in this document includes all the identified spider mites composing the Jean Gutierrez Collection hosted at the CBGP (Montferrier-sur-Lez, France), gathered from 1963 to 1999 during his career at the Institut de Recherche pour le Développement (IRD). It consists of 5,262 specimens corresponding to 1,564 occurrences (combination species/host plant/date/location) of 175 species. Most specimens were collected in Madagascar and other islands of the Western Indian Ocean, New Caledonia and other islands of the South Pacific and Papuasia. The dataset constitutes today the most important one available on Tetranychidae worldwide. 相似文献
148.
149.
应用双质粒共表达体系提高融合蛋白GGH在毕赤酵母GS115中的表达量 总被引:1,自引:1,他引:0
为实现人胰高血糖素样肽-1-人血清白蛋白融合蛋白 ((GLP-1A2G)2-HSA,简称GGH) 的规模化制备,通过pPICZαB与pPIC9K双质粒共表达体系提高融合蛋白GGH在毕赤酵母中的表达量。首先运用PCR技术扩增出融合蛋白GGH的基因片段,构建了表达质粒pPICZαB-ggh,并电转至经载体pPIC9K-ggh异位整合的GGH分泌型菌株——毕赤酵母GS115/F2;然后采用免疫学方法并结合高浓度抗生素筛选获得高产菌GS115/F3,在30 ℃,3%甲醇诱导80 h后GGH的表达量达到了491 m 相似文献
150.
Chuanxing Wang Si Yun Shu Zhouyi Guo Ye Feng Cai Xinmin Bao Changchun Zeng Bingyi Wu Ziyou Hu Xuemei Liu 《Journal of biomedical science》2011,18(1):34