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31.
The locomotion of Babakotia radofilai inferred from epiphyseal and diaphyseal morphology of the humerus and femur 下载免费PDF全文
Damiano Marchi Christopher B. Ruff Alessio Capobianco Katherine L. Rafferty Michael B. Habib Biren A. Patel 《Journal of morphology》2016,277(9):1199-1218
Palaeopropithecids, or “sloth lemurs,” are a diverse clade of large‐bodied Malagasy subfossil primates characterized by their inferred suspensory positional behavior. The most recently discovered genus of the palaeopropithecids is Babakotia, and it has been described as more arboreal than Mesopropithecus, but less than Palaeopropithecus. In this article, the within‐bone and between‐bones articular and cross‐sectional diaphyseal proportions of the humerus and femur of Babakotia were compared to extant lemurs, Mesopropithecus and Palaeopropithecus in order to further understand its arboreal adaptations. Additionally, a sample of apes and sloths (Choloepus and Bradypus) are included as functional outgroups composed of suspensory adapted primates and non‐primates. Results show that Babakotia and Mesopropithecus both have high humeral/femoral shaft strength proportions, similar to extant great apes and sloths and indicative of forelimb suspensory behavior, with Babakotia more extreme in this regard. All three subfossil taxa have relatively large femoral heads, also associated with suspension in modern taxa. However, Babakotia and Mesopropithecus (but not Palaeopropithecus) have relatively small femoral head surface area to shaft strength proportions suggesting that hind‐limb positioning in these taxa during climbing and other behaviors was different than in extant great apes, involving less mobility. Knee and humeral articular dimensions relative to shaft strengths are small in Babakotia and Mesopropithecus, similar to those found in modern sloths and divergent from those in extant great apes and lemurs, suggesting more sloth‐like use of these joints during locomotion. Mesopropithecus and Babakotia are more similar to Choloepus in humerofemoral head and length proportions while Palaeopropithecus is more similar to Bradypus. These results provide further evidence of the suspensory adaptations of Babakotia and further highlight similarities to both extant suspensory primates and non‐primate slow arboreal climbers and hangers. J. Morphol. 277:1199–1218, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
32.
V A Ruff A W Yem P L Munns L D Adams I M Reardon M R Deibel K L Leach 《The Journal of biological chemistry》1992,267(30):21285-21288
Heat shock protein 56 (hsp56) has been shown to be involved in two cellular pathways, as an immunophilin for FK506 and as a component of steroid receptor complexes. To help define its role in these cellular pathways, we have developed UPJ56, a polyclonal antibody raised against hsp56 purified from Jurkat cells. In Western blot experiments, hsp56 was highly expressed in rat thymus, liver, and spleen, with low levels in lung and muscle. In immunofluorescence experiments using untreated LLC-PK1 cells, fibrillar staining was seen in the cytoplasm, suggesting a cytoskeletal localization of hsp56. The nuclei were brightly stained, except for the nucleoli. Confocal microscopy demonstrated that the staining was present in all planes of the nucleus. These results suggest that hsp56 is expressed in tissues enriched in steroid receptors and is highly expressed in tissues involved in T cell function. Furthermore, the localization of hsp56 with the cytoskeleton and throughout the nucleus is consistent with its association with steroid receptor complexes. 相似文献
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Photosynthetica - Redox polymer/protein biophotoelectrochemistry was used to analyse forward electron transfer of isolated PSII complexes with natural PsbA-variants. PsbA1- or PsbA3-PSII was... 相似文献
35.
Kenneth A. Callicott Vala Fririksdttir Jarle Reiersen Ruff Lowman Jean-Robert Bisaillon Eggert Gunnarsson Eva Berndtson Kelli L. Hiett David S. Needleman Norman J. Stern 《Applied microbiology》2006,72(9):5794-5798
Campylobacter jejuni is a major cause of bacterial food-borne infection in the industrial world. There is evidence that C. jejuni is present in eggs and hatchery fluff, opening the possibility for vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, since breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. While Campylobacter was not detected in all grandparent flocks, 13 of the 16 egg import lots consisted of eggs gathered from one or more Campylobacter-positive grandparent flocks. No evidence of Campylobacter was found by PCR in any of the 10 relevant quarantine hatchery fluff samples examined, and no Campylobacter was isolated from the parent birds through 8 weeks, while they were still in quarantine rearing facilities. After the birds were moved to less biosecure rearing facilities, Campylobacter was isolated, and 29 alleles were observed among the 224 isolates studied. While three alleles were found in both Sweden and Iceland, in no case was the same allele found both in a particular grandparent flock and in its progeny. We could find no evidence for vertical transmission of Campylobacter to the approximately 60,000 progeny parent breeders that were hatched from eggs coming from Campylobacter-positive grandparent flocks. If vertical transmission is occurring, it is not a significant source for the contamination of chicken flocks with Campylobacter spp. 相似文献
36.
Cell Division and Prophage Induction in Escherichia coli: Studies of Nucleotide Levels 总被引:9,自引:6,他引:3 下载免费PDF全文
Cell division and prophage repression in the Escherichia coli mutant, T-44, are very sensitive to the levels of certain purine and pyrimidine derivatives in the media. The hypothesis that a change in the level of an adenine derivative in the small molecule pool of this strain was responsible for prophage induction and filament formation was tested. The nucleoside triphosphate pools in T-44 and C-600 nonlysogenic and lysogenic strains were labeled in experiments with (32)P and (33)P. Cultures were mixed, and the nucleotides were isolated. When adenine was present, the level of adenosine triphosphate (ATP) in T-44 compared to C-600 (as indicated by the isotope ratio) was increased up to twofold. Most of the other nucleotides increased but not to the same degree. In the lysogenic strain guanosine triphosphate and deoxycytidine triphosphate showed increases comparable to ATP, whereas increases noted in the deoxynucleotides in T-44 +/- lambda with adenine present were less. In experiments where T-44 and C-600 were incubated with (3)H- and (14)C-adenine, the levels of several compounds, including ATP, were slightly elevated in T-44. The combined data suggest that cultures of T-44 +/- lambda, grown in the presence of adenine, show a preferential increase in the level of ATP when compared to C-600 +/- lambda, but the increase in relation to the other nucleotides is less than twofold. In the experiment with (3)H- and (14)C-adenine, the level of inosine was found to be increased in T-44 relative to C-600. Cyclic AMP, when added to cultures of T-44 under various conditions, had no effect on prophage induction. Intracellular and extracellular levels of cyclic AMP in T-44 compared to C-600, incubated with had-acidin, guanosine, and cytidine (HGC) or with HGC plus adenine, were not significantly different. No compelling evidence for altered nucleotide metabolism in T-44 +/- lambda as a cause of prophage induction or filament formation was obtained. 相似文献
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Estella A. Newcombe Kiersten M. Ruff Ashish Sethi Angelique R. Ormsby Yasmin M. Ramdzan Archa Fox Anthony W. Purcell Paul R. Gooley Rohit V. Pappu Danny M. Hatters 《Journal of molecular biology》2018,430(10):1442-1458
Soluble huntingtin exon 1 (Httex1) with expanded polyglutamine (polyQ) engenders neurotoxicity in Huntington's disease. To uncover the physical basis of this toxicity, we performed structural studies of soluble Httex1 for wild-type and mutant polyQ lengths. Nuclear magnetic resonance experiments show evidence for conformational rigidity across the polyQ region. In contrast, hydrogen–deuterium exchange shows absence of backbone amide protection, suggesting negligible persistence of hydrogen bonds. The seemingly conflicting results are explained by all-atom simulations, which show that Httex1 adopts tadpole-like structures with a globular head encompassing the N-terminal amphipathic and polyQ regions and the tail encompassing the C-terminal proline-rich region. The surface area of the globular domain increases monotonically with polyQ length. This stimulates sharp increases in gain-of-function interactions in cells for expanded polyQ, and one of these interactions is with the stress-granule protein Fus. Our results highlight plausible connections between Httex1 structure and routes to neurotoxicity. 相似文献
39.
J. Ruff T. Hitzler U. Rein A. Ritter A. M. Cook 《Applied microbiology and biotechnology》1999,52(3):446-450
Highly substituted arenesulfonates are chemically stable compounds with a range of industrial applications, and they are
widely regarded as being poorly degradable. We did enrichment cultures for bacteria able to utilise the sulfonate moiety of
14 compounds, and we obtained mixed cultures that were able to desulfonate each compound. The products formed were usually
identified as the corresponding phenol, but because we could not obtain pure cultures, we followed up these findings with
quantitative work in pure cultures of, e.g., Pseudomonas putida S-313, which generated the same phenols from the compounds studied. Many of these phenols are known to be biodegradable,
or to be subject to binding to soil components. We thus presume that the capacity to degrade aromatic sulfonates extensively
is widespread in the environment, even though the degradative capacity is spread over several organisms and conditions.
Received: 9 February 1999 / Revision received: 7 April 1999 / Accepted: 9 April 1999 相似文献
40.
Cells use the singular properties of different channels to produce unique electrical songs. 总被引:2,自引:0,他引:2 下载免费PDF全文
R L Ruff 《Biophysical journal》1998,74(6):2745-2746