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31.
Rana tigrina andTomopterna breviceps occur as sympatric species at Dharwad, India. Sexually mature males produce advertisement calls. The advertisement call of
both the species consist of a number of calls produced in series forming a call group. Each call group ofRana tigrina comprises 10–40 calls, whereas that ofTomopterna breviceps consists 13–141 calls. Each call consists of a pulse group with variable number of pulses which lack pulse interval. Calls
of both the species exhibit similarities in (i) call consisting of series of calls with a pulse group in each call, (ii) absence
of pulse interval within the pulse group, (iii) the amplitude of the first pulse being always small, and (iv) the frequency
spectrum beginning from 200 Hz. Based on the similarities in the spectral features of the calls, it is suggested that the
two species may be closely related to each other. 相似文献
32.
Molecular tectonic model of virus structural transitions: the putative cell entry states of poliovirus
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Belnap DM Filman DJ Trus BL Cheng N Booy FP Conway JF Curry S Hiremath CN Tsang SK Steven AC Hogle JM 《Journal of virology》2000,74(3):1342-1354
Upon interacting with its receptor, poliovirus undergoes conformational changes that are implicated in cell entry, including the externalization of the viral protein VP4 and the N terminus of VP1. We have determined the structures of native virions and of two putative cell entry intermediates, the 135S and 80S particles, at approximately 22-A resolution by cryo-electron microscopy. The 135S and 80S particles are both approximately 4% larger than the virion. Pseudoatomic models were constructed by adjusting the beta-barrel domains of the three capsid proteins VP1, VP2, and VP3 from their known positions in the virion to fit the 135S and 80S reconstructions. Domain movements of up to 9 A were detected, analogous to the shifting of tectonic plates. These movements create gaps between adjacent subunits. The gaps at the sites where VP1, VP2, and VP3 subunits meet are plausible candidates for the emergence of VP4 and the N terminus of VP1. The implications of these observations are discussed for models in which the externalized components form a transmembrane pore through which viral RNA enters the infected cell. 相似文献
33.
Conclusions The efficacy of a magnetic field to act as a permeation enhancer was demonstrated. Because in vitro and in vivo performance
of F1 and F2 were comparable, the substitution of chemical enhancers by magnetic field in transdermal delivery systems appears
to be possible. 相似文献
34.
PTHrP is necessary for the formation of the embryonic mammary gland and, in its absence, the embryonic mammary bud fails to form the neonatal duct system. In addition, PTHrP is produced by the breast during lactation and contributes to the regulation of maternal calcium homeostasis during milk production. In this study, we examined the role of PTHrP during post-natal mammary development. Using a PTHrP-lacZ transgenic mouse, we surveyed the expression of PTHrP in the developing post-natal mouse mammary gland. We found that PTHrP expression is restricted to the basal cells of the gland during pubertal development and becomes expressed in milk secreting alveolar cells during pregnancy and lactation. Based on the previous findings that overexpression of PTHrP in cap and myoepithelial cells inhibited ductal elongation during puberty, we predicted that ablation of native PTHrP expression in the post-natal gland would result in accelerated ductal development. To address this hypothesis, we generated two conditional models of PTHrP-deficiency specifically targeted to the postnatal mammary gland. We used the MMTV-Cre transgene to ablate the floxed PTHrP gene in both luminal and myoepithelial cells and a tetracycline-regulated K14-tTA;tetO-Cre transgene to target PTHrP expression in just myoepithelial and cap cells. In both models of PTHrP ablation, we found that mammary development proceeds normally despite the absence of PTHrP. We conclude that PTHrP signaling is not required for normal ductal or alveolar development. 相似文献
35.
Experiments involving beta-catenin loss- and gain-of-function in the mammary gland have decisively demonstrated the role of this protein in normal alveologenesis. However, the relationship between hormonal and beta-catenin signaling has not been investigated. In this study, we demonstrate that activated beta-catenin rescues alveologenesis in progesterone receptor (PR; Pgr)-null mice during pregnancy. Two distinct subsets of mammary cells respond to expression of DeltaN89beta-catenin. Cells at ductal tips are inherently beta-catenin-responsive and form alveoli in the absence of PR. However, PR activity confers beta-catenin responsiveness to progenitor cells along the lateral ductal borders in the virgin gland. Once activated by beta-catenin, responding cells switch on an alveolar differentiation program that is indistinguishable from that observed in pregnancy and is curtailed by PR signaling. 相似文献
36.
Shivanand M. Pudakalakatti Abhinav Dubey Garima Jaipuria U. Shubhashree Satish Kumar Adiga Detlef Moskau Hanudatta S. Atreya 《Journal of biomolecular NMR》2014,58(3):165-173
We present a new method for rapid NMR data acquisition and assignments applicable to unlabeled (12C) or 13C-labeled biomolecules/organic molecules in general and metabolomics in particular. The method involves the acquisition of three two dimensional (2D) NMR spectra simultaneously using a dual receiver system. The three spectra, namely: (1) G-matrix Fourier transform (GFT) (3,2)D [13C, 1H] HSQC–TOCSY, (2) 2D 1H–1H TOCSY and (3) 2D 13C–1H HETCOR are acquired in a single experiment and provide mutually complementary information to completely assign individual metabolites in a mixture. The GFT (3,2)D [13C, 1H] HSQC–TOCSY provides 3D correlations in a reduced dimensionality manner facilitating high resolution and unambiguous assignments. The experiments were applied for complete 1H and 13C assignments of a mixture of 21 unlabeled metabolites corresponding to a medium used in assisted reproductive technology. Taken together, the experiments provide time gain of order of magnitudes compared to the conventional data acquisition methods and can be combined with other fast NMR techniques such as non-uniform sampling and covariance spectroscopy. This provides new avenues for using multiple receivers and projection NMR techniques for high-throughput approaches in metabolomics. 相似文献
37.
Pranoti Hiremath Michael Bauer Hui-Wen Cheng Kazumasa Unno Ronglih Liao Susan Cheng 《Journal of visualized experiments : JoVE》2014,(83)
Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software. 相似文献
38.
Fungal gene expression in early symbiotic interactions between Laccaria bicolor and red pine 总被引:1,自引:1,他引:0
Podila G.K. Zheng J. Balasubramanian S. Sundaram S. Hiremath S. Brand J.H. Hymes M.J. 《Plant and Soil》2002,244(1-2):117-128
Ectomycorrhizas are mutualistic symbiotic organs formed by interaction between plant roots and fungi. Mycorrhizal initiation, development and functional maintenance involve morphological changes that are mediated by activation and suppression of several fungal and plant genes. During the pre-infection stage, a harmonized cross-talk takes place between the symbionts, to determine their compatibility. Upon mutual recognition, the symbionts initiate further physiological and morphological changes essential for the formation of the symbiotic organ. In order to understand the molecular mechanisms underlying these events, we developed an interaction-specific cDNA library from Laccaria bicolor that represents fungal genes regulated by its interaction with Pinus resinosa roots. Membrane array analyses of these cDNAs suggested that a wide variety of genes are involved in the pre-infection stage processes. 相似文献
39.
H. N. Murthy S. C. Hiremath S. S. Salimath 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,85(5):587-592
Summary Genome affinities were analyzed at meiosis in C-banded metaphase-I cells of wheat x Ae. Sharonensis hybrid plants. The results showed that the most frequent type of pairing occurred between chromosomes of the A and D genomes in all plants, as well as in cells with different numbers of associations. These findings clearly indicated that Ae. Sharonensis can be excluded as the donor of the B genome of wheat. 相似文献
40.
R. D. Kanamadi H. Schneider C. R. Hiremath C. S. Jirankali 《Journal of biosciences》1993,18(2):239-245
The period of calling activity ofPolypedates maculatus lies between April and October. Males possess an indistinct subgular vocal sac which turns yellow during the breeding season.
Mating calls type I, type II and distress calls have been identified. Mating calls type I and type II consist of a single
pulse group. Type I call comprises of 7–22 pulses, whereas type II call consists of 4–6 pulses. Pulses are short. The frequency
spectrum is broad and continuous. Distress calls, with 6 hormonics, are given by the females with their mouth open. 相似文献